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   735067篇
  免费   43830篇
  国内免费   998篇
耳鼻咽喉   9798篇
儿科学   23477篇
妇产科学   18054篇
基础医学   116764篇
口腔科学   19648篇
临床医学   62017篇
内科学   142305篇
皮肤病学   17962篇
神经病学   56212篇
特种医学   25077篇
外国民族医学   164篇
外科学   104397篇
综合类   9402篇
一般理论   180篇
预防医学   58918篇
眼科学   16461篇
药学   56039篇
中国医学   1671篇
肿瘤学   41349篇
  2021年   6377篇
  2019年   7142篇
  2018年   12011篇
  2017年   8302篇
  2016年   8720篇
  2015年   9742篇
  2014年   11515篇
  2013年   18323篇
  2012年   28275篇
  2011年   29621篇
  2010年   15881篇
  2009年   13426篇
  2008年   26802篇
  2007年   28791篇
  2006年   27842篇
  2005年   27153篇
  2004年   26004篇
  2003年   24354篇
  2002年   23639篇
  2001年   29433篇
  2000年   30518篇
  1999年   25414篇
  1998年   6255篇
  1997年   5389篇
  1996年   5701篇
  1995年   5219篇
  1992年   18598篇
  1991年   18913篇
  1990年   18904篇
  1989年   18062篇
  1988年   16757篇
  1987年   16420篇
  1986年   15492篇
  1985年   14695篇
  1984年   10923篇
  1983年   9325篇
  1982年   5194篇
  1979年   10506篇
  1978年   7641篇
  1977年   6511篇
  1976年   6197篇
  1975年   7136篇
  1974年   8552篇
  1973年   8063篇
  1972年   7820篇
  1971年   7543篇
  1970年   6979篇
  1969年   6729篇
  1968年   6276篇
  1967年   5634篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
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   
8.
Abstract

This study is a single-center, retrospective analysis of postmenopausal women presenting with dyspareunia and vulvar pain, aiming to evaluate relative effectiveness of vestibular CO2 laser therapy as a treatment. Three monthly sessions of laser were performed to each patient and thereafter a three-months follow-up was stablished. A total number of 72 patients undergoing vestibular laser treatment were recruited from patient files in the period between 2016 and 2018. Among these, 39 women also received a concomitant treatment with ospemifene (60?mg/day) during the study period. There was a statistically significant reduction of all the symptoms in both groups up to the three month follow-up. Regarding dryness and dyspareunia, the relief tent to be more prominent in the ospemifene?+?laser group at all follow-ups and remained statistically significant at three-month follow-up. Specifically, vestibular dryness was significantly lower in the ospemifene?+?laser group compared with the laser treatment group (?87% vs???34%, respectively), and the vestibular health score started declining faster in the ospemifene?+?laser group. Although, additional research is needed to understand the mechanism of action, our data shows that a combination regimen of laser and ospemifene may improve clinical effectiveness for long-term treatment of symptoms associated with the under-recognized genitourinary syndrome of menopause.  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