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   1374篇
  免费   104篇
  国内免费   15篇
耳鼻咽喉   17篇
儿科学   62篇
妇产科学   16篇
基础医学   156篇
口腔科学   37篇
临床医学   158篇
内科学   292篇
皮肤病学   17篇
神经病学   114篇
特种医学   143篇
外科学   156篇
综合类   59篇
一般理论   3篇
预防医学   95篇
眼科学   4篇
药学   94篇
肿瘤学   70篇
  2020年   13篇
  2019年   16篇
  2018年   17篇
  2017年   10篇
  2016年   11篇
  2015年   14篇
  2014年   18篇
  2013年   38篇
  2012年   32篇
  2011年   46篇
  2010年   22篇
  2009年   28篇
  2008年   37篇
  2007年   49篇
  2006年   47篇
  2005年   53篇
  2004年   46篇
  2003年   42篇
  2002年   15篇
  2001年   25篇
  2000年   22篇
  1999年   37篇
  1998年   35篇
  1997年   44篇
  1996年   55篇
  1995年   29篇
  1994年   30篇
  1993年   30篇
  1992年   28篇
  1991年   37篇
  1990年   40篇
  1989年   38篇
  1988年   34篇
  1987年   34篇
  1986年   43篇
  1985年   25篇
  1984年   26篇
  1983年   29篇
  1982年   15篇
  1981年   12篇
  1980年   15篇
  1979年   21篇
  1978年   28篇
  1977年   17篇
  1976年   27篇
  1975年   10篇
  1974年   16篇
  1973年   18篇
  1971年   12篇
  1969年   9篇
排序方式: 共有1493条查询结果,搜索用时 15 毫秒
1.
2.
The ability of the calcium entry blocker verapamil to ameliorate the effects of renal ischemia was studied in ten sheep. Postanesthesia, bilateral cutaneous ureterostomies were placed in each sheep to facilitate urine collection and analysis. Both kidneys were made ischemic for one hour by occluding each renal artery. However, immediately before occlusion of the right renal artery, 0.05 mg/kg of verapamil was injected into the artery. Comparison of urinary creatinine excretion and urine volume for 72 h after reversal of ischemia demonstrated that those kidneys pretreated with verapamil had greater functional preservation (p less than .05). In this study, verapamil appeared to provide protection against renal damage after an ischemic insult.  相似文献   
3.
4.
5.
Abstract: Many students in the United States, particularly those from lower income or racially/ethnically diverse families, are exposed to clusters of risk factors that have a negative impact on school success. This study examined the association between the number of supportive and caring adults in the home, school, and neighborhood and the school engagement of students in early adolescence. Results revealed that students who reported such supportive adults in their lives also reported higher levels of psychological and behavioral engagement with their schooling. Additionally, including measures of environmental risk factors in analytical models of the school engagement of middle school students reduced otherwise statistically significant race/ethnicity differences to nonsignificance. Implications for practice and policy are discussed.  相似文献   
6.
7.
8.
9.
10.
Intravesical immunotherapy with bacillus Calmette-Guerin (BCG), Corynebacterium parvum (CP), keyhole limpet hemocyanin (KLH), and an extract of Allium sativum (AS) was studied in mice transplanted intravesically with mouse bladder tumor cells (MBT-2). Female C3H/He mice were anesthetized with sodium pentobarbital. Two X 10(5) MBT-2 cells were delivered into the bladder transurethrally using a small catheter, immediately after the posterior wall of the bladder had been electrocauterized. Bladder tumor became palpable or demonstrable microscopically in two weeks. Immunotherapy with BCG (2 X 10(6) CFU), CP (250 micrograms), KLH (50 micrograms), or AS (25 mg) was administered directly into the bladder via urethral catheter on day 1, day 6, or days 1 and 6. On day 21 the bladders and spleens were excised and weighed, and the bladders were examined macroscopically and microscopically for evidence of tumor. The results of the study showed that two treatments given one and six days after tumor transplant yielded the lowest tumor incidence and that CP and AS appeared equally effective or even slightly more effective than BCG in this model. These results suggest that clinical evaluation of CP or AS may be worthwhile.  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