Valeriy Sibirtsev

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Spectral data and nucleic acid complex formation properties for more than 30 both newly synthesized and widely used fluorescent nucleotide-specific compounds of various classes have been analyzed. These include phenylbenzene, bisbenzimidazole, psoralen, angelicin, tetrahydrocarbazole, oxophenoxazine, and others. The main rules of a generalized model(More)
The paper describes a system which uses a fact repository (FR) consisting of instances of ontological concepts to answer sequences of questions. The fact repository is populated automatically by analyzing texts to produce complex text meaning structures. These are then mapped to fact repository instances and stored in a relational database. The documents(More)
Absorption and fluorescence spectra for six new synthetic dyes of 4,8,4'-trimethylpsoralen and 4,4'-dimethylangelicin derivatives containing various terminal substituents at 5'-position have been investigated in different environments using a wide range of the DNA/ligand concentrations. Various spectral and binding characteristics of the DNA-ligand systems(More)
Changes in absorbance and fluorescence excitation and emission spectra in the ultraviolet and visible regions of the system containing ethidium bromide (EtBr) and Hoechst-33258 (Ht) were investigated depending on various DNA quantities and the composition of the medium. It is noted that spectral properties of this system are determined by interactions of(More)
Spectral properties of a series of externally binding substrate-specific bis-benzimidazole dyes that were either bound or not bound to DNA were studied. Feasible mechanisms of variation in fluorescent properties of the dyes under study were considered depending on their chemical structure. Contribution of the rotational diffusion and the donor-acceptor(More)
Various models of complex formation of low-molecular ligands with DNA are considered. Using the Scatchard model, parameters of binding of fluorescent monophenylindole, monophenylbenzimidazole, and bisbenzimidazole dyes with calf thymus DNA were evaluated. By means of graphic (nonparametric) and correlation analysis, various spectral and complexation(More)
The biological activity of cycloferon (CF) used in interferon manufacture has been investigated for its therapeutic and prophylactic properties which may be used for radiotherapy of glioma. It was demonstrated in experiments on rats that use of CF is most effective at an early stage of irradiation due to decrease in tumor mass which does not occur in case(More)
Mathematical and statistical procedures were used to identify individual response in rats to benzo(a)pyrene (BP) treatment versus dose and regimen (single or repeated administration). Primary experimental data were suitably processed to exclude extreme values. A significant correlation was established between life-span and urine level of(More)
A method for the analysis of microbial “growth curves” by real-time recording of changes in the impedance electrical conductance of the medium from multiple samples in parallel is described; these changes arise from metabolic processes taking place in the test microorganisms in the samples. Results obtained from practical application of the impedance(More)