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   4229篇
  免费   365篇
  国内免费   20篇
耳鼻咽喉   22篇
儿科学   148篇
妇产科学   63篇
基础医学   650篇
口腔科学   121篇
临床医学   522篇
内科学   875篇
皮肤病学   43篇
神经病学   381篇
特种医学   221篇
外科学   575篇
综合类   111篇
一般理论   4篇
预防医学   413篇
眼科学   18篇
药学   275篇
中国医学   7篇
肿瘤学   165篇
  2021年   42篇
  2020年   46篇
  2019年   61篇
  2018年   70篇
  2017年   43篇
  2016年   74篇
  2015年   101篇
  2014年   95篇
  2013年   167篇
  2012年   206篇
  2011年   225篇
  2010年   114篇
  2009年   109篇
  2008年   202篇
  2007年   198篇
  2006年   178篇
  2005年   186篇
  2004年   158篇
  2003年   154篇
  2002年   120篇
  2001年   120篇
  2000年   133篇
  1999年   122篇
  1998年   63篇
  1997年   76篇
  1996年   66篇
  1995年   52篇
  1994年   56篇
  1993年   56篇
  1992年   95篇
  1991年   86篇
  1990年   97篇
  1989年   94篇
  1988年   73篇
  1987年   78篇
  1986年   75篇
  1985年   72篇
  1984年   44篇
  1983年   63篇
  1982年   34篇
  1981年   36篇
  1980年   31篇
  1979年   42篇
  1978年   30篇
  1977年   37篇
  1976年   30篇
  1975年   26篇
  1974年   27篇
  1972年   33篇
  1971年   28篇
排序方式: 共有4614条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Two postal questionnaire surveys were carried out among the adult population of Southampton aimed at clarifying the diagnostic criteria for asthma (study 1) and at testing the validity of symptoms so identified as diagnostic of bronchial hyper-reactivity (study 2). The questionnaires asked about respiratory symptoms and included three questions thought likely to disclose increased bronchial reactivity. Laboratory measurements on subsamples of respondents included spirometry and bronchial challenge with increasing doses of histamine till a concentration was reached provoking a fall of more than 20% (PC greater than 20) in forced expiratory volume in one second. In the first study no normal subject (that is, one who did not report shortness of breath or wheezing on the questionnaire) had a PC greater than 20 below 0.5 g/l. Of 51 subjects who reported shortness of breath or wheezing, or both, nine had a cluster of abnormalities consisting of one or more symptoms of bronchial irritability, nocturnal dyspnoea, and prolonged morning tightness together with PC greater than 20 values of 0.5 g/l or less. These symptoms in conjunction with a low PC greater than 20 were termed the bronchial irritability syndrome. In the second study bronchial challenge confirmed the close association of these symptoms with bronchial hyper-reactivity, all other subjects being less reactive to histamine. Only 27% of subjects with symptoms of the bronchial irritability syndrome had been diagnosed as asthmatic by their general practitioners. The bronchial irritability syndrome is a definable entity for epidemiological study and patient care.  相似文献   
5.
6.
7.
A case of acute cervical epidural abscess is presented. The use of intraoperative spinal sonography is discussed as a valuable adjunct in the evaluation and treatment of these uncommon lesions.  相似文献   
8.
9.
10.
Previous research found that the corpus callosum of male rats is larger than that of females; handling rats in infancy enhances this sex difference; and female rat pups, when handled in infancy and given 1 injection of testosterone propionate (TP) on Day 4 of life, will have callosa as large as those of males. In 2 experiments, male pups were castrated on Day 1 or received sham surgery; female pups were injected with TP on Day 4 or received an oil injection. Litters were handled or nonhandled. The previous finding that females, when handled and given TP in infancy, have a larger callosum was confirmed; however, a TP effect when administered to nonhandled females was not found. Because handling is known to cause a corticosterone release, these findings were interpreted as evidence of a developmental interaction between adrenal and gonadal hormones at the cortical level.  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