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| 1. | Pašti, I A; Mentus, S V: “Spot the difference”—just a game or the game-changer?. In: Joule, 5 (3), pp. 519-521, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Pašti2021519, title = {“Spot the difference”—just a game or the game-changer?}, author = {I A Pašti and S V Mentus}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102377113&doi=10.1016%2fj.joule.2021.02.017&partnerID=40&md5=df34ce06e7a1179b8a047a94c1e65a66}, doi = {10.1016/j.joule.2021.02.017}, year = {2021}, date = {2021-01-01}, journal = {Joule}, volume = {5}, number = {3}, pages = {519-521}, abstract = {Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. |
| 2. | Mojović, Z; Petrović, S; Mojović, M; Pavlović, S; Rožić, L: Ruthenium containing perovskites as electrode materials for 4-nitrophenol detection. In: Journal of Physics and Chemistry of Solids, 148 , 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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 |
| 3. | 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. In: Redox Biology, 38 , 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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 |
| 4. | 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. In: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 52 (1), pp. 34-45, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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. |
| 5. | Koturevic, B; Adnadjevic, B; Jovanovic, J: Comparative kinetic analysis of total hypericin extraction from Hypericum perforatum flowers carried out under simultaneous external physical field and cooling reaction system operational conditions. In: Chemical Engineering Research and Design, 165 , pp. 106-117, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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 |
| 6. | Milikić, J; Balčiūnaitė, A; Sukackienė, Z; Mladenović, D; Santos, D M F; Tamašauskaitė-Tamašiūnaitė, L; Šljukić, B: Bimetallic co-based (Com. In: Materials, 14 (1), pp. 1-15, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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. |
| 7. | Ignjatović, S; Blawert, C; Serdechnova, M; Karpushenkov, S; Damjanović, M; Karlova, P; Dovzhenko, G; Wieland, D C F; Zeller-Plumhoff, B; Starykevich, M; Stojanović, S; Damjanović-Vasilić, L; Zheludkevich, M L: The Influence of In Situ Anatase Particle Addition on the Formation and Properties of Multifunctional Plasma Electrolytic Oxidation Coatings on AA2024 Aluminum Alloy. In: Advanced Engineering Materials, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Ignjatović2021b, title = {The Influence of In Situ Anatase Particle Addition on the Formation and Properties of Multifunctional Plasma Electrolytic Oxidation Coatings on AA2024 Aluminum Alloy}, author = {S Ignjatović and C Blawert and M Serdechnova and S Karpushenkov and M Damjanović and P Karlova and G Dovzhenko and D C F Wieland and B Zeller-Plumhoff and M Starykevich and S Stojanović and L Damjanović-Vasilić and M L Zheludkevich}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103078141&doi=10.1002%2fadem.202001527&partnerID=40&md5=f0908c6cbfc49b742c83fddd4d92daa5}, doi = {10.1002/adem.202001527}, year = {2021}, date = {2021-01-01}, journal = {Advanced Engineering Materials}, abstract = {Plasma electrolytic oxidation (PEO) with in situ anatase particle addition is applied to functionalize the surface of AA2024 alloy. A base potassium titanium oxide oxalate dihydrate aqueous electrolyte is used with up to 30 g L−1 anatase particle addition. The coatings’ morphology and phase composition as a function of the anatase concentration in the electrolyte are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES). Photocatalytic activity, stability in chloride solution, and tribological properties are also determined. The main coating forming phases are anatase and rutile on top of a mixed interface region consisting of TiAl2O5 as reaction product between the TiO2 and an Al2O3 barrier layer on top of the Al substrate. The mixed layer is extending with increasing amount of particles added, due to intensified discharges. In addition, anatase-to-rutile phase ratio increases due to the additional anatase particles in the electrolyte. Thus, the photocatalytic activity is improving with the particle addition. The coatings’ mechanical resistance is dropping first before increasing again with more particles added. Chemical and restored mechanical stability seems to be related to the extended mixed interface formation, which strengthens the bond to the substrate when more particles are added. © 2021 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plasma electrolytic oxidation (PEO) with in situ anatase particle addition is applied to functionalize the surface of AA2024 alloy. A base potassium titanium oxide oxalate dihydrate aqueous electrolyte is used with up to 30 g L−1 anatase particle addition. The coatings’ morphology and phase composition as a function of the anatase concentration in the electrolyte are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES). Photocatalytic activity, stability in chloride solution, and tribological properties are also determined. The main coating forming phases are anatase and rutile on top of a mixed interface region consisting of TiAl2O5 as reaction product between the TiO2 and an Al2O3 barrier layer on top of the Al substrate. The mixed layer is extending with increasing amount of particles added, due to intensified discharges. In addition, anatase-to-rutile phase ratio increases due to the additional anatase particles in the electrolyte. Thus, the photocatalytic activity is improving with the particle addition. The coatings’ mechanical resistance is dropping first before increasing again with more particles added. Chemical and restored mechanical stability seems to be related to the extended mixed interface formation, which strengthens the bond to the substrate when more particles are added. © 2021 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH |
| 8. | Vasić, M M; Žák, T; Minić, D M: Kinetics and influence of thermally induced crystallization of Fe,Ni-containing phases on thermomagnetic properties of Fe40Ni40B12Si8 amorphous alloy. In: Journal of Thermal Analysis and Calorimetry, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Vasić2021, title = {Kinetics and influence of thermally induced crystallization of Fe,Ni-containing phases on thermomagnetic properties of Fe40Ni40B12Si8 amorphous alloy}, author = {M M Vasić and T Žák and D M Minić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104519208&doi=10.1007%2fs10973-021-10819-x&partnerID=40&md5=3b45d292fcdc3c963d41874830a1af9a}, doi = {10.1007/s10973-021-10819-x}, year = {2021}, date = {2021-01-01}, journal = {Journal of Thermal Analysis and Calorimetry}, abstract = {Thermal treatment of Fe40Ni40B12Si8 amorphous alloy leads to crystallization of various Fe and Ni-containing phases and their recrystallization, affecting the functional properties of the alloy. Kinetics of multistep crystallization of Fe40Ni40B12Si8 amorphous alloy and influence of thermally induced microstructural transformations on magnetic moment of the alloy were studied by means of structural examination, thermal analysis and thermomagnetic measurements. Temperature regions of growth and loss of magnetic moment of the alloy were correlated with the microstructural changes. Curie temperatures of the alloy in fully amorphous and fully crystallized form were observed at 620 and 910 K, respectively. Detailed kinetic study including deconvolution of the complex exothermic DTA peaks yielded Arrhenius parameters and kinetic model of individual crystallization steps, which reflect the nature of the studied processes and the alloy chemical composition. The obtained parameters and kinetic models can be used for kinetic predictions of thermal stability and functionality of the alloy. © 2021, Akadémiai Kiadó, Budapest, Hungary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thermal treatment of Fe40Ni40B12Si8 amorphous alloy leads to crystallization of various Fe and Ni-containing phases and their recrystallization, affecting the functional properties of the alloy. Kinetics of multistep crystallization of Fe40Ni40B12Si8 amorphous alloy and influence of thermally induced microstructural transformations on magnetic moment of the alloy were studied by means of structural examination, thermal analysis and thermomagnetic measurements. Temperature regions of growth and loss of magnetic moment of the alloy were correlated with the microstructural changes. Curie temperatures of the alloy in fully amorphous and fully crystallized form were observed at 620 and 910 K, respectively. Detailed kinetic study including deconvolution of the complex exothermic DTA peaks yielded Arrhenius parameters and kinetic model of individual crystallization steps, which reflect the nature of the studied processes and the alloy chemical composition. The obtained parameters and kinetic models can be used for kinetic predictions of thermal stability and functionality of the alloy. © 2021, Akadémiai Kiadó, Budapest, Hungary. |
