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   6998篇
  免费   875篇
  国内免费   5篇
  2021年   85篇
  2019年   78篇
  2018年   85篇
  2017年   75篇
  2016年   113篇
  2015年   178篇
  2014年   236篇
  2013年   296篇
  2012年   345篇
  2011年   349篇
  2010年   212篇
  2009年   172篇
  2008年   284篇
  2007年   278篇
  2006年   264篇
  2005年   252篇
  2004年   268篇
  2003年   256篇
  2002年   243篇
  2001年   187篇
  2000年   212篇
  1999年   192篇
  1998年   100篇
  1997年   77篇
  1996年   94篇
  1995年   85篇
  1994年   83篇
  1993年   63篇
  1992年   156篇
  1991年   161篇
  1990年   142篇
  1989年   129篇
  1988年   136篇
  1987年   138篇
  1986年   113篇
  1985年   131篇
  1984年   109篇
  1983年   92篇
  1982年   67篇
  1981年   57篇
  1979年   92篇
  1978年   58篇
  1977年   69篇
  1976年   58篇
  1975年   65篇
  1974年   89篇
  1973年   79篇
  1972年   64篇
  1968年   61篇
  1967年   55篇
排序方式: 共有7878条查询结果,搜索用时 36 毫秒
1.
2.
3.
The dose of intravenous diazepam required for sedation was estimated in a series of 78 patients aged 17-85 years given the drug for dental and endoscopic procedures. Multiple regression analysis showed a significant correlation (r = 0.71; p less than 0.001) between dose and age, body weight, the taking of regular sedation, and the taking of more than 40 g alcohol daily, but there were no differences in the doses required between men and women, smokers and non-smokers, inpatients and outpatients, or dental and endoscopy patients. Patients aged 80 required an average dose of 10 mg and patients aged 20 an average dose of 30 mg, and the dose required was much higher in those receiving regular sedation or having a high alcohol intake. Plasma total and free diazepam concentrations were measured in the second half of the series of patients (n = 37). Plasma concentrations required for sedation fell twofold to threefold between the ages of 20 and 80 and were significantly higher in those taking regular sedation or alcohol. Differences in the acute response to diazepam appeared to be due to differences in the sensitivity of the central nervous system (pharmacodynamic tolerance) rather than to differences in pharmacokinetic factors.  相似文献   
4.
5.
6.
7.
8.
Comparative mapping studies of X-linked genes in mammals have provided insights into the evolution of the X chromosome. Many reptiles including the American alligator, Alligator mississippiensis, do not appear to possess heteromorphic sex chromosomes, and sex is determined by the incubation temperature of the egg during embryonic development. Mapping of homologues of mammalian X-linked genes in reptiles could lead to a greater understanding of the evolution of vertebrate sex chromosomes. One of the genes used in the mammalian mapping studies was ZFX, an X-linked copy of the human ZFY gene which was originally isolated as a candidate for the mammalian testis-determining factor (TDF). ZFX is X-linked in eutherians, but maps to two autosomal locations in marsupials and monotremes, close to other genes associated with the eutherian X. The alligator homologue of the ZFY/ZFX genes, Zfc, has been isolated and described previously. A detailed karyotype of A. mississippiensis is presented, together with chromosomal in situ hybridisation data localising the Zfc gene to chromosome 3. Further chromosomal mapping studies using eutherian X-linked genes may reveal conserved chromosomal regions in the alligator that have become part of the eutherian X chromosome during evolution.  相似文献   
9.
10.
  1. Download : Download high-res image (147KB)
  2. Download : Download full-size image
Highlights
  • •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
  • •Using patient derived xenograft (PDX) tumors can overcome this limitation.
  • •The large PDX HLA peptidomes expand significantly those of the original biopsies.
  • •The HLA peptidomes of the PDX tumors included many tumor antigens.
  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