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2021 |
Avdović, E H; Dimić, D S; Fronc, M; Kožišek, J; Klein, E; Milanović, Ž B; Kesić, A; Marković, Z S Journal of Molecular Structure, 1231 , 2021. @article{Avdović2021, title = {Structural and theoretical analysis, molecular docking/dynamics investigation of 3-(1-m-chloridoethylidene)-chromane-2,4‑dione: The role of chlorine atom}, author = {E H Avdović and D S Dimić and M Fronc and J Kožišek and E Klein and Ž B Milanović and A Kesić and Z S Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100428361&doi=10.1016%2fj.molstruc.2021.129962&partnerID=40&md5=a831cb6950697fc26c830f86199c0162}, doi = {10.1016/j.molstruc.2021.129962}, year = {2021}, date = {2021-01-01}, journal = {Journal of Molecular Structure}, volume = {1231}, abstract = {The coumarin derivative, 3-(1-m-chloridoethylidene)-chroman-2,4‑dione, was previously synthesized by a conventional method. Detailed structural characterization of the obtained compound was performed by using X-ray crystallography and vibrational analysis. Experimental data were confirmed by the optimization of a structure employing three common functionals (B3LYP-D3BJ, M06–2X, and APF-D) in combination with a 6–311+G(d,p) basis set. Low values of the average absolute error and the high values of the correlation coefficient for bond lengths and angles, proved that B3LYP-D3BJ could be used for the structural and spectral analysis. The stability of the investigated compound was determined by Fukui functions, NBO, and QTAIM analyses along with various reactivity parameters. The special emphasis in the discussion was put on the role of a chlorine atom for the overall stability and reactivity by comparison with 3-(1-(phenylamino)ethylidene)-chromane-2,4‑dione. In silico simulations with Adenosine A2a receptors (ADORA2A), were performed using molecular docking and dynamics methods for both coumarin derivatives. The thermodynamic parameters and specific interactions proved the importance of chlorine atom for possible biological activity. © 2021}, keywords = {}, pubstate = {published}, tppubtype = {article} } The coumarin derivative, 3-(1-m-chloridoethylidene)-chroman-2,4‑dione, was previously synthesized by a conventional method. Detailed structural characterization of the obtained compound was performed by using X-ray crystallography and vibrational analysis. Experimental data were confirmed by the optimization of a structure employing three common functionals (B3LYP-D3BJ, M06–2X, and APF-D) in combination with a 6–311+G(d,p) basis set. Low values of the average absolute error and the high values of the correlation coefficient for bond lengths and angles, proved that B3LYP-D3BJ could be used for the structural and spectral analysis. The stability of the investigated compound was determined by Fukui functions, NBO, and QTAIM analyses along with various reactivity parameters. The special emphasis in the discussion was put on the role of a chlorine atom for the overall stability and reactivity by comparison with 3-(1-(phenylamino)ethylidene)-chromane-2,4‑dione. In silico simulations with Adenosine A2a receptors (ADORA2A), were performed using molecular docking and dynamics methods for both coumarin derivatives. The thermodynamic parameters and specific interactions proved the importance of chlorine atom for possible biological activity. © 2021 |
Ignjatović, S; Blawert, C; Serdechnova, M; Karpushenkov, S; Damjanović, M; Karlova, P; Wieland, D C F; Starykevich, M; Stojanović, S; Damjanović-Vasilić, L; Zheludkevich, M L Formation of multi-functional TiO2 surfaces on AA2024 alloy using plasma electrolytic oxidation Journal Article Applied Surface Science, 544 , 2021. @article{Ignjatović2021, title = {Formation of multi-functional TiO2 surfaces on AA2024 alloy using plasma electrolytic oxidation}, author = {S Ignjatović and C Blawert and M Serdechnova and S Karpushenkov and M Damjanović and P Karlova and D C F Wieland and M Starykevich and S Stojanović and L Damjanović-Vasilić and M L Zheludkevich}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098940165&doi=10.1016%2fj.apsusc.2020.148875&partnerID=40&md5=794c6ed0b6b4c7097aa90f21902eab5d}, doi = {10.1016/j.apsusc.2020.148875}, year = {2021}, date = {2021-01-01}, journal = {Applied Surface Science}, volume = {544}, abstract = {Plasma electrolytic oxidation (PEO) was applied to functionalise the surface of AA2024 alloy. A potassium titanium-oxide oxalate dihydrate based aqueous electrolyte was used, which allowed the direct formation of a TiO2 surface layer on the aluminium alloy substrate. The effect of PEO treatment time and the additional presence of anatase particles in the electrolyte solution on the surface layer and its properties (corrosion, wear and photocatalytic activity) were investigated. It was found that the coating thickness and surface morphology are strongly dependent on the PEO processing time. However, the phase composition is not much affected by the treatment time and the main coating phase is rutile with a smaller amount of anatase. Adding additional anatase in the form of particles increases the amount of anatase in the coatings. The additional particle addition has only minor effect on the corrosion resistance, but reduces the wear resistance remarkably. Interestingly, the addition of anatase particles and the PEO treatment time are not effective in increasing the photocatalytic activities of the samples. © 2020 The Author(s)}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plasma electrolytic oxidation (PEO) was applied to functionalise the surface of AA2024 alloy. A potassium titanium-oxide oxalate dihydrate based aqueous electrolyte was used, which allowed the direct formation of a TiO2 surface layer on the aluminium alloy substrate. The effect of PEO treatment time and the additional presence of anatase particles in the electrolyte solution on the surface layer and its properties (corrosion, wear and photocatalytic activity) were investigated. It was found that the coating thickness and surface morphology are strongly dependent on the PEO processing time. However, the phase composition is not much affected by the treatment time and the main coating phase is rutile with a smaller amount of anatase. Adding additional anatase in the form of particles increases the amount of anatase in the coatings. The additional particle addition has only minor effect on the corrosion resistance, but reduces the wear resistance remarkably. Interestingly, the addition of anatase particles and the PEO treatment time are not effective in increasing the photocatalytic activities of the samples. © 2020 The Author(s) |
Milikić, J; Martins, M; Dobrota, A S; Bozkurt, G; Soylu, G S P; Yurtcan, A B; Skorodumova, N V; Pašti, I A; Šljukić, B; Santos, D M F A Pt/MnV2O6 nanocomposite for the borohydride oxidation reaction Journal Article Journal of Energy Chemistry, 55 , pp. 428-436, 2021. @article{Milikić2021428, title = {A Pt/MnV2O6 nanocomposite for the borohydride oxidation reaction}, author = {J Milikić and M Martins and A S Dobrota and G Bozkurt and G S P Soylu and A B Yurtcan and N V Skorodumova and I A Pašti and B Šljukić and D M F Santos}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088976254&doi=10.1016%2fj.jechem.2020.07.029&partnerID=40&md5=cbef4fae08f02f4e851c1572814831f4}, doi = {10.1016/j.jechem.2020.07.029}, year = {2021}, date = {2021-01-01}, journal = {Journal of Energy Chemistry}, volume = {55}, pages = {428-436}, abstract = {Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts. Platinum supported on manganese vanadate (Pt/MnV2O6) was prepared by microwave irradiation method and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, and transmission electron microscopy. The borohydride oxidation reaction (BOR) on Pt/MnV2O6 was studied in highly alkaline media using voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. BOR electrocatalytic activity of Pt/MnV2O6 was also compared with that of commercial Pt/C (46 wt% Pt) electrocatalyst. The apparent activation energy of BOR at Pt/MnV2O6 was estimated to be 32 kJ mol−1 and the order of reaction to be 0.51, indicating that borohydride hydrolysis proceeds in parallel with its oxidation. Long-term stability of Pt/MnV2O6 under BOR typical conditions was observed. A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV2O6 anode reached a specific power of 274 W g−1. Experimental results