| 9. | Avdović, E H; Petrović, I P; Stevanović, M J; Saso, L; Marković, Dimitrić J M; Filipović, N D; Živić, M Ž; Antić, Cvetić T N; Žižić, M V; Todorović, N V; Vukić, M; Trifunović, S R; Marković, Z S: Synthesis and Biological Screening of New 4-Hydroxycoumarin Derivatives and Their Palladium(II) Complexes. In: Oxidative Medicine and Cellular Longevity, 2021 , 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Avdović2021b, title = {Synthesis and Biological Screening of New 4-Hydroxycoumarin Derivatives and Their Palladium(II) Complexes}, author = {E H Avdović and I P Petrović and M J Stevanović and L Saso and J M Dimitrić Marković and N D Filipović and M Ž Živić and T N Cvetić Antić and M V Žižić and N V Todorović and M Vukić and S R Trifunović and Z S Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105724813&doi=10.1155%2f2021%2f8849568&partnerID=40&md5=bf51ad49bd1a47ace950ddaa53b83d9b}, doi = {10.1155/2021/8849568}, year = {2021}, date = {2021-01-01}, journal = {Oxidative Medicine and Cellular Longevity}, volume = {2021}, abstract = {Two newly synthesized 4-hydroxycoumarin bidentate ligands (L1 and L2) and their palladium(II) complexes (C1 and C2) were screened for their biological activities, in vitro and in vivo. Structures of new compounds were established based on elemental analysis, 1H NMR, 13C NMR, and IR spectroscopic techniques. The obtained compounds were tested for their antioxidative and cytotoxic activities and results pointed to selective antiradical activity of palladium(II) complexes towards •OH and -•OOH radicals and anti-ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical) activity comparable to that of ascorbate. Results indicated the effect of C1 and C2 on the enzymatic activity of the antioxidative defense system. In vitro cytotoxicity assay performed on different carcinoma cell lines (HCT166, A375, and MIA PaCa-2), and one healthy fibroblast cell line (MRC-5) showed a cytotoxic effect of both C1 and C2, expressed as a decrease in carcinoma cells' viability, mostly by induction of apoptosis. In vivo toxicity tests performed on zebrafish embryos indicated different effects of C1 and C2, ranging from adverse developmental effect to no toxicity, depending on tested concentration. According to docking studies, both complexes (C1 and C2) showed better inhibitory activity in comparison to other palladium(II) complexes. © 2021 Edina H. Avdović et al.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two newly synthesized 4-hydroxycoumarin bidentate ligands (L1 and L2) and their palladium(II) complexes (C1 and C2) were screened for their biological activities, in vitro and in vivo. Structures of new compounds were established based on elemental analysis, 1H NMR, 13C NMR, and IR spectroscopic techniques. The obtained compounds were tested for their antioxidative and cytotoxic activities and results pointed to selective antiradical activity of palladium(II) complexes towards •OH and -•OOH radicals and anti-ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical) activity comparable to that of ascorbate. Results indicated the effect of C1 and C2 on the enzymatic activity of the antioxidative defense system. In vitro cytotoxicity assay performed on different carcinoma cell lines (HCT166, A375, and MIA PaCa-2), and one healthy fibroblast cell line (MRC-5) showed a cytotoxic effect of both C1 and C2, expressed as a decrease in carcinoma cells' viability, mostly by induction of apoptosis. In vivo toxicity tests performed on zebrafish embryos indicated different effects of C1 and C2, ranging from adverse developmental effect to no toxicity, depending on tested concentration. According to docking studies, both complexes (C1 and C2) showed better inhibitory activity in comparison to other palladium(II) complexes. © 2021 Edina H. Avdović et al. |
| 10. | Anićijević, V J; Lazarević-Pašti, T D; Vasić, V M; Anićijević, Vasić D D: An insight into the efficient dimethoate adsorption on graphene-based materials—a combined experimental and dft study. In: Applied Sciences (Switzerland), 11 (9), 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Anićijević2021, title = {An insight into the efficient dimethoate adsorption on graphene-based materials—a combined experimental and dft study}, author = {V J Anićijević and T D Lazarević-Pašti and V M Vasić and D D Vasić Anićijević}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105738526&doi=10.3390%2fapp11094014&partnerID=40&md5=154c216a07b40f0ea2e10c97747cd81b}, doi = {10.3390/app11094014}, year = {2021}, date = {2021-01-01}, journal = {Applied Sciences (Switzerland)}, volume = {11}, number = {9}, abstract = {(1) Background: The development of highly efficient methods for removing hazardous substances from the environment attracts increasing attention. Understanding the basic principles of the removal processes using graphene materials is equally essential to confirm their application efficiency and safety. (2) Methods: In this contribution, adsorption of pesticide dimethoate (DMT) on graphene-based materials has been investigated on the molecular level. (3) Results: The experimental results’ analysis revealed a cooperative binding mechanism of the DMT on the adsorption sites of investigated materials—graphene oxide (GO) and industrial graphene (IG). The adsorption data were analyzed using various adsorption isotherms to determine the thermodynamics of the adsorption process. The experimental results were correlated with Density Functional Theory (DFT) calculations of DMT adsorption on the model surfaces that appropriately describe the graphene materials’ reactive features. (4) Conclusions: Considering experimental results, calculated adsorption energies, optimized adsorption geometries, and electronic structure, it was proposed that the dispersive interactions determine the adsorption properties of DMT on plain graphene sites (physisorption). Additionally, it was shown that the existence of vacancy-type defect sites on the surfaces could induce strong and dissociative adsorption (chemisorption) of DMT. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {}, pubstate = {published}, tppubtype = {article} } (1) Background: The development of highly efficient methods for removing hazardous substances from the environment attracts increasing attention. Understanding the basic principles of the removal processes using graphene materials is equally essential to confirm their application efficiency and safety. (2) Methods: In this contribution, adsorption of pesticide dimethoate (DMT) on graphene-based materials has been investigated on the molecular level. (3) Results: The experimental results’ analysis revealed a cooperative binding mechanism of the DMT on the adsorption sites of investigated materials—graphene oxide (GO) and industrial graphene (IG). The adsorption data were analyzed using various adsorption isotherms to determine the thermodynamics of the adsorption process. The experimental results were correlated with Density Functional Theory (DFT) calculations of DMT adsorption on the model surfaces that appropriately describe the graphene materials’ reactive features. (4) Conclusions: Considering experimental results, calculated adsorption energies, optimized adsorption geometries, and electronic structure, it was proposed that the dispersive interactions determine the adsorption properties of DMT on plain graphene sites (physisorption). Additionally, it was shown that the existence of vacancy-type defect sites on the surfaces could induce strong and dissociative adsorption (chemisorption) of DMT. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. |
| 11. | Milanovic, Ž B; Markovic, Z S; Dimic, D S; Klisuric, O R; Radojevic, I D; Šeklic, D S; Živanovic, M N; Markovic, J D; Radulovic, M; Avdovic, E H: Synthesis, structural characterization, biological activity and molecular docking study of 4,7-dihydroxycoumarinmodified by aminophenol derivatives. In: Comptes Rendus Chimie, 24 (2), pp. 215-232, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Milanovic2021215, title = {Synthesis, structural characterization, biological activity and molecular docking study of 4,7-dihydroxycoumarinmodified by aminophenol derivatives}, author = {Ž B Milanovic and Z S Markovic and D S Dimic and O R Klisuric and I D Radojevic and D S Šeklic and M N Živanovic and J D Markovic and M Radulovic and E H Avdovic}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85106670229&doi=10.5802%2fCRCHIM.68&partnerID=40&md5=e3c6254991e41cecf95af23791142965}, doi = {10.5802/CRCHIM.68}, year = {2021}, date = {2021-01-01}, journal = {Comptes Rendus Chimie}, volume = {24}, number = {2}, pages = {215-232}, abstract = {In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2- hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds. © 2021 Elsevier Masson SAS. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2- hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds. © 2021 Elsevier Masson SAS. All rights reserved. |
