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wizyta

od 2020-09-20

Prof. dr hab. Stefan Jurga  | 1994-10 - obecnie

Kierownik Zakładu Fizyki Makromolekularnej w latach 1994-2016

   WF UAM pokój: 138 / CNBM UAM      +48 61-829-5290       stjurga@amu.edu.pl

  0000-0002-1665-6077     2132982 / E-8862-2017     7004205616  

Zainteresowania naukowe:
Główne zainteresowania badawcze prof. S. Jurgi koncentrują się na strukturze i dynamice materii miękkiej analizowanej za pomocą obrazowania NMR, metod rozproszeniowych (SAXS, WAXS), mikroskopii elektronowej, sił atomowych oraz optycznej, relaksacji oraz dyfuzji NMR, technik modelowania komputerowego, spektroskopi dielektrycznej i FTIR. Profesor Jurga jest autorem i współautorem 190 publikacji naukowych w renomowanych czasopismach o zasięgu krajowym i międzynarodowym. Uczestniczył w wielu międzynarodowych projektach badawczych, był promotorem 20 doktorantów.

Ma bogate doświadczenie we współpracy międzynarodowej, był m.in. profesorem wizytującym w Cornell University, Uniwersytecie Stanowym Północnej Karoliny w USA, w Uniwersytecie Południowej Afryki w Pretorii w RPA, w Centrum Badań Atomowych w Saclay pod Paryżem. Prof. Jurga był laureatem Fundacji Maxa Plancka jako stypendysta w Instytucie Maxa Plancka do badań polimerowych w Moguncji, Niemcy, pracował na Uniwersytecie Illinois w Urbana Champaign, USA, w Instytucie Jozefa Stefana w Słowenii, i w innych instytucjach.

Publikacje      Projekty      Doktorzy      Magistrowie      Licencjusze      Seminaria


317.

Maciejewska B.M., Wychowaniec J.K., Woźniak-Budych M., Popenda Ł., Warowicka A., Golba K., Litowczenko J., Fojud Z., Wereszczyńska B., Jurga S.

UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications.

Science and Technology of Advanced Materials, 20(1), 979-991 (2019)

DOI: 10.1080/14686996.2019.1667737   (Pobrane:  2020-06-04)


316.

Rębiś T., Falkowski M., Kryjewski M., Popenda Ł., Sobotta Ł., Jurga S., Marszall M.P., Mielcarek J., Milczarek G., Goślinski T.

Single-walled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode for sensitive determination of nitrites The metallation reaction of 2-[2-(3,5-dibutoxycarbonylphenoxy)ethoxy]ethylsulfanyl-substituted porphyrazine with manganese and nickel salts led to novel porhyrazine derivatives with d-block metal ions in the core. Voltammetric studies of nickel(II) porphyrazine in organic electrolyte revealed the existence of well-defined one-electron ligand-based reductions and ligand-based one-electron oxidation redox pairs. Manganese porphyrazine however, presented both metal-based and ligand-based reductions and oxidation processes. The glassy carbon electrode with deposited single-walled carbon nanotube/sulfanyl porphyrazine hybrids was examined for the electrocatalytic oxidation of nitrites. The results indicated that when nickel(II) porphyrazine is present, it significantly contributes to the promotion of the electrocatalytic current for nitrites oxidation. The response of the proposed modified electrode was linear considering the nitrites concentration in the range of 5-200 mu M and with a detection limit (LOD) and quantitation limit (LOQ) equal to 1.08 and 3.60 mu M, respectively. The proposed voltammetric sensor was also applied for the determination of nitrites in tap water and mineral water samples.

Dyes and Pigments, 171, 107660 (2019)

DOI: 10.1016/j.dyepig.2019.107660   (Pobrane:  2020-12-30)


315.

Grześkowiak B.F., Tuśnio K., Woźniak A., Szalata M., Lipiński D., Jurga S., Słomski R.

Transgenic plant detection using an AuNPs based SPR biosensor The intensive development and commercialization of genetically modified plants observed over the last decade has led to the development of transgenic detection methods that are rapid and sensitive. Among the strategies used for the detection/monitoring of genetically modified organisms (GMOs), surface plasmon resonance (SPR) meets the necessary criteria. This optical technique measures the changes in the refractive index in the vicinity of thin metal layers (i.e., gold) in response to biomolecular interactions occurring at a flat metal-solution interface. Additionally, it allows the application of functionalized gold nanoparticles (AuNPs) in SPR research to enhance the signal intensity. In the present study, an SPR method, enhanced by the application of AuNPs, was developed to detect transgenic tobacco plants carrying a Streptococcus mutans antigen. The basis for the detection of the target DNA was the hybridization between the genomic DNA isolated from the leaves, stems, and roots of the transgenic tobacco and the biotinylated oligonucleotide probes immobilized onto a streptavidin (SA) sensor chip. SA-functionalized AuNPs coated with a second type of biotinylated probe were applied to increase the sensitivity of the detection method. Analysis of the results indicated that the constructed SPR-based sensor chip can potentially recognize complementary standard fragments (nonamplified genomic DNA) at concentrations as low as 1 pM. Thus, nonamplified transgenic DNA was detected using a label-free and real-time AuNPs-enhanced SPR biosensing method. This unique approach could be used to detect GMOs with high efficiency, even at a low detection limit, high repeatability, and with less time and a lower cost needed for each analysis.

Biosensors-Basel, 9(4), 116 (2019)

DOI: 10.3390/bios9040116   (Pobrane:  2020-12-30)


314.

Kertmen A., Przysiecka Ł., Coy E., Popenda Ł., Andruszkiewicz R., Jurga S., Milewski S.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

Langmuir, 35(44), 14397-14397 (2019)

DOI: 10.1021/acs.langmuir.9b03088   (Pobrane:  2020-12-30)


313.

Warowicka A., Popenda Ł., Bartkowiak G., Musidlak O., Litowczenko-Cybulska J., Kuźma D., Nawrot R., Jurga S., Goździcka-Józefiak A.

Protoberberine compounds extracted from Chelidonium majus L. as novel natural photosensitizers for cancer therapy Background: It has been shown that secondary metabolites occur in Chelidonium majus L. (C. majus) crude extract and milky sap (alkaloids such as berberine, coptisine, chelidonine, chelerythrine, sanguinarine, and protopine) are biologically active compounds with a wide spectrum of pharmacological functions. Berberine, an isoquinoline alkaloid extracted from plants, possesses a wide range of biological activities, including inhibition of growth of a variety of cancer cell lines.

Purpose and study design: In the present study, we investigated the potential anticancer effect of a protoberberine alkaloidal fraction (BBR-F) isolated from the medicinal plant C. majus on HeLa and C33A cervical cancer cells after light irradiation (PDT treatment).

Methods: BBR-F was prepared from an ethanolic extract of stems of C. majus. Identification of alkaloidal compounds was performed using high-performance liquid chromatography - mass spectrometry (HPLC/ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy. BBR-F was then biologically evaluated for its anticancer properties. Cytotoxic activity after PDT treatment and without light irradiation (dark cytotoxicity) was determined by colorimetric WST-1 assay. The impact of the protoberberine alkaloidal fraction on the morphology and function of the cells was assessed by fluorescence and confocal microscopy as well as by flow cytometric analysis. To investigate the proinflammatory effect of the extracted natural BBR-F, nitric oxide concentration was determined using the Griess method.

Results: An effective reduction in HeLa and C33A cell viability was observed after PDT treatment of BBR-F treated cells. Furthermore, microscopic analysis identified various morphological changes in the studied cells that occurred during apoptosis. Apoptosis of HeLa and C33A cells was also characterized by biochemical changes in cell membrane composition, activation of intracellular caspases, disruption of the mitochondrial membrane potential (Delta psi m) and reactive oxygen species (ROS) generation.

Conclusion: Our results strongly suggest that the components of the natural plant protoberberine fraction (BBRF) extracted from C. majus may represent promising novel photosensitive agents and can be applied in cancer photodynamic therapy as natural photosensitizers.

Phytomedicine, 64, 152919 (2019)

DOI: 10.1016/j.phymed.2019.152919   (Pobrane:  2020-12-30)


312.

Litowczenko J., Maciejewska B.M., Wychowaniec J.K., Kościnski M., Jurga S., Warowicka A.

Groove-patterned surfaces induce morphological changes in cells of neuronal origin It is already known that cells respond strongly to topography and chemistry of 2D surfaces. In this work we study cell-material interactions; in particular, we investigated the attachment and alignment of SH-SY5Y cells of neuronal origin on grooved-patterns made from Silicon (Si) and Gold (Au). The Au-Si groove-pattern stimulated 93% of SH-SY5Y cells to differentiate into neuroblast-like type (N-type) in 2 days and outgrown neurites exhibited strong anisotropy along the grooves with 90% of cells having one or two neurites. In comparison, random distribution of morphology type, neurite number, and alignment were observed on control flat surfaces (Si and Au). We further show that designed Au-Si groove-patterns can be used to form reversed groove patterns on polycarolactone surface via soft lithography approach. Sixty-nine percentage of SH-SY5Y cells aligned along the obtained reversed groove patterns of the same dimensional characteristics to Si-Au grooves. In particular, this work demonstrated that the Au-Si grooves pattern stimulates neurite polarity, elongation, and morphological differentiation of neuroblastoma cells without any exogenous supply of growth factors or stimulants in just 2 days, which can lead to selective procedure of obtaining homologous population of neuron-like cells for future nerve regeneration therapies.

Journal of Biomedical Materials Research part A, 107(10), 2244-2256 (2019)

DOI: 10.1002/jbm.a.36733   (Pobrane:  2020-12-30)


311.

Szutkowski K., Sikorska E., Bakanovych I., Choudhury A.R., Perdih A., Jurga S., Novic M., Zhukov I.

Structural analysis and dynamic processes of the transmembrane segment inside different micellar environments-implications for the TM4 fragment of the bilitranslocase protein The transmembrane (TM) proteins are gateways for molecular transport across the cell membrane that are often selected as potential targets for drug design. The bilitranslocase (BTL) protein facilitates the uptake of various anions, such as bilirubin, from the blood into the liver cells. As previously established, there are four hydrophobic transmembrane segments (TM1-TM4), which constitute the structure of the transmembrane channel of the BTL protein. In our previous studies, the 3D high-resolution structure of the TM2 and TM3 transmembrane fragments of the BTL in sodium dodecyl sulfate (SDS) micellar media were solved using Nuclear Magnetic Resonance (NMR) spectroscopy and molecular dynamics simulations (MD). The high-resolution 3D structure of the fourth transmembrane region (TM4) of the BTL was evaluated using NMR spectroscopy in two different micellar media, anionic SDS and zwitterionic DPC (dodecylphosphocholine). The presented experimental data revealed the existence of an alpha-helical conformation in the central part of the TM4 in both micellar media. In the case of SDS surfactant, the alpha-helical conformation is observed for the Pro258-Asn269 region. The use of the zwitterionic DPC micelle leads to the formation of an amphipathic alpha-helix, which is characterized by the extension of the central alpha-helix in the TM4 fragment to Phe257-Thr271. The complex character of the dynamic processes in the TM4 peptide within both surfactants was analyzed based on the relaxation data acquired on N-15 and P-31 isotopes. Contrary to previously published and present observations in the SDS micelle, the zwitterionic DPC environment leads to intensive low-frequency molecular dynamic processes in the TM4 fragment.

International Journal of Molecular Sciences, 20(17), 4172 (2019)

DOI: 10.3390/ijms20174172   (Pobrane:  2020-12-30)


310.

Matuła K., Richter Ł., Janczuk-Richter M., Nogala W., Grzeszkowiak M., Peplińska B., Jurga S., Wyroba E., Suski S., Bilski H., Silesian A., Bluyssen H.A.R., Derebecka N., Wesoły J., Łoś J.M., Łoś M., Decewicz P., Dziewit Ł., Paczesny J., Hołyst R.

Phenotypic plasticity of Escherichia Coli upon exposure to physical stress induced by ZnO nanorods Evolution of bacteria to selective chemical pressure (e.g. antibiotics) is well studied in contrast to the influence of physical stressors. Here we show that instantaneous physical stress in a homogeneous environment (without concentration gradient) induces fast adaptation of Escherichia coli. We exposed E. coli to a large number of collisions of around 10(5) per bacterium per second with sharp ZnO nanorods. The pressure exerted on the bacterial cell wall was up to 10 GPa and induced phenotype changes. The bacteria's shape became more spherical, the density of their periplasm increased by around 15% and the average thickness of the cell wall by 30%. Such E. coli cells appeared almost as Gram-positive bacteria in the standard Gram staining. Additionally, we observed a combination of changes occurring at the genomic level (mutations identified in form of single nucleotide polymorphisms) and downregulation of expression of 61 genes encoding proteins involved in beta-oxidation of fatty acids, glycolysis, the citric acid cycle, as well as uptake of amino acids and enzyme cofactors. Thus, we show that bacteria undergo phenotypic changes upon instantaneous, acute physical stress without any obviously available time for gradual adaptation.

Scientific Reports, 9, 8575 (2019)

DOI: 10.1038/s41598-019-44727-w   (Pobrane:  2020-12-30)


309.

Grabowska M., Wawrzyniak D., Rolle K., Chomczyński P., Oziewicz S., Jurga S., Barciszewski J.

Let food be your medicine: nutraceutical properties of lycopene Currently, an increase in the awareness of a healthy lifestyle has been observed in society. People are seeking added health benefits from their dietary intake. Thus, functional foods with supplemented components that promote wellness are becoming popular. Lycopene is a carotenoid that gives vegetables and fruits their red color. Due to its chemical structure, lycopene acts as an antioxidant, which is the basis for its health-promoting properties. Oxidative stress is recognized as an important agent of many chronic diseases; thus, lycopene appears to be a universal medicine. Lycopene has the greatest antioxidant potential among carotenoids. Nutraceutical effects of lycopene have been reported for patients with cancer, infertility, metabolic syndrome and liver damage. Therefore, its supplementation can function as a proper causative treatment of disease. In this review, we highlight primary research and clinical trials involving lycopene and its impact on human health.

Food & Function, 10(6), 3090-3102 (2019)

DOI: 10.1039/c9fo00580c   (Pobrane:  2020-12-30)


308.

Grabowska M., Wawrzyniak D., Rolle K., Chomczyński P., Oziewicz S., Jurga S., Barciszewski J.

Lanthanides and tissue engineering strategies for bone regeneration In this review, significant applications of lanthanides and their compounds in bone tissue engineering are described, with an emphasis on coordination compounds based on wide variety of ligands, crystalline structure and their properties, stability as well as cytotoxicity. The current challenges and several scientific discoveries related to the use of lanthanides in bone disease treatment are summarized. The influence of lanthanide compounds with different ligands on the bone remodeling cycle and their potential application in the treatment and prevention of bone diseases is presented. According to the knowledge gained so far numerous applications of lanthanides cause that these elements and their compounds especially the lanthanide-based nanomaterials were tested in bone disorders therapy: radiation therapies, drug delivery systems, biosensing, bioimaging, as well as in implants, and tissue engineering. Revealing was also the structural studies which indicated why Ln-doped Hydroxyapatite was an excellent treatment for orthopedic injuries.
(C) 2019 Elsevier B.V.

Coordination Chemistry Reviews, 388(1), 248-267 (2019)

DOI: 10.1016/j.ccr.2019.03.003   (Pobrane:  2020-12-30)


307.

Wiesner M., Roberts R.H., Lin J.F., Akinwande D., Hesjedal T., Duffy L.B., Wang S.M., Song Y.X., Jenczyk J., Jurga S., Mróz B.

The effect of substrate and surface plasmons on symmetry breaking at the substrate interface of the topological insulator Bi2Te3 A pressing challenge in engineering devices with topological insulators (TIs) is that electron transport is dominated by the bulk conductance, and so dissipationless surface states account for only a small fraction of the conductance. Enhancing the surface-to-volume ratio is a common method to enhance the relative contribution of such states. In thin films with reduced thickness, the confinement results in symmetry-breaking and is critical for the experimental observation of topologically protected surface states. We employ micro-Raman and tip-enhanced Raman spectroscopy to examine three different mechanisms of symmetry breaking in Bi2Te3 TI thin films: surface plasmon generation, charge transfer, and application of a periodic strain potential. These mechanisms are facilitated by semiconducting and insulating substrates that modify the electronic and mechanical conditions at the sample surface and alter the long-range interactions between Bi2Te3 and the substrate. We confirm the symmetry breaking in Bi2Te3 via the emergence of the Raman-forbidden A(2u)(2) mode. Our results suggest that topological surface states can exist at the Bi2Te3/substrate interface, which is in a good agreement with previous theoretical results predicting the tunability of the vertical location of helical surface states in TI/ substrate heterostructures.

Scientific Reports, 9, 6147 (2019)

DOI: 10.1038/s41598-019-42598-9   (Pobrane:  2020-12-30)


306.

Kertmen A., Przysiecka Ł., Coy E., Popenda Ł., Andruszkiewicz R., Jurga S., Milewski S.

Emerging anticancer activity of candidal glucoseamine-6-phosphate synthase inhibitors upon nanoparticle-mediated delivery Numerous glutamine analogues have been reported as irreversible inhibitors of the glucosamine-6-phosphate (GlcN-6-P) synthase in pathogenic Candida albicans in the last 3.5 decades. Among the reported inhibitors, the most effective N-3-(4-methoxyfumaroy1)-L-2,3-diaminopropanoic acid (FMDP) has been extensively studied in order to develop its more active analogues. Several peptide-FMDP conjugates were tested to deliver FMDP to its subcellularly located GIcN-6-P synthase target. However, the rapid development of fungal resistance to FMDP-peptides required development of different therapeutic approaches to tackle antifungal resistance. In the current state of the global antifungal resistance, subcellular delivery of FMDP via free diffusion or endocytosis has become crucial. In this study, we report on in vitro nanomedical applications of FMDP and one of its ketoacid analogues, N-3-trans-4-oxo-4-phenyl-2-butenoyl-L-2,3-diaminopropanoic acid (BADP). FMDP and BADP covalently attached to polyethylene glycol-coated iron oxide/silica core-shell nanoparticles are tested against intrinsically multidrug-resistant C. albicans. Three different human cancer cell lines potentially overexpressing the GlcN-6-P synthase enzyme are tested to demonstrate the immediate inhibitory effects of nanoparticle conjugates against mammalian cells. It is shown that nanoparticle-mediated delivery transforms FMDP and BADP into strong anticancer agents by inhibiting the growth of the tested cancer cells, whereas their anti-Candidal activity is decreased. This study discusses the emerging inhibitory effect of the FMDP/BADP-nanoparticle conjugates based on their cellular internalization efficiency and biocompatibility.

Langmuir, 35(15), 5281-5293 (2019)

DOI: 10.1021/acs.langmuir.8b04250   (Pobrane:  2020-12-30)


305.

Kristinaityte K., Zalewski T., Kempka M., Sakirzanovas S., Baziulyte-Paulaviciene D., Jurga S., Rotomskis R., Valeviciene N.R.

Spin-lattice relaxation and diffusion processes in aqueous solutions of gadolinium-based upconverting nanoparticles at different magnetic fields We investigated the influence of gadolinium (Gd)-based upconverting nanoparticles (UCNPs) on water spin-lattice relaxation (T-1) and diffusion at different magnetic field strengths (0.4T and 9.4T). Our findings show that smaller NPs (12nm compared to 19nm) were more favourable for proton relaxivity. We also demonstrate that using simplified Solomon-Bloembergen-Morgan (SBM) model we can associate two measured diffusion coefficients with processes occurring near the surface of UCNPs and in bulk water. Using the relationship between relaxation and diffusion, we can estimate not only the total impact of NPs on relaxation of water molecules, but also the impact on relaxation of local water molecules, directly connected to paramagnetic Gd3+ ions in NPs. Different magnetic field strengths did not alter the spin-lattice relaxivity of NPs. This suggests that Gd-based UCNPs could be developed into high-performance multimodal magnetic resonance imaging contrast agents working over a broad range of imaging field strengths used in clinical routine.

Applied Magnetic Resonance, 50(4) SI, 553-561 (2019)

DOI: 10.1007/s00723-018-1105-z   (Pobrane:  2020-12-28)


304.

Jenczyk J., Woźniak-Budych M., Jancelewicz M., Jarek M., Jurga S.

Structural and dynamic study of block copolymer - Nanoparticles nanocomposites Nanocomposites based on block copolymer (BCP) and gold nanoparticles (NPs) filler were measured in terms of their structure and polymer chain molecular dynamics. NPs were functionalized in order to gain selective affinity to one specific type of BCP domain. BCP directed NPs assembly was monitored using atomic force microscopy. Thin nanocomposite films were fabricated via spin-coating technique, annealed and subsequently subjected to reactive ion etching in order to expose inorganic NPs location within the BCP matrix. Selective NPs incorporation was confirmed. Furthermore, interesting NPs distribution in quasi-2D crystallites was revealed. Spectroscopic methods (nuclear magnetic resonance and dielectric spectroscopy) enabled investigation of polymer chain reorientations and estimation of the impact of nano-filler on polymer dynamics. Nanocomposite crystallinity was assessed via thermal analysis and supported by spectroscopic techniques.

Polymer, 167, 130-137 (2019)

DOI: 10.1016/j.polymer.2019.01.080   (Pobrane:  2019-03-19)


303.

Grabowska M., Grześkowiak B.F., Szutkowski K., Wawrzyniak D., Głodowicz P., Barciszewski J., Jurga S., Rolle K., Mrówczyński R.

Nano-mediated delivery of double-stranded RNA for gene therapy of glioblastoma multiforme Glioblastoma multiforme (GBM) is the most common type of malignant gliomas, characterized by genetic instability, intratumoral histopathological variability and unpredictable clinical behavior. Disappointing results in the treatment of gliomas with surgery, radiation and chemotherapy have fueled a search for new therapeutic targets and treatment modalities. Here we report new approach towards RNA interference therapy of glioblastoma multiforme based on the magnetic nanoparticles delivery of the double-stranded RNA (dsRNA) with homological sequences to mRNA of tenascin-C (TN-C), named ATN-RNA. The obtained nanocomposite consisted of polyethyleneimine (PEI) coated magnetic nanoparticles conjugated to the dsRNA show high efficiency in ATN-RNA delivery, resulting not only in significant TN-C expression level suppressesion, but also impairing the tumor cells migration. Moreover, synthesized nanomaterials show high contrast properties in magnetic resonance imaging (MRI) and low cytotoxicity combining with lack of induction of interferon response. We believe that the present work is a successful combination of effective, functional, non-immunostimulatory dsRNA delivery system based on magnetic nanoparticles with high potential for further application in GBM therapy.

PloS ONE, 14(3), e0213852 (2019)

DOI: 10.1371/journal.pone.0213852   (Pobrane:  2020-12-28)


302.

Kertmen A., Barbe E., Szkoda M., Siuzdak K., Babacic V., Torruella P., Iatsunskyi I., Kotkowiak M., Rytel K., Estrade S., Peiro F., Jurga S., Li Yanguang, Coy E.

Photoelectrochemically active n-adsorbing ultrathin TiO2 layers for water-splitting applications prepared by pyrolysis of oleic acid on iron oxide nanoparticle surfaces under nitrogen environment Highly performing photocatalytic surfaces are nowadays highly desirable in energy fields, mainly due to their applicability as photo water-splitting electrodes. One of the current challenges in this field is the production of highly controllable and efficient photoactive surfaces on many substrates. Atomic layer deposition has allowed the deposition of photoactive TiO2 layers over wide range of materials and surfaces. However, nitrogen doping of the growing layers, a highly effective way of controlling the absorption edges of photoactive surfaced, is still a challenging task. Here, the preparation of hierarchical nanostructured surfaces based on Langmuir-Schaefer and atomic layer deposition is proposed. Ultrathin TiO2 layers that are photoelectrochemically active in water splitting are prepared by a relatively low-temperature catalytic decomposition of oleic acid capping layers of iron oxide nanoparticles and the posterior nitrogen adsorption. The results evidence that simple N-adsorption is sufficient to narrow the bandgap of TiO2 layers that is equal to bandgap narrowing (0.12 eV) observed for substitutionally N-doped materials. The photocatalytic activity tests of the prepared surfaces in water-splitting applications demonstrate approximate to 90% increase in the activity of the N-adsorbing TiO2 layers.

Advanced Materials Interfaces, 6(3), 1801286 (2019)

DOI: 10.1002/admi.201801286   (Pobrane:  2020-12-28)


301.

Mrówczyński R., d'Ischia M., Lee H., Jurga S.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

Erratum: 1st Symposium on polydopamine and NanoTech Poland 2018: Conference report (Vol. 3, 37, 2018) The authors regret that few mistakes were made in the original publication by Mrówczyński et al. [1]. Within the Acknowledgments section, the paragraph

..."The organizers would like to thank Ms. Dorat Flak, and Mrs. Lidia Szutkowska and Alicja Jorasz for their help in organizing the conference as well as for administrative support. We are grateful for all speakers and presenters for their valuable contributions to the conference, quality of their work, and their feedback in building a friendly atmosphere. The organizers also would like to thank the sponsors who provided support to the conference and brought valuable contribution."...

has been corrected to:

..."The authors would like to thank the entire organizing committee, in particular to Dr. Dorota Flak, Dr. Lidia Szutkowska, and Dr. Alicja Jorasz (NanoBioMedical Centre, Adam Mickiewicz University), for their invaluable commitment and effort. We are also grateful to Mr. Marek Nowak (Faculty of Physics, Adam Mickiewicz University), the author of the joint photo of the Symposium and NanoTech Poland participants."...

The authors would like to apologize for any inconvenience caused by these errors.

[1] Mrówczyński R., d’Ischia M., Lee H., Jurga S., 1st Symposium on Polydopamine and NanoTech Poland2018: Conference Report. Biomimetics, 2018,3, 37

Biomimetics, 4(1), 14 (2019)

DOI: 10.3390/biomimetics4010014   (Pobrane:  2020-12-27)


300.

Maziukiewicz D., Grześkowiak B.F., Coy E., Jurga S., Mrówczyński R.

NDs@PDA@ICG conjugates for photothermal therapy of glioblastoma multiforme The growing incidence of cancer is a problem for modern medicine, since the therapeutic efficacy of applied modalities is still not satisfactory in terms of patients’ survival rates, especially in the case of patients with brain tumors. The destructive influence of chemotherapy and radiotherapy on healthy cells reduces the chances of full recovery. With the development of nanotechnology, new ideas on cancer therapy, including brain tumors, have emerged. Photothermal therapy (PTT) is one of these. It utilizes nanoparticles (NPs) that can convert the light, preferably in the near-infrared (NIR) region, into heat. In this paper, we report the use of nanodiamonds (NDs) conjugated with biomimetic polydopamine (PDA) and indocyanine green (ICG) for glioblastoma cancer PTT therapy. The obtained materials were thoroughly analyzed in terms of their PTT effectiveness, as well as their physicochemical properties. The performed research demonstrated that NDs@PDA@ICG can be successfully applied in the photothermal therapy of glioblastoma for PTT and exhibited high photothermal conversion efficiency η above 40%, which is almost 10 times higher than in case of bare NDs. In regard to our results, our material was found to lead to a better therapeutic outcome and higher eradication of glioblastoma cells, as demonstrated in vitro.

Biomimetics, 4(1), 3 (2019)

DOI: 10.3390/biomimetics4010003   (Pobrane:  2021-01-27)


299.

Jurga S., Barciszewski J.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Systems Biology: Book Series: RNA Technologies, Ed. by Jurga S., Barciszewsk J., , V-VII (2019)


ISBN: 978-3-030-14791-4   (Pobrane:  2020-12-26)


298.

Pshyk A.V., Coy E., Kempiński M., Scheibe B., Jurga S.

Low-temperature growth of epitaxial Ti2AlC MAX phase thin films by low-rate layer-by-layer PVD Here we report on the structural and tribo-mechanical characterization of epitaxial single-crystalline Ti2AlC MAX phase thin films, grown by means of electron beam physical vapor deposition at relatively low temperature (700 degrees C). The growth of phase pure Ti2AlC at a relatively lower temperature when compared to other PVD methods was achieved utilizing a relatively low deposition rate and layer-by-layer deposition technique. The epitaxial growth is evidenced through the combination of XRD, HR-TEM and Raman spectroscopy measurements. The nanomechanical and micro-scale tribological properties of the Ti2AlC thin films were studied by means of nanoindentation and nanoscratch tests. IMPACT STATEMENT The growth temperature of phase pure single-crystalline Ti2AlC MAX phase thin films was reduced to 700 degrees C utilizing the low-rate layer-by-layer PVD technique.

Materials Research Letters, 7(6), 244-250 (2019)

DOI: 10.1080/21663831.2019.1594428   (Pobrane:  2020-12-28)


297.

Wieczorek E., Piskorz J., Popenda Ł., Jurga S., Mielcarek J., Goślinski T.

Magnesium porphyrazine with peripheral methyl (3,5-dibromophenylmethyl)amino groups - synthesis and optical properties Novel magnesium(II) porphyrazine with peripheral methyl(3,5-dibromophenylmethyl)amine groups was synthesized in a multi-step procedure starting from commercially available diaminomaleonitrile. All intermediates and the final macrocycle were characterized using UV-Vis, FT-IR, MS and various NMR techniques. The absorption and emission properties of the macrocycle were evaluated in N, N-dimethylformamide, dimethyl sulfoxide, and dichloromethane. The potential photosensitizing activity was evaluated by assessing the ability of the macrocycle to generate singlet oxygen in dimethyl sulfoxide and N, N-dimethylformamide.

Heterocyclic Communications, 25(1), 1-7 (2019)

DOI: 10.1515/hc-2019-0001   (Pobrane:  2020-12-28)


296.

Jędrzak A., Grześkowiak B.F., Coy E., Wojnarowicz J., Szutkowski K., Jurga S., Jesionowski T., Mrówczyński R.

Dendrimer based theranostic nanostructures for combined chemo- and photothermal therapy of liver cancer cells in vitro Here we report the synthesis of multifunctional nanocarriers based on PAMAM dendrimers generation (G) 4.0, 5.0 and 6.0 fixed to polydopamine (PDA) coated magnetite nanoparticles (Fe3O4). Synthesized nanoplatforms were characterized by transmission electron microscopy (TEM), the electrokinetic (zeta) potential, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and magnetic resonance imaging (MRI). Further, we show as a proof of concept that nanocarriers functionalized with G 5.0 could be successfully applied in combined chemo- and photothermal therapy (CT-PTT) of the liver cancer cells. The cooperative effect of the modalities mentioned above led to higher mortality of cancer cells when compared to their individual performance. Moreover, the performed in vitro studies revealed that the application of dual therapy triggered the desired cell death mechanism-apoptosis. Furthermore, performed tests using Magnetic Resonance Imaging (MRI) showed that our materials have competitive contrast properties. Overall, the functionality of dendrimers has been extended by merging them with magnetic nanoparticles resulting in multifunctional hybrid nanostructures that are promising smart drug delivery system for cancer therapy.

Colloids and Surfaces B: Biointerfaces, 173, 698-708 (2019)

DOI: 10.1016/j.colsurfb.2018.10.045   (Pobrane:  2019-03-21)


295.

Mrówczyński R., d'Ischia M., Lee H., Jurga S.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

1st Symposium on polydopamine and NanoTech Poland 2018: Conference report The NanoTech Poland is an annual international conference with a strong scientific agenda focused on nanotechnology in energy, environment, and biomedicine. The Nanotech Poland 2018 was held at the NanoBioMedical Centre and Department of Physics at Adam Mickiewicz University in Poznan from June 6th to June 9th. The aim of NanoTech Poland 2018 was to bring together the scientific community's principal investigators, scientists, researchers, analysts, clinicians, policy makers, industry experts, and well-established and budding entrepreneurs to discuss the present and future perspectives in nanotechnology and nanoscience research and development. This year, the 1st Symposium on Polydopamine was held on June 6th. This forum was dedicated to the application of polydopamine and related catechol materials in a variety of research fields, both at the nano- and macroscale. The symposium gathered leading scientists from this important research field from top universities and institutions that have been involved in the research revolved around polydopamine. With over 200 national and international participants, NanoTech Poland 2018 and the 1st Symposium on Polydopamine provided a forum to present and discuss the latest scientific news from the field of nanotechnology with a strong interdisciplinary aspect and bioinspired materials.

Biomimetics, 3(4), 37 (2018)

DOI: 10.3390/biomimetics3040037   (Pobrane:  2020-12-27)


294.

Flak D., Przysiecka Ł., Nowaczyk G., Scheibe B., Kościnski M., Jesionowski T., Jurga S.

GQDs-MSNs nanocomposite nanoparticles for simultaneous intracellular drug delivery and fluorescent imaging Although number of stimuli-responsive drug delivery systems based on mesoporous silica nanoparticles (MSNs) have been developed, the simultaneous real-time monitoring of carrier in order to guarantee proper drug targeting still remains as a challenge. GQDs-MSNs nanocomposite nanoparticles composed of graphene quantum dots (GQDs) and MSNs are proposed as efficient doxorubicin delivery and fluorescent imaging agent, allowing to monitor intracellular localization of a carrier and drug diffusion route from the carrier.Graphene quantum dots (average diameter 3.650.81nm) as a fluorescent agent were chemically immobilized onto mesoporous silica nanoparticles (average diameter 44.087.18nm) and loaded with doxorubicin. The structure, morphology, chemical composition, and optical properties as well as drug release behavior of doxorubicin (DOX)-loaded GQDs-MSNs were investigated. Then, the in vitro cytotoxicity, cellular uptake, and intracellular localization studies were carried out. Prepared GQDs-MSNs form stable suspensions exhibiting excitation-dependent photoluminescence (PL) behavior. These nanocomposite nanoparticles can be easily DOX-loaded and show pH- and temperature-dependent release behavior. Cytotoxicity studies proved that GQDs-MSNs nanocomposite nanoparticles are nontoxic; however, when loaded with drug, they enable the therapeutic activity of DOX via its active delivery and release. GQDs-MSNs owing to their fluorescent properties and efficient in vitro cellular internalization via caveolae/lipid raft-dependent endocytosis show a high potential for the optical imaging, including the simultaneous real-time optical tracking of the loaded drug during its delivery and release.

Journal of Nanoparticle Research, 20(11), 306 (2018)

DOI: 10.1007/s11051-018-4416-y   (Pobrane:  2020-12-27)


293.

Paprzycka M., Scheibe B., Jurga S.

Fish collagen - molecular structure after thermal treatment Modern medicine widely uses exogenous collagen as a good material for tissue regeneration, also as a natural substrate for cell attachment and proliferation, used to create dressings and to support the treatment of burn and diabetic wounds, or finally as a source of amino acids in the form of a dietary supplement. Collagen is a safe material that has high biocompatibility and biodegradability as well as good cell adhesion. Due to the possibility of transferring Creutzfeld-Jacobs disease (Bovine Spongiform Encephalopathy) from animals to the human body, interest in collagen from fish is currently increasing. The collagen we examined was derived from the skin of the silver carp fish (Hypophtalmichthys molitrix) and was obtained by the method of hydration in an aqueous lactic acid solution. The topography of the test sample was performed with the AFM method, showing its fibrillar structure with dimensions equivalent to those given in iterature. Raman spectroscopy was used to study fish collagen using a Renishaw Ramanscope with a helium-neon laser at a wavelength of 633 nm. Analysis of Raman spectra allowed to determine the content of amino acids in collagen, as well as glycine, praline and hydroxyproline. It also showed the native nature of the material at 20 degrees C. The partial renaturation of the secondary structure of this material heated to about 85 degrees C and cooled was also proved. Raman spectroscopy has been presented as an effective method for testing biopolymers.

Fibres & Textiles in Eastern Europe, 26(6), 51-56 (2018)

DOI: 10.5604/01.3001.0012.5170   (Pobrane:  2020-12-27)


292.

Kravchenko Y.O., Coy L.E., Peplińska B., Iatsunskyi I., Zaleski K., Kempiński M., Beresnev V.M., Konarski P., Jurga S., Pogrebnjak A.D.

Nano-multilayered coatings of (TiAlSiY)N/MeN (Me=Mo, Cr and Zr): Influence of composition of the alternating layer on their structural and mechanical properties Multilayered design showed itself to advantage for improvement of functional nitride coatings, which are widely required in various industry applications. This article reports on deposition and detailed characterization series of combined nano-multilayered coatings based on (TiAISiY)N with changes in components of alternating binary layers. Vacuum-arc deposited (TiAlSiY)N/MoN, (TiAlSiY)N/CrN and (TiAlSiY)N/ZrN coatings were analyzed by means of various experimental techniques such as SEM with EDS, XRD and GIXRD, SIMS, XPS and Raman spectroscopy. Microstructure of (TiAlSiY)N/MoN coating was characterized by creation of fine-grained fcc-AITiN phase of (200) plane with congruent growth of gamma-Mo2N (200) due to high isostruturality of lattices of alternating layers. The formation of fcc-AIYTiN phase of (111) plane and fcc-TiCrN phase of (200) plane were observed in multilayered (TiAlSiY)N/CrN coating and referred to the loss of clear interfaces and the formation of transition layers due to the diffusion of Ti atoms. Nano-multilayered (TiAlSiY)N/ZrN system showed the formation of stoichiometric fcc compounds of TiN with (200) plane and ZrN with (111) plane, respectively. The evaluation of mechanical properties as nanohardness, reduced elastic modulus, elastic strain prior to failure, and resistance to plastic deformation measurements was performed. The presented results showed important information about the physical and mechanical properties of new nano-multilayered systems for their subsequent application, as well as improvement of existing achievements.
(C) 2018 Elsevier B.V. All rights reserved. (C) 2018 Elsevier B.V. All rights reserved.

Journal of Alloys and Compounds, 767, 483-495 (2018)

DOI: 10.1016/j.jallcom.2018.07.090   (Pobrane:  2020-12-27)


291.

Bagdasaryan A.A., Pshyk A.V., Coy L.E., Kempiński M., Pogrebnjak A.D., Beresnev V.M., Jurga S.

Structural and mechanical characterization of (TiZrNbHfTa)N/WN multilayered nitride coatings The (TiZrNbHfTa)N/WN multicomponent coatings were deposited by vacuum arc evaporation under different substrate bias (-90 and -280 V). X-ray photoelectron spectroscopy was used for analyzing of complex composition of investigated coatings by reflecting of atomic scale chemical interactions. The structural investigations showed the formation of a simple disordered solid solution in (TiZrNbHfTa)N layer, beta-W2N phase in WN layer with fcc crystal structure and highly disordered bcc (1 1 0) and (2 2 0) -oriented high-entropy alloy phases, regardless of the applied bias potential. It was shown that with increasing of substrate bias from -90 to -280 V, there is a slight decrease of hardness from 34 to 31 GPa and increase of Young's modulus from 325 to 337 GPa, which can be explained by annihilation of point defects and precipitation of relatively softer metallic phase.
(C) 2018 Elsevier B.V. All rights reserved.

Materials Letters, 229, 364-367 (2018)

DOI: 10.1016/j.matlet.2018.07.048   (Pobrane:  2020-12-27)


290.

Tillo A., Kryjewski M., Bendzińska-Berus W., Langer D., Rębiś T., Popenda Ł., Jurga S., Mielcarek J., Goślinski T., Tykarska E.

Tetrapyrazinoporphyrazine with eight peripheral adamantanylsulfanyl units - Synthesis and physicochemical study A novel, (1-adamantylsulfanyl)-octasubstituted tetrapyrazinoporphyrazine has been synthesized and analyzed for its key physicochemical properties. Also, two 1-adamantylsulfanyl-substituted pyrazine derivatives were compared, and their crystallographic structures as well as chemical reactivity were assessed and discussed. Porphyrazine macrocycle showed good fluorescence and singlet oxygen generation properties as well as photostability. In addition, studied adamantylsulfanyl porphyrazine, despite its hydrophobic nature, revealed good solubility in polar solvents. Electrochemical studies revealed that the macrocycle underwent oxidation by one one-electron process and reduction with two one-electron processes.

Synthetic Metals, 244, 66-72 (2018)

DOI: 10.1016/j.synthmet.2018.07.002   (Pobrane:  2020-12-27)


289.

Graniel O., Fedorenko V., Viter R., Iatsunskyi I., Nowaczyk G., Weber M., Zaleski K., Jurga S., Smyntyna V., Miele P, Ramanavicius A., Balme S., Bechelany M.

Optical properties of ZnO deposited by atomic layer deposition (ALD) on Si nanowires In this work, we report proof-of-concept results on the synthesis of Si core/ ZnO shell nanowires (SiNWs/ZnO) by combining nanosphere lithography (NSL), metal assisted chemical etching (MACE) and atomic layer deposition (ALD). The structural properties of the SiNWs/ZnO nanostructures prepared were investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies. The X-ray diffraction analysis revealed that all samples have a hexagonal wurtzite structure. The grain sizes are found to be in the range of 7-14 nm. The optical properties of the samples were investigated using reflectance and photoluminescence spectroscopy. The study of photoluminescence (PL) spectra of SiNWs/ZnO samples showed the domination of defect emission bands, pointing to deviations of the stoichiometry of the prepared 3D ZnO nanostructures. Reduction of the PL intensity of the SiNWs/ZnO with the increase of SiNWs etching time was observed, depicting an advanced light scattering with the increase of the nanowire length. These results open up new prospects for the design of electronic and sensing devices.

Materials Science and Engineering B - Advanced Functional Solid-State Materials, 236, 139-146 (2018)

DOI: 10.1016/j.mseb.2018.11.007   (Pobrane:  2020-12-27)


288.

Lewandowski M., Pabisiak T., Michalak N., Miłosz Z., Babacic V., Wang Y., Hermanowicz M., Palotas K., Jurga S., Kiejna A.

On the sructure of utrathin FeO flms on Ag(111) Ultrathin transition metal oxide films exhibit unique physical and chemical properties not observed for the corresponding bulk oxides. These properties, originating mainly from the limited thickness and the interaction with the support, make those films similar to other supported 2D materials with bulk counterparts, such as transition metal dichalcogenides. Ultrathin iron oxide (FeO) films, for example, were shown to exhibit unique electronic, catalytic and magnetic properties that depend on the type of the used support. Ag(111) has always been considered a promising substrate for FeO growth, as it has the same surface symmetry, only similar to 5% lattice mismatch, is considered to be weakly-interacting and relatively resistant to oxidation. The reports on the growth and structure of ultrathin FeO films on Ag(111) are scarce and often contradictory to each other. We attempted to shed more light on this system by growing the films using different preparation procedures and studying their structure using scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). We observed the formation of a previously unreported Moire superstructure with 45 angstrom periodicity, as well as other reconstructed and reconstruction-free surface species. The experimental results obtained by us and other groups indicate that the structure of FeO films on this particular support critically depends on the films' preparation conditions. We also performed density functional theory (DFT) calculations on the structure and properties of a conceptual reconstruction-free FeO film on Ag(111). The results indicate that such a film, if successfully grown, should exhibit tunable thickness-dependent properties, being substrate-influenced in the monolayer regime and free-standing-FeO-like when in the bilayer form.

Nanomaterials, 8(10, 828 (2018)

DOI: 10.3390/nano8100828   (Pobrane:  2020-12-27)


287.

Pshyk A.V., Kravchenko Y., Coy E., Kempiński M., Iatsunskyi I., Zaleski K., Pogrebnjak A.D., Jurga S.

Microstructure, phase composition and mechanical properties of novel nanocomposite (TiAlSiY)N and nano-scale (TiAlSiY)N/MoN multifunctional heterostructures This paper reports on the deposition and characterization of (TiAlSiY)N nanocomposite and (TiAlSiY)N/MoN nano-scale multilayer coatings obtained by means of arc-PVD method. The investigation of structural-phase composition and mechanical properties is carried out by means of scanning electron microscopy (SEM), equipped with energy dispersive spectrum (EDS), High resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The microstructure of the (TiAlSiY)N nanocomposite coating shows preferential (111) growth of fcc-(Ti, Al)N grains. Multilayers coating of (TiAlSiY)N/MoN with a bilayer period of 10 ran was synthesized, showing that the fcc-MoN layer grows coherently with the fcc-(Ti,AI)N, due to the template effect of the latter, which results in a local cube on cube fcc(Ti,A1)N parallel to fcc(MoN) epitaxial growth with (200) preferential orientation. The hardness, reduced elastic modulus, elastic strain prior to plastic deformation and resistance to plastic deformation of the nano composite (TiAlSiY)N coating are determined as 24.6 GPa, 243 GPa, similar to 0.09 and 0.29 GPa, respectively. The enhancement of the mechanical properties of the multilayer coating up to 38.37, 392.5 GPa, similar to 0.09 and 0.38 GPa is also observed.

Surface & Coatings Technology, 350, 376-390 (2018)

DOI: 10.1016/j.surfcoat.2018.07.010   (Pobrane:  2020-12-27)


286.

Ivashchenko O., Przysiecka Ł., Peplińska B., Jarek M., Coy E., Jurga S.

Gel with silver and ultrasmall iron oxide nanoparticles produced with Amanita muscaria extract: physicochemical characterization, microstructure analysis and anticancer properties Combination therapy remains one of the most promising and intensively developed direction incancer treatment. This study is aimed to combine and investigate the anticancer properties of silver nanoparticles (NPs) and Amanita muscaria mushroom in gel formulation. For this, hyaluronic acid was used as gel-forming agent, whereas Amanita muscaria extract was used as capping agent during silver and ultrasmall iron oxide (MAg) NPs synthesis. Amanita muscaria compounds formed NP's surface layer and contributed anticancer properties, whereas silver NPs contributed anticancer, fluorescence and photoactive properties to the gel. Physicochemical characterization included X-ray diffraction (XRD), microscopies (SEM, cryo-SEM, TEM, confocal fluorescence), spectrofluorometric method, thermogravimetric analysis (TGA), dynamic light scattering (DLS) techniques, energy dispersive (EDS), Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopies, zeta-potential and rheological measurements. Microstructure analysis of hyaluronic acid/MAg NPs gel was performed by cryo-SEM technique. We showed that hyaluronic acid is a perfect gel-forming agent from both biomedical and technological points of view. It is well-mixed with MAg NPs forming stable gel formulation; high homogeneity of hyaluronic acid/MAg NPs gel was shown by SEM EDS elemental mapping. Microstructure of the gel was found to be highly ordered and consisted of domains from perforated parallel tubular structures. This finding expanded our understanding of gels and broke the stereotype of gel structure as chaotic network of fibers. Cytotoxicity studies performed on 2D and 3D HeLa cell cultures pointed to a high potential of hyaluronic acid/MAg NPs gel for local treatment of cancer. Cell response was found to be significantly different for 2D and 3D cell cultures that was related to their different cytoarhitecture and gene expression. Thus, the results of the cellular spheroids viability showed that they were significantly more resistant to the cytotoxic action of MAg NPs and their gel formulation than 2D cell culture. Hyaluronic acid used as gelling agent in gel formulation was found to increase an effectiveness of active components (MAg NPs, Amanita muscaria extract) probably improving their transport inside HeLa spheroids.

