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   4038篇
  免费   361篇
  国内免费   16篇
耳鼻咽喉   21篇
儿科学   168篇
妇产科学   61篇
基础医学   639篇
口腔科学   118篇
临床医学   498篇
内科学   808篇
皮肤病学   39篇
神经病学   369篇
特种医学   123篇
外科学   566篇
综合类   161篇
一般理论   4篇
预防医学   415篇
眼科学   20篇
药学   242篇
中国医学   2篇
肿瘤学   161篇
  2021年   38篇
  2020年   45篇
  2019年   58篇
  2018年   70篇
  2017年   45篇
  2016年   55篇
  2015年   65篇
  2014年   92篇
  2013年   161篇
  2012年   199篇
  2011年   219篇
  2010年   105篇
  2009年   111篇
  2008年   198篇
  2007年   206篇
  2006年   179篇
  2005年   179篇
  2004年   161篇
  2003年   157篇
  2002年   117篇
  2001年   116篇
  2000年   134篇
  1999年   131篇
  1998年   77篇
  1997年   53篇
  1996年   56篇
  1995年   36篇
  1994年   55篇
  1993年   52篇
  1992年   95篇
  1991年   84篇
  1990年   91篇
  1989年   77篇
  1988年   64篇
  1987年   69篇
  1986年   66篇
  1985年   72篇
  1984年   42篇
  1983年   58篇
  1982年   28篇
  1981年   31篇
  1980年   31篇
  1979年   41篇
  1978年   31篇
  1977年   38篇
  1976年   30篇
  1975年   29篇
  1974年   27篇
  1972年   32篇
  1971年   28篇
排序方式: 共有4415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.
Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive.  相似文献   
6.
7.
8.
9.
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   
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