Publications by authors named "V P Bulychev"

In pandemic conditions, situation of active and uncontrolled use by population of antimicrobial preparations treating COVID-19 occurs. So, new risks of development of medication resistance among patients with various infectious diseases, tuberculosis included, appear. The purpose of the study is to characterize prevalence of antimicrobial preparations use by population in relationship with development of medication resistance in patients with tuberculosis during COVID-19 pandemic.

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Vibrational spectroscopic and average geometrical parameters of the strong H-bonded complexes [F(HF)] and [F(DF)] are determined for the first time from nine-dimensional (9D) perturbative and 6D variational calculations. The frequencies and intensities for all fundamental and some combination and overtone transitions obtained by the method of second-order vibrational perturbation theory (VPT2) are reported. A two-fold decrease in the H-F (D-F) stretching band frequency and a more than ten-fold increase in the intensity of this band upon complexation are predicted.

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The geometrical parameters, the frequencies, and absolute intensities of vibrational transitions of HO···trans-HONO hydrogen-bonded complex are calculated using the approach earlier tested in calculations of isolated molecules of nitrous acid and complexes of this acid with ammonia. The equilibrium nuclear configuration and potential energy and dipole moment surfaces are calculated by the MP2/aug-cc-pVTZ method with the basis set superposition error taken into account. The fundamental transition frequencies and intensities of the complex are first obtained in the harmonic approximation, and then the energy values, vibrational wave functions, and transition frequencies and intensities are determined from variational solutions of one- to four-dimensional anharmonic equations.

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The geometrical parameters, the frequencies, and absolute intensities for transitions between vibrational states of NH3···cis-HONO and NH3···cis-DONO hydrogen-bonded complexes are calculated using the approach earlier tested in calculations of isolated molecules of nitrous acid and the NH3···trans-HONO and NH3··trans-DONO complexes. Vibrational wave functions and energy values of the complexes are derived from variational solutions of anharmonic equations in one to four dimensions. The equilibrium nuclear configuration and potential energy surfaces are calculated by the MP2/aug-cc-pVTZ method with the basis set superposition error taken into account.

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The equilibrium nuclear configuration of the cis-DONO molecule is calculated in the MP2/aug-cc-pVTZ approximation. The main objective of this work is to calculate the frequencies and absolute intensities for fundamental transitions of cis-DONO, to examine the influence of H/D substitution on the form of vibrational modes and structural and spectral parameters, and to formulate a feasible and reliable approach for calculating such parameters of H-bonded complexes formed by cis-DONO. Vibrational wave functions and energy values of cis-DONO are derived from variational solutions of anharmonic equations in one to four dimensions with the potential energy surfaces calculated by the MP2/aug-cc-pVTZ method.

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