Scientific Reports, 8, 13260 (2018)

DOI: 10.1038/s41598-018-31686-x   (Pobrane:  2020-12-27)


285.

Pogrebnjak A.D., Beresnev V.M., Bondar O.V., Postolnyi B.O., Zaleski K., Coy E., Jurga S., Lisovenko M.O., Konarski P., Rebouta L., Araujo J.P.

Superhard CrN/MoN coatings with multilayer architecture Main regularities of the formation of microstructure and properties of multilayer nanostructured CrN/MoN films with periodically changing architecture of layers were considered. Coatings were fabricated by vacuum-arc evaporation of the cathodes (Arc-PVD) in nitrogen atmosphere (p(N) was 0.4, 0.09 and 0.03 Pa). CrN and gamma-Mo2N nitride phases with fcc lattices and a small volume of metastable MoNx cubic phase were formed in the films at pN = 0.4 Pa. The decrease of p(N) to 0.09 Pa causes the formation of beta-Cr2N hexagonal phase. Preferential crystallographic orientation changes from [311] to [111] and [200] when bias voltage U-b is -20, -150 and -300 V respectively. The nanocrystallites size in coatings with bilayer thickness lambda = 44 nm decreases to 5.8 nm. The microdeformation grows from 0.4 to 2.3% when U-b changes to -20 V. Coatings show high hardness of 38-42 GPa and H/E = 0.107. In a couple with results of tribological tests, coatings demonstrate strong wear resistance, which makes them appropriate and promising for industrial applications as protective ones. The effect of deposition conditions (p(N), U-b, lambda) on composition, structure, hardness, toughness and wear resistance was studied to achieve superior mechanical and physical properties of coatings with long lifetime in harsh environment.
(C) 2018 Elsevier Ltd. All rights

Materials & Design, 153, 47-59 (2018)

DOI: 10.1016/j.matdes.2018.05.001   (Pobrane:  2020-12-27)


284.

Istsunskyi I., Baitimirova M., Coy E., Yate L., Viter R., Ramanavicius A., Jurga S., Bechelany M., Erts D.

Influence of ZnO/graphene nanolaminate periodicity on their structural and mechanical properties Structural, electronic and mechanical properties of ZnO/Graphene (ZnO/G) nanolaminates fabricated by low temperature atomic layer deposition (ALD) and chemical vapor deposition (CVD) were investigated. We performed scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), electron energy loss spectroscopy (EELS), Raman spectroscopy, X-Ray photoelectron spectroscopy (XPS) and nanoindentation to characterize the ZnO/G nanolaminates. The main structural and mechanical parameters of ZnO/G nanolaminates were calculated. The obtained results were analyzed and interpreted taking into account mechanical interaction and charge effects occurring at the G-ZnO interface. The influence of graphene sublayers number on the mechanical behavior of the ZnO/G nanolaminates was studied. By reducing the bilayer thickness, the mechanical parameters of the films can be tuned (Young's modulus 100-200 GPa, hardness 3-9 GPa). The softer response of the multilayers as compared to the single layers of ZnO and graphene was attributed to the structural changes in the ZnO layer and the interfaces. This study shows the mechanical behavior of ZnO/G nanolaminates and their influence on the development of novel electro-optical devices based on these structures.
(C) 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Journal of Materials Science & Technology, 34(9), 1487-1493 (2018)

DOI: 10.1016/j.jmst.2018.03.022   (Pobrane:  2020-12-26)


283.

Bagdasaryan A.A., Pshyk A.V., Coy L.E., Konarski P., Misnik M, Ivashchenko V.I., Kempiński M., Mediukh N.R., Pogrebnjak A.D., Beresnev V.M., Jurga S.

A new type of (TiZrNbTaHf)N/MoN nanocomposite coating: Microstructure and properties depending on energy of incident ions A novel (TiZrNbTaHf)N/MoN nanocomposite coatings, which consist of the nitride of the high-entropy alloy and the binary nitride, were synthesized by vacuum-arc deposition at various substrate biases. The elemental composition, chemical bonding state, phase structure, microstructure and mechanical properties of the coatings were studied by high-resolution experimental methods: SIMS, GDMS, XPS, XRD, HR-TEM and nano-indentation. It was found that the chemical state of the (TiZrNbTaHf)N/MoN coatings has a complex nature, which consist of a mixture of nitrides of constituting elements. It was also shown that the coatings are based on B1 NaCl-structured gamma-Mo2N-phase with a mixture of crystallographic orientations (111), (200), (220) and (311) together with the B1 NaCl-structured (TiZrNbTaHf)N solid-solution phase. First-principles calculations demonstrated that the metal sub-lattice of the (TiZrNbTaHf)N solid solution can be based on Ti1-xHfyTa1-x-y, Zr1-xHfyTa1-x-y, Zr0.25Ti0.25Ta0.5 ternary alloys, which have the lowest mixing energy. The HR-TEM results showed that the nanocomposite nitride coatings have nano-scale multilayer structure with modulation periods ranged from 20 nm to 25 nm. The maximum hardness of approximately 29 GPa demonstrated the coating deposited at a higher energy condition (-200 V) with the thinnest modulation period of bilayer of 20 nm (15 rim of (TiZrNbTaHf)N and 5 nm of Mo2N).

Composites: part B - Engineering, 146, 132-144 (2018)

DOI: 10.1016/j.compositesb.2018.04.015   (Pobrane:  2020-12-26)


282.

Pogrebnjak A.D., Ivashchenko V.I., Skrynskyy P.L., Bondar O.V., Konarski P., Zaleski K., Jurga S., Coy E.

Experimental and theoretical studies of the physicochemical and mechanical properties of multi-layered TiN/SiC films: Temperature effects on the nanocomposite structure Nanoscale multilayered TiN/SiC films are of great importance in many electronic and industrial fields. The careful control over the structure of the laminates, nanocrystalline or amorphous, is crucial for their further applicability and study. However, several limitations in their fabrication have revealed important gaps in the understanding of this system. Here, we study influence of temperature on the physico-chemical and functional properties of TiN/SiC multilayers. We will show the clear increment on hardness of the samples, while the nanocomposite structure of the layers is maintained with no increment in crystal size. We will investigate the interstitial effects and rearrangements, between the TIN/SiC phases and their role in the enhanced mechanical response. Our experiments will dearly show a change in the modulation period of the samples, pointing to interfacial reactions, diffusion of ions or crystallization of new phases. Full Investigations of the film properties were carried out using several methods of analysis: XRD, XPS, FTIR, HR-TEM and SIMS Additionally, results were combined with First Principles MD computations of TiN/SiC heterostructures.

Composites: part B - Engineering, 142, 85-94 (2018)

DOI: 10.1016/j.compositesb.2018.01.004   (Pobrane:  2020-12-26)


281.

Boś-Liedke A., Walawender M., Woźniak A., Flak D., Gapiński J., Jurga S., Kucińska M., Plewiski A., Murias M., Elewa M., Lampp L., Imming P., Tadyszak K.

EPR Oximetry Sensor-Developing a TAM Derivative for In Vivo Studies Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1 mM PBS, pH = 7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH = 7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250 mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.

Cell Biochemistry and Biophysics, 76(1-2) SI, 19-28 (2018)

DOI: 10.1007/s12013-017-0824-3   (Pobrane:  2020-12-26)


280.

Siwińska-Stefańska K., Kubiak A., Piasecki A., Gościanska J., Nowaczyk G., Jurga S., Jesionowski T.

TiO2-ZnO binary oxide systems: Comprehensive characterization and tests of photocatalytic activity A series of TiO2-ZnO binary oxide systems with various molar ratios of TiO2 and ZnO were prepared using a sol-gel method. The influence of the molar ratio and temperature of calcination on the particle sizes, morphology, crystalline structure, surface composition, porous structure parameters, and thermal stability of the final hybrids was investigated. Additionally, to confirm the presence of characteristic surface groups of the material, Fourier transform infrared spectroscopy was applied. It was found that the crystalline structure, porous structure parameters, and thermal stability were determined by the molar ratio of TiO2 to ZnO and the calcination process for the most part. A key element of the study was an evaluation of the photocatalytic activity of the TiO2-ZnO hybrids with respect to the decomposition of C.I. Basic Blue 9, C.I. Basic Red 1, and C.I. Basic Violet 10 dyes. It was found that the TiO2-ZnO material obtained with a molar ratio of TiO2:ZnO = 9: 1 and calcined at 600 degrees C demonstrates high photocatalytic activity in the degradation of the three organic dyes when compared with pristine TiO2. Moreover, an attempt was made to describe equilibrium aspects by applying the Langmuir-Hinsherlwood equation.

Materials, 11(5), 841 (2018)

DOI: 10.3390/ma11050841   (Pobrane:  2020-12-26)


279.

Wieczorek E., Młynarczyk D.T., Kucińska M., Długaszewska J., Piskorz J., Popenda Ł., Szczółko W., Jurga S., Murias M., Mielcarek J., Goślinski T.

Photophysical properties and photocytotoxicity of free and liposome-entrapped diazepinoporphyrazines on LNCaP cells under normoxic and hypoxic conditions 5,7-Diaryl-substituted symmetrical diazepinoporphyrazine and tribenzodiazepinoporphyrazine were synthesized and characterized using UV-Vis, MS MALDI, and various NMR techniques. The expected photosensitizing potentials of these porphyrazines were evaluated by measuring their abilities to generate singlet oxygen in organic solvents and by comparing them with that of the recently obtained dendrimeric G1-type diazepinoporhyrazine. Absorbance and fluorescence measurements were performed to study the aggregation properties of the novel macrocycles. The photocytotoxicity of tribenzodiazepinoporphyrazine towards LNCaP cells in its free form and after its incorporation into liposomes was examined using MTT assay under normoxic and hypoxic conditions. It is interesting that all tested liposome formulations maintained their phototoxic activity in hypoxia. Also, tribenzodiazepinoporphyrazine incorporated into liposomes revealed better photocytotoxic effect (IC50 values of 0.600 +/- 0.357 mu M and 0378 +/- 0.002 mu M) than its free form (IC50 values of 3.135 +/- 0.156 mu M). Following the in vitro experiments, the most promising liposomal formulation containing L-alpha-phosphatidyl-DL-glycerol for tribenzodiazepinoporphyrazine was found. Moreover, tribenzodiazepinoporphyrazine incorporated into liposomes containing 1,2-dioleoyl-3-trimethylammonium-propane (chloride salt) revealed moderate phototoxicity at 5 x 10(-5) mu M for antibacterial photodynamic therapy. It was established that an irradiation of planktonic bacterial strains significantly reduced CFU5 of Staphylococcus aureus ATCC 25923 in comparison to tribenzodiazepinoporphyrazine containing L-alpha-phosphatidyl-DL-glycerol liposomes.
(C) 2018 Elsevier Masson SAS. All rights reserved.

European Journal of Medicinal Chemistry, 150, 64-73 (2018)

DOI: 10.1016/j.ejmech.2018.02.064   (Pobrane:  2020-12-26)


278.

Ivashchenko O., Peplińska B., Gapiński J., Flak D., Jarek M., Załęski K., Nowaczyk G., Pietralik Z., Jurga S.

Silver and ultrasmall iron oxides nanoparticles in hydrocolloids: effect of magnetic field and temperature on self-organization Micro/nanostructures, which are assembled from various nanosized building blocks are of great scientific interests due to their combined features in the micro- and nanometer scale. This study for the first time demonstrates that ultrasmall superparamagnetic iron oxide nanoparticles can change the microstructure of their hydrocolloids under the action of external magnetic field. We aimed also at the establishment of the physiological temperature (39°C) influence on the self-organization of silver and ultrasmall iron oxides nanoparticles (NPs) in hydrocolloids. Consequences of such induced changes were further investigated in terms of their potential effect on the biological activity in vitro. Physicochemical characterization included X-ray diffraction (XRD), optical microscopies (SEM, cryo-SEM, TEM, fluorescence), dynamic light scattering (DLS) techniques, energy dispersive (EDS), Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopies, zeta-potential and magnetic measurements. The results showed that magnetic field affected the hydrocolloids microstructure uniformity, fluorescence properties and photodynamic activity. Likewise, increased temperature caused changes in NPs hydrodynamic size distribution and in hydrocolloids microstructure. Magnetic field significantly improved photodynamic activity that was attributed to enhanced generation of reactive oxygen species due to reorganization of the microstructure.

Scientific Reports, 8, 4041 (2018)

DOI: 10.1038/s41598-018-22426-2   (Pobrane:  2018-03-20)


277.

Skupin-Mrugalska P., Sobotta Ł., Warowicka A., Wereszczyńska B., Zalewski T., Gierlich P., Jarek M., Nowaczyk G., Kempka M., Gapiński J., Jurga S., Mielcarek J.

Theranostic liposomes as a bimodal carrier for magnetic resonance imaging contrast agent and photosensitizer The present study is focused on the development of liposomes bearing gadolinium chelate (GdLip) providing two functionalities for magnetic resonance imaging (MRI) and photodynamic therapy of cancer. A lipid derivative of gadolinium(III) diethylenetriamine pentaacetic acid salt (GdDTPA1) was inserted in the liposomal membrane and served as MRI contrast agent whereas a zinc phthalocyanine (ZnPc) was used as a model photosensitizer. In addition to conventional liposomes, pegylated lipids were used for the preparation of "stealth" liposomes. The characterization of different GdLip formulations involved evaluation of the liposomes size by nanoparticle tracking analysis, thermal phase behavior by differential scanning calorimetry and ZnPc-mediated singlet oxygen production. Furthermore, relaxivity measurements were performed as well as cytotoxicity and photodynamic activity against cancerous and normal cell lines was studied. Size and thermal behavior were only slightly influenced by GdLip composition, however it distinctly affected singlet oxygen production of ZnPc-loaded GdLip. The quantum yields of singlet oxygen generation by zinc phthalocyanine incorporated in GdLip containing cationic or/and pegylated lipids were smaller than those obtained for non-pegylated carriers with l-alpha-phosphatidylglycerol. In general, all formulations of GdLip, irrespectively of composition, were characterized by relaxivities higher than those of commercially used contrast agents (e.g. Magnevist). NMR study has shown that the incorporation of ZnPc into the formulations of GdLip increases the relaxation parameters r1 and r2, compared to the values for the non-loaded vesicles. GdDTPA1 did not influence the photodynamic activity of ZnPc against HeLa cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Journal of Inorganic Biochemistry, 180, 1-14 (2018)

DOI: 10.1016/j.jinorgbio.2017.11.025   (Pobrane:  2018-03-20)


276.

Mrówczyński R., Jędrzak A., Szutkowski K., Grześkowiak B., Coy E., Markiewicz R., Jesionowski T., Jurga S.

Cyclodextrin-based magnetic nanoparticles for cancer therapy Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-beta-cyclodextrin (SH-beta CD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro. Moreover, our material exhibits improved T-2 contrast properties, which have been verified using Carr-Purcell-Meiboom-Gill pulse sequence and MRI Spin-Echo imaging of the nanoparticles dispersed in the agarose gel phantoms. Therefore, the presented results cast new light on the preparation of polydopamine-based magnetic theranostic nanomaterials, as well as on the proper methodology for investigation of magnetic nanoparticles in high field MRI experiments. The prepared material is a robust theranostic nanoasystem with great potential in nanomedicine.

Nanomaterials, 8(3), Article Number: UNSP 170 (2018)

DOI: 10.3390/nano8030170   (Pobrane:  2020-10-23)


275.

Scheibe B., Mrówczyński R., Michalak N., Zaleski K., Matczak M., Kempiński M., Pietralik Z., Lewandowski M., Jurga S., Stobiecki F.

Anchoring Fe3O4 nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating Reduced graphene oxide-magnetite hybrid aerogels attract great interest thanks to their potential applications, e.g., as magnetic actuators. However, the tendency of magnetite particles to migrate within the matrix and, ultimately, escape from the aerogel structure, remains a technological challenge. In this article we show that coating magnetite particles with polydopamine anchors them on graphene oxide defects, immobilizing the particles in the matrix and, at the same time, improving the aerogel structure. Polydopamine coating does not affect the magnetic properties of magnetite particles, making the fabricated materials promising for industrial applications.

Beilstein Journal of Nanotechnology, 9, 591-601 (2018)

DOI: 10.3762/bjnano.9.55   (Pobrane:  2018-03-20)


274.

Rajewsky N., Maier V., Jurga S., Barciszewski J.

Systems Biology: Book Series: RNA Technologies Rajewsky N., Jurga S., Barciszewsk J., , V-VII (2018)

DOI: 10.1007/978-3-319-92967-5   (Pobrane:  2020-12-26)


273.

Jenczyk J., Woźniak-Budych M., Jarek M., Jurga S.

Structural and dynamical study of PDMS and PS based block copolymers Block copolymers represent an interesting class of materials, combining properties of individual components and capable of developing nanoscopic domain morphologies. Copolymers which comprise polystyrene and poly(dimethylsiloxane) attract special attention due to their effective segregation and the highly contrasting thermal properties of individual blocks. This work covers structural studies of copolymeric domain architecture and investigates the molecular dynamics observed in bulk PDMS, diblock PS-PDMS and triblock PS-PDMS-PS. Utilization of atomic force microscopy and NMR spin diffusion provide a thorough picture of phase separated systems. Dielectric spectroscopy reveals the dynamic heterogeneity of PDMS amorphous phase. Two distinct structural relaxations, namely α and αc, were observed and attributed correspondingly to PDMS mobile amorphous fraction and PDMS rigid amorphous fraction. Unexpectedly, the segmental reorientations observed in the case of copolymers were faster that that observed for bulk PDMS.

European Polymer Journal, 98, 384-393 (2018)

DOI: 10.1016/j.eurpolymj.2017.11.045   (Pobrane:  2018-03-20)


272.

Baranowska-Korczyc A., Kościnski M., Coy E.L., Grześkowiak B.F., Jasiurkowska-Delaporte M., Peplińska B., Jurga S.

ZnS coating for enhanced environmental stability and improved properties of ZnO thin films Low environmental stability of ZnO nanostructures in hydrophilic systems is a crucial factor limiting their practical applications. ZnO nanomaterials need surface passivation with different water-insoluble compounds. This study describes a one-step passivation process of polycrystalline ZnO films with ZnS as a facile method of ZnO surface coating. A simple sulfidation reaction was carried out in gas-phase H2S and it resulted in formation of a ZnS thin layer on the ZnO surface. The ZnS layer not only inhibited the ZnO dissolving process in water but additionally improved its mechanical and electrical properties. After the passivation process, ZnO/ZnS films remained stable in water for over seven days. The electrical conductivity of the ZnO films increased about 500-fold as a result of surface defect passivation and the removal of oxygen molecules which can trap free carriers. The nanohardness and Young's modulus of the samples increased about 64% and 14%, respectively after the ZnS coating formation. Nanowear tests performed using nanoindentation methods revealed reduced values of surface displacements for the ZnO/ZnS system. Moreover, both ZnO and ZnO/ZnS films showed antimicrobial properties against Escherichia coli.

RSC Advances, 8(43), 24411-24421 (2018)

DOI: 10.1039/c8ra02823k   (Pobrane:  2020-12-26)


271.

Pavlenko M., Siuzdak K., Coy L.E., Jancelewicz M., Jurga S., Iatsunskyi I.

Silicon/TiO2 core-shell nanopillar photoanodes for enhanced photoelectrochemical water oxidation Nanostructured Si/TiO2 core-shell nanopillar (NP) photoanodes were synthesized to overcome photodegradation stability of Si and to enhance the efficiency for photoelectrochemical water splitting. The core-shell structures were fabricated by atomic layer deposition of TiO2 onto Si nanopillars synthesized by metal-assisted chemical etching and nanosphere lithography. Scanning electron microscopy, transmission electron microscopy, Raman and reflectance spectroscopies were utilized to characterize fabricated photoanodes. The obtained Si/TiO2 core-shell NP arrays exhibit less than 6% of optical reflectance in UV and visible region, providing good optical absorption. Photoelectrochemical (PEC) water oxidation of fabricated photoanodes was studied. We showed that n-Si/n-TiO2 NP exhibited a larger photocurrent than p-Si/n-TiO2 due to a barrier at the heterojunction. Optimal morphological parameter of Si/TiO2 NP for enhanced PEC water splitting were found. We demonstrated its enhanced PEC performance with a photocurrent density of 1.5 mA/cm2 under simulated solar radiation with intensity of 100 mW/cm2. The relationship between the PEC performance and the electrolyte pH was also discussed. The design of the geometry of Si/TiO2 core-shell NP arrays offers a new approach for preparing stable and highly efficient photoanodes for PEC water splitting.

International Journal of Hydrogen Energy, 42(51), 30076-30085 (2017)

DOI: 10.1016/j.ijhydene.2017.10.033   (Pobrane:  2017-12-21)


270.

Woźniak-Budych M.J., Przysiecka Ł., Maciejewska B.M., Wieczorek D., Staszak K., Jarek M., Jesionowski T., Jurga S.

Facile synthesis of sulfobetaine-stabilized Cu2O nanoparticles and their biomedical potential A novel approach using a zwitterionic sulfobetaine-based surfactant for the synthesis of spherical copper oxide nanoparticles (Cu2O NPs) has been applied. For the first time, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate has been used as stabilizer to control the size and morphology of Cu2O NPs. Several techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and fluorescence spectroscopy, are used to investigate the size, structure, and optical properties of synthesized Cu2O nanocrystals. The results indicate that copper(I) oxide nanoparticles with size in the range of 2 to 45 nm and crystalline structure, exhibit intense yellow fluorescence (lambda(em) = 575 nm). Furthermore, the cytotoxicity studies show that sulfobetaine-stabilized copper oxide nanoparticles prompt inhibition of cancer cell proliferation in a concentration-dependent manner, however, the adverse effect on the normal cells has also been observed. The results indicate that the sulfobetaine-stabilized Cu2O, because of their unique properties, have a potential to be applied in medical fields, such as cancer therapy and bioimaging.

ACS Biomaterials Science & Engineering, 3(12), 3183-3194 (2017)

DOI: 10.1021/acsbiomaterials.7b00465   (Pobrane:  2018-03-20)


269.

Pogrebnjak A., Ivashchenko V., Bondar O., Beresnev V., Sobol O., Zaleski K., Jurga S., Coy E., Konarski P., Postolnyi B.

Multilayered vacuum-arc nanocomposite TiN/ZrN coatings before and after annealing: Structure, properties, first-principles calculations Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 degrees C. All deposited samples were highly polycrystalline with quite large 20-25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 degrees C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance.

Materials Characterization, 134, 55-63 (2017)

DOI: 10.1016/j.matchar.2017.10.016   (Pobrane:  2018-03-20)


268.

Gołąbiewska A., Lisowski W., Jarek M., Nowaczyk G., Michalska. M., Jurga S., Zaleska-Medyńska A.

The effect of metals content on the photocatalytic activity of TiO2 modified by Pt/Au bimetallic nanoparticles prepared by sol-gel method The TiO2 modified by monometallic (Au-TiO2, Pt-TiO2) and bimetallic (Pt/Au-TiO2) NPs have been synthesized by a simple sol-gel method. The optimal dosage of individual components in Pt/Au composition on photocatalytic activity has been systematically investigated. The obtained photocatalysts were thoroughly characterized by BET surface area measurements, UV vis diffuse-reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), scanning transmission microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity under visible light (lambda >420 nm and lambda >455 nm) has been estimated in phenol degradation reaction in an aqueous phase. The best photocatalytic activity has been observed for mono (0.5)Pt_TiO2 and bimetallic (0.5)Pt/(0.5)Au_TiO2 samples with an optimum platinum content. The Pt/Au_TiO2 radical formation mechanism was systematically investigated with the selected scavenger for the degradation process under vis light irradiation. The formation of O-2(center dot)- with (0.5)Pt/(0.5)Au_TiO2 was established from the high inhibition of phenol degradation. Based on the XPS analysis it was observed that the greater photoactivity of bimetallic sample (0.5)Pt/(0.5)Au_TiO2 could result from a relatively higher content of platinum compared to gold on the surface layer. It must be noted that only platinum takes a significant part in Pt/Au composites on the photoactivity. Furthermore, in this work we present a linear relationship between the crystal size of TiO2 and the reaction rate of Au-TiO2, Pt-TiO2 and Pt/Au-TiO2. © 2017 Elsevier B.V. All rights reserved.

Molecular Catalysis, 442, 154-163 (2017)

DOI: 10.1016/j.mcat.2017.09.004   (Pobrane:  2018-03-20)


267.

Ivashchenko O., Gapiński J., Peplińska B., Przysiecka Ł.,Zalewski T., Nowaczyk G., Jarek M., Marcinkowska-Gapińska A., Jurga S.

Self-organizing silver and ultrasmall iron oxide nanoparticles prepared with ginger rhizome extract: Characterization, biomedical potential and microstructure analysis of hydrocolloids Multimodal nanoparticles (NPs) that may be used for therapies and diagnostics is the most promising trend for efficient therapy. We demonstrate that nanocomposite based on self-organizing silver and ultrasmall magnetic iron oxide NPs (MAg) produced in one-step synthesis revealed unique combination of fluorescence, bactericidal, fungicidal properties and have a potential as magnetic resonance imaging (MRI) contrast agent. Using the green chemistry approach, ginger (Zingiber officinale) rhizome extract was applied as capping agent for MAg synthesis, providing also additional fluorescent properties of NPs and inducing hydrocolloids structuring. The MAg were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive microanalysis (EDS), fluorescence microscopy, cryo-SEM, dynamic light scattering (DLS) techniques, Fourier transforminfrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopies. MAg dispersions in water and some biological media are very stable which is important for biomedical application. The existence of microstructure inMAg hydrocolloids was proved. The hierarchical character and high ordering of this microstructure were discovered and its level-by-level building blocks were investigated. The microstructure was found to be responsible for fluorescence emittance of MAg hydrocolloids. The properties as well as potential application of the MAg hydrocolloids is yet to be discovered. © 2017 Elsevier Ltd. All rights reserved.

Materials & Design, 133, 307-324 (2017)

DOI: 10.1016/j.matdes.2017.08.001   (Pobrane:  2018-03-20)


266.

Woźniak A., Grześkowiak B.F., Babayevska N., Zalewski T., Drobna M., Woźniak-Budych M., Wiweger M., Słomski R., Jurga S.

ZnO@Gd2O3 core/shell nanoparticles for biomedical applications: Physicochemical, in vitro and in vivo characterization The chemical composition of nanoparticles (NPs) may be so designed as to provide measurability for numerous imaging techniques in order to achieve synergistic advantages. Innovative and unique structure of the core/shell ZnO@Gd2O3 NPs possesses luminescent and magnetic properties, and is expected that they will become a new generation of contrast agents for Magnetic Resonance Imaging (MRI) and nanocarriers for theranostics. Thus, by surface biofunctionalization, it is possible to indicate particular nanoparticle compositions which provide efficient imaging, targeted drug delivery, and biocompatibility. Novel ZnO@Gd2O3 NPs were synthesized and biofunctionalized by folic acid (FA) and doxorubicin (Doxo) to provide target and anticancer functions. Physicochemical analyses of the nanoparticles were performed. The biological study included a cytotoxicity in vitro, cellular distribution evaluation, as well as toxicity analyses, performed for the first time, on the in vivo zebrafish (Danio rerio) model. Nanoparticles were found to be effective double-function biomarkers (MRI T-2 contrast agents, fluorescent imaging). The biological study showed that ZnO@Gd2O3 and ZnO@Gd2O3@OA-polySi@FA NPs are biocompatible in a particular concentration ranges. Conjugation with folic acid and/or doxorubicin resulted in effective drug delivery targeting. The in vivo results described the toxicology profile toward the zebrafish embryo/larvae, including new data concerning the survival, hatching ratio, and developmental malformations. © 2017 Elsevier B.V. All rights reserved.

Materials Science & Engineering C - Materials for Biological Applications, 80, 603-615 (2017)

DOI: 10.1016/j.msec.2017.07.009   (Pobrane:  2018-03-20)


265.

Kertmen A., Torruella P., Coy E., Yate L., Nowaczyk G., Gapiński J., Vogt C., Toprak M., Estrade S., Peiro F., Milewski S., Jurga S., Andruszkiewicz R.

Acetate-induced disassembly of spherical iron oxide nanoparticle clusters into monodispersed core-shell structures upon nanoemulsion fusion It has been long known that the physical encapsulation of oleic acid-capped iron oxide nanoparticles (OA-IONPs) with the cetyltrimethylammonium (CTA(+)) surfactant induces the formation of spherical iron oxide nanoparticle clusters (IONPCs). However, the behavior and functional properties of IONPCs in chemical reactions have been largely neglected and are still not well-understood. Herein, we report an unconventional ligand-exchange function of IONPCs activated when dispersed in an ethyl acetate/acetate buffer system. The ligand exchange can successfully transform hydrophobic OA-IONP building blocks of IONPCs into highly hydrophilic, acetate-capped iron oxide nanoparticles (Ac-IONPs). More importantly, we demonstrate that the addition of silica precursors (tetraethyl orthosilicate and 3-aminopropyltriethoxysilane) to the acetate/oleate ligand-exchange reaction of the IONPs induces the disassembly of the IONPCs into monodispersed iron oxide-acetate-silica core-shell-shell (IONPs@acetate@SiO2) nanoparticles. Our observations evidence that the formation of IONPs@acetate@SiO2 nanoparticles is initiated by a unique micellar fusion mechanism between the Pickering-type emulsions of IONPCs and nanoemulsions of silica precursors formed under ethyl acetate buffered conditions. A dynamic rearrangement of the CTA(+)-oleate bilayer on the IONPC surfaces is proposed to be responsible for the templating process of the silica shells around the individual IONPs. In comparison to previously reported methods in the literature, our work provides a much more detailed experimental evidence of the silica-coating mechanism in a nanoemulsion system. Overall, ethyl acetate is proven to be a very efficient agent for an effortless preparation of monodispersed IONPs@acetate@SiO2 and hydrophilic Ac-IONPs from IONPCs.

Langmuir, 33(39), 10351-10365 (2017)

DOI: 10.1021/acs.langmuir.7b02743   (Pobrane:  2018-03-20)


264.

Modrzejewska-Sikorska A., Konował E., Klapiszewski Ł., Nowaczyk G., Jurga S., Jesionowski T., Milczarek G.

Lignosulfonate-stabilized selenium nanoparticles and their deposition on spherical silica We report a novel room-temperature synthesis of selenium nanoparticles, which for the first time uses lignosulfonate as a stabilizer. Various lignosulfonates obtained both from hardwood and softwood were tested. Selenium oxide was used as the precursor of zero-valent selenium. Three different reducers were tested sodium borohydride, hydrazine and ascorbic acid and the latter proved most effective in terms of the particle size and stability of the final colloid. The lignosulfonate-stabilized selenium nanoparticles had a negative zeta potential, dependent on pH, which for some lignosulfonates reached -50 mV, indicating the excellent stability of the colloid. When spherical silica particles were introduced to the synthesis mixture, selenium nanoparticles were deposited on their surface. Additionally, starlike structures consisting of sharp selenium needles with silica cores were observed. After drying, the selenium-functionalized silica had a grey metallic hue. The method reported here is simple and cost-effective, and can be used for the preparation of large quantities of selenium colloids or the surface modification of other materials with selenium.

International Journal of Biological Macromolecules, 103, 403-408 (2017)

DOI: 10.1016/j.ijbiomac.2017.05.083   (Pobrane:  2018-03-19)


263.

Stodolny M., Zagrodnik R., Nowaczyk G., Jurga S.

Size-controlled synthesis of anatase nanobrush structures with higher crystal density Titanium dioxide was synthesized in multistep process applying of AAO (Anode Aluminum Oxide) as a template. The TiO2 nanowires were obtained by deposition of titanium precursors inside the pores of AAO membranes (non-hydrolytic sol-gel technique), calcined at 875 K with subsequent removal of alumina matrix by leaching it with phosphoric acid. During the AAO synthesis, it was proved that the electrical work can serve as the unified factor influencing the amount of formed AAO. The diameters of obtained titania nanowires were consequence of used AAO membranes. The higher density of titania elementary cell was observed for all synthesized nanostructures. It was confirmed by XRD and SAED measurements. The TiO2 nanowires attached vertically to polymer disc (50 mm diameter) were used in photocatalytic decomposition of methyl orange. All nanomaterials showed ten times higher photo catalytic activity than P-25. High photoactivity of obtained material is related to external area of vertically aligned titania nanowires. © 2017 Elsevier Ltd. All rights reserved.

Materials Research Bulletin, 94, 335-341 (2017)

DOI: 10.1016/j.materresbull.2017.06.010   (Pobrane:  2018-03-20)


262.

Pogrebnjak A., Rogoz V., Ivashchenko V., Bondar O., Shevchenko V., Jurga S., Coy E.

Nanocomposite Nb-Al-N coatings: Experimental and theoretical principles of phase transformations Phase transformations of Al doped NbN nanocomposite coatings are studied in detail focusing on their microstructural evolution and phase composition. Several techniques such as XRD, SEM, HR-TEM, Nanoindentation and molecular dynamics simulation are employed in order to understand the phase evolution of the Nb-Al-N system. The nanocomposite structures were formed in the coatings, the roughness of the coatings decreased with increasing the Al concentration due to decreasing grain size. First-principles investigation of Nb-Al-N solid solutions was carried out to interpret film properties. It was found, that for small Al fractions, the solid solutions will form in agreement with our experimental results. The spinodal decomposition of Nb-Al-N solid solutions is supposed to be responsible for the formation of the nanocomosite structure observed in the deposited Nb-Al-N films.

Journal of Alloys and Compounds, 718, 260-269 (2017)

DOI: 10.1016/j.jallcom.2017.05.136   (Pobrane:  2018-03-19)


261.

Coy E., Graczyk P., Yate L., Zaleski K., Gapiński J.,Kuświk P., Mielcarek S., Stobiecki F., Mróz B., Ferrater C., Jurga S.

Second harmonic generation response in thermally reconstructed multiferroic beta '-Gd-2(MoO4)(3) thin films Gd-2(MoO4)(3) (GMO) is a well-studied multiferroic material that exhibits full ferroelectric and ferroelastic behavior at room temperature. However, its difficult stabilization in thin films has prevented the study and exploitation of its multiferroic properties in different architectures. Here, we report on the study of GMO thin films deposited on Si(001) substrates by Pulsed Laser Deposition (PLD). The physicochemical properties of the films are discussed and studied. Results obtained by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution transmission microscopy and second harmonic generation show that the orthorhombic (beta'-GMO) multiferroic phase can be stabilized and homogenized by post deposition thermal reconstruction. Finally, the reconstruction process takes place via a complex surface mechanism with a clear leaf-like behavior

Scientific Reports, 7, 11800 (2017)

DOI: 10.1038/s41598-017-12370-y   (Pobrane:  2020-10-23)


260.

Dobies M., Makrocka-Rydzyk M., Jenczyk J., Jarek M., Spontak R.J., Jurga S.

Molecular dynamics study of polystyrene-b-poly(ethylene oxide) asymmetric diblock copolymer systems Two polystyrene-b-poly(ethylene oxide) (PS-b-PEO) diblock copolymers differing in molecular mass (49 and 78 kDa), but possessing the same PEO cylindrical morphology, are examined to elucidate their molecular dynamics. Of particular interest here is the molecular motion of the PEO blocks involved in the rigid amorphous fraction (RAF). Analysis of complementary thermal calorimetry and X-ray scattering data confirm the presence of a microphase-separated morphology, as well as semi-crystalline structure, in each copolymer. Molecular motion within the copolymer systems is monitored by dielectric and nuclear magnetic resonance spectroscopies. Results reported herein reveal the existence of two local, Arrhenius-type processes attributed to non-cooperative local motion of PEO segments involved in fully amorphous and rigid amorphous PEO microphases. In both systems, two structural relaxations governed by glass transition phenomena are identified and assigned to cooperative segmental motion in the fully amorphous phase (the αc process) and the RAF (the αc process). We measure the temperature dependence of the dynamics associated with all the processes mentioned above and propose that these local processes are associated with corresponding cooperative segmental motion in both copolymer systems. In marked contrast to the thermal activation of the αc process as discerned in both copolymers, the αc process appears to be a sensitive probe of the copolymer nanostructure. That is, the copolymer with shorter PEO blocks exhibits more highly restricted cooperative dynamics of PEO segments in the RAF, which can be explained in terms of the greater constraint imposed by the glassy PS matrix on the PEO blocks comprising smaller cylindrical microdomains.

Langmuir, 33(36), 8856-8868 (2017)

DOI: 10.1021/acs.langmuir.7b02017   (Pobrane:  2020-10-23)


259.

Warowicka A., Maciejewska B.M., Litowczenko J., Kościński M., Baranowska-Korczyc A., Jasiurkowska-Delaporte M., Kozioł K., Jurga S.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

Corrigendum to “MWCNT based matrices as a platform for adhesion and growth of cells” [Compos. Sci. Technol. 136 (2016) 29-38] The authors regret that the author Anna Baranowka-Korczyc is actually Anna Baranowska-Korczyc.

The authors would like to apologise for any inconvenience caused.

Composites Science and Technology, 149, 305-305 (2017)

DOI: 10.1016/j.compscitech.2017.05.023   (Pobrane:  2018-03-20)


258.

Boś-Liedke A. Walawender M., Woźniak A., Flak D., Gapiński J., Jurga S., Kucińska M., Plewiński A., Murias M., Elewa M., Lampp L., Imming P., Tadyszak K.

EPR oximetry sensor-developing a TAM derivative for in vivo studies Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1mM PBS, pH=7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH=7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250 mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.

Cell Biochemistry and Biophysics, , 1-10 (2017)

DOI: 10.1007/s12013-017-0824-3   (Pobrane:  2020-10-23)


257.

Flak D., Yate L., Nowaczyk G., Jurga S.

Hybrid ZnPc@TiO2 nanostructures for targeted photodynamic therapy, bioimaging and doxorubicin delivery In this study ZnPc@TiO2 hybrid nanostructures, both nanoparticles and nanotubes, as potential photosensitizers for the photodynamic therapy, fluorescent bioimaging agents, as well as anti-cancer drug nanocarriers, were prepared via zinc phthalocyanine (ZnPc) deposition on TiO2. In order to provide the selectivity of prepared hybrid nanostructures towards cancer cells they were modified with folic acid molecules (FA). The efficient attachment of both ZnPc and FA molecules was confirmed with dynamic light scattering (DLS), zeta potential measurements and X-ray photoelectron spectroscopy (XPS). It was presented that ZnPc and FA attachment has a strong effect on fluorescence emission properties of TiO2 nanostructures, which can be further used for their simultaneous visualization upon cellular uptake. ZnPc@TiO2 and FA/ZnPc@TiO2 hybrid nanotubes were then employed as doxorubicin nanocarriers. It was demonstrated that doxorubicin can be easily loaded on these hybrid nanostructures via an electrostatic interaction and then released. In vitro cytotoxicity and photo-cytotoxic activity studies showed that prepared hybrid nanostructures were selectively targeting to cancer cells. Doxorubicin loaded hybrid nanostructures were significantly more cytotoxic than un-loaded ones and their cytotoxic effect was even more severe upon irradiation. The cellular uptake of prepared hybrid nanostructures and their localization in cells was monitored in vitro in 2D cell culture and tumor-like 3D multicellular culture environment with fluorescent confocal microscopy. These hybrid nanostructures preferentially penetrated into human cervical cancer cells (HeLa) than into normal fibroblasts (MSU-1.1) and were mainly localized within the cell cytoplasm. HeLa cells spheroids were also efficiently labelled by prepared hybrid nanostructures. Fluorescent imaging of Hela cells treated with doxorubicin loaded hybrid nanostructures showed that doxorubicin was effectively delivered into cells, released and evenly distributed in the cytoplasm. In conclusion, prepared hybrid nanostructures exhibit high potential as selective bioimaging agents next to their photodynamic activity and drug delivery ability.

Materials Science & Engineering C: Materials for Biological Applications, 78, 1072-1085 (2017)

DOI: 10.1016/j.msec.2017.04.107   (Pobrane:  2018-03-19)


256.

Kempiński M., Florczak P., Jurga S., Sliwińska-Bartkowiak M., Kempiński W.

The impact of adsorption on the localization of spins in graphene oxide and reduced graphene oxide, observed with electron paramagnetic resonance We report the observations of electronic properties of graphene oxide and reduced graphene oxide, performed with electron paramagnetic resonance technique in a broad temperature range. Both materials were examined in pure form and saturated with air, helium, and heavy water molecules. We show that spin localization strongly depends on the type and amount of molecules adsorbed at the graphene layer edges (and possible in-plane defects). Physical and chemical states of edges play crucial role in electrical transport within graphene-based materials, with hopping as the leading mechanism of charge carrier transport. Presented results are a good basis to understand the electronic properties of other carbon structures made of graphene-like building blocks. Most active carbons show some degree of functionalization and are known of having good adsorptive properties; thus, controlling both phenomena is important for many applications. Sample treatment with temperature, vacuum, and various adsorbents allowed for the observation of a possible metalinsulator transition and sorption pumping effects. The influence of adsorption on the localization phenomena in graphene would be very important if to consider the graphene-based material as possible candidates for the future spintronics that works in ambient conditions. Published by AIP Publishing

Applied Physics Letters, 111(8), 084102 (2017)

DOI: 10.1063/1.4996914   (Pobrane:  2018-03-19)


255.

Mazierski P., Nadolna J., Nowaczyk G., Lisowski W., Winiarski M.J., Klimczuk T., Kobylański M.P., Jurga S., Zaleska-Medyńska A.

Highly visible-light-photoactive heterojunction based on TiO2 nanotubes decorated by Pt nanoparticles and Bi2S3 quantum dots A heterojunction with excellent visible light response and stability based on titanium dioxide nanotubes (TiO2 NTs), bismuth sulfide quantum dots (Bi2S3 QDs), and, platinum nanoparticles (Pt NPs) is proposed. Both Pt NPs (3.0 ± 0.2 nm) and Bi2S3 QDs (3.50 ± 0.20 nm) are well distributed on the (i) top parts, (ii) inner walls, and (iii) outer walls of the TiO2 NTs. Visible-light-induced photoreaction was initialized by excitation of narrow band gap Bi2S3 QDs, followed by electron injection to the conduction band of TiO2, while Pt NPs acted as electron traps, enhacing 02(-) generation. Phenol in the aqueous phase and toluene in the gas phase were efficiently degraded over Bi2S3 Pt NTs, even for wavelengths longer than 455 and 465 nm, respectively, while no degradation of model compounds was observed over pristine TiO2 NTs under the same irradiation conditions. Photocatalytic tests of phenol degradation in the presence of scavengers revealed that superoxide radicals were responsible for the visible-light degradation of organic compounds in the aqueous phase.

Journal of Physical Chemistry C, 121(32), 17215-17225 (2017)

DOI: 10.1021/acs.jpcc.7b03895   (Pobrane:  2018-03-19)


254.

Iatsunskyi I., Vasylenko A., Viter R., Kempiński M., Nowaczyk G., Jurga S., Bechelany M.

Tailoring of the electronic properties of ZnO-polyacrylonitrile nanofibers: Experiment and theory We report the study of ZnO-polyacrylonitrile (ZnO-PAN) nanofibers fabricated by the combination of electrospinning and atomic layer deposition. The latter technique enables us to control the size of the surface of ZnO 1D nanostructures and hence its effectiveness for energy and biosensor applications. We observe the tendency of ZnO to form nanograins with increase of the layer thickness, and investigate the influence of the grain size on the electronic properties of the nanofibers. It is demonstrated that the ZnO work function (Phi) is strongly affected by surface band bending in the ZnO layer. The observed change of Phi in ZnO layers results from the curvature of the grain surface as well as the presence of the hydroxyl and oxygen groups, adsorbed on ZnO surface and is in a good agreement with theoretical prediction.

Applied Surface Science, 411, 494-501 (2017)

DOI: 10.1016/j.apsusc.2017.03.111


253.

Kempiński M., Łoś S., Florczak P., Kempiński W., Jurga S.

EPR and impedance measurements of graphene oxide and reduced graphene oxide We report the observations of electron paramagnetic resonance and impedance measurements of graphene oxide and reduced graphene oxide performed in the wide temperature range in order to get insight into the electronic properties of graphene-based materials and the role of oxygen functionalities in the charge carrier transport phenomena. In such systems the strong spin localization, hopping charge carrier transport as well as the formation of adsorption layers are observed, all the phenomena changing significantly after the heavily oxidized graphene is reduced.

Acta Physica Polonica A, 132(1), 81-85 (2017)

DOI: 10.12693/APhysPolA.132.81   (Pobrane:  2018-03-19)


252.

Kempiński M., Jenczyk J., Jurga S., Śliwińska-Bartkowiak M.

Wetting of nanostructurized sapphire and gold surfaces We present the results of preliminary experiments regarding research on the contact angle measurements of various liquids on solid surfaces with different morphology. The aim was to get insight into the dependence of wetting phenomena on the nanoscale surface roughness. Flat and nanostructurized surfaces of gold and sapphire were used in the experiments. Four liquids - bromobenzene, water, mercury, and gallium - covering a broad range of surface tension values were used to check how varying roughness influences wetting in the systems with different adhesion/cohesion ratio. Structurization was anisotropic, which resulted in the very interesting behaviour of the examined liquids on the selected surfaces. Significant change of the wetting properties was observed as well as a strong dependence on the surface morphology.

Acta Physica Polonica A, 132(1), 185-188 (2017)

DOI: 10.12693/APhysPolA.132.185   (Pobrane:  2017-11-04)


251.

Tadyszak K., Kertmen A., Coy E., Andruszkiewicz R., Milewski S., Kardava I., Scheibe B., Jurga S., Chybczyńska K.

Spectroscopic and magnetic studies of highly dispersible superparamagnetic silica coated magnetite nanoparticles Superparamagnetic behavior in aqueously well dispersible magnetite core-shell Fe3O4@SiO2 nanoparticles is presented. The magnetic properties of core-shell nanoparticles were measured with use of the DC, AC magnetometry and EPR spectroscopy. Particles where characterized by HR-TEM and Raman spectroscopy, showing a crystalline magnetic core of 11.5 ± 0.12 nm and an amorphous silica shell of 22 ± 1.5 nm in thickness. The DC, AC magnetic measurements confirmed the superparamagnetic nature of nanoparticles, additionally the EPR studies performed at much higher frequency than DC, AC magnetometry (9 GHz) have confirmed the paramagnetic nature of the nanoparticles. Our results show the excellent magnetic behavior of the particles with a clear magnetite structure, which are desirable properties for environmental remediation and biomedical applications.

