首页 | 官方网站   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   368488篇
  免费   16887篇
  国内免费   1215篇
医药卫生   386590篇
  2023年   1962篇
  2022年   1801篇
  2021年   5819篇
  2020年   3522篇
  2019年   6370篇
  2018年   11211篇
  2017年   7341篇
  2016年   7447篇
  2015年   8437篇
  2014年   9288篇
  2013年   14240篇
  2012年   23840篇
  2011年   24272篇
  2010年   12334篇
  2009年   9409篇
  2008年   20423篇
  2007年   21725篇
  2006年   20342篇
  2005年   19808篇
  2004年   18541篇
  2003年   17103篇
  2002年   16268篇
  2001年   10177篇
  2000年   10636篇
  1999年   8926篇
  1998年   1706篇
  1997年   1318篇
  1992年   5106篇
  1991年   4566篇
  1990年   4455篇
  1989年   3989篇
  1988年   3755篇
  1987年   3476篇
  1986年   3423篇
  1985年   3169篇
  1984年   2323篇
  1983年   1989篇
  1979年   2279篇
  1978年   1557篇
  1977年   1500篇
  1975年   1597篇
  1974年   1998篇
  1973年   2060篇
  1972年   1918篇
  1971年   1871篇
  1970年   1757篇
  1969年   1879篇
  1968年   1795篇
  1967年   1559篇
  1966年   1409篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.

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   
3.
4.
5.
6.
7.
8.
9.
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.

Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.

Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.

Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality.  相似文献   
10.
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-23

京公网安备 11010802026262号