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   428234篇
  免费   13467篇
  国内免费   472篇
医药卫生   442173篇
  2023年   1448篇
  2022年   1075篇
  2021年   4119篇
  2020年   2451篇
  2019年   4604篇
  2018年   29408篇
  2017年   21944篇
  2016年   24091篇
  2015年   7275篇
  2014年   7564篇
  2013年   11496篇
  2012年   25029篇
  2011年   38328篇
  2010年   27236篇
  2009年   17973篇
  2008年   34154篇
  2007年   37264篇
  2006年   15933篇
  2005年   17324篇
  2004年   17406篇
  2003年   17036篇
  2002年   14466篇
  2001年   6556篇
  2000年   6756篇
  1999年   5827篇
  1998年   1187篇
  1997年   1010篇
  1996年   867篇
  1995年   812篇
  1992年   3292篇
  1991年   3020篇
  1990年   2896篇
  1989年   2605篇
  1988年   2448篇
  1987年   2262篇
  1986年   2137篇
  1985年   1947篇
  1984年   1446篇
  1983年   1231篇
  1979年   1233篇
  1978年   867篇
  1977年   814篇
  1975年   821篇
  1974年   1016篇
  1973年   1007篇
  1972年   941篇
  1971年   932篇
  1970年   885篇
  1969年   938篇
  1968年   813篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.

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   
4.
5.
6.
7.
8.
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   
9.
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