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41.
We have previously reported multiple loci associated with prostate cancer susceptibility in a Japanese population using a genome-wide association study (GWAS). To identify additional prostate cancer susceptibility loci, we genotyped nine SNPs that were nominally associated with prostate cancer (P < 1 × 10(-4)) in our previous GWAS in three independent studies of prostate cancer in Japanese men (2,557 individuals with prostate cancer (cases) and 3,003 controls). In a meta-analysis of our previous GWAS and the replication studies, which included a total of 7,141 prostate cancer cases and 11,804 controls from a single ancestry group, three new loci reached genome-wide significance on chromosomes 11q12 (rs1938781; P = 1.10 × 10(-10); FAM111A-FAM111B), 10q26 (rs2252004; P = 1.98 × 10(-8)) and 3p11.2 (rs2055109; P = 3.94 × 10(-8)). We also found suggestive evidence of association at a previously reported prostate cancer susceptibility locus at 2p11 (rs2028898; P = 1.08 × 10(-7)). The identification of three new susceptibility loci should provide additional insight into the pathogenesis of prostate cancer and emphasizes the importance of conducting GWAS in diverse populations.  相似文献   
42.
3—氯丙基三甲氧基硅烷的合成   总被引:3,自引:0,他引:3  
以三氯硅烷与3-氯丙基丙烯为原料在氯铂酸复合催化剂催化下合成了3-氯丙基三氯硅烷,继而用醇醇解,合成了3-氯丙基三甲氧基硅烷,总收率80%。  相似文献   
43.
本文对单晶的生长条件进行了研究,用Brigdman方法成功地制备了R3Co单晶试料,为进一步研究其物性提供了必要的条件.  相似文献   
44.
我国低渗透气藏产气量在天然气总产量中所占比例越来越大,研究低渗透气藏的形成机理及形成过程是非常必要的。四川盆地上三叠统须家河组二段是重要的含气层位,但由于其储层具有非均质性强、且具低孔低渗的特点,不仅储层预测难度大,而且开发的效果也差。因此需要研究其形成过程,提高储层预测精度以改善开发效果。以储层岩石学特征、孔隙类型及分布特征、胶结物充填次序及充填时间等研究为基础,定时、定量地研究孔隙的整个演化历史,描述了孔隙在不同历史阶段的大小及变化原因,从而再现了储层形成历史,为下一步须二段气藏有效储层的预测与有效开发打下基础。  相似文献   
45.
Bico J  Roman B  Moulin L  Boudaoud A 《Nature》2004,432(7018):690
We investigated why wet hair clumps into bundles by dunking a model brush of parallel elastic lamellae into a perfectly wetting liquid. As the brush is withdrawn, pairs of bundles aggregate successively, forming complex hierarchical patterns that depend on a balance between capillary forces and the elasticity of the lamellae. This capillary-driven self-assembly of flexible structures, which occurs in the tarsi of insects and in biomimetic adhesives but which can also damage micro-electromechanical structures or carbon nanotube 'carpets', represents a new type of coalescence process.  相似文献   
46.
The best spectrographs are limited in stability by their calibration light source. Laser frequency combs are the ideal calibrators for astronomical spectrographs. They emit a spectrum of lines that are equally spaced in frequency and that are as accurate and stable as the atomic clock relative to which the comb is stabilized. Absolute calibration provides the radial velocity of an astronomical object relative to the observer (on Earth). For the detection of Earth-mass exoplanets in Earth-like orbits around solar-type stars, or of cosmic acceleration, the observable is a tiny velocity change of less than 10 cm s(-1), where the repeatability of the calibration--the variation in stability across observations--is important. Hitherto, only laboratory systems or spectrograph calibrations of limited performance have been demonstrated. Here we report the calibration of an astronomical spectrograph with a short-term Doppler shift repeatability of 2.5 cm s(-1), and use it to monitor the star HD 75289 and recompute the orbit of its planet. This repeatability should make it possible to detect Earth-like planets in the habitable zone of star or even to measure the cosmic acceleration directly.  相似文献   
47.
高压抗噪声干扰MOS栅驱动电路的设计   总被引:1,自引:0,他引:1  
设计了一种高压抗噪声干扰MOS栅驱动电路,能有效抑制开关转换过程中产生的dv/dt噪声,消除高压电路工作过程中可能出现的误触发,提高系统的稳定性和可靠性.采用共模反馈从而使电路结构简单,同时采用窄脉冲触发式控制降低了功耗.本电路可以集成在高压集成电路(HVIC)中.采用某公司高压600V0.5μm BCD工艺模型,通过Cadence仿真验证表明:本电路可有效滤除dv/dt噪声,被消除的dv/dt噪声最高可以达到60V/ns,同时被消除的失调噪声可以达到20%,保证了高压栅驱动电路稳定、可靠地工作.  相似文献   
48.
本文以矩形孔为例,给出了物体平面相对系统光轴倾斜时夫琅和费衍射场的理论计算。  相似文献   
49.
50.
The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.  相似文献   
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