10 research outputs found

    Effects of hydrodynamic impact on water from the viewpoint of cluster theory. Surface tension

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    Variation of surface tension coefficient ? of distilled water under high-energy impact (hydrodynamic cavitation) was studied by the ring separation method. Force impacts on surface tension of water have been studied experimentally. Conditions have been found under which the surface tension coefficient ? decreases to 20%. The paper explains the produced results on the basis of cluster theory of water structure. The experimentally produced relaxation time of the surface tension of cavitation-activated distilled water to initial value has been found to be 3.5 hour

    Nonequilibrium carbon black suspensions used in synthesis of polymer composite material

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    Nowadays polymer matrix-based composite material with various carbon fillers are widely used to protect radioequipment from different interference, to improve characteristics of radar absorbing coatings. Current synthesis processes are sophisticated and rather costly. The challenge is to develop new methods of producing composite materials by efficient knowledge intensive technologies to reduce the cost of products. The paper studies possibility of producing composite material on the basis of elastic polyurethane foam with carbon fillers using polyurethane impregnation in nonequilibrium black carbon suspension. Suspension composition: running water and carbon-bearing powders of nanometer range: fullerene black carbon, Taunite (multi-layer carbon nano tube material), technical carbon T900, wood soot. Nonequilibrium suspension was produced by treatment in hydrodynamic generator of rotor type (cavitation mode). Angular rotation speed of the rotor ω = 10000 rpm

    NETWORK APPROACH TO ANALYSIS OF QUANTITATIVE TRAIT LOCI FOR TUMOR NECROSIS FACTOR (TNFα-863, TNFα-308, TNFα-238), VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF-2578, VEGF+936) AND MATRIX METALLOPROTEINASE (ММР2-1306, ММР3-1171, ММР9-1569) GENES IN AGERELATED MACULAR DEGENERATION

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    Age-related macular degeneration is one of the most widespread multifactorial eye diseases. Polymorphic functional alleles of vascular endothelial growth factor (VEGF) combined with matrix metalloproteinase (MMP) gene and tumor necrosis factor (TNF) gene variants may influence the development of disease. We have performed frequency analysis of their polymorphisms in regulatory regions of VEGF (rs 699947, rs 3025039), ММР2 (rs 2438650), ММР3 (rs 3025058), ММР9 (rs 3918242), TNFα (rs1800630, rs1800629, rs 361525) genes, and their combinations in a group of patients with age-related macular degeneration (MD). Frequencies of TNFα (rs1800629) genotypes significantly differed for the MD patients and control group. Upon the combined genotype analysis, we have revealed six constellations of VEGF-ММР genes that were positively associated with the disease development. Five of them included minor homozygous genotype VEGF-2578АА. A combined analysis of VEGF – TNFα genes polymorphisms has shown presence of both positive and negative complex genotypes. The most significant differences have been detected by comparative analysis of the complex genotypes frequencies which included 8 polymorphic regulatory gene regions of all genes studied. In most genetic complexes associated with the disease development, homozygous TNFα-863СС, homozygous MMP2-1306 ТТ, and MMP9-1562СС genotypes have been detected, together with the combination of homozygous VEGFA+936СС genotype in the same patients. We can assume that harboring allelic variants, which may contribute to angiogenesis prorcesses is typical for the genome of patients with macular degeneration, along with low-level production of pro-inflammatory regulatory factors and enzymes participating in degradation of extracellular matrix. Analysis of complex genetic factors, procing some factors taking part at the pathological process being the regulators of production for each other, is more informative when detecting protective and resistant markers of the disease development rather than single genetic markers, thus being useful for genomic screening

    Molecular basis of microhomology-mediated end-joining by purified full-length Polθ

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    DNA polymerase θ (Polθ) is a unique polymerase-helicase fusion protein that promotes microhomology-mediated end-joining (MMEJ) of DNA double-strand breaks (DSBs). How full-length human Polθ performs MMEJ at the molecular level remains unknown. Using a biochemical approach, we find that the helicase is essential for Polθ MMEJ of long ssDNA overhangs which model resected DSBs. Remarkably, Polθ MMEJ of ssDNA overhangs requires polymerase-helicase attachment, but not the disordered central domain, and occurs independently of helicase ATPase activity. Using single-particle microscopy and biophysical methods, we find that polymerase-helicase attachment promotes multimeric gel-like Polθ complexes that facilitate DNA accumulation, DNA synapsis, and MMEJ. We further find that the central domain regulates Polθ multimerization and governs its DNA substrate requirements for MMEJ. These studies identify unexpected functions for the helicase and central domain and demonstrate the importance of polymerase-helicase tethering in MMEJ and the structural organization of Polθ

    Gabuda’s model of averaging local magnetic fields in solid-state NMR. The mobility of atoms and molecules

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