1,047 research outputs found

    SOLUTION OF THE COUPLED THERMOMECHANICAL PROBLEM OF HYDRODYNAMICS FOR DESIGNING THE PROPULSION SYSTEM OF MICROSATELLITES

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    This paper considers the problem of predicting the technical and operating characteristics of the propulsion system of a microsatellite created by microelectronic technology. The coupled thermomechanical problem of hydrodynamics has been solved by the ANSYS CFX package. The microengine design has been optimized, the heating of its case in the operating time of the fuel chamber has been analyzed, and the velocity field distribution in the microengine nozzle has been determined. The values of the mechanical and temperature deformation fields for pure silicon and a silicon–SiO2 composite have been found, and the possibility in principle of operation of the considered device has been shown. The calculation was made on a triangular net

    Glatiramer Acetate and Nanny Proteins Restrict Access of the Multiple Sclerosis Autoantigen Myelin Basic Protein to the 26S Proteasome

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    © 2014 Ekaterina Kuzina et al. We recently showed that myelin basic protein (MBP) is hydrolyzed by 26S proteasome without ubiquitination. The previously suggested concept of charge-mediated interaction between MBP and the proteasome led us to attempt to compensate or mimic its positive charge to inhibit proteasomal degradation. We demonstrated that negatively charged actin and calmodulin (CaM), as well as basic histone H1.3, inhibit MBP hydrolysis by competing with the proteasome and MBP, respectively, for binding their counterpart. Interestingly, glatiramer acetate (GA), which is used to treat multiple sclerosis (MS) and is structurally similar to MBP, inhibits intracellular and in vitro proteasome-mediated MBP degradation. Therefore, the data reported in this study may be important for myelin biogenesis in both the normal state and pathophysiological conditions

    Deimination of the myelin basic protein decelerates its proteasome-mediated metabolism

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    © 2016, Pleiades Publishing, Ltd.Deimination of myelin basic protein (MBP) by peptidylarginine deiminase (PAD) prevents its binding to the proteasome and decelerates its degradation by the proteasome in mammalian cells. Potential anticancer drug tetrazole analogue of chloramidine 2, at concentrations greater than 1 µM inhibits the enzymatic activity of PAD in vitro. The observed acceleration of proteasome hydrolysis of MBP to antigenic peptides in the presence of PAD inhibitor may increase the efficiency of lesion of the central nervous system by cytotoxic lymphocytes in multiple sclerosis. We therefore suggest that clinical trials and the introduction of PAD inhibitors in clinical practice for the treatment of malignant neoplasms should be performed only after a careful analysis of their potential effect on the induction of autoimmune neurodegeneration processes

    Development of Education Districts in the Strategy of Strengthening the Axiological Foundations of the Russian Education Space

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    The article presents an analysis of the specific features of the socio-cultural modernization of education in contemporary Russia and the methodology of the development of the ethno-regional education systems against the background of strengthening the unified education space of Russia. Special attention is paid to the consideration of the strategy of the development of education districts of contemporary Russia as the foundation for building the government vertical of state management in the field of education.As part of the development of organizational and pedagogical resources of risk management of the gap between the scientific and education space of the country, the authors have worked out the idea of setting up scientific and education complexes and developing education districts in the country. This approach meets the objective of improving the quality of higher education in the regions of the country by establishing clear links with regional universities in the most “advanced” areas, organizing scientific and educational activities.Creating education districts serves as the foundation of building up a multicultural education space of the Russian Federation, the resource of lining up control at the federal and regional levels, the formation of a new vector of education policy focused on the preservation and development of a unified, internally differentiated scientific and education space of the country

    Transcription inactivation through local refolding of the RNA polymerase structure

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    Structural studies of antibiotics not only provide a shortcut to medicine allowing for rational structure-based drug design, but may also capture snapshots of dynamic intermediates that become 'frozen' after inhibitor binding. Myxopyronin inhibits bacterial RNA polymerase (RNAP) by an unknown mechanism. Here we report the structure of dMyx--a desmethyl derivative of myxopyronin B--complexed with a Thermus thermophilus RNAP holoenzyme. The antibiotic binds to a pocket deep inside the RNAP clamp head domain, which interacts with the DNA template in the transcription bubble. Notably, binding of dMyx stabilizes refolding of the beta'-subunit switch-2 segment, resulting in a configuration that might indirectly compromise binding to, or directly clash with, the melted template DNA strand. Consistently, footprinting data show that the antibiotic binding does not prevent nucleation of the promoter DNA melting but instead blocks its propagation towards the active site. Myxopyronins are thus, to our knowledge, a first structurally characterized class of antibiotics that target formation of the pre-catalytic transcription initiation complex-the decisive step in gene expression control. Notably, mutations designed in switch-2 mimic the dMyx effects on promoter complexes in the absence of antibiotic. Overall, our results indicate a plausible mechanism of the dMyx action and a stepwise pathway of open complex formation in which core enzyme mediates the final stage of DNA melting near the transcription start site, and that switch-2 might act as a molecular checkpoint for DNA loading in response to regulatory signals or antibiotics. The universally conserved switch-2 may have the same role in all multisubunit RNAPs

