23 research outputs found

    The observation of silicon nanocrystals in siloxene

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    This article discusses the observation of silicon nanocrystals in siloxene using high resolution transmission electron microscopy

    Association analysis of PON2 genetic variants with serum paraoxonase activity and systemic lupus erythematosus

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    <p>Abstract</p> <p>Background</p> <p>Low serum paraoxonase (PON) activity is associated with the risk of coronary artery disease, diabetes and systemic lupus erythematosus (SLE). Our prior studies have shown that the <it>PON1</it>/rs662 (p.Gln192Arg), <it>PON1</it>/rs854560 (p.Leu55Met), <it>PON3</it>/rs17884563 and <it>PON3</it>/rs740264 SNPs (single nucleotide polymorphisms) significantly affect serum PON activity. Since <it>PON1, PON2 </it>and <it>PON3 </it>share high degree of structural and functional properties, in this study, we examined the role of <it>PON2 </it>genetic variation on serum PON activity, risk of SLE and SLE-related clinical manifestations in a Caucasian case-control sample.</p> <p>Methods</p> <p><it>PON2 </it>SNPs were selected from HapMap and SeattleSNPs databases by including at least one tagSNP from each bin defined in these resources. A total of nineteen <it>PON2 </it>SNPs were successfully genotyped in 411 SLE cases and 511 healthy controls using pyrosequencing, restriction fragment length polymorphism (RFLP) or TaqMan allelic discrimination methods.</p> <p>Results</p> <p>Our pair-wise linkage disequilibrium (LD) analysis, using an <it>r</it><sup><it>2 </it></sup>cutoff of 0.7, identified 14 <it>PON2 </it>tagSNPs that captured all 19 <it>PON2 </it>variants in our sample, 12 of which were not in high LD with known <it>PON1 </it>and <it>PON3 </it>SNP modifiers of PON activity. Stepwise regression analysis of PON activity, including the known modifiers, identified five <it>PON2 </it>SNPs [rs6954345 (p.Ser311Cys), rs13306702, rs987539, rs11982486, and rs4729189; <it>P </it>= 0.005 to 2.1 × 10<sup>-6</sup>] that were significantly associated with PON activity. We found no association of <it>PON2 </it>SNPs with SLE risk but modest associations were observed with lupus nephritis (rs11981433, rs17876205, rs17876183) and immunologic disorder (rs11981433) in SLE patients (<it>P </it>= 0.013 to 0.042).</p> <p>Conclusions</p> <p>Our data indicate that <it>PON2 </it>genetic variants significantly affect variation in serum PON activity and have modest effects on risk of lupus nephritis and SLE-related immunologic disorder.</p

    Silicon Crystallite formation in Ion-Implanted Quartz

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    Rapid thermally annealed silicon‐implanted x‐cut α‐quartz samples have been examined by Rutherford backscattering and Raman microprobe spectroscopy. The data indicate that the silicon has diffused at 1200 °C to form a buried layer of crystallites of size 1–10 μm. The crystallites are preferentially oriented and under substantial stress
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