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   3001篇
  免费   326篇
  国内免费   236篇
  2024年   10篇
  2023年   96篇
  2022年   151篇
  2021年   153篇
  2020年   159篇
  2019年   201篇
  2018年   139篇
  2017年   122篇
  2016年   129篇
  2015年   140篇
  2014年   154篇
  2013年   282篇
  2012年   165篇
  2011年   160篇
  2010年   119篇
  2009年   166篇
  2008年   145篇
  2007年   195篇
  2006年   143篇
  2005年   101篇
  2004年   104篇
  2003年   71篇
  2002年   65篇
  2001年   47篇
  2000年   47篇
  1999年   33篇
  1998年   27篇
  1997年   22篇
  1996年   22篇
  1995年   17篇
  1994年   14篇
  1993年   13篇
  1992年   9篇
  1991年   14篇
  1990年   6篇
  1989年   12篇
  1988年   7篇
  1987年   13篇
  1986年   6篇
  1985年   11篇
  1984年   11篇
  1983年   12篇
  1982年   11篇
  1981年   9篇
  1980年   7篇
  1979年   8篇
  1978年   3篇
  1976年   3篇
  1975年   3篇
  1973年   3篇
排序方式: 共有3563条查询结果,搜索用时 15 毫秒
1.
Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians.  相似文献   
2.
《Cell reports》2020,30(1):61-68.e4
  1. Download : Download high-res image (250KB)
  2. Download : Download full-size image
  相似文献   
3.
4.
Orientation of optically nonlinear organic molecules inside sol-gel matrices upon application of an external D.C. electrical field is demonstrated for the first time. The quadratic nonlinear response of silicon oxide or transition metal oxide based gels containing organic molecules has been determined from Electric Field Induced Second Harmonic (EFISH) measurements. Large concentrations of Optically Nonlinear Organic Molecules (ONOM) have been either incorporated inside the macromolecular network or chemically bonded to the oxide backbone of the gels. These results demonstrate the feasibility of permanently poled doped sol-gel matrices. Moreover, EFISH measurements performed on organic molecules appear to be a useful tool for monitoring the changes occurring during sol-gel transformations.  相似文献   
5.
6.
7.
8.
9.
Proteins present in the seminal plasma of mammals are known to influence functions associated with ejaculated spermatozoa such as motility, capacitation, acrosome reaction and fertilising ability. The proteins isolated and characterised so far influence only one of the above functions of spermatozoa. Seminalplasmin, a protein isolated from the seminal plasma of bull is exceptional in that it influences many of the above spermatozoal functions. It is also a potent antimicrobial protein and capable of lysing microbial and mammalian cells. The physiological function of seminalplasmin as nature's own antifertility agent is discussed.  相似文献   
10.
Abstract  In this paper, we reported the differences in susceptibility to insecticides between adults and larvae of housefly, Musca domestica (L.), and the mechanisms for the differences. The larvae of housefly were much more tolerant to insecticides than the adults, and the tolerance ratio to cyhalothrin was as high as 205.5 for susceptible strain. Mechanism studies showed that higher GST activity was associated with higher insecticide tolerance in the larvae. The co-toxicity coefficient of the mixture of cyhalothrin and methylene dithiocyanate(4:1) on pyrehid-resistant houseflies was 188.  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