1,123 research outputs found

    Clustering in light nuclei in fragmentation above 1 A GeV

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    The relativistic invariant approach is applied to analyzing the 3.3 A GeV 22^{22}Ne fragmentation in a nuclear track emulsion. New results on few-body dissociations have been obtained from the emulsion exposures to 2.1 A GeV 14^{14}N and 1.2 A GeV 9^{9}Be nuclei. It can be asserted that the use of the invariant approach is an effective means of obtaining conclusions about the behavior of systems involving a few He nuclei at a relative energy close to 1 MeV per nucleon. The first observations of fragmentation of 1.2 A GeV 8^{8}B and 9^{9}C nuclei in emulsion are described. The presented results allow one to justify the development of few-body aspects of nuclear astrophysics.Comment: 7 pages, 8 figures, 3 tables, Nuclear Physics in Astrophysics-2, 16-20 May, 2005 (ATOMKI), Debrecen, Hungar

    Double-spiral magnetic structure of the Fe/Cr multilayer revealed by nuclear resonance scattering

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    We have studied the magnetization depth profiles in a [57Fe(dFe)/Cr(dCr)]x30 multilayer with ultrathin Fe layers and nominal thickness of the chromium spacers dCr 2.0 nm using nuclear resonance scattering of synchrotron radiation. The presence of a broad pure-magnetic half-order (1/2) Bragg reflection has been detected at zero external field. The joint fit of the reflectivity curves and Mossbauer spectra of reflectivity measured near the critical angle and at the "magnetic" peak reveals that the magnetic structure of the multilayer is formed by two spirals, one in the odd and another one in the even iron layers, with the opposite signs of rotation. The double-spiral structure starts from the surface with the almost antiferromagnetic alignment of the adjacent Fe layers. The rotation of the two spirals leads to nearly ferromagnetic alignment of the two magnetic subsystems at some depth, where the sudden turn of the magnetic vectors by ~180 deg (spin-flop) appears, and both spirals start to rotate in opposite directions. The observation of this unusual double-spiral magnetic structure suggests that the unique properties of giant magneto-resistance devices can be further tailored using ultrathin magnetic layers.Comment: 9 pages, 3 figure

    Fragmentation of relativistic nuclei in peripheral interactions in nuclear track emulsion

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    The technique of nuclear track emulsions is used to explore the fragmentation of light relativistic nuclei down to the most peripheral interactions - nuclear "white" stars. A complete pattern of therelativistic dissociation of a 8^8B nucleus with target fragment accompaniment is presented. Relativistic dissociation 9^{9}Be2α\to2\alpha is explored using significant statistics and a relative contribution of 8^{8}Be decays from 0+^+ and 2+^+ states is established. Target fragment accompaniments are shown for relativistic fragmentation 14^{14}N\to3He+H and 22^{22}Ne\to5He. The leading role of the electromagnetic dissociation on heavy nuclei with respect to break-ups on target protons is demonstrated in all these cases. It is possible to conclude that the peripheral dissociation of relativistic nuclei in nuclear track emulsion is a unique tool to study many-body systems composed of lightest nuclei and nucleons in the energy scale relevant for nuclear astrophysics.Comment: 15 pages, 4 figures, 4 tables, conference: Relativistic nuclear physics: from Nuclotron to LHC energies, Kiev, June 18-22, 200

    Autoimmune polyglandular syndrome type 1 and eye damage

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    Autoimmune polyendocrine syndrome type 1 (APS type 1) is a disease characterized by a variety of clinical manifestations resulting from the involvement of multiple endocrine and non-endocrine organs in the pathological process. APS type 1 is a rare genetically determined disease with autosomal recessive inheritance. Mutations in the autoimmune regulator gene (AIRE) lead to a disruption of the mechanism of normal antigen expression and the formation of abnormal clones of immune cells, and can cause autoimmune damage to organs. Within APS type 1, the most common disorders are primary adrenal insufficiency, hypoparathyroidism, and chronic candidiasis. Some understudied clinical manifestations of APS type 1 are autoimmune pathological processes in the eye: keratoconjunctivitis, dry eye syndrome, iridocyclitis, retinopathy, retinal detachment, and optic atrophy. This review presents the accumulated experimental and clinical data on the development of eye damage of autoimmune nature in APS type 1, as well as the laboratory and instrumental methods used for diagnosing the disease. Changes in the visual organs in combination with clinical manifestations of hypoparathyroidism, adrenal insufficiency and candidiasis should lead the clinical doctor to suspect the presence of APS type 1 and to examine the patient comprehensively. Timely genetic counselling will allow early identifi cation of the disease, timely prescription of appropriate treatment and prevention of severe complications