on Pt/MnV2O6 were complemented by DFT calculations, which indicated good adherence of Pt to MnV2O6, beneficial for electrocatalyst stability. © 2020 Science Press}, keywords = {}, pubstate = {published}, tppubtype = {article} } Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts. Platinum supported on manganese vanadate (Pt/MnV2O6) was prepared by microwave irradiation method and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, and transmission electron microscopy. The borohydride oxidation reaction (BOR) on Pt/MnV2O6 was studied in highly alkaline media using voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. BOR electrocatalytic activity of Pt/MnV2O6 was also compared with that of commercial Pt/C (46 wt% Pt) electrocatalyst. The apparent activation energy of BOR at Pt/MnV2O6 was estimated to be 32 kJ mol−1 and the order of reaction to be 0.51, indicating that borohydride hydrolysis proceeds in parallel with its oxidation. Long-term stability of Pt/MnV2O6 under BOR typical conditions was observed. A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV2O6 anode reached a specific power of 274 W g−1. Experimental results on Pt/MnV2O6 were complemented by DFT calculations, which indicated good adherence of Pt to MnV2O6, beneficial for electrocatalyst stability. © 2020 Science Press |
Backović, G; Milikić, J; Negri, De S; Saccone, A; Šljukić, B; Santos, D M F Enhanced borohydride oxidation kinetics at gold-rare earth alloys Journal Article Journal of Alloys and Compounds, 857 , 2021. @article{Backović2021, title = {Enhanced borohydride oxidation kinetics at gold-rare earth alloys}, author = {G Backović and J Milikić and S De Negri and A Saccone and B Šljukić and D M F Santos}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098471175&doi=10.1016%2fj.jallcom.2020.158273&partnerID=40&md5=00af41c02a661f9561bfab7ea861591a}, doi = {10.1016/j.jallcom.2020.158273}, year = {2021}, date = {2021-01-01}, journal = {Journal of Alloys and Compounds}, volume = {857}, abstract = {Gold-rare earth (Au-RE) alloys with equiatomic compositions are prepared by arc (RE = Dy, Ho, Y) or induction (RE = Sm) melting. Morphology and phase composition is assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDXS), while X-ray powder diffraction (XRPD) is used to confirm crystal structures. The Au-RE electrodes are evaluated for borohydride oxidation reaction (BOR) in alkaline media employing cyclic voltammetry and chronoamperometry. The obtained data allows calculation of kinetic parameters that characterize the borohydride (BH4-) oxidation at Au-RE alloys, including the number of exchanged electrons, n, and the anodic charge transfer coefficient, α. n values range from 2.4 to 4.4, while α values are found to be in the 0.60–0.83 range. The BOR apparent activation energy, Eaapp, and the reaction order, β, are also determined from CV data obtained at different temperatures and different BH4- concentrations, respectively. Low Eaapp values range from 16.4 (Au-Sm) to 20.2 kJ mol−1 (Au-Y) and β values suggest that BOR at the examined alloys is a 1st order reaction with respect to BH-4 concentration. A small-scale direct borohydride-peroxide fuel cell (DBPFC) operating with Au-Y anode at 25 °C reaches a peak power density of 150 mW cm−2. The cell performance is enhanced when increasing the temperature to 45 °C, with a maximum power density of 215 mW cm−2 being attained. © 2020 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Gold-rare earth (Au-RE) alloys with equiatomic compositions are prepared by arc (RE = Dy, Ho, Y) or induction (RE = Sm) melting. Morphology and phase composition is assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDXS), while X-ray powder diffraction (XRPD) is used to confirm crystal structures. The Au-RE electrodes are evaluated for borohydride oxidation reaction (BOR) in alkaline media employing cyclic voltammetry and chronoamperometry. The obtained data allows calculation of kinetic parameters that characterize the borohydride (BH4-) oxidation at Au-RE alloys, including the number of exchanged electrons, n, and the anodic charge transfer coefficient, α. n values range from 2.4 to 4.4, while α values are found to be in the 0.60–0.83 range. The BOR apparent activation energy, Eaapp, and the reaction order, β, are also determined from CV data obtained at different temperatures and different BH4- concentrations, respectively. Low Eaapp values range from 16.4 (Au-Sm) to 20.2 kJ mol−1 (Au-Y) and β values suggest that BOR at the examined alloys is a 1st order reaction with respect to BH-4 concentration. A small-scale direct borohydride-peroxide fuel cell (DBPFC) operating with Au-Y anode at 25 °C reaches a peak power density of 150 mW cm−2. The cell performance is enhanced when increasing the temperature to 45 °C, with a maximum power density of 215 mW cm−2 being attained. © 2020 Elsevier B.V. |
Rakočević, L; Štrbac, S; Potočnik, J; Popović, M; Jugović, D; Simatović, I S The NaxMnO2 materials prepared by a glycine-nitrate method as advanced cathode materials for aqueous sodium-ion rechargeable batteries Journal Article Ceramics International, 47 (4), pp. 4595-4603, 2021. @article{Rakočević20214595, title = {The NaxMnO2 materials prepared by a glycine-nitrate method as advanced cathode materials for aqueous sodium-ion rechargeable batteries}, author = {L Rakočević and S Štrbac and J Potočnik and M Popović and D Jugović and I S Simatović}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092524965&doi=10.1016%2fj.ceramint.2020.10.025&partnerID=40&md5=c5fb13d9bf490a7a41250bdf2774f03c}, doi = {10.1016/j.ceramint.2020.10.025}, year = {2021}, date = {2021-01-01}, journal = {Ceramics International}, volume = {47}, number = {4}, pages = {4595-4603}, abstract = {Cathodic material for sodium-ion rechargeable batteries based on NaxMnO2 were synthesized by glycine nitrate method and subsequent annealing at high temperatures. Different crystal structures with different morphologies were obtained depending on the annealing temperature: hexagonal layeredα-Na0.7MnO2.05 nanoplates were obtained at 850 °C, while 3-D tunnel structured Na0·4MnO2 and Na0·44MnO2, both with rod-like morphology, were obtained at 800 °C and 900 °C, respectively. The investigations of the electrochemical behavior of obtained cathodic materials in aqueous NaNO3 solution have shown that Na0·44MnO2 obtained at 900 °C has shown the best battery performance. Its initial discharge capacities are 123.5 mA h/g, 113.2 mA h/g, and 102.0 mA h/g at the high current densities of 1000, 2000 and 5000 mA/g, respectively. © 2020 Elsevier Ltd and Techna Group S.r.l.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cathodic material for sodium-ion rechargeable batteries based on NaxMnO2 were synthesized by glycine nitrate method and subsequent annealing at high temperatures. Different crystal structures with different morphologies were obtained depending on the annealing temperature: hexagonal layeredα-Na0.7MnO2.05 nanoplates were obtained at 850 °C, while 3-D tunnel structured Na0·4MnO2 and Na0·44MnO2, both with rod-like morphology, were obtained at 800 °C and 900 °C, respectively. The investigations of the electrochemical behavior of obtained cathodic materials in aqueous NaNO3 solution have shown that Na0·44MnO2 obtained at 900 °C has shown the best battery performance. Its initial discharge capacities are 123.5 mA h/g, 113.2 mA h/g, and 102.0 mA h/g at the high current densities of 1000, 2000 and 5000 mA/g, respectively. © 2020 Elsevier Ltd and Techna Group S.r.l. |
