562 research outputs found

    The new approaches to problem of polymorbidity

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    High prevalence of polymorbidity in outpatient therapeutic practice calls for improvement of diagnostic approaches, in particular, the development of methods for its measurement and using the results for optimization the number of medical, rehabilitation, expert and prevention processes. The methodology of integrated evaluation of polymorbidity based on the principles of polyparametric analysis allows to stratify degree polymorbidity and significantly optimize the program of clinical supervision, treatment (including - assessing pharmacological load), prevention, rehabilitation, sanatorium selection, predicting the course and outcome of diseases, perform express-analysis of the degree of disability, cardiovascular risk in complex diagnostic and treatment intervention

    Giant Electroresistance in Ferroelectric Tunnel Junctions

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    The interplay between the electron transport in metal/ferroelectric/metal junctions with ultrathin ferroelectric barriers and the polarization state of a barrier is investigated. Using a model which takes into account screening of polarization charges in metallic electrodes and direct quantum tunneling across a ferroelectric barrier we calculate the change in the tunneling conductance associated with the polarization switching. We find the conductance change of a few orders of magnitude for metallic electrodes with significantly different screening lengths. This giant electroresistance effect is the consequence of a different potential profile seen by transport electrons for the two opposite polarization orientations.Comment: 4 page

    Anomalous behaviors of the charge and spin degrees of freedom in the CuO double chains of PrBa2_2Cu4_4O8_8

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    The density-matrix renormalization-group method is used to study the electronic states of a two-chain Hubbard model for CuO double chains of PrBa2_2Cu4_4O8_8. We show that the model at quarter filling has the charge ordered phases with stripe-type and in-line--type patterns in the parameter space, and in-between, there appears a wide region of vanishing charge gap; the latter phase is characteristic of either Tomonaga-Luttinger liquid or a metallic state with a spin gap. We argue that the low-energy electronic state of the CuO double chains of PrBa2_2Cu4_4O8_8 should be in the metallic state with a possibly small spin gap.Comment: REVTEX 4, 10 pages, 9 figures; submitted to PR

    Observation of nuclei with energies 8-30 MeV per nucleon in the Earth's magnetosphere at the altitudes 350 KM

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    Observations of the flux of nuclei with an energy of IO MeV per nucleon on the Salyut-7 Station in September 1984 are presented. The observed flux is smaller by a factor of 50 than the flux detected in May, 1981

    PSR B0329+54: Statistics of Substructure Discovered within the Scattering Disk on RadioAstron Baselines of up to 235,000 km

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    We discovered fine-scale structure within the scattering disk of PSR B0329+54 in observations with the RadioAstron ground-space radio interferometer. Here, we describe this phenomenon, characterize it with averages and correlation functions, and interpret it as the result of decorrelation of the impulse-response function of interstellar scattering between the widely-separated antennas. This instrument included the 10-m Space Radio Telescope, the 110-m Green Bank Telescope, the 14x25-m Westerbork Synthesis Radio Telescope, and the 64-m Kalyazin Radio Telescope. The observations were performed at 324 MHz, on baselines of up to 235,000 km in November 2012 and January 2014. In the delay domain, on long baselines the interferometric visibility consists of many discrete spikes within a limited range of delays. On short baselines it consists of a sharp spike surrounded by lower spikes. The average envelope of correlations of the visibility function show two exponential scales, with characteristic delays of τ1=4.1±0.3 μs\tau_1=4.1\pm 0.3\ \mu{\rm s} and τ2=23±3 μs\tau_2=23\pm 3\ \mu{\rm s}, indicating the presence of two scales of scattering in the interstellar medium. These two scales are present in the pulse-broadening function. The longer scale contains 0.38 times the scattered power of the shorter one. We suggest that the longer tail arises from highly-scattered paths, possibly from anisotropic scattering or from substructure at large angles.Comment: 15 pages, 6 figures, 3 tables; accepted by Astrophysical journa

    Lie group analysis for multi-scale plasma dynamics

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    An application of approximate transformation groups to study dynamics of a system with distinct time scales is discussed. The utilization of the Krylov-Bogoliubov-Mitropolsky method of averaging to find solutions of the Lie equations is considered. Physical illustrations from the plasma kinetic theory demonstrate the potentialities of the suggested approach. Several examples of invariant solutions for the system of the Vlasov-Maxwell equations for the two-component (electron-ion) plasma are presented.Comment: Latex, 15 pages, 7 figure. This is an enlarged contribution to Journal of Nonlinear Mathematical Physics v.18, Suppl. 1 (2011) p.163-175 with modest stylistic corrections introduced mainly in the third Sectio

    Anomalous and Spin Hall Effects in a Magnetic Tunnel Junction with Rashba Spin-Orbit Coupling

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    Anomalous and spin Hall effects are investigated theoretically for a magnetic tunnel junction where the applied voltage produces a Rashba spin-or bit coupling within the tunneling barrier layer. The ferromagnetic electrodes are the source of the spin-polarized current. The tunneling electrons experience a spin-orbit coupling inside the barrier due to the applied electrical field. Charge and spin Hall currents are calculated as functions of the position inside the barrier and the angle between the magnetizations of the electrodes. We find that both charge and spin Hall currents are located inside the barrier near the in terfaces. The dependence of the currents on magnetic configuration of the magnetic tunnel junction makes possible the manipulation by the Hall currents via rotation of the magnetization of the electrodes.Comment: 10 pages, 4 figure
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