11 results match your criteria: "Taras Shevchenko National University of Kyiv 64[Affiliation]"
RSC Adv
December 2024
Taras Shevchenko National University of Kyiv 64, Volodymyrska Street Kyiv UA 01601 Ukraine
In the present manuscript, we highlight the contradictions in the thermally activated processes theory which treats a system's activated state as a state of the phonon subsystem. We offer an alternative model, in which the activated state is treated as an electron subsystem state. The mechanism of the activated state formation is as follows: thermal fluctuations excite electrons of some particles within the activation zone.
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August 2024
V. P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry, NAS of Ukraine 1 Academician Kukhar Str. Kyiv 02094 Ukraine
An efficient green approach for the trapping of generated -and -quinone methide intermediates by imidazoles and pyrazoles has been developed. A wide range of quinone methide precursors based on simple phenols are compatible with the experimental protocol under mild thermal conditions. This methodology was demonstrated to be suitable for the synthesis of methylene-linked benzopyrone-azole hybrids using naturally occurring coumarin and chromone Mannich bases.
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March 2023
Receptor.AI Inc. 20-22 Wenlock Road London N1 7GU UK
Accurate prediction of the drug-target affinity (DTA) is of critical importance for modern drug discovery. Computational methods of DTA prediction, applied in the early stages of drug development, are able to speed it up and cut its cost significantly. A wide range of approaches based on machine learning were recently proposed for DTA assessment.
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November 2021
International European University 42V, Akademika Hlushkova Ave Kyiv Ukraine.
Based on the analysis of dynamic properties of ionic liquid solutions, the descriptions of diffusion mechanisms are built for dimethylimidazolium chloride (dmim/Cl)-alcohol solute systems and the influence of the monohydric alcohols' molecular structure on their diffusion mechanisms in dmim/Cl-alcohol at = 400 K by molecular dynamics simulations are studied. From the analysis of radial distribution functions, MSDs, velocity autocorrelation function, and autocorrelation functions of dispersion we found that the motion of all components in IL dmim/Cl-alcohol (ethanol, propanol) systems at = 400 K occurs in the sub-diffuse regime and that the dynamics of the dmim/Cl-alcohol (ethanol, propanol) systems is heterogeneous. The increase of the alkyl chain length of the alcohol molecule does not affect the motion of the ionic liquid components; instead, it increases the characteristic times describing the model representation of alcohol molecule diffusion at short and medium times, without affecting diffusion mechanisms.
View Article and Find Full Text PDFMolecules
November 2021
Institute of Molecular Biology and Genetics, The NAS of Ukraine, 150 Zabolotnogo St., 03143 Kyiv, Ukraine.
() is a causative agent of many hospital- and community-acquired infections with the tendency to develop resistance to all known antibiotics. Therefore, the development of novel antistaphylococcal agents is of urgent need. Sortase A is considered a promising molecular target for the development of antistaphylococcal agents.
View Article and Find Full Text PDFChem Sci
November 2020
Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia Valencia Spain
A binary reversible switch between low-temperature multi-step spin crossover (SCO), through the evolution of the population () with high-spin (HS)-low-spin (LS) sequence: HSLS (state 1) ↔ HSLS (state 2) ↔ HSLS (state 3) ↔ HSLS (state 4) ↔ HSLS (state 5), and complete one step hysteretic spin transition featuring 20 K wide thermal hysteresis centred at 290 K occurs in the three-dimensional (3D) Hofmann-type porous coordination polymer {Fe(3,8phen)[Au(CN)]}·PhNO (3,8phen = 3,8-phenanthroline, PhNO = nitrobenzene), made up of two identical interpenetrated pcu-type frameworks. The included PhNO guest ( = 1, ) acts as a molecular wedge between the interpenetrated 3D frameworks PhNO-3,8phen intermolecular recognition and is the source of the strong elastic frustration responsible for the multi-step regime. Detailed X-ray single crystal analysis reflects competition between spatial periodicities of structurally inequivalent HS and LS SCO centres featuring: (i) symmetry breaking (state 3) with ⋯HS-LS⋯ ordering with = 1/2; and (ii) occurrence of spatial modulation of the structure providing evidence for stabilization of local or aperiodic ordered mixed spin states for states 2 and 4 (with ≈ 2/3) and 4 (with ≈ 1/3), respectively.
View Article and Find Full Text PDFThe aim of this work is to apply organic-inorganic hybrid salts made of imidazo[1,5-]pyridinium-based cations and halometallate anions as fluorescent agents to modify cross-linked polyurethane (CPU) for the creation of flexible photoluminescent films. The use of ionic compounds ensures excellent dispersion of the luminescent components in the polymer matrix and prevents solid-state quenching. The absence of phase segregation makes it possible to fabricate uniformly luminescent films with a large area.
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October 2020
Institute of Cell Biology and Genetic Engineering, NAS of Ukraine 148 Zabolotnogo Str. Kyiv 03143 Ukraine.
The research was focused on the synthesis of silver nanoparticles (AgNPs) using extracts from the "hairy" root cultures of Ledeb. and L. The effect of operational parameters such as type of solvent, temperature of extraction, flavonoids concentration, and reducing power of the wormwood "hairy" root extracts on the particle size and yield of the resultant nanoparticles is reported for the first time.
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June 2020
Department of Chemistry, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine
Materials that are able to switch microwave radiation are strongly desired for their potential applications in electronic devices. In this paper, we show the spin-dependant interaction of spin-crossover materials with microwave radiation, namely, the ability of coordination compounds [Fe(NHtrz)]Br and [Fe(NHtrz)](NO) that undergo a cooperative spin transition between low-spin and high-spin states to operate as thermoswitchable microwave absorbers. The characteristics of the microwave reflection and transmission of these spin-crossover complexes were investigated at variable temperatures.
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March 2019
Department of Materials Science and Engineering, Clemson University Clemson South Carolina 29634 USA
We have demonstrated the capability of a nanocomposite film made of a 2D array of Ag nanoparticles embedded into a poly(glycidyl methacrylate), PGMA, matrix to monitor the presence of organic vapors in the atmosphere. Specifically, changes in the extinction spectra of the submicron nanocomposite film are used to sense the vapors. The transformations of the spectra are fully reversible and reproducible upon multiple exposures.
View Article and Find Full Text PDFTalanta
September 2010
Institute of High Technology, Taras Shevchenko National University of Kyiv 64, Volodymyrska St, 01601 Kyiv, Ukraine.
A photoluminescence method to detect the toxic melamine contamination in fat watery milk has been proposed. Despite the quite different luminescence origins of milk and melamine patterns, their wide emission spectra under UV excitation are similar and in the range of 2.2-3.
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