| 12. | Ajdarić, J; Ibrić, S; Pavlović, A; Ignjatović, L; Ivković, B: Prediction of drug stability using deep learning approach: Case study of esomeprazole 40 mg freeze-dried powder for solution. In: Pharmaceutics, 13 (6), 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Ajdarić2021, title = {Prediction of drug stability using deep learning approach: Case study of esomeprazole 40 mg freeze-dried powder for solution}, author = {J Ajdarić and S Ibrić and A Pavlović and L Ignjatović and B Ivković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107948276&doi=10.3390%2fpharmaceutics13060829&partnerID=40&md5=73b24b30b5c3e93fb0082a0dea2965b0}, doi = {10.3390/pharmaceutics13060829}, year = {2021}, date = {2021-01-01}, journal = {Pharmaceutics}, volume = {13}, number = {6}, abstract = {A critical step in the production of Esomeprazole powder for solution is a period between the filling process and lyophilization, where all vials, partially closed, are completely exposed to environmental influences. Excessive instability reflects in pH value variations caused by oxygen’s impact. In order to provide pH control, which consequently affects drug stability, Esomeprazole batches, produced in the same way, were kept in partially closed vials for 3 h at temperatures of 20◦C and −30◦C, after which they were lyophilized and stored for long-term stability for 36 months. The aim of the presented study was to apply a deep-learning algorithm for the prediction of the Esomeprazole stability profile and to determine the pH limit for the reconstituted solution of the final freeze-dried product that would assure a quality product profile over a storage period of 36 months. Multilayer perceptron (MLP) as a deep learning tool, with four layers, was used. The pH value of Esomeprazole solution and time of storage (months) were inputs for the network, while Esomeprazole assay and four main impurities were outputs of the network. In order to keep all related substances and Esomeprazole assay in accordance with specifications for the whole shelf life, the pH value for the reconstituted finish product should be set in the range of 10.4–10.6. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A critical step in the production of Esomeprazole powder for solution is a period between the filling process and lyophilization, where all vials, partially closed, are completely exposed to environmental influences. Excessive instability reflects in pH value variations caused by oxygen’s impact. In order to provide pH control, which consequently affects drug stability, Esomeprazole batches, produced in the same way, were kept in partially closed vials for 3 h at temperatures of 20◦C and −30◦C, after which they were lyophilized and stored for long-term stability for 36 months. The aim of the presented study was to apply a deep-learning algorithm for the prediction of the Esomeprazole stability profile and to determine the pH limit for the reconstituted solution of the final freeze-dried product that would assure a quality product profile over a storage period of 36 months. Multilayer perceptron (MLP) as a deep learning tool, with four layers, was used. The pH value of Esomeprazole solution and time of storage (months) were inputs for the network, while Esomeprazole assay and four main impurities were outputs of the network. In order to keep all related substances and Esomeprazole assay in accordance with specifications for the whole shelf life, the pH value for the reconstituted finish product should be set in the range of 10.4–10.6. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. |
| 13. | Maksimović, Dragišić J; Mojović, M; Vučinić, Ž; Maksimović, V: Spatial distribution of apoplastic antioxidative constituents in maize root. In: Physiologia Plantarum, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{DragišićMaksimović2021, title = {Spatial distribution of apoplastic antioxidative constituents in maize root}, author = {J Dragišić Maksimović and M Mojović and Ž Vučinić and V Maksimović}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108365280&doi=10.1111%2fppl.13476&partnerID=40&md5=25d74508b1a75aa19bf65104d3635b34}, doi = {10.1111/ppl.13476}, year = {2021}, date = {2021-01-01}, journal = {Physiologia Plantarum}, abstract = {Apoplastic antioxidative constituents (enzymes, primary and secondary metabolites, ROS) from different root zones of hydroponically grown maize (Zea mays L.) were investigated using a noninvasive isolation procedure: filter strip method. Filter strips were placed at specific positions on the root surface: apical zone (tip) and basal zone (base) to absorb apoplastic fluid. Three major classes of low-weight metabolites (organic acids, sugars, and phenolics) have been identified by HPLC-ECD. The longitudinal distribution of sugars and organic acids had the same pattern: higher concentration in the tip than the base, while it was vice versa for phenolics. The specific activities of guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase were higher in the apoplastic fluid from the root base than the tip, and their different isoforms were separated by isoelectric focusing. Electron paramagnetic resonance (EPR) spectroscopy coupled with the spin-trapping method using DEPMPO showed a persistent generation of hydroxyl radical in the root tip. In vivo EPR imaging of the whole maize root with membrane-permeable and impermeable aminoxyl spin-probes, enabling real-time detection of ROS formation within and outside the membranes, demonstrated ROS accumulation on the root surface, while endodermis and central cylinder were ROS free. For the first time in plant research, 2D EPR images enabled the direct demonstration of site-specific free radical production along the root. Highly sensitive analytical techniques combined with the filter strips, as a non-invasive tool, have increased our knowledge of metabolic processes occurring in the apoplast and their spatial–temporal changes in small regions of the intact root tissue. © 2021 Scandinavian Plant Physiology Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Apoplastic antioxidative constituents (enzymes, primary and secondary metabolites, ROS) from different root zones of hydroponically grown maize (Zea mays L.) were investigated using a noninvasive isolation procedure: filter strip method. Filter strips were placed at specific positions on the root surface: apical zone (tip) and basal zone (base) to absorb apoplastic fluid. Three major classes of low-weight metabolites (organic acids, sugars, and phenolics) have been identified by HPLC-ECD. The longitudinal distribution of sugars and organic acids had the same pattern: higher concentration in the tip than the base, while it was vice versa for phenolics. The specific activities of guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase were higher in the apoplastic fluid from the root base than the tip, and their different isoforms were separated by isoelectric focusing. Electron paramagnetic resonance (EPR) spectroscopy coupled with the spin-trapping method using DEPMPO showed a persistent generation of hydroxyl radical in the root tip. In vivo EPR imaging of the whole maize root with membrane-permeable and impermeable aminoxyl spin-probes, enabling real-time detection of ROS formation within and outside the membranes, demonstrated ROS accumulation on the root surface, while endodermis and central cylinder were ROS free. For the first time in plant research, 2D EPR images enabled the direct demonstration of site-specific free radical production along the root. Highly sensitive analytical techniques combined with the filter strips, as a non-invasive tool, have increased our knowledge of metabolic processes occurring in the apoplast and their spatial–temporal changes in small regions of the intact root tissue. © 2021 Scandinavian Plant Physiology Society |
