4,876 research outputs found

    The interaction of amyloid A beta(1-40) with lipid bilayers and ganglioside as studied by P-31 solid-state NMR

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    Amyloid P-peptide (A beta) is a major component of plaques in Alzheimer's disease, and formation of senile plaques has been suggested to originate fro m regions of neuronal membrane rich in gangliosides. We analyzed the mode of interaction of A beta with lipid bilayers by multinuclear NMR using P-31 nuclei. We found that A beta (1-40) strongly perturbed the bilayer structure of dimyristoylphosphatidylcholine (DMPQ, to form a non-lamellar phase (most likely micellar). The ganglioside GM1 potentiated the effect of A beta (1-40), as viewed from P-31 NMR. The difference of the isotropic peak intensity between DMPC/A beta and DMPC/GM1/A beta suggests a specific interaction between A beta and GM1. We show that in the DMPC/GM1/A beta system there are three lipid phases, namely a lamellar phase, a hexagonal phase and non-oriented lipids. The latter two phases are induced by the presence of the A beta peptide, and facilitated by GM1. 9) 2008 Elsevier Ireland Ltd. All rights reserved

    XMM-Newton Observation of the Northwest Radio Relic Region in Abell 3667

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    Abell 3667 is the archetype of a merging cluster with radio relics. The NW radio relic is the brightest cluster relic or halo known, and is believed to be due to a strong merger shock. We have observed the NW relic for 40 ksec of net XMM time. We observe a global decline of temperature across the relic from 6 to 1 keV, similar to the Suzaku results. Our new observations reveal a sharp change of both temperature and surface brightness near the position of the relic. The increased X-ray emission on the relic can be equivalently well described by either a thermal or nonthermal spectral model. The parameters of the thermal model are consistent with a Mach number M~2 shock and a shock speed of ~1200 km s^-1. The energy content of the relativistic particles in the radio relic can be explained if they are (re)-accelerated by the shock with an efficiency of ~0.2%. Comparing the limit on the inverse Compton X-ray emission with the measured radio synchrotron emission, we set a lower limit to the magnetic field in the relic of 3 muG. If the emission from the relic is non-thermal, this lower limit is in fact the required magnetic field.Comment: 11 pages, ApJ in pres

    Development of Uniform CdTe Pixel Detectors Based on Caltech ASIC

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    We have developed a large CdTe pixel detector with dimensions of 23.7 x 13.0 mm and a pixel size of 448 x 448 um^2. The detector is based on recent technologies of an uniform CdTe single crystal, a two-dimensional ASIC, and stud bump-bonding to connect pixel electrodes on the CdTe surface to the ASIC. Good spectra are obtained from 1051 pixels out of total 1056 pixels. When we operate the detector at -50 C, the energy resolution is 0.67 keV and 0.99 keV at 14 keV and 60 keV, respectively. Week-long stability of the detector is confirmed at operating temperatures of both -50 C and -20 C. The detector also shows high uniformity: the peak positions for all pixels agree to within 0.82%, and the average of the energy resolution is 1.04 keV at a temperature of -50 C. When we normalized the peak area by the total counts detected by each pixel, a variation of 2.1 % is obtained.Comment: 11pages, 17figures, accepted for publication in Proc. SPIE 200

    Observation of an energetic radiation burst from mountain-top thunderclouds

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    During thunderstorms on 2008 September 20, a simultaneous detection of gamma rays and electrons was made at a mountain observatory in Japan located 2770 m above sea level. Both emissions, lasting 90 seconds, were associated with thunderclouds rather than lightning. The photon spectrum, extending to 10 MeV, can be interpreted as consisting of bremsstrahlung gamma rays arriving from a source which is 60 - 130 m in distance at 90% confidence level. The observed electrons are likely to be dominated by a primary population escaping from an acceleration region in the clouds.Comment: 12 pages, 3 figures, accepted for publication in Physical Review Letter

    Neutrophilic dermatoses with acute myeloid leukemia associated with an increase of serum colony-stimulating factor

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    ArticleJOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY. 59(2)S10-S12(2008)journal articl

    MEASUREMENTS OF WINDING SPEED OF ROVING

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    ArticleJournal of the Faculty of Textile Science and Technology, Shinshu University. Ser. B, Engineering 14: 1-14(1979)departmental bulletin pape
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