147 research outputs found

    Abnormal methylation of PRDM16 and PTPRN2 genes in chorionic villi in miscarriage

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    Relevance. Abnormal epigenetic regulation of genes responsible for the development of the embryo and placenta is associated with many pregnancy pathologies. Aim. The aim of this work was to analyze the prevalence of abnormal methylation of the PRDM16 and PTPRN2 genes in chorionic villi of spontaneous abortions with normal karyotype and with the most frequent aneuploidies (trisomy 16 and monosomy X). Materials and Methods. The methylation profile was evaluated using targeted bisulfite massive parallel sequencing in chorionic villi of induced abortions (n = 10), spontaneous abortions with normal karyotype (n = 39), trisomy 16 (n = 17) and monosomy X (n = 20) and peripheral blood lymphocytes of healthy volunteers (n = 6). Results and Discussion. In analyzed genes, differential methylation of individual CpG sites was found in chorionic villi of spontaneous abortions. Despite the absence of significant differences between the groups in the average level of methylation in analyzed gene regions, abnormal methylation of the PRDM16 and PTPRN2 genes were detected for 33 % and 5 % of spontaneous abortions, respectively, indicating a high incidence of epigenetic abnormalities in these genes in the chorionic villi of spontaneous abortions. The level of methylation of the PRDM16 gene significantly correlated with the level of methylation of the retrotransposon LINE-1, which indicates the generalized nature of methylation disorders in spontaneous abortions. Finally, the level of methylation of the PTPRN2 gene depended on the age of mothers of spontaneous abortions with monosomy X, which raises the question of the influence of maternal factors on the methylation profile in this group of spontaneous abortions. Conclusion. The results indicate that epigenetic disorders of the PRDM16 gene may be associated with spontaneous termination of pregnancy in the first trimester

    Polarized blazar X-rays imply particle acceleration in shocks

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    Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier1,2,3, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree ΠX of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock

    X-ray Polarization Observations of BL Lacertae

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    Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus the Synchrotron emission to be responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae performed with the Imaging X-ray Polarimetry Explorer ({IXPE}), from which an upper limit to the polarization degree ΠX<\Pi_X<12.6\% was found in the 2-8 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac.Comment: 17 pages, 5 figures, accepted for publication in ApJ

    MECHANISM OF INVESTMENT ACTIVITY SYSTEMS ORGANIZATION IN REGION

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    The concept of the systems organization mechanism of the investment activity in the region is consid ered. The b asic elements which are necessary and sufficient for the effective functioning of the given system are briefly d escribed. The main actions realized in the Rostov region for the improvement of the business mechanis m of spurring the investment activity are analyzed

    Development and Approbation of Methods and Technical Solutions of Reduction of Vibration of Power Plants and Joining Mechanical Systems

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    AbstractPower plants of different kinds are widely used in modern machinery, energetic, chemical industry, other branches, in transport and domestic conditions. Vibration and related with it mechanical noise of power plants and joining mechanical systems are the factors negatively impacted to the durability, reliability, productivity and other parameters of power plants. Methodological basics of methods of power plants vibration and mechanical noise complex reduction developed by author are described. According to the energetic criteria it is suggested to classify methods of vibration reduction as passive, active and hybrid (active-passive). Technical solutions for vibration reduction developed by author and results of it approbation are described. Results of approbation are confirming sufficiently high efficiency of technical solutions

    Method and Approaches to the Estimation of Ecological Risks of Urban Territories

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    Negative environmental factors (chemical, physical, biological) may cause significant negative influence both over environment and the health of the population. Maximal number of sources of negative impact is located in industrial regions. Factors and existing methods of the estimation of ecological risks of urban territories are discussed. The main steps of estimation of ecological risks of urban territories are described. New approaches to estimation of ecological risks of urban territories are suggested. Program provision has been developed for the estimation of ecological risks allowing to forecast the level of pollutions of the environment of urban territories. The results of approbation of the new method and program provision of estimation of ecological risks on the example of the territory of Samara region of Russia have been described
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