| 14. | Petrović, S; Stanković, M; Pavlović, S; Mojović, Z; Radić, N; Mojović, M; Rožić, L: Nickel oxide on mechanochemically synthesized TiO2–CeO2: photocatalytic and electrochemical activity. In: Reaction Kinetics, Mechanisms and Catalysis, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Petrović2021, title = {Nickel oxide on mechanochemically synthesized TiO2–CeO2: photocatalytic and electrochemical activity}, author = {S Petrović and M Stanković and S Pavlović and Z Mojović and N Radić and M Mojović and L Rožić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108609286&doi=10.1007%2fs11144-021-02014-8&partnerID=40&md5=77b077247e58e48489f41b8a9f6b6b14}, doi = {10.1007/s11144-021-02014-8}, year = {2021}, date = {2021-01-01}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, abstract = {This paper presents a new two-step method for the synthesis of NiO/TiO2–CeO2 semiconductors, which implies, the first, the mechanochemical synthesis of TiO2–CeO2 support, and the second is the doping of different NiO contents by chemical precipitation in an aqueous medium in an ambient atmosphere. Structural, optical, electrochemical and photocatalytic properties of NiO/TiO2–CeO2 semiconductors were examined. The influence of different NiO contents on the electrocatalytic activity of NiO/TiO2–CeO2 samples was investigated in the oxygen evolution reaction and the results showed that the samples with the lowest NiO content have the highest electroactivity. The photocatalytic activity was determined during the phenol decomposition process over the samples with different NiO:TiO2–CeO2 ratios and the best photocatalytic activity is observed for the sample with 4.1 mol% NiO. The sample with the lowest NiO content obtained by a relatively simple method is suitable for use both as an electrode material in the oxygen evolution reaction and as a photocatalyst in the phenol decomposition process. © 2021, Akadémiai Kiadó, Budapest, Hungary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a new two-step method for the synthesis of NiO/TiO2–CeO2 semiconductors, which implies, the first, the mechanochemical synthesis of TiO2–CeO2 support, and the second is the doping of different NiO contents by chemical precipitation in an aqueous medium in an ambient atmosphere. Structural, optical, electrochemical and photocatalytic properties of NiO/TiO2–CeO2 semiconductors were examined. The influence of different NiO contents on the electrocatalytic activity of NiO/TiO2–CeO2 samples was investigated in the oxygen evolution reaction and the results showed that the samples with the lowest NiO content have the highest electroactivity. The photocatalytic activity was determined during the phenol decomposition process over the samples with different NiO:TiO2–CeO2 ratios and the best photocatalytic activity is observed for the sample with 4.1 mol% NiO. The sample with the lowest NiO content obtained by a relatively simple method is suitable for use both as an electrode material in the oxygen evolution reaction and as a photocatalyst in the phenol decomposition process. © 2021, Akadémiai Kiadó, Budapest, Hungary. |
| 15. | Stanojević, A; Milovanović, B; Stanković, I; Etinski, M; Petković, M: The significance of the metal cation in guanine-quartet - metalloporphyrin complexes. In: Physical chemistry chemical physics : PCCP, 23 (1), pp. 574-584, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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. |
| 16. | Milanović, Z B; Antonijević, M R; Amić, A D; Avdović, E H; Dimić, D S; Milenković, D A; Marković, Z S: Inhibitory activity of quercetin, its metabolite, and standard antiviral drugs towards enzymes essential for SARS-CoV-2: The role of acid-base equilibria. In: RSC Advances, 11 (5), pp. 2838-2847, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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. |
| 17. | 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?. In: Journal of Power Sources, 482 , 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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. |
| 18. | Milovanović, B; Novak, J; Etinski, M; Domcke, W; Došlić, N: Simulation of UV absorption spectra and relaxation dynamics of uracil and uracil-water clusters. In: Physical Chemistry Chemical Physics, 23 (4), pp. 2594-2604, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Milovanović20212594, title = {Simulation of UV absorption spectra and relaxation dynamics of uracil and uracil-water clusters}, author = {B Milovanović and J Novak and M Etinski and W Domcke and N Došlić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100585833&doi=10.1039%2fd0cp05618a&partnerID=40&md5=0704372fccfa73cb7a1d8d977e0681aa}, doi = {10.1039/d0cp05618a}, year = {2021}, date = {2021-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {23}, number = {4}, pages = {2594-2604}, abstract = {Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy with nonadiabatic dynamics simulations to identify the photophysical mechanisms that can give rise to experimentally observed decay time constants. We first compute and theoretically assign the electronic spectra of uracil using the second-order algebraic-diagrammatic-construction (ADC(2)) method. The obtained electronic states, their energy differences and state-specific solvation effects are the prerequisites for understanding the photodynamics. We then use nonadiabatic trajectory-surface-hopping dynamics simulations to investigate the photoinduced dynamics of uracil and uracil-water clusters. In contrast to previous studies, we found that a single mechanism - the ethylenic twist around the C=C bond - is responsible for the ultrafast component of the nonradiative decay, both in the gas phase and in solution. Very good agreement with the experimentally determined ultrashort decay time constants is obtained. © the Owner Societies 2021.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy with nonadiabatic dynamics simulations to identify the photophysical mechanisms that can give rise to experimentally observed decay time constants. We first compute and theoretically assign the electronic spectra of uracil using the second-order algebraic-diagrammatic-construction (ADC(2)) method. The obtained electronic states, their energy differences and state-specific solvation effects are the prerequisites for understanding the photodynamics. We then use nonadiabatic trajectory-surface-hopping dynamics simulations to investigate the photoinduced dynamics of uracil and uracil-water clusters. In contrast to previous studies, we found that a single mechanism - the ethylenic twist around the C=C bond - is responsible for the ultrafast component of the nonradiative decay, both in the gas phase and in solution. Very good agreement with the experimentally determined ultrashort decay time constants is obtained. © the Owner Societies 2021. |
| 19. | Popa, A; Borcanescu, S; Holclajtner-Antunović, I; Bajuk-Bogdanović, D; Uskoković-Marković, S: Preparation and characterisation of amino-functionalized pore-expanded mesoporous silica for carbon dioxide capture. In: Journal of Porous Materials, 28 (1), pp. 143-156, 2021. (Type: Journal Article | Abstract | Links | BibTeX) @article{Popa2021143, title = {Preparation and characterisation of amino-functionalized pore-expanded mesoporous silica for carbon dioxide capture}, author = {A Popa and S Borcanescu and I Holclajtner-Antunović and D Bajuk-Bogdanović and S Uskoković-Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090145787&doi=10.1007%2fs10934-020-00974-1&partnerID=40&md5=54b7bd1da07271c501d744cc45d6da6d}, doi = {10.1007/s10934-020-00974-1}, year = {2021}, date = {2021-01-01}, journal = {Journal of Porous Materials}, volume = {28}, number = {1}, pages = {143-156}, abstract = {In this study, the preparation of some large-pore ordered mesoporous silicas using a proper surfactant with different swelling agents was carried out. The synthesis of conventional SBA-15 was modified to obtain pore-expanded materials, with pore diameters up to 10 nm. To use a micelle swelling agent with a moderate swelling ability, three swelling agents were selected: 1-phenyl-decane (Dec), butyl benzene (BB), and mesitylene (Mes). These syntheses aimed to achieve a pore diameter enlargement but at the same time to avoid the formation of heterogeneous and/or poorly defined nanostructure of silica. The CO2 adsorbents were obtained by post-synthesis functionalization treatments carried out by grafting with 3-aminopropyl triethoxysilane. The CO2 adsorption/desorption experiments showed that carbon dioxide sorption capacities depend on the textural characteristics and the temperature used for the adsorption process. Good CO2 adsorption capacities were obtained for all prepared adsorbents, especially for SSBA-15-Mes-sil and SSBA-15-BB-sil samples. At 50 °C, the SSBA-15-Mes-sil sample has an adsorption capacity of 3.58 mmol CO2/g SiO2, and an efficiency of amino groups of 0.99 mmol CO2/mmol NH2. The results of adsorption capacities are comparable or even superior with the ones reported in literature for mesoporous silica functionalized with different amines. After nine adsorption–desorption cycles, the performance of the SSBA-15-Mes-sil adsorbent is relatively stable, with a low decrease in the adsorption capacity (0.1 mmol/g of CO2, i.e., 2.8% of initial capacity). These studies show the potential of mesoporous silica for carbon dioxide capture. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, the preparation of some large-pore ordered mesoporous silicas using a proper surfactant with different swelling agents was carried out. The synthesis of conventional SBA-15 was modified to obtain pore-expanded materials, with pore diameters up to 10 nm. To use a micelle swelling agent with a moderate swelling ability, three swelling agents were selected: 1-phenyl-decane (Dec), butyl benzene (BB), and mesitylene (Mes). These syntheses aimed to achieve a pore diameter enlargement but at the same time to avoid the formation of heterogeneous and/or poorly defined nanostructure of silica. The CO2 adsorbents were obtained by post-synthesis functionalization treatments carried out by grafting with 3-aminopropyl triethoxysilane. The CO2 adsorption/desorption experiments showed that carbon dioxide sorption capacities depend on the textural characteristics and the temperature used for the adsorption process. Good CO2 adsorption capacities were obtained for all prepared adsorbents, especially for SSBA-15-Mes-sil and SSBA-15-BB-sil samples. At 50 °C, the SSBA-15-Mes-sil sample has an adsorption capacity of 3.58 mmol CO2/g SiO2, and an efficiency of amino groups of 0.99 mmol CO2/mmol NH2. The results of adsorption capacities are comparable or even superior with the ones reported in literature for mesoporous silica functionalized with different amines. After nine adsorption–desorption cycles, the performance of the SSBA-15-Mes-sil adsorbent is relatively stable, with a low decrease in the adsorption capacity (0.1 mmol/g of CO2, i.e., 2.8% of initial capacity). These studies show the potential of mesoporous silica for carbon dioxide capture. © 2020, Springer Science+Business Media, LLC, part of Springer Nature. |