Journal of Magnetism and Magnetic Materials, 433, 254-261 (2017)

DOI: 10.1016/j.jmmm.2017.03.025


250.

Wencka M., Apih T., Korosec R.C., Jenczyk J., Jarek M., Szutkowski K., Jurga S., Dolinsek J.

Molecular dynamics of 1-ethyl-3-methylimidazolium triflate ionic liquid studied by H-1 and F-19 nuclear magnetic resonances The molecular dynamics of an ionic liquid (IL) composed of a 1-ethyl-3-methylimidazolium cation and a triflate (trifluoromethanesulfonate) anion, abbreviated as [Emim][TfO], were studied by NMR spectroscopy. By measuring the temperature-dependent high-field H-1 and F-19 spin-lattice relaxation (SLR) rates, the frequency-dependent H-1 and F-19 SLR dispersion curves using fast-field-cycling relaxometry, and the temperature-dependent H-1 and F-19 diffusion constants, and by utilizing the fact that the primary NMR-active nucleus on the Emim cation is 1H, whereas on the TfO anion it is F-19, the cationic and anionic dynamics were studied separately. A single theoretical relaxation model successfully reproduced all the experimental data of both types of resonant nuclei by fitting all the data simultaneously with the same set of fit parameters. Upon cooling, [Emim][TfO] exhibited a supercooled liquid phase between T-SL = 256 K and the crystallization temperature T-Cr approximate to 227-222 K, as confirmed by differential scanning calorimetry (DSC) experiments. Theoretical analysis revealed that within the liquid and the supercooled liquid states of [Emim][TfO], the H-1 and F-19 relaxation rates are affected by both the rotational and translational diffusional processes with no discontinuous change at TSL. While the rotational diffusion is well described as an Arrhenius thermally activated process, the translational diffusion undergoes strong freezing dynamics that are well described by the Vogel-Fulcher model assuming a freezing temperature of T-0 = 157 K. The existence of the supercooled liquid region in the [Emim][TfO] IL should be taken into account when using this IL for a specific application.

Physical Chemistry Chemical Physics, 19(23), 15368-15376 (2017)

DOI: 10.1039/c7cp01045a


249.

Krysztofik A., Głowiński H., Kuświk P., Ziętek S., Coy L.E., Rychły J.N., Jurga S., Stobiecki T.W., Dubowik J.

Characterization of spin wave propagation in (111) YIG thin films with large anisotropy We report on long-range spin wave (SW) propagation in nanometer-thick yttrium iron garnet (YIG) film with an ultralow Gilbert damping. The knowledge of a wavenumber value vertical bar(k) over right arrow vertical bar is essential for designing SW devices. Although determining the wavenumber vertical bar(k) over right arrow vertical bar in experiments like Brillouin light scattering spectroscopy is straightforward, quantifying the wavenumber in all-electrical experiments has not been widely commented upon so far. We analyze magnetostatic spin wave (SW) propagation in YIG films in order to determine the SW wavenumber vertical bar(k) over right arrow vertical bar excited by the coplanar waveguide. We show that it is crucial to consider the influence of magnetic anisotropy fields present in YIG thin films for precise determination of SW wavenumber. With the proposed methods we find that experimentally derived values of vertical bar(k) over right arrow vertical bar are in perfect agreement with that obtained from electromagnetic simulation only if anisotropy fields are included.

Journal of Physics D: Applied Physics, 50(23), 235004 (2017)

DOI: 10.1088/1361-6463/aa6df0


248.

Woźniak A., Malankowska A., Nowaczyk G., Grześkowiak B.F., Tuśnio K., Słomski R., Zaleska-Medyńska A., Jurga S.

Size and shape-dependent cytotoxicity profile of gold nanoparticles for biomedical applications Metallic nanoparticles, in particular gold nanoparticles (AuNPs), offer a wide spectrum of applications in biomedicine. A crucial issue is their cytotoxicity, which depends greatly on various factors, including morphology of nanoparticles. Because metallic nanoparticles have an effect on cell membrane integrity, their shape and size may affect the viability of cells, due to their different geometries as well as physical and chemical interactions with cell membranes. Variations in the size and shape of gold nanoparticles may indicate particular nanoparticle morphologies that provide strong cytotoxicity effects. Synthesis of different sized and shaped bare AuNPs was performed with spherical (similar to 10 nm), nanoflowers (similar to 370 nm), nanorods (similar to 41 nm), nanoprisms (similar to 160 nm) and nanostars (similar to 240 nm) morphologies. These nanostructures were characterized and interacting with cancer (HeLa) and normal (HEK293T) cell lines and cell viability tests were performed by WST-1 tests and fluorescent live/ dead cell imaging experiments. It was shown that various shapes and sizes of gold nanostructures may affect the viability of the cells. Gold nanospheres and nanorods proved to be more toxic than star, flower and prism gold nanostructures. This may be attributed to their small size and aggregation process. This is the first report concerning a comparison of cytotoxic profile in vitro with a wide spectrum of bare AuNPs morphology. The findings show their possible use in biomedical applications.

Journal of Materials Science-Materials in Medicine, 28(6), 92 (2017)

DOI: 10.1007/s10856-017-5902-y


247.

Dobies M., Iżykowska J., Wilkowska M., Woźniak-Braszak A., Szutkowski K., Skrzypczak A., Jurga S., Kozak M.

Dispersion of water proton spin-lattice relaxation rates in aqueous solutions of multiwall carbon nanotubes (MWCNTs) stabilized via alkyloxymethylimidazolium surfactants Carbon nanotubes and a number of other carbon nanomaterials have a tendency to aggregate, which often resulted in difficulties of dispersion of these nanomaterials in aqueous solutions. The ability of dicationic (gemini) surfactants to disperse multiwall carbon nanotubes in water and the dynamic processes taking place at the water-MWCTs interface are studied. Stable dispersions of multi-wall carbon nanotubes with selected gemini surfactants (1,1’-(1,6-hexanediyl)bis(3-alkyloxymethylimidazolium) dichlorides) were prepared and characterized by nuclear magnetic relaxation dispersion (NMRD), NMR diffusometry, scanning and transmission electron microscopy, and Fourier transform infrared spectroscopy. The addition of multiwall carbon nanotubes to aqueous solutions of studied gemini surfactants leads to significant paramagnetic enhancement of the spin-lattice relaxation processes, which gets more pronounced with increasing concentration of well-dispersed MWNTs in water. The dominant role of outer sphere (OS) relaxation mechanism in total observed R1, governed by two-dimensional diffusion of water on the carbon nanotube surface in the vicinity of paramagnetic centers incorporated in the MWCNTs side-walls (mainly of iron origin), was assumed to explain NMRD data. The NMR diffusion experiments confirm the existence of restricted water diffusion in the studied supernatants. The NMR diffusion results are consistent with the FTIR and NMR proton spin-lattice relaxation dispersion in which the more effective R1 dispersion noticed for the sample with IMIC6C12 was ascribed to the better accessibility of water molecules to the surface of the MWCNTs.

The Journal of Physical Chemistry, 121(21), 11839-11850 (2017)

DOI: 10.1021/acs.jpcc.7b01801


246.

Jenczyk J., Woźniak-Budych, M., Jarek M., Grzeszkowiak M., Nowaczyk G., Jurga S.

Nanoparticle string formation on self-assembled copolymer films Nanoparticles (NP) string formations on self-assembled copolymeric substrates has been observed. These "thread of beads" like structures develop via simple colloidal droplet evaporation during meniscus rim withdrawal on polystyrene-block-poly(ethylene oxide) (PS-PEO) copolymer surfaces. It is shown that the process is triggered by the presence of the substrate impurities, which lead to NP aggregate formations serving as string initiation sites. The growth mechanism of these linear structures seems to be capillarity-driven. Moreover, there is an exceptional alignment coupling between NP strips and the block copolymer (BC) domains observed. BC directed NP assembly stems from a gold nanocrystal surface functionalization, which introduces selective affinity for one particular type of BC domain. The presented results reveal a potential fabrication method of NP wires characterized by remarkably low width and thickness comparable with the size of the individual constituent NP.

Applied Surface Science, 406, 235-244 (2017)

DOI: 10.1016/j.apsusc.2017.02.143


245.

Falkowski M., Rębiś T., Piskorz J., Popenda Ł., Jurga S., Mielcarek J., Milczarek G., Gośliński T.

Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode - effect of nitro peripheral groups on electrochemical properties We report on the synthesis, MS, UV-vis, NMR, HPLC and electrochemical characterization of magnesium sulfanyl porphyrazine with 2-[2-(4-nitrophenoxy) ethoxy] ethylsulfanyl substituents in the periphery. The electrochemical properties of novel macrocycle were studied by cyclic voltammetry and differential pulse voltammetry in non-aqueous electrolyte. The experimental data indicated the occurrence of clearly defined four redox couples corresponded to one-electron reactions of the pi-conjugated porphyrazine ring and substituents in the periphery. Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on a glassy carbon electrode allowed for the evaluation of the effect of nitro peripheral groups on the electrochemical properties. The electrochemical behavior of immobilized nitro porphyrazine was consistent with the reduction mechanism for the various arylnitro compounds in aqueous media, with two processes characteristic of the redox transitions of the arylnitro group to the corresponding arylhydroxylamine and/or arylhydroxylamine-arylnitroso groups.

Journal of Porphyrins and Phthalocyanines, 21(46) SI, 295-301 (2017)

DOI: 10.1142/S1088424617500134   (Pobrane:  2018-03-19)


244.

Babayevska N., Florczak P., Woźniak-Budych M., Jarek M., Nowaczyk G., Zalewski T., Jurga S.

Functionalized multimodal ZnO@Gd2O3 nanosystems to use as perspective contrast agent for MRI The main aim of this research was the synthesis of the multimodal hybrid ZnO@Gd2O3 nanostructures as prospective contrast agent for Magnetic Resonance Imaging (MRI) for bio-medical applications. The nanoparticles surface was functionalized by organosilicon compounds (OSC) then, by folic acid (FA) as targeting agent and doxorubicin (Dox) as chemotherapeutic agent. Doxorubicin and folic acid were attached to the nanoparticles surface by amino groups as well as due to attractive physical interactions. The morphology and crystallography of the nanostructures were studied by HRTEM and SAXS techniques. After ZnO nanoparticles surface modification by Gd3+ and annealing at 900 degrees C, ZnO@Gd2O3 nanostructures are polydispersed with size 30-100 nm. NMR (Nuclear Magnetic Resonance) studies of ZnO@Gd2O3 were performed on fractionated particles with size up to 50 nm. Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, zeta-potential measurements and energy dispersive X-ray analysis (EDX) showed that functional groups have been effectively bonded onto the nanoparticles surface. The high adsorption capacity of folic acid (up to 20%) and doxorubicin (up to 40%) on nanoparticles was reached upon 15 min of adsorption process in a temperature-dependent manner.

Applied Surface Science, 404, 129-137 (2017)

DOI: 10.1016/j.apsusc.2017.01.274


243.

Fantechi E., Roca A.G., Sepulveda B., Torruella P., Estrade S., Peiro F., Coy E., Jurga S., Bastus N.G., Nogues, J., Puntes V.

Seeded growth synthesis of Au-Fe3O4 heterostructured nanocrystals: Rational design and mechanistic insights Multifunctional hybrid nanoparticles comprising two or more entities with different functional properties are gaining ample significance in industry and research. Due to its combination of properties, a particularly appealing example is Au-Fe3O4 composite nanoparticles. Here we present an indepth study of the synthesis of Au-Fe3O4 heterostructured nanocrystals (HNCs) by thermal decomposition of iron precursors in the presence of preformed 10 nm Au seeds. The role of diverse reaction parameters on the HNCs formation was investigated using two different precursors: iron pentacarbonyl (Fe(CO)(5)) and iron acetylacetonate (Fe(acac)(3)). The reaction conditions promoting the heterogeneous nucleation of Fe3O4 onto Au seeds were found to significantly differ depending on the precursor chosen, where Fe(acac)(3) is considerably more sensitive to the variation of the parameters than Fe(CO)(5) and more subject to homogeneous nucleation processes with the consequent formation of isolated iron oxide nanocrystals (NCs). The role of the surfactants was also crucial in the formation of well-defined and monodisperse HNCs by regulating the access to the Au surface. Similarly, the variations of the [Fe]/[Au] ratio, temperature, and employed solvent were found to act on the mean size and the morphology of the obtained products. Importantly, while the optical properties are rather sensitive to the final morphology, the magnetic ones are rather similar for the different types of obtained HNCs. The surface functionalization of dimer-like HNCs with silica allows their dispersion in aqueous media, opening the path to their use in biomedical applications.

Chemistry of Materials, 29(9), 4022-4035 (2017)

DOI: 10.1021/acs.chemmater.7b00608


242.

Tillo A., Młynarczyk D.T., Popenda Ł., Wicher B., Kryjewski M., Szczołko W., Jurga S., Mielcarek J., Gdaniec M., Gośliński T., Tykarska E.

Synthesis and singlet oxygen generation of pyrazinoporphyrazines containing dendrimeric aryl substituents Pyrazinoporphyrazines and tribenzopyrazinoporphyrazines were synthesized and studied towards their potential applications in photodynamic therapy. The macrocycles were obtained via Linstead macrocyclization with good yields. The expansion of the porphyrazine periphery with hyperbranched aryl substituents was beneficial in terms of purification and isolation of compounds, effectively hampering their aggregation tendency in different concentrations. The obtained macrocycles were assessed for their singlet oxygen generation quantum yields and revealed far better efficacies for tribenzopyrazinoporphyrazines than pyrazinoporphyrazines. A comparison of the crystal packing of two 2,3-dicyanopyrazine derivatives revealed that the recurring motif of the supramolecular architecture is a dimer formed by pi-pi stacking interactions between aromatic pyrazine and phenyl rings of the inversion center related molecules.

Colloids and Surfaces B: Biointerfaces, 41(9), 3586-3594 (2017)

DOI: 10.1039/c6nj03886g   (Pobrane:  2021-01-20)


241.

Dunst K.J., Scheibe B., Nowaczyk G., Jurga S., Jasiński P.

Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties A graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. In order to obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at constant potential of -0.85 V. The GO, RGO and PEDOT-RGO composites were characterized by scanning and high resolution transmission electron microscopies with electron energy loss spectroscopy, Fourier-transform infrared and Raman spectroscopies. In this work the effect of GO electrochemical reduction process was discussed. The effects of the humidity and sensing response of GO, RGO and PEDOT-RGO to different gases were investigated. It was found out the PEDOT-RGO response to NO2 was much higher than to the other analyzed gases. The influence of the operating temperature on the gas sensing response was compared. The role of the polymer and RGO in PEDOT-RGO composite has been indicated. The results are discussed in light of recent literature on graphene sensors.

Measurement Science and Technology, 28(5), 054005 (2017)

DOI: 10.1088/1361-6501/aa57e7   (Pobrane:  2020-10-23)


240.

Ivashchenko O., Woźniak A., Coy E., Peplińska B., Gapiński J., Jurga S.

Release and cytotoxicity studies of magnetite/Ag/antibiotic nanoparticles: An interdependent relationship Though the cytotoxic properties of magnetite nanoparticles (NPs) are rather well investigated and known to be dose dependent and rather low, surface functionalization can drastically change their properties. To determine whether the cytotoxicity of magnetite/Ag/antibiotic NPs may be associated, among other things, with iron, silver and antibiotic release, this study investigates the release profiles and cytotoxicity of magnetite/Ag/rifampicin and magnetite/Ag/doxycycline NPs compares it similar profiles from magnetite, magnetite/Ag NPs and antibiotics. It was established that the studied NPs released not only water-soluble substances, such as antibiotics, but also poorly-soluble ones, such as iron and silver. The deposition of silver on the magnetite surface promotes the release of iron by the formation of a galvanic couple. Antibiotic adsorbed on the magnetite/Ag surface plays a dual role in the galvanic corrosion processes: as a corrosion inhibitor for iron oxides and as a corrosion promoter for silver. Magnetite/Ag/rifampicin and magnetite/Ag/doxycycline. NPs were found to have greater cytotoxicity towards the HEK293T cell line than magnetite NPs. These results were attributed to the combined toxic action of the released iron, silver ions and antibiotics. Intensive and simultaneous release of the NP components caused cell stress and suppressed their growth.

Colloids and Surfaces B: Biointerfaces, 152, 85-94 (2017)

DOI: 10.1016/j.colsurfb.2017.01.009   (Pobrane:  2021-01-20)


239.

Woźniak-Budych M.J., Przysiecka Ł., Langer K., Peplińska B., Jarek M., Wiesner M., Nowaczyk G., Jurga S.

Green synthesis of rifampicin-loaded copper nanoparticles with enhanced antimicrobial activity The antimicrobial properties of copper and rifampicin-loaded copper nanoparticles were investigated using four strains: Staphylococcus aureus, Escherichia coli, Bacillus pumilis and Pseudomonas fluorescens. Spherical-shaped copper nanoparticles were synthesized via green reduction method from the peppermint extract. It was found that adsorption of rifampicin on the copper nanosurface enhances its biological activity and prevents the development of resistance. The interactions between rifampicin-copper nanoparticles and bacteria cells were monitored using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). It was proven that loaded with rifampicin copper nanoparticles were able to damage the S. aureus cell membrane and facilitate the bacteria biofilm matrix disintegration. Moreover, the DNA decomposition of S. aureus treated with copper and rifampicin-copper nanoparticles was confirmed by agarose gel electrophoresis. The results obtained indicate that adsorption of rifampicin on the copper nanoparticles surface might provide the reduction of antibiotic dosage and prevent its adverse side effects.

Journal of Materials Science. Materials in Medicine, 28(3), 42 (2017)

DOI: 10.1007/s10856-017-5857-z


238.

Falkowski M., Rębiś T., Kryjewski M., Popenda Ł., Lijewski S., Jurga S., Mielcarek J., Milczarek G., Goślińki T.

An enhanced electrochemical nanohybrid sensing platform consisting of reduced graphene oxide and sulfanyl metalloporphyrazines for sensitive determination of hydrogen peroxide and L-cysteine Sulfanyl porphyrazine with isophthaloxyalkyl substituents was metallated with copper(II), cobalt(II) and iron(II) metal ions. New macrocycles were characterized using MS, UV-Vis and NMR spectroscopy. Compounds were carefully purified by column chromatography and their purity was analyzed by HPLC. According to the voltammetric analysis data, the copper(II), cobalt(II) and iron(II) sulfanyl porphyrazine complexes exhibited good electrochemical reversibility. Well-defined metal ion centered redox processes were observed for cobalt(II) and iron(II) derivatives. These compounds were considered as the electrocatalytically active complexes and immobilized by pi-pi stacking forces within the matrix of electrochemically reduced graphene oxide. The porphyrazine-graphene hybrids revealed stronger electrocatalytic performance than their separately analyzed counterparts. The electrocatalytic properties of the investigated materials were attributed to the contributions from both the reduced graphene oxide conducting matrix, and the faradaic reactions provided by porphyrazine metal complex immobilized on the electrodes. In the presence of 1 mM of L-cysteine or hydrogen peroxide, the electrocatalytic oxidation coupled with higher catalytic current with reduced overpotential, was observed at the glassy carbon/ reduced graphene oxide modified electrode. It was found that the glassy carbon/reduced graphene oxide/porphyrazine electrodes can assay L-cysteine in the linear range between 1.0 and 660 mu M (LOD of 0.79 mu M) and hydrogen peroxide in the linear range between 4.5 and 460 mu M (LOD of 4.0 mu M). The formation of the metalled porphyrazine/reduced graphene oxide hybrid is a valuable strategy in obtaining synergetic effects between the redox active macrocyclic complex and a highly conducting carbon support which has potential value for the development of advanced electrodes for electrocatalytic applications

Dyes and Pigments, 138, 190-203 (2017)

DOI: 10.1016/j.dyepig.2016.11.045


237.

Wieczorek E., Piskorz J., Popenda Ł., Jurga S., Mielcarek J., Gośliński T.

First example of a diazepinoporphyrazine with dendrimeric substituents The synthesis and physicochemical properties of a novel diazepinoporphyrazine possessing G1-dendrimeric substituents are presented. Initially, diaminomaleonitrile was condensed with 1,3-bis-(4hydroxyphenyl)-1,3-propanedione to give a novel 1,4-diazepine-2,3-dicarbonitrile derivative which was subjected to an alkylation reaction with 3,5-bis(benzyloxy)benzylbromide furnishing a 1,4-diazepine-2,3-dicarbonitrile derivative with bulky substituents. Subsequent macrocyclization led to the desired diazepinoporphyrazine with conjugated, hyperbranched Gl-dendrimeric substituents, which was characterized by MS MALDI and NMR. The potential photosensitizing activity of the novel porphyrazine was evaluated by measuring its ability to generate singlet oxygen. This measurement was performed with and without addition of the anti-aggregation agent tetramethylamonium fluoride to determine the role of the monomeric form in singlet oxygen generation.

Tetrahedron Letters, 58(8), 758-761 (2017)

DOI: 10.1016/j.tetlet.2017.01.027


236.

Moliński A., Zaręba J., Iżykowska J., Skupin M., Andrzejewska W., Jurga S., Kozak M.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

C-60 fullerenes as contrast agents - structural, spectroscopic and nano-toxicity studies Recently, C60 fullerenes have been proposed as contrast agents for MRI method [1]. Especially promising for in vitro and in vivo NMR imaging are their complexes with gadolinum (containing Gd3+ ions entrapped inside the fullerene cage) known also as gadofullerenes [2]. The general problem of carbon nanomaterials is their toxicity towards living cells [3]. The aim of our study is to devise fullerene-based suspensions characterized with low toxicity, which could later be developed into metallofullerene contrast agents. We want to achieve that goal using C60 fullerenes, pluronics to lower the toxicity and phosphatidylcholine derivatives (DMPC or DPPC) to enhance biocompatibility of fullerenes and to stimulate the cellular absorption. In this work we would like to present results of toxicity studies of C60 fullerene systems pluronic modified C60 fullerene systems towards HeLa cells, along with results of structural analyses by AFM and SEM microscopies, FTIR and SAXS. This study was supported by Ministry of Science and Higher Education (Poland), within the project, Najlepsi z najlepszych!”

Biophysical Journal, 112(3) S1, 593A (2017)

DOI: 10.1016/j.bpj.2016.11.3191   (Pobrane:  2020-11-05)


235.

Skupin M., Iżykowska J., Andrzejewska W., Dobies M., Jurga S., Kozak M.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

Interactions of carbon nanotubes stabilized by selected gemini surfactants with model biomembranes Thanks to the extraordinary mechanical strength and high electrical conductivity multiwalled carbon nanotubes are currently used in electronics, medicine (as biomedical sensors, transporters or drugs) as well as in the production of lightweight and durable construction. The aim of this study was to determine the possibility to use different cationic gemini surfactants with different spacer lengths or alkyl chain lengths in more efficient systems for dispersing nanostructures in aqueous solutions. The most important advantages of these systems are their non-immunogenic, biocompatible properties and generally low toxicity . Therefore nanotubes, surrounded by surfactants, have the potential to interact with biological membranes. For this purpose we studied the influence of dispersed CN solution on the phase behavior of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) - a phospholipid most often present in membranes of nerve cells. The microstructure of the stable suspension of carbon nanotubes was investigated using high-resolution Transmission Electron Microscopy and Atomic Force Microscopy. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) were used to analyze the influence of surfactants studied, used for CN dispersion, on the phase behavior of DMPC bilayers. A series of measurements of toxicity of these systems were performed in HeLa and fibroblast cell cultures. This work was supported by the Ministry of Science and Higher Education, within the project “Najlepsi z najlepszych!” dec.

Biophysical Journal, 112(3) S1, 77A (2017)

DOI: 10.1016/j.bpj.2016.11.460   (Pobrane:  2020-11-05)


234.

Iżykowska J., Skupin M., Andrzejewska W., Dobies M., Jurga S., Kozak M.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

Carbon nanostructures of different spatial geometry: their dispersion and influence on model biological systems The discovery of carbon nanostructures (CN) in the last century has revolutionized science, opening new research opportunities in biophysics, material sciences, biomedicine and pharmacology [1]. Unfortunately, carbon nanomaterials show a strong tendency towards aggregation and poor stability in solutions. Such properties, especially the suspension stability, are critical for bio-applications of carbon nanostructures [2]. Surface functionalization of nanocarbons improves the dispersing properties in water solutions but it may also influence their physicochemical properties [3]. For preparation of biocompatible CN samples we used novel dicationic surfactant (gemini) with imidazole head groups. Nanocarbon suspensions were investigated in the context of their anticancer activity, as well as their application as multimodal contrast/drug delivery agents. Different spatial geometries of CN may be of key importance for designing of the efficient anti-cancer system. Such systems were subjected to the cytotoxicity tests on HeLa cell cultures. The structural properties of selected, the most effective systems based on CN suspensions were characterized by the use of SEM, AFM and NMR methods. This study was supported by the Ministry of Science and Higher Education (Poland), within the project “Najlepsi z najlepszych!”

Biophysical Journal, 112(3) S1, 156A (2017)

DOI: 10.1016/j.bpj.2016.11.857   (Pobrane:  2020-11-05)


233.

Zaręba J., Iżykowska J., Skupin M., Moliński A., Dobies M., Jurga S., Kozak M.

Abstrakt lub materiały konferencyjne, albo abstrakt publikacji
z dodatkowymi numerami DOI

The influence of surfactant structure and geometry on nanotoxicity and dispersion of carbon nanotubes Graphene, nanotubes and fullerenes, also known as carbon nanomaterials (CN), because of the their unique properties have potential applications not only in preparation of new composite materials or in electronics, but they can be also components of drug delivery systems. However, the applications of CN in life sciences or biomedicine require stable dispersions of these materials in water. The hydrophobic nature of CN causes serious problems with their separation in water solutions. Our study is aimed to find a way of dispersing such CN systems in water, by the use of non-covalent surface modification via different surfactants. In this work we focused on the use of trimeric, dimeric and monomeric surfactants fornon-covalent surface modification of selected carbon nanotubes. The toxicity of these systems (aqueous solutions of CN with surfactants and surfactants solutions) towards selected cell cultures (e. g. HeLa cells) was also tested. The surfactants studied can interact with carbon nanotubes in a number of different modes: hydrophobic interactions (surfactant chains with CN side walls) or π-π interactions (aromatic rings of surfactants with CN surface). Infrared spectroscopy and atomic force microscopy were used for characterization of the systems studied. Finally, we focused on mechanical properties of cells exposed to surfactants and CN. This study was supported by the Ministry of Science and Higher Education (Poland), within the project “

Biophysical Journal, 112(3) S1, 156A (2017)

DOI: 10.1016/j.bpj.2016.11.858   (Pobrane:  2020-11-05)


232.

Ivashchenko O., Coy E., Peplińska B., Jarek M., Lewandowski M., Zaleski K., Warowicka A., Woźniak A., Babutina T., Jurga-Stopa J., Dolinsek J., Jurga S.

Influence of silver content on rifampicin adsorptivity for magnetite/Ag/rifampicin nanoparticles Magnetite nanoparticles (NPs) decorated with silver (magnetite/Ag) are intensively investigated due to their application in the biomedical field. We demonstrate that the increase of silver content on the surface of nanoparticles improves the adsorptivity of antibiotic rifampicin as well as antibacterial properties. The use of ginger extract allowed to improve the silver nucleation on the magnetite surface that resulted in an increase of silver content. Physicochemical and functional characterization of magnetite/Ag NPs was performed. Our results show that 5%-10% of silver content in magnetite/Ag NPs is already sufficient for antimicrobial properties against Streptococcus salivarius and Staphylococcus aureus. The rifampicin molecules on the magnetite/Ag NPs surface made the spectrum of antimicrobial activity wider. Cytotoxicity evaluation of the magnetite/Ag/rifampicin NPs showed no harmful action towards normal human fibroblasts, whereas the effect on human embryonic kidney cell viability was time and dose dependent.

Nanotechnology, 28(5), 055603 (2017)

DOI: 10.1088/1361-6528/28/5/055603


231.

Kardava I., Tadyszak K., Gulua N., Jurga S.

The software for automatic creation of the formal grammars using by speech recognition, computer vision, editable text conversion systems and some new functions For more flexibility of environmental perception by artificial intelligence it is needed to exist the supporting software modules, which will be able to automate the creation of specific language syntax and to make a further analysis for relevant decisions based on semantic functions. According of our proposed approach, of which implementation it is possible to create the couples of formal rules of given sentences (in case of natural languages) or statements (in case of special languages) by helping of computer vision, speech recognition or editable text conversion system for further automatic improvement. In other words, we have developed an approach, by which it can be achieved to significantly improve the training process automation of artificial intelligence, which as a result will give us a higher level of self-developing skills independently from us (from users). At the base of our approach we have developed a software demo version, which includes the algorithm and software code for the entire above mentioned component's implementation (computer vision, speech recognition and editable text conversion system). The program has the ability to work in a multi - stream mode and simultaneously create a syntax based on receiving information from several sources.

Proceedings of SPIE - Eighth International Conference on Graphic and Image Processing (ICGIP 2016), 10225, UNSP 102251Q (2017)

DOI: 10.1117/12.2267687


230.

Rajewsky N., Jurga S., Barciszewski J. (Eds.)

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Plant epigenetics This book presents, in 26 chapters, the status quo in epigenomic profiling. It discusses how functional information can be indirectly inferred and describes the new approaches that promise functional answers, collectively referred to as epigenome editing. It highlights the latest important advances in our understanding of the functions of plant epigenomics and new technologies for the study of epigenomic marks and mechanisms in plants. Topics include the deposition or removal of chromatin modifications and histone variants, the role of epigenetics in development and response to environmental signals, natural variation and ecology, as well as applications for epigenetics in crop improvement. Discussing areas ranging from the complex regulation of stress and heterosis to the precise mechanisms of DNA and histone modifications, it presents breakthroughs in our understanding of complex phenotypic phenomena.

Diagnostics. Book Series: RNA Technologies, Rajewski N., Jurga S., Barciszewski J. (Eds.),, , V-VII, Springer-Verlag Berlin, Heidelberger Platz 3, d-14197 Berlin, Germany (2017)


ISBN: 978-3-319-55520-1


229.

Pyziak M.A., Bartkowiak G., Popenda Ł., Jurga S., Schroeder G.

Synthesis of G0 aminopolyol and aminosugar dendrimers, controlled by NMR and MALDI TOF mass spectrometry Organic compounds designed to serve as stable dendrimer cores were developed. A series of aminosugar and amino polyol containing G0 dendrimers were synthesized. The reaction mixture composition was checked by MALDI TOF mass spectrometry, while that of purified products - by H-1 and C-13 NMR combined with 2D NMR spectroscopy as well as MALDI TOF MSMS mass spectra. Mass spectrometric fragmentation experiments were performed in positive ion mode in order to determine common fragmentation patterns of [M+H](+) ions.

Designed Monomers and Polymers, 20, 144-156 (2017)

DOI: 10.1080/15685551.2016.1231048


228.

Coy E. Yate L., Kabacińska Z., Jancelewicz M., Jurga S., Iatsunskyi I.

Topographic reconstruction and mechanical analysis of atomic layer deposited Al2O3/TiO2 nanolaminates by nanoindentation A novel method of nanomechanical testing of multilayered Al2O3/TiO2 nanolaminates was implemented by the nanoindentation technique. The indentation data were reconstructed and filtered by a statistical analysis algorithm and presented as a function of the penetration depth of the indenter. Results show the increment of mechanical properties on the laminates as a function of the amorphous interfaces of the individual layers and the effective control of the wear rate of the structures for further applications. The results presented show both important insights on the mechanical behavior of nanolaminates and the further applicability of the reconstruction model for error reduction on mechanical testing of nanolaminate samples. boratory efficiencies of dye-sensitized

Materials & Design, 111, 584-591 (2016)

DOI: 10.1016/j.matdes.2016.09.030   (Pobrane:  2018-04-03)


227.

Warowicka A., Maciejewska B.M., Litowczenko J., Kościński M., Baranowska-Korczyc A., Jasiurkowska-Delaporte M., Kozioł K., Jurga S.

MWCNT based matrices as a platform for adhesion and growth of cells In this study we examine multiwall carbon nanotube (MWCNT) based nanosystems i.e. aligned MWCNT matrices, as potential scaffolds for cell growth and tissue engineering. We present the effect of samples purification and surface modification on the viability, adhesiveness and morphology of human normal gingival fibroblasts (HGF-1) and human osteosarcoma (U2OS) cell lines. We employ spectroscopic and analytical techniques (Scanning Electron Microscopy, Thermal Gravimetric Analysis, Atomic Force Microscopy, Raman and Fourier Transform Infrared Absorption Spectroscopy and Confocal Microscopy) in order to characterize the obtained structures. Furthermore, we analyze the expression level of selected cell adhesion-related genes by the quantitative real-time (qRT-PCR) method and the cell viability for MWCNT powders. We show that the surface structure of MWCNTs carpets contributes to the adhesion of cells. Additionally, we report the increased expression level of integrin, talin and fibronectin, proteins which are involved in cell attachment. We speculate that carbon nanotube based materials can be consider as potential candidates for biomedical purposes and as a biocompatible scaffold for cell growth.

Composites Science and Technology, 136, 29-38 (2016)

DOI: 10.1016/j.compscitech.2016.09.026   (Pobrane:  2018-03-19)


226.

Shypylenko A., Pshyk A.V., Grześkowiak B., Medjanik K., Peplińska B., Oyoshi K., Pogrebnjak A., Jurga S., Coy E.

Effect of ion implantation on the physical and mechanical properties of Ti-Si-N multifunctional coatings for biomedical applications In the present work, multifunctional Ti-Si-N coatings have been deposited using CAVD method with the aim of studying their chemical, physical, structural and mechanical properties. Coatings of Ti-Si-N were modified by high-intensity ion implantation using copper ions with dose D = 2 x 10(17) ions/cm(2) and energy E = 60 keV. The results demonstrated that ion implantation has an effect on the grain size, hardness, and Young modulus of the Ti-Si-N coating. Additionally, the effect of Cu implantation on the bioactive properties of coatings was investigated by contact antimicrobial essay. The results show a high release of Cu ions in the cultivation liquid and the low efficiency of the <20% Cu doping towards E. coli bacteria. Our results bring understanding to the low dosage ion implantation of multifunctional surfaces towards applications and general drawbacks of ion implantation as bioactive tailoring method.

Materials & Design, 110, 821-829 (2016)

DOI: 10.1016/j.matdes.2016.08.050   (Pobrane:  2018-04-03)


225.

Pshyk A.V., Coy L.E., Nowaczyk G., Kęmpiński M., Peplińska B., Pogrebnjak A.D., Beresnev V.M., Jurga S.

High temperature behavior of functional TiAlBSiN nanocomposite coatings This article reports on the thorough characterization of structural-phase transformation in amorphous TiAlBSiN coating after high temperature annealing at 900 degrees C in ambient air. The influence of annealing on the tribo mechanical behavior of the coating at nano and micro scale was also examined. The research included multiple experimental techniques, i.e. AFM, SEM, TEM, HR-TEM, EDS, XPS and Raman spectroscopy. Experiments showed that the amorphous phase of the TiAlBSiN coating undergoes a structural transformation, evidenced in the changes of parameters such as topological and chemical short-range order after the post-deposition annealing at 900 degrees C in air. The observed structural transformation, leads to a phase separation with the formation of a three dimensional nc-TiAl3/a-SiBN(O) nanocomposite structure. The relative increase of hardness, reduced elastic modulus, H/Er ratio and H-2/E-r(3) ratio after high temperature treatment of TiAlBSiN coatings is also reported. The complex interdependency between chemistry, morphology and relative composition of the amorphous TiAlBSiN coating phase, during the high temperature treatment, with the respective change of the tribo-mechanical characteristics, are evidence of the improvement of the coating properties in response to the environmental conditions and high temperature. This work contributes particularly to the development and understanding of flexible nanocomposite protective coatings and their changes at high temperature of operation.

Surface & Coatings Technology, 305, 49-61 (2016)

DOI: 10.1016/j.surfcoat.2016.07.075


224.

Gołąbiewska A., Malankowska A., Jarek M., Lisowski W., Nowaczyk G., Jurga S., Zaleska-Medyńska A.

The effect of gold shape and size on the properties and visible light-induced photoactivity of Au-TiO2 In the present investigation, TiO2 modified with a different geometry and size of gold particles, such as nanospheres (NSPs), nanostars (NSTs) and nanorods (NRs), were prepared by the immobilization method. The effect of the gold shape, size and TiO2 matrix type (TiO2 microspheres or rutile TIO-6_TiO2) were systematically investigated. The obtained photocatalysts were thoroughly characterized by UV-vis diffuse-reflectance spectroscopy (DRS), BET surface area measurements, scanning electron microscopy (SEM), scanning transmission microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity under visible light (lambda> 420 nm) has been estimated in phenol degradation reaction in an aqueous phase. The significantly high photocatalytic activity under visible light irradiate as demonstrated by the TiO2 sample modified by spheres of gold. The average rate of phenol decomposition was 1.9 mu mol dm(-3) min(-1) and was three-times higher compared to the pristine TiO2 amorphous microspheres. On the other hand the photocatalytic activity was relatively lower and was 0.38 and 0.27 mu mol dm(-3) min(-1) for nanorods and nanostars deposited on the amorphous form of TiO2 microspheres, respectively. The visible light activity decreased in following order: (NSPs)> (NRs)> (NSTs). The obtained photocatalytic efficiency of samples was ascribed to the geometry and the size effect of the enhanced and the possible mechanism for this was discussed in detail. Furthermore, in this work we show the effect of calcination temperature on the structure of gold NPs, NRs and NSs before and after modification on the morphology and photocatalytic activity of Au-TiO2.

Applied Catalysis B: Bnvironmental, 196, 27-40 (2016)

DOI: 10.1016/j.apcatb.2016.05.013


223.

Falkowski M., Rębiś T., Piskorz J., Popenda Ł., Jurga S., Mielcarek J., Milczarek G., Gośliński T.

Improved electrocatalytic response toward hydrogen peroxide reduction of sulfanyl porphyrazine/multiwalled carbon nanotube hybrids deposited on glassy carbon electrodes We report on the synthesis, physico-chemical properties of magnesium sulfanyl porphyrazine derivatives with peripheral hyperbranched groups and their deposition on the multi-walled carbon nanotube surface. Sulfanyl porphyrazines containing bulky and dendrimeric peripheral benzyloxy units, mers, up to their second generation, were synthesized and characterized using MS, UV-Vis, FT-IR, NMR spectroscopy and HPLC. The morphology of the hybrid nanostructures was researched using SEM and AFM microscopy. Their potential for biomedicine and technology was assessed in an electrochemical study. The electrodes modified with dendrimeric sulfanyl porphyrazine/multiwalled carbon nanotube hybrids were utilized for electrocatalytic determination of hydrogen peroxide, which is an important compound generated in many enzymatic reactions. The strong synergistic effect between two nanostructural components, namely multi-walled carbon nanotubes and dendrimeric porphyrazines was evaluated in the electrochemical study. In the result a significant enhancement of electrochemical properties of the modified electrode was observed. The reversible redox couples derived from porphyrazine ring based electron transfer were responsible for the improvement of the electrocatalytic response of the modified electrode toward hydrogen peroxide reduction. According to the electrochemical results, multi-walled carbon nanotube - dendrimeric porphyrazine hybrids deposited on the surface of glassy carbon electrode constitute a valuable material for enzyme free biosensor development.

Dyes and Pigments, 134, 569-579 (2016)

DOI: 10.1016/j.dyepig.2016.08.014


222.

Baitimirova M., Viter R., Andzane J., van der Lee A., Voiry D., Iatsunskyi I., Coy E., Mikoliunaite L., Tumenas S., Zaleski K., Balevicius Z., Baleviciute I., Ramanaviciene A., Ramanavicius A., Jurga S., Erts D., Bechelany M.

Tuning of structural and optical properties of graphene/ZnO nanolaminates Zinc oxide (ZnO) and graphene (G) have been extensively studied because of their unique physical properties. Here, graphene zinc oxide (G/ZnO) nanolaminates were fabricated, respectively, by chemical vapor deposition and low temperature atomic layer deposition technique. The number of obtained G/ZnO layers was tuned from 1 to 11 with a total thickness of 100 nm for all prepared nanolaminates. The structure, optical properties, and interaction between G and ZnO were studied by X-ray methods, TEM, AFM, Raman, and optical spectroscopy. The obtained results were interpreted and analyzed taking into account strain and charge effects of graphene in G/ZnO nanostructures. We demonstrate that the bottom graphene used as a substrate stimulated the formation of ZnO crystalline structure. n-Doping of graphene caused by charge transfer from ZnO to graphene has been detected by blue-shift of G-band of Raman spectra of the nanolaminates. ZnO photoluminescence intensity was found to be dependent on the number of graphene layers in G/ZnO nanolaminate. n-Doping of graphene could be tailored by controlling the construction of the G/ZnO nanolaminates for a variety of applications such as selective adsorption of the target molecules on graphene surface. Thus, G/ZnO nanolaminates may find applications in optical, bio-, and chemical sensors.

Journal of Physical Chemistry C, 120(41), 23716-23725 (2016)

DOI: 10.1021/acs.jpcc.6b07221   (Pobrane:  2021-01-27)


221.

Leszczyński B., Hadjipanayis G.C., El-Gendy A.A., Zaleski K., Śniadecki Z., Musiał A., Jarek M., Jurga S., Skumiel A.

The influence of oxidation process on exchange bias in egg-shaped FeO/Fe3O4 core/shell nanoparticles Egg-shaped nanoparticles with a core shell morphology were synthesized by thermal decomposition of an iron oleate complex. XRD and M(T) magnetic measurements confirmed the presence of FeO (wustite) and Fe3O4 (magnetite) phases in the nanoparticles. Oxidation of FeO to Fe3O4 was found to be the mechanism for the shell formation. As-made nanoparticles exhibited high values of exchange bias at 2 K. Oxidation led to decrease of exchange field from 2880 Oe (in as-made sample) to 330 Oe (in oxidized sample). At temperatures higher than the Neel temperature of FeO (200 K) there was no exchange bias. An interesting observation was made showing the exchange field to be higher than the coercive field at temperatures close to magnetite's Verwey transition.

Journal of Magnetism and Magnetic Materials, 416, 269-274 (2016)

DOI: 10.1016/j.jmmm.2016.05.023   (Pobrane:  2018-04-03)


220.

Zalas M., Wawrzyńczak A., Półrolniczak P., Sobuś J., Schroeder G., Jurga S., Selli E.

Effect of solvent variations in the alcothermal synthesis of template-free mesoporous titania for dye-sensitized solar cells applications A series of 14 mesoporous titania materials has been synthesized using the simple alcothermal template-free method and various alcohols, such as methanol, propanols and butanols, as solvents. All materials were characterized by both wide and small angle XRD, which exhibited the anatase phase with short-range ordered mesoporous structure that is still forming during post synthetic temperature treatment in most of the investigated materials. Nitrogen adsorption-desorption isotherms confirmed the mesoporous structure with surface area ranging from 241 to 383 m(2)g(-1) and pore volumes from 0.162 to 0.473 m(3)g(-1), UV-Vis diffuse reflectance showed the redshift of the absorption edge and the bandgap decrease after post synthetic calcination of the materials presented. The TEM, FT-IR, DTA and TG measurements have been made to well characterize the materials synthesized. The mesoporous samples obtained were applied as anode materials for dye-sensitized solar cells and showed good activity in photon-to-current conversion process with efficiency values ranging from 0.54% to 4.6% and fill factors in the 52% to 67% range. The photovoltaic performances were not as high as those obtained for the materials synthesized by us earlier employing ethanol as a solvent. The differences in the electron lifetime, calculated from electrochemical impedance spectroscopy results and varying between 4.3 to 17.5 ms, were found as a main factor determining the efficiency of the investigated photovoltaic cells.

PloS ONE, 11(10), e0164670 (2016)

DOI: 10.1371/journal.pone.0164670   (Pobrane:  2018-04-05)


219.

Śliwińska M., Garcia-Hernandez C., Kościński M., Dymerski T., Wardencki W., Namieśnik J., Śliwińska-Bartkowiak M., Jurga S., Garcia-Cabezon C., Rodriguez-Mendez M.L.

Discrimination of apple liqueurs (nalewka) using a voltammetric electronic tongue, uv-vis and raman spectroscopy The capability of a phthalocyanine-based voltammetric electronic tongue to analyze strong alcoholic beverages has been evaluated and compared with the performance of spectroscopic techniques coupled to chemometrics. Nalewka Polish liqueurs prepared from five apple varieties have been used as a model of strong liqueurs. Principal Component Analysis has demonstrated that the best discrimination between liqueurs prepared from different apple varieties is achieved using the e-tongue and UV-Vis spectroscopy. Raman spectra coupled to chemometrics have not been efficient in discriminating liqueurs. The calculated Euclidean distances and the k-Nearest Neighbors algorithm (kNN) confirmed these results. The main advantage of the e-tongue is that, using PLS-1, good correlations have been found simultaneously with the phenolic content measured by the Folin-Ciocalteu method (R of 0.97 in calibration and R of 0.93 in validation) and also with the density, a marker of the alcoholic content method (R of 0.93 in calibration and R of 0.88 in validation). UV-Vis coupled with chemometrics has shown good correlations only with the phenolic content (R of 0.99 in calibration and R of 0.99 in validation) but correlations with the alcoholic content were low. Raman coupled with chemometrics has shown good correlations only with density (R of 0.96 in calibration and R of 0.85 in validation). In summary, from the three holistic methods evaluated to analyze strong alcoholic liqueurs, the voltammetric electronic tongue using phthalocyanines as sensing elements is superior to Raman or UV-Vis techniques because it shows an excellent discrimination capability and remarkable correlations with both antioxidant capacity and alcoholic content-the most important parameters to be measured in this type of liqueurs.

Sensors, 16(10), 1654 (2016)

DOI: 10.3390/s16101654   (Pobrane:  2018-04-03)


218.

