410 research outputs found

    Experimental study of the vidicon system for information recording using the wide-gap spark chamber of gamma - telescope gamma-I

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    The development of the gamma ray telescope is investigated. The wide gap spark chambers, used to identify the gamma quanta and to determine the directions of their arrival, are examined. Two systems of information recording with the spark chambers photographic and vidicon system are compared

    Near-threshold collisional dynamics in the \u3ci\u3ee\u3csup\u3e−\u3c/sup\u3ee\u3csup\u3e+\u3c/sup\u3ep\u3c/i\u3e system

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    We study e+-H(n) and Ps(n)-p collisions near the three-body breakup threshold and thresholds for the charge-transfer processes.We show that classical trajectoryMonte Carlo (CTMC) simulations for the three-body breakup agree reasonably well in this energy region with quantum-mechanical convergent close-coupling (CCC) calculations even if the initial hydrogen atom or positronium atom is in the ground state. The threshold behavior of the three-body breakup cross section in e+-H(1s) and Ps(1s)-p collisions agrees with the Wannier law with Klar’s exponent and obeys the classical scaling laws, although some deviation from the Klar-Wannier behavior is observed in the CCC results. Below the threshold the agreement between CTMC and CCC disappears. In particular the CTMC method fails completely for the processes of H formation in Ps(1s)-p collisions and Ps formation in e+-H collisions well below the three-body breakup threshold. For higher initial states the CTMC results below the threshold improve substantially, in accordance with the correspondence principle. This is explained by comparing the quantum-mechanical threshold laws with the classical laws

    Antiproton collisions with excited positronium

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    We present results of calculations of several processes resulting from positronium (Ps) collisions with antiprotons: antihydrogen formation, Ps breakup, and nPs-changing collisions. Calculations utilize the quantum convergent close-coupling (CCC) method and the classical trajectory Monte Carlo (CTMC) method. We identify a region of Ps principal quantum numbers nPs and Ps energies where the classical description is valid and where the CCC calculations become computationally too expensive. This allows us to present the most complete and reliable set of cross sections in a broad range of nPs and initial orbital momentum quantum numbers lPs which are necessary for experiments with antihydrogen at CERN

    Analysis of hadron production in nucleus-nucleus interactions up to and out of kinematical limit of free NN-collisions in the frame of FRITIOF model

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    In the framework of the modified FRITIOF model, the inclusive spectra of the cumulative π0\pi ^0-, π\pi ^- -mesons and protons produced in the nucleus-nucleus interactions at 4.5 GeV/c/nucleon and 4.2 GeV/c/nucleon are calculated. It is shown that the model reproduces qualitatively, and in some cases quantitatively the main experimental regularities of π\pi-mesons production, and "soft" part of the proton spectra. According to the model the production of the cumulative particles is connected with the mechanism of the "soft" nucleon-nucleon interaction.Comment: 12 pages, 11 figure

    Structure and magnetic properties of LiNi1-xCoxPO4 magnetoelectrics with x = (0, 0.1, and 0.2)

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    We present the magnetic properties of LiNi1-xCoxPO4 magnetoelectrics, with x = (0-0.2), and their analysis of concentration dependences. Samples have been synthesized by a glycerol-nitrate method. To refine crystal structure X-ray diffraction measurements were carried out. Magnetic measurements were performed at the external magnetic field of 500 Oe over the temperature range (2-300) K. The neutron powder diffraction patterns of LiNi0.9Co0.1PO4 were recorded over temperature interval from 4.4 K up to 25 K. The partial doping in the LiNi1-xCoxPO4 magnetoelectrics the Ni ions for Co ions leads to a narrowing of the temperature interval where the incommensurate phase is established. © Published under licence by IOP Publishing Ltd.3.6121.2017/8.902.The work was supported by MES of RF (contract No. 3.6121.2017/8.9), and by Act 211 Government of RF (contract No. 02.A03.21.0006)

