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   4020940篇
  免费   284209篇
  国内免费   9068篇
耳鼻咽喉   55866篇
儿科学   131687篇
妇产科学   110612篇
基础医学   573571篇
口腔科学   112030篇
临床医学   370195篇
内科学   775677篇
皮肤病学   92906篇
神经病学   325833篇
特种医学   152091篇
外国民族医学   1141篇
外科学   600580篇
综合类   83658篇
现状与发展   15篇
一般理论   1602篇
预防医学   314690篇
眼科学   93670篇
药学   296191篇
  16篇
中国医学   7855篇
肿瘤学   214331篇
  2019年   32270篇
  2018年   44633篇
  2017年   33831篇
  2016年   38896篇
  2015年   43810篇
  2014年   61187篇
  2013年   92677篇
  2012年   124879篇
  2011年   132604篇
  2010年   79755篇
  2009年   75850篇
  2008年   124134篇
  2007年   131964篇
  2006年   133893篇
  2005年   129214篇
  2004年   124330篇
  2003年   119843篇
  2002年   115904篇
  2001年   183132篇
  2000年   187981篇
  1999年   158938篇
  1998年   47195篇
  1997年   41478篇
  1996年   41630篇
  1995年   40015篇
  1994年   36754篇
  1993年   34577篇
  1992年   124643篇
  1991年   120825篇
  1990年   117519篇
  1989年   113905篇
  1988年   104818篇
  1987年   102725篇
  1986年   96723篇
  1985年   92700篇
  1984年   69302篇
  1983年   59004篇
  1982年   35179篇
  1981年   31680篇
  1979年   62893篇
  1978年   44726篇
  1977年   37765篇
  1976年   35547篇
  1975年   37967篇
  1974年   45286篇
  1973年   43149篇
  1972年   40610篇
  1971年   38143篇
  1970年   35121篇
  1969年   33800篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
BackgroundSecond-hand smoking or environmental tobacco smoke is a critical health risk. Children are the most vulnerable to second-hand smoking because of their small bronchial ducts, less developed immunity, and low-physical activity.ObjectivesThe purpose of this study was to ascertain the effects of second-hand smoking on lung functions in athlete and non-athlete school-aged children.MethodsThis observational study included forty-six school-aged children, their age was 8–15 years, assigned to three groups; 2 study groups and 1 control group (n=15). The study groups comprised of 16 football players, and of 15 cyclists. Lung functions were evaluated recording forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow using digital spirometer.ResultsAll measures were recorded in definite values and the children were also classified into second-hand smoking (SH), or non-exposed to tobacco smoking (NE). The findings presented a significant increase (p<0.05) of the study groups in forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow solely for the non-exposed children. However, there were non-significant differences between the cyclists and football players or between the passive smoking children and non-exposed children in any of the two study groups (p>0.05).ConclusionThe outcomes of this study suggest beneficial influences of the sports activity on the lung functions, without different influences of the cyclists and football players on the lung functions.  相似文献   
55.
56.
57.
58.
59.
Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies.  相似文献   
60.
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.  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