Przysiecka Ł., Michalska M., Nowaczyk G., Peplińska B., Jesionowski T., Schneider R., Jurga S.

iRGD peptide as effective transporter of CuInZnxS2+x quantum dots into human cancer cells In this paper, iRGD peptide-mediated quantum dots (QDs) delivery was studied. In the first step, dodecanethiol-capped CulnZn(x)S(2+x) (ZCIS) QDs were prepared and subsequently transferred into water using a standard and facile ligand exchange approach involving 3-mercaptopropionic acid (MPA). ZCIS@MPA nanocrystals possess a photoluminescence quantum yield (PL QY) of 25%, a PL emission centered at ca. 640nm and low distributions in size and shape. Next, the iRGD peptide was electrostatically associated to ZCIS@MPA QDs. After cytotoxicity evaluation, the tumor-targeting and penetrating activities of the iRGD/QD assembly were investigated by confocal microscopy. The experiments performed on various cancer cell lines revealed a high penetration ability of the assembly, while the bare QDs were not internalized. Additionally, imaging experiments were conducted on three-dimensional multicellular tumor spheroids in order to mimic the tumor microenvironment in vivo. iRGD/QD assemblies were found to be evenly distributed throughout the whole HeLa spheroid contrary to normal cells where they were not present. Therefore, iRGD/QD assemblies have a great potential to be used as targeted imaging agents and/or nanocarriers specific to cancer cells.

Colloids and Surfaces B: Biointerfaces, 146, 9-18 (2016)

DOI: 10.1016/j.colsurfb.2016.05.041   (Pobrane:  2018-04-03)


217.

Majorosova J., Petrenko V.I., Siposova K., Timko M., Tomasovicova N., Garamus V.M., Koralewski M., Avdeev M.V., Leszczyński B., Jurga S., Gazova Z., Hayryan S., Hu C-K, Kopcansky P.

On the adsorption of magnetite nanoparticles on lysozyme amyloid fibrils An adsorption of magnetic nanoparticles (MNP) from electrostatically stabilized aqueous ferrofluids on amyloid fibrils of hen egg white lysozyme (HEWL) in 2 mg/mL acidic dispersions have been detected for the MNP concentration range of 0.01-0.1 vol.%. The association of the MNP with amyloid fibrils has been characterized by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS) and magneto-optical measurements. It has been observed that the extent of adsorption is determined by the MNP concentration. When increasing the MNP concentration the formed aggregates of magnetic particles repeat the general rod-like structure of the fibrils. The effect is not observed when MNP are mixed with the solution of lysozyme monomers. The adsorption has been investigated with the aim to clarify previously found disaggregation activity of MNP in amyloid fibrils dispersions and to get deeper insight into interaction processes between amyloids and MNP. The observed effect is also discussed with respect to potential applications for ordering lysozyme amyloid fibrils in a liquid crystal phase under external magnetic fields.

Colloids and Surfaces B: Biointerfaces, 146, 794-800 (2016)

DOI: 10.1016/j.colsurfb.2016.07.024   (Pobrane:  2021-01-20)


216.

Jenczyk J., Jurga S.

Complementary studies of NMR spin diffusion and atomic force microscopy - Structural characterization of diblock copolymers Due to their unique microphase structure copolymer systems have become important potential candidates for nanolitographic purposes. In order to properly design copolymeric templates a complete characterization of the phase separated system is required. Due to the fact that structural analysis of organic compounds remains demanding, especially when it comes to nanometer scale features such as interfacial spaces, there are very often at least two complementary experimental techniques employed to fully characterize observed morphologies. In this work diblock copolymers of poly (styrene)-b-poly (ethylene oxide) (PS-PEO) with three different molecular weights were investigated. Two different experimental methods were used: nuclear magnetic resonance spectroscopy (NMR) and atomic force microscopy (AFM). AFM topographic images of self-assembled polymer films enabled estimation of average interdomain distances, whereas the NMR spin diffusion experiment provided structural parameters related to stiff PS domains and interfacial space thickness. An application of two complementary methods enabled complete description of the studied morphologies and revealed substantial differences in polymer chain mobility between two distinct phases.

Polymer, 99, 90-96 (2016)

DOI: 10.1016/j.polymer.2016.07.006


215.

Wołoszczuk S., Jurga S., Banaszak M.

Towards entropy-driven interstitial micelles at elevated temperatures from selective A1BA2 triblock solutions We simulate selective A1BA2-A and A1BA2-B triblock solutions (that is, mixtures of the A1BA2 triblock with a solvent of either type A or type B) using a lattice Monte Carlo method. Although the simulated triblock chains are compositionally symmetric in terms of the A to B volume ratio, the A1 block is significantly shorter than the A2 block. For the pure A1BA2 melt the phase behavior is relatively well known, including the existence and stability of the recently discovered interstitial micelles which were found at the very strong segregation limit. In this paper, we investigate the stability of the interstitial micelles as a function of triblock volume fraction in a selective solvent of either type A or type B. The main finding of this paper is that adding a selective solvent of type A shifts the stability of the interstitial micelles into significantly higher temperatures which may provide a pathway towards experimental studies of interstitial micelles in real triblock solutions. We also find that adding selective solvents to the A1BA2 melt gives rise to a variety of nonlamellar nanostructures for temperatures and compositions at which the interstitial micelles are stable.

Physical Review E, 94(2), 022502 (2016)

DOI: 10.1103/PhysRevE.94.022502   (Pobrane:  2020-10-23)


214.

Woźniak-Budych M.J., Langer K., Peplińska B., Przysiecka Ł., Jarek M., Jarzębski M., Jurga S.

Copper-gold nanoparticles: Fabrication, characteristic and application as drug carriers In this investigation, the fabrication of porous core/shell nanostructures consisting of copper (core) and copper-gold nanoalloy (shell) for medical applications is presented. As a core triangular-shaped copper nanoparticles were used. The porous bimetallic nanoshell was prepared via galvanic reaction in the presence of oil-in water emulsion. It was proved that porous nanoalloy layer can be prepared at pH 7 and in the presence 0.1% and 0.5% oil-in water emulsion. The porous structure fabrication was mainly determined by volume fraction of hexadecane to acetone in the oil-in water emulsion and Zeta-potential of emulsion droplets (pH of emulsion). The influence of emulsion droplets size before galvanic reaction on porous structure preparation was negligible. It was found that doxorubicin could be easily introduced and released from porous core/shell nanostructures, due to spontaneous adsorption on the copper-gold nanoporous surface. The in vitro test showed that cytotoxic effect was more prominent once the doxorubicin was adsorbed on the porous copper-gold nanocarriers. It was demonstrated, that doxorubicin-loaded copper-gold nanostructures caused inhibition cell proliferation and viability of cancer cells, in a concentration-dependent manner. The results indicates that presented toper-gold nanocarrier have potential to be used in targeted cancer therapy, due to its porous structure and cytotoxic effect in cancer cells.

Materials Chemistry and Physics, 179, 242-253 (2016)

DOI: 10.1016/j.matchemphys.2016.05.036   (Pobrane:  2020-10-23)


213.

Bajerlein D., Adamski Z., Kacalak W., Tandecka K., Wiesner M., Jurga S.

To attach or not to attach? The effect of carrier surface morphology and topography on attachment of phoretic deutonymphs of Uropoda orbicularis (Acari) Previous studies on preferences of phoretic deutonymphs of Uropodina for attachment sites have shown that they frequently select smooth and hydrophobic surfaces. The aim of our study was to provide the detailed morphological and topographical characteristics of beetle body surfaces to which deutonymphs frequently attach and to verify how the presence of setae and surface sculpture affects deutonymph attachment. The study was conducted on Uropoda orbicularis (Muller, 1776) and its common beetle carriers: Aphodius prodromus (Brahm, 1790), Aphodius fimetarius (Linnaeus, 1758), Onthophagus nuchicornis (Linnaeus, 1758) and Margarinotus carbonarius (Hoffmann, 1803). Morphology and topography of elytra, femora, propygidia and pygidia of beetles were analysed mainly using SEM methods supported with CLSM and AFM techniques. The hypothesis that deutonymphs may attach to surfaces covered with setae, if seta density is low enough not to disturb mite movement, was tested. The study revealed that deutonymphs attach to surfaces of various types as follows: (i) smooth, (ii) hairy, i.e., covered with setae, (iii) flat and (iv) sculptured. Smooth body parts and body parts covered with setae of low density were most frequently and intensively occupied with deutonymphs. Surfaces of high seta density were avoided by mites. Within elytra of Aphodius beetles, deutonymphs definitely preferred flat surfaces of elytral intervals. On the contrary, densely punctuated propygidium and pygidium in M. carbonarius were heavily infested with deutonymphs. We conclude that carrier surface morphology and topography are important for Uropodina deutonymph attachment, but these two factors cannot fully explain the observed relation.

Science of Nature, 103(7-8), 1-17 (2016)

DOI: 10.1007/s00114-016-1385-9   (Pobrane:  2020-10-21)


212.

Pogrebnjak A.D., Bondar O.V., Abadias G., Ivashchenko V., Sobol O.V., Jurga S., Coy E.

Structural and mechanical properties of NbN and Nb-Si-N films: Experiment and molecular dynamics simulations The structural and mechanical properties of NbN and Nb-Si-N films have been investigated both experimentally and theoretically, in their as-deposited and annealed states. The films were deposited using magnetron sputtering at substrate bias (U-B) between 0 and -70 V. While NbN films were found to crystallize in the cubic delta-NbN structure, Nb-Si-N films with Si content of 11-13 at% consisted of a two phases nanocomposite structure where delta-NbN nanocrystals were embedded in SiNx amorphous matrix. Films deposited at U-B = 0 V were highly (001)-textured. Application of substrate bias potential led to a depletion of light atoms, and caused a grain size refinement concomitantly with the increase of (111) preferred orientations in both films. The maximum hardness was 28 GPa and 32 GPa for NbN and Nb-Si-N films, respectively. NbN and Nb-Si-N filais deposited at U-B = -70 V exhibited compressive stress of -3 and -4 GPa, respectively. After vacuum annealing, a decrease in the stress-free lattice parameter was observed for both films, and attributed to alteration of film composition. To obtain insights on interface properties and related mechanical and thermal stability of Nb-Si-N nanocomposite films, first principles molecular dynamics simulations of NbN/SiNx heterostructures with different structures (cubic and hexagonal) and atomic configurations were carried out. All the hexagonal heterostructures were found to be dynamically stable and weakly dependent on temperature. Calculation of the tensile strain-stress curves showed that the values of ideal tensile strength for the delta-NbN(111)- and epsilon-NbN(001)-based heterostructures with coherent interfaces and Si3N4-like Si2N3 interfaces were the highest with values in the range 36-65 GPa, but lower than corresponding values of bulk NbN compound. This suggests that hardness enhancement is likely due to inhibition of dislocation glide at the grain boundary rather than interfacial strengthening due to Si-N chemical bonding. (C) 2016 Elsevier Ltd and Techna Group S.r.l.

Ceramics International, 42(10), 11743-11756 (2016)

DOI: 10.1016/j.ceramint.2016.04.095   (Pobrane:  2018-04-03)


211.

Babayevska N., Nowaczyk G., Jarek M., Zaleski K., Jurga S.

Synthesis and study of bifunctional core-shell nanostructures based on ZnO@Gd2O3 Bifunctional nanostructures based on ZnO nanoparticles (NPs) with controlled Gd2O3 shell thicknesses were obtained by simple low-temperature methods (sol-gel technique and seed deposition method). The morphology, nanostructure, phase and chemical composition as well as luminescent and magnetic properties of the obtained core-shell nanostructures were investigated by transmission electron microscopy (HRTEM), energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD) techniques, optical spectroscopy, and SQUID magnetometer. As-obtained ZnO NPs are highly monodispersed and crystalline with mean particles size distribution of about 7 nm. Modification of the ZnO NPs surface by Gd2O3 shell leads to an increase of the ZnO particles size up to 80-160 nm and the formation the Gd2O3 shell with size of 2-4 nm. The dependence of the phase composition, luminescent and magnetic properties on Gd2O3 content are also discussed. © 2016 Elsevier B.V. All rights reserved.

Journal of Alloys and Compounds, 672, 350-355 (2016)

DOI: 10.1016/j.jallcom.2016.02.189


210.

Reyes Y.C., Coy L.E., Yate L., Jurga S., Gonzalez E.E.

Nanostructured and selective filter to improve detection of arsenic on surface plasmon nanosensors The development of a pretreatment system to assist surface plasmon sensor-based measurement of arsenic in water is described. The system proposed addresses important issues, regarding the reliable in situ detection of arsenic in water. This system uses a primary filter made of nonactivated cotton fibers for particulate matter and chemical retention agents without modifying the arsenic concentration in the water sample. A secondary filter was designed for retention of mercury, lead, and other heavy metals without alteration of the arsenic concentration in the collected water samples to be sensed. This filter was made with amino-functionalized carbon nanotubes. The results of the operational assessment of this filter show a retention efficiency of 98% for suspended solids, 96% for mercury ions, and 2% for arsenic, a remarkable improvement toward the accurate detection and quantification of arsenic in contaminated waters.

ACS Sensors, 1(6), 725-731 (2016)

DOI: 10.1021/acssensors.6b00211


209.

Młynarczyk D.T., Lijewski S., Falkowski M., Piskorz J., Szczółko W., Sobotta Ł., Stolarska M., Popenda Ł., Jurga S., Konopka K., Duzgunes N., Mielcarek J., Goślinski T,

Dendrimeric sulfanyl porphyrazines: synthesis, physico-chemical characterization, and biological activity for potential applications in photodynamic therapy Sulfanyl porphyrazines substituted at their periphery with different dendrimeric moieties up to their first generation were synthesized and characterized by photochemical and biological methods. The presence of a dendrimeric periphery enhanced the spectral properties of the porphyrazines studied. The singlet-oxygen-generation quantum yield of the obtained macrocycles ranged from 0.02 to 0.20 and was strongly dependent on the symmetry of the compounds and the terminal groups of the dendritic outer shell. The in vitro biological effects of three most promising tribenzoporphyrazines were examined; the results indicated their potential as photosensitizers for photodynamic therapy (PDT) against two oral squamous cell carcinoma cell lines derived from the tongue. The highest photocytotoxicity was found for sulfanyl tribenzoporphyrazine that possessed 4-[3,5-di(hydroxymethyl) phenoxy] butyl substituents with nanomolar IC50 values at 10 and 42 nm against CAL 27 and HSC-3 cell lines, respectively.

ChemPlusChem, 81(5), 460-470 (2016)

DOI: 10.1002/cplu.201600051


208.

Grześkowiak B., Hryhorowicz M., Tuśnio K., Grzeszkowiak M., Zaleski K., Lipiński D., Zeyland J., Mykhaylyk Olga., Słomski R., Jurga S., Woźniak A.

Generation of transgenic porcine fibroblast cell lines using nanomagnetic gene delivery vectors The transgenic process allows for obtaining genetically modified animals for divers biomedical applications. A number of transgenic animals for xenotransplantation have been generated with the somatic cell nuclear transfer (SCNT) method. Thereby, efficient nucleic acid delivery to donor cells such as fibroblasts is of particular importance. The objective of this study was to establish stable transgene expressing porcine fetal fibroblast cell lines using magnetic nanoparticle-based gene delivery vectors under a gradient magnetic field. Magnetic transfection complexes prepared by self-assembly of suitable magnetic nanoparticles, plasmid DNA, and an enhancer under an inhomogeneous magnetic field enabled the rapid and efficient delivery of a gene construct (pCD59-GFPBsd) into porcine fetal fibroblasts. The applied vector dose was magnetically sedimented on the cell surface within 30min as visualized by fluorescence microscopy. The PCR and RT-PCR analysis confirmed not only the presence but also the expression of transgene in all magnetofected transgenic fibroblast cell lines which survived antibiotic selection. The cells were characterized by high survival rates and proliferative activities as well as correct chromosome number. The developed nanomagnetic gene delivery formulation proved to be an effective tool for the production of genetically engineered fibroblasts and may be used in future in SCNT techniques for breeding new transgenic animals for the purpose of xenotransplantation.

Molecular Biotechnology, 58(5), 351-61 (2016)

DOI: 10.1007/s12033-016-9934-1


207.

Robak E., Coy E., Kotkowiak M., Jurga S., Załęski K., Drozdowski H.

The effect of Cu doping on the mechanical and optical properties of zinc oxide nanowires synthesized by hydrothermal route Zinc oxide (ZnO) is a wide-bandgap semiconductor material with applications in a variety of fields such as electronics, optoelectronic and solar cells. However, much of these applications demand a reproducible, reliable and controllable synthesis method that takes special care of their functional properties. In this work ZnO and Cu-doped ZnO nanowires are obtained by an optimized hydrothermal method, following the promising results which ZnO nanostructures have shown in the past few years. The morphology of as-prepared and copper-doped ZnO nanostructures is investigated by means of scanning electron microscopy and high resolution transmission electron microscopy. X-ray diffraction is used to study the impact of doping on the crystalline structure of the wires. Furthermore, the mechanical properties (nanoindentation) and the functional properties (absorption and photoluminescence measurements) of ZnO nanostructures are examined in order to assess their applicability in photovoltaics, piezoelectric and hybrids nanodevices. This work shows a strong correlation between growing conditions, morphology, doping and mechanical as well as optical properties of ZnO nanowires.

Nanotechnology, 27(17), 175706 (2016)

DOI: 10.1088/0957-4484/27/17/175706   (Pobrane:  2018-04-03)


206.

Michalska M., Florczak A., Dams-Kozłowska H., Gapiński J., Jurga S., Schneider R.

Peptide-functionalized ZCIS QDs as fluorescent nanoprobe for targeted HER2-positive breast cancer cells imaging In this paper, the synthesis of alloyed CuInZnxS2+x quantum dots (ZCIS QDs), their transfer into aqueous solution via a polymer coating technique, and the use of these nanocrystals to selectively target HER2-positive cells, are reported. By optimizing first the ZnS shell deposition process onto the CuInS2 core, and next the encapsulation of the dots with the amphiphilic poly(maleic anhydride-alt-1-octadecene) (PMAO) polymer, water-dispersible ZCIS QDs were successfully prepared. The nanocrystals with a photoluminescence quantum yield of 35% were purified via centrifugation and ultracentrifugation and high quality nanoparticles with narrow size distributions and surface charges were obtained. After verifying the biocompatibility of PMO-coated ZCIS QDs, we coupled these nanocrystals with the LTVSPWY peptide and demonstrated via MTT assay that both bare and the peptide-linked QDs exhibit low cytotoxicity. The HER2-mediated delivery of the peptide-linked QDs was confirmed by confocal microscopy. This study indicates that as engineered QDs can efficiently be used as fluorescent nanoprobes for selective labelling of HER2-positive SKBR3 cancer cells. Copyright 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Acta Biomaterialia, 35, 293-304 (2016)

DOI: 10.1016/j.actbio.2016.02.002   (Pobrane:  2018-04-05)


205.

Wieczorek E., Gierszewski M., Popenda Ł., Tykarska E., Gdaniec M., Jurga S., Sikorski M., Mielcarek J., Piskorz J., Gośliński T.

Synthesis, characterization and photophysical properties of novel 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles Three 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles with bulky 2-(3,5-dibromophenyl)ethenyl, 2-(4-tert-butylphenyl)ethenyl and 2-(3,5-dibenzyloxyphenyl)ethenyl substituents were synthesized and characterized using UV-Vis, MS ES, elemental analysis and NMR spectroscopy. NMR data indicated that diazepine rings of all obtained compounds adopted 6H-tautomeric form. In addition, trans-isomerism within styryl substituents was observed. Experimental data for diazepine derivative containing 2-(4-tertbutylphenyl)ethenyl substituents were verified by X-ray crystallography. The obtained compounds were subjected to photophysical studies. In the UV-Vis absorption spectra two characteristic bands were found. In the solvatochromic study, the first band maxima were located in the range of 384-418 nm, whereas second band maxima in the range of 313-345 nm. Fluorescence intensity of novel diazepine derivatives was rather low in all solvents used with the values of fluorescence quantum yield Phi(F) (=) 10(-4) for 2-(3,5-dibromophenyl)ethenyl, and 10(-5) for 2-(4-tert-butylphenyl)ethenyl and 3,5-(dibenzyloxyphenyl)ethenyl 1,4-diazepine-2,3-dicarbonitriles. (C) 2016 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 110, 208-214 (2016)

DOI: 10.1016/j.molstruc.2016.01.032


204.

Tillo A., Stolarska M., Kryjewski M., Popenda Ł., Sobotta Ł., Jurga S., Mielcarek J., Gośliński T.

Phthalocyanines with bulky substituents at non-peripheral positions - Synthesis and physico-chemical properties Three novel phthalocyanine derivatives equipped with bulky substituents at non-peripheral positions were synthesized and their physico-chemical properties were analyzed. Singlet oxygen generation as well as the aggregation properties of the phthalocyanines with different sizes of peripheral substituents were thoroughly studied. An insertion of benzyloxy or 3,5-bis(benzyloxy)benzyloxy groups to the non peripheral positions of phthalocyanines increased the singlet oxygen generation efficacy compared with a phthalocyanine substituted with 2-propoxy groups. (C) 2015 Elsevier Ltd. All rights reserved.

Dyes and Pigments, 127, 110-115 (2016)

DOI: 10.1016/j.dyepig.2015.12.017   (Pobrane:  2018-04-03)


203.

Gurzęda B., Florczak P., Kempiński M., Peplińska B., Krawczyk P., Jurga S.

Synthesis of graphite oxide by electrochemical oxidation in aqueous perchloric acid In this research a graphite oxide (GO) was synthesized by electrochemical oxidation of natural graphite in aqueous solution of perchloric acid. The process of anodic oxidation of graphite was performed by linear sweep voltammetry (LSV) from the rest potential of electrode to 1.4 V. In consequence of the electrochemical treatment graphite was fully transformed yielding GO. Formation of GO was proved by X-ray diffraction (XRD) and Raman spectroscopy analysis. The synthesis product was also characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).
(C) 2016 Elsevier Ltd. All rights reserved.

Carbon, 100, 540-545 (2016)

DOI: 10.1016/j.carbon.2016.01.044   (Pobrane:  2020-10-21)


202.

Pshyk A.V., Coy E.L., Yate L., Załęski K., Nowaczyk G., Pogrebnjak A.D., Jurga S.

Combined reactive/non-reactive DC magnetron sputtering of high temperature composite AlN-TiB2-TiSi2 High temperature composite target AlN-TiB2-TiSi2 with heterogeneous distribution of compounds (AlN-50 wt.%; TiB2-35 wt.%; TiSi2-15 wt.%) is used for sputtering via combined reactive/non-reactive DCmagnetron sputtering onto substrate materials either cylindrical polished steel (Fe, 18%-Ni, 12%-Cr, 10%-Ti) 3mm diameter or monocrystalline silicon. The gradient coating has been produced by sequential non-reactive and reactive sputtering of the target. The structural and morphological properties of the deposited films are analyzed by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The tribo-mechanical properties are studied by means of nanoindentation and nanowear tests. The gradient film is composed of two layers with different microstructure and elemental composition. The first layer with thickness similar to 200 nm is mainly based on light B, C and N as well metal elements Al, Si and Ti. The presence of very well distributed nanocrystals embedded in an amorphous matrix, with crystal sizes ranging from 5 to 40 nm is observed in the second layer similar to 700 nm thickness and composed of Al, Ti, Si, B, and N. Films show very flat surfaces, with roughness around 0.35 nm. The hardness, elastic modulus, elastic recovery (W-e), H/E* ratio and H-3/E*(2) ratio are determined as 17.55 GPa, 216.7 GPa, 60%, 0.08 and 0.12 GPa, respectively. Nanowear tests demonstrate relatively high wear resistance of the coatings. Samples show promising characteristics for hard protective adaptive coatings and diffusion barriers due to short propagation of dislocations in the amorphous matrix and the elastic and hard nature of the nanocomposite structure.
(C) 2016 Elsevier Ltd. All rights reserved.

Materials & Design, 94, 230-239 (2016)

DOI: 10.1016/j.matdes.2015.12.174   (Pobrane:  2020-10-21)


201.

Viter R., Iatsunskyi I., Fedorenko V., Tumenas S., Balevicius Z., Ramanayicius A., Balme S., Kempinski M., Nowaczyk G., Jurga S., Bechelany M.

Enhancement of electronic and optical properties of zno/al2o3 nanolaminate coated electrospun nanofibers Nanolaminates are new class of promising nanomaterials with outstanding properties. Here we explored on the tuning of structural properties and the enhancement of electronic and optical properties of 1D PAN ZnO/Al2O3 nanolaminates designed by atomic layer deposition (ALD) and electrospinning. The influence of ZnO/Al2O3 bilayer thicknesses on the fundamental properties of 1D PAN ZnO/Al2O3 nanolaminates has been investigated. Due to the quantum confinement effect, the shift of XPS peaks to higher energies has been observed. Work function of Al2O3 was mostly independent of the bilayers number, whereas the ZnO work function decreased with an increase of the bilayer number. Photoluminescence of the 1D PAN ZnO/Al2O3 nanolaminates corresponded to emission bands in ZnO nanolayers. Due to quantum confinement and surface band bending, no excitonic peaks were observed. The defect emission band was affected by the band bending and defect concentration. The enhanced photoluminescence of the 1D PAN ZnO/Al2O3 nanolaminates allows applications in optical (bio)sensing field.

Journal of Physical Chemistry C, 120(9), 5124-5132 (2016)

DOI: 10.1021/acs.jpcc.5b12263   (Pobrane:  2018-04-04)


200.

Ivashchenko O., Jurga-Stopa J., Coy E., Peplińska B., Pietralik Z., Jurga S.

Fourier transform infrared and Raman spectroscopy studies on magnetite/Ag/antibiotic nanocomposites This article presents a study on the detection of antibiotics in magnetite/Ag/antibiotic nanocomposites using Fourier transform infrared (FTIR) and Raman spectroscopy. Antibiotics with different spectra of antimicrobial activities, including rifampicin, doxycycline, cefotaxime, and ceftriaxone, were studied. Mechanical mixtures of antibiotics and magnetite/Ag nanocomposites, as well as antibiotics and magnetite nanopowder, were investigated in order to identify the origin of FTIR bands. FTIR spectroscopy was found to be an appropriate technique for this task. The spectra of the magnetite/Ag/antibiotic nanocomposites exhibited very weak (for doxycycline, cefotaxime, and ceftriaxone) or even no (for rifampicin) antibiotic bands. This FTIR “invisibility” of antibiotics is ascribed to their adsorbed state. FTIR and Raman measurements show altered C—O, C=O, and C—S bonds, indicating adsorption of the antibiotic molecules on the magnetite/Ag nanocomposite structure. In addition, a potential mechanism through which antibiotic molecules interact with magnetite/Ag nanoparticle surfaces is proposed.
© 2015 Elsevier B.V. All rights reserved.

Applied Surface Science, 364, 400-409 (2016)

DOI: 10.1016/j.apsusc.2015.12.149   (Pobrane:  2017-12-08)


199.

Jenczyk J., Coy E., Jurga S.

Poly(ethylene oxide)-block-polystyrene thin films morphology controlled by drying conditions and substrate topography Thin polymer films made of polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymer were deposited via spin-coating technique on thermally reconstructed sapphire substrates in order to obtain self-assembled polymer matrices characterized by long range domain ordering. This approach, under specific solvent vapor annealing conditions, enabled us to fabricate polymer films exhibiting quasi long-range crystalline organization of hexagonally packed PEO cylinders aligned perpendicularly with respect to the substrate surface. In order to find an optimal conditions for thin film fabrication, the influence of moisture annealing process on polymer films morphology was examined. Different drying conditions revealed semicrystalline nature of poly(ethylene oxide) block. Consequently, apart from regular amorphous layers, various crystalline forms were also observed, including dendritic crystals, densely branched structures and square shaped single crystals. Presented data show how strongly the polymer film morphology depends on annealing conditions.

European Polymer Journal, 75, 234-242 (2016)

DOI: 10.1016/j.eurpolymj.2015.12.020   (Pobrane:  2018-04-04)


198.

Tadyszak K., Boś-Liedke A., Jurga J., Baranowski M., Mrówczynski R., Chlewicki W., Jurga S., Czechowski T.

Overmodulation of projections as signal-to-noise enhancement method in EPR imaging A study concerning the image quality in electron paramagnetic resonance imaging in two-dimensional spatial experiments is presented. The aim of the measurements was to improve the signal-to-noise ratio (SNR) of the projections and the reconstructed image by applying modulation amplitude higher than the radical electron paramagnetic resonance linewidth. Data were gathered by applying four constant modulation amplitudes, where one was below 1/3 (Amod=0.04 mT) of the radical linewidth (ΔBpp=0.14 mT). Three other modulation amplitude values were used in this experiment, leading to undermodulated (Amod < 1/3 ΔBpp), partially overmodulated (Amod ∼ 1/3 ΔBpp) and fully overmodulated (Amod ≥ 1/3 ΔBpp) projections. The advantages of an applied overmodulation condition were demonstrated in the study performed on a phantom containing four shapes of 1.25 mM water solution of 2, 2, 6, 6-tetramethyl-1-piperidinyloxyl. It was shown that even when the overmodulated reference spectrum was used in the deconvolution procedure, as well as the projection itself, the phantom shapes reconstructed as images directly correspond to those obtained in undermodulation conditions. It was shown that the best SNR of the reconstructed images is expected for the modulation amplitude close to 1/3 of the projection linewidth, which is defined as the distance from the first maximum to the last minimum of the gradient-broadened spectrum. For higher modulation amplitude, the SNR of the reconstructed image is decreased, even if the SNR of the measured projection is increased.
(C) 2015 John Wiley & Sons, Ltd.

Magnetic Resonance in Chemistry, 54(2), 136-142 (2016)

DOI: 10.1002/mrc.4330   (Pobrane:  2020-10-25)


197.

Jurga S., Erdmann V.A., Barciszewski J.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

The power of modified nucleic acids preface This volume is comprised of 18 chapters, covering various aspects of DNA modification and RNA modified bases. It also discusses in detail circular RNA, therapeutic oligonucleotides and their different properties. The chemical nature of DNA, RNA, protein and lipids makes these macromolecules easily modifiable, but they are also susceptible to damage from both endogenous and exogenous agents. Alkylation and oxidation show a potential to disrupt the cellular redox equilibrium and cause cellular damage leading to inflammation and even chronic disease. Furthermore, DNA damage can drive mutagenesis and the resulting DNA sequence changes can induce carcinogenesis and cancer progression. Modified nucleosides can occur as a result of oxidative DNA damage and RNA turnover, and are used as markers for various diseases. To function properly some RNA needs to be chemically modified post-transcriptionally. Dysregulation of the RNA-modification pattern or of the levels of the enzymes that catalyze these modifications alters RNA functionality and can result in complex phenotypes, likely due to defects in protein translation. While modifications are best characterized in noncoding ribonucleic acids like tRNA and rRNA, coding mRNAs have also been found to contain modified nucleosides. This book is a valuable resource, not only for graduate students but also researchers in the fields of molecular medicine and molecular biology.

Diagnostics. Book Series: RNA Technologies, Erdmann V.A., Jurga S., Barciszewski J. (Eds.), , Springer-Verlag Berlin, Heidelberger Platz 3, d-14197 Berlin, Germany (2016)


ISBN: 978-3-319-34175-0   (Pobrane:  2018-04-04)


196.

Rogoz V.M., Ivashchenko V.I., Coy E., Kościnski M., Jurga S., Plyushchyk A.

Investigation of tribological and mechanical properties of Nb-Al-N coatings before and after annealing Coatings Nb-Al-N were deposited on a silicon substrate under argon and nitrogen by magnetron sputtering at a substrate temperature of 350 degrees C and a constant current of 250 mA at the aluminum cathode. The analysis of the dependence chemical composition, morphology, structure and mechanical properties of the annealing temperature were performed for different series of coatings. Coatings demonstrated high thermal stability after annealing to 1000 degrees C.

International Conference on Nanomaterials: Application & Properties (NAP), UNSP 01NTF11, (2016)

   (Pobrane:  2018-04-04)


195.

Shypylenko A., Pshyk A.V., Medjanik K., Peplińska B., Oyoshid K., Jurga S., Coy E.

Influence of ion implantation on the physical and mechanical properties of multifunctional coatings based on Ti-Si-N Current paper presents the results of investigating of multifunctional Ti-Si-N coatings. Ti-Si-N coatings have been deposited using CAVD method with the aim of studying their chemical, physical, structural and mechanical properties. Coatings of Ti-Si-N were modified by high-intensity ion implantation using copper ions with dose D = 2 x 10(17) ions/cm(2) and energy E = 60 keV. The results demonstrated that ion implantation has effect on grain size, hardness, and Young modulus of the Ti-Si-N coating.

International Conference on Nanomaterials: Application & Properties (NAP), UNSP 01NTF18, (2016)

   (Pobrane:  2018-04-04)


194.

Mikołajczyk A., Malankowska A.Nowaczyk G., Gajewicz A., Hirano S., Jurga S., Zaleska-Medyńska A., Puzyn T.

Combined experimental and computational approach to developing efficient photocatalysts based on Au/Pd-TiO2 nanoparticles Surface modified TiO2-based nanoparticles (the so-called second generation nanoparticles) have unique semiconducting properties. They act as efficient photocatalysts, demonstrating catalytic activity under UV-vis and light-emitting diode (mix-LED) light. Consequently, they can be used as versatile, low-cost, clean and environmentally benign components in many innovative solutions, e. g. treatment technology for a wide range of environmental pollutants. However, for commercial application of TiO2-based systems, it is crucial to develop nano-powders that can absorb light in the visible spectrum. Our investigation has demonstrated the potential benefits of using a chemoinformatics approach to obtaining knowledge on structural features responsible for the photocatalytic activity of second generation NPs under visible light. Through a combination of multiple linear regression (MLR) and a genetic algorithm (GA), we have developed a quantitative structure-properties relationship (Nano-QSPR) model (R-2 = 0.89, RMSEC = 1.67, Q(LOO)(2) = 0.82, RMSECV = 2.18, Q(EXT)(2) = 0.80, RMSEP = 1.46) based on the most relevant physicochemical properties that characterized selected Au/ Pd-TiO2 NPs. According to the developed Nano-QSPR model, the anatase phase and palladium content are the main factors responsible for the higher activity of Au/Pd-TiO2 photocatalysts under visible light. It should be noted that the methodology presented here can serve as an important starting point for further design of new nanomaterials with enhanced functionality, supported by chemoinformatics methods.

RSC Advances, 6(92), 89305-89312 (2016)

DOI: 10.1039/c6en00232c   (Pobrane:  2018-04-04)


193.

Woźniak A., Noculak A., Gapiński J., Kociołek D., Boś-Liedke A., Zalewski T., Grześkowiak B.F., Kołodziejczak A., Jurga S., Bański M., Misiewicz J., Podhorodecki A.

Cytotoxicity and imaging studies of beta-NaGdF4:Yb3+Er3+@PEG-Mo nanorods Multimodal imaging based on nanostructures has become a subject of interest for numerous biomedical laboratories. The main focus was placed on applying nanocrystals for the purpose of two types of clinical imaging (contrast and fluorescent agents) due to their excellent luminescence and/or paramagnetic properties. Such systems should also be characterized by low toxicity and high cellular uptake efficiency. Since bare rare earth fluoride nanocrystals influence the cell membrane integrity, it is expected that their coatings will improve biocompatibility profile, as well as increase hydrophilicity, dispersion and chemical stability. Hence, by synthesis of beta-NaGdF4:Yb3+Er3+ nanorods (NRs) coated with noncovalently bounded polyethylene glycol monooleate (PEG-Mo), it should be possible to obtain multimodal imaging biomarkers meeting established criteria. Synthesis of beta-NaGdF4:Yb3+Er3+@PEG-Mo NRs was performed by the co-precipitation method. These nanostructures were characterized in terms of their size, morphology, zeta potential, magnetic and optical properties as well as their cytotoxicity profile and cellular internalization was evaluated. It was shown that the shape and size of nanocrystals, namely 20 nm nanorods, present generally accepted parameters for biomedical purpose. Ligand attraction of PEG-Mo 860 resulted in the encapsulation of oleic acid coated NRs and formation of hydrophilic bilayer. Superparamagnetic and luminescence properties were highly efficient. Cytotoxic profiles of normal and cancer cell lines were low and determined by dose and time. Cellular uptake was confirmed by the presence of upconversion luminescence in cell interior. These findings are showing multimodal imaging properties of rod shaped beta-NaGdF4:Yb3+Er3+@PEG-Mo NRs which may be useful in some biomedical applications.

RSC Advances, 6(98), 95633-95643 (2016)

DOI: 10.1039/c6ra20415e   (Pobrane:  2018-04-04)


192.

Pavlenko M., Coy E., Jancelewicz M., Karol Załęski K., Smyntyna V., Jurga S.,Iatsunskyi I.

Enhancement of optical and mechanical properties of Si nanopillars by ALD TiO2 coating The mechanical and optical properties of Si and TiO2-Si nanopillars (NPl) were investigated. Mesoporous silicon NPl arrays were fabricated by metal-assisted chemical etching and nanosphere lithography, and then pillars were covered by TiO2 using the atomic layer deposition technique. We performed scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, reflectance, photoluminescence (PL) spectroscopy and nanoindentation to characterize the as-prepared and annealed TiO2-Si NPl. The main structural and mechanical parameters of TiO2-Si NPl (grain size, strain, critical load, elastic recovery and Young’s module) were calculated. Reflectance and PL spectroscopy were used to study the impact of morphology on optical properties of TiO2-Si NPl before and after annealing. It was established that the nanostructures of TiO2 penetrated inside the porous matrix of Si pillar improve the mechanical properties of TiO2-Si NPl. The results of nanoindentation study have shown that Young’s Modulus of annealed TiO2-Si NPl is about three times higher than for the pure Si NPl.

RSC Advances, 6(99), 97070-97076 (2016)

DOI: 10.1039/c6ra21742g   (Pobrane:  2018-04-03)


191.

Babayevska N., Peplińska B., Jarek M., Yate L., Tadyszak K., Gapiński J., Iatsunskyi I., Jurga S.

Synthesis, structure, EPR studies and up-conversion luminescence of ZnO:Er3+-Yb3+@Gd2O3 nanostructures ZnO:Er3+-Yb3+@Gd2O3 nanostructures were obtained by "wet" chemistry methods - the sol-gel technique for the preparation of ZnO and ZnO:Er3+-Yb3+ nanoparticles (NPs), and the seed deposition method for obtaining Gd2O3. The crystal structure, morphology, phase and elemental composition, resonant microwave absorption of rare earth ions, point defects in the ZnO:Er3+-Yb3+@Gd2O3 crystal structure and up-conversion luminescence were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy, and optical spectroscopy. The crystallization temperature (600 degrees C) of the Gd2O3 phase on the ZnO surface was found. As-obtained ZnO:Er3+-Yb3+ NPs (with size similar to 7 nm) are highly crystalline and monodispersed. ZnO:Er3+-Yb3+ NPs annealing at 900 degrees C leads to the formation of highly polydispersed ZnO:Er3+-Yb3+ NPs, covered by a Gd2O3 shell. The process of the incorporation of the rare earth ions into the ZnO structure, as well as the effect of Gd2O3 content on the morphology and visible up-conversion (UC) luminescence in ZnO:Er3+-Yb3+ matrices were studied.

RSC Advances, 6(92), 89305-89312 (2016)

DOI: 10.1039/c6ra18393j   (Pobrane:  2018-04-04)


190.

Pajzderska A., Drużbicki K., Kiwilsza A., Gonzalez M.A., Jenczyk J., Jurga S., Mielcarek J., Wąsicki J.

On the molecular dynamics in long-acting calcium channel blocker lacidipine: solid-state NMR, neutron scattering and periodic DFT study Molecular and vibrational dynamics of a new-generation lipophilic calcium channel blocker lacidipine (LCDP) are thoroughly explored by combining solid-state nuclear magnetic resonance (NMR) with high-flux quasi-elastic (QENS) and inelastic neutron scattering (INS) experiments. Contrary to the dynamically averaged C-13 CP/MAS NMR response, neutron vibrational spectroscopy confirms our previous findings on the thermodynamically stable structure. High-resolution low-wavenumber INS spectrum is reported and fully interpreted based on periodic density functional theory (DFT) calculations in the quasi-harmonic approximation, staying in excellent agreement with the experiment. The INS spectrum was found to be clearly dominated by CH3 torsional features, widely spread over the range of 5-35 meV. H-1 NMR relaxation indicates a molecular reorientation with different correlation times. The NMR relaxometry was further combined with an extended QENS study, providing a quantitative description of the intramolecular motions in terms of their activation barriers and correlation times, while their assignment was fully supported by theoretical analysis. While the internal dynamics of side-chain methyl groups can be described by rotation about the threefold-axes, the high-resolution QENS measurements give evidence of rotational tunneling of 2,6-methyl groups at low temperature. The vibrational analysis suggests that strong coupling of methyl librations with lattice modes promotes such an intriguing quantum effect.

RSC Advances, 6(71), 66617-66629 (2016)

DOI: 10.1039/c6ra07117a   (Pobrane:  2018-04-04)


189.

Gurzęda B., Florczak P., Wiesner M., Kempiński M., Jurga S., Krawczyk P.

Graphene material prepared by thermal reduction of the electrochemically synthesized graphite oxide In the present work we demonstrate a simple and effective way to produce bulk quantities of graphene material. For the first time, graphite oxide (GO), synthesized by electrochemical treatment of natural graphite in HClO4 aqueous solution, was used to obtain thermally exfoliated-reduced graphite oxide (TRGO). Herein, GO was thermally exfoliated and reduced at 500 degrees C in air, giving the final product of TRGO. Due to shock treatment, the volume of the synthesized TRGO drastically increased compared to the starting GO. Furthermore, the exfoliation process resulted in a significant decrease in the concentration of oxygen functionalities. The choice of GO exfoliation temperature was preceded by thermogravimetric analysis (TGA). TRGO was characterized using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis.

RSC Advances, 6(67), 63058-63063 (2016)

DOI: 10.1039/c6ra10903a   (Pobrane:  2018-04-03)


188.

Pavlenko M., Myndrul V., Iatsunskyi I., Jurga S., Smyntyna V.

Study on structural and optical properties of TiO2 ALD coated silicon nanostructures Structural and optical properties of TiO2 ALD coated silicon nanostructures were investigated. The morphology and chemical composition of TiO2 coated silicon nanopillars and porous silicon were studied by using methods of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Optical characteristics were studied using measurements of reflectance and luminescence spectra. Detailed analysis of morphological features and photoluminescence mechanisms were provided. Peculiarities of reflectance spectra were discussed. It was shown the possible application of these structures as antireflectance coatings.

Proceedings of SPIE - Nanophotonics VI, 9884, 98842H (2016)

DOI: 10.1117/12.2227122
ISBN: 9781510601291   (Pobrane:  2021-01-10)


187.

Baranowska-Korczyc A., Jasiurkowska-Delaporte M., Maciejewska B.M., Warowicka A., Coy L.E., Zalewski T., Kozioł K.K., Jurga S.

PEG-MWCNT/Fe hybrids as multi-modal contrastagents for MRI and optical imaging This study examines the use of oxidized multi-walled carbon nanotube/iron (O-MWCNT/Fe) nanohybrids modified with polyethylene glycol (PEG) as multifunctional cellular imaging agents for magnetic resonance imaging (MRI) and fluorescence microscopy. The PEGylated MWCNTs with embedded iron particles were investigated as T2-weighted contrast agents for MRI. The number of PEG molecules attached to the MWCNT surface was calculated. The PEG-MWCNT/Fe complex was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared and Raman spectroscopies. Covalent surface modification of the MWCNTs improves their solubility and enables the attachment of further biomolecules to their surface. The PEGylated nanostructures were labeled with the MDC organic dye and internalized inside HeLa cells for cellular imaging. Additionally, the minima cytotoxic effect of PEGylated complexes in comparison to non-PEGylated samples was measured Rusing the WST-1 test and an In Cell Analyzer. A confocal microscopy study of the organelle morphology also confi rmed that the HeLa cell morphology was unchanged after treatment with PEGylated MWCs.

RSC Advances, 6(55), 49891-49902 (2016)

DOI: 10.1039/c6ra09191a   (Pobrane:  2018-04-04)


186.

Baranowska-Korczyc A., Warowicka A., Jasiurkowska-Delaporte M., Grześkowiak B., Jarek M., Maciejewska B.M., Jurga-Stopa J., Jurga S.

Antimicrobial electrospun poly(epsilon-caprolactone) scaffolds for gingival fibroblast growth This study discusses the value of polymer electrospun materials in three-dimensional (3D) scaffolds and antibacterial wound dressings for potential dental applications. Polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers were used as bases for gingival fibroblast (HGF-1 cell line) growth. HGF-1 cells cultured on both types of nanofibers were found to have normal morphology and growth by selective staining of the nuclei and cytoskeleton. The nanofibers were synthesized on different collectors to obtain a random or parallel alignment. Cell growth was observed along the nanofibers. In addition, antibiotics were incorporated within the nanofibers and studied by means of Raman spectroscopy and differential scanning calorimetry. The release profile of the antibiotics was determined by broad band dielectric measurements. The drug was found to be released by Fickian diffusion. The WST-1 test found PCL and PCL/ampicillin nanofibers to have minimal cytotoxicity. The antibacterial activity of materials containing ampicillin was evaluated by zone inhibition against a selected oral strain of Streptococcus sanguinis. The bacterial growth was inhibited by antibiotic release from PCL/ampicillin mats.

RSC Advances, 6(24), 19647-19656 (2016)

DOI: 10.1039/c6ra02486f   (Pobrane:  2018-04-03)


185.

Mrówczyński R., Jurga-Stopa J., Markiewicz R., Coy L.E., Jurga S., Woźniak A.

Assessment of polydopamine coated magnetic nanoparticles in doxorubicin delivery Magnetic nanoparticles (MNP) coated with bioinspired polydopamine (PDA) were obtained via a co-precipitation method and oxidative polymerization of dopamine. Nanoparticles were investigated by FTIR, TEM and SQUID. Loading capacity of anticancer drug doxorubicin was determined by UV-Vis spectroscopy. The nanocomposites exhibit a high drug loading capacity of 0.46 mg mg(-1). Anticancer activity of the nanocomposites was proved in profound in vitro tests on HeLa cells. Cytotoxicity and internalization of nanoparticles were checked using various method, i.e. proliferation assay (WST-1), a two-colour fluorescence cell viability assay, and fluorescent and confocal microscopy.

RSC Advances, 6(7), 5936-5943 (2016)

DOI: 10.1039/c5ra24222c


184.

Krysiak E., Wypych-Puszkarz A., Krysiak K., Nowaczyk G., Makrocka-Rydzyk M., Jurga S., Ulański J.

