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   314611篇
  免费   38503篇
  国内免费   2739篇
耳鼻咽喉   7408篇
儿科学   10139篇
妇产科学   6403篇
基础医学   27094篇
口腔科学   6906篇
临床医学   35681篇
内科学   83903篇
皮肤病学   11723篇
神经病学   27764篇
特种医学   10301篇
外国民族医学   1篇
外科学   59853篇
综合类   1007篇
现状与发展   72篇
一般理论   25篇
预防医学   27010篇
眼科学   7662篇
药学   14024篇
中国医学   690篇
肿瘤学   18187篇
  2023年   5493篇
  2022年   1665篇
  2021年   5413篇
  2020年   7224篇
  2019年   4890篇
  2018年   12139篇
  2017年   10214篇
  2016年   11274篇
  2015年   11630篇
  2014年   18969篇
  2013年   21108篇
  2012年   15632篇
  2011年   16343篇
  2010年   15473篇
  2009年   17892篇
  2008年   14657篇
  2007年   13600篇
  2006年   15677篇
  2005年   12604篇
  2004年   11327篇
  2003年   9774篇
  2002年   9482篇
  2001年   8917篇
  2000年   8836篇
  1999年   7577篇
  1998年   4337篇
  1997年   3895篇
  1996年   3794篇
  1995年   3583篇
  1994年   2265篇
  1993年   1824篇
  1992年   3585篇
  1991年   3390篇
  1990年   3023篇
  1989年   2851篇
  1988年   2615篇
  1987年   2354篇
  1986年   2431篇
  1985年   2164篇
  1984年   1588篇
  1983年   1407篇
  1979年   1514篇
  1977年   1176篇
  1975年   1157篇
  1974年   1348篇
  1973年   1396篇
  1972年   1415篇
  1971年   1280篇
  1970年   1261篇
  1969年   1158篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.

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   
62.
63.
64.
65.
66.
67.
68.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  相似文献   
69.
70.
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them.  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