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   246718篇
  免费   11856篇
  国内免费   479篇
耳鼻咽喉   3247篇
儿科学   7627篇
妇产科学   5036篇
基础医学   35244篇
口腔科学   5853篇
临床医学   19573篇
内科学   54604篇
皮肤病学   6426篇
神经病学   22012篇
特种医学   7434篇
外国民族医学   101篇
外科学   31048篇
综合类   1075篇
一般理论   66篇
预防医学   22232篇
眼科学   4754篇
药学   17236篇
  1篇
中国医学   728篇
肿瘤学   14756篇
  2023年   1357篇
  2022年   1073篇
  2021年   3859篇
  2020年   2279篇
  2019年   4223篇
  2018年   7865篇
  2017年   5217篇
  2016年   5255篇
  2015年   5961篇
  2014年   6251篇
  2013年   9965篇
  2012年   17038篇
  2011年   16959篇
  2010年   8546篇
  2009年   6390篇
  2008年   14584篇
  2007年   15513篇
  2006年   14365篇
  2005年   14107篇
  2004年   13230篇
  2003年   12077篇
  2002年   11382篇
  2001年   6253篇
  2000年   6340篇
  1999年   5617篇
  1998年   962篇
  1997年   792篇
  1996年   759篇
  1992年   3227篇
  1991年   2897篇
  1990年   2757篇
  1989年   2528篇
  1988年   2380篇
  1987年   2206篇
  1986年   2101篇
  1985年   1909篇
  1984年   1430篇
  1983年   1218篇
  1982年   714篇
  1979年   1225篇
  1978年   864篇
  1977年   811篇
  1975年   808篇
  1974年   997篇
  1973年   1009篇
  1972年   943篇
  1971年   931篇
  1970年   870篇
  1969年   909篇
  1968年   789篇
排序方式: 共有10000条查询结果,搜索用时 15 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