Milanović, Ž B; Dimić, D S; Avdović, E H; Milenković, D A; Marković, J D; Klisurić, O R; Trifunović, S R; Marković, Z S Journal of Molecular Structure, 1225 , 2021. @article{Milanović2021, title = {Synthesis and comprehensive spectroscopic (X-ray, NMR, FTIR, UV–Vis), quantum chemical and molecular docking investigation of 3-acetyl-4‑hydroxy‑2-oxo-2H-chromen-7-yl acetate}, author = {Ž B Milanović and D S Dimić and E H Avdović and D A Milenković and J D Marković and O R Klisurić and S R Trifunović and Z S Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091333270&doi=10.1016%2fj.molstruc.2020.129256&partnerID=40&md5=b76a2735015b90a8a72fc522c3b26e40}, doi = {10.1016/j.molstruc.2020.129256}, year = {2021}, date = {2021-01-01}, journal = {Journal of Molecular Structure}, volume = {1225}, abstract = {In the present study, the structural, spectroscopic (FT-IR, NMR, and UV–Vis) and electronic properties of newly synthesized 3-acetyl-4‑hydroxy‑2-oxo-2H-chromen-7-yl acetate (3AcHyC) were determined by experimental and theoretical methods. The structural parameters (bond lengths and angles) were calculated using the B3LYP-D3BJ/6–311++G(d,p) theoretical model and compared with the experimentally determined crystal structure of the investigated compound. Hirshfeld surfaces and fingerprint plots analysis were used to find and analyze the percentage of intermolecular interactions in the crystal structure of the investigated compound. The calculated FT-IR frequencies were determined from the same theoretical model and matched with experimental data. The NMR chemical shifts (1H and 13C) were recorded in the CDCl3 solution and compared with theoretically determined spectra. The UV–Vis absorption spectrum was analyzed and compared with the spectrum calculated by Time-Dependent Density Functional Theory (TD-DFT). The obtained and compared spectroscopic data demonstrated that applied level theory reproduces well the experimental results. Furthermore, to examine the electronic structure of the studied molecule, the Natural Bond Orbitals (NBOs), the Quantum Theory of Atoms in Molecules (QTAIM), Non-linear Optical parameter (NLO), and Mapped Molecular Electrostatic Potential (MEP) surface analyses were also performed with the same level of theory. Furthermore, results of in silico molecular docking calculations, indicate the stability as well as favorable binding interactions between the investigated compound and the Tyrosyl DNA-Phosphodiesterase 1 (TDP1) active site. Also, the results indicate that the investigated compound is a favorable precursor in the synthesis of new coumarin derivatives with potentially significant biological and pharmacological properties. © 2020 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present study, the structural, spectroscopic (FT-IR, NMR, and UV–Vis) and electronic properties of newly synthesized 3-acetyl-4‑hydroxy‑2-oxo-2H-chromen-7-yl acetate (3AcHyC) were determined by experimental and theoretical methods. The structural parameters (bond lengths and angles) were calculated using the B3LYP-D3BJ/6–311++G(d,p) theoretical model and compared with the experimentally determined crystal structure of the investigated compound. Hirshfeld surfaces and fingerprint plots analysis were used to find and analyze the percentage of intermolecular interactions in the crystal structure of the investigated compound. The calculated FT-IR frequencies were determined from the same theoretical model and matched with experimental data. The NMR chemical shifts (1H and 13C) were recorded in the CDCl3 solution and compared with theoretically determined spectra. The UV–Vis absorption spectrum was analyzed and compared with the spectrum calculated by Time-Dependent Density Functional Theory (TD-DFT). The obtained and compared spectroscopic data demonstrated that applied level theory reproduces well the experimental results. Furthermore, to examine the electronic structure of the studied molecule, the Natural Bond Orbitals (NBOs), the Quantum Theory of Atoms in Molecules (QTAIM), Non-linear Optical parameter (NLO), and Mapped Molecular Electrostatic Potential (MEP) surface analyses were also performed with the same level of theory. Furthermore, results of in silico molecular docking calculations, indicate the stability as well as favorable binding interactions between the investigated compound and the Tyrosyl DNA-Phosphodiesterase 1 (TDP1) active site. Also, the results indicate that the investigated compound is a favorable precursor in the synthesis of new coumarin derivatives with potentially significant biological and pharmacological properties. © 2020 Elsevier B.V. |
Jevremović, A; Vasiljević, Nedić B; Popa, A; Uskoković-Marković, S; Ignjatović, L; Bajuk-Bogdanović, D; Milojević-Rakić, M The environmental impact of potassium tungstophosphate/ZSM-5 zeolite: Insight into catalysis and adsorption processes Journal Article Microporous and Mesoporous Materials, 315 , 2021. @article{Jevremović2021, title = {The environmental impact of potassium tungstophosphate/ZSM-5 zeolite: Insight into catalysis and adsorption processes}, author = {A Jevremović and B Nedić Vasiljević and A Popa and S Uskoković-Marković and L Ignjatović and D Bajuk-Bogdanović and M Milojević-Rakić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100434810&doi=10.1016%2fj.micromeso.2021.110925&partnerID=40&md5=1687c45405a8d6d7904cf4e692b01ed4}, doi = {10.1016/j.micromeso.2021.110925}, year = {2021}, date = {2021-01-01}, journal = {Microporous and Mesoporous Materials}, volume = {315}, abstract = {Environmental implementation of novel composite materials comprising potassium tungstophosphate (KPW) and ZSM-5 zeolite was tested in ethene production and pesticide removal. The study revealed that the binding of KPW to ZSM-5 zeolites of different Si/Al ratios affects the formation of active centres for catalytic and adsorption processes. Brønsted active sites present in the zeolite framework are synergistically joined with Lewis centres and additional Brønsted centres through the impregnation of potassium tungstophosphate, which resulted in improvement of stability and activity of investigated materials. Adsorption and catalytic performance were found to be influenced by the order of addition of salt precursors and by post-synthesis thermal treatment. The best results found both in ethanol dehydration and nicosulfuron removal were for the same sample of KPW supported at zeolite ZSM-5 (SiO2/Al2O3 = 30). The prominent ethanol conversion of 98% and the highest and most stable selectivity toward ethene were evidenced, along with the capacity of 28.4 mg of targeted pesticide retained per gram of designed KPW/ZSM composite. This comprehensive investigation enabled insight into active site formations in the efficient KPW/ZSM composites. Different approaches to implementation revealed that a lower Si/Al ratio in zeolite promotes efficient K+ exchange, which combined with two-phased in situ preparation of KPW as active phase, evidently leads to the formation of isolated sites of superior activity for both catalytic and adsorptive procedures. © 2021}, keywords = {}, pubstate = {published}, tppubtype = {article} } Environmental implementation of novel composite materials comprising potassium tungstophosphate (KPW) and ZSM-5 zeolite was tested in ethene production and pesticide removal. The study revealed that the binding of KPW to ZSM-5 zeolites of different Si/Al ratios affects the formation of active centres for catalytic and adsorption processes. Brønsted active sites present in the zeolite framework are synergistically joined with Lewis centres and additional Brønsted centres through the impregnation of potassium tungstophosphate, which resulted in improvement of stability and activity of investigated materials. Adsorption and catalytic performance were found to be influenced by the order of addition of salt precursors and by post-synthesis thermal treatment. The best results found both in ethanol dehydration and nicosulfuron removal were for the same sample of KPW supported at zeolite ZSM-5 (SiO2/Al2O3 = 30). The prominent ethanol conversion of 98% and the highest and most stable selectivity toward ethene were evidenced, along with the capacity of 28.4 mg of targeted pesticide retained per gram of designed KPW/ZSM composite. This comprehensive investigation enabled insight into active site formations in the efficient KPW/ZSM composites. Different approaches to implementation revealed that a lower Si/Al ratio in zeolite promotes efficient K+ exchange, which combined with two-phased in situ preparation of KPW as active phase, evidently leads to the formation of isolated sites of superior activity for both catalytic and adsorptive procedures. © 2021 |
