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   1281365篇
  免费   92947篇
  国内免费   2032篇
耳鼻咽喉   18341篇
儿科学   42485篇
妇产科学   38020篇
基础医学   187315篇
口腔科学   35631篇
临床医学   108599篇
内科学   252593篇
皮肤病学   26567篇
神经病学   99441篇
特种医学   50177篇
外国民族医学   366篇
外科学   198580篇
综合类   26604篇
现状与发展   1篇
一般理论   300篇
预防医学   92687篇
眼科学   29245篇
药学   97944篇
  1篇
中国医学   2500篇
肿瘤学   68947篇
  2018年   11932篇
  2015年   11788篇
  2014年   16183篇
  2013年   24598篇
  2012年   33901篇
  2011年   36261篇
  2010年   21411篇
  2009年   20196篇
  2008年   35366篇
  2007年   38373篇
  2006年   38912篇
  2005年   38146篇
  2004年   36648篇
  2003年   35590篇
  2002年   35083篇
  2001年   58182篇
  2000年   59671篇
  1999年   50758篇
  1998年   14257篇
  1997年   12831篇
  1996年   13088篇
  1995年   12352篇
  1994年   11761篇
  1993年   10870篇
  1992年   40992篇
  1991年   40370篇
  1990年   39890篇
  1989年   38706篇
  1988年   36111篇
  1987年   35350篇
  1986年   33723篇
  1985年   32134篇
  1984年   23923篇
  1983年   20818篇
  1982年   12377篇
  1981年   10927篇
  1980年   10204篇
  1979年   22635篇
  1978年   15877篇
  1977年   13730篇
  1976年   12970篇
  1975年   14201篇
  1974年   16682篇
  1973年   16076篇
  1972年   15318篇
  1971年   14232篇
  1970年   13216篇
  1969年   12732篇
  1968年   11978篇
  1967年   10478篇
排序方式: 共有10000条查询结果,搜索用时 15 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