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   249839篇
  免费   13644篇
  国内免费   2374篇
医药卫生   265857篇
  2023年   1816篇
  2022年   2047篇
  2021年   6390篇
  2020年   3946篇
  2019年   6002篇
  2018年   8414篇
  2017年   5562篇
  2016年   5690篇
  2015年   6668篇
  2014年   7944篇
  2013年   10645篇
  2012年   17115篇
  2011年   17835篇
  2010年   9468篇
  2009年   7279篇
  2008年   13672篇
  2007年   14251篇
  2006年   13805篇
  2005年   13134篇
  2004年   11696篇
  2003年   10909篇
  2002年   10105篇
  2001年   6206篇
  2000年   6677篇
  1999年   5279篇
  1998年   1598篇
  1997年   1206篇
  1996年   1039篇
  1995年   931篇
  1992年   2670篇
  1991年   2385篇
  1990年   2309篇
  1989年   1946篇
  1988年   1882篇
  1987年   1728篇
  1986年   1746篇
  1985年   1634篇
  1984年   1199篇
  1983年   1012篇
  1979年   1264篇
  1975年   917篇
  1974年   1165篇
  1973年   1218篇
  1972年   1152篇
  1971年   1113篇
  1970年   1039篇
  1969年   1123篇
  1968年   1121篇
  1967年   993篇
  1966年   901篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
41.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
42.
43.
44.
45.
Epidermolysis bullosa simplex (EBS) is a skin fragility disorder resulting from mutations of structural proteins in the epidermis. We provide a brief report of long‐term survival and reproduction in a mother with EBS due to keratin 5 (KRT5) c.1429G > A (p.E477K) mutation, which causes a particularly severe form of the disease.  相似文献   
46.
47.
48.
49.

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   
50.
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