105 research outputs found

    Efficacy of cimetidin in the prevention of ulcer formation in the stomach during immobilization stress

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    The effect of stress on the formation of ulcers in the mucous membrane of the stomach, the increase in cyclic adenosine monophosphate level in the gastric tissues, and parietal cell structure alteration. Use of cimetidin prevents these effect

    Thermal radiation and near-field energy density of thin metallic films

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    We study the properties of thermal radiation emitted by a thin dielectric slab, employing the framework of macroscopic fluctuational electrodynamics. Particular emphasis is given to the analytical construction of the required dyadic Green's functions. Based on these, general expressions are derived for both the system's Poynting vector, describing the intensity of propagating radiation, and its energy density, containing contributions from non-propagating modes which dominate the near-field regime. An extensive discussion is then given for thin metal films. It is shown that the radiative intensity is maximized for a certain film thickness, due to Fabry-Perot-like multiple reflections inside the film. The dependence of the near-field energy density on the distance from the film's surface is governed by an interplay of several length scales, and characterized by different exponents in different regimes. In particular, this energy density remains finite even for arbitrarily thin films. This unexpected feature is associated with the film's low-frequency surface plasmon polariton. Our results also serve as reference for current near-field experiments which search for deviations from the macroscopic approach

    Shape-dependence of near-field heat transfer between a spheroidal nanoparticle and a flat surface

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    We study the radiative heat transfer between a spheroidal metallic nanoparticle and a planar metallic sample for near- and far-field distances. In particular, we investigate the shape dependence of the heat transfer in the near-field regime. In comparison with spherical particles, the heat transfer typically varies by factors between 1/2 and 2 when the particle is deformed such that its volume is kept constant. These estimates help to quantify the deviation of the actual heat transfer recorded by a near-field scanning thermal microscope from the value provided by a dipole model which assumes a perfectly spherical sensor

    Thermal heat radiation, near-field energy density and near-field radiative heat transfer of coated materials

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    We investigate the thermal radiation and thermal near-field energy density of a metal-coated semi-infinite body for different substrates. We show that the surface polariton coupling within the metal coating leads to an enhancement of the TM-mode part of the thermal near-field energy density when a polar substrate is used. In this case the result obtained for a free standing metal film is retrieved. In contrast, in the case of a metal substrate there is no enhancement in the TM-mode part, as can also be explained within the framework of surface plasmon coupling within the coating. Finally, we discuss the influence of the enhanced thermal energy density on the near-field radiative heat transfer between a simple semi-infinite and a coated semi-infinite body for different material combinations

    Dissipative Van der Waals interaction between a small particle and a metal surface

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    We use a general theory of the fluctuating electromagnetic field to calculate the friction force acting on a small neutral particle, e.g., a physisorbed molecule, or a nanoscale object with arbitrary dispersive and absorptive dielectric properties, moving near a metal surface. We consider the dependence of the electromagnetic friction on the temperature TT, the separation dd, and discuss the role of screening, non-local and retardation effects. We find that for high resistivity materials, the dissipative van der Waals interaction can be an important mechanism of vibrational energy relaxation of physisorbed molecules, and friction for microscopic solids. Several controversial topics related to electromagnetic dissipative shear stress is considered. The problem of local heating of the surface by an STM tip is also briefly commented on.Comment: 11 pages, No figure

    Magnetic phase diagram and transport properties of FeGe_2

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    We have used resistivity measurements to study the magnetic phase diagram of the itinerant antiferromagnet FeGe_2 in the temperature range from 0.3->300 K in magnetic fields up to 16 T. In contrast to theoretical predictions, the incommensurate spin density wave phase is found to be stable at least up to 16 T, with an estimated critical field \mu _0H_c of ~ 30 T. We have also studied the low temperature magnetoresistance in the [100], [110], and [001] directions. The transverse magnetoresistance is well described by a power law for magnetic fields above 1 T with no saturation observed at high fields. We discuss our results in terms of the magnetic structure and the calculated electronic bandstructure of FeGe_2. We have also observed, for the first time in this compound, Shubnikov-de Haas oscillations in the transverse magnetoresistance with a frequency of 190 +- 10 T for a magnetic field along [001].Comment: 13 pages, RevTeX, 7 postscript figures, to appear in Journal of Physics: Condensed Matte

    ВНУТРИПОЛОСТНАЯ ТЕРАПИЯ ОЗОНИРОВАННЫМ АНТИСЕПТИЧЕСКИМ РАСТВОРОМ В КОМПЛЕКСНОМ ЛЕЧЕНИИ ПАЦИЕНТОВ С ИНФИЦИРОВАННЫМИ ПОЛОСТНЫМИ ОБРАЗОВАНИЯМИ ПЕЧЕНИ

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    Application   in  the   treatment of  patients  with  infected  cavitary  formations  liver intracavitary therapy ozonated antiseptic allowed  significantly  speed  up the  recovery  of liver function, reduce  the  time of hospital  treatment, to accelerate the  elimination  of the abscess  cavity.Применение в лечении у пациентов с инфицированными полостными образованиями печени внутриполостной терапии озонированным антисептическим раствором позволило достоверно ускорить  восстановление функции печени,  уменьшить сроки стационарного лечения, ускорить ликвидацию полости абсцесса
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