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   707525篇
  免费   48952篇
  国内免费   1314篇
耳鼻咽喉   9176篇
儿科学   23283篇
妇产科学   17646篇
基础医学   110628篇
口腔科学   19980篇
临床医学   63882篇
内科学   134848篇
皮肤病学   16175篇
神经病学   49523篇
特种医学   25791篇
外国民族医学   76篇
外科学   104790篇
综合类   14826篇
现状与发展   2篇
一般理论   160篇
预防医学   51445篇
眼科学   16331篇
药学   54029篇
  3篇
中国医学   2369篇
肿瘤学   42828篇
  2021年   5466篇
  2018年   7884篇
  2017年   6129篇
  2016年   6847篇
  2015年   7563篇
  2014年   10299篇
  2013年   15425篇
  2012年   20570篇
  2011年   21549篇
  2010年   12764篇
  2009年   11966篇
  2008年   20068篇
  2007年   21588篇
  2006年   21981篇
  2005年   20541篇
  2004年   20096篇
  2003年   19035篇
  2002年   18548篇
  2001年   36393篇
  2000年   36958篇
  1999年   30430篇
  1998年   7904篇
  1997年   6685篇
  1996年   6984篇
  1995年   6636篇
  1994年   6104篇
  1993年   5597篇
  1992年   23016篇
  1991年   22961篇
  1990年   22350篇
  1989年   22117篇
  1988年   20057篇
  1987年   19444篇
  1986年   18483篇
  1985年   17322篇
  1984年   12715篇
  1983年   10757篇
  1982年   5929篇
  1979年   11529篇
  1978年   8140篇
  1977年   6837篇
  1976年   6599篇
  1975年   7271篇
  1974年   8502篇
  1973年   8146篇
  1972年   7664篇
  1971年   7136篇
  1970年   6880篇
  1969年   6309篇
  1968年   5782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