| 20. | 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. In: Optics and Laser Technology, 134 , 2021. (Type: Journal Article | Abstract | Links | BibTeX) @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 |
2021 |
Pašti, I A; Mentus, S V “Spot the difference”—just a game or the game-changer? Journal Article Joule, 5 (3), pp. 519-521, 2021. @article{Pašti2021519, title = {“Spot the difference”—just a game or the game-changer?}, author = {I A Pašti and S V Mentus}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102377113&doi=10.1016%2fj.joule.2021.02.017&partnerID=40&md5=df34ce06e7a1179b8a047a94c1e65a66}, doi = {10.1016/j.joule.2021.02.017}, year = {2021}, date = {2021-01-01}, journal = {Joule}, volume = {5}, number = {3}, pages = {519-521}, abstract = {Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. Recently in iScience, Hodnik et al. provide compelling evidence that the standard top-down investigation of electrocatalyst stability fails to provide the fundamental understanding of nanoparticle structure-stability relationships. Instead, the authors provide a new bottom-up strategy, allowing researchers to study the structural evolution of individual nanoparticles and a deep link to their structure-stability properties. © 2021 Elsevier Inc. |
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 |
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 |
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. |
Ignjatović, S; Blawert, C; Serdechnova, M; Karpushenkov, S; Damjanović, M; Karlova, P; Dovzhenko, G; Wieland, D C F; Zeller-Plumhoff, B; Starykevich, M; Stojanović, S; Damjanović-Vasilić, L; Zheludkevich, M L Advanced Engineering Materials, 2021. @article{Ignjatović2021b, title = {The Influence of In Situ Anatase Particle Addition on the Formation and Properties of Multifunctional Plasma Electrolytic Oxidation Coatings on AA2024 Aluminum Alloy}, author = {S Ignjatović and C Blawert and M Serdechnova and S Karpushenkov and M Damjanović and P Karlova and G Dovzhenko and D C F Wieland and B Zeller-Plumhoff and M Starykevich and S Stojanović and L Damjanović-Vasilić and M L Zheludkevich}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103078141&doi=10.1002%2fadem.202001527&partnerID=40&md5=f0908c6cbfc49b742c83fddd4d92daa5}, doi = {10.1002/adem.202001527}, year = {2021}, date = {2021-01-01}, journal = {Advanced Engineering Materials}, abstract = {Plasma electrolytic oxidation (PEO) with in situ anatase particle addition is applied to functionalize the surface of AA2024 alloy. A base potassium titanium oxide oxalate dihydrate aqueous electrolyte is used with up to 30 g L−1 anatase particle addition. The coatings’ morphology and phase composition as a function of the anatase concentration in the electrolyte are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES). Photocatalytic activity, stability in chloride solution, and tribological properties are also determined. The main coating forming phases are anatase and rutile on top of a mixed interface region consisting of TiAl2O5 as reaction product between the TiO2 and an Al2O3 barrier layer on top of the Al substrate. The mixed layer is extending with increasing amount of particles added, due to intensified discharges. In addition, anatase-to-rutile phase ratio increases due to the additional anatase particles in the electrolyte. Thus, the photocatalytic activity is improving with the particle addition. The coatings’ mechanical resistance is dropping first before increasing again with more particles added. Chemical and restored mechanical stability seems to be related to the extended mixed interface formation, which strengthens the bond to the substrate when more particles are added. © 2021 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plasma electrolytic oxidation (PEO) with in situ anatase particle addition is applied to functionalize the surface of AA2024 alloy. A base potassium titanium oxide oxalate dihydrate aqueous electrolyte is used with up to 30 g L−1 anatase particle addition. The coatings’ morphology and phase composition as a function of the anatase concentration in the electrolyte are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES). Photocatalytic activity, stability in chloride solution, and tribological properties are also determined. The main coating forming phases are anatase and rutile on top of a mixed interface region consisting of TiAl2O5 as reaction product between the TiO2 and an Al2O3 barrier layer on top of the Al substrate. The mixed layer is extending with increasing amount of particles added, due to intensified discharges. In addition, anatase-to-rutile phase ratio increases due to the additional anatase particles in the electrolyte. Thus, the photocatalytic activity is improving with the particle addition. The coatings’ mechanical resistance is dropping first before increasing again with more particles added. Chemical and restored mechanical stability seems to be related to the extended mixed interface formation, which strengthens the bond to the substrate when more particles are added. © 2021 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH |
Vasić, M M; Žák, T; Minić, D M Journal of Thermal Analysis and Calorimetry, 2021. @article{Vasić2021, title = {Kinetics and influence of thermally induced crystallization of Fe,Ni-containing phases on thermomagnetic properties of Fe40Ni40B12Si8 amorphous alloy}, author = {M M Vasić and T Žák and D M Minić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104519208&doi=10.1007%2fs10973-021-10819-x&partnerID=40&md5=3b45d292fcdc3c963d41874830a1af9a}, doi = {10.1007/s10973-021-10819-x}, year = {2021}, date = {2021-01-01}, journal = {Journal of Thermal Analysis and Calorimetry}, abstract = {Thermal treatment of Fe40Ni40B12Si8 amorphous alloy leads to crystallization of various Fe and Ni-containing phases and their recrystallization, affecting the functional properties of the alloy. Kinetics of multistep crystallization of Fe40Ni40B12Si8 amorphous alloy and influence of thermally induced microstructural transformations on magnetic moment of the alloy were studied by means of structural examination, thermal analysis and thermomagnetic measurements. Temperature regions of growth and loss of magnetic moment of the alloy were correlated with the microstructural changes. Curie temperatures of the alloy in fully amorphous and fully crystallized form were observed at 620 and 910 K, respectively. Detailed kinetic study including deconvolution of the complex exothermic DTA peaks yielded Arrhenius parameters and kinetic model of individual crystallization steps, which reflect the nature of the studied processes and the alloy chemical composition. The obtained parameters and kinetic models can be used for kinetic predictions of thermal stability and functionality of the alloy. © 2021, Akadémiai Kiadó, Budapest, Hungary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thermal treatment of Fe40Ni40B12Si8 amorphous alloy leads to crystallization of various Fe and Ni-containing phases and their recrystallization, affecting the functional properties of the alloy. Kinetics of multistep crystallization of Fe40Ni40B12Si8 amorphous alloy and influence of thermally induced microstructural transformations on magnetic moment of the alloy were studied by means of structural examination, thermal analysis and thermomagnetic measurements. Temperature regions of growth and loss of magnetic moment of the alloy were correlated with the microstructural changes. Curie temperatures of the alloy in fully amorphous and fully crystallized form were observed at 620 and 910 K, respectively. Detailed kinetic study including deconvolution of the complex exothermic DTA peaks yielded Arrhenius parameters and kinetic model of individual crystallization steps, which reflect the nature of the studied processes and the alloy chemical composition. The obtained parameters and kinetic models can be used for kinetic predictions of thermal stability and functionality of the alloy. © 2021, Akadémiai Kiadó, Budapest, Hungary. |
