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   194046篇
  免费   33955篇
  国内免费   2624篇
耳鼻咽喉   5677篇
儿科学   6767篇
妇产科学   3526篇
基础医学   7631篇
口腔科学   3460篇
临床医学   30360篇
内科学   56482篇
皮肤病学   8325篇
神经病学   17261篇
特种医学   7855篇
外国民族医学   4篇
外科学   48623篇
综合类   1269篇
现状与发展   75篇
一般理论   31篇
预防医学   9912篇
眼科学   4832篇
药学   4251篇
  1篇
中国医学   310篇
肿瘤学   13973篇
  2024年   719篇
  2023年   5191篇
  2022年   2451篇
  2021年   5039篇
  2020年   7185篇
  2019年   3837篇
  2018年   9327篇
  2017年   8724篇
  2016年   9963篇
  2015年   9987篇
  2014年   17465篇
  2013年   18094篇
  2012年   8991篇
  2011年   8991篇
  2010年   12313篇
  2009年   15808篇
  2008年   8264篇
  2007年   6567篇
  2006年   8701篇
  2005年   5786篇
  2004年   4873篇
  2003年   3517篇
  2002年   3400篇
  2001年   4288篇
  2000年   3425篇
  1999年   3580篇
  1998年   3876篇
  1997年   3616篇
  1996年   3534篇
  1995年   3339篇
  1994年   2051篇
  1993年   1659篇
  1992年   1542篇
  1991年   1577篇
  1990年   1198篇
  1989年   1322篇
  1988年   1153篇
  1987年   992篇
  1986年   1008篇
  1985年   861篇
  1984年   651篇
  1983年   586篇
  1982年   573篇
  1981年   469篇
  1980年   405篇
  1979年   369篇
  1978年   374篇
  1977年   441篇
  1975年   322篇
  1972年   327篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
33.
Background Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Somatic growth and adequate anticoagulation are of concern when children undergo valve replacement. We conducted this study to evaluate the performance of valves in this age group. Methods 42 children under the age of 13 years who underwent valve replacement were included in this study. Totally, 50 valves were implanted in 42 patients: 48 were mechanical prostheses, two were bioprosthetic both in pulmonary position. 37 (74%) valves were implanted in mitral position, 10 (20%) in aortic position, 1 (2%) in tricuspid position and 2 (4%) in pulmonary position. Preoperatively, 14 (33,3%) patients were in New York Heart Association (NYHA) class IV, while 27 (64.2%) were in NYHA class III. Results There were 2 (4.7%) hospital deaths and 2 (4.7%) late deaths while 2 (4.7%) patients were lost to follow up. The mean follow up period was 9.4 yrs. 35 (83.3%) patients are in NYHA Class I and free of all medications except warfarin. 3 (7.1%) patients have undergone 5 successful pregnancies. The median INR was 2.23. Major thrombo-embolic episode occurred in 1 (2.3%) patient. Conclusions In view of the problems of sizing, anticoagulation and need for re-operation at an early age, there is a reluctance to replace valves in children. This study shows that despite these problems, valve replacement can be undertaken safely and successfully in children, when repair has failed or not technically feasible.  相似文献   
34.
CONTEXT: The physician assistant profession has been moving toward requiring master's degrees for new practitioners, but some argue this could change the face of the discipline. PURPOSE: To see if there is an association between physician assistants' academic degrees and practice in primary care, in rural areas, and with the medically underserved. METHODS: Surveys were sent to 880 graduates of the first 32 University of Washington physician assistant classes through 2000. Respondents noted their academic degree at program entry and the highest degree attained at any time up to the time of survey. Relationships between practice characteristics and academic degree levels were tested by unadjusted odds ratios and logistic regression after controlling for year of graduation and sex. RESULTS: Of the 478 respondents, 54% worked in primary care, about 30% practiced in nonmetropolitan communities, and 42% reported providing care for the medically underserved. Respondents with no degree (33% of total at entry, 24% at survey) were significantly more likely than degree holders to work in primary care and nonmetropolitan areas. Respondents with no degree at program entry were significantly more likely, and those with no degree at the time of the survey were marginally more likely, to self-report work with the medically underserved. CONCLUSION: Respondents with no academic degree are significantly more likely to demonstrate a commitment to primary, rural, and underserved health care. These findings may inform the national debate about the impact of required advanced degrees on the practice patterns of nonphysician providers.  相似文献   
35.
36.
37.
38.
This review discusses treatment options for men with premature ejaculation (PE), a common sexual dysfunction characterized by short ejaculatory latency, decreased sexual satisfaction, and distress. For a number of reasons, including embarrassment and the belief that PE is a normal part of aging, that it has no effective treatment, or that it will resolve itself, few men with PE seek treatment. Although several treatment options exist (eg, behavioral, cognitive, and sex therapy methods; desensitizing drugs; off-label use of antidepressants, phosphodiesterase type 5 inhibitors, or à-blockers), the majority of men with PE are not satisfied with their results. New pharmacologic drugs develped specifically for the treatment of PE are undergoing evaluation in clinical trials. For example, recent clinical research studies have revealed on-demand administration of one such drug, dapoxetine, which achieved significant improvements in ejaculatory latency, control over ejaculation, and satisfaction with sexual intercourse. In addition, partners of men who received dapoxetine likewise reported improved satisfaction with sexual intercourse. Future studies may reveal that integration of pharmacologic drugs with psychologic and/or behavioral therapy techniques may be the optimal approach to the management of PE. PE is a treatable condition, and new drugs in development may provide benefits over those available.  相似文献   
39.
40.
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