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28 results on '"Gushchina, Irina"'

3. Direct Band Gap Chalcohalide Semiconductors: Quaternary AgBiSCl2 Nanocrystals

Author

Quarta, Danila, primary, Toso, Stefano, additional, Fieramosca, Antonio, additional, Dominici, Lorenzo, additional, Caliandro, Rocco, additional, Moliterni, Anna, additional, Tobaldi, David Maria, additional, Saleh, Gabriele, additional, Gushchina, Irina, additional, Brescia, Rosaria, additional, Prato, Mirko, additional, Infante, Ivan, additional, Cola, Adriano, additional, Giannini, Cinzia, additional, Manna, Liberato, additional, Gigli, Giuseppe, additional, and Giansante, Carlo, additional

Published
2023
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9. The social capital impact on the effectiveness of university departments

Author

Agapova Elena, Zharova Marina, Gushchina Irina, Ivanova Ekaterina, and Kravtsova Natalia

Subjects
Environmental sciences, GE1-350
Abstract

The article presents the results of assessing the level of social capital of a university department, the mutual influence of the type of organizational culture and the effectiveness of its work. In the course of the study, the concept of social capital was generalized and refined in the context of the concept of sustainable education, as well as in relation to an educational institution, to the community of a higher educational organization. There were tested the ideas of N.P. Makarkin and O.B. Tomilina about the impact of organizational culture on the efficiency of the university. To ensure the comparison of the different departments data with each other there was proposed a method for bringing to a single scale of assessments and calculating weighted average indicators, which made it possible to derive a single integral assessment of the social capital of a department/unit.

Published
2020
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21. Inhibitory Effect of New Semisynthetic Usnic Acid Derivatives on Human Tyrosyl-DNA Phosphodiesterase 1

Author

Dyrkheeva, Nadezhda, additional, Luzina, Olga, additional, Filimonov, Aleksandr, additional, Zakharova, Olga, additional, Ilina, Ekaterina, additional, Zakharenko, Alexandra, additional, Kuprushkin, Maxim, additional, Nilov, Dmitry, additional, Gushchina, Irina, additional, Švedas, Vytas, additional, Salakhutdinov, Nariman, additional, and Lavrik, Olga, additional

Published
2018
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23. Inhibitory Effect of New Semisynthetic Usnic Acid Derivatives on Human Tyrosyl-DNA Phosphodiesterase 1.

Author

Dyrkheeva, Nadezhda, Luzina, Olga, Filimonov, Aleksandr, Zakharova, Olga, Ilina, Ekaterina, Zakharenko, Alexandra, Kuprushkin, Maxim, Nilov, Dmitry, Gushchina, Irina, Švedas, Vytas, Salakhutdinov, Nariman, and Lavrik, Olga

Subjects
TERPENES, LICHEN physiology, CELL lines, MOLECULAR structure, PHENOLS, RECOMBINANT proteins, TUMORS, PHYTOCHEMICALS, PLANT extracts, PHOSPHODIESTERASE inhibitors, PHARMACODYNAMICS, THERAPEUTICS
Abstract

Usnic acid, a lichen secondary metabolite produced by a whole number of lichens, has attracted the interest of researchers owing to its broad range of biological activity, including antiviral, antibiotic, anticancer properties, and it possessing a certain toxicity. The synthesis of new usnic acid derivatives and the investigation of their biological activity may lead to the discovery of compounds with better pharmacological and toxicity profiles. In this context, a series of new usnic acid derivatives comprising a terpenoid moiety were synthesized, and their ability to inhibit the catalytic activity of the human DNA repair enzyme tyrosyl-DNA phosphodiesterase 1 was investigated. The most potent compounds (15a, 15b, 15g,and 16a, 16b, 16g) had IC50 values in the range of 0.33-2.7 µM. The inhibitory properties were mainly dependent on the flexibility and length of the terpenoid moiety, but not strongly dependent on the configuration of the asymmetric centers. The synthesized derivatives showed low cytotoxicity against human cell lines in an MTT assay. They could be used as a basis for the development of more effective anticancer therapies when combined with topoisomerase 1 inhibitors. [ABSTRACT FROM AUTHOR]