Petrušić, I; Zidverc-Trajković, J Redefining types of migraine aura Journal Article Cephalalgia, 41 (2), pp. 274-275, 2021. @article{Petrušić2021274, title = {Redefining types of migraine aura}, author = {I Petrušić and J Zidverc-Trajković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85094884957&doi=10.1177%2f0333102420970186&partnerID=40&md5=8741e0f427377a9acdc927b2553a3c48}, doi = {10.1177/0333102420970186}, year = {2021}, date = {2021-01-01}, journal = {Cephalalgia}, volume = {41}, number = {2}, pages = {274-275}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Kuzmanovic, M; Stancalie, A; Milovanovic, D; Staicu, A; Damjanovic-Vasilic, L; Rankovic, D; Savovic, J Analysis of lead-based archaeological pottery glazes by laser induced breakdown spectroscopy Journal Article Optics and Laser Technology, 134 , 2021. @article{Kuzmanovic2021, title = {Analysis of lead-based archaeological pottery glazes by laser induced breakdown spectroscopy}, author = {M Kuzmanovic and A Stancalie and D Milovanovic and A Staicu and L Damjanovic-Vasilic and D Rankovic and J Savovic}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091080806&doi=10.1016%2fj.optlastec.2020.106599&partnerID=40&md5=2264d24c555783c05308db7492f1d1a4}, doi = {10.1016/j.optlastec.2020.106599}, year = {2021}, date = {2021-01-01}, journal = {Optics and Laser Technology}, volume = {134}, abstract = {The aim of this study was to demonstrate the potential of Laser-Induced Breakdown Spectroscopy (LIBS) in the analysis of pottery shards, which are commonly the most abundant artefacts recovered at archaeological sites. The analytical capability of LIBS in identification of elements characteristic to inorganic pigments used for decoration was assessed. Based on the specific elements detected in the LIBS spectra of glazes, correlations between the elemental composition of the glaze and the colours of the glazed surface were established. The results were in accordance with the previously reported Energy Dispersive X-ray Fluorescence (EDXRF) and Raman analyses of some of the samples, and with the presently performed XRF analysis. Two important parameters for plasma characterization, temperature and electron number density, were estimated from the spectral data. A potential use of LIBS for depth profiling was also investigated by analysing the silicon to aluminium intensity ratio as a function of the number of laser shots applied. Profilometry analysis of the damages created on the glazed surfaces by laser shots was used to estimate the average ablation depth and ablated mass. © 2020 Elsevier Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this study was to demonstrate the potential of Laser-Induced Breakdown Spectroscopy (LIBS) in the analysis of pottery shards, which are commonly the most abundant artefacts recovered at archaeological sites. The analytical capability of LIBS in identification of elements characteristic to inorganic pigments used for decoration was assessed. Based on the specific elements detected in the LIBS spectra of glazes, correlations between the elemental composition of the glaze and the colours of the glazed surface were established. The results were in accordance with the previously reported Energy Dispersive X-ray Fluorescence (EDXRF) and Raman analyses of some of the samples, and with the presently performed XRF analysis. Two important parameters for plasma characterization, temperature and electron number density, were estimated from the spectral data. A potential use of LIBS for depth profiling was also investigated by analysing the silicon to aluminium intensity ratio as a function of the number of laser shots applied. Profilometry analysis of the damages created on the glazed surfaces by laser shots was used to estimate the average ablation depth and ablated mass. © 2020 Elsevier Ltd |
Vujković, M J; Etinski, M; Vasić, B; Kuzmanović, B; Bajuk-Bogdanović, D; Dominko, R; Mentus, S Polyaniline as a charge storage material in an aqueous aluminum-based electrolyte: Can aluminum ions play the role of protons? Journal Article Journal of Power Sources, 482 , 2021. @article{Vujković2021, title = {Polyaniline as a charge storage material in an aqueous aluminum-based electrolyte: Can aluminum ions play the role of protons?}, author = {M J Vujković and M Etinski and B Vasić and B Kuzmanović and D Bajuk-Bogdanović and R Dominko and S Mentus}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091222062&doi=10.1016%2fj.jpowsour.2020.228937&partnerID=40&md5=bc783e11f3a2b9badbdef14b7eadac0f}, doi = {10.1016/j.jpowsour.2020.228937}, year = {2021}, date = {2021-01-01}, journal = {Journal of Power Sources}, volume = {482}, abstract = {The high redox activity of polyaniline emeraldine salt (PANI-ES) was revealed in the aqueous solution of Al-salt, which makes this polymer attractive as an electrode material for aqueous aluminum electrochemical storage devices. Its redox behavior in Al(NO3)3, Al(NO3)3+HCl, AlCl3 and HCl was investigated by Cyclic Voltammetry and Chronopotentiometry. While the proton exchange determines PANI's redox behavior in strong acidic solutions, anion doping/dedoping is a more dominant process in less acidic Al-salt solutions. The formation/dissolution of solid-state nitrate complexes is proposed to happen during PANI's redox switching in Al(NO3)3, which causes disappearance and reappearance of grain boundaries, as revealed by AFM. Combined experimental and DFT approaches identify Al-salt as a secondary dopant of protonated PANI-ES (by Lewis acid-base complexation), which causes polaron→bipolaron conversion. The change in the redox mechanism of PANI-ES, caused by the substitution of HCl with Al(NO3)3, did not attenuate its charge storage ability. Moreover, PANI-ES delivers a higher capacitance in Al(NO3)3, amounting to 269 F g−1 at 10 A g−1. Furthermore, the use of Al(NO3)3 results in attenuated electrochemical PANI overoxidation, when compared to HCl, thus providing better capacitance retention upon potentiodynamic cycling. The results open novel perspective of using PANI-based materials for more suitable energy storage devices. © 2020 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The high redox activity of polyaniline emeraldine salt (PANI-ES) was revealed in the aqueous solution of Al-salt, which makes this polymer attractive as an electrode material for aqueous aluminum electrochemical storage devices. Its redox behavior in Al(NO3)3, Al(NO3)3+HCl, AlCl3 and HCl was investigated by Cyclic Voltammetry and Chronopotentiometry. While the proton exchange determines PANI's redox behavior in strong acidic solutions, anion doping/dedoping is a more dominant process in less acidic Al-salt solutions. The formation/dissolution of solid-state nitrate complexes is proposed to happen during PANI's redox switching in Al(NO3)3, which causes disappearance and reappearance of grain boundaries, as revealed by AFM. Combined experimental and DFT approaches identify Al-salt as a secondary dopant of protonated PANI-ES (by Lewis acid-base complexation), which causes polaron→bipolaron conversion. The change in the redox mechanism of PANI-ES, caused by the substitution of HCl with Al(NO3)3, did not attenuate its charge storage ability. Moreover, PANI-ES delivers a higher capacitance in Al(NO3)3, amounting to 269 F g−1 at 10 A g−1. Furthermore, the use of Al(NO3)3 results in attenuated electrochemical PANI overoxidation, when compared to HCl, thus providing better capacitance retention upon potentiodynamic cycling. The results open novel perspective of using PANI-based materials for more suitable energy storage devices. © 2020 Elsevier B.V. |
Milanović, Z B; Antonijević, M R; Amić, A D; Avdović, E H; Dimić, D S; Milenković, D A; Marković, Z S RSC Advances, 11 (5), pp. 2838-2847, 2021. @article{Milanović20212838, title = {Inhibitory activity of quercetin, its metabolite, and standard antiviral drugs towards enzymes essential for SARS-CoV-2: The role of acid-base equilibria}, author = {Z B Milanović and M R Antonijević and A D Amić and E H Avdović and D S Dimić and D A Milenković and Z S Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099764622&doi=10.1039%2fd0ra09632f&partnerID=40&md5=c1b14a91e316378739c79c92c5955d75}, doi = {10.1039/d0ra09632f}, year = {2021}, date = {2021-01-01}, journal = {RSC Advances}, volume = {11}, number = {5}, pages = {2838-2847}, abstract = {The recently declared global pandemic of a new human coronavirus called SARS-CoV-2, which causes respiratory tract disease COVID-19, has reached worldwide resonance and global efforts are being made to look for possible cures. Sophisticated molecular docking software, as well as available protein sequence and structure information, offer the ability to test the inhibition of two important targets of SARS-CoV-2, furin (FUR) enzyme, and spike glycoprotein, or spike protein (SP), that are key to host cell adhesion and hijacking. The potential inhibitory effect and mechanism of action of acid-base