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   713455篇
  免费   49176篇
  国内免费   1335篇
耳鼻咽喉   9376篇
儿科学   23452篇
妇产科学   17702篇
基础医学   111423篇
口腔科学   20126篇
临床医学   64205篇
内科学   136378篇
皮肤病学   16311篇
神经病学   49847篇
特种医学   25988篇
外国民族医学   76篇
外科学   105743篇
综合类   14854篇
现状与发展   2篇
一般理论   160篇
预防医学   51650篇
眼科学   16408篇
药学   54429篇
  3篇
中国医学   2368篇
肿瘤学   43465篇
  2021年   5589篇
  2018年   7974篇
  2017年   6206篇
  2016年   6956篇
  2015年   7689篇
  2014年   10430篇
  2013年   15600篇
  2012年   20760篇
  2011年   21815篇
  2010年   12888篇
  2009年   12088篇
  2008年   20272篇
  2007年   21833篇
  2006年   22244篇
  2005年   20809篇
  2004年   20351篇
  2003年   19275篇
  2002年   18841篇
  2001年   36587篇
  2000年   37159篇
  1999年   30598篇
  1998年   7988篇
  1997年   6740篇
  1996年   7032篇
  1995年   6710篇
  1994年   6166篇
  1993年   5646篇
  1992年   23154篇
  1991年   23090篇
  1990年   22484篇
  1989年   22253篇
  1988年   20191篇
  1987年   19559篇
  1986年   18578篇
  1985年   17445篇
  1984年   12776篇
  1983年   10812篇
  1982年   5958篇
  1979年   11590篇
  1978年   8167篇
  1977年   6882篇
  1976年   6621篇
  1975年   7319篇
  1974年   8529篇
  1973年   8160篇
  1972年   7690篇
  1971年   7168篇
  1970年   6909篇
  1969年   6341篇
  1968年   5809篇
排序方式: 共有10000条查询结果,搜索用时 15 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