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   1334535篇
  免费   96008篇
  国内免费   2908篇
耳鼻咽喉   19713篇
儿科学   40221篇
妇产科学   38665篇
基础医学   187253篇
口腔科学   39820篇
临床医学   112585篇
内科学   262361篇
皮肤病学   30279篇
神经病学   106485篇
特种医学   53735篇
外国民族医学   435篇
外科学   208324篇
综合类   31037篇
现状与发展   6篇
一般理论   437篇
预防医学   91955篇
眼科学   31363篇
药学   100134篇
  3篇
中国医学   2987篇
肿瘤学   75653篇
  2018年   11751篇
  2015年   11885篇
  2014年   16697篇
  2013年   25270篇
  2012年   33056篇
  2011年   34915篇
  2010年   20753篇
  2009年   20242篇
  2008年   33622篇
  2007年   36730篇
  2006年   37290篇
  2005年   36050篇
  2004年   35135篇
  2003年   34100篇
  2002年   33640篇
  2001年   63653篇
  2000年   65354篇
  1999年   55407篇
  1998年   14679篇
  1997年   13467篇
  1996年   12955篇
  1995年   12234篇
  1994年   11474篇
  1992年   42781篇
  1991年   41305篇
  1990年   40576篇
  1989年   39570篇
  1988年   36981篇
  1987年   36418篇
  1986年   34914篇
  1985年   33112篇
  1984年   24828篇
  1983年   21056篇
  1982年   12671篇
  1981年   11572篇
  1980年   10776篇
  1979年   23928篇
  1978年   17075篇
  1977年   14843篇
  1976年   13391篇
  1975年   15277篇
  1974年   18088篇
  1973年   17570篇
  1972年   16812篇
  1971年   15722篇
  1970年   14915篇
  1969年   14348篇
  1968年   13461篇
  1967年   12016篇
  1966年   11260篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
161.
162.
163.
Monatsschrift Kinderheilkunde - Fusionen und Übernahmen in der Pharmaindustrie haben zu einer Konzentration geführt, von der auch die Impfstoffproduktion mit nur noch wenigen global...  相似文献   
164.
Abstract

The leading cause of death of adolescents in developed countries is injury. Alcohol is a major contributor to adolescent injury. Most of the injury deaths in youth are caused by traffic crashes. Driving under the influence (DUI) and riding with a driver who is under the influence (RUI) of alcohol increase the risk of road crash. The focus of this study is how adolescents’ risk of DUI and RUI differ in relation to their experience of parental control and peer pressure to substance use, other risky behaviours and leisure time activities. The analyses are based on data from the European School Survey Project on Alcohol and Other Drugs collected from 15- to 16-year-old Finnish adolescents in 2015 (n?=?4049, response rate 88.7%). The study shows that problems tend to entangle in some adolescent groups in which DUI and RUI are also more common. Adolescents with higher probability of using various substances, of starting alcohol use at young age, of experiencing weak parental control, and high peer pressure are at higher risk of DUI and RUI. The results indicate that professionals and authorities handling underage DUI and RUI ought to consider adolescents’ situation as a whole.  相似文献   
165.
166.
Postoperative pulmonary complications are associated with an increase in mortality, morbidity and healthcare utilisation. The Agency for Healthcare Research and Quality recommends risk assessment for postoperative respiratory complications in patients undergoing surgery. In this hospital registry study of adult patients undergoing non-cardiac surgery between 2005 and 2017 at two independent healthcare networks, a prediction instrument for early postoperative tracheal re-intubation was developed and externally validated. This was based on the development of the Score for Prediction Of Postoperative Respiratory Complications. For predictor selection, stepwise backward logistic regression and bootstrap resampling were applied. Development and validation cohorts were represented by 90,893 patients at Partners Healthcare and 67,046 patients at Beth Israel Deaconess Medical Center, of whom 699 (0.8%) and 587 (0.9%) patients, respectively, had their tracheas re-intubated. In addition to five pre-operative predictors identified in the Score for Prediction Of Postoperative Respiratory Complications, the final model included seven additional intra-operative predictors: early post-tracheal intubation desaturation; prolonged duration of surgery; high fraction of inspired oxygen; high vasopressor dose; blood transfusion; the absence of volatile anaesthetic use; and the absence of lung-protective ventilation. The area under the receiver operating characteristic curve for the new score was significantly greater than that of the original Score for Prediction Of Postoperative Respiratory Complications (0.84 [95%CI 0.82–0.85] vs. 0.76 [95%CI 0.75–0.78], respectively; p < 0.001). This may allow clinicians to develop and implement strategies to decrease the risk of early postoperative tracheal re-intubation.  相似文献   
167.
168.
Objective: A multidisciplinary vocational rehabilitation programme, the Vocational Enablement Protocol (VEP) was developed to address the specific needs of employees with hearing difficulties. In the current study we evaluated the process of implementing the VEP in audiologic care among employees with hearing impairment. Design: In conjunction with a randomized controlled trial, we collected and analysed data on seven process parameters: recruitment, reach, fidelity, dose delivered, dose received and implemented, satisfaction, and perceived benefit. Study sample: Sixty-six employees with hearing impairment participated in the VEP. The multidisciplinary team providing the VEP comprised six professionals. Results: The professionals performed the VEP according to the protocol. Of the recommendations delivered by the professionals, 31% were perceived as implemented by the employees. Compliance rate was highest for hearing-aid uptake (51%). Both employees and professionals were highly satisfied with the VEP. Participants rated good perceived benefit from it. Conclusions: Our results indicate that the VEP could be a useful treatment for employees with hearing difficulties from a process evaluation perspective. Implementation research in the audiological setting should be encouraged in order to further provide insight into parameters facilitating or hindering successful implementation of an intervention and to improve its quality and efficacy.  相似文献   
169.
Optical coherence tomography (OCT) is a noninvasive imaging tool used in vivo in real time for diagnosis, treatment delineation and monitoring of basal cell carcinoma (BCC). Features of BCC on OCT have been widely described and reviewed. However, the diagnostic accuracy of OCT in these various applications is unclear. We systematically reviewed the literature to assess the accuracy of OCT in diagnosis and management of BCC using the Embase and Medline databases. In total 179 unique references were identified in the initial search, of which 22 studies with 556 histologically proven BCCs were eligible. Assessment of the quality of eligible studies was undertaken using the STROBE criteria. Data extraction and quality assessment were performed independently by the two authors. This systematic review provides an overview of the clinical applications of OCT in the diagnosis and management of BCC. OCT has been suggested to be useful in the diagnosis, treatment planning and treatment monitoring of BCC. As the technology improves and its utility increases, further studies with good methodological quality will be needed to implement OCT into daily practice.  相似文献   
170.
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