    Structure and magnetoelectric coupling of LiNi1-xCoxPO4 multiferroics

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    This work was supported by MES of RF (contract No. 3.6121.2017/8.9), Act 211 Government of RF (contract No. 02.A03.21.0006), and supported in part by FASO of Russia (theme “Flux” No. AAA-A18-118020190112-8). The equipment of the Ural Center for Shared Use “Modern nanotechnology” SNSM UrFU was used

    Tumor inflating lymphocytes. Purification, expanding and cytotoxicity analisys on primary tumor cultures

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    Background. Tumor Infiltrating Lymphocytes (TILs) is one of the most promising sources of autologous cytotoxic T-cells for adoptive immunotherapy, which has already shown high efficiency in the treatment of metastatic melanoma. However, the isolation of TILs from solid tumors is technically difficult. A suppressive tumor microenvironment, in particular, a high level of expression of check-point inhibitors PD-1 CTLA4, tissue hypoxia and other factors cause that T cells isolated from the tumor do not proliferate well and do not exhibit cytotoxic properties. Aims. In this study, we isolated TILs from surgical material obtained by resection of solid tumors (primary and metastatic adenocarcinomas of various localization, melanoma, glioblastoma), studied their population composition and developed protocols for the purification expanding, and activation of CD4+, CD8+ cytotoxic antitumor lymphocytes. Methods. An urgent task is the activation of TILs, turning off immunosuppressive mechanisms and increasing their antitumor cytotoxic activity. Various approaches are used for this: activation by a cocktail of cytokines and antibodies, editing the lymphocyte genome by knocking out suppressor genes or, conversely, transduction of activating genes, coincubation with feeder cells, etc. Cells were obtained from samples of resected tumors in 16 patients; in each case we obtain an autologous pair: the primary tumor culture and the TILs culture. Results. We could isolate viable lymphocytes in 100% of cases. Isolated TILs were successfully expanded in our specialized medium using various combinations of IL-2, IL-15, IL-21, IL-7, anti-CD3 and anti-CD28. Immunophenotyping showed that the obtained TILs are a heterogeneous mixture of CD4+, CD8+ cells containing populations of CD3+CD8+CD45+(CTL) CD3+CD4+CD45+ (T-helpers), CD4+CD25+CD127- (Т-regulatory cells), CD3-CD56+CD45+ (NK-cells), CD3+CD56+CD45+ (Т-NK-cells). The initial cultures of TILs were also characterized by a high level of PD1 expression, indicating their low antitumor cytotoxicity. Using different protocols of isolation, expansion, and activation, we obtained a cell preparation containing 80% of CD8+ PD-1- activated TILs in an amount sufficient for adoptive therapy (500106 or more). An in vitro study of the cytotoxicity of obtained TILs in primary cultures of homologous tumors using RTCA Icelligence showed high cytotoxicity, providing almost 100% tumor cell death. Conclusion. Our developed protocol for the production and activation of TILs can be recommended for the phase III clinical trials of adoptive immunotherapy of recurrent, highly metastatic solid tumors

    The study of the structure of anxiety in athletes

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    Objective: to study the structure of disorders caused by anxiety in athletes. Materials and methods: the objects of the first task of the research were different terminological definitions and classifications of anxiety disorders. Comparative analysis of the definitions and concepts used in psychology, physiology, sports medicine, theory and methodology of physical education has been carried out. The second task was to determine the leading factors characterizing the psychological status of athletes, and to give them the descriptive characteristics. A factor analysis was conducted on the results of testing 79 athletes of combat sports (34 men, 45 women) using the M Luscher color test and the integrative anxiety test by AP Bizyuk, LI Wasserman, BV Iovlev. Results: Luscher's test scores (total deviation from the autogenous rate, mental performance, vegetative coefficient) explained only 14.5% of the total variance. Simultaneously, the indicator of situational anxiety from Luscher's test was not included in any factor. The informativeness of more detailed integrative anxiety test was significantly higher: its indicators were included in 3 factors, explaining totally 49.5% of the total variance, as well as in the general factor, which explains 33% of the total variance. Conclusions: the emotional component (emotions which cause situational anxiety) contributes largely to the total anxiety level, some smaller contribution accounts for the social components (fear of condemnation, dependence on the opinions of others), finally, the personal anxiety contributes to it even less
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