forms of different antiviral drugs, dominant at physiological pH, chloroquine (CQ), hydroxychloroquine (HCQ), and cinanserin (CIN), which have been shown to be effective in the treatment of SARS-CoV-2 virus, is reported with the special emphasis on their relative abundances. On the other hand, the potential inhibitory effect of the dominant acid-base forms of quercetin (Q) and its oxidative metabolite 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H) benzofuranone (BZF), which are constituents of traditional food products believed to exhibit antiviral effects, was also examined. The undertaken study includes the determination of the major energy contributions to the binding energy as well as in-depth analysis of amino acid residues at the active pocket and possible interactions. The approach that we propose here may be an additional strategy for combating the deadly virus by preventing the first step of the virus replication cycle. Preliminary research has shown that the investigated compounds exert an inhibitory effect against the SARS-CoV-2 furin enzyme and spiked glycoprotein through different acid-base forms. These investigations may be helpful in creating potential therapeutic agents in the fight against the SARS-CoV-2 virus. On the other hand, the results we predicted in this computational study may be the basis for new experimental in vitro and in vivo studies. This journal is © 2021 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The recently declared global pandemic of a new human coronavirus called SARS-CoV-2, which causes respiratory tract disease COVID-19, has reached worldwide resonance and global efforts are being made to look for possible cures. Sophisticated molecular docking software, as well as available protein sequence and structure information, offer the ability to test the inhibition of two important targets of SARS-CoV-2, furin (FUR) enzyme, and spike glycoprotein, or spike protein (SP), that are key to host cell adhesion and hijacking. The potential inhibitory effect and mechanism of action of acid-base forms of different antiviral drugs, dominant at physiological pH, chloroquine (CQ), hydroxychloroquine (HCQ), and cinanserin (CIN), which have been shown to be effective in the treatment of SARS-CoV-2 virus, is reported with the special emphasis on their relative abundances. On the other hand, the potential inhibitory effect of the dominant acid-base forms of quercetin (Q) and its oxidative metabolite 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H) benzofuranone (BZF), which are constituents of traditional food products believed to exhibit antiviral effects, was also examined. The undertaken study includes the determination of the major energy contributions to the binding energy as well as in-depth analysis of amino acid residues at the active pocket and possible interactions. The approach that we propose here may be an additional strategy for combating the deadly virus by preventing the first step of the virus replication cycle. Preliminary research has shown that the investigated compounds exert an inhibitory effect against the SARS-CoV-2 furin enzyme and spiked glycoprotein through different acid-base forms. These investigations may be helpful in creating potential therapeutic agents in the fight against the SARS-CoV-2 virus. On the other hand, the results we predicted in this computational study may be the basis for new experimental in vitro and in vivo studies. This journal is © 2021 The Royal Society of Chemistry. |
Stanojević, A; Milovanović, B; Stanković, I; Etinski, M; Petković, M The significance of the metal cation in guanine-quartet - metalloporphyrin complexes Journal Article Physical chemistry chemical physics : PCCP, 23 (1), pp. 574-584, 2021. @article{Stanojević2021574, title = {The significance of the metal cation in guanine-quartet - metalloporphyrin complexes}, author = {A Stanojević and B Milovanović and I Stanković and M Etinski and M Petković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100125831&doi=10.1039%2fd0cp05798c&partnerID=40&md5=9d19d2256b272939139972d64f571154}, doi = {10.1039/d0cp05798c}, year = {2021}, date = {2021-01-01}, journal = {Physical chemistry chemical physics : PCCP}, volume = {23}, number = {1}, pages = {574-584}, abstract = {The planarity and the appropriate size of the porphyrin ring make porphyrin derivatives ideal ligands for stacking to guanine quartets and they could thus be used as anti-cancer drugs. In this contribution we analyzed complexes of a guanine quartet with a porphyrin molecule, magnesium porphyrin and calcium porphyrin. As magnesium and calcium ions are located in the center and above the porphyrin ring, respectively, the two metalloporphyrins are expected to have different impacts on the target. The optimized structures of the three systems revealed geometrical changes in the guanine quartet upon complexation: while stacking of porphyrin and magnesium porphyrin does not induce significant changes, calcium porphyrin considerably distorts the quartet's structure, which has significant implications for the binding properties among guanine molecules. Ab initio molecular dynamics simulations revealed that the systems perform small fluctuations around the equilibrium structures. The largest atom displacements are performed by the calcium ion. The interacting quantum atoms methodology enabled analysis of the binding properties in the studied complexes. Interestingly, although the proximity of the calcium ion is responsible for the quartet's pronounced deformation and weakening of guanine-guanine binding, it also enables stronger binding of the metal ion to the quartet, resulting in a more stable complex. These results imply that metalloporphyrin-like ligands with out-of-plane central ions might represent promising drug candidates in anti-tumor treatment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The planarity and the appropriate size of the porphyrin ring make porphyrin derivatives ideal ligands for stacking to guanine quartets and they could thus be used as anti-cancer drugs. In this contribution we analyzed complexes of a guanine quartet with a porphyrin molecule, magnesium porphyrin and calcium porphyrin. As magnesium and calcium ions are located in the center and above the porphyrin ring, respectively, the two metalloporphyrins are expected to have different impacts on the target. The optimized structures of the three systems revealed geometrical changes in the guanine quartet upon complexation: while stacking of porphyrin and magnesium porphyrin does not induce significant changes, calcium porphyrin considerably distorts the quartet's structure, which has significant implications for the binding properties among guanine molecules. Ab initio molecular dynamics simulations revealed that the systems perform small fluctuations around the equilibrium structures. The largest atom displacements are performed by the calcium ion. The interacting quantum atoms methodology enabled analysis of the binding properties in the studied complexes. Interestingly, although the proximity of the calcium ion is responsible for the quartet's pronounced deformation and weakening of guanine-guanine binding, it also enables stronger binding of the metal ion to the quartet, resulting in a more stable complex. These results imply that metalloporphyrin-like ligands with out-of-plane central ions might represent promising drug candidates in anti-tumor treatment. |
