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   2430032篇
  免费   177269篇
  国内免费   5964篇
耳鼻咽喉   33020篇
儿科学   80050篇
妇产科学   68690篇
基础医学   356772篇
口腔科学   67962篇
临床医学   223176篇
内科学   468032篇
皮肤病学   49267篇
神经病学   198128篇
特种医学   91210篇
外国民族医学   715篇
外科学   352826篇
综合类   51454篇
现状与发展   3篇
一般理论   829篇
预防医学   198584篇
眼科学   54650篇
药学   181302篇
  7篇
中国医学   5220篇
肿瘤学   131368篇
  2018年   26939篇
  2017年   20443篇
  2016年   22611篇
  2015年   25859篇
  2014年   35671篇
  2013年   54525篇
  2012年   75209篇
  2011年   80050篇
  2010年   46795篇
  2009年   43692篇
  2008年   74780篇
  2007年   79630篇
  2006年   80278篇
  2005年   77887篇
  2004年   74134篇
  2003年   71070篇
  2002年   69245篇
  2001年   106372篇
  2000年   109025篇
  1999年   92400篇
  1998年   27021篇
  1997年   24292篇
  1996年   24259篇
  1995年   22857篇
  1994年   21479篇
  1993年   20076篇
  1992年   74063篇
  1991年   72841篇
  1990年   71165篇
  1989年   68389篇
  1988年   63530篇
  1987年   61989篇
  1986年   59230篇
  1985年   56657篇
  1984年   42537篇
  1983年   36593篇
  1982年   22036篇
  1981年   19554篇
  1979年   39622篇
  1978年   28026篇
  1977年   23635篇
  1976年   22709篇
  1975年   24146篇
  1974年   28880篇
  1973年   28145篇
  1972年   26458篇
  1971年   24582篇
  1970年   22854篇
  1969年   21495篇
  1968年   20367篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Rift Valley fever (RVF) virus infection, dissemination, and transmission rates were determined for Aedes fowleri, Aedes mcintoshi and Culex pipiens 7 or 10 days after sequentially feeding to repletion on RVF virus immune hamsters and RVF viremic hamsters, or after feeding on a mixture of RVF virus immune sheep serum and RVF viremic hamster blood through a pledget. No significant differences in infection or dissemination rates were detected among Ae. fowleri and Cx. pipiens feeding to repletion on immune hamsters before or after feeding to repletion on a viremic hamster. Similarly, no significant differences in infection, dissemination, or transmission rates were observed among Ae. fowleri and Cx. pipiens feeding to repletion on immune hamsters or nonimmune (control) hamsters 0 or 24 hr after inoculation with RVF virus. Infection rates were significantly higher for Ae. fowleri (56/66, 85%) and Cx. pipiens (123/148, 83%) fed only on viremic hamsters than for those interrupted to complete feeding on an immune hamster (Ae. fowleri [24/49, 59%], Cx. pipiens [66/131, 50%]) or a nonimmune hamster (Ae. fowleri [32/51, 63%], Cx. pipiens [69/127, 54%]). However, no significant differences were detected in infection, dissemination, or transmission rates among Ae. fowleri, Ae. mcintoshi or Cx. pipiens fed on a viremic hamster and interrupted to complete feeding on an immune vs. a nonimmune hamster. Results from interrupted feeding experiments were significantly different from pledget feeding experiments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
992.
A 41-year-old woman had acute hepatitis A infection complicated with severe anemia due to selective erythroblastopenia and hemolysis. A mechanism involving a cellular immune reaction is suggested. The hematological complications resolved during steroid treatment. She later developed a transient seropositive arthritis.  相似文献   
993.
To evaluate the use of pelvic ultrasonography in the diagnosis and management of female adolescents with pelvic inflammatory disease (PID), sonograms of 60 patients with PID were compared with those of 40 age-matched controls. Sonograms were evaluated for adnexal volume, adnexal adherence, uterine size, and the presence of cul-de-sac fluid. Eleven (19.3%) of the 57 patients with PID, in whom adequate sonograms were obtained, had tubo-ovarian abscesses; in seven of these patients, the abscesses were diagnosed ultrasonographically before suspected clinically. Even in those patients without tubo-ovarian abscesses, the mean (+/- SD) adnexal volume in the PID group was significantly larger than that of the control group (11.0 +/- 6.8 cm3 vs 5.2 +/- 2.7 cm,3 respectively). Adnexal adherence, uterine size, and the presence of cul-de-sac fluid were not useful in differentiating patients with PID from normal controls. Pelvic ultrasonography can be a useful adjunct in the diagnosis and management of PID in adolescents and may, in some instances, provide diagnoses in the absence of clinical findings.  相似文献   
994.
Bone and joint sepsis   总被引:1,自引:0,他引:1  
  相似文献   
995.
Preclinical and clinical investigations currently underway are employing novel strategies for combining vaccines with conventional and experimental anticancer therapies. To date, the FDA has not approved a therapeutic cancer vaccine. However, the results of recent investigations suggest an increasing role for vaccines in new models of combination therapy for many types of cancer. This article reviews and discusses therapeutic cancer strategies that employ vaccines in combination with local radiation, chemotherapy, hormone therapy, and anti-CTLA-4 mAb. Preclinical studies have shown that certain anticancer agents have immune modulatory effects that result in up-regulation of surface expression of MHC molecules, tumor-associated antigens, or Fas on malignant cells, rendering them more susceptible to immune destruction. Preliminary results of clinical studies using combination strategies have demonstrated a postvaccination antigen cascade, prolonged time to disease progression, and improved overall survival. Several larger randomized trials are ongoing, and more are required to support these findings.  相似文献   
996.
997.
The article presents an original method of laparoscopic anti-reflux surgery, immediate and long-term results of the treatment of 132 patients with esophageal opening hernia. It also describes the analysis of the life quality of patients with the gastroesophageal reflux disease before and after the surgery.  相似文献   
998.
999.
Diesters based on isosteviol and dicarboxylic acids were synthesized and tested for antituberculous activity. Isosteviol and some of its derivatives exhibit appreciable tuberculostatic properties in vitro, the activity being dependent on the length of the polymethylene spacer connecting two ent-beyeran fragments. The mechanism of the antituberculous action of isosteviol derivatives are discussed. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 9, pp. 12–13, September, 2006.  相似文献   
1000.
It is usual at the end of a year for top tens to feature large in our collective consciousness. These inevitably include the occasional controversial selection and without fail will overlook a number of gems, whether in the field of literature, art, or science. The approaches to such compilations include personal selections, convening expert committees through to letting the market decide. However, it is well recognised that experts can be wrong and markets distorted. A novel approach to identifying the key publications in the field of medicine, Faculty of 1000 Medicine (http://www.f1000medicine.com), uses faculty evaluations to assign ratings to published papers within topics and categories, bringing a flavour of the dynamism of post hoc peer review to biological sciences that exists in other fields of scholarship. Archives of Disease in Childhood has also developed a market led system of peer evaluation through its web based top ten most read articles feature.  相似文献   
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