    Effect of gliprolines on lipid peroxidation rate in male rats’ immunocompetent organs under conditions of information stress

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    Introduction. The study of various aspects of the stress-reactivity of the body’s immune system, along with the search for correction tools characterized by immunoregulatory properties, is one of the most relevant areas of physiology and pharmacology. Currently, neuropeptides belonging to the group of glурrоlins (the registered drug “sеlаnk” and the new compounds Рro-Glу-Рro-Leu and Рro-Glу-Рro) are of particular interest in practical application as promising bioregulators, in particular their effects on the processes of free radical oxidation, as well as the ability to restore changes from the immune system, including those formed in response to stress.The aim of the study: was to study the effect of glурrоlins on the intensity of lipid peroxidation, catalase activity in the spleen and thymus of male rats under experimental information stress.Material and methods. The study was performed on white nonlinear male rats on which the model of information stress, based on the formation of behavior in animals in a multi-alternative food-producing maze, was reproduced for 20 days. The initial content of malondialdehyde, the rate of spontaneous and ascorbate-dependent lipid peroxidation were determined by standard spectrophotometric methods, and the activity of catalase in the homogenate of the thymus and spleen of experimental animals was evaluated.Results. Under the studied stress conditions, an increase in peroxidation processes was noted. Against the background of the introduction of sеlаnk, Рro-Glу-Рro and Рro-Glу-Рro-Leu, the suppression of the intensity of lipid peroxidation processes in the homogenates of the spleen and thymus tissue of male rats was established (a decrease in the initial level, the rate of spontaneous and ascorbate-dependent lipid peroxidation).Conclusions. Injection of neuropeptides belonging to the group of glyprolins (sеlаnk, Рro-Glу-Рro-Leu and Рro-Glу-Рro) under informational stress conditions contributes to the suppression of the intensity of lipid peroxidation processes, which indicates the stress-protective and immunocorrective effect of the studied substances

    Feasibility of study magnetic proximity effects in bilayer "superconductor/ferromagnet" using waveguide-enhanced Polarized Neutron Reflectometry

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    A resonant enhancement of the neutron standing waves is proposed to use in order to increase the magnetic neutron scattering from a "superconductor/ferromagnet"(S/F) bilayer. The model calculations show that usage of this effect allows to increase the magnetic scattering intensity by factor of hundreds. Aspects related to the growth procedure (order of deposition, roughness of the layers etc) as well as experimental conditions (resolution, polarization of the neutron beam, background etc) are also discussed. Collected experimental data for the S/F heterostructure Cu(32nm)/V(40nm)/Fe(1nm)/MgO confirmed the presence of a resonant 60-fold amplification of the magnetic scattering.Comment: The manuscript of the article submitted to Crysstalography Reports. 23 pages, 5 figure

    The use of ultrasonic cavitation for near-surface structuring of robust and low-cost AlNi catalysts for hydrogen production

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    Ultrasonically induced shock waves stimulate intensive interparticle collisions in suspensions and create large local temperature gradients in AlNi particles. These trigger phase transformations at the surface rather than in the particle interior. We show that ultrasonic processing is an effective approach for developing the desired compositional gradients in nm-thick interfacial regions of metal alloys and formation of effective catalysts toward the hydrogen evolution reaction

    The effect of the 7DL-7Ae#1L·7Ae#1S translocation on the productivity and quality of spring bread wheat grain