Core-shell system based on titanium dioxide with elevated value of dielectric permittivity: Synthesis and characterization In this work we report a reproducible and efficient method of surface modification of titania nanoparticles (rutile) via reversible-deactivation radical polymerization. Herein, we graft poly(di (ethylene glycol) methyl ether methacrylate) from the surface of TiO2in an amount of 21 wt% within the reaction time of 3 h 15 min. The amount of grafted polymer was assessed by Thermogravimetric Analysis and it is one of the highest reported till now for this ceramic nanoparticles by atom transfer radical polymerization. The properties of inorganic-organic, i.e. core-shell material, as well as of pristine TiO2 and neat polymer were examined by Infrared and Dielectric Spectroscopies. The shape of the nanoparticles and the thickness of the polymer coating shell were investigated by means of High Resolution Transmission Electron Microscopy. The obtained nanocomposite exhibits dielectric permittivity e0= 18 and loss tangent around 1 102 at 20C. The described method allows controlling a length and chemical structure of the grafted polymer from ceramic core, thus to tailor a physical properties of nanoparticles and of nanocomposites.
(C) 2015 Elsevier B.V. All rights reserved.

Synthetic Metals, 209(3), 150-157 (2015)

DOI: 10.1016/j.synthmet.2015.06.028


183.

Maciejewska B.M., Warowicka A., Baranowska-Korczyc A., Zaleski K., Zalewski T., Kozioł K.K., Jurga S.

Magnetic and hydrophilic MWCNT/Fe composites as potential T-2-weighted MRI contrast agents In this work, functionalized Multiwall Carbon Nanotubes of specified length and containing well-defined iron particles (O-MWCNT/Fe) were prepared. A significant enhancement in contrast in Magnetic Resonance Imaging was found for the investigated composites. The magnetic characterization revealed the ferromagnetic nature of iron particles embedded within O-MWCNTs. The enhancement of the H-1 spin-spin relaxation time of MRI scans using hydrophilic O-MWCNT/Fe as potential contrast agents was estimated for selected dispersive media. Moreover, the cytotoxicity of the hybrids was studied in two cell lines, i.e. cancer cells (HeLa) and fibroblasts (GM07492). The intracellular impact of O-MWCNT/Fes in HeLa cells was observed after staining of selected organelles (nuclei and mitochondria). Significant changes in cell morphology were found for water soluble MWCNT/Fes with diameters above 30 nm. (C) 2015 Elsevier Ltd. All rights reserved.

Carbon, 94, 1012-1020 (2015)

DOI: 10.1016/j.carbon.2015.07.091


182.

Michalska M., Aboulaich A., Medjahdi G., Mahiou R., Jurga S., Schneider R.

Amine ligands control of the optical properties and the shape of thermally grown core/shell CuInS2/ZnS quantum dots A series of CuInZnxS2+x QDs has been successfully synthesized via a non-injection method by varying the amine (oleylamine, dioctylamine, dodecylamine, octadecylamine) during the ZnS shell introduction on the CuInS2 core. The effects of these amines on the photoluminescence (PL) and on the morphology of CuInZnxS2+x QDs were explored. The optical features and structure of the obtained CuInZnxS2+x QDs have been characterized by UV visible and fluorescence spectroscopies, time resolved PL, HR-TEM, XRD and EDX. After the ZnS shell introduction at 220 degrees C, CuInZnxS2+x QDs showed greatly improved properties, the PL quantum yield can reach up to 70% using dioctylamine. The formation of CuInZnxS2+x QDs results in a blue shift of both the absorption and PL due to the formation of the alloyed interfacial layer at CuInS2/ZnS during the shell growth. By increasing the reaction temperature to 250 degrees C (thermolysis of CuInZnxS2+x QDs), marked red-shifts in PL emissions accompanied by morphological changes of the nanocrystals were observed. The use of oleylamine generates 6.6 nm-sized pyramidally-shaped nanocrystals with a PL quantum yield of 22%.
(C) 2015 Elsevier B.V. All rights reserved.

Journal of Alloys and Compunds, 645, 184-192 (2015)

DOI: 10.1016/j.jallcom.2015.04.162


181.

Makrocka-Rydzyk M., Woźniak-Braszak A., Jurga K., Jurga S.

Local motions in poly(ethylene-co-norbornene) studied by 1H NMR relaxometry Molecular motions in poly(ethylene-co-norbornene) were studied in a temperature range well below its glass transition point by a few techniques based on the NMR phenomenon. Temperature dependencies of proton spin-lattice relaxation times T1 (at 200 MHz and at 30.2 MHz), proton spin-lattice relaxation time in the rotating frame T1ρ (at 68 kHz) and frequency dispersion of proton spin-lattice off-resonance relaxation times in the rotating frame View the MathML source were determined for the copolymer. Analysis of 1H NMR relaxation data permitted characterization of local motions occurring in the copolymer i.e. rotation of methyl groups around C3 axes, reorientations of methylene groups and motions of segments of polymer chains including norbornene groups.

Solid State Nuclear Magnetic Resonance, 71, 67-72 (2015)

DOI: 10.1016/j.ssnmr.2015.08.005


180.

Ivashchenko O., Lewandowski M., Peplińska B., Jarek M., Nowaczyk G., Wiesner M., Zaleski K., Babutina T., Warowicka A., Jurga S.

Synthesis and characterization of magnetite/silver/antibiotic nanocomposites for targeted antimicrobial therapy The article is devoted to preparation and characterization of magnetite/silver/antibiotic nanocomposites for targeted antimicrobial therapy. Magnetite nanopowder was produced by thermochemical technique; silver was deposited on the magnetite nanoparticles in the form of silver clusters. Magnetite/silver nanocomposite was investigated by XRD, SEM, TEM, AFM, XPS, EDX techniques. Adsorptivity of magnetite/silver nanocomposite towards seven antibiotics from five different groups was investigated. It was shown that rifampicin, doxycycline, ceftriaxone, cefotaxime and doxycycline may be attached by physical adsorption to magnetite/silver nanocomposite. Electrostatic surfaces of antibiotics were modeled and possible mechanism of antibiotic attachment is considered in this article. Raman spectra of magnetite, magnetite/silver and magnetite/silver/antibiotic were collected. It was found that it is difficult to detect the bands related to antibiotics in the magnetite/silver/antibiotic nanocomposite spectra due to their overlap by the broad carbon bands of magnetite nanopowder. Magnetic measurements revealed that magnetic saturation of the magnetite/silver/antibiotic nanocomposites decreased on 6-19% in comparison with initial magnetite nanopowder. Pilot study of antimicrobial properties of the magnetite/silver/antibiotic nanocomposites were performed towards Bacillus pumilus.
© 2015 Elsevier B.V. All rights reserved.

Materials Science & Engineering C - Materials for Biological Applications, 55, 343-359 (2015)

DOI: 10.1016/j.msec.2015.05.023   (Pobrane:  2018-03-29)


179.

Lewandowski M., Miłosz Z., Michalak N., Ranecki R., Sveklo I., Kurant Z., Maziewski A., Mielcarek S., Luciński T., Jurga S.

Room temperature magnetism of few-nanometers-thick Fe3O4(111) films on Pt(111) and Ru(0001) studied in ambient conditions Few-nanometers-thick Fe3O4(111) filmswere epitaxially grown on Pt(111) and Ru(0001) single crystal supports by sequential iron deposition and oxidation in an ultra-high vacuum chamber. The growth of well-ordered magnetite films was confirmed by low energy electron diffraction. The films were covered with a protective Au layer and subjected to magnetic and structural studies in ambient conditions. Magnetic hysteresis loops, recorded using magneto-optical Kerr effect apparatus, confirmed magnetic ordering in both films at room temperature. The Kerr measurements indicated in-plane orientation of magnetization, which was supported by the lack of magnetic contrast in magnetic force microscopy images. Atomic force microscopy revealed significant differences in morphology of the films, tentatively attributed to different lattice mismatch with Pt(111) and Ru(0001) single crystal supports. (C) 2015 Elsevier B.V. All rights reserved.

Thin Solid Films, 591(B), 285-288 (2015)

DOI: 10.1016/j.tsf.2015.04.060


178.

Bartkowiak G., Gawron K., Jurga S., Schroeder G.

Mass spectrometry of lanthanide(III) complexes with 2,6-diformylpyridine bis(4-pyridylcarbohydrazone) and its unusual methylation observed in matrix-assisted laser desorption/ionization mass spectra Mass spectrometry of lanthanide(III) complexes with2,6-diformylpyridine bis(4-pyridylcarbohydrazone) and itsunusual methylation observed in matrix-assisted laserdesorption/ionization mass spectra.

Rapid Communications in Mass Spectrometry, 29(18), 1696-1702 (2015)

DOI: 10.1002/rcm.7260   (Pobrane:  2018-04-04)


177.

Cho H.Y., Krys P, Szcześniak K., Schroeder H., Park S., Jurga S., Buback M., Matyjaszewski K.

Synthesis of poly(OEOMA) using macromonomers via "grafting-through" ATRP Atom transfer radical polymerization (ATRP) of oligo(ethylene oxide) methyl ether methacrylate (OEOMA, M-n = 950 or 2080; OEOMA is also termed poly(ethylene glycol) methyl ether methacrylate, PEGMA) macromonomers was investigated as a function of initial monomer concentration, [OEOMA](0), ranging from 50 to 300 mM, and up to 4.5 kbar. Polymerizations were successfully carried out in organic solvents with [OEOMA](0) > 75 mM, whereas with [OEOMA](0) = 50 mM no monomer conversion was observed at ambient pressure, indicating that the macromonomer concentration was below its equilibrium monomer concentration ([M](e)). High pressure reduced [M](e) to a level lower than under ambient pressure, allowing polymerization at [OEOMA](0) = 50 mM up to high monomer conversion and yielding polymers with narrow molecular weight distribution. By varying the targeted degree of polymerization of OEOMA, brushlike or starlike poly(OEOMA) were prepared under both ambient and high pressure.

Macromolecules, 48(18), 6385-6395 (2015)

DOI: 10.1021/acs.macromol.5b01592   (Pobrane:  2018-03-29)


176.

Iatsunskyi I., Coy E., Viter R., Nowaczyk G., Jancelewicz M., Baleviciute I., Załęski K., Jurga S.

Study on structural, mechanical and optical properties of Al2O3-TiO2 nanolaminates prepared by atomic layer deposition Structural, optical, and mechanical properties of Al2O3/TiO2 nanolaminates fabricated by atomic layer deposition (ALD) were investigated. We performed transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray reflectivity (XRR), energy dispersive X-ray spectroscopy (EDX), ellipsometry, UV-vis spectroscopy, photoluminescence (PL) spectroscopy, and nanointendation to characterize the Al2O3/TiO2 nanolaminates. The main structural, optical, and mechanical parameters of Al2O3/TiO2 nanolaminates (thickness, grain size, refractive index, extinction coefficient, band gap, hardness, and Young’s module) were calculated. It was established that with decreasing of the layer thickness, the value of band gap energy increases due to the quantum size effect related to the reduction of the nanograins size. On the other hand, the decreasing of nanograins size leads to generation of interface defects and, as a consequence, to the increasing of Urbach energy. It was also shown that there is an interdiffusion layer at the Al2O3-TiO2 interface, which plays a crucial role in explaining mechanical and optical properties of Al2O3/TiO2 nanolaminates. The correlation between structural, optical, and mechanical parameters was discussed.

Journal of Physical Chemistry C, 119(35), 20591-20599 (2015)

DOI: 10.1021/acs.jpcc.5b06745


175.

Iatsunskyi I., Jancelewicz M., Nowaczyk G., Kempiński M., Peplińska B., Jarek M., Załęski K., Jurga S., Smyntyna V.

Atomic layer deposition TiO2 coated porous silicon surface: Structural characterization and morphological features TiO2 thin films were grown on highly-doped p-Si (100) macro- and mesoporous structures by atomic layer deposition (ALD) using TiCl4 and deionized water as precursors at 300 °C. The crystalline structure, chemical composition, and morphology of the deposited films and initial silicon nanostructures were investigated by scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy and X-ray diffraction (XRD). The mean size of TiO2 crystallites was determined by TEM, XRD and Raman spectroscopy. It was shown that the mean crystallite size and the crystallinity of the TiO2 are influenced dramatically by the morphology of the porous silicon, with the mesoporous silicon resulting in a much finer grain size and amorphous structure than the macroporous silicon having a partially crystal anatase phase. A simple model of the ALD layer growth inside the pores was presented.

Thin Solid Films , 589, 303-308 (2015)

DOI: 10.1016/j.tsf.2015.05.056


174.

Iatsunskyi I., Kempinski M., Nowaczyk G., Jancelewicz M., Pavlenko M., Zaleski K., Jurga S.

Structural and XPS studies of PSi/TiO2 nanocomposites prepared by ALD and Ag-assisted chemical etching PSi/TiO2 nanocomposites fabricated by atomic layer deposition (ALD) and metal-assisted chemical etching (MACE) were investigated. The morphology and phase structure of PSi/TiO2 nanocomposites were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) with an energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. The mean size of TiO2 nanocrystals was determined by TEM and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior of the Ti 2p, 0 1s and Si 2p lines. TEM, Raman spectroscopy and XPS binding energy analysis confirmed the formation of TiO2 anatase phase inside the PSi matrix. The XPS valence band analysis was performed in order to investigate the modification of PSi/TiO2 nanocomposites electronic structure. Surface defects states of Ti3+ at PSi/TiO2 nanocomposites were identified by analyzing of XPS valence band spectra.
(C) 2015 Elsevier B.V. All rights reserved.

Applied Surface Science, 347, 777-783 (2015)

DOI: 10.1016/j.apsusc.2015.04.172


173.

Choudhury A.R., Sikorska E., van den Boom J., Bayer P., Popenda Ł., Szutkowski K., Jurga S., Bonomi M., Sali A., Zhukov I., Passamonti S., Novic M.

Structural model of the bilitranslocase transmembrane domain supported by NMR and FRET data We present a 3D model of the four transmembrane (TM) helical regions of bilitranslocase (BTL), a structurally uncharacterized protein that transports organic anions across the cell membrane. The model was computed by considering helix-helix interactions as primary constraints, using Monte Carlo simulations. The interactions between the TM2 and TM3 segments have been confirmed by Forster resonance energy transfer (FRET) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy, increasing our confidence in the model. Several insights into the BTL transport mechanism were obtained by analyzing the model. For example, the observed cis-trans Leu-Pro peptide bond isomerization in the TM3 fragment may indicate a key conformational change during anion transport by BTL. Our structural model of BTL may facilitate further studies, including drug discovery.

PloS ONE, 10(8), e0135455 (2015)

DOI: 10.1371/journal.pone.0135455   (Pobrane:  2020-10-23)


172.

Mrówczyński R., Coy L.E., Scheibe B., Czechowski T., Augustyniak-Jabłokow M., Jurga S., Tadyszak K.

Electron paramagnetic resonance imaging and spectroscopy of polydopamine radicals A thorough investigation of biomimetic polydopamine (PDA) by Electron Paramagnetic Resonance (EPR) is shown. In addition, temperature dependent spectroscopic EPR data are presented in the range 3.8-300 K. Small discrepancies in magnetic susceptibility behavior are observed between previously reported melanin samples. These variations were attributed to thermally acitivated processes. More importantly, EPR spatial spatial 2D imaging of polydopamine radicals on a phantom is presented for the first time. In consequence, a new possible application of polydopamine as EPR imagining marker is addressed.

The Journal of Physical Chemistry B, 119(32), 10341-10347 (2015)

DOI: 10.1021/acs.jpcb.5b01524   (Pobrane:  2018-03-29)


171.

Sokół B., Woźniak A., Jankowski R., Jurga S., Wąsik N., Shahid H., Grześkowiak B.

HMGB1 level in cerebrospinal fluid as a marker of treatment outcome in patients with acute hydrocephalus following Aneurysmal Subarachnoid Hemorrhage Background: Attempts to clarify mechanisms of early brain injury in subarachnoid hemorrhage (SAH) revealed a high-mobility group box 1 (HMGB1) protein involvement in sterile inflammation initiated by aneurysm rupture. This study aims at assessing the prognostic value of HMGB1 in comparison with traditional biomarkers. Methods: Ten patients with Fisher grade 4 SAH and acute hydrocephalus underwent endovascular coiling and ventriculostomy. HMGB1 level was measured in cerebrospinal fluid (CSF) samples collected on first, fifth, and 10th day. HMGB1 level in first sample was correlated with treatment outcome assessed in Glasgow outcome scale (GOS) at 3 months. Obtained results were compared with plasma inflammatory markers, clinical grading scales, and imaging grading scales. HMGB1 level in consecutive samples was analyzed in search of concentration trends correlating with patients' outcome. Results: HMGB1 level in CSF of SAH patients, in contrast to control group, is significantly elevated (P < .001). Good (GOS > 3) and poor (GOS <= 3) outcome patients differ significantly in HMGB1 level on admission (P < .01). The strongest correlation to patients' outcome was found for Hunt and Hess scale (R = -.887, P < .01), HMGB1 level (R = -.859, P < .01), and World Federation of Neurological Surgeons scale (R = -.832, P < .01). Constant and high HMGB1 level of 10 ng/mL or more in consecutive CSF samples identifies non-survivors. Conclusions: HMGB1 protein is elevated in SAH patients. Changes in the concentration of HMGB1 in consecutive samples of the CSF correlate with outcome. Our results encourage further proteomic investigation.
(C) 2015 by National Stroke Association

Journal of Stroke & Cerebrovascular Diseases, 24(8), 1897-1904 (2015)

DOI: 10.1016/j.jstrokecerebrovasdis.2015.05.002


170.

Matczak M., Schafer R., Urbaniak M., Szymański B., Kuswik P., Jarosz A., Schmidt M., Aleksiejew J., Jurga S., Stobiecki F.

Domain wall generated by graded interlayer coupling in Co/Pt/Co film with perpendicular anisotropy A magnetic multilayer of the structure substrate/Pt-15 nm/Co-0.8 nm/Pt-wedge(0-7 nm)/Co-0.6 nm/ Pt-2 nm is characterized by perpendicular anisotropy of both Co layers. For a Pt spacer thickness t(Pt) <= 2.6 nm, the magnetization reversal of the Co-layers occurs cooperatively, while for larger t(Pt), it occurs sequentially. The Co-layer with 0.6 nm thickness (Co-S) is magnetically softer than the second one (Co-H). In the 2.6 <= t(Pt) <= 3.0 nm range, there are significant changes of the switching field due to a strong gradient of the interlayer coupling. In this region, the magnetization reversal in the Co-S layer takes place reversibly by the propagation of a single, straight domain wall. This specific nature of magnetization reversal is explained by a decelerated motion of the domain wall observed both for the direction corresponding to the increasing, as well as decreasing coupling energy.

Applied Physics Letters, 107(1), 012404 (2015)

DOI: 10.1063/1.4926357   (Pobrane:  2018-03-29)


169.

Gierszewski M., Falkowski M., Sobotta L., Stolarska M., Popenda Ł., Lijewski S., Wicher B., Burdzinski G., Karolczak J., Jurga S., Gdaniec M., Tykarska E., Sikorski M., Mielcarek J., Gośliński T.

Porphyrazines with peripheral isophthaloxyalkylsulfanyl substituents and their optical properties Porphyrazines possessing isophthaloxyalkylsulfanyl substituents in the periphery were synthesized and subjected to various photophysical studies, including optical absorption and emission measurements. The fluorescence lifetimes of four porphyrazine derivatives were measured in different organic solvents. The results of the steady-state and time-resolved measurements of magnesium porphyrazines with different alkyl groups between sulfanyl substituent and isophthaloxy group were compared with those of demetallated porphyrazine. The porphyrazine macrocycles exhibit interesting solvatochromic effects, which are described by Delta f solvent polarity scale and four-parameter scale proposed by Catalan. Transient absorption spectroscopy was used to obtain the values of triplet lifetime for magnesium porphyrazine with 2-(3,5-dibutoxycarbonylphenoxy)ethylsulfanyl substituents. Values of singlet oxygen generation quantum yields were obtained in different organic solvents using various techniques, including the characteristic emission of the singlet oxygen at 1270 nm with the steady-state and time-resolved approaches.
(C) 2015 Elsevier B.V. All rights reserved.

Journal of Photochemistry and Photobiology A : Chemistry, 307-308, 54-67 (2015)

DOI: 10.1016/j.jphotochem.2015.04.003   (Pobrane:  2018-03-29)


168.

Gierszewski M., Falkowski M., Sobotta Ł., Stolarska M.,Popenda Ł., Lijewski S., Wicher B., Burdzinski G., Karolczak J., Jurga S., Gdaniec M., Tykarska E., Sikorski M., Mielcarek J., Goślinski T.

Cambridge Structural Database, , (2015)

DOI: 10.5517/cc1435n2
DBR: http://dx.doi.org/10.5517/cc1435n2   (Pobrane:  2021-01-07)


167.

Rębiś T., Lijewski S., Nowicka J., Popenda Ł., Sobotta Ł., Jurga S., Mielcarek J., Milczarek G., Gośliński T.

Electrochemical properties of metallated porphyrazines possessing isophthaloxybutylsulfanyl substituents: Application in the electrocatalytic oxidation of hydrazine The demetallation reaction of sulfanyl magnesium(II) porphyrazine with isophthaloxybutyl substituents, accompanied by remetallation with zinc(II) and cobalt(II) salts, leads to the corresponding zinc(II) and cobalt(II) derivatives in moderate yields. All porphyrazines were analyzed by HPLC and characterized by UV-vis, MS and various NMR techniques (H-1-H-1 COSY, H-1-C-13 HSQC, H-1-C-13 HMBC). Voltammetric experiments conducted in dichloromethane solution showed that the novel porphyrazine complexes exhibit promising electrochemical properties. For all complexes one electron transfer process was observed in the studied potential range. Cobalt(II) porphyrazine revealed metal-involved redox couple at -0.79 V vs Fc/Fc(+), as well as peaks derived from ligand reduction/oxidation. Zinc(II) and demetalled porphyrazines showed well-defined macrocycle-based electron transfer processes. A glassy carbon electrode modified by carbon nanotubes/cobalt(II) porphyrazine - composite exhibited great electro-catalytic ability towards the oxidation of hydrazine. A combination of porphyrazine and carbon nanotubes makes it possible to obtain a synergistic effect that increased the rate of hydrazine oxidation. A significant decrease in the overpotential, compared to that obtained through glassy carbon electrode/cobalt( II) porphyrazine or glassy carbon electrode/carbon nanotubes, allows for sensitive determination of hydrazine in neutral conditions (pH 7.4). The novel cobalt(II) porphyrazine macrocycle seems to be a promising material for the design of novel amperometric sensors and electrocatalysts.
(C) 2015 Elsevier Ltd. All rights reserved.

Electrochimica Acta, 168, 216-224 (2015)

DOI: 10.1016/j.electacta.2015.03.191


166.

Lewandowski M., Michalak N., Miłosz Z., Ranecki R., Luciński T., Jurga S.

Structure of Fe3O4(111) films on Pt(111) and Ru(0001): The role of epitaxial strain at the iron oxide/metal single crystal interface Thin oxide films epitaxially grown on metal single crystal surfaces may exhibit structural properties that differ from the corresponding bulk oxide materials. The structure of the films is often rendered by their thickness, the structure and properties of the substrate and by the nature of the oxide/substrate interface. We prepared thin iron oxide films on Pt(111) and Ru(0001) and studied their structure using STM, LEED and XPS. The structure of FeO(111) - the iron oxide phase that forms at the interface with the metal single crystal - depends on the parameters of the support and is believed to further influence the structure of thicker iron oxide films, such as Fe3O4(111), that are being grown on top of it. In this article we discuss the role of one of the important parameters that may determine this structure - the epitaxial strain at the iron oxide/metal single crystal interface.

Nanoscience Advances in CBRN Agents Detection, Information and Energy Security, Petkov P., Tsiulyanu D., Kulisch W., Popov C. (Eds.), , 319-324 (2015)

DOI: 10.1007/978-94-017-9697-2_32
ISBN: 978-94-017-9696-5   (Pobrane:  2021-01-10)


165.

Trzaskowska A., Mielcarek S., Lewandowski M., Miłosz Z., Michalak N., Ranecki R., Coy L.E., Jarek M., Luciński T., Jurga S.

Brillouin spectroscopy and finite element method study of surface acoustic wave propagation in clean and Fe3O4(111) covered Pt(111) and Ru(0001) single crystals Brillouin light scattering was used to study surface acoustic wave propagation in platinum (111) and ruthenium (0001) single crystals, both clean and loaded with a few-nanometre-thick epitaxial magnetite (111) film. The results revealed the influence of the film loading on the velocity of surface acoustic wave propagation in the studied samples. The surface acoustic modes were additionally analysed by finite element method simulations.
(C) 2015 Elsevier B.V. All rights reserved.

Surface and Coating Technology, 271, 13-17 (2015)

DOI: 10.1016/j.surfcoat.2015.01.055   (Pobrane:  2018-04-04)


164.

Lewandowski M., Scheibe B., Vasileiadis Th., Michalak N., Miłosz Z., Ranecki R., S. Mielcarek S., Luciński T., Jurga S.

Raman spectroscopy indications of the Verwey transition in epitaxial Fe3O4(111) films on Pt(111) and Ru(0001) Temperature-dependent Raman spectroscopy was used for studying few-nanometers-thick epitaxial Fe3O4(111) films grown on Pt(111) and Ru(0001) single crystal supports. The changes in position, intensity and full width at half maximum of the magnetite's A(1g) peak, corresponding to symmetric stretching of oxygen atoms along Fe-O bonds, were monitored in temperatures ranging from 300 to 80 K. The results gave indications of the presence of the Verwey transition in magnetite films on both supports.
(C) 2015 Elsevier B.V. All rights reserved.

Surface and Coating Technology, 271, 87-91 (2015)

DOI: 10.1016/j.surfcoat.2015.01.008   (Pobrane:  2018-04-04)


163.

Iatsunskyi I., Pavlenko M., Viter R., Jancelewicz M., Nowaczyk G., Baleviciute I., Załęski K., Jurga S., Ramanavicius A., Smyntyna V.

Tailoring the structural, optical, and photoluminescence properties of porous silicon/TiO2 nanostructures The structural, optical, and photoluminescence properties of porous silicon (PSi)/titanium dioxide (TiO2) nanostructures were investigated. PSi structures consisting of macro- and mesoporous layers were fabricated by metal-assisted chemical etching, and then TiO2 was introduced inside the PSi matrix using the atomic layer deposition technique. We performed scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, energy dispersive X-ray spectroscopy, Raman spectroscopy, ellipsometry, and photoluminescence (PL) spectroscopy to characterize the prepared and annealed PSi/TiO2 nanostructures. TEM and Raman analyses revealed that TiO2 had a crystalline anatase structure. PL measurements of the PSi/TiO2 composite system showed two broad peaks at approximately 2.4-3 eV (blue PL) and 1.7-1.9 eV (red PL). The mechanisms of the emissions were discussed, and it was found that two main competing recombination mechanisms take place, including radiative recombination through the surface states (surface recombination) and through oxygen vacancies and self-trapped excitons (volume recombination).

Journal of Physical Chemistry C, 119(13), 7164-7171 (2015)

DOI: 10.1021/acs.jpcc.5b01670


162.

Vasylenko A.I., Tokarchuk M.V., Jurga S.

Effect of a vacancy in single-walled carbon nanotubes on He and NO adsorption In a theoretical study of gas adsorption on carbon nanotubes (CNTs), we conduct a series of ab initio simulations for a gas-single-wall carbon nanotube system for gases of particular practical interest: He and NO. The obtained values of adsorption energy reveal preferable localization sites of absorbed He atoms as well as their dependency on the adsorption distances. A significant effect of NO adsorption on CNT electronic properties is demonstrated. The effect of the presence of a vacancy on the adsorption nature is analyzed. It is shown that under the influence of vacancy formation the CNT structure undergoes reconstruction that enables chemisorption of NO molecules.

Journal of Physical Chemistry C, 119(9), 5113-5116 (2015)

DOI: 10.1021/jp511532j


161.

Woźniak-Braszak A., Jurga K., Nowaczyk G., Dobies M., Szostak M., Jurga J., Jurga S.

Characterization of poly(ethylene 2,6-naphthalate)/polycarbonate blends by DSC, NMR off-resonance and DMTA methods The poly(ethylene 2,6-naphthalate) (PEN)/polycarbonate (PC) blends with the weight ratio of homopolymers 50/50 wt./wt. were prepared by injection molding using the Engel machine ES. One mixture was synthesized without the compatibilizer and the second with the compatibilizer SMAC (Samarium acetylacetonate hydrate). The influence of the cornpatibilizer on the physical and mechanical properties of the PEN/PC blends was investigated. The thermal properties of the new synthesized blends were studied by the differential scanning calorimetry (DSC). The molecular dynamics of the polymer blends was studied by the off-resonance NMR. The correlation times of the internal motions and the spectral density function amplitudes were estimated on the basis of the dispersion of the spin lattice relaxation time T1ρ(off) in the rotating frame off-resonance. The rheological properties of the studied blends were investigated by dynamic mechanical thermal analysis (DMTA). The temperature dependencies of the storage modulus G', of the loss modulus G" and of the loss tangent (tan δ) were analyzed in order to evaluate the relaxation processes in the studied systems. The analysis of the DMTA data revealed the existence of two primary (α(1) and α(2)) and two secondary (β and γ) relaxation processes in the blend of PEN/PC 50/50 wt./wt. and one primary (α) and two secondary (β and γ) relaxation processes in the blend of PEN/PC 50/50 wt./wt with the compatibilizer. The motional parameters for the above - mentioned relaxation processes were calculated using the Havriliak Negami formalism. The comparative analysis of the DSC, NMR off-resonance and DMTA results led to the clarification of the molecular motion in the PEN/PC 50/50 wt./wt. blends.
(C) 2015 Elsevier Ltd. All rights reserved.

European Polymer Journal, 64, 62-69 (2015)

DOI: 10.1016/j.eurpolymj.2014.12.039   (Pobrane:  2020-10-23)


160.

Iatsunskyi I., Kempiński M., Jancelewicz M., Załęski K., Jurga S., Smyntyna V.

Structural and XPS characterization of ALD Al2O3 coated porous silicon Al2O3 thin films were grown on highly-doped p-Si (100) macro- and mesoporous structures by atomic layer deposition (ALD) using trimethylaluminum (TMA) and water H2O as precursors at 300 degrees C. The porous silicon (PSi) samples were fabricated utilizing a metal-assisted chemical etching process (MACE). The morphology of the deposited films and initial silicon nanostructures were investigated by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior of the Al 2p, O 1s and C 1s lines. Calculated Auger parameter and binding energy analysis confirmed Al2O3 formation. The measurement of band gap energies of Al2O3 was performed.
(C) 2014 Elsevier Ltd. All rights reserved.

Vacuum, 13, 52-58 (2015)

DOI: 10.1016/j.vacuum.2014.12.015   (Pobrane:  2019-10-15)


159.

Erdmann V.A., Jurga S., Barciszewski J.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

RNA and DNA diagnostics preface The aim of molecular diagnostics is preferentially to detect a developing disease before any symptoms appear. There has been a significant increase, fueled by technologies from the human genome project, in the availability of nucleic acid sequence information for all living organisms including bacteria and viruses. When combined with a different type of instrumentation applied, the resulting diagnostics is specific and sensitive. Nucleic acid-based medical diagnosis detects specific DNAs or RNAs from the infecting organism or virus and a specific gene or the expression of a gene associated with a disease. Nucleic acid approaches also stimulate a basic science by opening lines of inquiry that will lead to greater understanding of the molecules at the center of life. One can follow Richard Feynman’s famous statement “What I cannot create, I do not understand.”

Book Series: RNA Technologies, Erdmann V.A., Jurga S., Barciszewski J. (Eds.), , V-VII, Springer-Verlag Berlin, Heidelberger Platz 3, d-14197 Berlin, Germany (2015)

DOI: 10.1007/978-3-319-17305-4
ISBN: 978-3-319-17304-7   (Pobrane:  2018-03-28)


158.

Iatsunskyi I., Nowaczyk G., Jurga S., Fedorenko V., Pavlenko M., Smyntyna V.

One and two-phonon Raman scattering from nanostructured silicon Raman scattering from highly/low resistive nanostructured silicon films prepared by metal-assisted chemical etching was investigated. Raman spectrum of obtained silicon nanostructures was measured. Interpretation of observed one and two-phonon Raman peaks are presented. First-order Raman peak has a redshift and broadening. This phenomenon is analyzed in the framework of the phonon confinement model taking into account mechanical stress effects. Second-order Raman peaks were found to be shifted and broadened in comparison to those in the bulk silicon. The peak shift and broadening of two-phonon Raman scattering relates to phonon confinement and disorder. A broad Raman peak between 900 and 1100 cm(-1) corresponds to superposition of three transverse optical phonons similar to 2TO (X), 2TO (W) and 2TO (L). Influence of excitation wavelength on intensity redistribution of two-phonon Raman scattering components (2TO) is demonstrated and preliminary theoretical explanation of this observation is presented. (C) 2015 Elsevier GmbH. All rights reserved.

Optik, 126(18), 1650-1655 (2015)

DOI: 10.1016/j.ijleo.2015.05.088   (Pobrane:  2018-03-29)


157.

Flak D., Coy E., Nowaczyk G., Yate L., Jurga S.

Tuning the photodynamic efficiency of TiO2 nanotubes against HeLa cancer cells by Fe-doping In this study Fe-doped TiO2 (0.35 to 3.50 wt% Fe) nanotubes (NTs) were prepared as the potential photosensitizer for near-visible light driven photodynamic therapy (PDT) against cervical cancer cells (HeLa). Characterization of the prepared nanotubes by X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the successful incorporation of Fe3+ as a dopant into the TiO2 matrix, which was mainly composed of an anatase phase, while elemental mapping using energy dispersive X-ray spectroscopy (EDX) showed homogenous distribution of the dopant ions in TiO2 for both low and high doping levels. UV-Vis studies showed that Fe doping in TiO2 increases the light absorption within the visible range, particularly in the case of 0.70 and 1.40 wt% Fe-TiO2 and provides additional energy levels within the band gap, which promotes the photo-excited charge transport towards the conduction band. Photo-cytotoxic activity of the prepared Fe-doped TiO2 NTs was investigated in vitro against cervical cancer cells (HeLa) and compared with human normal fibroblasts (GM07492). Fe-doped TiO2 NTs exhibited no or lower dark cytotoxicity than un-doped TiO2 NTs, which confirms their superior biocompatibility. Under the near-visible light irradiation (similar to 405 nm) Fe-doped TiO2 NTs showed higher photo-cytotoxic efficiency than un-doped TiO2 NTs, which was found to be dependent on the NTs concentration, but not on the incubation time of cells after near-visible light irradiation. The highest activity was observed for 0.70 and 1.40 wt% Fe-TiO2 NTs. Fluorescent labeling of treated HeLa cells showed distinct morphological changes, particularly in the perimitochondrial area suggesting a mitochondria-involved apoptosis of cells, but also the nuclei and cytoskeleton were subject to Fe-TiO2 NTs induced photo-damage. Apoptosis of PDT treated HeLa cells was also confirmed using ethidium homodimer (EthD-1).

RSC Advances, 5(103), 85139-85152 (2015)

DOI: 10.1039/c5ra17430a   (Pobrane:  2018-04-04)


156.

Szatkowski T., Wysokowski M., Lota G., Pęziak D., Bazhenov V.V., Nowaczyk G., Walter J., Molodtsov S.L., Stocker H., Himcinschi C., Petrenko L., Stelling A.L., Jurga S., Jesionowski T. Ehrlich H.

Novel nanostructured hematite-spongin composite developed using an extreme biomimetic approach The marine sponge Hippospongia communis (Demospongiae: Porifera) is a representative of bath sponges, which possess characteristic mineral-free fibrous skeletons made of a structural protein - spongin. This fibrous skeleton is mechanically robust, resistant to acidic treatment, and thermally stable up to 160 degrees C. Due to these properties, we decided to use this biological material for the first time for the hydrothermal synthesis of hematite (alpha-Fe2O3) via catalyzed hydrolysis of FeCl3 to obtain a hematite-spongin composite. The material obtained was studied with Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), X-ray Photoemission Spectroscopy (XPS) and Raman spectroscopy. The alpha-Fe2O3-spongin-based composite was tested for its potential application as an anode material in a capacitor. The results indicate that components constructed using this novel composite material have a positive effect on the capacitance of energy storing devices.

RSC Advances, 5(96), 79031-79040 (2015)

DOI: 10.1039/c5ra09379a   (Pobrane:  2018-04-04)


155.

Bartkowiak G., Popenda Ł., Jurga S., Schroeder G.

Synthesis and NMR and mass spectrometric study of ammonioacetohydrazones of formylphenylboronic acids as novel ionic prospective sugar receptors Novel sugar-sensing, soluble in aqueous media, boronic acid derivatives designed for easy analysis through MALDI mass spectrometry have been synthesized in a high yield through a mild and efficient procedure. The synthesized compounds are based on formylphenylboronic acids, which can bind through the formyl group with acid hydrazides to form the respective hydrazones. As hydrazide substrates, Girard reagents T and P were chosen, which possess precharged ammonium and pyridinium moieties, respectively. Nuclear magnetic resonance spectroscopy (H-1, C-13, HSQC, HMBC, and NOESY) and mass spectrometry were employed to study their structure, conformational equilibrium and interaction with selected sugars and other diols. Our study shows that the ammonioacetohydrazones of formylphenylboronic acids are present in DMSO solution in the form of cis/trans amide conformers and the effectiveness of their interaction with sugars depends on the situation of the substituent in relation to the boronic acid group. Introducing an ionic group to the receptor molecule improves the sensitivity for conjugate detection when analyzed by MS with matrix-assisted laser desorption/ionization (MALDI) in the positive-ion mode.

New Journal of Chemistry, 39(6), 4695-4707 (2015)

DOI: 10.1039/c4nj02103g   (Pobrane:  2018-04-04)


154.

Maciejewska B.M., Coy L.E., Koziol K.K.K., Jurga S.

Facile synthesis of highly stable and water-soluble magnetic MWCNT/alpha-Fe nanocomposites Multiwall carbon nanotubes (MWCNT) were synthesized by the floating catalyst chemical vapor deposition (FCCVD) method. As a result, nanotubes containing metallic iron (a-Fe) were obtained and characterized. The impact of surface modification, on MWCNTs stability in water, was thoroughly studied applying three oxidative protocols. Samples were further characterized and correlated based on scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA), and the magnetic nature of the embedded nanoparticles was assessed by means of a SQUID magnetometer at room temperature in powder. Finally, precise length segregation of MWCNT/alpha-Fe nanocomposites was achieved. The studied structures showed excellent quality and unmatched stability in water after more than three months.

The Journal of Physical Chemistry C, 118(4), 27861-27869 (2014)

DOI: 10.1021/jp5077142


153.

Szczeszak A., Grzyb T., Śniadecki Z., Andrzejewska N., Lis S., Matczak M., Nowaczyk G., Jurga S., Idzikowski B.

Structural, spectroscopic and magnetic properties of Eu3+ - doped GdVO4 nanocrystals synthesized by a hydrothermal method New interesting aspects of the spectroscopic properties, magnetism, and method of synthesis of gadolinium orthovanadates doped with Eu3+ ions are discussed. Gd-1-xEuxVO(4) (x = 0, 0.05, 0.2) bifunctional luminescent materials with complex magnetic properties were synthesized by a microwave-assisted hydrothermal method. Products were formed in situ without previous precipitation. The crystal structures and morphologies of the obtained nanomaterials were analyzed by X-ray diffraction and transmission and scanning electron microscopy. Crystallographic data were analyzed using Rietveld refinement. The products obtained were nanocrystalline with average grain sizes of 70-80 nm. The qualitative and quantitative elemental composition as well as mapping of the nanocrystals was proved using energy-dispersive X-ray spectroscopy. The spectroscopic properties of red-emitting nanophosphors were characterized by their excitation and emission spectra and luminescence decays. Magnetic measurements were performed by means of vibrating sample magnetometry. GdVO4 and Gd0.8Eu0.2VO4 exhibited paramagnetic behavior with a weak influence of antiferromagnetic couplings between rare-earth ions. In the substituted sample, an additional magnetic contribution connected with the population of low-lying excited states of europium was observed.

Inorganic Chemistry, 53(23), 12243-12252 (2014)

DOI: 10.1021/ic500354t


152.

Wencka M., Hahne M., Kocjan A., Vrtnik S., Kozelj P., Korze D., Jaglicic Z., Soric M., Poptevic P., Ivkov J., Smontara A., Gille P., Jurga S., Tomes P., Paschen S., Ormeci A., Armbruster M., Grin Yu., Dolinsek J.

Physical properties of the InPd intermetallic catalyst The intermetallic phase InPd is a candidate material for the use as a catalyst in the methanol steam reforming process. To study the connection between the catalytic properties of the surface and the structural and electronic properties of the bulk, we have grown single crystals of the InPd phase by the Czochralski method and determined their electronic, thermal, magnetic and hydrogen-absorption properties. By growing crystals from a high-temperature solution, we could crystallize a slightly off-stoichiometric In-rich composition In1.04Pd0.96, which contained a significant amount of constitutional defects in the lattice (Pd vacancies on the Pd sublattice) to retain the CsCl-type structure. The strongly inhomogeneously broadened In-115 NMR spectrum and the high residual (T -> 0) electrical resistivity confirmed the presence of constitutional defects. Single crystals of InPd do not absorb hydrogen, as requested for a good hydrogenation catalyst material. Calculated electronic density of states (DOS) shows large contribution of Pd(d) states at the Fermi level. Application of the electron localizability indicator reveals ionic and multi-centre In Pd interactions stabilizing the crystal structure. The electrical and thermal conductivities of InPd show metallic character, whereas the thermoelectric power and the Hall coefficient both show positive sign, revealing that InPd is a predominant hole-type conductor. The calculated electronic DOS at the Fermi energy is in a good agreement with the experimental value determined from the low-temperature specific heat. Magnetic measurements have shown that InPd is a diamagnet. All results are compared to the chemically related intermetallic compound GaPd. The active site-isolation concept for increased catalytic selectivity is discussed in relation to the InPd and GaPd structures.
(C) 2014 Elsevier Ltd. All rights reserved.

Intermetallics, 55, 56-65 (2014)

DOI: 10.1016/j.intermet.2014.07.007


151.

Pawlak M.A., Jodlowska E., Gierczyk B., Popenda Ł., Jurga S., Kaźmierski R.

Identification of multiple sclerosis cerebrospinal fluid biomarkers using nuclear magnetic resonance spectroscopy Nuclear Magnetic Resonance (NMR) spectroscopy identifies metabolites of small molecular weight present in cerebrospinal fluid (CSF). Diagnosis of multiple sclerosis (MS) and clinically isolated syndrome (CIS) is based on a combination of symptoms, laboratory tests and MRI results, and sometimes is not conclusive especially early in the disease process. Previous studies that employed NMR to examine the CSF of patients with CIS and MS focused mainly on differences and did not use receiver operator characteristics (ROC) curves statistics to assess the peaks. Additionaly they usually involved sample pH adjustment that could influence the metabolites and their stability.

Multiple Sclerosis Journal, 20(1), P265-186 (2014)

DOI: 10.1177/1352458514546077   (Pobrane:  2018-04-04)


150.

Kaźmierczak M., Pogorzelec-Glaser K., Hilczer A., Jurga S., Majchrzycki Ł., Nowicki M., Czajka R., Matelski F., Pankiewicz R., Łęska B., Kępiński L., Andrzejewski B.

Morphology and magnetic properties of Fe3O4 - alginic acid nanocomposites The morphology, structure and magnetic properties of the nanocomposites of magnetite (Fe3O4) nanoparticles and alginic acid (AA) are studied. Magnetite Fe3O4 nanoparticles and the nanoparticles capped with alginic acid exhibit very distinct properties. The chemical bonding between alginic acid and the surface of magnetite nanoparticles results in the recovery of surface magnetization. On the other hand, it also leads to the enhanced surface spin disorder and unconventional behavior of the magnetization observed in Fe3O4-AA nanocomposites at low temperatures.

Materiali in Technologije, 48(5), 675-678 (2014)

DOI: UDK: 620.3:66.017:621.318   (Pobrane:  2018-03-23)


149.

Zhukov I., Choudhury A.R., Sikorska E., Zuperl S., Popenda Ł., Szutkowski K., Novic M., Jurga S.

The FEBS Journal, 281, 647 (2014)


ISSN: 1742-464X   (Pobrane:  2018-03-23)


148.

Adrjanowicz K., Kamiński K., Dulski M., Jasiurkowska-Delaporte M., Kołodziejczyk K., Jarek M., Bartkowiak G., Hawelek L., Jurga S., Paluch M.

Dynamic glass transition and electrical conductivity behavior dominated by proton hopping mechanism studied in the family of hyperbranched bis-MPA polyesters Dielectric and infrared spectroscopies were employed to study inter- and intramolecular glass-transition dynamics in the series of hyperbranched polyesters of the second, third, and fourth generations. Our study shows that conductivity relaxation becomes increasingly faster than structural relaxation as the glass transition temperature Tg is approached, signifying decoupling between translational motions of charges and reorientation of molecules. Depending on the polymer's generation conductivity relaxation times can be up to few orders of magnitude faster than structural dynamics. Because of extensive hydrogen bonding network, the most significant contribution to the total ionic conductivity comes from proton transfer along hydrogen bonds. Decoupling phenomenon was accompanied by narrowing the dispersion of the conductivity relaxation with decreasing temperature that reaches almost exponential decay in the glassy state. Finally, by analyzing the absorption spectra in terms of integral intensity, we have demonstrated significant role of H-bonded moieties in the course of vitrification of investigated materials.

Macromolecules, 47(16), 5798-5807 (2014)

DOI: 10.1021/ma5006155   (Pobrane:  2018-03-23)


147.

Andrzejewski B., Bednarski W., Kaźmierczak M., Łapiński A., Pogorzelec-Glaser K., Hilczer B., Jurga S., Nowaczyk G., Załęski K., Matczak M., Łęska B., Pankiewicz R., Kępiński L.

Magnetization enhancement in magnetite nanoparticles capped with alginic acid We report on the effect of alginic acid capping on the behavior of magnetite nanoparticles. The capped nanoparticles exhibit improved crystalline structure of the surface which leads to an enhanced magnetization. The improved structure facilitates quantization of spin-wave spectrum in the finite size nanopartides and this in turn is responsible for unconventional behavior at low temperatures. In electron magnetic resonance these anomalies are manifested as an unusual increase in the resonant field H-r(T) and as a maximum of the spectroscopic splitting g(eff) parameter at low temperatures. This unconventional behavior leads also to pronounced upturn of magnetization at low temperatures and a deviation from the Bloch law M(T) similar to T-3/2.
© 2014 Elsevier Ltd. All rights reserved.

Composites Part B: Engineering, 64, 147-154 (2014)

DOI: 10.1016/j.compositesb.2014.04.022   (Pobrane:  2018-04-04)


146.

