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   1653篇
  免费   79篇
  国内免费   6篇
耳鼻咽喉   2篇
儿科学   57篇
妇产科学   12篇
基础医学   238篇
口腔科学   45篇
临床医学   111篇
内科学   286篇
皮肤病学   23篇
神经病学   183篇
特种医学   153篇
外科学   256篇
综合类   67篇
预防医学   60篇
眼科学   19篇
药学   109篇
中国医学   10篇
肿瘤学   107篇
  2022年   21篇
  2021年   39篇
  2020年   24篇
  2019年   28篇
  2018年   41篇
  2017年   32篇
  2016年   34篇
  2015年   41篇
  2014年   48篇
  2013年   69篇
  2012年   96篇
  2011年   103篇
  2010年   73篇
  2009年   56篇
  2008年   101篇
  2007年   101篇
  2006年   56篇
  2005年   61篇
  2004年   55篇
  2003年   53篇
  2002年   54篇
  2001年   27篇
  2000年   29篇
  1999年   43篇
  1998年   27篇
  1997年   26篇
  1996年   23篇
  1995年   21篇
  1994年   19篇
  1993年   21篇
  1992年   17篇
  1991年   19篇
  1990年   32篇
  1989年   30篇
  1988年   24篇
  1987年   19篇
  1986年   24篇
  1985年   21篇
  1984年   18篇
  1982年   8篇
  1981年   8篇
  1980年   10篇
  1978年   7篇
  1976年   5篇
  1975年   7篇
  1973年   5篇
  1972年   7篇
  1971年   8篇
  1969年   5篇
  1968年   5篇
排序方式: 共有1738条查询结果,搜索用时 31 毫秒
1.
2.
3.
Evaluation of an on-line patient exposure meter in neuroradiology   总被引:1,自引:0,他引:1  
  相似文献   
4.
人体液中喷布洛尔及其代谢物的GC/MS分析   总被引:1,自引:0,他引:1  
用气相色谱一质谱联用(GC-MSD)系统分析方法检出了人尿中喷布洛尔的6个羟化代谢物,用Scp-Pak柱提取的方法检出了人血浆中的原型药物。并从分子结构上对此药物的代谢途径进行了研究。尿中提取和血中提取的回收率分别为90.83.%和85.88%,Gc-MSD的检测限为5pg。本方法适用于运动员兴奋剂的系统检查。  相似文献   
5.
6.
7.
Pulmonary function in healthy young adult Indians in Madras.   总被引:2,自引:0,他引:2       下载免费PDF全文
Forced vital capacity, forced expiratory volume in one second, functional residual capacity, residual volume, total lung capacity, and single breath diffusing capacity measurements (effective alveolar volume, carbon monoxide transfer factor, and transfer coefficient) were measured in 247 young healthy adults (130 male, 117 female) aged 15-40 years living in Madras. Subjects were of Dravidian stock, living at sea level with rice as their staple diet. Regression equations were derived for men and women for predicting normal pulmonary function for young adults in South India. The values were similar to those reported for subjects from Western India and lower than those reported for North Indians and caucasians.  相似文献   
8.
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.   相似文献   
9.
10.
Headache following lumbar puncture is a well known and well described complication. Various manoeuvres have been tried to prevent post lumbar puncture headache--the commonest being bed rest for 4 to 24 hours following lumbar puncture, though its value is questionable. Randomised controlled clinical trial was done to evaluate the effect of 24 hours bed rest on the incidence and severity of post lumbar puncture headaches. Two hundred and eight patients were randomly allocated to either the ambulant or the bed rest group. Patients were interviewed by a single investigator on days 0, 1, 2 and 7 about the presence and nature of headache. Other relevant clinical and laboratory data pertaining to the lumbar puncture was collected. The overall incidence of post lumbar puncture headache was 17%; 15% in the ambulant and 18% in the bed rest group. Of the patients who had headaches, severe headache was observed in 57% in the ambulant and 12% in the bed rest group (p = 0.02). Other variables did not alter the outcome of headaches. Bed rest does not appear to alter the incidence of post lumbar puncture headaches, but reduces the severity in those who get headaches, after a lumbar puncture.  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