Avdović, E H; Petrović, I P; Stevanović, M J; Saso, L; Marković, Dimitrić J M; Filipović, N D; Živić, M Ž; Antić, Cvetić T N; Žižić, M V; Todorović, N V; Vukić, M; Trifunović, S R; Marković, Z S Synthesis and Biological Screening of New 4-Hydroxycoumarin Derivatives and Their Palladium(II) Complexes Journal Article Oxidative Medicine and Cellular Longevity, 2021 , 2021. @article{Avdović2021b, title = {Synthesis and Biological Screening of New 4-Hydroxycoumarin Derivatives and Their Palladium(II) Complexes}, author = {E H Avdović and I P Petrović and M J Stevanović and L Saso and J M Dimitrić Marković and N D Filipović and M Ž Živić and T N Cvetić Antić and M V Žižić and N V Todorović and M Vukić and S R Trifunović and Z S Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105724813&doi=10.1155%2f2021%2f8849568&partnerID=40&md5=bf51ad49bd1a47ace950ddaa53b83d9b}, doi = {10.1155/2021/8849568}, year = {2021}, date = {2021-01-01}, journal = {Oxidative Medicine and Cellular Longevity}, volume = {2021}, abstract = {Two newly synthesized 4-hydroxycoumarin bidentate ligands (L1 and L2) and their palladium(II) complexes (C1 and C2) were screened for their biological activities, in vitro and in vivo. Structures of new compounds were established based on elemental analysis, 1H NMR, 13C NMR, and IR spectroscopic techniques. The obtained compounds were tested for their antioxidative and cytotoxic activities and results pointed to selective antiradical activity of palladium(II) complexes towards •OH and -•OOH radicals and anti-ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical) activity comparable to that of ascorbate. Results indicated the effect of C1 and C2 on the enzymatic activity of the antioxidative defense system. In vitro cytotoxicity assay performed on different carcinoma cell lines (HCT166, A375, and MIA PaCa-2), and one healthy fibroblast cell line (MRC-5) showed a cytotoxic effect of both C1 and C2, expressed as a decrease in carcinoma cells' viability, mostly by induction of apoptosis. In vivo toxicity tests performed on zebrafish embryos indicated different effects of C1 and C2, ranging from adverse developmental effect to no toxicity, depending on tested concentration. According to docking studies, both complexes (C1 and C2) showed better inhibitory activity in comparison to other palladium(II) complexes. © 2021 Edina H. Avdović et al.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two newly synthesized 4-hydroxycoumarin bidentate ligands (L1 and L2) and their palladium(II) complexes (C1 and C2) were screened for their biological activities, in vitro and in vivo. Structures of new compounds were established based on elemental analysis, 1H NMR, 13C NMR, and IR spectroscopic techniques. The obtained compounds were tested for their antioxidative and cytotoxic activities and results pointed to selective antiradical activity of palladium(II) complexes towards •OH and -•OOH radicals and anti-ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical) activity comparable to that of ascorbate. Results indicated the effect of C1 and C2 on the enzymatic activity of the antioxidative defense system. In vitro cytotoxicity assay performed on different carcinoma cell lines (HCT166, A375, and MIA PaCa-2), and one healthy fibroblast cell line (MRC-5) showed a cytotoxic effect of both C1 and C2, expressed as a decrease in carcinoma cells' viability, mostly by induction of apoptosis. In vivo toxicity tests performed on zebrafish embryos indicated different effects of C1 and C2, ranging from adverse developmental effect to no toxicity, depending on tested concentration. According to docking studies, both complexes (C1 and C2) showed better inhibitory activity in comparison to other palladium(II) complexes. © 2021 Edina H. Avdović et al. |
Anićijević, V J; Lazarević-Pašti, T D; Vasić, V M; Anićijević, Vasić D D An insight into the efficient dimethoate adsorption on graphene-based materials—a combined experimental and dft study Journal Article Applied Sciences (Switzerland), 11 (9), 2021. @article{Anićijević2021, title = {An insight into the efficient dimethoate adsorption on graphene-based materials—a combined experimental and dft study}, author = {V J Anićijević and T D Lazarević-Pašti and V M Vasić and D D Vasić Anićijević}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105738526&doi=10.3390%2fapp11094014&partnerID=40&md5=154c216a07b40f0ea2e10c97747cd81b}, doi = {10.3390/app11094014}, year = {2021}, date = {2021-01-01}, journal = {Applied Sciences (Switzerland)}, volume = {11}, number = {9}, abstract = {(1) Background: The development of highly efficient methods for removing hazardous substances from the environment attracts increasing attention. Understanding the basic principles of the removal processes using graphene materials is equally essential to confirm their application efficiency and safety. (2) Methods: In this contribution, adsorption of pesticide dimethoate (DMT) on graphene-based materials has been investigated on the molecular level. (3) Results: The experimental results’ analysis revealed a cooperative binding mechanism of the DMT on the adsorption sites of investigated materials—graphene oxide (GO) and industrial graphene (IG). The adsorption data were analyzed using various adsorption isotherms to determine the thermodynamics of the adsorption process. The experimental results were correlated with Density Functional Theory (DFT) calculations of DMT adsorption on the model surfaces that appropriately describe the graphene materials’ reactive features. (4) Conclusions: Considering experimental results, calculated adsorption energies, optimized adsorption geometries, and electronic structure, it was proposed that the dispersive interactions determine the adsorption properties of DMT on plain graphene sites (physisorption). Additionally, it was shown that the existence of vacancy-type defect sites on the surfaces could induce strong and dissociative adsorption (chemisorption) of DMT. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {}, pubstate = {published}, tppubtype = {article} } (1) Background: The development of highly efficient methods for removing hazardous substances from the environment attracts increasing attention. Understanding the basic principles of the removal processes using graphene materials is equally essential to confirm their application efficiency and safety. (2) Methods: In this contribution, adsorption of pesticide dimethoate (DMT) on graphene-based materials has been investigated on the molecular level. (3) Results: The experimental results’ analysis revealed a cooperative binding mechanism of the DMT on the adsorption sites of investigated materials—graphene oxide (GO) and industrial graphene (IG). The adsorption data were analyzed using various adsorption isotherms to determine the thermodynamics of the adsorption process. The experimental results were correlated with Density Functional Theory (DFT) calculations of DMT adsorption on the model surfaces that appropriately describe the graphene materials’ reactive features. (4) Conclusions: Considering experimental results, calculated adsorption energies, optimized adsorption geometries, and electronic structure, it was proposed that the dispersive interactions determine the adsorption properties of DMT on plain graphene sites (physisorption). Additionally, it was shown that the existence of vacancy-type defect sites on the surfaces could induce strong and dissociative adsorption (chemisorption) of DMT. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. |
Milanovic, Ž B; Markovic, Z S; Dimic, D S; Klisuric, O R; Radojevic, I D; Šeklic, D S; Živanovic, M N; Markovic, J D; Radulovic, M; Avdovic, E H Comptes Rendus Chimie, 24 (2), pp. 215-232, 2021. @article{Milanovic2021215, title = {Synthesis, structural characterization, biological activity and molecular docking study of 4,7-dihydroxycoumarinmodified by aminophenol derivatives}, author = {Ž B Milanovic and Z S Markovic and D S Dimic and O R Klisuric and I D Radojevic and D S Šeklic and M N Živanovic and J D Markovic and M Radulovic and E H Avdovic}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85106670229&doi=10.5802%2fCRCHIM.68&partnerID=40&md5=e3c6254991e41cecf95af23791142965}, doi = {10.5802/CRCHIM.68}, year = {2021}, date = {2021-01-01}, journal = {Comptes Rendus Chimie}, volume = {24}, number = {2}, pages = {215-232}, abstract = {In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2- hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds. © 2021 Elsevier Masson SAS. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2- hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds. © 2021 Elsevier Masson SAS. All rights reserved. |