Gierczyk B., Kaźmierczak, M., Popenda Ł., Sporzyński A., Schroeder G., Jurga S.

Influence of fluorine substituents on the NMR properties of phenylboronic acids The paper presents results of a systematic NMR studies on fluorinated phenylboronic acids. All possible derivatives were studied. The experimental H-1, C-13, F-19, B-11, and O-17 spectral data were compared with the results of theoretical calculations. The relation between the calculated natural bond orbital parameters and spectral data (chemical shifts and coupling constants) is discussed. The first examples of B-10/B-11 isotopic effect on the F-19 spectra and (4)J(FO) scalar coupling in organic compounds are reported.
Copyright (C) 2014 John Wiley & Sons, Ltd.

Magnetic Resonance in Chemistry, 52(5), 202-213 (2014)

DOI: 10.1002/mrc.4051   (Pobrane:  2018-04-04)


145.

Iatsunskyi I., Jurga S., Smyntyna V., Pavlenko M., Myndrul V., Zaleska A.

Raman spectroscopy of nanostructured silicon fabricated by metal-assisted chemical etching In this work, we present a detailed experimental Raman investigation of nanostructured silicon films prepared by metal-assisted chemical etching with different nanocrystal sizes and structures. Interpretation of observed one and two-phonon Raman peaks are presented. First-order Raman peak has a small redshift and broadening. This phenomenon is analyzed in the framework of the phonon confinement model. Second-order Raman peaks were found to be shifted and broadened in comparison to those in the bulk silicon. The peak shift and broadening of two-phonon Raman scattering relates to phonon confinement and disorder. A broad Raman peak between 900-1100 cm(-1) corresponds to superposition of three transverse optical phonons similar to 2TO (X), 2TO (W) and 2TO (L). Influence of excitation wavelength on intensity redistribution of two-phonon Raman scattering components (2TO) is demonstrated and preliminary theoretical explanation of this observation is presented.

Proceedings of SPIE - Optical Micro- and Nanometrology V, 9132, 913217 (2014)

DOI: 10.1117/12.2051489
ISBN: 9781628410808   (Pobrane:  2021-01-11)


144.

Maciejewska B.M., Jasiurkowska-Delaporte M., Vasylenko A.I., Kozioł K.K., Jurga S.

Experimental and theoretical studies on the mechanism for chemical oxidation of multiwalled carbon nanotubes In this study, the oxidation of multiwalled carbon nanotubes (MWCNTs) sonicated and/or refluxed in acids (H2SO4/HNO3) was investigated using a combination of high-resolution transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and ab initio computational methods. Sonication of the sample has the strongest effect, leading to the highest concentration of defects and carboxyl groups on the walls. Substantial correlations between treatment protocols, CNT size, and the types of chemical moieties are observed. Finally, based on experimental and computational results, we suggest the mechanism of the oxidation process for attaching the functional groups on the sidewalls.

RSC Advances, 4(55), 28826-28831 (2014)

DOI: 10.1039/c4ra03881a


143.

Siuzdak K., Sawczak M., Klein M., Nowaczyk G., Jurga S., Cenian A.

Preparation of platinum modified titanium dioxide nanoparticles with the use of laser ablation in water We report on the preparation method of nanocrystalline titanium dioxide modified with platinum by using nanosecond laser ablation in liquid (LAL). Titania in the form of anatase crystals has been prepared in a two-stage process. Initially, irradiation by laser beam of a titanium metal plate fixed in a glass container filled with deionized water was conducted. After that, the ablation process was continued, with the use of a platinum target placed in a freshly obtained titania colloid. In this work, characterization of the obtained nanoparticles, based on spectroscopic techniques - Raman, X-ray photoelectron and UV-vis reflectance spectroscopy - is given. High resolution transmission electron microscopy was used to describe particle morphology. On the basis of photocatalytic studies we observed the rate of degradation process of methylene blue (MB) (a model organic pollution) in the presence of Pt modified titania in comparison to pure TiO2 - as a reference case. Physical and chemical mechanisms of the formation of platinum modified titania are also discussed here. Stable colloidal suspensions containing Pt modified titanium dioxide crystalline anatase particles show an almost perfect spherical shape with diameters ranging from 5 to 30 nm. The TiO2 nanoparticles decorated with platinum exhibit much higher (up to 30%) photocatalytic activity towards the degradation of MB under UV illumination than pure titania.

Physical Chemistry Chemical Physics, 30(9), 2505-2512 (2014)

DOI: 10.1039/c4cp01923g   (Pobrane:  2018-03-23)


142.

Jenczyk J., Dobies M., Makrocka-Rydzyk M., Wypych A., Jurga S.

The segmental and global dynamics in lamellar microphase-separated poly(styrene-b-isoprene) diblock copolymer studied by 1H NMR and dielectric spectroscopy The nuclear magnetic resonance (NMR) and dielectric spectroscopy (DS) methods were used to investigate the segmental and global dynamics in lamellar microphase separated poly(styrene-b-isoprene) (SI) diblock copolymer. For the first time, the susceptibility representation of the NMR relaxation data is applied to the analysis of the molecular dynamics in complex polymer systems like the diblock copolymer. This approach in combination with the frequency-temperature superposition (FTS) allows one to compare directly the NMR and DS data in an extended frequency range providing a unique comprehensive picture of various relaxation processes present in the system studied. The findings of these investigations include structural relaxations of the polyisoprene (PI) and the polystyrene (PS) blocks, a normal mode relaxation of the PI block, and an extra low frequency interfacial relaxation. Special attention has been devoted to influence of the copolymer morphology on the segmental and global dynamics in PI.
(C) 2013 Published by Elsevier Ltd.

European Polymer Journal, 49(12), 3986-3997 (2013)

DOI: 10.1016/j.eurpolymj.2013.09.003   (Pobrane:  2020-10-23)


141.

Choudhury A.R., Perdih A., Župerl Š., Sikorska E. Solmajer T., Jurga S., Zhukov I., Novič M.

Structural elucidation of transmembrane transporter protein bilitranslocase: Conformational analysis of the second transmembrane region TM2 by molecular dynamics and NMR spectroscopy Membrane proteins represent about a third of the gene products in most organisms, as revealed by the genome sequencing projects. They account for up to two thirds of known drugable targets, which emphasizes their critical pharmaceutical importance. Here we present a study on bilitranslocase (BTL) (TCDB 2.A.65), a membrane protein primarily involved in the transport of bilirubin from blood to liver cells. Bilitranslocase has also been identified as a potential membrane transporter for cellular uptake of several drugs and due to its implication in drug uptake, it is extremely important to advance the knowledge about its 3D structure. However, at present, only a limited knowledge is available beyond the primary structure of BTL It has been recently confirmed experimentally that one of the four computationally predicted transmembrane segments of bilitranslocase, TM3, has a helical structure with hydrophilic amino acid residues oriented towards one side, which is typical for transmembrane domains of membrane proteins. In this study we confirmed by the use of multidimensional NMR spectroscopy that the second transmembrane segment, TM2, also appears in a form of alpha-helix. The stability of this polypeptide chain was verified by molecular dynamics (MD) simulation in dipalmitoyl phosphatidyl choline (DPPC) and in sodium dodecyl sulfate (SDS) micelles. The two alpha-helices, TM2 corroborated in this study, and TM3 confirmed in our previous investigation, provide reasonable building blocks of a potential transmembrane channel for transport of bilirubin and small hydrophilic molecules, including pharmaceutically active compounds.
(C) 2013 Elsevier B.V. All rights reserved.

Biochimica et Biophysica Acta, 1828(11), 2609-2619 (2013)

DOI: 10.1016/j.bbamem.2013.06.006


140.

Adrjanowicz K., Kaminski K., Wlodarczyk P., Grzybowska K., Tarnacka M., Zakowiecki D., Garbacz G., Paluch M., Jurga S.

Molecular dynamics of the supercooled pharmaceutical agent posaconazole studied via differential scanning calorimetry and dielectric and mechanical spectroscopies This paper presents comprehensive studies on the molecular dynamics of a pharmaceutically important substance, posaconazole. In order to characterize relaxation dynamics in the supercooled liquid and glassy states, dielectric and mechanical spectroscopies were applied. Dielectric data have indicated multiple relaxation processes that appear above and below the glass transition temperature Tg (tau(alpha) = 100 s) of posaconazole. From the curvature of the dielectric log(10)(tau(alpha)) versus inverse of temperature dependence, we determine so-called "fragility", being a very popular parameter for classifying the structural dynamics of supercooled liquids and polymers. From the calculations, we get m = 150, which means that is one of the most fragile glass-forming liquids. In this paper, the relaxation dynamics of supercooled posaconazole extracted from the dielectric response function was also confronted with shear-mechanical relaxation. Finally, we have also presented a direct comparison of the fragility and the number of dynamically correlated molecules N-c determined from dynamic calorimetry curves and dielectric and mechanical spectroscopies, showing a clear deviation in the picture of glass-transition dynamics generated by calorimetric and spectroscopic techniques.

Molecular Pharmaceutics, 10(10), 3934-3945 (2013)

DOI: 10.1021/mp4003915


139.

Strankowska J., Piszczyk L., Strankowski M., Danowska M., Szutkowski K., Jurga S., Kwela J.

Molecular dynamics studies of polyurethane nanocomposite hydrogels Polyurethane PEO-based hydrogels have a broad range of biomedical applicability. They are attractive for drug-controlled delivery systems, surgical implants and wound healing dressings. In this study, a PEO based polyurethane hydrogels containing CloisiteA (R) 30B, an organically modified clay mineral, was synthesized. Structure of nanocomposite hydrogels was determined using XRD technique. Its molecular dynamics was studied by means of NMR spectroscopy, DMA and DSC analysis. The mechanical properties and thermal stability of the systems were improved by incorporation of clay and controlled by varying the clay content in polymeric matrix. Molecular dynamics of polymer chains depends on interaction of CloisiteA (R) 30B nanoparticles with soft segments of polyurethanes. The characteristic nanosize effect is observed.

European Physical Journal - Special Topics, 222(9), 2179-2186 (2013)

DOI: 10.1140/epjst/e2013-01994-8


138.

Adrjanowicz K., Kamiński K., Dulski M., Włodarczyk P., Bartkowiak G., Popenda Ł., Jurga S., Kujawski J. Kruk J., K. Bernard M., Paluch M.

Synperiplanar to antiperiplanar conformation changes as underlying the mechanism of Debye process in supercooled ibuprofen In this Communication, we present experimental studies that put new insight into the puzzling nature of the Debye relaxation found in the supercooled liquid state of racemic ibuprofen. The appearance of D-relaxation in the loss spectra of non-hydrogen bonding methylated derivate of ibuprofen has proven that Debye relaxation is related solely with conformational changes of the carboxyl group, termed in this paper as synperiplanar-antiperiplanar. Our studies indicate that the presence of hydrogen bonding capabilities is not here the necessary condition to observe Debye process, however, their occurrence might strongly influence α- and D-relaxations dynamics. Interestingly, the activation energy of the D-process in ibuprofen methyl ester on approaching Tg was found to be perfectly consistent with that reported for ibuprofen by Affouard and Correia [J. Phys. Chem. B 114, 11397–11402 (2010)] (∼39 kJ/mol). Finally, IR measurements suggest that the equilibrium between conformers concentration depends on time and temperature, which might explain why the appearance of D-relaxation in supercooled ibuprofen depends on thermal history of the sample.
(C) 2013 AIP Publishing LLC.

Journal of Chemical Physics, 139(11), 111103-4 (2013)

DOI: 10.1063/1.4820492   (Pobrane:  2020-10-25)


137.

Park S., Cho H.Y., Wegner K.B., Burdynska J., Magenau A.J.D., Paik H.J., Jurga S., Matyjaszewski K.

Star synthesis using macroinitiators via electrochemically mediated atom transfer radical polymerization Electrochemically mediated atom transfer radical polymerization (eATRP) was investigated for synthesis of star polymers using macroinitiators (MIs), achieving high star yield with low Cu catalyst loading (similar to 100 ppm, w/w). The arm first method, using MIs, is one of the most robust procedures for star polymer synthesis. During the polymerization, MIs can react with cross-linkers (divinyl or multivinyl compounds) for initial chain extension followed by the cross-linking reaction. The MIs can be transformed to arms of the star, and the cross-linker can form the star core. In this study, poly(ethylene oxide) (PEO, M-n = 2000) based MIs (PEO MIs) were prepared, and the chain-end functionalities were confirmed by H-1 NMR analysis. The ATRP functionalized PEO MIs were then used for the star synthesis by reacting with ethylene glycol diacrylate cross-linkers. Various experimental conditions were conducted for optimizing star formation, including MI concentration, MI to cross-linker molar ratio, and applied potential (E-app).

Macromolecules, 46(15), 5856-5860 (2013)

DOI: 10.1021/ma401308e


136.

Wypych A., Szpotkowski K., Jurga S., Domka L., Kozak M.

Interactions of a cationic surfactant - (benzyloxymethyl) dodecyldimethylammonium chloride with model biomembrane systems Phospholipids are the main components of biological membranes. The aim of the present study was to determine the influence of a cationic surfactant on phospholipid structure and dynamics. Fourier transform infrared (FTIR) and dielectric relaxation (DRS) spectroscopies as well as small-angle Xray scattering (SAXS) with synchrotron radiation have been used to analyse the structure of fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) in the presence of a quaternary ammonium surfactant: (benzyloxymethyl) dodecyldimethylammoniumchloride (BzMDDAC). The presence of the surfactant caused changes in the temperature of the DMPC phase transition, as revealed using FTIR and DRS measurements. This change results from the disappearance of the multilamellar phase of DMPC and the formation of the unilamellar (most likely bicellar) phase, as indicated by the SAXS results.
(C) 2013 Elsevier B.V. All rights reserved.

Colloids and Surfaces B: Biointerfaces, 108, 212-218 (2013)

DOI: 10.1016/j.colsurfb.2013.03.010   (Pobrane:  2021-01-20)


135.

Zhukov I., Lubecka E.A., Popenda Ł., Stodus K., Jurga S.

The FEBS Journal, 280 S1 SI, 161 (2013)


ISSN: 1742-464X   (Pobrane:  2018-03-22)


134.

Makrocka-Rydzyk M., Wypych A., Dobies M., Jancelewicz M., Jurga S., Cho HY., Gao HF., Matyjaszewski K.

Molecular dynamics in PBA/PEO miktoarm star copolymers Molecular dynamics of miktoarm star copolymers consisting of poly(n-butyl acrylate) PBA and polyethylene oxide (PEO) arms was studied by means of Broadband Dielectric Spectroscopy (BDS) and Nuclear Magnetic Resonance (NMR) methods. The spectroscopic studies were performed for three types of copolymers differing in the composition, namely materials containing 76%, 46% and 16% molar fraction of PBA arms. The local processes, described by the Arrhenius law (e.g. the anisotropic rotation of methyl groups and the anisotropic local motions in the PEO chain), were observed for the studied systems below the glass transition temperature. It was found that the investigated PBA/PEO miktoarm star copolymers are characterized by single glass transition, which may result from similar values of glass transition temperatures of the PBA and PEO polymers. The segmental dynamics in the studied systems was quantitatively described by using the Vogel-Fulcher-Tammann (VFT) relation applied to combined NMR and BDS data. Moreover, above the glass transition temperature the interfacial polarization and conductivity phenomena were detected with the BDS method for all systems under study.
(C) 2013 Elsevier Ltd. All rights reserved.

Polymer, 54(13), 3341-3349 (2013)

DOI: 10.1016/j.polymer.2013.04.004


133.

Cho H.Y., Averick S.E., Paredes E., Wegner K., Averick A., Jurga S., Das S.R., Matyjaszewski K.

Star polymers with a cationic core prepared by ATRP for cellular nucleic acids delivery Poly(ethylene glycol) (PEG)-based star polymers with a cationic core were prepared by atom transfer radical polymerization (ATRP) for in vitro nucleic acid (NA) delivery. The star polymers were synthesized by ATRP of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and ethylene glycol dimethacrylate (EGDMA). Star polymers were characterized by gel permeation chromatography, zeta potential, and dynamic light scattering. These star polymers were combined with either plasmid DNA (pDNA) or short interfering RNA (siRNA) duplexes to form polyplexes for intracellular delivery. These polyplexes with either siRNA or pDNA were highly effective in NA delivery, particularly at relatively low star polymer weight or molar ratios, highlighting the importance of NA release in efficient delivery systems.

Biomacromolecules, 14(5), 1262-1267 (2013)

DOI: 10.1021/bm4003199   (Pobrane:  2018-03-22)


132.

Rucińska-Sobkowiak R., Nowaczyk G., Krzeszowska M., Ramęda I., Jurga S.

Water status and water diffusion transport in lupine roots exposed to lead Water status and diffusion transport were studied in the roots of yellow lupine (Lupinus Luteus L, cv. Juno) treated for 48h with two selected concentrations of Pb(NO3)(2): 150 mg l(-1), which inhibited root growth by about 50% (medium stress intensity), as well as 350 mg l(-1), which almost entirely suppressed root elongation (severe stress intensity). Relative water content (RWC), which characterizes the degree of root water saturation, slightly increased at the lower lead concentration and remained unchanged at the higher lead dose. Ultrastructure analyses under a transmission electron microscope revealed that plasmolysis was not evoked by lead in the apical part of the meristem. Moreover, direct observation of meristem cells using Nomarsky optics indicated enhanced vacuolization in the presence of both lead concentrations. These data suggest that the water status of the roots was not affected by the metal. Due to the fact that proline is involved in the maintenance of turgor in the cells, the metabolism of this amino acid was investigated. In the roots, the activity of enzymes involved in proline synthesis, such as pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT), increased at 150 mg l(-1) Pb2+; nevertheless, proline content was diminished at the lower lead concentration. This effect is likely the result of proline degradation by proline dehydrogenase (PDH), since the activity of this enzyme increased at the lower lead dose. On the other hand, in the presence of 350 mg l(-1) Pb2+, a low level of proline was correlated with a decrease in the activity of P5CS and OAT, as well as unchanged PDH activity in lupine roots. These data may imply that enzymatic synthesis of proline was strongly damaged by the metal ions. The low level of proline in both experimental variants suggests that proline accumulation is inessential to maintaining the osmotic uptake of water into root cells. NMR spectroscopy showed that exposition of lupine seedlings to lead caused a deceleration in water transport in the roots due to a reduction in the water transfer rate across the membranes (transmembrane transfer) and vacuoles continuum, as well as water diffusion along the root apoplast. Fluorescence staining and immunogold labeling showed the presence of callose strands in cell walls and/or in the vicinity of them. In lead-treated lupine roots, callose was mainly localized in the parenchyma cortex placed lengthwise to the vascular cylinder. Callose deposits in the cell walls may reduce vacuolar transport, as well as increase cell wall resistance to water flow. Deceleration of diffusional water movement to the vascular system, may in turn, influence the rate of long-distance water transport to aerial parts of the plant.
(C) 2012 Elsevier B.V. All rights reserved.

Environmental and Experimental Botany, 87, 100-109 (2013)

DOI: 10.1016/j.envexpbot.2012.09.012


131.

Makrocka-Rydzyk M., Wegner K., Szutkowski K., Kozak M., Jurga S., Gao H.

Morphology and NMR self-diffusion in PBA/PEO miktoarm star copolymers Morphology and NMR self-diffusion of two miktoarm star copolymers differing in fraction of poly(n-butyl acrylate) and poly(ethylene oxide) (PBA and PEO) arms were under investigation. Structural characteristics of copolymers was obtained on the basis of Small Angle X-Ray Scattering (SAXS) investigations. The phase separated nanoscale morphology of the miktoarm star copolymer with a high fraction of PEO arms was confirmed by Scanning Probe Microscopy (SPM) studies. The modified Avrami approach was used to obtain the information on the non-isothermal crystallization kinetics of the studied systems. It was observed that the crystallization in the system with a higher content of PBA, occurring at higher undercooling, was characterized by a higher crystallization rate. It was also found that increase in PBA arms fraction leads to the reduction in the size of PEO domains. The activation energy of the crystallization process, estimated with Kissinger's method, is lower for miktoarm star copolymer with higher PBA content, which results from facilitation of the transport of PEO chains in the direction of the growing crystal due to the presence of mobile PBA arms. The self-diffusion studies of miktoarm star copolymers melts, carried out with the Pulsed-Gradient STimulated-Echo (PGSTE) Nuclear Magnetic Resonance (NMR) technique, reveals the existence of at least two types of diffusion mechanisms in these systems.

Zeitschrift für Physikalische Chemie, 226, 1271-1292 (2012)

DOI: 10.1524/zpch.2012.0300   (Pobrane:  2020-10-23)


130.

Strankowski M., Strankowska J., Gazda M., Piszczyk L., Nowaczyk G., Jurga S.

Thermoplastic polyurethane/(organically modified montmorillonite) nanocomposites produced by in situ polymerization A series of polyurethane nanocomposites were synthesized from thermoplastic polyurethanes (with different hard segment ratios) and two types of organically modified montmorillonites (OMMT) - Cloisite (R) 10A and Cloisite (R) 20A. The thermal behavior was examined by non-isothermal thermogravimetry (TG, DTG), Differential Scanning Calorimetry (DSC) and Dynamic-Mechanical Thermal Analysis (DMTA). The results of X-ray analyses showed that the OMMT produced the intercalated polyurethane nanocomposites. It has been proven that the thermal stability and tensile properties of these new systems were higher when the organoclay was present within the polymer matrix. Moreover, these properties depend on both the OMMT loading and the type of gallery cations of the organically modified montmorillonites.

Express Polymer Letters, 6(8), 610-619 (2012)

DOI: 10.3144/expresspolymlett.2012.65


129.

Strankowska J., Fojud Z., Jurga S., Strankowski M., White J.L.

Polymer-dependent layer structures in montmorillonite nanocomposites We have studied structural differences among tetrahedral and octahedral sodium Montmorillonite layer arrangements in naturally occurring and synthetic montmorillonite clay minerals, as well as their poly(ethylene oxide) and poly(epsilon-coprolatone) polymer nanocomposites.

Journal of Analytical Science & Technology, 2(A), A22-A30 (2011)

DOI: 10.5355/JAST.2011.A22
WWW: http://www.jastmag.org/journal/view.php?number=52


128.

Makrocka-Rydzyk M., Wypych A., Szpotkowski K., Kozak M., Jurga S., Gao H.F., Cho H.Y., Matyjaszewski K.

Structural studies of poly(butyl acrylate) - poly(ethylene oxide) miktoarm star polymers Structural behavior of miktoarm star polymers comprising poly(butyl acrylate) (PBA) and poly(ethylene oxide) (PEO) arms was studied by means of Differential Scanning Calorimetry (DSC), Wide Angle X-Ray Scattering (WAXS), Polarized Optical Microscopy (POM) and Fourier Transform Infrared Spectroscopy (FTIR) methods. The aim of this study was to correlate changes in the composition of the arms of the PBA/PEO miktoarm star polymers with their structures. As a consequence of increasing PBA content, the decrease in crystallinity of the studied PBA/PEO heteroarm star copolymers was observed. Regardless of the copolymer composition, fraction of oxyethylene units in the crystalline PEO phase was similar in all investigated systems. The POM images showed spherulitic morphology of the materials having low PBA content, while an increase in PBA arms fraction leads to the formation of less ordered structures. The analysis of FTIR vibrational spectrum indicates helical conformation of PEO chains in the crystalline phase. Isothermal crystallization studies carried out using the FTIR technique suggest the existence of isolated domains in the nanoscopic scale of investigated materials.

Polymer, 52(24), 5513-5520 (2011)

DOI: 10.1016/j.polymer.2011.09.020   (Pobrane:  2020-10-23)


127.

Jancelewicz M., Fojud Z., Waszkowiak W., Jurga S.

Local mobility in grafted polydimethylsiloxane melts Spin-lattice relaxation time constants T(1) were studied for low-molecular-weight linear and grafted polydimethylsiloxane over a wide temperature and frequency range Quantitative evaluations of proton T(1) measurements indicated two relaxation processes anisotropic rotation of methyl groups around the Si-C bond (low temperature process) and motions of the PDMS side-chains connected with the glass transition (high temperature process) Additional analyses of the T(1) relaxation dispersion profiles revealed specific local segment fluctuation times which are characteristic of the coherent motions in the grafted polymer chains.
(C) 2010 Elsevier Ltd All rights reserved

European Polymer Journal, 47(1), 48-51 (2011)

DOI: 10.1016/j.eurpolymj.2010.10.032


126.

Krzaczkowska J., Strankowski M., Jurga S., Jurga K., Pietraszko A.

NMR dispersion studies of poly(ethylene oxide)/sodium montmorillonite nanocomposites The frequency dependence of spin lattice relaxation times measured by means of Fast Field Cycling (FFC) Relaxometry and spin locking on and off-resonance NMR techniques were used to study the molecular dynamics of poly(ethylene oxide) polymer in the confined and bulk phases of PEO/MMT nanocomposite systems. The Rouse model, the renormalized Rouse formalism and the concept of reptation were applied to describe the polymer behavior in the samples studied. The polymer dynamics was found to depend on the molecular weight of the polymer intercalated in the clay structure. Analysis of the NMR T(1)(nu) profiles allowed discrimination of the molecular dynamics of polymer chains at different locations in the nanocomposite structure. Two components of the T(1) spin-lattice relaxation times were indicated for low molecular weight PEO polymers using the FFC method. The longer one was connected with the bulk polymer, whereas the shorter one was attributed to the intercalated polymer fraction. Analysis of the correlation times indicated that polymer confined in montmorillonite galleries is more rigid than that in the bulk phase. To determine the two phases of the polymer for the high molecular weights polymers, additional methods were applied: spin locking, off-resonance NMR techniques and inversion-recovery experiment at a static magnetic field.
(C) 2010 Elsevier B.V. All rights reserved.

Journal of Non-Crystalline Solids, 356(20-22), 945-951 (2010)

DOI: 10.1016/j.jnoncrysol.2010.02.005


125.

Jenczyk J., Makrocka-Rydzyk M., Wypych A., Głowinkowski S., Jurga S., Radosz M.

The phase structure and molecular dynamics in poly(styrene-b-isoprene) diblock copolymer Molecular dynamics of polyisoprene, polystyrene and poly(styrene-b-isoprene) diblock copolymer has been studied by means of broadband dielectric and magnetic resonance spectroscopies. The measurements of dielectric permittivity as well as NMR second moment, spin-lattice relaxation times T(1) and T(1ρ), in wide range of temperature were performed. It was found that the copolymer exhibits all motions observed in the neat components i.e., three motions connected with polyisoprene blocks (segmental, normal-mode and methyl group rotation) and one (segmental) related to polystyrene blocks. The mutual interaction between polystyrene and polyisoprene chains leads to stiffening of polyisoprene blocks and loosening of polystyrene structure. The polyisoprene segmental and normal-mode motions were analyzed in terms of the Havriliak-Negami model and Vogel-Fulcher-Tamman (VFT) relation. Based on NMR spin-diffusion experiment the size of polystyrene domains in copolymer was evaluated and accounts to 9 nm.
(C) 2010 Elsevier B.V. All rights reserved.

Journal od Non-Crystalline Solids, 356(11-17), 582-588 (2010)

DOI: 10.1016/j.jnoncrysol.2009.06.046   (Pobrane:  2020-10-23)


124.

Jancelewicz M., Nowaczyk G., Makrocka-Rydzyk M., Wypych A., Fojud Z., Jurga S., Maciejewski H.

Molecular dynamics in grafted polydimethylsiloxanes Rheological and dielectric behavior of linear PDMS and alkyl-modified PDMS melts has been studied. Molecular dynamics of linear PDMS, being a model of grafted polydimethylsiloxanes studied, has been examined carefully with particular attention paid to its ability to form the semicrystalline phase. Random incorporation of alkyl groups into PDMS chain has been shown to prevent the polymer crystallization. The glass transition temperature of the grafted PDMS changes proportionally to the modifier content. Both techniques allow characterization of the main alpha-relaxation, which is related to the glass transition and exhibits similar behavior in all systems. This relaxation is discussed in terms of the Vogel-Fulcher-Tammann-Hesse (VFTH) approach. The fragility of grafted PDMS materials was found to be higher as compared to the linear polymer. The analysis of the rheological data shows the existence of additional slow relaxation, which has been interpreted as the polymer chain motion.
(C) 2010 Elsevier B.V. All rights reserved.

Journal of Non-Crystalline Solids, 356(11-17), 669-675 (2010)

DOI: 10.1016/j.jnoncrysol.2009.07.036   (Pobrane:  2020-10-21)


123.

Kozak M., Wypych A., Szpotkowski K., Jurga S., Skrzypczak A.

Structural and spectroscopic studies of DMPC/cationic surfactant system Aqueous suspension of a mixture of 1,2-dimyrilstoyl-sn-glycero-3-phosphocholine (DMPC) and (dodecyloxymethyl)dodecydimethylammonium (DDMDDAC) has been investigated by Fourier transform infrared spectroscopy (FTIR), small angle scattering of synchrotron radiation (SAXS) and dielectric spectroscopy (DS). The introduction of surfactant to DMPC water solution probably induces formation of discoidal (bicellar) phase, as revealed by SAXS studies. The presence of the surfactant has been found to decrease the main phase transition temperature, i.e., from rippled gel to liquid crystalline phase, as indicated by the DS and FTIR results. The small steps in the real part of dielectric permittivity plot vs. temperature can be related to the: planar gel to rippled gel (L(beta') -> P(beta')) and rippled gel-liquid crystal (P(beta') -> L(alpha)) phase transitions, which is supported by the temperature dependencies of the symmetric and anti-symmetric CH(2) band frequencies from FTIR measurements.
(C) 2010 Elsevier B.V. All rights reserved.

Journal of Non-Crystalline Solids, 356(11-17), 747-753 (2010)

DOI: 10.1016/j.jnoncrysol.2009.07.043


122.

Makrocka-Rydzyk M., Nowaczyk G. , Głowinkowski S., Jurga S.

Dynamic mechanical study of molecular dynamics in ethylene-norbornene copolymers Dynamic mechanical studies of Molecular dynamics have been performed for two ethylene-norbornene copolymers. The analysis of data indicates the existence of three relaxation processes: a primary (alpha) and two secondary (beta and gamma) ones. It was found that the secondary processes beta and gamma are connected with the local motions of ethylene and norbornene groups, respectively and that their rates follow the Arrhenius relation. Moreover, the beta process was recognized as the Johari-Goldstein process acting as the precursor of the cooperative structural alpha-relaxation. Contrary to gamma and beta processes, the motional rate of alpha-one follows the Vogel-Fulcher-Tammann equation indicating the cooperative nature of motions involved in this process. An increase in norbornene content in copolymer slows down the molecular dynamics of both norbornene fragments and whole chains, and in consequence shifts these relaxation Processes into higher temperatures. Using the Havriliak-Negami formalism the motional parameters for the processes mentioned above were estimated.
(C) 2009 Elsevier Ltd. All rights reserved.

Polymer, 51(4), 908-912 (2010)

DOI: 10.1016/j.polymer.2009.12.027


121.

Szutkowski K., Jurga S.

Long-range ordering in lyotropic lamellar phase studied by high resolution MR diffusion-weighted imaging Diffusion-weighted magnetic resonance imaging (DW MRI) was applied to the lyotropic lamellar phase of the dodecylammonium chloride/water system (DDACl/H(2)O). In the course of employing a well-known medical imaging method, namely, diffusion tensor imaging (DTI), the system morphology was assessed accurately ill the most straightforward way by two-dimensional visualization of eigenvectors associated with planar distribution of effective diffusion tensors throughout the whole slice with 40 mu m in-plane resolution. Long-range order was observed in the Studied lamellar phase, and morphology was best described by a combination of three- and one-dimensional diffusion.

The Journal of Physical Chemistry B, 114(1), 165-173 (2010)

DOI: 10.1021/jp9072087


120.

Dobies M., Kozak M., Jurga S., Grubb A.

The dispersion of water proton spin-lattice relaxation rates in aqueous human protein HC (α1 - microglobulin) solutions The H-1 NMR Fast Field Cycling relaxometry was applied to study the molecular dynamics of the human protein HC (alpha(1)-microglobulin), its hydration and aggregation in solution state. The H-1 NMRD data have revealed the complex nature of the water/protein HC system resulting from the co-existence of monomer and dimer forms of the protein in solution as well as the presence of oligosaccharides linked to the polypeptide chain. A comparison of the average correlation time values obtained from the model-free fits with the values predicted on the basis of hydrodynamic tau(r) theory, suggests that the dynamics in solution state is governed mainly by the dimer form of the protein HC (the dominant contribution to the water proton-spin lattice relaxation comes from exchanging protons from the surface of the dimer). The existence of small number of oligomeric forms of the protein HC in solutions is postulated because of the two-step shape of water proton spin-lattice relaxation rate dispersion profiles.

Protein and Peptide Letters , 16(12), 1496-1503 (2009)

DOI: 10.2174/092986609789839241


119.

Żogał O.J., Fojud Z., Herzig P., Pietraszko A., Lyashchenko A.B., Jurga S., Paderno V.N.

Crystal structure, electric field gradient, and electronic charge densities in ReB2: A single crystal X-ray, 11B nuclear magnetic resonance (NMR) and first-principles study We have grown a single crystal of ReB2 and refined its crystal structure. Our structural studies confirmed the hexagonal structure (space group P6(3)/mmc) with lattice parameters a=2.8982(1) A degrees and c=7.4723(3) A degrees. We also report the observation of first order satellites in the B-11 nuclear magnetic resonance, which indicated the presence of a nonzero quadrupole coupling frequency, nu(Q)=276 ± 3 kHz, and an asymmetry parameter eta=0 at the boron atom sites. These values are in excellent agreement with electric-field-gradient (EFG) tensor calculations based on first principles. These calculations showed that the principal axis of the most negative EFG-tensor component, V-ZZ, is parallel to the c-axis of the crystal. This behavior is in agreement with the observed excess of B p(z) charge (c direction) over the p(x) and p(y) charges and is related to stronger metal-boron bonds compared to previously studied YB12 and LaB6, where the B-B bonds are stronger. Finally, the bonding properties of ReB2 are discussed in terms of densities of states, valence-electron densities, and partial charges.

Journal of Applied Physics, 106(3), 033514-5 (2009)

DOI: 10.1063/1.3190529


118.

Szpotkowski K., Kozak M., Kozak A., Zieliński R., Wieczorek D., Jurga S.

Structural studies of selected DSPC-surfactant model systems of biological membranes Fourier transform infrared spectroscopy was used to analyse the influence of a cationic surfactant from the group of morpholine derivatives on the conformational dynamics of CH2 group in acyl chain of DSPC. The presence of the surfactant causes a decrease in the DSPC phase transition temperature. This result suggests that the surfactant interactions with phospholipid molecules disturb the lipid layers. The Fourier transform infrared measurements were supplemented with tests of the environmental toxicity of the surfactant used.

Acta Physica Polonica A , 115(2), 561-564 (2009)

DOI: 10.12693/APhysPolA.115.561
WWW: http://przyrbwn.icm.edu.pl/APP/PDF/115/a115z225.pdf   (Pobrane:  2021-01-10)


117.

Dobies M., Kempka M., Kuśmia S., Jurga S.

Acid induced gelation of low methoxyl pectins studied by 1H NMR and rheological methods The various 1H NMR techniques (1H NMRD, water proton spin-spin relaxation time and diffusion measurements) in combination with rheological measurements were applied to the analysis of the acid induced gelation of 3% w/w aqueous LM pectin solutions at 279 K. A decrease of the pH value of solutions from 5 to 2.6 leads to a slowdown in the dynamics of the water molecules and to a substantial modification in the structure of the system studied. The most significant changes in the 1H NMRD and T2 measurements were observed when the pH was varied from 5 to 3, which reflected an increase in the stiffness of the pectin chains caused by non-ionic associations and by an increase of water molecules that were trapped between the pectin chains in the gelled ste. The results obtained by the rheological method are consistent with those of 1H NMR, indicating a solution-like mechanical response for the sample at pH 5 and a gel-like response at pH 3. Results of 1H NMR measurements have also shown an important role for aggregation processes of the LM pectin molecules in the acid-induced gel network formation.

Applied Magnetic Resonance, 34(1-2), 71-81 (2008)

DOI: 10.1007/s00723-008-0107-7   (Pobrane:  2020-10-21)


116.

Nozirov F., Fojud Z., Jancelewicz M., Nazirov A., Jurga S.

Molecular motion in the biocopolymer sequence of glycolide and lactide studied by solid state NMR This paper reports a nuclear magnetic resonance study of the molecular motion in copolymers derived from glycolide and L-lactide in the solid state. Variation of T-1 relaxation times with temperature reflects a local disorder and the fast segment conformational motions which can be quantified in terms of correlation times predicted by the Bloembergen-Purcell-Pound and Davidson-Cole models. At low temperatures, spin relaxation is dominated by the axial methyl rotation in lactide units described by an asymmetry parameter of the correlation time delta which takes a value of about 0.45 for all systems. Above the devitrification points the trans and gauche isomerization in glycolide segments occurs. In addition to the chemical structure characterization, solid-state magic-angle spinning spectroscopy gives an insight into the role of glycol segments in the chain mobility.

Applied Magnetic Resonance, 34(1-2), 193-203 (2008)

DOI: 10.1007/s00723-008-0102-z   (Pobrane:  2020-10-23)


115.

Zalewski T., Lubiatowski P., Jaroszewski J., Szcześniak E., Kuśmia S., Kruczyński J., Jurga S.

Scaffold-aided repair of articular cartilage studied by MRI Objective The objective of the study was to evaluate the ability of the noninvasive magnetic resonance techniques to monitor the scaffold-aided process of articular cartilage repair.
Materials and methods Defects of 4 mm in diameter and 3 mm in depth were created in right knees of 30 adolescent white New Zealand rabbits. Fourteen rabbits were implanted with poly(lactide-co-glycolic acid) (PLGA) scaffold trimmed to match the size and the shape of the defect (PLGA+ group). No procedure was applied to the remaining 16 animals (PLGA- group). Animals were sacrificed sequentially at 4, 12, and 24 weeks after the surgery and magnetic resonance T(2)-weighted images (400 MHz) of the dissected bone plugs at eight different echo times were taken to derive T(2) relaxation time. The images and the T(2) time dependencies versus the tissue depth were statistically analyzed. Histological results of bone plugs were evaluated using semiquantitative histological scales.
Results The results obtained for PLGA repair tissue were evaluated versus the PLGA- group and the healthy tissue harvested from the opposite knee (reference group), and compared with histological results (hematoxylin and eosin staining). The magnetic resonance images and T(2) relaxation time profiles taken 4 weeks after surgery for both the PLGA- and PLGA+ group did not reveal the tissue reconstruction. After 12 weeks of treatment T(2) time dependence indicates a slight reconstruction for PLGA+ group. The T(2) time dependence obtained for PLGA+ samples taken after 24 weeks of treatment resembled the one observed for the healthy cartilage, indicating tissue reconstruction in the form of fibrous cartilage. The tissue reconstruction was not observed for PLGA-samples.
Conclusion The study revealed correlation between magnetic resonance and histology data, indicating the potential value of using MRI and spatial variation of T (2) as the noninvasive tools to evaluate the process of articular cartilage repair. It also suggested, that the PLGA scaffold-aided treatment could help to restore the proper architecture of collagen fibrils.

Magnetic Resonance Materials in Physics, Biology and Medicine, 21(3), 177-185 (2008)

DOI: 10.1007/s10334-008-0108-4   (Pobrane:  2020-10-21)


114.

Herzig P., Fojud Z., Żogał O. J., Pietraszko A., Dukhnenko A., Jurga S., Shitsevalova N.

Electric-field gradient tensor and charge densities in LaB6: 11B NMR single-crystal investigations and first-principles calculations B-11 nuclear-magnetic-resonance measurements on a B-11 enriched single crystal of LaB6 have been performed at room temperature at a frequency of 128.4 MHz. The electric-field-gradient (EFG) tensor components have been determined from the angle dependence of the quadrupole splittings associated with (-3/2 <->-1/2) and (3/2 <-> 1/2) satellite transitions. These EFG components have been calculated using first-principles methods. Very satisfactory agreement with the experimental values has been obtained. The calculations show that the largest component of the EFG tensor mainly comes from the pp part of the so-called sphere component. The principal axis for the most negative EFG component is oriented in direction of the shortest and strongest bond between neighboring B atoms, which belong to two different B-6 units (interoctahedral B-B bonds). The fact that these interoctahedral B-B bonds are aligned in three different directions is responsible for the observation of up to three satellite pairs, although all boron atoms are crystallographically equivalent and there exists only one EFG tensor. Apart from the EFG investigations, chemical bonding in LaB6 is analyzed from densities of states and electron-density plots.
(C) 2008 American Institute of Physics.

Journal of Applied Physics, 103(8), 083534-7 (2008)

DOI: 10.1063/1.2903150   (Pobrane:  2020-10-21)


113.

Wąsicki J., Fojud Z., Czarnecki P., Jurga S.

Polarisation and energy barriers in ferroelectric pyridinium perchlorate Polycrystalline sample of pyridinium perchlorate was studied by NMR method in the temperature range from 133 to 313 K. Assuming a reorientation of pyridinium cations over inequivalent potential energy barriers in the low-temperature and intermediate phases a temperature dependence of an asymmetry parameter was determined from analysis of 2H line shape. By using the known potential shape and population of its minima, a temperature dependence of the spontaneous polarisation was calculated. The polarisation determined in this way compared with that measured by the pyroelectric effect revealed the mixed type of ferroelectricity in the crystal studied: the order-disorder and displacive one.

Ferroelectrics, 368(1p2), 63-71 (2008)

DOI: 10.1080/00150190802367927   (Pobrane:  2020-07-25)


112.

Kozak M., Kempka M., Szpotkowski K., Jurga S.

NMR in soft materials: A study of DMPC/DHPC bicellar system The DMPC/DHPC bicellar system at the molar ratio of 2.8:1 has been characterised by measurements of self-diffusion coefficient (using PFGSE and PFGSTE NMR sequences), differential scanning calorimetry (DSC) and small angle scattering of synchrotron radiation (SAXS). The DSC curve shows only one endothermic peak characterised by the peak temperature T-peak = 295.7 K and the onset temperature T-onset = 290.1 K. This peak can be assigned to the nematic to smectic phase transition. Below the phase transition temperature, NMR diffusion experiments indicate a two-exponential decay of the spin echo amplitude allowing two diffusion coefficients D, and D-2 to be extracted from the experimental data. The maximum size (D-max) of the bicelle determined from SAXS data using the pair distance distribution function p(r) is 11.2 nm and the bilayer thickness is 5 nm.
(C) 2007 Published by Elsevier B.V.

Journal of Non-Crystalline Solids, 353(47-51), 4246-4251 (2007)

DOI: 10.1016/j.jnoncrysol.2007.02.068   (Pobrane:  2020-10-21)


111.

Kozak M., Domka L., Jurga S.

The effect of selected surfactants on the structure of a bicellar system (DMPC/DHPC) studied by SAXS The stabilizing or disturbing effect of different surfactants on the bicellar phase of phospholipids significantly depends on their type. The effect of different surfactants on the bicellar structure made of a mixture of phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine and 1.2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC/DHPC) has been studied by the small angle scattering of synchrotron radiation. The study has been performed for three surfactants: dodecyldimethyl-(hexyloxymethyl)ammonium chloride, n-undecylammonium chloride and t-octylphenoxypolyethoxyethanol (Triton X-100) introduced into a bicellar solution of DMPC/DHPC (2.8:1). The bicellar phase has been disturbed in the shortest time in the presence of dodecyldimethyl-(hexyloxymethyl)ammonium chloride in this system a transition from the bicellar to lamellar structure has been directly visible. The changes have been less pronounced in the presence of undecylammonium chloride and practically not noted in the presence of Triton X-100.
(C) 2007 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 846(1-3), 108-111 (2007)

DOI: 10.1016/j.molstruc.2007.01.038


110.

Szutkowski K., Stilbs P., Jurga S.

Proton chemical exchange in aqueous solutions of dodecylammonium chloride: Effects of micellar aggregation Proton chemical exchange was studied in aqueous solutions of dodecylammonium chloride (DDAC1) for two selected concentrations, 18 and 33 wt %. The Fourier transform Carr-Pureell-Meiboom-Gill (CPMG) NMR method combined with the Carver and Richards model for T-2 dispersion curve analysis were employed to evaluate the temperature dependence of the proton exchange rates k(ex). An increase of the energy barrier height Delta G double dagger for the proton chemical exchange between water and ammonium cation (-NH3+) was observed as the DDAC1 concentration was increased. Results are complementary to previous studies of aggregation phenomena for various n-alkylammonium chlorides.

Journal of Physical Chemistry C, 111(43), 15613-15619 (2007)

DOI: 10.1021/jp073696s   (Pobrane:  2020-10-23)


109.

Orozbaev B., Fojud Z., Makrocka-Rydzyk M., Schroeder G., Jurga S.

Molecular dynamics of podand studied by broadband dielectric and nuclear magnetic resonance spectroscopies Nuclear magnetic resonance (NMR) and broadband dielectric spectroscopies (BDS) were used toanalyze the molecular dynamics in P10.3H Podand. The temperature studies of NMR line and magnetic spin-lattice relaxation times accompanied by DS investigation enabled us to distinguish three main dynamical processes connected with the motions of the P10.3H Podand chains. In the low-temperature region the magnetic relaxation was associated with fast axial C-3 rotation of methyl groups. Moreover, two other independent processes were observed and interpreted as (i) segmental motion of both oxyethylene and ethylene units, and (ii) the overall motion involved in the melting process.

Macromolecular Chemistry and Physics, 208(19-20), 2121-2127 (2007)

DOI: 10.1002/macp.200700197   (Pobrane:  2008-01-09)


108.

Danch A., Osoba W., Chrobak D., Nowaczyk G., Jurga S.

Alpha(c) relaxation of the constrained amorphous phase : polyethylene-chalk composites The study presents properties of polyethylene commercial products with special attention to properties of a 'semi-ordered' amorphous phase. Although, one can hardly prove the existence of such an interphase, the results description based on the idea of coexistence of two amorphous fractions ('real' and 'semi-ordered') in one system gives a broader understanding of the relationship between product history and morphology of the resultant engineering products. Their supermolecular structures were explored using positron annihilation lifetime spectroscopy (PALS), calorimetry (DSC) and mechanical spectroscopy in a tensile and a torsion mode (DMTA). The stability of these structures is also discussed based on a simple statistical analysis of the thermodynamic and structural parameters. The study exhibited that chalk did not disturb too much the crystalline domains of PE-LD whereas it influenced the interphase. Mechanical study showed that such a product is not stable during long time storage. The comparison with previous results, obtained for PE-carbon black composites, revealed differences in the morphologies and the alpha(c) relaxations of PE chains, observed in the composites including various fillers.

