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   104001篇
  免费   6448篇
  国内免费   783篇
耳鼻咽喉   1219篇
儿科学   3007篇
妇产科学   2414篇
基础医学   13977篇
口腔科学   2317篇
临床医学   8598篇
内科学   22964篇
皮肤病学   2335篇
神经病学   9668篇
特种医学   4268篇
外国民族医学   23篇
外科学   14664篇
综合类   1678篇
一般理论   49篇
预防医学   5820篇
眼科学   1643篇
药学   8250篇
  3篇
中国医学   528篇
肿瘤学   7807篇
  2023年   433篇
  2022年   1038篇
  2021年   1882篇
  2020年   1253篇
  2019年   1766篇
  2018年   2188篇
  2017年   1702篇
  2016年   1830篇
  2015年   2136篇
  2014年   2796篇
  2013年   4063篇
  2012年   5581篇
  2011年   5738篇
  2010年   3760篇
  2009年   3270篇
  2008年   5118篇
  2007年   5365篇
  2006年   5128篇
  2005年   4934篇
  2004年   5130篇
  2003年   4918篇
  2002年   5001篇
  2001年   3803篇
  2000年   3718篇
  1999年   3057篇
  1998年   1214篇
  1997年   963篇
  1996年   868篇
  1995年   843篇
  1994年   718篇
  1993年   715篇
  1992年   1793篇
  1991年   1782篇
  1990年   1498篇
  1989年   1458篇
  1988年   1327篇
  1987年   1195篇
  1986年   1180篇
  1985年   1042篇
  1984年   772篇
  1983年   702篇
  1982年   459篇
  1981年   394篇
  1979年   571篇
  1978年   416篇
  1975年   435篇
  1974年   484篇
  1973年   468篇
  1972年   423篇
  1971年   394篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
Following the outbreak of poliomyelitis in Gazankulu in 1982, the immunisation services in Gazankulu were thoroughly examined. As a result of this, a comprehensive immunisation policy for Gazankulu was accepted in November 1986. The broad aim of the policy is to provide effective immunisation to all Gazankulu residents against tuberculosis, diphtheria, pertussis, tetanus, poliomyelitis and measles. A specific objective is that by the end of 1987, 85% of under-5s should have been vaccinated against these six diseases and by the end of 1990 this percentage should be 97%. The detailed strategies to reach these objectives are highlighted. Within the framework of the objectives, the policy allows different areas to formulate individual strategies. Programme monitoring and community involvement are two crucial aspects of the policy and these are discussed in detail. The early successes and difficulities in implementing this policy are discussed.  相似文献   
64.
Information regarding breast feeding practices of 600 children below 3 years of age attending hospital OPDs and private clinics during 1984-85 were collected. 51.3% received breast milk within 24 hrs. of birth, mean duration of breast feeding being 6 months. 68% of Infants had been given prelacteal feeds. 34% children were exclusively breast fed till 1 month. Insufficient milk was an important reason for discontinuation before 6 months.  相似文献   
65.
66.

Background  

Traumatic perforation of the distal oesophagus due to blunt trauma is a very rare condition and is still associated with a significant morbidity and mortality. This is further exacerbated by delayed diagnosis and management as symptoms and signs are often masked by or ascribed to more common blunt thoracic injuries.  相似文献   
67.
OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.  相似文献   
68.
The main objective of this study was to examine the psychosocial stress model developed by Taylor and Aspinwall with emotional exhaustion as the outcome variable. Respondents, 409 men and 346 women, who had a paid job for at least 20 hours per week, completed questionnaires concerning demographic variables, personality, temperament, work pressure, workload, perceived social support, appraisal, coping, and emotional exhaustion. Structural equation analyses provided only partial support for the validity of the model. First, on theoretical and statistical grounds, one more path linking external resources to social support was added. Second, contrary to expectations, coping styles did not predict emotional exhaustion. To conclude, when coping is measured retrospectively, it does not add to our understanding of emotional exhaustion. It is suggested that future studies should be longitudinal and include objective measures of stressors and psychosocial health outcomes in addition to self‐reports. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
69.
Background: Postoperative pain mostly results from sensitization of afferent fibers at injury sites driving central sensitization. Recently, peripheral processes have gained attention as mechanisms of hyperalgesia, and prostaglandins are among highly sensitizing agents. To date, perioperative administration of a single local dose of nonsteroidal antiinflammatory drugs has shown inconclusive efficacy. Rather than a single bolus, the current study evaluates the postoperative analgesic effect of diclofenac continuous intrawound infusion after elective cesarean delivery.

Methods: Ninety-two parturients were randomly allocated to receive a 48-h continuous intrawound infusion with 240 ml containing 300 mg diclofenac, 0.2% ropivacaine, or saline. In the ropivacaine and saline groups, patients also received 75 mg intravenous diclofenac every 12 h for 48 h. Postoperative evaluation included intravenous morphine consumption by patient-controlled analgesia and visual analog pain scores. Punctate mechanical hyperalgesia surrounding the wound and presence of residual pain after 1 and 6 months were also assessed.

Results: Continuous diclofenac infusion significantly reduced postoperative morphine consumption (18 mg; 95% confidence interval, 12.7-22.2) in comparison with saline infusion and systemic diclofenac (38 mg; 95% confidence interval, 28.8-43.7) (P = 0.0009) without unique adverse effects. Postoperative analgesia produced by local diclofenac infusion was as effective as local ropivacaine infusion with systemic diclofenac.  相似文献   

70.
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