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   1335922篇
  免费   100269篇
  国内免费   4274篇
耳鼻咽喉   16802篇
儿科学   43592篇
妇产科学   36377篇
基础医学   197910篇
口腔科学   35909篇
临床医学   129648篇
内科学   258175篇
皮肤病学   26384篇
神经病学   111897篇
特种医学   48204篇
外国民族医学   366篇
外科学   184191篇
综合类   28799篇
现状与发展   1篇
一般理论   462篇
预防医学   114460篇
眼科学   28980篇
药学   98881篇
  6篇
中国医学   3170篇
肿瘤学   76251篇
  2021年   10919篇
  2019年   11648篇
  2018年   16331篇
  2017年   12294篇
  2016年   13250篇
  2015年   15194篇
  2014年   20816篇
  2013年   32082篇
  2012年   44268篇
  2011年   46909篇
  2010年   27084篇
  2009年   24937篇
  2008年   42743篇
  2007年   45085篇
  2006年   45202篇
  2005年   43615篇
  2004年   41598篇
  2003年   39516篇
  2002年   38335篇
  2001年   60870篇
  2000年   62539篇
  1999年   52290篇
  1998年   14594篇
  1997年   13282篇
  1996年   13128篇
  1995年   12462篇
  1994年   11633篇
  1993年   10923篇
  1992年   41582篇
  1991年   40772篇
  1990年   39455篇
  1989年   37352篇
  1988年   34594篇
  1987年   33709篇
  1986年   32162篇
  1985年   30657篇
  1984年   23048篇
  1983年   19599篇
  1982年   11758篇
  1979年   20817篇
  1978年   14820篇
  1977年   12076篇
  1976年   11881篇
  1975年   12119篇
  1974年   14805篇
  1973年   14475篇
  1972年   13364篇
  1971年   12434篇
  1970年   11494篇
  1969年   10421篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
A 19-item survey instrument was designed and mailed by the Infectious Diseases Society of America to its membership to determine the media preferred by infectious diseases physicians for continuing medical education on general topics and on antimicrobial resistance. The objective of the survey was to offer the developers of educational programs knowledge on which to base more-effective ways to deliver educational materials to physicians in this specialty.  相似文献   
72.
Knowing Ron     
Spechko  Phyllis L. 《JAMA》2006,296(7):738
  相似文献   
73.
74.
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   
75.
76.
77.
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   
78.
79.
80.
Fibroblasts incorporated within collagen gels induce a cell-mediated contraction of the gel to form a three-dimensional, tissue-like structure by a mechanism thought to mimic wound contraction in vivo . In this study a gel contraction model was used to investigate the ability of fibroblasts derived from adult gingiva, adult skin and fetal skin to organise a collagen matrix. In addition the effects of interleukin-1β (IL-1β) on the contraction process was also investigated. Over the concentration range 5-50 U/ml, IL-1β induced a statistically significant inhibition of gel contraction in all fibroblast cell types ( P <0.05), although fetal fibroblasts appeared least responsive and gingival fibroblasts most responsive to the inhibitory effects of this cytokine. Comparison of gel contraction by the different fibroblast strains indicated that fetal and gingival fibroblasts shared similar contraction kinetics. For the adult skin fibroblasts, three of five strains studied showed significantly diminished levels of gel contraction compared to fetal and gingival cells. This apparent difference in fibroblast phenotype may, at least in part, explain the fetal-like wound healing pattern seen in the oral mucosa.  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