Published
2019
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26. Excitation Intensity- and Size-Dependent Halide Photosegregation in CsPb(I0.5Br0.5)3Perovskite Nanocrystals

Author

Gushchina, Irina, Trepalin, Vadim, Zaitsev, Evgenii, Ruth, Anthony, and Kuno, Masaru

Abstract

Although broad consensus exists that photoirradiation of mixed-halide lead perovskites leads to anion segregation, no model today fully rationalizes all aspects of this near ubiquitous phenomenon. Here, we quantitatively compare experimental, CsPb(I0.5Br0.5)3nanocrystal (NC) terminal anion photosegregation stoichiometries and excitation intensity thresholds to a band gap-based, thermodynamic model of mixed-halide perovskite photosegregation. Mixed-halide NCs offer strict tests of theory given physical sizes, which dictate local photogenerated carrier densities. We observe that mixed-anion perovskite NCs exhibit significant robustness to photosegregation, with photosegregation propensity decreasing with decreasing NC size. Observed size- and excitation intensity-dependent photosegregation data agree with model predicted size- and excitation intensity-dependent terminal halide stoichiometries. Established correspondence between experiment and theory, in turn, suggests that mixed-halide perovskite photostabilities can be predicted a priori using local gradients of (empirical) Vegard’s law expressions of composition-dependent band gaps.

Published
2022
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27. Mixed Ligand Passivation as the Origin of Near-Unity Emission Quantum Yields in CsPbBr 3 Nanocrystals.

Author

Ding Y, Zhang Z, Toso S, Gushchina I, Trepalin V, Shi K, Peng JW, and Kuno M

Abstract

Key features of syntheses, involving the quaternary ammonium passivation of CsPbBr 3 nanocrystals (NCs), include stable, reproducible, and large (often near-unity) emission quantum yields (QYs). The archetypical example involves didodecyl dimethyl ammonium (DDDMA + )-passivated CsPbBr 3 NCs where robust QYs stem from interactions between DDDMA + and NC surfaces. Despite widespread adoption of this synthesis, specific ligand-NC surface interactions responsible for large DDDMA + -passivated NC QYs have not been fully established. Multidimensional nuclear magnetic resonance experiments now reveal a new DDDMA + -NC surface interaction, beyond established "tightly bound" DDDMA + interactions, which strongly affects observed emission QYs. Depending upon the existence of this new DDDMA + coordination, NC QYs vary broadly between 60 and 85%. More importantly, these measurements reveal surface passivation through unexpected didodecyl ammonium (DDA + ) that works in concert with DDDMA + to produce near-unity (i.e., >90%) QYs.

Published
2023
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28. Excitation Intensity- and Size-Dependent Halide Photosegregation in CsPb(I 0.5 Br 0.5 ) 3 Perovskite Nanocrystals.

Author

Gushchina I, Trepalin V, Zaitsev E, Ruth A, and Kuno M

Abstract

Although broad consensus exists that photoirradiation of mixed-halide lead perovskites leads to anion segregation, no model today fully rationalizes all aspects of this near ubiquitous phenomenon. Here, we quantitatively compare experimental, CsPb(I 0.5 Br 0.5 ) 3 nanocrystal (NC) terminal anion photosegregation stoichiometries and excitation intensity thresholds to a band gap-based, thermodynamic model of mixed-halide perovskite photosegregation. Mixed-halide NCs offer strict tests of theory given physical sizes, which dictate local photogenerated carrier densities. We observe that mixed-anion perovskite NCs exhibit significant robustness to photosegregation, with photosegregation propensity decreasing with decreasing NC size. Observed size- and excitation intensity-dependent photosegregation data agree with model predicted size- and excitation intensity-dependent terminal halide stoichiometries. Established correspondence between experiment and theory, in turn, suggests that mixed-halide perovskite photostabilities can be predicted a priori using local gradients of (empirical) Vegard's law expressions of composition-dependent band gaps.

Published
2022
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