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    The 7DL-7Ae#1L·7Ae#1S translocation with the Lr29 gene attracts the attention of bread wheat breeders by its effectiveness against Puccinia triticina. However, its impact on useful agronomic traits has been little studied. In this report, the prebreeding value of 7DL-7Ae#1L·7Ae#1S was studied in analogue lines (ALs) of spring bread wheat cultivars Saratovskaya 68 and Saratovskaya 70 during 2019–2021. The presence of the Lr29 gene was conf irmed by using molecular marker Lr29F24. The ALs with the Lr29 gene were highly resistant to P. triticina against a natural epiphytotics background and in laboratory conditions. 7DL-7Ae#1L·7Ae#1S in Saratovskaya 68 ALs reduced grain productivity in all years of research. On average, the decrease was 35 and 42 %, or in absolute f igures 1163 and 1039 against 1802 kg/ha in the cultivar-recipient. In Saratovskaya 70 ALs, there was a decrease in grain yield in 2019 and 2020, and there were no differences in 2021. On average, the decrease was 18 and 32 %, or in absolute f igures 1101 and 912 against 1342 kg/ha in the cultivar-recipient. The analogues of both cultivars showed a signif icant decrease in the weight of 1000 grains, which ranged from 14 to 20 % for Saratovskaya 68 and 17–18 % for Saratovskaya 70. An increase in the period of germination-earing was noted only in Saratovskaya 68 lines, which averaged 1.3 days. ALs of Saratovskaya 70 had no differences in this trait. 7DL-7Ae#1L·7Ae#1S did not affect plant height and lodging resistance in all ALs. Studies of the bread-making quality in lines with 7DL-7Ae#1L·7Ae#1S revealed a signif icant increase in grain protein and gluten content. As for the effect on the alveograph indicators, there were differences between ALs of both cultivars. While Saratovskaya 68 ALs had a decrease in elasticity and in the ratio of dough tenacity to the extensibility, Saratovskaya 70 lines had an increase in these indicators. All lines increased the f lour strength and the loaves volume, but while Saratovskaya 68 ALs had an increased porosity rating, Saratovskaya 70 ALs had the same rating as the recipient

    МЕТОДИЧЕСКИЙ ПОДХОД К ОЦЕНКЕ СОСТОЯНИЯ ПРОЕКТОВ И ПРОГРАММ МЕЖРЕГИОНАЛЬНОГО ПРИГРАНИЧНОГО СОТРУДНИЧЕСТВА

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    The processes of assess interregional cross-border cooperation necessary to introduce modern methods to evaluate the effectiveness of programs and projects in cross-border region. The assessment’s method of projects and programs interregional cross-border is formulated, the basic principles of assessment and its criteria is formed, the identification of possible indicators for assessing the effectiveness of projects and programs interregional cross-border cooperation is determined in this paper.Для оценки процессов межрегионального приграничного сотрудничества необходимо внедрение современных методов, позволяющих оценить эффективность реализуемых программ и проектов на территории приграничных регионов. В настоящей статье представлены основы методики оценки состояния проектов и программ межрегионального приграничного сотрудничества, сформулированы основные принципы оценки, ее критерии, определены возможные показатели оценки эффективности проектов и программ межрегионального приграничного сотрудничества

    Distributed Computing Grid Experiences in CMS

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    The CMS experiment is currently developing a computing system capable of serving, processing and archiving the large number of events that will be generated when the CMS detector starts taking data. During 2004 CMS undertook a large scale data challenge to demonstrate the ability of the CMS computing system to cope with a sustained data-taking rate equivalent to 25% of startup rate. Its goals were: to run CMS event reconstruction at CERN for a sustained period at 25 Hz input rate; to distribute the data to several regional centers; and enable data access at those centers for analysis. Grid middleware was utilized to help complete all aspects of the challenge. To continue to provide scalable access from anywhere in the world to the data, CMS is developing a layer of software that uses Grid tools to gain access to data and resources, and that aims to provide physicists with a user friendly interface for submitting their analysis jobs. This paper describes the data challenge experience with Grid infrastructure and the current development of the CMS analysis system
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