499 research outputs found

    Genetic factors for development thrombophilia in pregnant

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    The results of studying the frequency of genetic polymorphism of receptor subunits platelet GP IIb/IIIa in 408 pregnant women. It was found that in women with thrombophilia normal variant of the gene occurred in 63.6%, heterozygous mutation - in 21%, homozygous mutation - in 15,2% of cases. In healthy women heterozygous mutation was revealed in 15,7%, normal genotype - in 84,3% and homozygous mutations was not detected at all. The connection between the occurrence of clinical manifestations of thrombophilia and the presence of hetero- and homozygous mutations of the subunits of platelet receptor GP IIb/IIIa was shown

    New limit on the mass of 9.4-keV solar axions emitted in an M1 transition in 83^{83}Kr nuclei

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    A search for resonant absorption of the solar axion by 83Kr^{83}\rm{Kr} nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings g3g01.69×106|g_3-g_0|\leq 1.69\times 10^{-6} allowed us to set the new upper limit on the hadronic axion mass of mA130m_{A}\leq 130 eV (95\% C.L.) with the generally accepted values SS=0.5 and zz=0.56.Comment: 5 pages, 2 figures, Proceedings of the 10th Patras Workshop on Axions, WIMPs and WISP 29 June - 4 July 2014, CERN, Geneva, Switzerlan

    Photoluminescence and its damping kinetics of nanoporous alumina m embranes formed in solutions of various carboxylic acids

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    The article is devoted to the study of the photoluminescence of carbon-containing anodic alumina obtained in various electrolytes based on carboxylic (tartaric and oxalic) acids. We studied the emission and excitation spectra of luminescence, as well as the PL decay of nanostructured anodic alumina membranes. It is shown that such membranes exhibit photoluminescence (excitation wavelength 330 nm) in the wavelength range 350-600 nm with a maximum at 460 nm. They have two PL centers with maxima at 440 and 490 nm and lifetimes of 0.2 and 4.0 ns, respectively. It is shown that the PL peak at 440 nm can be related to the emission of COO– - ions, and the peak at 490 nm can be related to the PL of defects in partially oxidized amorphous carbon

    Search for electron antineutrino interactions with the Borexino Counting Test Facility at Gran Sasso

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    Electron antineutrino interactions above the inverse beta decay energy of protons (E_\bar{\nu}_e>1.8) where looked for with the Borexino Counting Test Facility (CTF). One candidate event survived after rejection of background, which included muon-induced neutrons and random coincidences. An upper limit on the solar νˉe\bar{\nu}_{e} flux, assumed having the 8^8B solar neutrino energy spectrum, of 1.1×105\times10^{5} cm2^{-2}~s1^{-1} (90% C.L.) was set with a 7.8 ton ×\times year exposure. This upper limit corresponds to a solar neutrino transition probability, νeνˉe\nu_{e} \to \bar{\nu}_{e}, of 0.02 (90% C.L.). Predictions for antineutrino detection with Borexino, including geoneutrinos, are discussed on the basis of background measurements performed with the CTF.Comment: 10 pages, 9 figures, 5 table

    Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector

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    We report the measurement of electron neutrino elastic scattering from 8B solar neutrinos with 3 MeV energy threshold by the Borexino detector in Gran Sasso (Italy). The rate of solar neutrino-induced electron scattering events above this energy in Borexino is 0.217 +- 0.038 (stat) +- 0.008 (syst) cpd/100 t, which corresponds to the equivalent unoscillated flux of (2.4 +- 0.4 (stat) +- 0.1 (syst))x10^6 cm^-2 s^-1, in good agreement with measurements from SNO and SuperKamiokaNDE. Assuming the 8B neutrino flux predicted by the high metallicity Standard Solar Model, the average 8B neutrino survival probability above 3 MeV is measured to be 0.29+-0.10. The survival probabilities for 7Be and 8B neutrinos as measured by Borexino differ by 1.9 sigma. These results are consistent with the prediction of the MSW-LMA solution of a transition in the solar electron neutrino survival probability between the low energy vacuum-driven and the high-energy matter-enhanced solar neutrino oscillation regimes.Comment: 10 pages, 8 figures, 6 table

    Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

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    The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.Comment: Proceedings from NOW (Neutrino Oscillation Workshop) 201
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