Publications by authors named "Bulgakova V"

Diamond is a promising material for terahertz applications. In this work, we use a non-invasive optical pump-terahertz probe method to experimentally study the photoinduced carrier dynamics in doped diamond monocrystals and a new diamond-silicon composite. The chemical vapor deposited diamond substrate with embedded silicon microparticles showed two photoinduced carrier lifetimes (short lifetime on the order of 4 ps and long lifetime on the order of 200 ps).

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Aim: An analysis of coronavirus infection in Russia and evaluation of different AVT regimens effectiveness.

Materials And Methods: The study involved a retrospective analysis of 1082 patient records with laboratory-confirmed COVID-19 in 17 regions of Russia. The number of men and women was equal, mean age 48.

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The generation of terahertz radiation in a photoconductive emitter based on nitrogen-doped single-crystal diamond was realized for the first time. Under 400 nm femtosecond laser pumping, the performance of diamond antennas with different dopant levels was investigated and compared with a reference ZnSe antenna. Terahertz waveforms and corresponding spectra were measured.

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Coronaviruses are known to cause acute respiratory infections. Antiviral therapy, including for COVID-19, is based on clinical practice, experimental data and trial results. The purpose of this review is to: provide and systematize actual preclinical data, clinical trials results and clinical practice for antiviral agent umifenovir (Arbidol).

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Hybrid organic-inorganic perovskites, while well examined for photovoltaic applications, remain almost completely unexplored in the terahertz (THz) range. These low-cost hybrid materials are extremely attractive for THz applications because their optoelectronic properties can be chemically engineered with relative ease. Here, we experimentally demonstrate the first attempt to apply solution-processed polycrystalline films of hybrid perovskites for the development of photoconductive terahertz emitters.

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Aim: to determine the perspectives for the use of drugs with combined antiviral, anti - inflammatory and immunomodulatory activity on the basis of medical studies of existing antiviral drugs for the treatment of influenza and acute respiratory viral infections in Russia.

Materials And Methods: A brief review of the antiviral drugs used in Russia for the treatment of influenza and acute respiratory viral infections was conducted on the basis of 37 articles published in Scopus, Web of Science (WoS), and RSCI databases in the period from 1997 to 2018.

Results: Resistance to neuraminidase inhibitors (oseltamivir, zanamivir), is slowly developing due to the mutations of the neuraminidase gene H275Y and Q136K.

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Aim: The aim of the study is to obtain additional data on safety and therapeutic efficacy of the antiviral drug Arbidol (umifenovir) in patients with a diagnosis of influenza and common cold.

Materials And Methods: Double-blind, randomized, placebo-controlled clinical study investigating efficacy and safety of Arbidol (umifenovir) in Treatment and Prophylaxis of Influenza and Common Cold (ARBITR) IV phase started in November 2011 and completed in April 2016 on the basis of 15 research centers in various regions of the Russian Federation. A total of 359 patients, aged 18 to 65 years with influenza or acute respiratory tract infection, of no more than 36 hours' duration were enrolled in the study.

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Influence of bronchial asthma (BA) severity on physical development in children patients was evaluated in comparison with healthy population. . 1042 children and adolescents (768 boys) with atopic BA were evaluated.

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Aim: To identify risk factors (RFs) for the development of bacterial complications and the prolonged course of influenza and other acute respiratory viral infections (ARVIs) among inpatients treated in Russian healthcare facilities in the post-pandemic period; to determine the clinical presentation of the disease (flu-like syndrome) in risk-group people and to evaluate the efficacy of antiviral therapy with arbidol (umifenovir).

Material And Methods: The investigators retrospectively analyzed randomly selected medical records of inpatients with influenza and other ARVI in 88 hospitals from 50 regions of the Russian Federation: those of 3532 and 1755 patients in the 2010-2011 and 2014-2015 seasons, respectively, by applying parametric and nonparametric statistical methods.

Results: The built database of patients with influenza-like syndrome contained data from the histories of 2072 men and 2537 women, of whom there were 317 (12.

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Review represents data on new active metabolites isolated from marine actinomycetes published in 2007 to 2014. Marine actinomycetes are an unlimited source of novel secondary metabolites with various biological activities. Among them there are antibiotics, anticancer compounds, inhibitors of biochemical processes.

