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   431852篇
  免费   13699篇
  国内免费   541篇
耳鼻咽喉   4474篇
儿科学   14560篇
妇产科学   8494篇
基础医学   53149篇
口腔科学   7532篇
临床医学   32531篇
内科学   88546篇
皮肤病学   7708篇
神经病学   39317篇
特种医学   16385篇
外国民族医学   101篇
外科学   60968篇
综合类   3531篇
现状与发展   1篇
一般理论   70篇
预防医学   41325篇
眼科学   7719篇
药学   27219篇
中国医学   1417篇
肿瘤学   31045篇
  2023年   1444篇
  2022年   1473篇
  2021年   4617篇
  2020年   2600篇
  2019年   4905篇
  2018年   29192篇
  2017年   21813篇
  2016年   23979篇
  2015年   6978篇
  2014年   7631篇
  2013年   11490篇
  2012年   24731篇
  2011年   38077篇
  2010年   27218篇
  2009年   18234篇
  2008年   34109篇
  2007年   37241篇
  2006年   15849篇
  2005年   17305篇
  2004年   17468篇
  2003年   17219篇
  2002年   14693篇
  2001年   6885篇
  2000年   7160篇
  1999年   6241篇
  1998年   1390篇
  1997年   1196篇
  1996年   987篇
  1995年   954篇
  1994年   852篇
  1992年   3441篇
  1991年   3106篇
  1990年   3017篇
  1989年   2697篇
  1988年   2523篇
  1987年   2361篇
  1986年   2211篇
  1985年   2008篇
  1984年   1496篇
  1983年   1256篇
  1979年   1273篇
  1978年   916篇
  1977年   849篇
  1975年   843篇
  1974年   1049篇
  1973年   1029篇
  1972年   980篇
  1971年   954篇
  1970年   903篇
  1969年   967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.
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.
9.
10.

Objective

The aim of this paper is to study the opportunity costs (OC) that are involved in being a caregiver and to compare them with the direct costs assumed by the State and the families. We evaluate direct cost (those that imply a payment-out-of-pocket) and indirect cost (those that imply a dedication in time). We hypothesized that costs increase with the severity of the dementia, with the educational level and active occupational situation of caregiver. They are greater if the caregiver is male, but if the patient and caregiver cohabit they are reduced.

Method

778 surveys were analyzed. Data was collected using a questionnaire specifically designed for the purpose, with the collaboration of Alzheimer's Diseases Associations in Andalusia (Spain). For the indirect cost, we used the reveal preferences method. For the comparison between groups an ANOVA and a MANOVA was done.

Results

The hypotheses were confirmed. The OC exponentially increases with severity. More than 55% of costs are assumed by families. Occupied people have higher educational level and incomes and contract more external support. Costs are significantly higher for male caregivers. Cohabiting reduces all kinds of costs.

Conclusions

The relationship between educational level and employment situation lead to think that if these variables are greater more people will seek professional support. Cultural reasons still maintain women as main caregivers for all educational levels. The existence of these informal caregivers as the main care providers is a saving for the State, and a brake for the development of professional supply.  相似文献   
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