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   1348431篇
  免费   98015篇
  国内免费   2216篇
耳鼻咽喉   19036篇
儿科学   44254篇
妇产科学   38803篇
基础医学   196705篇
口腔科学   36168篇
临床医学   115922篇
内科学   266542篇
皮肤病学   27289篇
神经病学   106246篇
特种医学   52761篇
外国民族医学   366篇
外科学   208920篇
综合类   27343篇
现状与发展   1篇
一般理论   386篇
预防医学   98286篇
眼科学   30704篇
药学   102698篇
  1篇
中国医学   2574篇
肿瘤学   73657篇
  2018年   14071篇
  2017年   10530篇
  2016年   11752篇
  2015年   13573篇
  2014年   18869篇
  2013年   28017篇
  2012年   39337篇
  2011年   41916篇
  2010年   24484篇
  2009年   22950篇
  2008年   39798篇
  2007年   42874篇
  2006年   43114篇
  2005年   42351篇
  2004年   40528篇
  2003年   39180篇
  2002年   38323篇
  2001年   58714篇
  2000年   60030篇
  1999年   51261篇
  1998年   14963篇
  1997年   13342篇
  1996年   13507篇
  1995年   12734篇
  1994年   12132篇
  1993年   11234篇
  1992年   41256篇
  1991年   40567篇
  1990年   40085篇
  1989年   38891篇
  1988年   36292篇
  1987年   35502篇
  1986年   33874篇
  1985年   32316篇
  1984年   24125篇
  1983年   20969篇
  1982年   12587篇
  1981年   11158篇
  1979年   22755篇
  1978年   16014篇
  1977年   13843篇
  1976年   13054篇
  1975年   14266篇
  1974年   16742篇
  1973年   16132篇
  1972年   15369篇
  1971年   14285篇
  1970年   13251篇
  1969年   12756篇
  1968年   12002篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
64.
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   
65.
66.
67.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  相似文献   
68.
69.
70.
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