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   319篇
  免费   26篇
  国内免费   11篇
耳鼻咽喉   2篇
儿科学   10篇
妇产科学   2篇
基础医学   29篇
口腔科学   4篇
临床医学   44篇
内科学   61篇
皮肤病学   7篇
神经病学   8篇
特种医学   68篇
外科学   86篇
综合类   3篇
预防医学   5篇
眼科学   2篇
药学   19篇
肿瘤学   6篇
  2024年   1篇
  2023年   5篇
  2021年   5篇
  2020年   8篇
  2019年   3篇
  2018年   6篇
  2017年   9篇
  2016年   6篇
  2015年   5篇
  2014年   10篇
  2013年   11篇
  2012年   9篇
  2011年   21篇
  2010年   15篇
  2009年   18篇
  2008年   7篇
  2007年   14篇
  2006年   10篇
  2005年   5篇
  2004年   4篇
  2003年   3篇
  2001年   4篇
  2000年   3篇
  1999年   3篇
  1998年   17篇
  1997年   14篇
  1996年   9篇
  1995年   10篇
  1994年   10篇
  1993年   4篇
  1992年   7篇
  1991年   3篇
  1990年   4篇
  1989年   11篇
  1988年   7篇
  1987年   11篇
  1986年   12篇
  1985年   5篇
  1984年   7篇
  1983年   3篇
  1982年   5篇
  1981年   7篇
  1980年   5篇
  1979年   4篇
  1978年   5篇
  1977年   3篇
  1976年   5篇
  1975年   1篇
  1970年   1篇
  1964年   1篇
排序方式: 共有356条查询结果,搜索用时 31 毫秒
1.
2.
3.
Two patients presenting with signs and symptoms suggestive of nerve root compression secondary to extradural masses were found to have ligamentum flavum hematomas. Both patients had neurological deficits preoperatively and regained normal function postoperatively. There was no significant antecedent injury in either case. The symptom course was longer than that for spontaneous epidural hematoma. In one case, there was remodeling of bone, initially suggesting either infection or tumor.  相似文献   
4.
5.
6.
We describe a technique for conducting a CT-guided biopsy of the brachial plexus region, report two illustrative cases, discuss potential complications, and conclude that, in selected cases, biopsy of lesions in the region of the brachial plexus can be performed safely with CT guidance.  相似文献   
7.
Administration of supraphysiological doses of testosterone to normal men causes inhibition of spermatogenesis, but while most become azoospermic, 30-55% maintain a low rate of spermatogenesis. We have investigated whether there are differences in endogenous androgen production, of testicular and adrenal origin, which may be related to the degree of suppression of spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m. injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic, while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a specific testicular product, was reduced to <10% of pretreatment values, with no differences between the groups. Similar results were obtained for other markers of testicular steroidogenesis. Urinary and plasma adrenal androgens were also reduced during TE treatment: a statistically significant decrease in both (P < 0.001 and P < 0.05 respectively) was seen in the azoospermic but not oligozoospermic responders. These results suggest that testicular steroidogenesis is decreased to <10% by the administration of supraphysiological doses of exogenous testosterone. Differences in the degree of ongoing steroidogenesis in the testis do not appear to account for incomplete suppression of spermatogenesis, thus differences in androgen metabolism may underlie this heterogeneous response. A small but significant reduction in secretion of adrenal androgens was also detectable, the relevance of which is unclear.   相似文献   
8.
This article presents data gathered from young people in a poor urban community in New York City, the South Bronx. It seeks to help public health professionals better understand young people's perceptions of violence in the context of their daily lives. Sources of data include a street survey, five focus groups, interviews with incarcerated young males, and observations of several youth programs. These data suggest that violence is pervasive in the lives of both young men and women, although gender plays an important role in shaping the experience of violence. Other factors that influence the experience of violence include patterns of substance use, availability and use of weapons, and a perception that the police do not respect young people. Despite numerous challenges, many young people do take actions to reduce violence. The article suggests actions public health professionals can take to strengthen the ability of families, schools, youth organizations, and young people themselves to reduce violence in low-income urban communities.  相似文献   
9.
Monette  FC; Holden  SA 《Blood》1982,60(2):527-530
Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of "burst-promoting activity." In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells.  相似文献   
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