24 research outputs found

    A new model for magnetoreception

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    Certain migratory birds can sense the earth's magnetic field. The nature of this process is not yet properly understood. Here we offer a simple explanation according to which birds literally `see' the local magnetic field: Our model relates the well-established radical pair hypothesis to the phenomenon of Haidinger's brush, a capacity to see the polarisation of light. This new picture explains recent surprising experimental data indicating long lifetimes for the radical pair. Moreover there is a clear evolutionary path toward this field sensing mechanism: it is an enhancement of a weak effect that may be present in many species.Comment: 8 pages, 5 figures, version of final published pape

    Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered

    The analysis of the dynamics in the incidence of respiratory diseases in Minsk population within the period of 2006-2014

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    METHODOLOGICAL APPROACHES TO EXPERT EVALUATION OF PRECLINICAL AND CLINICAL TRIALS OF HUMAN IMMUNOGLOBULIN PRODUCTS

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    The article considers the experience of Russian and leading foreign regulatory agencies in organisation and conduction of preclinical and clinical trials of human immunoglobulin products. The authors suggest a classification of human immunoglobulins and provide updated information on authorization of these products in Russia. The article summarizes methodological approaches, basic scientific principles and criteria relating to expert evaluation of preclinical and clinical trials of blood products. The authors further define the expert body’s requirements for data on preclinical and clinical trials of human normal immuniglobulins and human specific immunoglobulins for the prevention and/or treatment of infectious and non-infectious diseases which are submitted as part of applications for marketing authorization or marketing authorization variation. The article suggests programs of preclinical and clinical trials for human normal immunoglobulins and human specific immunoglobulins for the prevention and/or treatment of infectious and non-infectious diseases that are aligned with the Russian legislation and Eurasian Economic Union’s regulations on medicines circulation, and have been elaborated with respect to the guidelines of the European Medicines Agency

    Radiation damage effects in Y2_2SiO5_5:Ce scintillation crystals under Îł\gamma-quanta and 24 GeV protons

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    This work focuses on the study of changes in the optical transmission of Y 2 SiO 5 :Ce crystals caused by ionizing radiation from γ-quanta and high energy protons. Radioisotope content of proton-irradiated crystals, transmission and induced absorption spectra, and scintillation characteristics are measured after irradiation with protons. In contrast to crystals of heavy complex oxides, Y 2 SiO 5 :Ce crystals do not demonstrate significant deterioration of transmission in the luminescence range (400–600 nm) under irradiation. Such crystals can be considered as a material for construction of detecting cells of the calorimetric detectors at LHC with high luminosity. The feasibility of growing large crackless Y 2 SiO 5 :Ce crystals with a diameter up to 50 mm and length up to 250mm is demonstrated

    Studies on luminescence from a cerium-doped strontium stannate phosphor

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    WOS: 000353059000016PubMed ID: 25187514The crystal structure and morphology of Ce3+-doped SrSnO3 materials prepared using the solid-state reaction method were extensively characterized using experimental techniques. X-Ray diffraction results show that the cerium substitution of strontium does not change the structure of the strontium stannate. Raman spectroscopy was used to investigate the microstructures and lattice vibrations. Environmental scanning electron microscopy images showed that phosphors aggregate and their particles form irregular shapes. SrSnO3 exhibits an intense green emission with a broad band originating from the 5d(1)4f(1) transition of cerium. It was observed that, after exposure to beta-irradiation, the glow curve of this material has two broad thermoluminescence peaks, one centered at similar to 127 degrees C and the other at similar to 245 degrees C for a heating rate of 5 K/s. The kinetic parameters, which include the frequency factor and the activation energy of the material, were calculated using Chen's method, after beta-irradiation. The fading and reusability of the phosphor were also studied and it was found that the phosphor is suitable for radiation dosimetry. Copyright (c) 2014 John Wiley & Sons, Ltd
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