Mojović, Z; Petrović, S; Mojović, M; Pavlović, S; Rožić, L Ruthenium containing perovskites as electrode materials for 4-nitrophenol detection Journal Article Journal of Physics and Chemistry of Solids, 148 , 2021. @article{Mojović2021, title = {Ruthenium containing perovskites as electrode materials for 4-nitrophenol detection}, author = {Z Mojović and S Petrović and M Mojović and S Pavlović and L Rožić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089660184&doi=10.1016%2fj.jpcs.2020.109649&partnerID=40&md5=2178ca9e6a6a97bf29af47c7530f08d5}, doi = {10.1016/j.jpcs.2020.109649}, year = {2021}, date = {2021-01-01}, journal = {Journal of Physics and Chemistry of Solids}, volume = {148}, abstract = {In this paper, the relationship of structure, type of oxygen defects, valence states of Cr and Ru, and electrochemical properties of La0.7Sr0.3Cr1-XRuXO3 (0 < x < 0.1) perovskite-type oxides were studied. The samples were synthesized by a conventional solid-state reaction method and characterized by powder X-ray diffraction, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and electron paramagnetic resonance spectroscopy. The electrochemical performance of these samples was evaluated towards the detection of 4-nitrophenol and strongly depends on the concentration of ruthenium incorporated in the crystal lattice. A new La0.7Sr0.3Cr0.925Ru0.075O3 electrocatalyst with a wide linear concentration range (25–5000 mM) and a detection limit of 8 mM was obtained. These results provide an opportunity for its application in the analysis of real water samples. © 2020 Elsevier Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, the relationship of structure, type of oxygen defects, valence states of Cr and Ru, and electrochemical properties of La0.7Sr0.3Cr1-XRuXO3 (0 < x < 0.1) perovskite-type oxides were studied. The samples were synthesized by a conventional solid-state reaction method and characterized by powder X-ray diffraction, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and electron paramagnetic resonance spectroscopy. The electrochemical performance of these samples was evaluated towards the detection of 4-nitrophenol and strongly depends on the concentration of ruthenium incorporated in the crystal lattice. A new La0.7Sr0.3Cr0.925Ru0.075O3 electrocatalyst with a wide linear concentration range (25–5000 mM) and a detection limit of 8 mM was obtained. These results provide an opportunity for its application in the analysis of real water samples. © 2020 Elsevier Ltd |
Vasić, M M; Žák, T; Pizúrová, N; Simatović, I S; Minić, D M Influence of Thermal Treatment on Microstructure and Corrosion Behavior of Amorphous Fe40Ni40B12Si8 Alloy Journal Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 52 (1), pp. 34-45, 2021. @article{Vasić202134, title = {Influence of Thermal Treatment on Microstructure and Corrosion Behavior of Amorphous Fe40Ni40B12Si8 Alloy}, author = {M M Vasić and T Žák and N Pizúrová and I S Simatović and D M Minić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096190397&doi=10.1007%2fs11661-020-06079-3&partnerID=40&md5=7838d3136c0bdafafe0839f937d31669}, doi = {10.1007/s11661-020-06079-3}, year = {2021}, date = {2021-01-01}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {52}, number = {1}, pages = {34-45}, abstract = {Microstructural evolution of thermally treated melt-quenched amorphous Fe40Ni40B12Si8 alloy was studied in terms of its influence on corrosion behavior of the alloy. Alloy structure was transformed gradually from purely amorphous and chemically homogeneous to fully crystalline, yielding γ-(Fe,Ni), Ni31Si12 and (Fe,Ni)2B phases as the final products. Corrosion study of the alloy in amorphous, partially crystalline as well as fully crystalline form, performed by electrochemical measurements in 0.5 M NaCl, together with the morphology examination, revealed that the microstructure and phase composition are crucial factors determining the corrosion resistance of the alloy in corrosive environment. © 2020, The Minerals, Metals & Materials Society and ASM International.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Microstructural evolution of thermally treated melt-quenched amorphous Fe40Ni40B12Si8 alloy was studied in terms of its influence on corrosion behavior of the alloy. Alloy structure was transformed gradually from purely amorphous and chemically homogeneous to fully crystalline, yielding γ-(Fe,Ni), Ni31Si12 and (Fe,Ni)2B phases as the final products. Corrosion study of the alloy in amorphous, partially crystalline as well as fully crystalline form, performed by electrochemical measurements in 0.5 M NaCl, together with the morphology examination, revealed that the microstructure and phase composition are crucial factors determining the corrosion resistance of the alloy in corrosive environment. © 2020, The Minerals, Metals & Materials Society and ASM International. |
Koturevic, B; Adnadjevic, B; Jovanovic, J Chemical Engineering Research and Design, 165 , pp. 106-117, 2021. @article{Koturevic2021106, title = {Comparative kinetic analysis of total hypericin extraction from Hypericum perforatum flowers carried out under simultaneous external physical field and cooling reaction system operational conditions}, author = {B Koturevic and B Adnadjevic and J Jovanovic}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096237598&doi=10.1016%2fj.cherd.2020.10.025&partnerID=40&md5=99bf6c9ac46ab6c808c1dbbf2edc8b06}, doi = {10.1016/j.cherd.2020.10.025}, year = {2021}, date = {2021-01-01}, journal = {Chemical Engineering Research and Design}, volume = {165}, pages = {106-117}, abstract = {The comparative kinetic analysis of total hypericin (TH) extraction from the pre-extracted flowers of Hypericum perforatum carried out under simultaneous external physical field and cooling reaction system operational conditions (SEPFC) was performed. The kinetics curves of TH extraction in SEPFC were measured in the temperature range from T = 298 to 328 K. It was proved that presence of ultrasonic and microwave field cause increasing of the extraction rate compared to conventional isothermal extraction. The possibility of describing the kinetics of TH extraction in SEPFC with empirical (Elovich's model) and physically-based (film-theory model) were explored. The kinetic complexity of the process was examined with the differential isoconversional method. By applying the model-fitting method the proper kinetic model of TH extraction in SEPFC was found: [1 − (1 − α)(1/3)]2 = kM · t. The values of the extraction rate constant (kM), activation energy (Ea) and pre-exponential factor (ln A) of TH extraction were calculated. The effect of ultrasonic and microwave field on (a) kM; (b) Ea and (c) ln A of TH extraction was determined. The model mechanism of activation of hypericin molecule for extraction in SEPFC conditions was proposed. The values of wave number of resonant vibrations, vibration quantum number and anharmonicity parameter for the TH extraction are obtained. © 2020 Institution of Chemical Engineers}, keywords = {}, pubstate = {published}, tppubtype = {article} } The comparative kinetic analysis of total hypericin (TH) extraction from the pre-extracted flowers of Hypericum perforatum carried out under simultaneous external physical field and cooling reaction system operational conditions (SEPFC) was performed. The kinetics curves of TH extraction in SEPFC were measured in the temperature range from T = 298 to 328 K. It was proved that presence of ultrasonic and microwave field cause increasing of the extraction rate compared to conventional isothermal extraction. The possibility of describing the kinetics of TH extraction in SEPFC with empirical (Elovich's model) and physically-based (film-theory model) were explored. The kinetic complexity of the process was examined with the differential isoconversional method. By applying the model-fitting method the proper kinetic model of TH extraction in SEPFC was found: [1 − (1 − α)(1/3)]2 = kM · t. The values of the extraction rate constant (kM), activation energy (Ea) and pre-exponential factor (ln A) of TH extraction were calculated. The effect of ultrasonic and microwave field on (a) kM; (b) Ea and (c) ln A of TH extraction was determined. The model mechanism of activation of hypericin molecule for extraction in SEPFC conditions was proposed. The values of wave number of resonant vibrations, vibration quantum number and anharmonicity parameter for the TH extraction are obtained. © 2020 Institution of Chemical Engineers |