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Streptomycetes or mycelial microorganisms are able to form biofilms under the natural, industrial and clinical conditions. The controlled use of biofilms in various industrial processes is much more efficient vs. the cultivation of plankton suspended cells.

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Data on the pharmacogenetic markers of the effectiveness of treatment of children with atopic asthma are presented, which reveal a variability of the response to treatment with glucocorticosteroids, leukotriene receptor antagonists, and b2-adrenoreceptor agonists in children with bronchial asthma. The association of genotype Gly/Glyl6 gene b2-adrenergic receptor with insufficient effect of the therapy with short-acting b2-agonists is demonstrated. The Glyl6 allele, CYP2D6 - 1934GGd contributes to the formation of a phenotype with severe asthma and tolerance to therapy with b2-agonists and inhaled corticosteroids.

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Marine-derived fungi are of great interest as a new promising source of biologically active products such as anticancer compounds, antibiotics, inhibitors of biochemical processes. Since marine organisms inhabit biologically competitive environment with unique conditions, the chemical diversity of the secondary metabolites from marine fungi is considerably high. Recent genomic studies demonstrated that fungi can carry gene clasters encoding production of previously unknown secondary metabolites.

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The review concerns discussion of certain aspects of growth and development of streptomycetes, that have an adaptation meaning for their existence under natural conditions and reflect our perception of them as procaryotes which have a range of qualities typical of multicellular organisms. At present, the concept of multicellularity is the key idea in investigation of growth processes, differentiation and physiology of streptomycetes. Streptomyces olivocinereus is presented as an effective model that gives the unique opportunities for investigation of different aspects of biology of streptomycetes within laboratory environment as well as in natural environment in suli.

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Streptomycetes, soil-dwelling mycelial bacteria, can form biofilms as indigenous components of the environment. The biofilms formed by streptomycetes exist in different ecological niches, in natural, medical, industrial environments. The biofilm-forming streptomycetes affect water quality, human health, associate with deterioration of artworks and historical monuments.

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The major characteristics of new bioactive microbial secondary metabolites are summarized in the review. A wide range of new molecular targets are implicated in discovery of new nonantibiotic compounds with some other pharmacological activities (noninfectious diseases). Microorganisms represent fascinating resources due to their production of novel products with broad spectra of bioactivities.

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It was thought that antibiotics should be produced by soil microorganisms to inhibit the growth of competitors in natural habitats. Yet it has been shown that antibiotics at subinhibitory concentrations may have a role as signalling molecules providing cell-to-cell communication in bacteria in the environment. Antibiotics modulate gene transcription and regulate gene expression in microbial populations.

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The review gives the results of a many-sided study of the basic properties of the therapeutic molecule of azoximer bromide (polyoxidonium). It analyzes our experience with the immunomodulator used to treat acute respiratory infections. Polyoxidonium has marked immunomodulatory (including interferon-producing) activity and a nonspecific protective effect against a broad range of pathogens, which is based on the regulation of systemic immunity rather than the direct inhibition of microorganisms.

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The third part of the review is concerned with investigation of nonribosomal peptides.

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The known conceptions of resistome as a complex of all the antibiotic resistance genes in the genomes of all the microorganisms, pathogenic and nonpathogenic ones, in nature are considered. The data on the origin, evolution and distribution of antibiotic resistance genes and possible approaches to the resistance distribution control are presented.

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The data on novel polypeptide antibiotics described within the last 10-15 years, as well as new researches on the known antibiotics with respect to their mechanisms of action and microbial resistance are presented.

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Cell walls of Staphylococcus aureus R9/80 resistant to gramicidin S and actinomycin D were investigated. The strain was isolated after passages of a previously isolated strain of S. aureus with resistance to gramicidin and definite changes in the cell walls, a medium with increasing concentrations of actinomycin being used for the passages.

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The impact of glycine, added to the cultivation medium, on resistance of Staphylococcus aureus strains to actinomycin D and gramicidin S was studied. The antibiotic resistant strains were isolated after cultivation of the susceptible S. aureus strain 209P on media with increasing concentrations of actinomycin or gramicidin.

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