Journal of Thermal Analysis and Calorimetry, 90(1), 201-208 (2007)

DOI: 10.1007/s10973-006-7599-x


107.

Kozak M., Domka L., Jurga S.

Interactions of cationic surfactants with DPPC The effects of different cationic surfactants (n-undecylammonum chloride, UDACl and dodecyldimethyl (dodecyloxymethyl) ammonium chloride, DDMDDACl) on fully hydrated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles have been studied. In the studied systems the molar ratio (x) of DPPC/surfactant ranged between x=0.0164-0.82 and from x=0.0352-1.76 for DPPC/DDMDDACl and DPPC/UDACl, respectively. For both systems, the enthalpy associated with the phase transition significantly decreases even at the lowest surfactant concentration. Also the main phase transition temperature is shifted towards lower temperatures. The structural parameters of the phases have been characterised by small angle X-ray scattering (SAXS). The SAXS results have proved that UDACl at x=0.0352 molar ratio significantly influences the DPPC lamellar structure, while its total disappearance was observed for x=0.176. The presence of DDMDDACl causes a total disappearance of the DPPC lamellar structure already at the lowest molar ratio (x=0.0352). Each surfactant in the system with DDPPC leads to a mixed micellar phase formation.

Journal of Thermal Analysis and Calorimetry, 88(2), 395-399 (2007)

DOI: 10.1007/s10973-006-8061-9


106.

Jasinska L., Balas A., Haponiuk J.T., Nowaczyk G., Jurga S.

Thermal and dynamic mechanical analysis of cross-linked poly(esterurethanes) New cross-linked poly(esterurethanes) (PEU) based on unsaturated olygo(alkyleneester)diol (OAE), 4,4'-diphenylmethane diisocyanate (MDI) and styrene or methyl methacrylate as curing monomers were prepared. The synthesis of PEU was performed in two steps. In the first step OAE was obtained from adipic acid, maleic anhydride and ethylene glycol. In the second step a prepolymer was obtained in a reaction of OAE with different amounts of 4,4'-diphenylmethane diisocyanate followed by crosslinking using previously mentioned curing monomers. The influence of structure of the poly(esterurethanes) on thermal and dynamic mechanical properties is studied. Thermogravimetric analysis shows that cross-linked poly(esterurethanes) demonstrate high thermal stability. Moreover the dynamic mechanical thermal analysis shows that the presence of styrene cross-linking chains in polymers lead to the phase separation in cross-linked poly(esterurethanes).

Journal of Thermal Analysis and Calorimetry, 88(2), 419-423 (2007)

DOI: 10.1007/s10973-006-8033-0


105.

Fojud Z., Herzig P., Żogał O. J., Pietraszko A., Dukhnenko A., Jurga S., Shitsevalova N.

Electric-field-gradient tensor and boron site resolved 11B NMR in single-crystalline YB12 B11 NMR measurements on a single crystal of YB12 have been performed at room temperature at a frequency of 128.4MHz. The electric-field-gradient (EFG) tensor components and the principal axes calculated previously by first-principles methods have been verified experimentally. Three magnetically different boron-atom groups in the B12 cluster were clearly observed for the crystal orientation used in this work. This distinction results from different EFG-tensor orientations with respect to magnetic field and not from different quadrupolar splittings (νQ) or asymmetry-parameter values (η). The magnetically different boron atoms have been identified through the calculated angle dependence of the satellite transitions (0°–360°). Very satisfactory agreement between the calculated and experimental angular dependencies of the EFG tensor has been obtained. Similarly, the quadrupolar splittings and asymmetry parameters agree very well with those previously determined from NMR measurements on a powder sample of YB12.
(C)2007 American Physical Society

Physical Review B - Condensed Matter and Materials Physics, 75(18), 184102 (2007)

DOI: 10.1103/PhysRevB.75.184102   (Pobrane:  2020-10-21)


104.

Kozak M., Domka L., Jurga S.

SAXS study of selected cationic surfactant influence on the DSPC-based model phospholipid system The phase behaviour of lipid bilayer systems prepared with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) with dodecyldimethyl(benzyloxymethyl)ammonium chloride (BzMDDAC) (at concentrations 0.1, 1 and 5%) has been studied by small angle X-ray scattering and differential scanning calorimetry. The SAXS and DSC results of the hydrated 10% DSPC revealed one typical phase transition corresponding to melting of the hydrocarbon chains at 5 5 degrees C. In the system of 10% DSPC - 0.1% BzMDDAC the main transition was somewhat shifted towards lower temperatures, while at 1% concentration of BzMDDAC in the mixture, the lamellar phase disappeared, as evidenced by SAXS and DSC. The increase in BzMDDAC concentration to 5% in the mixture with 10% DSPC resulted in formation of a new lamellar phase.

Solid State Phenomena, 130, 257-262 (2007)

DOI: 10.4028/3-908451-40-x.257   (Pobrane:  2021-01-10)


103.

Wojtyła L., Garnczarska M., Zalewski T., Bednarski W., Ratajczak L., Jurga S.

A comparative study of water distribution, free radical production and activation of antioxidative metabolism in germinating pea seeds The aim of this study was to investigate whether there is a relationship between hydration of the embryo axes and cotyledons and the resumption of the oxidative metabolism in both organs of germinating seeds of pea (Pisum sativum L. cv. Piast). Nuclear magnetic resonance (H-1-NMR) spectroscopy and imaging were used to study temporal and spatial water uptake and distribution in pea seeds. The observations revealed that water penetrates into the seed through the hilum, micropyle and embryo axes, and cotyledons hydrate to different extents. Thus, inhomogeneous water distribution may influence the resumption of oxidative metabolism. Electron paramagnetic resonance (EPR) measurements showed that seed germination was accompanied by the generation of free radicals with g(1) and g(2) values of 2.0032 and 2.0052, respectively. The values of spectroscopic splitting coefficients suggest that they are quinone radicals. The highest content of free radicals was observed in embryo axes immediately after emergence of the radicle. Glutathione content decreased during the entire germination period in both embryo axes and cotyledons. A different profile was observed for ascorbate, with significant increases in embryo axes, coinciding with radicle protrusion. Etectrophoretic analysis showed that superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1)and glutathione reductase (GR, EC 1.6.4.2) were present in dry seeds and were activated later during germination, especially in embryo axes. The presence of all antioxidative enzymes as well as low molecular antioxidants in dry seeds allowed the antioxidative machinery to be active as soon as the enzymes were reactivated by seed imbibition. The observed changes in free radical levels, antioxidant contents and enzymatic activities in embryo axes and cotyledons appear to be more closely related to metabotic and developmental processes associated with preparation for germination, and do not correspond directly to the hydration of the tissues.
(C) 2006 Elsevier GmbH. All rights reserved.

Journal of Plant Physiology, 163(12), 1207-1220 (2006)

DOI: 10.1016/j.jplph.2006.06.014   (Pobrane:  2020-10-21)


102.

Kozak M., Domka L., Foltynowicz Z., Jakubiak P., Jurga S.

Studies on the structure of polyethylene-modified bentonite nanocomposites LDPE modified with vinyltriethoxysilane and lactic acid and a natural bentonite organophilized with hexadecyltrimethylammonium bromide were used to extrude biodegradable nanocomposites contg. 4% bentonite and 30% lactic acid. Elongation-at-break and stretching strength were improved by 29% and 12% as compared with the starting composites. Microstructure examn. showed the polymer matrix to be more compact with the nanofiller added. The m.p. and the m. enthalpy of the nanocomposite were 114.7 degrees C (higher by 2 degrees C) and -134.2 J/g (higher by similar to 10 degrees/6), resp.

Przemysł Chemiczny, 85(8-9), 840-843 (2006)


101.

Krzaczkowska J., Szcześniak E., Jurga S.

Phase behaviour of dipalmitoylphosphatidylcholine/surfactant/water systems studied by infrared spectroscopy Phospholipids are the most important components of membranes taking part in stabilization of the functional structure of biological cells. The main aim of the present study is to determine the influence of selected antimicrobial surfactants on the phospholipids structure. The water solutions of dipalmitoylphosphatidylcholine (DPPC) in the presence of two quaternary ammonium surfactants: dodecyidimethyl(hexyloxymethyl)ammonium chloride (HMDDAC) and (decyloloxymethyl)dodecydimethylammonium chloride (DMDDAC) were studied using FTIR spectroscopy. The thermal behaviour of these systems was analyzed using spectral parameters of CH2 and C=O vibrations bands. We have observed a lowering of temperature corresponding to the main phase transition of the surfactant/DPPC systems due to disordering of the phospholipids structure by the surfactants and phospholipids interaction.
(C) 2006 Published by Elsevier B.V.

Journal of Molecular Structure, 794(1-3), 168-172 (2006)

DOI: 10.1016/j.molstruc.2006.02.003   (Pobrane:  2020-10-21)


100.

Nozirov F., Nazirov A., Jurga S., Fu R.

Molecular dynamics of poly(L-lactide) biopolymer studied by wide-line solid-state 1H and 2H NMR spectroscopy The molecular dynamics of poly(L-lactide) (PLLA) biopolytner was characterized through analyses of H-1 and H-2 NMR line-shapes and spin-lattice relaxation times at different temperatures. At low temperatures (e.g. 90K), the methyl group rotation is dominant leading to a significant reduction in the proton second moment. Fast methyl group reorientation occurs at ca. 130 K. In additional to the fast methyl group rotation, hydroxyl groups start to reorient as the temperature increases further, eventually leading to the breakdown of the segments of the biopolymer chains above its glass transition temperature Tg of 323K. The analyses of the H-2 NMR line-shapes indicate that both the methyl and hydroxyl reorientations can be described by the so-called cone model, in which the former has three equilibrium positions with theta(C-D) = 70.5 degrees and phi = 120 degrees while the latter one exhibits two equilibrium positions with theta(C-D) = 78 degrees and phi = 180 degrees.
(C) 2005 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 29(4), 258-266 (2006)

DOI: 10.1016/j.ssnmr.2005.09.001   (Pobrane:  2020-10-21)


99.

Szutkowska L., Peplińska B., Jurga S.

Molecular dynamics of tert-butyl chloride confined to CPG (7.4, 15.6 nm) The paper complements our earlier NMR investigation of molecular dynamics of tert-butyl chloride restricted by geometries of the type MCM-41 and CPG by the new sizes of CPG and by differential scanning calorimetry method. We report proton and deuteron NMR lineshapes and the spin-lattice relaxation results of tert-butyl chloride in CPG of the 15.6 nm and 7.4 nm pore diameter in the temperature range 70 K

Acta Physica Polonica A, 108(2), 357-370 (2005)

DOI: 10.12693/APhysPolA.108.357
WWW: http://przyrbwn.icm.edu.pl/APP/PDF/108/a108z218.pdf   (Pobrane:  2021-01-10)


98.

Makrocka-Rydzyk M., Orozbaev B., Nowaczyk G., Głowinkowski S., Jurga S.

Molecular dynamics in cyclic olefin copolymer Nuclear magnetic resonance, broadband dielectric spectroscopy and dynamic-mechanical thermal analysis were employed to study molecular dynamics of ethylene-norbornene copolymer. The analysis of experimental data indicates existence of three motional processes denoted as α, β, and γ in order of decreasing temperature. The α relaxation is related to the dynamic glass transition, while the beta relaxation, observed only for the untreated sample, is assigned to short range segmental motions involving norbornene units. The γ relaxation is due to very local motions of ethylene units e.g. trans-gauche isomerization, similar to those responsible for γ relaxation in polyethylene. The rate of motion accountable for γ process, follows the Vogel-Fulcher-Tammann equation, similarly to alpha transition, indicating cooperative nature of the motion.

Acta Physica Polonica A, 108(2), 385 (2005)

DOI: 10.12693/APhysPolA.108.385
WWW: http://przyrbwn.icm.edu.pl/APP/PDF/108/a108z221.pdf   (Pobrane:  2021-01-10)


97.

Dobies M., Kuśmia S., Jurga S.

1H NMR and rheological studies of the calcium induced gelation process in aqueous low methoxyl pectin solutions The H-1 NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheometry have been applied to study the ionic gelation of 1% w/w aqueous low methoxyl pectin solution induced by divalent Ca2+ cations from a calcium chloride solution. The model-free approach to the analysis of H-1 NMR relaxometry data has been used to separate the information on the static (β) and dynamic (<τ(c)>) behaviour of the systems tested. The H-1 NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (β, <τ(c)> and T-2 vs. CaCl2 concentration) is consistent with the two-stage gelation process of low methoxyl pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl2) is followed by the appearance of weak inter-dimer aggregations (for CaCl2 >= 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl2 has been confirmed by rheological measurements. Apart from that, the T1 and T2 relaxation times have been found to be highly sensitive to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability.

Acta Physica Polonica A, 108(1), 33 (2005)

DOI: 10.12693/APhysPolA.108.33
WWW: http://przyrbwn.icm.edu.pl/APP/PDF/108/a108z104.pdf   (Pobrane:  2021-01-10)


96.

Krzaczkowska J., Fojud Z., Kozak M., Jurga S.

Spectroscopic studies of poly(epsilon-caprolactone)/sodium montmorillonite nanocomposites Polymer-layered silicate nanocomposites belong to a new class of hybrid materials consisting of organic-synthetic polymer matrix and inorganic filler-layered structure clay minerals. The paper presents the results of FTIR, NMR, and SAXS studies of poly( epsilon -caprolactone)/sodium montmorillonite nanocomposites. We observed a correlation between the concentration of poly( epsilon -caprolactone) in nanocomposite samples and structural changes both of the clay mineral and the intercalated polymer. Stiffening of the clay structure appears as a result of poly(epsilon -caprolactone) intercalation into a clay structure. 27Al NMR studies indicated in nanocomposites two non-equivalent sites of aluminium ions, i.e. in octahedral and tetrahedral coordination, whereas in the montmorillonite clay structure the aluminium ions are located in the interlayer space too. We found also that the temperatures of structural changes and softening process of poly( epsilon-caprolactone) chains in the nanocomposites depend on the concentration of poly( epsiv -caprolactone).

Acta Physica Polonica A, 108(1), 187-196 (2005)

DOI: 10.12693/APhysPolA.108.187
WWW: http://przyrbwn.icm.edu.pl/APP/PDF/108/a108z124.pdf   (Pobrane:  2021-01-10)


95.

Lubas M., Sitarz M., Fojud Z., Jurga S.

Structure of multicomponent SiO2-Al2O3-Fe2O3-CaO-MgO glasses for the preparation of fibrous insulating materials Glasses used for the fabrication of fibrous insulating materials are made from natural raw materials, mainly basalts. Basalt alloys, however, show relatively high crystallization capability, which is disadvantageous for throwing and durability of the fibres prepared. In the work new raw materials, such as melaphyres and diabase from the Silesia region of Poland were applied for the preparation of aluminosilicate alloys. In order to study their crystallization ability the glasses were heated in an electric furnace at various temperatures for various time periods. Depending on the raw material used as well as the temperature of heat-treatment amorphous or crystalline materials were obtained. Crystalline phases were identified based on X-ray diffraction studies. It was found that magnetite/titanomagnetite crystallized in the first step. Then pyroxenes phases of diopsides or augite type appeared in the systems. Spectroscopic investigations in the mid IR region were carried out for all the glasses. This made it possible to determine the influence of thermal treatment on the structural changes of glasses (changes in the spectra shapes). Locations of the bands due to Al-O-Si and Si-O-Si bridges vibrations suggested that in most cases the augite-type phases were present in the systems (aluminium coordination number equal to 4 and 6). Appearance of aluminium in coordination 4 and 6 was confirmed by NMR investigations (two clear bands in the spectra).
(C) 2004 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 744-747, 615-619 (2005)

DOI: 10.1016/j.molstruc.2004.12.011   (Pobrane:  2020-10-21)


94.

Sitarz M., Handke M., Fojud Z., Jurga S.

Spectroscopic studies of glassy phospho-silicate materials The aim of the work is to determine the internal structure of bioactive glasses based on structural studies. Due to the absence of the long-range order, the X-ray methods usually applied in the studies of crystalline materials are of low applicability in the investigations of glasses. Therefore, spectroscopic methods, such as IR and NMR, which make it possible to 'see' the short- and the middle-range order are extremely suitable in their studies. IR investigations have shown that the glasses studied exhibit non-uniform domain composition, which should facilitate their transformation into glass-crystalline state. Additionally, detailed NMR measurements have been carried out in order to determine the influence of glass structure on the course of its crystallization. These studies make it possible to verify the common opinions on the middle-range order (domains) in the glasses studied. The results obtained for Al-27 and P-31 are particularly promising. Changes in the environment Of [SiO4](4-) tetrahedra, which can be spatially connected with various numbers Of [PO4](3-) and [AlO4](5-) tetrahedra cause the presence of various types of bridging bonds, such as Si-O-Si, Si-O-Al and Si-O-P. This in turn has significant impact on the number and the shape of the bands occurring in the spectra.
(C) 2005 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 744-747, 621-626 (2005)

DOI: 10.1016/j.molstruc.2004.12.050   (Pobrane:  2020-10-23)


93.

Łodziński M., Sitarz M., Stec K., Kozanecki M., Fojud Z., Jurga S.

ICP, IR, Raman, NMR investigations of beryls from pegmatites of the Sudety Mts Detailed ICP, IR, Raman and NMR investigation were performed for more than 50 samples of beryls from pegmatites in the Sudety Mts. MIR spectra were measured at room (293 K), low up to 22 K and high up to 1273 K temperatures. The absorption bands for studied samples of beryl are correlated with chemical composition and structural parameters. The samples represent both alkali-poor (potassium-bearing, sodium-potassium-bearing) and alkali-rich (sodic and sodic-lithian) members of the beryl group. Two types of H2O molecules are discerned in all studied beryls. The I-type is not connected with alkali with bands at 3697/3690 cm(-1), 3647/3630/3610 cm(-1) (3606 cm(-1) in Raman spectra) and 1602/1550 cm(-1) dominates over the II-type (hydrated anions of alkali) with bands at 3660 cm(-1), 3592/3590 cm(-1) (3597 cm(-1) in Raman spectra) and 1637/1630cm(-1). CO2 molecules (2360 cm(-1) in MIR spectra, 1386 cm(-1), 1240 cm(-1) in Raman spectra) and hydroxyl groups in subordinate quantities occur in structural channels of beryls, except for mentioned above. Main bands in the range of 1200-400 cm(-1) are diagnostic in discerning of the three types of beryls according to lattice parameter classification. Studied beryls, in the most cases, belong to normal-type. Some samples are octahedral-type, and do not occur tetrahedral beryls in the Sudety Mts.
(C) 2005 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 744-747, 1005-1015 (2005)

DOI: 10.1016/j.molstruc.2004.12.042   (Pobrane:  2020-10-21)


92.

Olek M., Kempa K., Jurga S., Giersig M.

Nanomechanical properties of silica-coated multiwall carbon nanotubes-poly(methyl methacrylate) composites The mechanical properties of polymer composites, reinforced with silica-coated multiwall carbon nanotubes (MWNTs), have been studied using the nanoindentation technique. The hardness and the Young's modulus have been found to increase strongly with the increasing content of these nanotubes in the polymer matrix. Similar experiments conducted on thin films containing MWNTs, but without a silica shell, revealed that the presence of these nanotubes does not affect the nanomechanical properties of the composites. While carbon nanotubes (CNTs) have a very high tensile strength due to the nanotube stiffness, composites fabricated with CNTs may exhibit inferior toughness. The silica shell on the surface of a nanotube enhances its stiffness and rigidity. Our composites, at 4 wt % of the silica-coated MWNTs, display a maximum hardness of 120 ± 20 MPa, and a Young's modulus of 9 ± 1 GPa. These are respectively 2 and 3 times higher than those for the polymeric matrix. Here, we describe a method for the silica coating of MWNTs. This is a simple and efficient technique, adaptable to large-scale production, and might lead to new advanced polymer based materials, with very high axial and bending strength.

Langmuir, 21(7), 3146-3152 (2005)

DOI: 10.1021/la0470784


91.

Kozak M., Jurga S.

SAXS study of lipid bilayer model systems. The phase diagram of n-undecylammonium chloride/water system Alkylammonium halides belong to cationic surfactants. In water solutions they can form bilayer systems whose properties mimic those of the lipid membranes. The n-undecylammonium chloride (C11H23NH3Cl; UDACl)/water system was studied by small angle X-ray scattering (SAXS) at the concentrations of UDACl from 15 to 70% and in temperature range from 20 to 70 ºC. The results permitted our drawing a fragment of phase diagram for this system. Three main phases: isotropic, lamellar and hexagonal were observed and characterized

Fibres and Textiles in Eastern Europe, 13(5), 93-95 (2005)

WWW: http://www.fibtex.lodz.pl/53_22_93.pdf


90.

Trejda M., Lazar K., Decyk P., Fojud Z., Jurga S., Ziółek M.

Generation of iron active species in MCM-41 materials A new method, the immobilisation or ferroceneacetic acid (FAA) on various MCM-41 mesoporous molecular sieves (containing Si or Si+Al) followed by calcination at 773 K has been applied for the formation of iron active species. The structural, surface and catalytic properties of these materials, characterised by N-2 adsorption/desorption, XRD, Al-27 NMR, ESR, and Mossbauer spectroscopy as well as test reactions, were compared with those of materials prepared via commonly used impregnation methods. Contrary to Fe-impregnated samples, Fe oxides species were only slightly detected in the solids modified by FAA followed by calcination. It is evidenced that the new technique applied for Fe-modification gives rise to the significantly higher activity (in isopropanol decomposition and acetonylacetone cyclization) reached thanks to a better isolation and/or dispersion of Fe3+ species. The presence of Al in the sample influences the Fe3+ reduction under vacuum.

Studies in Surface Science and Catalysis A, 158 A, 829-836 (2005)

DOI: 10.1016/s0167-2991(05)80419-7   (Pobrane:  2021-01-02)


89.

Wołoszczuk S., Banaszak M., Jurga S., Pakuła T., Radosz M.

Low-temperature ordering effects in diblock copolymer melts from lattice simulation A lattice simulation of a model diblock copolymer melt is presented. In a series of simulation experiments an 8-8 diblock melt is quenched from an athermal state to 47 lower temperatures. A set of simulation boxes, 30x32x30, 40x32x60, 50x32x30, and 60x32x30, is used in order to explore the size effects. Energy, specific heat, copolymer end-to-end distance, lamellar spacing, and the degree of interfacial ordering are reported. For all sizes considered, the low-temperature interfacial ordering is noticeable.
(C) 2004 American Institute of Physics.

Journal of Chemical Physics, 121(23), 12044-12049 (2004)

DOI: 10.1063/1.1812751   (Pobrane:  2020-10-21)


88.

Danch A., Sułkowski W.W, Moczyński M., Radon A., Stelzer F., Jurga S.

Structural relaxation and morphology of the rubber-urethane composites The supermolecular structures and structural relaxation of the waste rubber-urethane composites are discussed on the basis of results of calorimetric measurements and mechanical spectroscopy. The results give a broader understanding of the relationship between processing history and morphology in the resultant engineering products. The effect of different kinds of urethane prepolymer on the thermomechanical properties of commercial composite products is presented. The idea of reaction between rubber granulate and urethane prepolymer is under consideration. The shear and tensile modes were applied to better explore relaxations that occur in rubber grains and in an interphase area created by the urethane agents. The rubber waste management problem was taken into account also.
(C) 2004 Wiley Periodicals, Inc.

Journal of Applied Polymer Science, 94(3), 1186-1193 (2004)

DOI: 10.1002/app.21027   (Pobrane:  2020-10-21)


87.

Olek M., Ostrander J., Jurga S., Mohwald H., Kotov N., Kempa K., Giersig M.

Layer-by-layer assembled composites from multiwall carbon nanotubes with different morphologies We report formation of polyelectrolyte/multiwall carbon nanotube (MWNT) multilayers; by the layer-by-layer assembly technique. Both "hollow" and "bamboo" type MWNTs were employed. Scanning electron and atomic force microscopy indicate high structural homogeneity of the prepared composites. Ellipsometry and the absorbance spectroscopy confirm sequential adsorption of oppositely charged nanotubes and the polyelectrolyte resulting in uniform growth of the polyelectrolyte/MWNT films. Measurements of the mechanical properties show that these are strong composite hybrid films with mechanical properties exceeding many carbon nanotube composites made by mixing, or in-situ polymerization. Bamboo-type carbon nanotube composites display ultimate tensile strength of 150 ± 35 MPa and Young modulus of 4.5 ± -0.8 GPa as compared to 110 ± 25 MPa and 2 ± 0.5 GPa in composites made from common hollow MWNTs. This indicates that the morphology of the fibers can substantially improve matrix connectivity on the material mitigating "telescopic effect" in MWNTs. The films made from bamboo-type MWNTs approach in strength recently reported layer-by layer composite films from single wall carbon nanotubes, while being substantially less expensive. These results confirm the potential of the layering method for the manufacturing of composites with high load of strong filler and importance of uniform distribution and good interconnectivity between carbon nanotubes and the polymer matrix.

Nano Letters, 4(10), 1889-1895 (2004)

DOI: 10.1021/nl048950w


86.

Wachowicz M., Jurga S., Vilfan M.

Collective and local molecular dynamics in the lyotropic mesophases of decylammonium chloride: 1H and 2H NMR study The collective and individual dynamics of decylammonium chloride (DACl) molecules in water environment were investigated as a function of surfactant concentration and temperature. In the presence of water the DACl forms a variety of self-assembled structures, ranging from isotropic micellar systems to lyotropic liquid crystalline phases of hexagonal, nematic, and lamellar types. In order to characterize the complex molecular dynamics that occur in the DACl-water system, we applied H-1 and H-2 NMR techniques that cover the whole frequency range between 1 kHz and 30 MHz. The slow molecular dynamics were studied by H-1 NMR fast-field-cycling T-1 measurements and pulse-frequency dependence of H-2 NMR transverse relaxation time, performed by means of the Carr-Purcell-Meiboom-Gill sequence. We detected a well-expressed contribution of order director fluctuations, i.e., layer undulations, with characteristic omega(L)(-1) frequency dependence of T-1(-1) in the lamellar phase. Its presence indicates a relatively weak impact of interactions between neighboring DACl layers. The frequency dependence of proton T-1(-1) in the hexagonal phase exhibits a different type of frequency dispersion, T(1)(-1)similar toomega(L)(-1.32). The increase in the exponent is explained with the quasi-one-dimensional character of fluctuations in elongated cylinders. Further, the T-1 and T-2 relaxation times of deuterons selectively attached to the C2 and C7 segments of the hydrocarbon chains of DACl were measured at a Larmor frequency of 30.7 MHz, providing quantitative information about local molecular dynamics.

Physical Review E - Statistical, Nonlinear and Soft Matter Physics, 70, 031701 (2004)

DOI: 10.1103/PhysRevE.70.031701   (Pobrane:  2020-10-23)


85.

Gnatyuk I., Puchkovska G., Chashechnikova I., Nozirov F., Jurga S., Peplińska B.

1H NMR study of hydrogen bonding and molecular dynamics of 5CB confined to molecular sieves It has been found that the main mechanism of H-1 protons spin-lattice relaxation of bulk 5CB at 200 MHz is its intramolecular motion, namely, the reorientation of CH2 and CH3 groups of its alkyl chain. Activation parameters of such motions have been estimated. Drastic decrease in proton spin-lattice relaxation times at the nematic-to-isotropic phase transition can be explained by the activation of molecular translational diffusion and reorientations around long and short molecular axes of bulk 5CB. Our NMR analysis revealed the slowing-down of molecular dynamics of confined 5CB molecules and their fragments. This can be explained by the interaction of some part of 5CB molecules with the surface active Si(Al)-OH centers of MCM matrix via hydrogen bonds of Si(Al)-(OHN)-N-... drop C-type.
(C) 2004 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 700(1-3), 183-189 (2004)

DOI: 10.1016/j.molstruc.2004.01.048   (Pobrane:  2020-10-21)


84.

Kozak M., Foltynowicz Z., Jakubiak P., Fojud Z., Domka L., Jurga S.

Preparation and structural study of the composites of polyethylene with modified bentonite The paper reports a study on obtaining and characterisation of organophilised bentonite. Modification of the bentonite studied has been confirmed by SEM, XRD and NMR results. The organoplilised filler has been used for preparation on nanocomposites based on polyethylene or polyethylene modified with vinyltriethoxysilane and lactic acid. The best mechanical parameters have been obtained for the composites on the basis of the modified polyethylene containing 4% of organophilised bentonite and 50% of lactic acid.

Mat. VI Konferencji Naukowo-Technicznej "Polimery i Kompozyty Konstrukcyjne", , 69-74 (2004)

   (Pobrane:  2021-01-08)


83.

Gnatyuk I., Galdyna O., Chashechnikova I., Nozirov F., Jurga S., Peplińska B.

1H NMR spectra of 5CB liquid crystal and 5CB-MCM heterogeneous system It is shown that, in the 1H NMR spectra of 5CB, the splitting of proton bands is the result of the dipole-dipole interaction. Using the value of the splitting of the 1H bands, we determined the order parameters S for some fragments of 5CB molecules in the nematic phase. It is found that the values of S for the biphenyl core are twice greater than that for alkyl radical, which is the evidence for different dynamics of these structure fragments. From the analysis of the form of bands in the 1H spectra in the hetereogeneous system 5CB-MCM, we showed that, in the temperature range of the existence of the nematic and crystal phases of bulk 5CB, there is no ordering of these molecules in the channels of MCM. This is caused by the appearance of defects in the liquid crystal ordering due to the interaction of some part of the LC molecules with the active centers of the surface of MCM channels.

Proceedings of SPIE - XVI International Conference on Spectroscopy of Molecules and Crystals, 5507, (2004)

DOI: 10.1117/12.569807
ISBN: 9780819454447   (Pobrane:  2021-01-11)


82.

Wachowicz M., Wolak_J., Gracz H., Stejskal E.O., Jurga S., McCord E.F., White J.L.

Length scales which perturb chain packing in amorphous polymers Direct spectroscopic probes of individual chain conformation and free volume are used to measure the increasing perturbation in the local glass-transition temperature of one polymer chain with decreasing length scale of mixing in binary polyolefin blends. Solid-state 2H and 129Xe NMR experiments reveal a compositional miscibility window in side-chain concentration for polyisobutylene (PIB)/poly- (ethylene-co-butene) (PEB) blends. A combination of pulsed-field gradient and chemical shift data for xenon gas absorbed in these polymer blends indicates that the presence of polymer chains within a radius of ~35 nm of a different chain structure will perturb the intermolecular packing contribution to the total conformational energy of that chain, thereby changing its Tg

Macromolecules, 37(12), 4573-4579 (2004)

DOI: 10.1021/ma049263u   (Pobrane:  2020-08-10)


81.

Kuroczycki B., Banaszak M., Jurga S.

Radial distribution fuctions and compressibility factors for binary mixture of hard spheres from molecular dynamics simulation Molecular dynamics simulation of binary mixtures of hard spheres with large size ratio is reported. Radial distribution functions, their contact values and the compressibility factors are recorded at three state points. A reasonably good agreement with theory and Monte Carlo simulations is shown.

Computational Methods in Science and Technology, 10(2), 161-167 (2004)

DOI: 10.12921_cmst.2004.10.02.161-167
WWW: http://cmst.eu/wp-content/uploads/files/10.12921_cmst.2004.10.02.161-167_Kuroczycki.pdf   (Pobrane:  2020-10-23)


80.

Wołoszczuk S., Banaszak M., Jurga S., Radosz M.

Low-temperature extra ordering effects in symmetric block copolymers from lattice monte carlo simulation Lattice computer simulations of block copolymer melts are reported. Low-temperature lamellar ordering conjecture is presented and its justification is provided. In addition to reviewing the previous data we present a new evidence for the extra ordering effects by recording the mean squared rotational angles as a function of the reduced temperature.

Computational Methods in Science and Technology, 10(2), 219-228 (2004)

DOI: 10.1292/cmst.2004.10.02.219-228
WWW: http://cmst.eu/wp-content/uploads/files/10.12921_cmst.2004.10.02.219-228_Woloszczuk.pdf


79.

Kozak M., Danch A., Osoba W., Domka L., Stelzer F., Jurga S.

Relationship between filler loading and morphology of the interphase in polyethylene-chalk composites Mineral fillers such as kaolin or chalk have been commonly used in the polymer industry as additives to improve polymer mechanical properties and, at the same time, reduce the cost of raw materials. The problem is that the hydrophilic surface of the filler hinders its introduction into the polymer matrix. The paper reports a study of low density polyethylene (LDPE) composites with a natural chalk content of up to 40% wt. The morphology of the filler molecules and the microstructure of the composites were determined by scanning electron microscopy (SEM). The distribution of the filler molecules was estimated by light scattering. The mean diameter of the filler particles was 926.3 nm and their polydispersity was 0.101. The thermal and mechanical properties of the composites were characterised by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The enthalpy of melting, DeltaH(m)*, decreased by about 8% when the amount of filler was 10 wt% in the sample (PE10). However, no difference was recorded between the DeltaH(m) value of the sample with 40 wt% content of filler (PE40), and the value for PE10. In LDPE composites with 40% of chalk,the free space in the interphase is reduced, slightly increasing the chain mobility in comparison with that in the composite with 10% of chalk.

Polymers and Polymer Composites, 12(5), 409-416 (2004)

DOI: 10.1177/096739110401200505   (Pobrane:  2021-01-10)


78.

Kiersnowski A., Kozak M., Jurga S., Pigłowski J.

Structure and crystallization behaviour of poly(epsilon-caprolactone)/clay intercalated nanocomposites Nanocomposites of poly(epsilon-caprolactone)/M-HTAB were obtained by polymerization of caprolactone with various amounts (10, 30, 50 and 64 weight ratio) of montmorillonite organophilized with hexadecyltrimethylammonium bromide (HTAB). The microstructure of nanocomposites was studied by small angle X-ray scattering (SAXS). Additionally, the melting enthalpies (DeltaH(m)), the crystallinities and the half-time of isothermal crystallization were evaluated by differential scanning calorimetry (DSC). As a result of SAXS experiments for the composite PCL/M-HTAB 90/10, in the temperature range from 313 to 283 K, a rapid change in the interlamellar distance from 3.1 nm to 2.72 nm was observed. Similar scattering curves were obtained for the nanocomposite PCL/M-HTAB 70/30. In the composites containing 50% and 64% wt of M-HTAB, the decrease in interlayer distance was less pronounced in the same temperature range (d(001) 3.15 - 3.2 nm). DSC results clearly showed that the crystallization is divided into two separate processes: primary crystallization in the PCL matrix, and secondary crystallization.

Polymers and Polymer Composites, 12(8), 727-737 (2004)

DOI: 10.1177/096739110401200809   (Pobrane:  2021-01-10)


77.

Głowinkowski S., Peplińska B., Jurga S.

Molecular dynamics in solid pyridoxine as studied by 1H NMR Spin-lattice relaxation times T-1 and T-1d as well as NMR second moment were employed to study molecular dynamics of pyridoxine (vitamin 136) in the temperature range 10-350 K. The T-1 minimum observed at low temperatures at 200 MHz is attributed to a motion of methyl group. The motion is interpreted in terms of Haupt's theory, which takes into account the tunneling assisted relaxation. At low temperatures, where T-1 is temperature independent, occupation of the ground state only is assumed. A motion of proton of the hydroxyl groups or CH2OH groups probably provides additional mechanism of relaxation, in the high-temperature region.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 1-4 (2004)

DOI: 10.1016/j.ssnmr.2003.03.025   (Pobrane:  2021-01-21)


76.

Kuśmia S., Kozak M., Szcześniak E., Domka L., Jurga S.

Studies of water penetration into LDPE-calcium lactate composite Penetration of water into low-density polyethylene-calcium lactate composite is studied with NMR techniques. The presence of filler speeds up the water uptake by the polymer matrix and facilitates polyethylene degradation. Spatial distribution of absorbed water molecules within the composite visualised with MRI corroborates differences in dynamical behaviour of the absorbed water molecules revealed by T-2 measurements.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 173-176 (2004)

DOI: 10.1016/j.ssnmr.2003.03.027   (Pobrane:  2020-10-21)


75.

Wasyluk L., Peplińska B., Jurga S.

Molecular dynamics of tert-butyl chloride in CPG studied by NMR The molecular dynamics of tert-butyl chloride (TBC) confined to Controlled Pore Glass matrices of 25 and 7.5 nm were investigated by measuring NMR linewidths, lineshapes, and H-1 and H-2 spin-lattice relaxation times. The behaviour of confined TBC can be explained assuming that the guest molecules form two distinct phases; the surface-affected phase, composed of molecules located at the pore surface, and the bulk-like phase located at the centre of the pores. The bulk-like component of confined TBC, at the temperatures corresponding to the phase III, is characterized by two dynamically different subphases.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 177-184 (2004)

DOI: 10.1016/j.ssnmr.2003.03.028   (Pobrane:  2020-10-21)


74.

Dobies M., Kozak M., Jurga S.

Studies of gelation process investigated by fast field cycling relaxometry and dynamical rheology: the case of aqueous low methoxyl pectin solution The Fast Field Cycling Relaxometry and the dynamical rheology were applied to study the gelation process in aqueous low methoxyl pectin solution in the presence of divalent cations from the calcium chloride. The model-free approach to the analysis of H-1 NMRD data was used to separate the information on the static and dynamic behaviour of the system provided by the dispersion profiles of the systems tested. Mechanical spectroscopy was applied as a complementary method to probe the network formation. The structural changes were most pronounced for the concentration of calcium chloride between 10 and 15 mM (the static parameter beta was found to vary from 0.936 x 10(7) to 1.27 x 10(7) 1/s(2)) revealing the sol-gel transition on visual inspection. The presence of the gel network was confirmed by the rheological measurements. All mechanical spectra exhibited the gel like character, and the solid like response was more evident at higher concentrations of calcium cations. The mean correlation time increased with increasing salt concentration, but remained unchanged for the concentrations above 15 mM. The dynamical changes were most significant at the phase transition from the sol to the gel state.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 188-193 (2004)

DOI: 10.1016/j.ssnmr.2003.03.019   (Pobrane:  2020-10-21)


73.

Nowaczyk G., Głowinkowski S., Jurga S.

Rheological and NMR studies of polyethylene/calcium carbonate composites Rheometry, C-13 CP/MAS NMR spectra and H-1 spin-lattice relaxation times T, and Tip have been employed to study the structure and molecular dynamics in composites of polyethylene (LDPE) with calcium carbonate filler. It has been found that the addition of the filler into the polymer leads to an increase in composite rigidity and a decrease in mobility in its crystalline regions. The presence of the filler affects the crystallization process making the crystal structure less perfect and reduces the size of the crystallites.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 194-199 (2004)

DOI: 10.1016/j.ssnmr.2003.07.003   (Pobrane:  2020-10-21)


72.

Fojud Z., Szcześniak E., Jurga S., Stapf S., Kimmich R.

Molecular dynamics of n-dodecylammonium chloride in aqueous solutions investigated by 2H NMR and 1H NMR relaxometry Molecular dynamics in n-dodecylammonium chloride/water solutions for concentrations of 34 and 45wt% was studied by 2 H NMR and by H-1 NMR dispersion of spin-lattice relaxation in the 2 kHz-90 MHz frequency range. The system exhibits a number of lyotropic liquid crystalline phases, which differ in symmetry and involve motions characterized by a wide frequency scale. The analysis of H-2 NMR lineshapes of selectively deuterated DDACl molecules gave us an evidence for local trans-gauche conformational changes in the chains, whereas the dispersion of spin-lattice relaxation times T, explored by fast field cycling method revealed fast local motions, translational diffusion and collective molecular dynamics of the chains. In particular, we have found that the order director fluctuation mechanism in smectic and nematic phases dominates spin-lattice relaxation below I MHz and that local motions and translational diffusion are responsible for the spin-lattice relaxation in the higher Larmor frequency range.
(C) 2003 Elsevier Inc. All rights reserved.

Solid State Nuclear Magnetic Resonance, 25(1-3), 200-206 (2004)

DOI: 10.1016/j.ssnmr.2003.07.002   (Pobrane:  2020-10-21)


71.

Banaszak M., Wołoszczuk S., Jurga S., Pakuła T.

Lamellar ordering in computer-simulated block-copolymer melts by a variety of thermal treatments A lattice computer simulation of a symmetric A-B-A triblock copolymer melt is reported. This melt is quenched, in simulation, from an athermal state to 39 different temperatures using cooperative motion algorithm. Energy, specific heat, copolymer end-to-end distance, bridging fraction, lamellar spacing, concentration profiles, and microstructure visualizations are reported. The quenching simulation results are compared with those obtained by alternative thermal treatments, that is by slow heating and slow cooling. Quenches yield data consistent with theory and experiment, whereas slow cooling and slow heating results do not capture the expected behavior for the lamellar spacing and the bridging fraction. Finally, at very low temperatures, below the conventional order-disorder transition temperature, an additional ordering is recorded, from a conventional lamellar phase to a lamellar structure showing copolymer junction points condensed into a two-dimensional plane.
(C) 2003 American Institute of Physics.

Journal of Chemical Physics, 119(21), 11451-11457 (2003)

DOI: 10.1063/1.1622375   (Pobrane:  2020-10-21)


70.

Wolak_J., Jia X., Gracz H., Stejskal E.O., White J.L., Wachowicz M., Jurga S.

Polyolefin miscibility: solid-state NMR investigation of phase behaviour in saturated hydrocarbon blends Chain-level mixing in polyolefins is investigated for blends of polyisobutylene (PIB) and polyethylene-co-1-butene (PEB). Previous reports suggest that PIB exhibits unusual mixing behavior in certain saturated blends relative to other polyolefins, even though it is immiscible with most. Variable-temperature H-1, H-2, C-13, and Xe-129 NMR experiments are used to characterize local PIB chain dynamics in blends with PEB in which the concentration of 1-butene comonomer units is 23 or 66 wt %. Results from 1D and 2D solid-state C-13 exchange experiments, H-1 relaxation measurements, and H-2 line shape analysis indicate that local conformational dynamics of the PIB CH2 group in the polymer backbone increase significantly in blends with PEB copolymers containing 66 wt % butene comonomer (PEB-66). Even though the PEB-66 is a higher Tg polymer than PIB, PIB exhibits a lower effective Tg when the blend is formed relative to its pure state. Similar perturbations are not observed in the PIB/PEB-23 blend, indicating that this blend is not miscible at the chain level. These results are directly relevant to the length scale of glass transitions in polyolefins, indicating that local interchain packing plays an important role in the conformational dynamics that occur within a chain, and are suggestive of local configurational entropy contributions to mixing. Although H-1 spin-diffusion experiments could not reveal quantitative length scales of mixing in the these blends due to insufficient contrast between the constituents, Xe-129 NMR experiments showed that the PIB/PEB-66 blend was homogeneous on a 50 nm length scale. In agreement with the heterogeneous morphology indicated by the dynamic NMR experiments, Xe-129 NMR showed two resolved peaks for the PIB/PEB-23 blend, indicative of phase separation on a 50 nm length scale. The compilation of all the data, most of which was obtained at natural abundance, indicates that the PIB/PEB-66 blend exhibits intimate chain-level mixing on a length scale much shorter than R-g (ca. 8 nm). More importantly, the data show that reduced chain packing constraints occur in the miscible blend and suggest that local entropic contributions are the driving force for miscibility.

Macromolecules, 36(13), 4844-4850 (2003)

DOI: 10.1021/ma0301449   (Pobrane:  2020-08-10)


69.

Fojud Z., Goc R., Kozak A., Jurga S., Wąsicki J.

Polarisation and energy barriers in ferroelectric pyridinium tetrafluoroborate The measurements of 1H and 19F NMR second moment were performed for a polycrystalline sample of (PyH)BF4, whereas the shape of 2H NMR line was analysed for a polycrystalline sample of (d5PyH)BF4. Asymmetry parameter D has been calculated for four models of pyridinium cation reorientation among inequivalent potential energy minima, using experimental value of 1H NMR second moment as well as the 2H NMR line width. Knowing the potential shape and the population of its minima the temperature dependence of polarisation for all the models has been found. From the comparison of the experimentally determined polarisation with the calculated one the most appropriate model of the pyridinium cation reorientation has been chosen.

Molecular Physics, 101(10), 1469-1476 (2003)

DOI: 10.1080/0026897031000082167


68.

Domka L., Foltynowicz Z., Jurga S., Kozak M.

Influence of silane modification of kaolins on physico-mechanical and structural properties of filled PVC composites The paper presents the results of a study of the potential of modified kaolin as a filler for PVC. Kaolin from Maria III deposits in Poland was used. Aminosilanes and mercaptosilanes were used to modify the surface. Basic physicochemical parameters, such as the absorption capacity of the plasticiser, the heat of immersion in hydrophobic and hydrophilic solvents, and the morphology of particles of the modified filler were characterised. The modified kaolins clearly improved the physico-mechanical properties of PVC, in particular, they increased the elongation of PVC, when used at 10% and 15% w/w levels in the composite. Some studies of the microstructure of the filled composites were also performed using small angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) techniques.

Polymers and Polymer Composites, 11(5), 397-406 (2003)

DOI: 10.1177/096739110301100505   (Pobrane:  2021-01-10)


67.

Kiersnowski A., Kozak M., Jurga S., Pigłowski J.

Badania SAXS i DSC nanokompozytów poli(epsilon-kaprolakton)/organofilizowany montmorylonit Nanokompozyty otrzymano na drodze interkalacyjnej polimeryzacji kaprolaktonu w obecności 10% i 50% wag. syntetycznego montmorylonitu sodowego organofilizowanego bromkiem heksadecylotrimetyloamoniowym (HTAB). Badania strukturalne uzyskanych nanokompozytów przeprowadzone techniką małokątowego rozpraszania promieni X przeprowadzone w zakresie -50˚ ± 70˚ dowiodły, że odległość międzypłaszczyznowa d0001 oraz stopień uporządkowania układu rosną wraz ze wzrostem temperatury. Aby wyjaśnić naturę obserwowanych przemian, próbki przebadano techniką różnicowej mikrokalorymetrii skaningowej (DSC). W oparciu o wyniki eksperymentów SAXS i DSC stwierdzono, że skok wartości d001 obserwowany w zakresie 0-45 ˚C spowodowany jest procesem krystalizacji PCLw matrycy oraz w obrębie galerii krzemianu. Zmiany poniżej i powyżej tego zakresu są efektem rozszerzalności termicznej polimeru zawartego w przestrzeniach międzypłaszczyznowych montmorylonitu.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej, 52, 381-384 (2003)

   (Pobrane:  2020-10-25)


66.

Szutkowski K., Klinowski J., Jurga S.

