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   1277568篇
  免费   92795篇
  国内免费   1990篇
耳鼻咽喉   18195篇
儿科学   42319篇
妇产科学   37830篇
基础医学   187092篇
口腔科学   35426篇
临床医学   108181篇
内科学   251791篇
皮肤病学   26506篇
神经病学   99261篇
特种医学   50019篇
外国民族医学   366篇
外科学   197659篇
综合类   26547篇
现状与发展   1篇
一般理论   300篇
预防医学   92643篇
眼科学   29092篇
药学   97813篇
  1篇
中国医学   2496篇
肿瘤学   68815篇
  2018年   11827篇
  2015年   11627篇
  2014年   16016篇
  2013年   24370篇
  2012年   33586篇
  2011年   35996篇
  2010年   21224篇
  2009年   20045篇
  2008年   35017篇
  2007年   38012篇
  2006年   38550篇
  2005年   37845篇
  2004年   36436篇
  2003年   35416篇
  2002年   34963篇
  2001年   58142篇
  2000年   59619篇
  1999年   50705篇
  1998年   14248篇
  1997年   12820篇
  1996年   13079篇
  1995年   12353篇
  1994年   11762篇
  1993年   10862篇
  1992年   41010篇
  1991年   40373篇
  1990年   39903篇
  1989年   38731篇
  1988年   36131篇
  1987年   35368篇
  1986年   33747篇
  1985年   32147篇
  1984年   23936篇
  1983年   20824篇
  1982年   12390篇
  1981年   10934篇
  1980年   10210篇
  1979年   22646篇
  1978年   15884篇
  1977年   13730篇
  1976年   12976篇
  1975年   14205篇
  1974年   16688篇
  1973年   16082篇
  1972年   15323篇
  1971年   14230篇
  1970年   13217篇
  1969年   12732篇
  1968年   11980篇
  1967年   10481篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
61.
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   
62.
63.
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   
64.
65.
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   
66.
67.
68.
69.
70.
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease.  相似文献   
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