Ajdarić, J; Ibrić, S; Pavlović, A; Ignjatović, L; Ivković, B Prediction of drug stability using deep learning approach: Case study of esomeprazole 40 mg freeze-dried powder for solution Journal Article Pharmaceutics, 13 (6), 2021. @article{Ajdarić2021, title = {Prediction of drug stability using deep learning approach: Case study of esomeprazole 40 mg freeze-dried powder for solution}, author = {J Ajdarić and S Ibrić and A Pavlović and L Ignjatović and B Ivković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107948276&doi=10.3390%2fpharmaceutics13060829&partnerID=40&md5=73b24b30b5c3e93fb0082a0dea2965b0}, doi = {10.3390/pharmaceutics13060829}, year = {2021}, date = {2021-01-01}, journal = {Pharmaceutics}, volume = {13}, number = {6}, abstract = {A critical step in the production of Esomeprazole powder for solution is a period between the filling process and lyophilization, where all vials, partially closed, are completely exposed to environmental influences. Excessive instability reflects in pH value variations caused by oxygen’s impact. In order to provide pH control, which consequently affects drug stability, Esomeprazole batches, produced in the same way, were kept in partially closed vials for 3 h at temperatures of 20◦C and −30◦C, after which they were lyophilized and stored for long-term stability for 36 months. The aim of the presented study was to apply a deep-learning algorithm for the prediction of the Esomeprazole stability profile and to determine the pH limit for the reconstituted solution of the final freeze-dried product that would assure a quality product profile over a storage period of 36 months. Multilayer perceptron (MLP) as a deep learning tool, with four layers, was used. The pH value of Esomeprazole solution and time of storage (months) were inputs for the network, while Esomeprazole assay and four main impurities were outputs of the network. In order to keep all related substances and Esomeprazole assay in accordance with specifications for the whole shelf life, the pH value for the reconstituted finish product should be set in the range of 10.4–10.6. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A critical step in the production of Esomeprazole powder for solution is a period between the filling process and lyophilization, where all vials, partially closed, are completely exposed to environmental influences. Excessive instability reflects in pH value variations caused by oxygen’s impact. In order to provide pH control, which consequently affects drug stability, Esomeprazole batches, produced in the same way, were kept in partially closed vials for 3 h at temperatures of 20◦C and −30◦C, after which they were lyophilized and stored for long-term stability for 36 months. The aim of the presented study was to apply a deep-learning algorithm for the prediction of the Esomeprazole stability profile and to determine the pH limit for the reconstituted solution of the final freeze-dried product that would assure a quality product profile over a storage period of 36 months. Multilayer perceptron (MLP) as a deep learning tool, with four layers, was used. The pH value of Esomeprazole solution and time of storage (months) were inputs for the network, while Esomeprazole assay and four main impurities were outputs of the network. In order to keep all related substances and Esomeprazole assay in accordance with specifications for the whole shelf life, the pH value for the reconstituted finish product should be set in the range of 10.4–10.6. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. |
Maksimović, Dragišić J; Mojović, M; Vučinić, Ž; Maksimović, V Spatial distribution of apoplastic antioxidative constituents in maize root Journal Article Physiologia Plantarum, 2021. @article{DragišićMaksimović2021, title = {Spatial distribution of apoplastic antioxidative constituents in maize root}, author = {J Dragišić Maksimović and M Mojović and Ž Vučinić and V Maksimović}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108365280&doi=10.1111%2fppl.13476&partnerID=40&md5=25d74508b1a75aa19bf65104d3635b34}, doi = {10.1111/ppl.13476}, year = {2021}, date = {2021-01-01}, journal = {Physiologia Plantarum}, abstract = {Apoplastic antioxidative constituents (enzymes, primary and secondary metabolites, ROS) from different root zones of hydroponically grown maize (Zea mays L.) were investigated using a noninvasive isolation procedure: filter strip method. Filter strips were placed at specific positions on the root surface: apical zone (tip) and basal zone (base) to absorb apoplastic fluid. Three major classes of low-weight metabolites (organic acids, sugars, and phenolics) have been identified by HPLC-ECD. The longitudinal distribution of sugars and organic acids had the same pattern: higher concentration in the tip than the base, while it was vice versa for phenolics. The specific activities of guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase were higher in the apoplastic fluid from the root base than the tip, and their different isoforms were separated by isoelectric focusing. Electron paramagnetic resonance (EPR) spectroscopy coupled with the spin-trapping method using DEPMPO showed a persistent generation of hydroxyl radical in the root tip. In vivo EPR imaging of the whole maize root with membrane-permeable and impermeable aminoxyl spin-probes, enabling real-time detection of ROS formation within and outside the membranes, demonstrated ROS accumulation on the root surface, while endodermis and central cylinder were ROS free. For the first time in plant research, 2D EPR images enabled the direct demonstration of site-specific free radical production along the root. Highly sensitive analytical techniques combined with the filter strips, as a non-invasive tool, have increased our knowledge of metabolic processes occurring in the apoplast and their spatial–temporal changes in small regions of the intact root tissue. © 2021 Scandinavian Plant Physiology Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Apoplastic antioxidative constituents (enzymes, primary and secondary metabolites, ROS) from different root zones of hydroponically grown maize (Zea mays L.) were investigated using a noninvasive isolation procedure: filter strip method. Filter strips were placed at specific positions on the root surface: apical zone (tip) and basal zone (base) to absorb apoplastic fluid. Three major classes of low-weight metabolites (organic acids, sugars, and phenolics) have been identified by HPLC-ECD. The longitudinal distribution of sugars and organic acids had the same pattern: higher concentration in the tip than the base, while it was vice versa for phenolics. The specific activities of guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase were higher in the apoplastic fluid from the root base than the tip, and their different isoforms were separated by isoelectric focusing. Electron paramagnetic resonance (EPR) spectroscopy coupled with the spin-trapping method using DEPMPO showed a persistent generation of hydroxyl radical in the root tip. In vivo EPR imaging of the whole maize root with membrane-permeable and impermeable aminoxyl spin-probes, enabling real-time detection of ROS formation within and outside the membranes, demonstrated ROS accumulation on the root surface, while endodermis and central cylinder were ROS free. For the first time in plant research, 2D EPR images enabled the direct demonstration of site-specific free radical production along the root. Highly sensitive analytical techniques combined with the filter strips, as a non-invasive tool, have increased our knowledge of metabolic processes occurring in the apoplast and their spatial–temporal changes in small regions of the intact root tissue. © 2021 Scandinavian Plant Physiology Society |
