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   1477468篇
  免费   104326篇
  国内免费   2416篇
耳鼻咽喉   20864篇
儿科学   48581篇
妇产科学   41894篇
基础医学   215881篇
口腔科学   40509篇
临床医学   124600篇
内科学   295349篇
皮肤病学   31944篇
神经病学   117596篇
特种医学   56153篇
外国民族医学   460篇
外科学   222504篇
综合类   27593篇
现状与发展   1篇
一般理论   363篇
预防医学   111181篇
眼科学   33159篇
药学   111863篇
  5篇
中国医学   3183篇
肿瘤学   80527篇
  2019年   11654篇
  2018年   18525篇
  2017年   13383篇
  2016年   14502篇
  2015年   16582篇
  2014年   21304篇
  2013年   32690篇
  2012年   47927篇
  2011年   50246篇
  2010年   28408篇
  2009年   25435篇
  2008年   47161篇
  2007年   51032篇
  2006年   50450篇
  2005年   49643篇
  2004年   47397篇
  2003年   45460篇
  2002年   44353篇
  2001年   62758篇
  2000年   64276篇
  1999年   54846篇
  1998年   15042篇
  1997年   13488篇
  1996年   13660篇
  1995年   12899篇
  1994年   12242篇
  1992年   43407篇
  1991年   42538篇
  1990年   41981篇
  1989年   40585篇
  1988年   37879篇
  1987年   36940篇
  1986年   35215篇
  1985年   33512篇
  1984年   24956篇
  1983年   21703篇
  1982年   12926篇
  1981年   11361篇
  1979年   23574篇
  1978年   16530篇
  1977年   14320篇
  1976年   13486篇
  1975年   14832篇
  1974年   17446篇
  1973年   16883篇
  1972年   16029篇
  1971年   14949篇
  1970年   13905篇
  1969年   13443篇
  1968年   12576篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.  相似文献   
82.
83.
84.
85.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
86.

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   
87.
88.
89.
90.
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