NMR studies of restricted diffusion in lyotropic systems Tortuosity, 1/alpha, and surface-to-volume ratio, S/V, were determined in aqueous solutions of decylammonium, dodecylammonium and tetradecylammonium chlorides of various concentrations by measuring the apparent diffusion coefficient of water, D-app(Delta). This was found to be much smaller than in the bulk state. Such restricted diffusion is interpreted in terms of the Mitra model, where D(A) depends on diffusion time and is controlled primarily by S/V. The samples exhibit lamellar (L), hexagonal (H) and isotropic (1) liquid crystalline phases. We observed changes in S/V upon phase transition. In the lamellar and hexagonal phases, the system is ordered, resulting in relatively small S/V ratios, compared to the micellar-isotropic phase. We did not observe a dependence on the diffusion time, A, in the isotropic phase, because the duration of the experiment was not sufficiently short to observe the change from Dapp(A) to Den. We observed the effective diffusion coefficient of water, which directly probes the tortuosity of the system. The S/V ratios were obtained by fitting the Mitra model, using known values of the bulk water diffusion coefficients, and the assumption that D-app --> D-0 for Delta --> 0. S/V is correlated with the type of structure, increasing on transition to the isotropic phase and decreasing on transition to other phases. The change in tortuosity is small, but slightly larger for the isotropic phase.
(C) 2002 Elsevier Science (USA).

Solid State Nuclear Magnetic Resonance, 22(2-3), 394-408 (2002)

DOI: 10.1006/snmr.2002.0087   (Pobrane:  2020-10-21)


65.

Banaszak M., Wołoszczuk S., Pakuła T., Jurga S.

Computer simulation of structure and microphase separation in model A-B-A triblock copolymers A set of computer simulations for three symmetric A-B-A triblock copolymer microarchitectures at varying temperatures is reported. By using the cooperative motion algorithm we obtain energy, specific heat, end-to-end distance, and bridging fraction as a function of the reduced temperature. The order-disorder transition temperatures are determined, an outline of a symmetric A-B-A triblock copolymer phase diagram is presented, and the visualization of different microstructures is given. A bicontinuous microstructure is reported at 67% fraction of A component.

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 66(3), 031804 (2002)

DOI: 10.1103/PhysRevE.66.031804


64.

Mozgawa W., Fojud Z., Handke A., Jurga S.

MAS NMR and FTIR spectra of framework aluminosilicates In the work, the results of Al-27 MAS NMR studies carried out for structures of different framework aluminosilicates are presented. The spectra of natural clinoptilolite and its sodium and hydrogen forms were measured. The zeolite spectra were obtained before and after incorporation of heavy metal cations (Pb2+, Cd2+, Ni2+ and Cr3+) into the zeolite structure. After decomposition of the spectra into component peaks differences caused by ion exchange were observed. Additionally, NMR spectra of kalsilite (framework aluminosilicate, not belonging to zeolite group) and other zeolites (chabazite, heulandite and analcime) were measured. Al-27 MAS NMR spectra of all the samples studied were compared with the FTIR spectra measured in the middle infrared region. Based on the results obtained it has been proved that the interpretation of spectra obtained using these two different techniques can give some information concerning changes occurring in various framework aluminosilicate structures.
(C) 2002 Elsevier Science B.V. All rights reserved.

Journal of Molecular Structure, 614(1-3), 281-287 (2002)

DOI: 10.1016/S0022-2860(02)00262-4   (Pobrane:  2020-10-21)


63.

Nozirov F., Szcześniak E., Fojud Z., Dobrzyński P., Klinowski J., Jurga S.

1H and 13C NMR studies of molecular dynamics in the biocopolymer of glycolide and epsilon-caprolactone Copolymers of glycolide and F-caprolactone were studied using differential scanning calorimetry and solid-state NMR. The variation of the T-1 relaxation time with temperature reflects local disorder and can be quantified in terms of the distribution of correlation times predicted by the Davidson-Cole model. T-1 relaxation is dominated by trans gauche lisomerisation, with an activation energy of 34-35 kJ mol(-1).
(C) 2002 Elsevier Science (USA).

Solid State Nuclear Magnetic Resonance, 22(1), 19-28 (2002)

DOI: 10.1006/snmr.2002.0056   (Pobrane:  2020-10-21)


62.

Nozirov F., Fojud Z., Klinowski J., Jurga S.

High-resolution solid-state 13C NMR studies of poly[(R)-3-hydroxybutyric] acid Solid poly[(R)-3-hydroxybutyric] acid was examined by high-resolution C-13 MAS NMR, differential scanning calorimetry and infrared spectroscopy. The C-13 methyl group resonance consists of three components: the rigid amorphous phase, the crystalline phase and the mobile amorphous phase. Spectral deconvolution, using the Lorentz function, reveals the relative amounts as 62% crystalline and 38% amorphous at 333 K, and 42% crystalline, 40% pure amorphous and 18% beta-orthorhombic at 413 K. NMR indicates a large difference in molecular mobility between the crystalline and amorphous regions of the sample. Infrared spectroscopy shows that the stretching at 1725 cm(-1) (characteristic of the a-form) comes from the crystalline region, and the bands at 1744 cm(-1) (characteristic of the beta-form) and 1800 cm(-1) come from the amorphous region.
(C) 2002 Elsevier Science (USA).

Solid State Nuclear Magnetic Resonance, 21(3-4), 197-203 (2002)

DOI: 10.1006/snmr.2002.0060   (Pobrane:  2020-10-23)


61.

Kozak M., Jurga S.

A comparison between the crystal and solution structures of Escherichia Coli asparaginase II The small angle X-ray scattering (SAXS) pattern of the homotetrameric asparaginase II from Escherichia coli was measured in solution in conditions resembling those in which its crystal form was obtained and compared with that calculated from the crystallographic model. The radius of gyration measured by SAYS is about 5% larger and the maximum dimension in the distance distribution function about 12% larger than the corresponding value calculated from the crystal structure. A comparison of the experimental and calculated distance distribution functions suggests that the overall quaternary structure in the crystal and in solution are similar but that the homotetramer is less compact in solution than in the crystal.

Acta Biochimica Polonica, 49(2), 509-513 (2002)

DOI: 10.18388/abp.2002_3810
WWW: http://www.actabp.pl/pdf/2_2002/509.pdf   (Pobrane:  2021-01-10)


60.

Głowinkowski S., Makrocka-Rydzyk M., Wanke S., Jurga S.

Molecular dynamics in polyethylene and ethylene-1-butene copolymer investigated by NMR methods H-1 and C-13 NMR spectra and H-1 spin-lattice relaxation times T1 and T1ρ have been employed to study the structure and molecular dynamics in polyethylene and ethylene-1-butene copolymer in the temperature range from 100 to 370 K. Results are interpreted in terms of alpha, beta and gamma-relaxation, as well as methyl group rotation. The activation energies for all motions were established. The incorporation of 1-butene into ethylene chain leads to an increase of mobility in amorphous and crystalline phases as well as appearance the C-13 resonance characteristic to the monoclinic structure in addition to the orthorhombic observed in both polymers. The crystallinity degree derived from T-1rho in studied polymers is close to that determined using DSC method.
(C) 2002 Elsevier Science Ltd. All rights reserved.

European Polymer Journal, 38(5), 961-969 (2002)

DOI: 10.1016/S0014-3057(01)00272-5   (Pobrane:  2020-10-23)


59.

Garbarczyk M., Kuhn W., Klinowski J., Jurga S.

Characterization of aged nitrile rubber elastomers by NMR spectroscopy and microimaging H-1 spin-lattice and spin-spin NMR relaxation times change markedly during the aging of nitrile rubber elastomers. NMR microimaging reveals heterogeneous changes in the aged samples. Aging proceeds mainly via additional chain cross-linking, and scission of the polymer chains does not appear to contribute. T-1 imaging shows that there is no spatial distribution of spin-lattice relaxation times.
© 2002 Elsevier Science Ltd. All rights reserved.

Polymer, 43(11), 3169-3172 (2002)

DOI: 10.1016/S0032-3861(02)00142-8


58.

Głowinkowski S., Kozak M., Nowaczyk G., Domka L., Jurga S.

Facultatis Chemiae Universitatis Studiorum Mickiewiczianae Posnaniensis Annales II, , 73-78 (2002)


ISSN: 1644-6364    (Pobrane:  2021-01-13)


57.

Domka L., Kozak M., Jurga S.

Facultatis Chemiae Universitatis Studiorum Mickiewiczianae Posnaniensis Annales II, , 65-72 (2002)


ISSN: 1644-6364    (Pobrane:  2021-01-13)


56.

Wasyluk L., Peplińska B., Klinowski J., Jurga S.

NMR studies of the molecular dynamics of tert-butyl chloride confined in the mesoporous molecular sieve MCM-41 The molecular dynamics of tert-butyl chloride (TBC) confined in the molecular sieve MCM-41 were investigated by measuring NMR linewidths, lineshapes, and H-1 and H-2 spin lattice relaxation times. The temperatures of phase transitions of confined TBC are different from those in bulk. The behaviour of confined TBC can be explained assuming that the guest molecules form two kinds of molecular layers, one located at the pore surface and the other at the centre of the pore.

Physical Chemistry Chemical Physics, 4(11), 2392-2397 (2002)

DOI: 10.1039/b200634k


55.

Foltynowicz Z., Jakubiak P., Judek Ł., Kozak M., Kuśmia S., Fojud Z., Domka L., Jurga S.

Polietylen modyfikowany mleczanem wapnia W pracy przedstawiono metodę otrzymywania polietylenu modyfikowanego mleczanem wapnia oraz pochodną krzemoorganiczną mleczanu wapnia. Stosowano różne ilości napełniacza. Uzyskane tworzywa biorozpraszalne poddano badaniom mechanicznym.

Mat. V Konferencji Naukowo-Technicznej "Polimery i Kompozyty Konstrukcyjne", , 61-65 (2002)


54.

Suchański W., Minkin P., Jurga S.

Molecular dynamics in supercooled m-fluoroaniline Molecular dynamics of meta-fluoroaniline (mFA) - the system which makes a simple glass forming liquid - was examined by C-13 NMR and dielectric relaxation measurements. Spin-lattice relaxation times TI, nuclear Overhauser (NOE) factors of chemically non-equivalent carbons and dielectric retaxation in mFA were measured as a function of temperature. The analysis showed that the correlation function describing molecular dynamics in mFA could he well described in terms of an asymmetric distribution of correlation rimes predicted by the Davidson-Cole model. The overall correlation times of mFA. derived from the simultaneous fitting of our TI, NOE, and dielectric data (as well as of the dielectric data obtained by Roessler's group) to the Davidson-Cole model, follow the non-Arrhenius temperature type of the behaviour in accordance with the Vogel-Fulcher equation.
(C) 2001 Elsevier Science B.V. All rights reserved.

Journal of Molecular Structure, 559(1-3), 179-185 (2001)

DOI: 10.1016/S0022-2860(00)00695-5   (Pobrane:  2020-10-21)


53.

Foltynowicz Z., Wienskowski K., Kozak M., Domka L., Jurga S.

Commodity Science in Global Quality Perspectives. Products - Technology, Quality and Envir, , 353-358 (2001)


52.

Nozirov F., Kozak M., Domka L., Jurga S.

NMR relaxation studies of polyhydroxybutyric acid (PHB) biodegradation by Escherichia Coli In the paper the biodegradation process of polyhydroxybutyric acid (PHB) copolymer, induced by Escherichia coli bacteria is monitored using nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM).

Molecular Physics Reports, 33, 102-105 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


51.

Kuśmia S., Szcześniak E., Jurga S.

Magnetic resonance imaging of solid polymer composite In this paper the use of magic echo phase encoding (MEPSI) technique to obtain magnetic resonance image of the solid polymer composite is reported. The 2D version of MEPSI without slice selection has been adapted. The experiment shows that one can obtain an image of a solid sample whose transverse relaxation time is of the order of dozen of microseconds.

Molecular Physics Reports, 33, 184-187 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


50.

Wasyluk L., Peplińska B., Jurga S.

Translational diffusion in tert-butyl chloride confined to MCM-41 The translational diffusion of bulk and confined to pores of 38 Angstrom of MCM-41 tert-butyl chloride was investigated in the temperature range 293-160 K by PFGSTE experiment. The diffusivity of bulk TBC undergoes a discontinuous reduction at the melting point. The activation energy of the process was calculated to be 15.4 kJ/mol in the liquid phase and 40.6 kJ/mol in the plastic phase. Diffusivity of TBC confined to MCM-41 is described by strongly non Gaussian propagators and the echo attenuation for long diffusion times exhibit diffusion diffraction.

Molecular Physics Reports, 33, 111-113 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1502-1250   (Pobrane:  2021-01-07)


49.

Szutkowski K., Jurga S.

NMR study of restricted diffusion in lyotropic systems We present NMR diffusion measurements of n-alkyl ammonium salts-water systems (with n = 10, 12, 14) in their isotropic, lamellar and hexagonal liquid crystalline phases. Our experimental data are explained in terms of non-restricted and restricted diffusion of water molecules. Using the model of Mitra for restricted diffusion of molecules we were able to determine the Surface to Volume Ratios in lamellar phases, which were decreasing with increasing temperature.

Molecular Physics Reports, 33, 179-183 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1502-1250   (Pobrane:  2021-01-07)


48.

Fojud Z., Jurga S.

High resolution 13C NMR and DSC studies of interdigitated- noninterdygitated phase transition in a series of alkylammonium chloridies Relation between length of the n-alkylammonium chains and phase transitions in series of alkylammonium chlorides is studied by DSC and 13C CPMAS NMR experiment. The results show that the phase transitions revealed by DSC and NMR are related with a motional freedom of CH2 and CH3 in the chains.

Molecular Physics Reports, 33, 172-174 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


47.

Wachowicz M., Fojud Z., Jurga S.

Fast field cycling proton NMR relaxation in decylammonium chloride/water system We have investigated the dispersion of the proton spin-lattice relaxation times in decylammonium chloride/water systems, which exhibit different liquid crystalline phases of isotropic (micelles), lamellar (layers), hexagonal (layers rolled up into cylinders), and of nematic structures. The measurements were performed in the frequency range from 3·10^3 to 1.6·10^7 Hz and in the temperature range from 10°C to 85°C. The analysis of relaxation dispersion curves gave us information on local collective molecular dynamics of the alkylammonium chains.

Molecular Physics Reports, 33, 176-178 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


46.

Garbarczyk M., Kuhn W., Jurga S.

Characterization of aged elastomers by NMR spectroscopy and microimaging In the following study we present the results of the investigation of aged elastomers by the NMR spectroscopic and microimaging methods. The series of nitrile rubber samples was investigated both filled and unfilled before and after aging. The samples were aged in a well-defined manner in the air stream at elevated temperature for several days. The T-1 and T-2 measurements and microimaging were done using the spin-echo with relaxation filters. Parameter selective images were obtained. The results show that there is a strong dependence of the relaxation times on the aging process. It is also shown that there are heterogeneous changes across the aged sample.

Molecular Physics Reports, 33, 106-110 (2001)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


45.

Suchański W., Jurga S., Pakuła T., Paluch M., Zioło J.

Molecular dynamics in supercooled di-isobutyl phthalate close to the glass transition The dynamics of the alpha -relaxation in a glass-forming low-molecular-weight system, diisobutyl phthalate (DIBP), has been studied by means of dielectric, nuclear magnetic and mechanical spectroscopies. By using these techniques we have covered a wide timescale ranging from 10(-11) to 10(2) s. Vogel-Fulcher con elation time behaviour and the Davidson-Cole distribution function make possible a simultaneous fitting of T-1, the nuclear Overhauser enhancement (NOE) factor and dielectric data over the temperature range (Tg - 4 K) < T < (Tg + 155 K). These results together with the viscosity data have been analysed in terms of the Debye diffusion.

Journal of Physics - Condensed Matter, 12(46), 9551-9562 (2000)

DOI: 10.1088/0953-8984/12/46/303


44.

Suchański W., Jurga S.

Molecular Physics Reports, 29, 130-134 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


43.

Czapla Z., Fojud Z., Cieślik J., Jurga S.

New aproach to assessment of aging processes at the cellular level by NMR spectroscopy The paper presents results of the proton relaxation time T1 measurements by 1H NMR for oral epithelium samples taken from 320 subjects, men and women, in different age, from 19 to 95 year old. The times of nuclear magnetic relaxation T1 were found to be correlated with the age of the subjects.

Molecular Physics Reports, 29, 228-231 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


42.

Fojud Z., Jurga S.

A study of interdygitated-noninterdygitated phase transition on n-octadecylammonium chloride C18H37NH3Cl by 13C CPMAS NMR An interrelation between the interdigitated-noniterdigitated phase transition and molecular dynamics of the alkylammonium chains in C18H37NH3Cl is studied by means of 13C CPMAS experiment . The results of the measurements of 13C spectra as a function of temperature show that the observed phase transition is related with a motional freedom of the methylene groups.

Molecular Physics Reports, 29, 47-50 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


41.

Nozirov F., Fojud Z., Szcześniak E., Jurga S.

Molecular dynamics in poly[(R)-3-hydroxybutyric acid] biopolymer as studied by NMR Nuclear magnetic resonance line shapes and spin-lattice relaxation rimes T-1 of H-1 and H-2 nuclei of poly[(R)-3-hydroxybutyric acid] have been measured in the temperature range 100-413 K. The results provide information on the local dynamics of the compound. Activation parameters of the revealed motion are determined.

Applied Magnetic Resonance, 18(1), 37-45 (2000)

DOI: 10.1007/BF03162097


40.

Leszczyński R., Byczkowski B., Jurga S., Korszun S.

NMR microimaging studies of the union between stock and scion In this study we demonstrate the applicability of nuclear magnetic resonance (NMR) microimaging in examining the efficiency of grafting coniferous plants. Grafting is a method of propagating plants. It is used mainly in gardening. In some cases it is the only possible way to propagate certain varieties (e.g., apple varieties). The biology of grafting is nor well investigated yet. Therefore we have decided to rake advantage of the magnetic resonance imaging techniques in order to estimate which of the commonly used grafting methods gives the best quality unions. Results of our experiment indicate that the quality of union depends very much on the grafting method. NMR images give more information about the graft than microscopic images. We hope that our technique can select the best way to prepare plants for grafting and indicate average time of union process.

Applied Magnetic Resonance, 18(1), 147-153 (2000)

DOI: 10.1007/BF03162106


39.

Makrocka-Rydzyk M., Głowinkowski S., Jurga S., Meyer W.H.

Molecular dynamics in comb-like ionene as studied by NMR Proton and fluorine second moment and spin-lattice relaxation times T-1 and T-1p have been employed to study molecular dynamics in the comb-like 1-6,6-16-Me-BF4 ionene in the temperature range from 110 up to 300 K. The existence of motions of methyl groups, trans-gauche isomerization, and/or rotation of the main- and side-chain methylene groups, as well as isotropic reorientation of tetrafluoroborate ions were established. The observed relaxation behaviors are explained by motional models which assume Davidson-Cole asymmetrical distribution of correlation rimes. The best-fit motional parameters are given.

Applied Magnetic Resonance, 18(1), 63-70 (2000)

DOI: 10.1007/BF03162099


38.

Fojud Z., Szcześniak E., Jurga K., Jurga S.

Molecular dynamics of n-dodecylammonium chloride studied by nuclear magnetic resonance The relation between molecular dynamics and phase properties of the bilayered compound C12H25NH3Cl is studied by differential scanning calorimetry, proton second moment, and spin-lattice relaxation Limes. In the low-temperature Phase I of the compound methyl and ammonium groups execute a classical threefold reorientation, while the alkylammonium chains are rigid on the nuclear magnetic resonance time scale. In the intermediate-temperature phase delta a trans-gauche isomerization of the alkyl chains is observed. In the high-temperature phase alpha the reorientation of the whole chains about their long axes, which are parallel to the normal to the ionic layer is evidenced. In the meta-stable epsilon phase the dynamics involves classical rotation of methyl and ammonium groups and CH2 groups motion of the trans-gauche isomerization type.

Applied Magnetic Resonance, 19(3-4), 413-420 (2000)

DOI: 10.1007/BF03162384


37.

Fojud Z., Boeffel C., Szcześniak E., Jurga S.

2H and 13C CPMAS NMR study of chain dynamics in n-dodecylammonium chloride The H-2 NMR spectra of the selectively deuterated polycrystalline n-dodecylammonium chloride as well as C-13 CPMAS spectra of this compound are studied over a wide range of temperature. The results reveal a variety of phase transitions occurring in this model bilayer system and make it possible to relate them to the local molecular dynamics of the alkyl chains.
(C) 2000 Elsevier Science B.V. All rights reserved.

Journal of Molecular Structure, 555, 107-117 (2000)

DOI: 10.1016/S0022-2860(00)00592-5   (Pobrane:  2020-10-21)


36.

Kuśmia S., Szcześniak E., Jurga S.

Visualisation of fluid migration into porous poly(vinylalkohol) using MRI techniques Information on migration of liquids into porous media and on mobility of the absorbed fluids is of great relevance for the theory and for many branches of the materials science. In this paper we use magnetic resonance microimaging to visualise migration of water and chloroform into porous poly(vinylalkohol) (PVA). The images taken using gradient echo fast imaging (GEFI) and constant time imaging (CTI) methods show differences, which are assumed to reflect the restriction of mobility of water molecules due to formation of hydrogen bonds with hydrophilic PVA.

Molecular Physics Reports, 28, 106-108 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


35.

Peplińska B., Wasyluk L., Łaniecki M., Jurga S.

Dynamics in tert-butyl chloride confined to MCM-41 The molecular dynamic of tert-butyl chloride confined to pores of 24.4 Angstrom of MCM-41 is investigated by deuterium NMR spectroscopy. The temperatures of the all phase transitions are depressed by about 10 K in porous MCM-41 relative to the bulk transitions. The rotation of the (CD3)(3) about C-CI (C) axis is less restricted than CD3 rotation about C-C bond (C-3) axis. Variable temperature lineshape analysis yield the activation energy for C3 rotation of E-a = 5.2 kcal/mol in good agreement with E-a = 4.5 kcal/mol obtained from the temperature dependence of spin-lattice relaxation times.

Molecular Physics Report, 29, 50-54 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/


34.

Suchański W., Szcześniak E., Jurga S.

Nuclear magnetic relaxation study of carbon-13 in di-pentyl phthalate Spin-lattice relaxation times T-1 and nuclear Overhauser enhancement factors of chemically non-equivalent carbons in di-pentyl phthalate (DPP), a simple glass-forming liquid, are measured as functions of temperature. The analysis shows that the correlation function describing the overall molecular dynamics in DPP can be well described in terms of an asymmetric distribution of correlation times predicted by the Davidson-Cole model. The distribution parameters beta of the successive chain carbons are derived and analysed in terms of internal motions occurring in DPP.

Journal of Physics-Condensed Matter, 11(19), 3907-3914 (1999)

DOI: 10.1088/0953-8984/11/19/310


33.

Suchański W., Szcześniak E., Jurga S.

13C NMR relaxation in supercooled di-methyl phthalate Spin-lattice relaxation times (T-1) and nuclear Overhauser enhancement factors (NOE) for the individual ring carbons in di-methyl phthalate (DMF) were measured over a wide range of temperatures. The results show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be well described by a Davidson-Cole distribution. The viscosity dependence of the reorientational correlation time tau derived is analysed to investigate the adequacy of the modified Debye equation to description of the microscopic behaviour of supercooled systems.

Journal of Physics-Condensed Matter, 10(28), 6243-6249 (1998)

DOI: 10.1088/0953-8984/10/28/006


32.

Szcześniak E., Głowinkowski S., Suchański W., Jurga S.

Dynamics of glass-forming di-n-butyl phthalate as studied by NMR Spin-lattice relaxation times T-1 and nuclear Overhauser effect (NOE) enhancement factors for the individual ring carbons in di-n-butyl phthalate (DBF) show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be described by a Davidson-Cole distribution. Measurements of proton spin-lattice relaxation times T-1 and T-1p, as well as H-1 NMR spectra at temperatures below the glass transition temperature, Tg, reveal that the same distribution holds also for description of local dynamics in glassy DBF. The activation parameters of the motions detected are derived.
(C) 1997 Elsevier Science B.V.

Solid State Nuclear Magnetic Resonance, 8(2), 73-79 (1997)

DOI: 10.1016/S0926-2040(96)01292-1   (Pobrane:  2020-10-21)


31.

Głowinkowski S., Jurga S., Suchański W., Szcześniak E.

Local and global dynamics in the glass-forming di-isobutyl phthalate as studied by 1H NMR Spin-lattice relaxation times T-1 and T1ρ as well as H-1 NMR spectra have been employed to study the dynamics of the glass-forming di-isobutyl phthalate in the temperature range extending from 100 K, through the glass transition temperature Tg, up to 340 K. Below Tg NMR relaxation is governed by local dynamics and may be attributed to rotation of methyl groups at low temperatures and to motion of isobutyl groups in the intermediate temperature interval. Above Tg the main relaxation mechanism is provided by overall molecular motion. The observed relaxation behavior is explained by motional models assuming asymmetrical distributions of correlation times. The motional parameters obtained from Davidson-Cole distribution, which yields the best fit of the data at all temperatures are given.
(C) 1997 Elsevier Science B.V.

Solid State Nuclear Magnetic Resonance, 7(4), 313-317 (1997)

DOI: 10.1016/S0926-2040(96)01266-0   (Pobrane:  2020-10-23)


30.

Głowinkowski S., Jurga S., Suchański W., Szcześniak E.

Dynamics of t-butyl groups in a series of related molecular solids The dynamics of the lowest temperature phase of a series of closely related t-butyl compounds (CH3)CXH, whre X=O, S, Se, has been studied using 1H NMR. The obtained data allowed the separation of the dynamics arising from methyl group and from t-butyl group. The activation parameters of the motions are given. It is shown that the t-butyl group is more mobile than constituent methyl groups and that coupling between these two motions is associated with the observed order-disorder phase transition.

Molecular Physics Reports, 14, 83-87 (1996)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)


29.

Makrocka-Rydzyk M., Głowinkowski S., Jurga S., Meyer W.H.

Molecular dynamics in stiff ionene below glass-transition Temperature dependences of proton and fluorine second moments and spin-lattice relaxation time T-1 below glass transition were measured in glassy ''I-Do,Pip-Me-BF4'' ionene. The existence of motions of methyl groups and segments linking the cationic centers, namely piperidinium rings and trimethylene groups, for the polymeric part of ionene were established. Isotropic rotation of the counter-ion was evidenced and its limited diffusion suggested. To interpret the proton and fluorine relaxation data, a Davidson-Cole distribution of correlation times was assumed.

Solid State Nuclear Magnetic Resonance, 4(6), 353-360 (1995)

DOI: 10.1016/0926-2040(95)00013-G


28.

Jurga K., Reynhardt E.C., Jurga S.

Measurement and interpretation of far off-resonance T1R in solids Apparatus and procedure for measuring nuclear magnetic resonance spin-lattice relaxation times in the rotating frame in the presence of an off-resonance radiofrequency field in solids are described. The procedure for the direct measurement of correlation times is also described. Experiments were performed at a Larmor frequency of 75 MHz.

Measurement Science and Technology, 5(1), 27-31 (1994)

DOI: 10.1088/0957-0233/5/1/005


27.

Jurga K., Reynhardt E.C., Jurga S.

A simple high-performance broadband NMR transmit-receive system A broadband transmit-receive system with excellent isolation, operating in the frequency range 15 to 100 MHz, is described. In transmiting mode the transmitter-probe attenuation for the strong RF pulse does not exceed 1.2 dB, while the transmitter-receiver isolation is better than 42 dB. In receiving mode the transmitter-receiver isolation for the weak nuclear signal is better than 40 dB and the probe-receiver attenuation is equal to or less than 2.6 dB. The system is simple and relatively cheap.

Journal of Magnetic Resonance, Series A, 101(1), 74-77 (1993)

DOI: 10.1006/jmra.1993.1010


26.

Jurga K., Reynhardt E.C., Jurga S.

A proton NMR study of n-decylammonium chain dynamics in the perovskite-type layered compound (C10H21NH3)2CDCL4 A detailed proton second moment and spin-lattice relaxation time investigation of the bilayered compound (C10H21NH3)2CdCl4 is reported. In the low temperature phase the methyl group executes a classical threefold reorientation, while the NH3 group is involved in a similar reorientation in an asymmetric potential well. Evidence for defect chain motions in this phase has been found, and information regarding the potential wells associated with these motions has been extracted from the data. In the high temperature phase, slow chain defect motions and fast fourfold reorientations of chains about their long axes, parallel to the normal to the bilayer, have been observed.

Zeitschrift fur Naturforschung Section A-A Journal of Physical Sciences, 48(4), 563-569 (1993)

DOI: 10.1515/zna-1993-0405   (Pobrane:  2021-01-10)


25.

Fenrych J., Reynhardt E.C., Jurga S., Jurga K.

Molecular motions and phase changes in the perovskite-type compound (C10H21NH3)2ZnCl4 A virgin sample of polycrystalline (C10H21NH3)2ZnCl4 shows two phase transitions, at 284 K and 363 K. In the low-temperature phase threefold reorientations of methyl and NH3 groups dominate the nuclear magnetic resonance relaxation results. The motion of the NH3 groups can be described as a three-fold jump among three potential minima of which one is shallower than the other two. In the intermediate temperature phase a defect motion of chain ends has been identified. In the high-temperature phase the spacing between adjacent layers of ZnCl4 tetrahedra is increased by ∼ 16% due to the non-intercalation of the chains. In this phase the chains experience a high degree of mobility, which is partly due to the diffusion of chain defects along the chain. On cooling the sample from the high-temperature phase, it transforms to the intermediate phase, but the transition to the low-temperature phase is absent.

Molecular Physics, 78(5), 1117-1128 (1993)

DOI: 10.1080/00268979300100721


24.

Fenrych J., Reynhardt E.C., Jurga S., Jurga K.

Molecular motions and phase changes in the perovskite-type compound (C13H27NH3)2ZnCl4 In the low-temperature (T < 304K) phase both CH3 and NH3 groups execute threefold reorientations, the former in a symmetric potential well and the latter in an asymmetric potential well. The relaxation results in the rotating frame reveal a defect motion in this phase. Additional defect motions, superimposed on fourfold reorientations of chains, are present in phase II (317 K < T < 369K). In phase I (T > 369 K), melting of chains occurs. Although hydrogen bonding is stronger in (C13H27NH3)2ZnCl4 than in (C10H21NH3)2ZnCl4, fast fourfold motions of chains are present at lower temperatures in the former compound. Melting of chains occurs at approximately the same temperature in these compounds.

Molecular Physics, 79(3), 559-569 (1993)

DOI: 10.1080/00268979300101451


23.

Szcześniak E., Głowinkowski S., Jurga S.

Proccedings of 15th Conference on Radio and Microwave Spectroscopy, Poznań (Poland), , 89 (1993)


22.

Głowinkowski S., Jurga S., Szcześniak E.

Interrelation between molecular motions and structure in solid trimethylamine-boron-trichloride as studied by NMR The temperature dependences of proton second-moment and spin-lattice relaxation times (T1 and T1Q) have been measured in solid (CH3)3NBCl3. The nature of reorientation processes occurring in the complex has been established and the activation parameters determined. The motions are discussed in relation to the molecular structure of the complex.

Zeitschrift fur Naturforschung Section A-A Journal of Physical Sciences, 47(11), 1157-1160 (1992)

DOI: 10.1515/zna-1992-1113   (Pobrane:  2021-01-10)


21.

Jurga K., Reynhardt E.C., Jurga S.

NMR transmit-receive system with short recovery time and effective isolation A transmit-receive system with a short recovery time and excellent isolation has been developed. The system operates in conjunction with an ENI Model 3200L broadband amplifier and a spin-lock NMR pulse spectrometer. The system has been tested in the frequency range 5.5 to 52 MHz and seems not to generate any background noise.

Journal of Magnetic Resonance (1969), 96(2), 302–306 (1992)

DOI: 10.1016/0022-2364(92)90083-J


20.

Reynhardt E.C., Jurga S., Jurga K.

The structure and molecular dynamics of solid n-decylammonium chloride The results of a detailed DSC, X-ray powder diffraction and NMR investigation of n-decylammonium chloride (C10H21NH3Cl) are reported. If a sample in the interdigitated I phase is heated, it transforms to the non-interdigitated δ phase at ∼328K and then to the β and α phase at ∼334K. On cooling the transitions to the β and δ phases occur at ∼322K and 319K, respectively, but instead of returning to the I phase, the sample transforms to the ϵ phase at ∼297K. The ϵ phase is metastable, but becomes stable below ∼210K. If the sample is heated from a temperature below 210K, it shows a transition to the ϵ′ phase at ∼288K and then to the δ, β and α phases. A sample heated from the metastable ϵ phase does not show the transition to the ϵ′ phase, but exhibits an exothermic transition at ∼274K. In the ϵ phase the intensity of diffraction peaks are relatively weak due to a disordered lattice. If the temperature is lowered from the δ → ϵ transition temperature the relatively large expansion coefficient of the a cell dimension above 210K is attributed to the gradual freezing of chain reorientations. Below 210K the expansion coefficients are similar to those of the I phase. If the sample is now heated to temperatures above 210K, the temperature dependence of the length of the c axis becomes anomalous. In the I phase the methyl groups excute classical threefold reorientations, while NH3 groups jump among three potential wells with unequal depths. Chain reorientations only start to influence the results in the vicinity of the transition to the high temperature phases. On cooling from the high temperature phases the chains execute fourfold reorientations about their long axes, which are reduced to twofold reorientations at lower temperatures. Below 210K all chain motions are frozen. If the sample is heated above 210K the chains are limited to twofold reorientations which are frozen within a few hours. The results suggest that the potential barriers to chain reorientations are a function of time.

Molecular Physics, 77(2), 257-278 (1992)

DOI: 10.1080/00268979200102431


19.

Reynhardt E.C., Jurga S., Jurga K.

Molecular motion and disorder in trimethyloxosulphonium fluoroborate Proton and fluorine second moments and spin-lattice relaxation times have been measured in a polycrystalline sample of trimethyloxosulphonium fluoroborate. Methyl groups execute threefold reorientation with an activation energy of 9.2+or-0.5 kJ mol-1. The activation energy for the threefold reorientation of the anion is 33+or-3 kJ in mol-1. The disorder of the BF4- ion is dynamic. The ion jumps between two equilibrium orientations which have six fluorine and two boron equilibrium positions. The activation energy for this rotational-translational motion is 8.8+or-0.5 kJ mol-1. Further reorientations of the ion about its symmetry axes result in an isotropically reorienting ion. The activation energy for this motion is 17.6+or-0.8 kJ mol-1.

Journal of Physics: Condensed Matter, 4(24), 5433-5442 (1992)

DOI: 10.1088/0953-8984/4/24/013


18.

Reynhardt E.C., Jurga S., Jurga K.

The coexistence of phases in solid tetramethylammonium hexafluorophosphate A study of polycrystalline tetramethylammonium hexafluorophosphate, employing techniques in differential scanning colorimetry, X-ray powder diffraction and nuclear magnetic resonance, is reported. The results are explained in terms of a two-phase model in which a phase containing imperfections coexists with a phase without imperfections. The similarity between the transition between these two phases and a martensitic transition is emphasised.

Chemical Physics Letters, 194(4-6), 410-414 (1992)

DOI: 10.1016/0009-2614(92)86074-R


17.

Jurga S., Macho V., Hüser B, Spiess H.W.

Chain dynamics of bilayer n-decylammonium chloride studied by deuteron NMR spectroscopy N-decylammonium chloride is a polymorphic solid which exhibits a variety of layered phases. The molecular dynamics and phase transitions in these phases have been studied using2H NMR of selectively deuterated n-decylammonium in the chain positions 1 and 6 and in the ammonium group. Measurements were performed over the temperature range of the interdigitated phase I, the non-interdigitated monoclinic phase δ, the tetragonal phase α, and the monotropic phase ε, obtained upon cooling the sample from the α-phase. In phase I, below 321 K, the hydrocarbon chain is rigid except for ND3 rotation about its own symmetry axis. In phase δ, between 321 K and 325 K, a fast motion of the hydrocarbon chains is assigned to an exchange between two pairwise nonequivalent positions. The chains are slightly tilted in this phase. In phase α above 325 K the chains rotate freely around their long axes experiencing additional transgauche conformational dynamics. In the non-interdigitated phase ε the spectra can be interpreted by assuming a reorientation between two variously occupied potential wells about the axis determined by the C-N bond, which is believed to be parallel to the normal bilayer axis.

Zeitschrift fur Physik B Condensed Matter, 84(1), 43-49 (1991)

DOI: 10.1007/BF01453757


16.

Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Wiadomości Chemiczne, 42(1), 25 (1988)


15.

Jurga S., Seliger J., Blinc R., Spiess H.W.

14N and 35Cl double resonance study of the low-temperature phase transition in CH3NH3ClO4 A 14N and 35Cl double resonance study of CH3NH3ClO4 shows that, contrary to the high-temperature phase transition being due to a change of molecular motion of the cations, the low-temperature phase transition is triggered by a change of molecular dynamics of the anions. This shows the importance of measuring the chlorine quadrupole frequency of perchlorate ions in the solid state which has not been detected so far.

Physics Letters A, 116(6), 295-298 (1986)

DOI: 10.1016/0375-9601(86)90598-0


14.

Jurga S., Harbison G.S., Blumich B., Spiess H.W., Fujara F.

Static and MAS 35CI NMR and molecular motions of ClO ions in the various phases of multimethylammonium perchlorates Static and MAS*) 35CI NMR data of CIO−4 ions in the low-, intermediate- and high-temperature phases of trimethylammonium, dimethylammonium and monomethylammonium perchlorates are reported. The observed solid-solid phase transitions are interrelated with the motional state of the perchlorate ions. In the low-temperature phase III of trimethylammonium perchlorate there is an anisotropic motion of the ClO−4 ions with a constant quadrupole frequency of 185 kHz and an increasing value of the asymmetry parameter when approaching phase transition III-II. The activation energy for this motion is found to be 44.3 kj/mol. At the transition III-II the ClO−4 ions gain orientational degrees of freedom manifested by the change of the quadrupole frequency to 159 kHz. In phase II the perchlorate ions undergo an axial motion overcoming the energy barrier of 40.7 kj/mol. In the low-temperature phase III of dimethylammonium perchlorate there are rigid ClO−4 ions. At the phase transition III-II the ClO−4 ions gain considerable motional freedom indicated by lowering the quadrupole frequency to 119 kHz, due to an anisotropic motion. In the high-temperature phase I the anions undergo isotropic motion with the activation energy of 11.9 kj/mol. The low-temperature phase III of monomethylammonium perchlorate is characterized by rigid ClO−4 ions. At the transition III-II the ClO−4 ions gain a considerable motional freedom and undergo an axial motion in phase II. In phase I motion of the anions is isotropic. The motional behaviour of the anions along with NMR data for the cations suggests that the low-temperature ordering of the ions in phase HI is due to hydrogen-bonds N[BOND]H … O[BOND]Cl, the partial breaking of which, accompanied by the phase transition III-II, leads to an axial motion of the ions in phase II. A complete breaking of all hydrogen-bonds in phase I allows the ions to reorient isotropically. The quadrupole coupling constant of rigid ClO−4 ions amounts to about 1 MHz.

Berichte der Bunsengesellschaft fur Physikalische Chemie, 90(12), 1153-1159 (1986)

DOI: 10.1002/bbpc.19860901207


13.

Jurga S., Spiess H.W.

Zeitschrift fur Naturforschung Section A-A Journal of Physical Sciences, 40(6), 602-610 (1985)

DOI: 10.1515/zna-1985-0611   (Pobrane:  2021-01-10)


12.

Jurga S., Spiess H.W.

Phase transitions and molecular motion in dimethylammonium perchlorate as revealed by DSC, proton and deuteron NMR Differential scanning calorimetry, the temperature dependence of proton and deuteron lineshapes and spin-lattice relaxation times are reported for (CH3)2NH2ClO4 and its selectively deuterated analogue (CH3)2ND2ClO4. Our caloric data revealed the existence of three different phase modifications in dimethylammonium perchlorate, analogous to mono- and trimethylammonium perchlorate. An analysis of the NMR data enabled identification of the molecular motions occurring in the respective phases and to determine their activation parameters. In the low-temperature phase III stable below 309 K there are two inequivalent dimethylammonium cations which manifest themselves by different reorientation frequencies of methyl groups about their threefold symmetry axes C3 and by reorientation of one of the two inequivalent cations about its pseudo threefold symmetry axis C'3 lying along one of the two N[BOND]D bonds. In the low-temperature range of this phase the deuteron quadrupole coupling constant indicates N[BOND]H…O hydrogen bonds between the dimethylammonium and the perchlorate ions. The intermediate phase II has not been reported so far. It is stable in the temperature range 309 - 311 K, but can easily be undercooled below 290 K. In this phase one of the two cations undergoes reorientation about its diad C2 axis, whereas the other still reorients about the C'3 axis. The analysis of the large entropy change of 25.5 J/mol · K associated with the III−II transition indicates that the ClO4 ions in phase II have considerable motional freedom, presumably due to breaking of N [BOND] H… O hydrogen bonds. In phase I the dimethylammonium cations undergo quasiisotropic reorientation about their centers of gravity and translational diffusion between different sites of the tetragonal unit cell.

Berichte der Bunsengesellschaft fur Physikalische Chemie, 89(7), 763-771 (1985)

DOI: 10.1002/bbpc.19850890709


11.

Jurga S.

Molecular motions and polymorphic phase transitions in (CH3)4NClO4, and (CH3), NHCl04 as studied by NMR The temperature dependences of the proton spin-lattice relaxation times T1, T1p, and T1D as well as the second moment M2, are reported for the phase II of tetramethylammonium perchlorate (CH3)4, NClO4, and for the phases III, II, and I of trimethylammonium perchlorate (CH3), NHCl04. An analysis of these data allows to reveal various molecular motions in the appropriate phase modifications and to determine their activation energies and correlation times.

Physica Status Solidi A, 81(1), 77-85 (1984)

DOI: 10.1002/pssa.2210810107


10.

Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Postępy w zastosowaniu technik rezonansowych w chemii, red. Lucjan Sobczyk, PWN Warszawa, , 42-54 (1984)


ISBN: 83-01-04687-2


9.

Jurga S., Depireux J.

Proton and fluorine nuclear magnetic resonance studies of molecular motion in dimethyl sulfoxide-boron trifluoride complex Proton and fluorine second moments and spin-lattice relaxation times have been studied over a wide temperature range in solid dimethyl sulfoxide-boron trifluoride (CH3)2SO · BF3 and in its deuterated analog (CD3)2SO · BF3. The results indicate that the two methyl groups are dynamically inequivalent within the molecule and reorient at and above 77 K about their threefold symmetry axes (C3) with different frequencies and with activation energies of 6.69 and 10.45 kJ/mol. The BF3 group is rigid at 77 K, while above 135 K it reorients about its C3 symmetry axis with an activation energy of 15.93 kJ/mol. The low-temperature fluorine relaxation is controlled by the reorientation of the methyl groups which is faster than that of BF3. This allows one to deduce for the fluorine-proton second moment a value indicating that the BF3 group is closer to one of the two methyl groups in the proton-containing compound.

Journal of Magnetic Resonance (1969), 55(1), 12-23 (1983)

DOI: 10.1016/0022-2364(83)90273-1


8.

Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Fizyka w Szkole, 6(167), 330 (1983)


ISSN: 0426-3383   (Pobrane:  2021-01-11)


7.

Jurga S., Jurga K., Pająk Z.

Composite motion of molecular groups in solid triethylphosphine oxide as studied by NMR Second moments and spin-lattice relaxation times in the laboratory and rotating frames were determined for solid triethylphosphine oxide (C2H5)3PO over the temperature range 77 to 320 K. Theoretical expressions were derived for the T1 and T1π relaxation behavior of the ethyl group in (C2H5)3PO undergoing the composite motion of reorientation about C-P axis, P-O axis, and isotropic tumbling of the (C2H5)3PO molecule, under the assumption of rapid spin exchange between the CH2 and CH3 groups and internal motion of the CH3 group about its threefold axis within the ethyl group. These expressions were applied to analyze the experimental T1 and T1π data, and the results obtained along with the second moment measurement allowed us to assess the following motions: (i) methyl group reorientation about its C3 axis, (ii) ethyl group reorientation about the C-P axis, and (iii) molecular reorientation about the P-O axis, with activation energies of about 8.3, about 22.9, and 40.1 kJ/mol, respectively.

Journal of Magnetic Resonance (1969), 50(2), 175-187 (1982)

DOI: 10.1016/0022-2364(82)90047-6


6.

Jurga S., Jurga K., Pająk Z.

NMR study of molecular motion in solid trimethyloxosulphonium halides NMR second moments M2 and spin-lattice relaxation times in the laboratory and rotating frame T1 and T1ρ for trimethyloxosulphonium fluoride, chloride, bromide and iodide are reported over a wide temperature range. The variations of M2, T1 and T1ρ for each of these salts are interpreted in terms of methyl group reorientation about its C3 axis and reorientation of the TMOS ion about its C3' symmetry axis; the respective activation parameters are estimated. It is found that trimethyloxosulphonium chloride contains two types of methyl groups statistically weighted in the ratio 2:1, reorienting with different frequencies about their C3 axes.

Journal of Physics C: Solid State Physics, 14(30), 4433-4446 (1981)

DOI: 10.1088/0022-3719/14/30/010   (Pobrane:  2020-10-23)


5.

Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Postępy Fizyki Molekularnej, 31, 5-22 (1980)

   (Pobrane:  2021-01-11)


4.

Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Wydawnictwo Naukowe Uniwersytetu im. Adama Mickiewicza, 41, (1980)

WWW: http://www.press.amu.edu.pl/
ISSN: 0554-825 X


3.

Jurga S., Depireux J., Pająk Z.

Proccedings of the 18th Ampere Congress on Magnetic Resonance and Related Phenomena, Nottingham (United Kingdom), 11, 403-404 (1975)


2.

Pająk Z., Jurga K., Jurga S.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
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oraz w wydawnictwach popularno - naukowych.

Impulsowy spektrometr Jądrowego Rezonansu Paramagnetycznego do badania ciał stałych Construction an operation of a 25 MHz single-coil pulse spectrometer characterized by a 4.0 µs recovery and 1.5 µs pulse length for protons is described.

Postępy Fizyki, 25(2), 193-197 (1974)

WWW: http://www.ptf.net.pl/pl/aktualnosci/informacje-biezace/archiwum-postepow-fizyki/
ISSN: 0032-5430   (Pobrane:  2021-01-11)


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Pająk Z., Jurga K., Jur