Milikić, J; Balčiūnaitė, A; Sukackienė, Z; Mladenović, D; Santos, D M F; Tamašauskaitė-Tamašiūnaitė, L; Šljukić, B Bimetallic co-based (Com Journal Article Materials, 14 (1), pp. 1-15, 2021. @article{Milikić20211, title = {Bimetallic co-based (Com}, author = {J Milikić and A Balčiūnaitė and Z Sukackienė and D Mladenović and D M F Santos and L Tamašauskaitė-Tamašiūnaitė and B Šljukić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098596435&doi=10.3390%2fma14010092&partnerID=40&md5=ac07589c38b1f55f96ef3a742f5e9f1f}, doi = {10.3390/ma14010092}, year = {2021}, date = {2021-01-01}, journal = {Materials}, volume = {14}, number = {1}, pages = {1-15}, abstract = {Bimetallic cobalt (Co)-based coatings were prepared by a facile, fast, and low-cost electroless deposition on a copper substrate (CoFe, CoMn, CoMo) and characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Prepared coatings were thoroughly examined for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution (1 M potassium hydroxide, KOH) and their activity compared to that of Co and Ni coatings. All five coatings showed activity for both reactions, where CoMo and Co showed the highest activity for HER and OER, respectively. Namely, the highest HER current density was recorded at CoMo coating with low overpotential (61 mV) to reach a current density of 10 mA·cm−2 . The highest OER current density was recorded at Co coating with a low Tafel slope of 60 mV·dec−1 . Furthermore, these coatings proved to be stable under HER and OER polarization conditions. © 2020 by the authors. Li-censee MDPI, Basel, Switzerland.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Bimetallic cobalt (Co)-based coatings were prepared by a facile, fast, and low-cost electroless deposition on a copper substrate (CoFe, CoMn, CoMo) and characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Prepared coatings were thoroughly examined for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution (1 M potassium hydroxide, KOH) and their activity compared to that of Co and Ni coatings. All five coatings showed activity for both reactions, where CoMo and Co showed the highest activity for HER and OER, respectively. Namely, the highest HER current density was recorded at CoMo coating with low overpotential (61 mV) to reach a current density of 10 mA·cm−2 . The highest OER current density was recorded at Co coating with a low Tafel slope of 60 mV·dec−1 . Furthermore, these coatings proved to be stable under HER and OER polarization conditions. © 2020 by the authors. Li-censee MDPI, Basel, Switzerland. |
Grippo, V; Mojovic, M; Pavicevic, A; Kabelac, M; Hubatka, F; Turanek, J; Zatloukalova, M; Freeman, B A; Vacek, J Electrophilic characteristics and aqueous behavior of fatty acid nitroalkenes Journal Article Redox Biology, 38 , 2021. @article{Grippo2021, title = {Electrophilic characteristics and aqueous behavior of fatty acid nitroalkenes}, author = {V Grippo and M Mojovic and A Pavicevic and M Kabelac and F Hubatka and J Turanek and M Zatloukalova and B A Freeman and J Vacek}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096158093&doi=10.1016%2fj.redox.2020.101756&partnerID=40&md5=2da8f31c4fb805691910ec16078ae42b}, doi = {10.1016/j.redox.2020.101756}, year = {2021}, date = {2021-01-01}, journal = {Redox Biology}, volume = {38}, abstract = {Fatty acid nitroalkenes (NO2-FA) are endogenously-generated products of the reaction of metabolic and inflammatory-derived nitrogen dioxide (.NO2) with unsaturated fatty acids. These species mediate signaling actions and induce adaptive responses in preclinical models of inflammatory and metabolic diseases. The nitroalkene substituent possesses an electrophilic nature, resulting in rapid and reversible reactions with biological nucleophiles such as cysteine, thus supporting post-translational modifications (PTM) of proteins having susceptible nucleophilic centers. These reactions contribute to enzyme regulation, modulation of inflammation and cell proliferation and the regulation of gene expression responses. Herein, focus is placed on the reduction-oxidation (redox) characteristics and stability of specific NO2-FA regioisomers having biological and clinical relevance; nitro-oleic acid (NO2-OA), bis-allylic nitro-linoleic acid (NO2-LA) and the conjugated diene-containing nitro-conjugated linoleic acid (NO2-cLA). Cyclic and alternating-current voltammetry and chronopotentiometry were used to the study of reduction potentials of these NO2-FA. R–NO2 reduction was observed around −0.8 V (vs. Ag/AgCl/3 M KCl) and is related to relative NO2-FA electrophilicity. This reduction process could be utilized for the evaluation of NO2-FA stability in aqueous milieu, shown herein to be pH dependent. In addition, electron paramagnetic resonance (EPR) spectroscopy was used to define the stability of the nitroalkene moiety under aqueous conditions, specifically under conditions where nitric oxide (.NO) release could be detected. The experimental data were supported by density functional theory calculations using 6–311++G (d,p) basis set and B3LYP functional. Based on experimental and computational approaches, the relative electrophilicities of these NO2-FA are NO2-cLA >> NO2-LA > NO2-OA. Micellarization and vesiculation largely define these biophysical characteristics in aqueous, nucleophile-free conditions. At concentrations below the critical micellar concentration (CMC), monomeric NO2-FA predominate, while at greater concentrations a micellar phase consisting of self-assembled lipid structures predominates. The CMC, determined by dynamic light scattering in 0.1 M phosphate buffer (pH 7.4) at 25 °C, was 6.9 (NO2-LA) 10.6 (NO2-OA) and 42.3 μM (NO2-cLA), respectively. In aggregate, this study provides new insight into the biophysical properties of NO2-FA that are important for better understanding the cell signaling and pharmacological potential of this class of mediators. © 2020 The Authors}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fatty acid nitroalkenes (NO2-FA) are endogenously-generated products of the reaction of metabolic and inflammatory-derived nitrogen dioxide (.NO2) with unsaturated fatty acids. These species mediate signaling actions and induce adaptive responses in preclinical models of inflammatory and metabolic diseases. The nitroalkene substituent possesses an electrophilic nature, resulting in rapid and reversible reactions with biological nucleophiles such as cysteine, thus supporting post-translational modifications (PTM) of proteins having susceptible nucleophilic centers. These reactions contribute to enzyme regulation, modulation of inflammation and cell proliferation and the regulation of gene expression responses. Herein, focus is placed on the reduction-oxidation (redox) characteristics and stability of specific NO2-FA regioisomers having biological and clinical relevance; nitro-oleic acid (NO2-OA), bis-allylic nitro-linoleic acid (NO2-LA) and the conjugated diene-containing nitro-conjugated linoleic acid (NO2-cLA). Cyclic and alternating-current voltammetry and chronopotentiometry were used to the study of reduction potentials of these NO2-FA. R–NO2 reduction was observed around −0.8 V (vs. Ag/AgCl/3 M KCl) and is related to relative NO2-FA electrophilicity. This reduction process could be utilized for the evaluation of NO2-FA stability in aqueous milieu, shown herein to be pH dependent. In addition, electron paramagnetic resonance (EPR) spectroscopy was used to define the stability of the nitroalkene moiety under aqueous conditions, specifically under conditions where nitric oxide (.NO) release could be detected. The experimental data were supported by density functional theory calculations using 6–311++G (d,p) basis set and B3LYP functional. Based on experimental and computational approaches, the relative electrophilicities of these NO2-FA are NO2-cLA >> NO2-LA > NO2-OA. Micellarization and vesiculation largely define these biophysical characteristics in aqueous, nucleophile-free conditions. At concentrations below the critical micellar concentration (CMC), monomeric NO2-FA predominate, while at greater concentrations a micellar phase consisting of self-assembled lipid structures predominates. The CMC, determined by dynamic light scattering in 0.1 M phosphate buffer (pH 7.4) at 25 °C, was 6.9 (NO2-LA) 10.6 (NO2-OA) and 42.3 μM (NO2-cLA), respectively. In aggregate, this study provides new insight into the biophysical properties of NO2-FA that are important for better understanding the cell signaling and pharmacological potential of this class of mediators. © 2020 The Authors |
2020 |
