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   164797篇
  免费   6787篇
  国内免费   422篇
耳鼻咽喉   2193篇
儿科学   4896篇
妇产科学   3804篇
基础医学   23679篇
口腔科学   5429篇
临床医学   9485篇
内科学   36478篇
皮肤病学   4523篇
神经病学   13191篇
特种医学   4379篇
外国民族医学   1篇
外科学   18917篇
综合类   809篇
一般理论   24篇
预防医学   19702篇
眼科学   4332篇
药学   12843篇
  2篇
中国医学   658篇
肿瘤学   6661篇
  2023年   819篇
  2021年   2432篇
  2020年   1373篇
  2019年   2811篇
  2018年   4969篇
  2017年   3093篇
  2016年   3075篇
  2015年   3437篇
  2014年   3753篇
  2013年   5768篇
  2012年   10037篇
  2011年   10624篇
  2010年   5290篇
  2009年   3846篇
  2008年   8705篇
  2007年   9398篇
  2006年   8983篇
  2005年   8599篇
  2004年   7945篇
  2003年   7454篇
  2002年   7092篇
  2001年   4902篇
  2000年   5474篇
  1999年   4165篇
  1998年   827篇
  1997年   597篇
  1992年   2243篇
  1991年   2021篇
  1990年   2008篇
  1989年   1733篇
  1988年   1648篇
  1987年   1544篇
  1986年   1590篇
  1985年   1494篇
  1984年   1061篇
  1983年   906篇
  1979年   1209篇
  1978年   813篇
  1977年   797篇
  1976年   766篇
  1975年   890篇
  1974年   1119篇
  1973年   1164篇
  1972年   1110篇
  1971年   1077篇
  1970年   1008篇
  1969年   1082篇
  1968年   1105篇
  1967年   977篇
  1966年   879篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

Materials and methods

Initially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21 days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization.

Results

EGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10 μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10 μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21 days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation.

Conclusion

This work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy.  相似文献   
25.
26.
27.
28.
29.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  相似文献   
30.
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