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   1427篇
  免费   71篇
  2023年   3篇
  2022年   2篇
  2021年   10篇
  2020年   9篇
  2019年   18篇
  2018年   17篇
  2017年   25篇
  2016年   28篇
  2015年   42篇
  2014年   62篇
  2013年   78篇
  2012年   81篇
  2011年   102篇
  2010年   68篇
  2009年   55篇
  2008年   88篇
  2007年   99篇
  2006年   94篇
  2005年   76篇
  2004年   104篇
  2003年   103篇
  2002年   98篇
  2001年   9篇
  2000年   8篇
  1999年   22篇
  1998年   26篇
  1997年   12篇
  1996年   17篇
  1995年   8篇
  1994年   17篇
  1993年   11篇
  1992年   12篇
  1991年   11篇
  1990年   11篇
  1989年   12篇
  1988年   6篇
  1987年   2篇
  1986年   2篇
  1985年   6篇
  1984年   7篇
  1983年   2篇
  1982年   8篇
  1981年   4篇
  1980年   4篇
  1978年   5篇
  1977年   3篇
  1976年   6篇
  1975年   1篇
  1972年   1篇
  1970年   1篇
排序方式: 共有1498条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Seventeen Sse8387I linking clones isolated from the chromosome of Bacillus halodurans C-125 for the purpose of constructing a physical map were sequenced and analyzed by comparison with the BSORF database and the nonredundant protein databank. The orientations of Sse8387I or AscI linking clones serving to join adjacent fragments were determined by southern blot analysis using specific DNA probes. One-third of the open reading frames (ORFs) identified in the Sse8387I linking clones showed no significant similarity to any protein so far reported. The ORFs showing significant similarities to those of Bacillus subtilis were mapped in the chromosome of strain C-125, and the locations of the putative genes on the map were not well conserved between B. halodurans C-125 and B. subtilis. Received: March 26, 1999 / Accepted: April 27, 1999  相似文献   
5.
Transcutaneous pressure with pressure probes of arbitrary diameters have been commonly used for measuring the threshold and magnitude of muscle pain, yet this procedure lacks scientific validation. To examine the valid probe dimensions, we conducted physiological experiments using 34 human subjects. Pin-prick pain, pressure pain threshold (PPT) to pressure probes of various diameters, heat pain threshold, and electrical pain threshold of deep tissues were measured before and after application of surface lidocaine anesthesia to the skin surface over the brachioradial muscle in a double-blinded manner. The anesthesia neither affected PPT with larger probes (diameters: 1.6 and 15?mm) nor increased electric pain threshold of deep structures, whereas it diminished pain count in pin-prick test and PPT with a 1.0?mm diameter probe, suggesting that mechanical pain thresholds measured with 1.6 and 15?mm probes reflect the pain threshold of deep tissues, possibly muscle. Pain thresholds to heat did not change after application of the anesthesia. These results suggest that larger pressure probes can give a better estimation of muscular pain threshold.  相似文献   
6.
A strain of Mycoplasma hominis lacking a major membrane protein of 120 kDa was isolated from a Vero cell culture. This strain showed very slow growth rate and formed nipple-less colonies on agar medium.  相似文献   
7.
A paniculate fraction obtained from mesophyll cells of Zinniaelegans that were differentiating into tracheary elements exhibitedxylan synthase activity, catalyzing the transfer of MC-xylosefrom UDP-D-[U-14C]-xylose into 1,4-linked xylan. The activityincreased transiently at the same time as thickening of secondarycell walls occurred, a process that is accompanied by the depositionof cellulose, xylan and lignin. (Received August 3, 1990; Accepted December 6, 1990)  相似文献   
8.
Chemical optimization of the 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (THPP) scaffold was conducted with a focus on cellular potency while maintaining high selectivity against PI3K isoforms. Compound 11f was identified as a potent, highly selective and orally available PI3Kδ inhibitor. In addition, 11f exhibited efficacy in an in vivo antibody production model. The desirable drug-like properties and in vivo efficacy of 11f suggest its potential as a drug candidate for the treatment of autoimmune diseases and leukocyte malignancies.  相似文献   
9.
10.
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