Goura, J; Sundar, A; Bassil, B S; Ćirić-Marjanović, G; Bajuk-Bogdanović, D; Kortz, U Peroxouranyl-Containing W48 Wheel: Synthesis, Structure, and Detailed Infrared and Raman Spectroscopy Study Journal Article Inorganic Chemistry, 59 (23), pp. 16789-16794, 2020. @article{Goura202016789, title = {Peroxouranyl-Containing W48 Wheel: Synthesis, Structure, and Detailed Infrared and Raman Spectroscopy Study}, author = {J Goura and A Sundar and B S Bassil and G Ćirić-Marjanović and D Bajuk-Bogdanović and U Kortz}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097584294&doi=10.1021%2facs.inorgchem.0c02858&partnerID=40&md5=2094ea108467b3fc57b160fbff1ccd99}, doi = {10.1021/acs.inorgchem.0c02858}, year = {2020}, date = {2020-01-01}, journal = {Inorganic Chemistry}, volume = {59}, number = {23}, pages = {16789-16794}, abstract = {We report on the first example of a peroxouranium-containing P8W48 wheel, [(UO2)4(O2)42(P8W48O184)]40- (1), which was synthesized by a one-pot reaction of UO2(NO3)2·6H2O with the 48-tungsto-8-phosphate wheel [H7P8W48O184]33- and aqueous hydrogen peroxide in a pH 6 lithium acetate solution at 50 °C. Polyanion 1 comprises two tetrauranyl squares with side-on peroxo bridging ligands in the cavity of the P8W48 wheel, and was isolated as the hydrated potassium-lithium salt K18Li22[(UO2)4(O2)42(P8W48O184)]·133H2O (KLi-1), which was characterized in the solid state by single-crystal X-ray diffraction, as well as thermogravimetric and elemental analyses. A detailed Fourier transform infrared and Raman spectroscopy study was also performed. © 2020 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on the first example of a peroxouranium-containing P8W48 wheel, [(UO2)4(O2)42(P8W48O184)]40- (1), which was synthesized by a one-pot reaction of UO2(NO3)2·6H2O with the 48-tungsto-8-phosphate wheel [H7P8W48O184]33- and aqueous hydrogen peroxide in a pH 6 lithium acetate solution at 50 °C. Polyanion 1 comprises two tetrauranyl squares with side-on peroxo bridging ligands in the cavity of the P8W48 wheel, and was isolated as the hydrated potassium-lithium salt K18Li22[(UO2)4(O2)42(P8W48O184)]·133H2O (KLi-1), which was characterized in the solid state by single-crystal X-ray diffraction, as well as thermogravimetric and elemental analyses. A detailed Fourier transform infrared and Raman spectroscopy study was also performed. © 2020 American Chemical Society. |
Stanković, B; Jovanović, J; Adnađević, B The kinetics of non-isothermal dehydration of equilibrium swollen Ca-alginate hydrogel Journal Article Journal of Thermal Analysis and Calorimetry, 142 (5), pp. 2123-2129, 2020. @article{Stanković20202123, title = {The kinetics of non-isothermal dehydration of equilibrium swollen Ca-alginate hydrogel}, author = {B Stanković and J Jovanović and B Adnađević}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088256033&doi=10.1007%2fs10973-020-10020-6&partnerID=40&md5=e3b9fed5a780db8cdea4a0d8f8bec2f6}, doi = {10.1007/s10973-020-10020-6}, year = {2020}, date = {2020-01-01}, journal = {Journal of Thermal Analysis and Calorimetry}, volume = {142}, number = {5}, pages = {2123-2129}, abstract = {Non-isothermal dehydration of Ca-alginate hydrogel was investigated for the first time. Thermogravimetric dehydration curves were recorded at heating rates from 5 to 20 K min−1 in the temperature range from 300 to 450 K. The dependence of apparent activation energy on the degree of dehydration was determined by the Friedman’s differential isoconversion method. The experimental conversion curves of dehydration are fully fitted with the statistical model of hydrogel dehydration. The values of the parameters of the statistical model and their changes with the heating rate were determined. The rate constant as the function of temperature was calculated at all heating rates, and it was found that these dependencies obey the Arrhenius equation. From the values of rate constant, the changes in the kinetic parameters (activation energy and pre-exponential factor) of non-isothermal dehydration of Ca-alginate hydrogel with temperature and dehydration degree were calculated. The obtained results indicate the existence of two phase states of water absorbed on the hydrogel. © 2020, Akadémiai Kiadó, Budapest, Hungary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Non-isothermal dehydration of Ca-alginate hydrogel was investigated for the first time. Thermogravimetric dehydration curves were recorded at heating rates from 5 to 20 K min−1 in the temperature range from 300 to 450 K. The dependence of apparent activation energy on the degree of dehydration was determined by the Friedman’s differential isoconversion method. The experimental conversion curves of dehydration are fully fitted with the statistical model of hydrogel dehydration. The values of the parameters of the statistical model and their changes with the heating rate were determined. The rate constant as the function of temperature was calculated at all heating rates, and it was found that these dependencies obey the Arrhenius equation. From the values of rate constant, the changes in the kinetic parameters (activation energy and pre-exponential factor) of non-isothermal dehydration of Ca-alginate hydrogel with temperature and dehydration degree were calculated. The obtained results indicate the existence of two phase states of water absorbed on the hydrogel. © 2020, Akadémiai Kiadó, Budapest, Hungary. |
Nešović, M; Gašić, U; Tosti, T; Horvacki, N; Šikoparija, B; Nedić, N; Blagojević, S; Ignjatović, L; Tešić, Ž Polyphenol profile of buckwheat honey, nectar and pollen: Polyphenolics in buckwheat Journal Article Royal Society Open Science, 7 (12), 2020. @article{Nešović2020, title = {Polyphenol profile of buckwheat honey, nectar and pollen: Polyphenolics in buckwheat}, author = {M Nešović and U Gašić and T Tosti and N Horvacki and B Šikoparija and N Nedić and S Blagojević and L Ignjatović and Ž Tešić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099572647&doi=10.1098%2frsos.201576rsos201576&partnerID=40&md5=2c3381b727674f9c1213bee29f4cf575}, doi = {10.1098/rsos.201576rsos201576}, year = {2020}, date = {2020-01-01}, journal = {Royal Society Open Science}, volume = {7}, number = {12}, abstract = {A focus of research in recent years is the comparison of honey as the final product of bees with pollen and nectar of the plant from which the honey originates, as the main food source for bees. Buckwheat honey is recognized as a nutritionally valuable product, which provides a scientifically proven health benefit and is confirmed as a functional food. The quality of this type of honey is attributed to high levels of phytochemicals in buckwheat. The purpose of this study was the examination of similarity between buckwheat honey and buckwheat nectar and pollen, as well as simultaneous investigation of their chemical profiles and the origin of the honey. The phenolic profile of buckwheat pollen showed a lower number of flavonoids and phenolic acids than those of nectar and honey samples, but confirmed the presence of the most characteristic polyphenols derived from the buckwheat plant. The notable difference was found to be the presence of (epi)catechin units, its galloylated derivatives and procyanidin dimers, which were not present in honey. Honey polyphenols displayed a pronounced correlation with those of nectar, but not with those of pollen. Finally, by comparing the polyphenolic profiles of honey, nectar and pollen sharing the same geographical origin, new data could be provided for a potential assessment of the botanical origin of buckwheat honey. © 2020 The Authors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A focus of research in recent years is the comparison of honey as the final product of bees with pollen and nectar of the plant from which the honey originates, as the main food source for bees. Buckwheat honey is recognized as a nutritionally valuable product, which provides a scientifically proven health benefit and is confirmed as a functional food. The quality of this type of honey is attributed to high levels of phytochemicals in buckwheat. The purpose of this study was the examination of similarity between buckwheat honey and buckwheat nectar and pollen, as well as simultaneous investigation of their chemical profiles and the origin of the honey. The phenolic profile of buckwheat pollen showed a lower number of flavonoids and phenolic acids than those of nectar and honey samples, but confirmed the presence of the most characteristic polyphenols derived from the buckwheat plant. The notable difference was found to be the presence of (epi)catechin units, its galloylated derivatives and procyanidin dimers, which were not present in honey. Honey polyphenols displayed a pronounced correlation with those of nectar, but not with those of pollen. Finally, by comparing the polyphenolic profiles of honey, nectar and pollen sharing the same geographical origin, new data could be provided for a potential assessment of the botanical origin of buckwheat honey. © 2020 The Authors. |