Petrović, S; Stanković, M; Pavlović, S; Mojović, Z; Radić, N; Mojović, M; Rožić, L Nickel oxide on mechanochemically synthesized TiO2–CeO2: photocatalytic and electrochemical activity Journal Article Reaction Kinetics, Mechanisms and Catalysis, 2021. @article{Petrović2021, title = {Nickel oxide on mechanochemically synthesized TiO2–CeO2: photocatalytic and electrochemical activity}, author = {S Petrović and M Stanković and S Pavlović and Z Mojović and N Radić and M Mojović and L Rožić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108609286&doi=10.1007%2fs11144-021-02014-8&partnerID=40&md5=77b077247e58e48489f41b8a9f6b6b14}, doi = {10.1007/s11144-021-02014-8}, year = {2021}, date = {2021-01-01}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, abstract = {This paper presents a new two-step method for the synthesis of NiO/TiO2–CeO2 semiconductors, which implies, the first, the mechanochemical synthesis of TiO2–CeO2 support, and the second is the doping of different NiO contents by chemical precipitation in an aqueous medium in an ambient atmosphere. Structural, optical, electrochemical and photocatalytic properties of NiO/TiO2–CeO2 semiconductors were examined. The influence of different NiO contents on the electrocatalytic activity of NiO/TiO2–CeO2 samples was investigated in the oxygen evolution reaction and the results showed that the samples with the lowest NiO content have the highest electroactivity. The photocatalytic activity was determined during the phenol decomposition process over the samples with different NiO:TiO2–CeO2 ratios and the best photocatalytic activity is observed for the sample with 4.1 mol% NiO. The sample with the lowest NiO content obtained by a relatively simple method is suitable for use both as an electrode material in the oxygen evolution reaction and as a photocatalyst in the phenol decomposition process. © 2021, Akadémiai Kiadó, Budapest, Hungary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a new two-step method for the synthesis of NiO/TiO2–CeO2 semiconductors, which implies, the first, the mechanochemical synthesis of TiO2–CeO2 support, and the second is the doping of different NiO contents by chemical precipitation in an aqueous medium in an ambient atmosphere. Structural, optical, electrochemical and photocatalytic properties of NiO/TiO2–CeO2 semiconductors were examined. The influence of different NiO contents on the electrocatalytic activity of NiO/TiO2–CeO2 samples was investigated in the oxygen evolution reaction and the results showed that the samples with the lowest NiO content have the highest electroactivity. The photocatalytic activity was determined during the phenol decomposition process over the samples with different NiO:TiO2–CeO2 ratios and the best photocatalytic activity is observed for the sample with 4.1 mol% NiO. The sample with the lowest NiO content obtained by a relatively simple method is suitable for use both as an electrode material in the oxygen evolution reaction and as a photocatalyst in the phenol decomposition process. © 2021, Akadémiai Kiadó, Budapest, Hungary. |
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. |
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. |
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. |
Milovanović, B; Novak, J; Etinski, M; Domcke, W; Došlić, N Simulation of UV absorption spectra and relaxation dynamics of uracil and uracil-water clusters Journal Article Physical Chemistry Chemical Physics, 23 (4), pp. 2594-2604, 2021. @article{Milovanović20212594, title = {Simulation of UV absorption spectra and relaxation dynamics of uracil and uracil-water clusters}, author = {B Milovanović and J Novak and M Etinski and W Domcke and N Došlić}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100585833&doi=10.1039%2fd0cp05618a&partnerID=40&md5=0704372fccfa73cb7a1d8d977e0681aa}, doi = {10.1039/d0cp05618a}, year = {2021}, date = {2021-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {23}, number = {4}, pages = {2594-2604}, abstract = {Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy with nonadiabatic dynamics simulations to identify the photophysical mechanisms that can give rise to experimentally observed decay time constants. We first compute and theoretically assign the electronic spectra of uracil using the second-order algebraic-diagrammatic-construction (ADC(2)) method. The obtained electronic states, their energy differences and state-specific solvation effects are the prerequisites for understanding the photodynamics. We then use nonadiabatic trajectory-surface-hopping dynamics simulations to investigate the photoinduced dynamics of uracil and uracil-water clusters. In contrast to previous studies, we found that a single mechanism - the ethylenic twist around the C=C bond - is responsible for the ultrafast component of the nonradiative decay, both in the gas phase and in solution. Very good agreement with the experimentally determined ultrashort decay time constants is obtained. © the Owner Societies 2021.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy with nonadiabatic dynamics simulations to identify the photophysical mechanisms that can give rise to experimentally observed decay time constants. We first compute and theoretically assign the electronic spectra of uracil using the second-order algebraic-diagrammatic-construction (ADC(2)) method. The obtained electronic states, their energy differences and state-specific solvation effects are the prerequisites for understanding the photodynamics. We then use nonadiabatic trajectory-surface-hopping dynamics simulations to investigate the photoinduced dynamics of uracil and uracil-water clusters. In contrast to previous studies, we found that a single mechanism - the ethylenic twist around the C=C bond - is responsible for the ultrafast component of the nonradiative decay, both in the gas phase and in solution. Very good agreement with the experimentally determined ultrashort decay time constants is obtained. © the Owner Societies 2021. |
Popa, A; Borcanescu, S; Holclajtner-Antunović, I; Bajuk-Bogdanović, D; Uskoković-Marković, S Preparation and characterisation of amino-functionalized pore-expanded mesoporous silica for carbon dioxide capture Journal Article Journal of Porous Materials, 28 (1), pp. 143-156, 2021. @article{Popa2021143, title = {Preparation and characterisation of amino-functionalized pore-expanded mesoporous silica for carbon dioxide capture}, author = {A Popa and S Borcanescu and I Holclajtner-Antunović and D Bajuk-Bogdanović and S Uskoković-Marković}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090145787&doi=10.1007%2fs10934-020-00974-1&partnerID=40&md5=54b7bd1da07271c501d744cc45d6da6d}, doi = {10.1007/s10934-020-00974-1}, year = {2021}, date = {2021-01-01}, journal = {Journal of Porous Materials}, volume = {28}, number = {1}, pages = {143-156}, abstract = {In this study, the preparation of some large-pore ordered mesoporous silicas using a proper surfactant with different swelling agents was carried out. The synthesis of conventional SBA-15 was modified to obtain pore-expanded materials, with pore diameters up to 10 nm. To use a micelle swelling agent with a moderate swelling ability, three swelling agents were selected: 1-phenyl-decane (Dec), butyl benzene (BB), and mesitylene (Mes). These syntheses aimed to achieve a pore diameter enlargement but at the same time to avoid the formation of heterogeneous and/or poorly defined nanostructure of silica. The CO2 adsorbents were obtained by post-synthesis functionalization treatments carried out by grafting with 3-aminopropyl triethoxysilane. The CO2 adsorption/desorption experiments showed that carbon dioxide sorption capacities depend on the textural characteristics and the temperature used for the adsorption process. Good CO2 adsorption capacities were obtained for all prepared adsorbents, especially for SSBA-15-Mes-sil and SSBA-15-BB-sil samples. At 50 °C, the SSBA-15-Mes-sil sample has an adsorption capacity of 3.58 mmol CO2/g SiO2, and an efficiency of amino groups of 0.99 mmol CO2/mmol NH2. The results of adsorption capacities are comparable or even superior with the ones reported in literature for mesoporous silica functionalized with different amines. After nine adsorption–desorption cycles, the performance of the SSBA-15-Mes-sil adsorbent is relatively stable, with a low decrease in the adsorption capacity (0.1 mmol/g of CO2, i.e., 2.8% of initial capacity). These studies show the potential of mesoporous silica for carbon dioxide capture. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, the preparation of some large-pore ordered mesoporous silicas using a proper surfactant with different swelling agents was carried out. The synthesis of conventional SBA-15 was modified to obtain pore-expanded materials, with pore diameters up to 10 nm. To use a micelle swelling agent with a moderate swelling ability, three swelling agents were selected: 1-phenyl-decane (Dec), butyl benzene (BB), and mesitylene (Mes). These syntheses aimed to achieve a pore diameter enlargement but at the same time to avoid the formation of heterogeneous and/or poorly defined nanostructure of silica. The CO2 adsorbents were obtained by post-synthesis functionalization treatments carried out by grafting with 3-aminopropyl triethoxysilane. The CO2 adsorption/desorption experiments showed that carbon dioxide sorption capacities depend on the textural characteristics and the temperature used for the adsorption process. Good CO2 adsorption capacities were obtained for all prepared adsorbents, especially for SSBA-15-Mes-sil and SSBA-15-BB-sil samples. At 50 °C, the SSBA-15-Mes-sil sample has an adsorption capacity of 3.58 mmol CO2/g SiO2, and an efficiency of amino groups of 0.99 mmol CO2/mmol NH2. The results of adsorption capacities are comparable or even superior with the ones reported in literature for mesoporous silica functionalized with different amines. After nine adsorption–desorption cycles, the performance of the SSBA-15-Mes-sil adsorbent is relatively stable, with a low decrease in the adsorption capacity (0.1 mmol/g of CO2, i.e., 2.8% of initial capacity). These studies show the potential of mesoporous silica for carbon dioxide capture. © 2020, Springer Science+Business Media, LLC, part of Springer Nature. |
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 |