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   923246篇
  免费   63993篇
  国内免费   2412篇
耳鼻咽喉   12659篇
儿科学   29208篇
妇产科学   26548篇
基础医学   130099篇
口腔科学   25013篇
临床医学   77017篇
内科学   188883篇
皮肤病学   19577篇
神经病学   73434篇
特种医学   37094篇
外国民族医学   339篇
外科学   145461篇
综合类   19284篇
一般理论   275篇
预防医学   66367篇
眼科学   20530篇
药学   65301篇
  1篇
中国医学   1852篇
肿瘤学   50709篇
  2018年   9434篇
  2017年   7421篇
  2016年   7992篇
  2015年   9103篇
  2014年   12934篇
  2013年   20069篇
  2012年   26937篇
  2011年   28665篇
  2010年   17426篇
  2009年   16665篇
  2008年   27499篇
  2007年   29269篇
  2006年   29442篇
  2005年   29061篇
  2004年   27780篇
  2003年   26886篇
  2002年   26444篇
  2001年   41681篇
  2000年   42812篇
  1999年   36582篇
  1998年   10322篇
  1997年   9458篇
  1996年   9348篇
  1995年   8691篇
  1994年   8313篇
  1993年   7796篇
  1992年   28443篇
  1991年   27225篇
  1990年   26610篇
  1989年   25548篇
  1988年   23733篇
  1987年   23339篇
  1986年   22436篇
  1985年   21335篇
  1984年   15979篇
  1983年   13654篇
  1982年   8285篇
  1981年   7262篇
  1979年   14711篇
  1978年   10326篇
  1977年   8753篇
  1976年   8248篇
  1975年   9065篇
  1974年   10788篇
  1973年   10264篇
  1972年   9741篇
  1971年   8991篇
  1970年   8633篇
  1969年   8070篇
  1968年   7732篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
13.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
14.
Setting goals to maintain hope.   总被引:3,自引:0,他引:3  
  相似文献   
15.
16.
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.  相似文献   
17.
18.
19.
20.
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