	49.	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)

	48.	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)

	47.	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)

	46.	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)

	45.	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)

	44.	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)

	43.	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)

	42.	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)

	41.	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)

	40.	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)

	39.	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)

	38.	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)

	37.	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

	36.	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

	35.	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

	34.	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

	33.	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)

	32.	Mazierski P., Malankowska A., Kobylański M., Diak M., Kozak, M., Winiarski M.J., Klimczuk T., Lisowski W., Nowaczyk G., Zaleska-Medyńska A.
		Functionalized multimodal ZnO@Gd2O3 nanosystems to use as perspective contrast agent for MRI The development of a photocatalyst with remarkable activity to degrade pollutants in aqueous and gas phase requires visible light-responsive stable materials, easily organized in the form of a thin layer (to exclude the highly expensive separation step). In this work, we present a one-step strategy for synthesizing material in the form of a self-organized TiO2/Ag2O nanotube (NT) array interlaced with silver nanoparticles (as in a cake with raisins) that exhibited photoactivity significantly enhanced compared to that of pristine TiO2 NTs under both ultraviolet (UV) and visible (vis) irradiation. An NT array composed of a mixture of Ti-O2 and Ag2O and spiked with Ag nanoparticles was formed via the anodization of a Ti-Ag alloy in a one-step reaction. Silver NPs have been formed during the in situ generation of Ag ions and were (i) embedded in the NT walls, (ii) stuck on the external NT walls, and (iii) placed inside the NTs. The enhancement of photocatalytic efficiency can be ascribed to the existence of an optimal content of Ag2O and Ag NPs, which are responsible for decreasing the number of recombination centers. In contrast to UV-vis light, performance improvement under vis irradiation occurs with increasing Ag2O and Ag0 contents in the TiO2/Ag2O/Ag NTs as a result of the utilization of larger amounts of incident photons. The optimized samples reached phenol degradation rates of 0.50 and 2.89 mu mol dm(-3) min(-1) under visible and UV light, respectively, which means degradation activities 3.8- and 2-fold greater than that of the reference sample, respectively, remained after four photodegradation cycles under UV light.
		ACS Catalysis, 7(4), 2753-2764 (2017)
		DOI: 10.1021/acscatal.7b00056

	31.	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

	30.	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

	29.	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

	28.	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)

	27.	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

	26.	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)

	25.	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)

	24.	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)

	23.	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

	22.	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)

	21.	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

	20.	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

	19.	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

	18.	Hałupka-Bryl M., Bednarowicz M., Dobosz B., Krzyminiewski R., Zalewski T., Wereszczyńska B., Nowaczyk G., Jarek M., Nagasaki Y.
		Doxorubicin loaded PEG-b-poly(4-vinylbenzylphosphonate) coated magnetic iron oxide nanoparticles for targeted drug delivery Due to their unique physical properties, superparamagnetic iron oxide nanoparticles are increasingly used in medical applications. They are very useful carriers for delivering antitumor drugs in targeted cancer treatment. Magnetic nanoparticles with chemiotherapeutic were synthesized by coprecipitation method followed by coaling with biocompatible polymer. The aim of this work is to characterize physical and magnetic properties of synthesized nanoparicles. Characterization was carried out using EPR, HRTEM, X-ray diffraction, SQUID and NMR methods. The present findings show that synthesized nanosystem is promising tool for potential magnetic drug delivery. (C) 2015 Elsevier B.V. All rights reserved
		Journal of Magnetism and Magnetic Materials, 384, 320-327 (2015)
		DOI: 10.1016/j.jmmm.2015.02.078 (Pobrane: 2020-10-23)

	17.	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

	16.	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)

	15.	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)

	14.	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)

	13.	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)

	12.	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

	11.	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)

	10.	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)

	9.	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

	8.	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

	7.	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)

	6.	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

	5.	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

	4.	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

	3.	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)

	2.	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)

	1.	Głowinkowski S., Kozak M., Nowaczyk G., Domka L., Jurga S.
		Badania układów polimer-napełniacz metodami NMR i reologicznymi
		Facultatis Chemiae Universitatis Studiorum Mickiewiczianae Posnaniensis Annales II, , 73-78 (2002)
		ISSN: 1644-6364 (Pobrane: 2021-01-13)