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   706436篇
  免费   48932篇
  国内免费   1308篇
耳鼻咽喉   9167篇
儿科学   23279篇
妇产科学   17618篇
基础医学   110481篇
口腔科学   19957篇
临床医学   63898篇
内科学   134445篇
皮肤病学   16181篇
神经病学   49474篇
特种医学   25761篇
外国民族医学   76篇
外科学   104529篇
综合类   14821篇
现状与发展   2篇
一般理论   160篇
预防医学   51448篇
眼科学   16324篇
药学   53997篇
  3篇
中国医学   2362篇
肿瘤学   42693篇
  2021年   5469篇
  2018年   7899篇
  2017年   6137篇
  2016年   6841篇
  2015年   7574篇
  2014年   10279篇
  2013年   15420篇
  2012年   20538篇
  2011年   21563篇
  2010年   12743篇
  2009年   11945篇
  2008年   20021篇
  2007年   21541篇
  2006年   21942篇
  2005年   20461篇
  2004年   20018篇
  2003年   18967篇
  2002年   18471篇
  2001年   36325篇
  2000年   36895篇
  1999年   30381篇
  1998年   7880篇
  1997年   6663篇
  1996年   6973篇
  1995年   6629篇
  1994年   6097篇
  1993年   5590篇
  1992年   22969篇
  1991年   22927篇
  1990年   22310篇
  1989年   22076篇
  1988年   20037篇
  1987年   19418篇
  1986年   18467篇
  1985年   17306篇
  1984年   12697篇
  1983年   10741篇
  1982年   5921篇
  1979年   11518篇
  1978年   8128篇
  1977年   6832篇
  1976年   6594篇
  1975年   7268篇
  1974年   8498篇
  1973年   8142篇
  1972年   7659篇
  1971年   7127篇
  1970年   6877篇
  1969年   6306篇
  1968年   5780篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males.  相似文献   
32.
33.
34.
BACKGROUND: Arterial hypertension and postmenopausal reduction of estrogen levels may be involved in modifications of the stiffness of large arteries. OBJECTIVES: To evaluate the pulse-wave velocity (PWV) and indirectly the arterial stiffness in hypertensive postmenopausal women submitted to hormone therapy with estradiol alone or combined with norethisterone acetate. SUBJECTS: Forty-five hypertensive postmenopausal women were double-blindly, randomly assigned to three arms of treatment: placebo (group I); estradiol 2 mg/day (group II); or estradiol 2 mg/day and norethisterone acetate 1 mg/day (group III). METHODS: Arterial stiffness was assessed from PWV measurements of the common carotid and femoral arteries (CF-PWV) and the common carotid and radial arteries (CR-PWV) obtained using the automatic Complior(R) device, taken at baseline and after 12 weeks of treatment. RESULTS: After the 12-week treatment, values of CF-PWV and CR-PWV were not significantly different (p = 0.910 and p = 0.736, respectively) among the groups. Systolic blood pressure showed a positive correlation with CF-PWV in groups II and III (p = 0.02 and p < 0.001, respectively). CONCLUSIONS: PWV and arterial stiffness in postmenopausal hypertensive women did not reduce over a 12-week treatment with estradiol alone compared with the same period of treatment with estradiol combined with norethisterone acetate.  相似文献   
35.
36.
A true comparison of long-term medical and surgical treatment in gastro-oesophageal reflux disease (GORD) is impossible as few studies have been carried out with adequate randomisation of the patients and long-term evaluation of quality of life. In general the control of the reflux symptoms is roughly equal with medical and surgical treatment. However, surgery can cause other symptoms such as dysphagia or non-specific epigastric discomfort or pain in some patients, which reduces the overall efficacy in controlling the symptoms. Based on a cost utility analysis, Heudebert et al. came to the conclusion that medical treatment was their preferred strategy for most patients with severe erosive oesophagitis.  相似文献   
37.
38.
39.
Acute renal failure (ARF) developed in a 7-week-old infant due to bilateral candidal bezoars (fungal balls) causing obstruction at the pelviureteric junction. The baby was born at term with an appropriate birthweight, and had been treated with broad-spectrum antibiotics for respiratory distress and septicemia during the 1st week of life. Recovery from ARF followed renal decompression with bilateral nephrostomy tube placement and parenteral administration of amphotericin B and 5-flucytosine. Received August 21, 1996; received in revised form and accepted January 3, 1997  相似文献   
40.
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