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   249514篇
  免费   40109篇
  国内免费   1634篇
耳鼻咽喉   4086篇
儿科学   6349篇
妇产科学   4884篇
基础医学   23081篇
口腔科学   8287篇
临床医学   40685篇
内科学   56496篇
皮肤病学   6460篇
神经病学   26053篇
特种医学   10305篇
外国民族医学   14篇
外科学   42041篇
综合类   2055篇
现状与发展   40篇
一般理论   109篇
预防医学   24561篇
眼科学   5335篇
药学   11065篇
中国医学   244篇
肿瘤学   19107篇
  2024年   803篇
  2023年   5725篇
  2022年   2496篇
  2021年   5850篇
  2020年   7145篇
  2019年   4969篇
  2018年   10144篇
  2017年   9799篇
  2016年   10715篇
  2015年   11242篇
  2014年   15025篇
  2013年   18425篇
  2012年   13674篇
  2011年   14108篇
  2010年   12744篇
  2009年   14636篇
  2008年   12873篇
  2007年   12279篇
  2006年   13323篇
  2005年   11986篇
  2004年   10557篇
  2003年   9570篇
  2002年   9158篇
  2001年   3955篇
  2000年   2981篇
  1999年   3784篇
  1998年   3915篇
  1997年   3371篇
  1996年   3221篇
  1995年   2871篇
  1994年   2171篇
  1993年   1913篇
  1992年   2046篇
  1991年   1826篇
  1990年   1554篇
  1989年   1493篇
  1988年   1413篇
  1987年   1276篇
  1986年   1257篇
  1985年   1179篇
  1984年   1194篇
  1983年   1106篇
  1982年   1191篇
  1981年   1072篇
  1980年   847篇
  1979年   731篇
  1978年   785篇
  1977年   662篇
  1976年   605篇
  1974年   607篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
101.
102.
103.

Background

The ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials showed that the adjuvanted recombinant zoster vaccine (RZV) was ≥90% efficacious in preventing herpes zoster in adults. Here we present a comprehensive overview of the safety data from these studies.

Methods

Adults aged ≥50 (ZOE-50) and ≥70 (ZOE-70) years were randomly vaccinated with RZV or placebo. Safety analyses were performed on the pooled total vaccinated cohort, consisting of participants receiving at least one dose of RZV or placebo. Solicited and unsolicited adverse events (AEs) were collected for 7 and 30?days after each vaccination, respectively. Serious AEs (SAEs) were collected from the first vaccination until 12?months post-last dose. Fatal AEs, vaccination-related SAEs, and potential immune-mediated diseases (pIMDs) were collected during the entire study period.

Results

Safety was evaluated in 14,645 RZV and 14,660 placebo recipients. More RZV than placebo recipients reported unsolicited AEs (50.5% versus 32.0%); the difference was driven by transient injection site and solicited systemic reactions that were generally seen in the first week post-vaccination. The occurrence of overall SAEs (RZV: 10.1%; Placebo: 10.4%), fatal AEs (RZV: 4.3%; Placebo: 4.6%), and pIMDs (RZV: 1.2%; Placebo: 1.4%) was balanced between groups. The occurrence of possible exacerbations of pIMDs was rare and similar between groups. Overall, except for the expected local and systemic symptoms, the safety results were comparable between the RZV and Placebo groups irrespective of participant age, gender, or race.

Conclusions

No safety concerns arose, supporting the favorable benefit-risk profile of RZV.  相似文献   
104.
Immune defenses provide resistance against infectious disease that is critical to survival. But immune defenses are costly, and limited resources allocated to immunity are not available for other physiological or developmental processes. We propose a framework for explaining variation in patterns of investment in two important subsystems of anti-pathogen defense: innate (non-specific) and acquired (specific) immunity. The developmental costs of acquired immunity are high, but the costs of maintenance and activation are relatively low. Innate immunity imposes lower upfront developmental costs, but higher operating costs. Innate defenses are mobilized quickly and are effective against novel pathogens. Acquired responses are less effective against novel exposures, but more effective against secondary exposures due to immunological memory. Based on their distinct profiles of costs and effectiveness, we propose that the balance of investment in innate versus acquired immunity is variable, and that this balance is optimized in response to local ecological conditions early in development. Nutritional abundance, high pathogen exposure and low signals of extrinsic mortality risk during sensitive periods of immune development should all favor relatively higher levels of investment in acquired immunity. Undernutrition, low pathogen exposure, and high mortality risk should favor innate immune defenses. The hypothesis provides a framework for organizing prior empirical research on the impact of developmental environments on innate and acquired immunity, and suggests promising directions for future research in human ecological immunology.  相似文献   
105.
106.
107.
108.
Gray platelet syndrome (GPS) is a rare (<1/1 000 000) and inherited platelet function disorder characterized by macrothrombocytopenia, α-granule deficiency, and hemorrhages. Bleeding intensity does not correlate with platelet count nor with functional test results. We hereby describe the perioperative bleeding prevention and management of a patient with GPS requiring multiple redo cardiac surgeries.  相似文献   
109.
We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa’s environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly.  相似文献   
110.
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