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   905724篇
  免费   57605篇
  国内免费   2311篇
耳鼻咽喉   12522篇
儿科学   28687篇
妇产科学   26144篇
基础医学   126743篇
口腔科学   24710篇
临床医学   74868篇
内科学   183488篇
皮肤病学   19008篇
神经病学   71527篇
特种医学   36484篇
外国民族医学   336篇
外科学   142230篇
综合类   19032篇
一般理论   247篇
预防医学   64599篇
眼科学   20114篇
药学   63858篇
  13篇
中国医学   1799篇
肿瘤学   49231篇
  2018年   9072篇
  2017年   7209篇
  2016年   7735篇
  2015年   8735篇
  2014年   12375篇
  2013年   19211篇
  2012年   25652篇
  2011年   27260篇
  2010年   16578篇
  2009年   15780篇
  2008年   26129篇
  2007年   27738篇
  2006年   27920篇
  2005年   27451篇
  2004年   26295篇
  2003年   25465篇
  2002年   25057篇
  2001年   41362篇
  2000年   42555篇
  1999年   36271篇
  1998年   9970篇
  1997年   9150篇
  1996年   9084篇
  1995年   8446篇
  1994年   8087篇
  1993年   7585篇
  1992年   28199篇
  1991年   26981篇
  1990年   26409篇
  1989年   25345篇
  1988年   23553篇
  1987年   23170篇
  1986年   22250篇
  1985年   21151篇
  1984年   15807篇
  1983年   13479篇
  1982年   8091篇
  1979年   14589篇
  1978年   10208篇
  1977年   8627篇
  1976年   8148篇
  1975年   8959篇
  1974年   10697篇
  1973年   10182篇
  1972年   9661篇
  1971年   8918篇
  1970年   8585篇
  1969年   8027篇
  1968年   7685篇
  1967年   7086篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
According to the current nutritional recommendations issued by professional diabetes and nutrition associations, diabetic patients should keep to a diet consisting of 45–60% carbohydrates, 10–20% protein, and not more than 35% fat. However, not all of these nutritional recommendations are evidence based. For example, current studies show that the intake of insoluble roughage may be underrepresented. It is also possible that diabetic patients could benefit from keeping to the lower end of the recommended range for carbohydrates (45%) and the upper end of the range advised for protein (20%).  相似文献   
7.
8.
Chronic obstructive pulmonary disease (COPD) is characterised by a local pulmonary inflammatory response to respiratory pollutants and by systemic inflammation. Tumour necrosis factor (TNF)-alpha has been implicated in systemic effects of COPD and operates by binding the p55 (R1) and p75 (R2) TNF-alpha receptors. To investigate the contribution of each TNF-alpha receptor in the pathogenesis of COPD, the present study examined the effects of chronic air or cigarette smoke (CS) exposure in TNF-alpha R1 knockout (KO) mice, TNF-alpha R2 KO mice and wild type (WT) mice. CS was found to significantly increase the protein levels of soluble TNF-alpha R1 (by four-fold) and TNF-alpha R2 (by 10-fold) in the bronchoalveolar lavage of WT mice. After 3 months, CS induced a prominent pulmonary inflammatory cell influx in WT and TNF-alpha R1 KO mice. In TNF-alpha R2 KO mice, CS-induced pulmonary inflammation was clearly attenuated. After 6 months, no emphysema was observed in CS-exposed TNF-alpha R2 KO mice in contrast to WT and TNF-alpha R1 KO mice. CS-exposed WT and TNF-alpha R1 KO mice failed to gain weight, whereas the body mass of TNF-alpha R2 KO mice was not affected. These current findings suggest that both tumour necrosis factor-alpha receptors contribute to the pathogenesis of chronic obstructive pulmonary disease, but tumour necrosis factor-alpha receptor-2 is the most active receptor in the development of inflammation, emphysema and systemic weight loss in this murine model of chronic obstructive pulmonary disease.  相似文献   
9.
10.
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   
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