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   864641篇
  免费   79710篇
  国内免费   3651篇
耳鼻咽喉   14366篇
儿科学   29049篇
妇产科学   20089篇
基础医学   115163篇
口腔科学   22002篇
临床医学   90811篇
内科学   182224篇
皮肤病学   23623篇
神经病学   65024篇
特种医学   32526篇
外国民族医学   77篇
外科学   145534篇
综合类   15273篇
现状与发展   74篇
一般理论   182篇
预防医学   59395篇
眼科学   19834篇
药学   55912篇
  3篇
中国医学   2376篇
肿瘤学   54465篇
  2021年   8547篇
  2020年   9198篇
  2019年   7639篇
  2018年   15075篇
  2017年   13243篇
  2016年   14953篇
  2015年   15766篇
  2014年   25399篇
  2013年   30853篇
  2012年   26398篇
  2011年   27453篇
  2010年   23106篇
  2009年   25990篇
  2008年   26136篇
  2007年   26010篇
  2006年   28805篇
  2005年   24755篇
  2004年   23574篇
  2003年   21531篇
  2002年   21129篇
  2001年   40292篇
  2000年   40113篇
  1999年   33795篇
  1998年   11593篇
  1997年   10176篇
  1996年   10387篇
  1995年   9889篇
  1994年   8082篇
  1993年   7222篇
  1992年   24521篇
  1991年   24495篇
  1990年   23512篇
  1989年   23418篇
  1988年   21172篇
  1987年   20417篇
  1986年   19519篇
  1985年   18194篇
  1984年   13385篇
  1983年   11415篇
  1982年   6571篇
  1979年   11958篇
  1978年   8588篇
  1977年   7329篇
  1976年   6922篇
  1975年   7629篇
  1974年   8831篇
  1973年   8481篇
  1972年   8058篇
  1971年   7422篇
  1970年   7194篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome.  相似文献   
32.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  相似文献   
33.
34.
35.
36.
37.
38.
39.
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   
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