首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   982篇
  免费   10篇
  国内免费   34篇
系统科学   20篇
丛书文集   2篇
教育与普及   3篇
理论与方法论   12篇
现状及发展   206篇
研究方法   131篇
综合类   626篇
自然研究   26篇
  2021年   4篇
  2020年   5篇
  2019年   5篇
  2018年   14篇
  2017年   12篇
  2016年   8篇
  2015年   13篇
  2014年   18篇
  2013年   18篇
  2012年   67篇
  2011年   95篇
  2010年   37篇
  2009年   25篇
  2008年   52篇
  2007年   66篇
  2006年   52篇
  2005年   63篇
  2004年   39篇
  2003年   64篇
  2002年   53篇
  2001年   40篇
  2000年   42篇
  1999年   20篇
  1996年   4篇
  1992年   10篇
  1991年   7篇
  1990年   4篇
  1989年   10篇
  1988年   9篇
  1987年   9篇
  1986年   5篇
  1985年   9篇
  1982年   6篇
  1981年   7篇
  1980年   8篇
  1979年   8篇
  1978年   7篇
  1977年   10篇
  1976年   5篇
  1975年   9篇
  1974年   5篇
  1973年   9篇
  1972年   3篇
  1971年   9篇
  1970年   9篇
  1969年   7篇
  1968年   5篇
  1967年   7篇
  1966年   5篇
  1965年   7篇
排序方式: 共有1026条查询结果,搜索用时 15 毫秒
51.
A combined genome-wide association and linkage study was used to identify loci causing variation in cystic fibrosis lung disease severity. We identified a significant association (P = 3.34 × 10(-8)) near EHF and APIP (chr11p13) in p.Phe508del homozygotes (n = 1,978). The association replicated in p.Phe508del homozygotes (P = 0.006) from a separate family based study (n = 557), with P = 1.49 × 10(-9) for the three-study joint meta-analysis. Linkage analysis of 486 sibling pairs from the family based study identified a significant quantitative trait locus on chromosome 20q13.2 (log(10) odds = 5.03). Our findings provide insight into the causes of variation in lung disease severity in cystic fibrosis and suggest new therapeutic targets for this life-limiting disorder.  相似文献   
52.
53.
Autosomal dominant polycystic liver disease results from mutations in PRKCSH or SEC63. The respective gene products, glucosidase IIβ and SEC63p, function in protein translocation and quality control pathways in the endoplasmic reticulum. Here we show that glucosidase IIβ and Sec63p are required in mice for adequate expression of a functional complex of the polycystic kidney disease gene products, polycystin-1 and polycystin-2. We find that polycystin-1 is the rate-limiting component of this complex and that there is a dose-response relationship between cystic dilation and levels of functional polycystin-1 following mutation of Prkcsh or Sec63. Reduced expression of polycystin-1 also serves to sensitize the kidney to cyst formation resulting from mutations in Pkhd1, the recessive polycystic kidney disease gene. Finally, we show that proteasome inhibition increases steady-state levels of polycystin-1 in cells lacking glucosidase IIβ and that treatment with a proteasome inhibitor reduces cystic disease in orthologous gene models of human autosomal dominant polycystic liver disease.  相似文献   
54.
55.
56.
1 Results Bimetallic particles in the nanometer size range are of substantial interest due to their vast applications in catalysis[1].The synthesis of bimetallic nanoparticles with definite size with a well-control over their nanostructure remains a challenging problem.Thus there exists a great demand for both synthesis and atomic level characterization of nanostructure of bimetallic nanoparticles (NPs).With the recent advent of high-intensity tunable sources of X-rays,now available at synchrotron radia...  相似文献   
57.
A model is developed for convex-set valued data,which are the Minkowski sum of aconvex parameter set and a convex noise set.This model is generalized to include location and scaleparameters.A further generalization results in a model for convex sets which is analogous to aone-way analysis of variance models.In each case,estimators of the parameters are given which,under certain conditions,are shown to be consistent.Data generated from the model and theestimators are studied.An outlier detection method is examined.  相似文献   
58.
New use of BCG for recombinant vaccines   总被引:147,自引:0,他引:147  
BCG, a live attenuated tubercle bacillus, is the most widely used vaccine in the world and is also a useful vaccine vehicle for delivering protective antigens of multiple pathogens. Extrachromosomal and integrative expression vectors carrying the regulatory sequences for major BCG heat-shock proteins have been developed to allow expression of foreign antigens in BCG. These recombinant BCG strains can elicit long-lasting humoral and cellular immune responses to foreign antigens in mice.  相似文献   
59.
60.
Absence of gamma-globulin receptors on mouse plasmacytoma cells   总被引:6,自引:0,他引:6  
F Paraskevas  S T Lee  L G Israels 《Nature》1970,227(5256):395-397
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号