425 research outputs found

    Experimental Research of the Diffraction and Vavilov-Cherenkov Radiation Generation in a Teflon Target

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    Geometry of Vavilov-Cherekov (VChR) radiation when an electron moves close to a dielectric target is in analogy to diffraction radiation (DR) geometry. In this case we may expect DR generation from the upstream face of the target besides that VChR. The joint observation of these booth types of radiation is very interesting from the pseudo-photon viewpoint, which is applicable for relativistic electrons. Unexpected results obtained in our experiment insist on reflection about nature both DR and VChR. The experiment was performed on the relativistic electron beam of the microtron of Tomsk Polytechnic University.Comment: This article will be published in Journal of Physic

    Diffraction of real and virtual photons in a pyrolytic graphite crystal as source of intensive quasimonochromatic X-ray beam

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    A series of experiments on the parametric X-rays radiation (PXR) generation and radiation soft component diffraction of relativistic electrons in pyrolytic graphite (PG) crystals have been carried out at the Tomsk synchrotronyesBelgorod State Universit

    The problem of individualization of legal entities in terms of innovative development of the Russian Federation and the European Union economy

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    This article is a comprehensive analytical study of the problem of individualization of legal entities in terms of innovative development of the Russian Federation and the European Union. Using the latest methodology of scientific research, the authors provide a justification of the legal institution of individualization, as well as offer a wide range of means of individualization of innovation actors and participants, including in the virtual space of the Internet.peer-reviewe

    Hydride-mediated reduction of 2,4,6-trinitrotoluene by yeasts as the way to its deep degradation

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    Broad screening of microorganisms from natural and anthropogenic ecological niches has revealed strains Candida sp. AN-L15 and Geotrichum sp. AN-Z4 which transform, 2,4,6-trinitrotoluene (TNT) via alternative pathways (with the domination of hydride ion-mediated reduction of the aromatic ring) and produce relatively high amounts of nitrites. According to the spectrophotometry data, the hydride attack of TNT by Candida sp. AN-L15 and Geotrichum sp. AN-Z4 grown at pH 5.0-8.0 leads to the mono-and dihydride complexes of TNT (H --TNT and 2H--TNT, respectively) and to protonated forms of the latter. Analysis by HPLC, GC-mass spectrometry, and ion chromatography revealed the products of deep conversion of TNT. The growth of the yeast strains in a weakly acidic medium with TNT (440 μM) is accompanied by formation of 2,4-dinitrotoluene (2,4-DNT, up to 18.2 μM). Together with accumulation of nitrites (up to 76.0 μM, depending on pH of the medium), these findings demonstrate the capacity of both strains for TNT denitration. Formation of 2,4-DNT reflects the realization of one of the possible mechanisms of TNT ortho-nitro group elimination and switching over to the pathways of metabolism of dinitrotoluenes, which are much more easily biodegradable than TNT. Simultaneously with the dominating TNT hydride attack, the mechanism of 4-and 6-electron reduction of the nitro group also functions in Candida sp. AN-L15 and Geotrichum sp. AN-Z4. Realization of the studied mechanisms of TNT transformation under growth of Candida sp. AN-L15 on n-alkane is important for bioremediation in the cases of combined pollution by oil products and explosives. © 2007 Pleiades Publishing, Ltd

    Application of Allogenic Adipose-Derived Multipotent Mesenchymal Stromal Cells from Cat for Tibial Bone Pseudoarthrosis Therapy (Case Report)

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    © 2016, Springer Science+Business Media New York.A clinical case reported here demonstrates the possibility of using the multipotent mesenchymal stromal cells obtained from the donor animal to stimulate the process of bone formation in surgical treatment of tibia pseudoarthrosis in the cat. The cells were isolated from adipose tissue of the donor cat and express on their surface main markers of mesenchymal stromal cells—CD 44 and Thy-1. As a result of manipulation, the bone regenerate was formed and the support function of the injured limb was restored

    Total cross sections for the reactions 10,11,12^{10,11,12}Be+28^{28}Si and 14^{14}B+28^{28}Si

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    In this paper, the results of measurements of the total cross sections for the reactions 10,11,12^{10,11,12}Be+28^{28}Si and 14^{14}B+28^{28}Si in the beam energy range 13A13A--47A47A MeV are presented. The experimental cross sections were obtained by detection of the gamma quanta and neutrons accompanying the interaction of the isotopes of Be and B with 28^{28}Si. It was found that the cross sections for 11,12^{11,12}Be are similar, but significantly exceed those for 10^{10}Be. A significant increase in the cross sections for 12^{12}Be with decreasing energy is observed in the entire measured energy range. A theoretical explanation of the obtained experimental data is given based on the microscopic model of deformed nuclei and the numerical solution of the time-dependent Schr\"{o}dinger equation for the outer weakly bound neutrons of the projectile nuclei. The calculated total reaction cross sections are in good agreement with the experimental data

    Aerobic degradation of 2,4,6-trinitrotoluene by the yeast strain Geotrichum candidum AN-Z4

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    The yeast strain Geotrichum candidum AN-Z4 isolated from an anthropogenically polluted site was able to transform 2,4,6-trinitrotoluene (TNT) via the formation of unstable intermediate hydride Meisenheimer complexes with their subsequent destruction and accumulation of nitrite and nitrate ions as the end mineral forms of nitrogen. Aeration of the medium promoted more profound destruction of this xenobiotic by the strain G. candidum AN-Z4 than static conditions. The yeast strain was shown to produce citrate, succinate, and isocitrate, which sharply acidified the medium and influenced the TNT destruction. Two possible pathways of TNT biodegradation were confirmed experimentally: (1) via the destruction of the TNT-monohydride complex (3-H--TNT) and (2) via the destruction of one protonated TNT-dihydride complex (3,5-2H--TNT · H+). The strain G. candidum AN-Z4, due to its ability for TNT degradation, may be promising for bioremediation of TNT-contaminated soil and water. © Pleiades Publishing, Ltd., 2010

    Cell surface engineering with polyelectrolyte-stabilized magnetic nanoparticles: A facile approach for fabrication of artificial multicellular tissue-mimicking clusters

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    © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg. Regenerative medicine requires new ways to assemble and manipulate cells for fabrication of tissue-like constructs. Here we report a novel approach for cell surface engineering of human cells using polymer-stabilized magnetic nanoparticles (MNPs). Cationic polyelectrolyte-coated MNPs are directly deposited onto cellular membranes, producing a mesoporous semi-permeable layer and rendering cells magnetically responsive. Deposition of MNPs can be completed within minutes, under cell-friendly conditions (room temperature and physiologic media). Microscopy (TEM, SEM, AFM, and enhanced dark-field imaging) revealed the intercalation of nanoparticles into the cellular microvilli network. A detailed viability investigation was performed and suggested that MNPs do not inhibit membrane integrity, enzymatic activity, adhesion, proliferation, or cytoskeleton formation, and do not induce apoptosis in either cancer or primary cells. Finally, magnetically functionalized cells were employed to fabricate viable layered planar (two-cell layers) cell sheets and 3D multicellular spheroids. [Figure not available: see fulltext.
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