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   2341051篇
  免费   175593篇
  国内免费   5846篇
耳鼻咽喉   32247篇
儿科学   79097篇
妇产科学   64200篇
基础医学   338878篇
口腔科学   63595篇
临床医学   217937篇
内科学   455848篇
皮肤病学   48893篇
神经病学   189959篇
特种医学   88693篇
外国民族医学   912篇
外科学   340348篇
综合类   51644篇
现状与发展   2篇
一般理论   800篇
预防医学   190942篇
眼科学   52038篇
药学   173611篇
  7篇
中国医学   5067篇
肿瘤学   127772篇
  2019年   18546篇
  2018年   26105篇
  2017年   19657篇
  2016年   21501篇
  2015年   24544篇
  2014年   33966篇
  2013年   52458篇
  2012年   71960篇
  2011年   76362篇
  2010年   44982篇
  2009年   42107篇
  2008年   71163篇
  2007年   75752篇
  2006年   76044篇
  2005年   73745篇
  2004年   71088篇
  2003年   68354篇
  2002年   66510篇
  2001年   107932篇
  2000年   111692篇
  1999年   94339篇
  1998年   26635篇
  1997年   24058篇
  1996年   24151篇
  1995年   22978篇
  1994年   21693篇
  1993年   20243篇
  1992年   75575篇
  1991年   74056篇
  1990年   71815篇
  1989年   68424篇
  1988年   63289篇
  1987年   62129篇
  1986年   58571篇
  1985年   56022篇
  1984年   42276篇
  1983年   35779篇
  1982年   21162篇
  1981年   19106篇
  1979年   38106篇
  1978年   26899篇
  1977年   22409篇
  1976年   21492篇
  1975年   22637篇
  1974年   27037篇
  1973年   26304篇
  1972年   24234篇
  1971年   22314篇
  1970年   20933篇
  1969年   18983篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
93.
French asthma patients may be supervised by general practitioners (GPs) and/or specialists. Therefore, this study examined asthma management in patients exclusively supervised by specialists (SPE), GPs, (GP) and both (GP+SPE group), and compared the findings. Asthma patients were consecutively recruited in 348 pharmacies. Each patient completed a questionnaire providing data on personal characteristics, asthma management, perception of disease and asthma supervision. Asthma control was measured using the Asthma Control Test. Questionnaires were linked to computerised records of medications which had been dispensed before inclusion in the study. From the 1,256 patients (mean age = 36.1 yrs, 54.3% females), 11.4, 36.6, and 52.0% were placed in the SPE, GP, and GP+SPE groups, respectively. During the previous 4 weeks, most patients in the SPE group were properly controlled (52.2 versus 26.4 and 21.5% in GP and GP+SPE groups, respectively). The SPE group made more use of fixed combinations of long-acting beta agonist and inhaled corticosteroid, while receiving less short-acting beta agonists, antitussives and antibiotics. Striking differences in symptoms and asthma management were observed according to the type of asthma supervision. The current results strongly support the need to improve the management of asthma in primary care, and the coordination of care between general practitioners and specialists.  相似文献   
94.
95.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.  相似文献   
96.
Research coordinators in intensive care are a growing specialty about which little is known. This cross-sectional study surveyed the Australia and New Zealand Intensive Care Research Coordinators' Group (n = 49) regarding demographics, education, employment history, job structure, and role content. Most research coordinators were highly qualified and experienced nurses who undertake pharmaceutical trials, multicenter projects, departmental medical and nursing research, audits and data registries, and their own projects.  相似文献   
97.
98.
99.
100.
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