    The transcriptome of type i murine astrocytes under interferon-gamma exposure and remyelination stimulus

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    © 2017 by the authors.Astrocytes are considered to be an important contributor to central nervous system (CNS) disorders, particularly multiple sclerosis. The transcriptome of these cells is greatly affected by cytokines released by lymphocytes, penetrating the blood-brain barrier - in particular, the classical pro-inflammatory cytokine interferon-gamma (IFNγ). We report here the transcriptomal profiling of astrocytes treated using IFNγ and benztropine, a putative remyelinization agent. Our findings indicate that the expression of genes involved in antigen processing and presentation in astrocytes are significantly upregulated upon IFNγ exposure, emphasizing the critical role of this cytokine in the redirection of immune response towards self-antigens. Data reported herein support previous observations that the IFNγ-induced JAK-STAT signaling pathway may be regarded as a valuable target for pharmaceutical interventions

    Modified siRNA effectively silence inducible immunoproteasome subunits in NSO cells

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    © 2016 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.The pathogenesis of autoimmune and neurodegenerative diseases involves overexpression of inducible subunits of the immunoproteasome. However, the clinical application of inhibitors to inducible subunits of the immunoproteasome has been limited due to systemic toxicity. Here, we designed siRNAs that efficiently silence LMP2, LMP7 and MECL-1 gene expression. Inducible subunits of the immunoproteasome are complex siRNA targets because they have a long half-life; therefore, we introduced 2′-O-methyl modifications into nuclease-sensitive sites. This led to 90-95% silencing efficiency and prolonged silencing, eliminating the need for multiple transfections. Furthermore, we showed that in the absence of transfection reagent, siRNAs with lipophilic residues were able to penetrate cells more effectively and decrease the expression of inducible immunoproteasome subunits by 35% after 5 days. These results show that siRNA targeted to inducible immunoproteasome subunits have great potential for the development of novel therapeutics for autoimmune and neurodegenerative diseases

    mRNA expression profile of mouse oligodendrocytes in inflammatory conditions

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    © 2016, Pleiades Publishing, Ltd.In this study, we performed transcriptome profiling of oligodendrocyte culture of mice treated with the remyelinating therapeutic agent benztropine in the presence and absence of interferon gamma (IFNγ). The results of this work are important for understanding the expression profile of oligodendrocytes under conditions of systemic inflammation in the central nervous system in multiple sclerosis as well as the mechanisms of cellular response to benztropine in light of its possible use for the treatment of multiple sclerosis

    Flux Modulations seen by the Muon Veto of the GERDA Experiment

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    The GERDA experiment at LNGS of INFN is equipped with an active muon veto. The main part of the system is a water Cherenkov veto with 66~PMTs in the water tank surrounding the GERDA cryostat. The muon flux recorded by this veto shows a seasonal modulation. Two effects have been identified which are caused by secondary muons from the CNGS neutrino beam (2.2 %) and a temperature modulation of the atmosphere (1.4 %). A mean cosmic muon rate of Iμ0=(3.477±0.002stat±0.067sys)×104I^0_{\mu} = (3.477 \pm 0.002_{\textrm{stat}} \pm 0.067_{\textrm{sys}}) \times 10^{-4}/(s\cdotm2^2) was found in good agreement with other experiments at LNGS at a depth of 3500~meter water equivalent.Comment: 7 pages, 6 figure

    Characterization of 30 76^{76}Ge enriched Broad Energy Ge detectors for GERDA Phase II

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    The GERmanium Detector Array (GERDA) is a low background experiment located at the Laboratori Nazionali del Gran Sasso in Italy, which searches for neutrinoless double beta decay of 76^{76}Ge into 76^{76}Se+2e^-. GERDA has been conceived in two phases. Phase II, which started in December 2015, features several novelties including 30 new Ge detectors. These were manufactured according to the Broad Energy Germanium (BEGe) detector design that has a better background discrimination capability and energy resolution compared to formerly widely-used types. Prior to their installation, the new BEGe detectors were mounted in vacuum cryostats and characterized in detail in the HADES underground laboratory in Belgium. This paper describes the properties and the overall performance of these detectors during operation in vacuum. The characterization campaign provided not only direct input for GERDA Phase II data collection and analyses, but also allowed to study detector phenomena, detector correlations as well as to test the strength of pulse shape simulation codes.Comment: 29 pages, 18 figure
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