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   1245717篇
  免费   105327篇
  国内免费   3713篇
耳鼻咽喉   19947篇
儿科学   40539篇
妇产科学   31542篇
基础医学   160795篇
口腔科学   32166篇
临床医学   123286篇
内科学   253903篇
皮肤病学   32112篇
神经病学   98596篇
特种医学   50419篇
外国民族医学   201篇
外科学   206242篇
综合类   22085篇
现状与发展   72篇
一般理论   286篇
预防医学   83750篇
眼科学   27950篇
药学   89565篇
  7篇
中国医学   2861篇
肿瘤学   78433篇
  2021年   10688篇
  2020年   10982篇
  2019年   10354篇
  2018年   19125篇
  2017年   16679篇
  2016年   18827篇
  2015年   19884篇
  2014年   30741篇
  2013年   38806篇
  2012年   38268篇
  2011年   40105篇
  2010年   30052篇
  2009年   32178篇
  2008年   37801篇
  2007年   38282篇
  2006年   41080篇
  2005年   36720篇
  2004年   34466篇
  2003年   32293篇
  2002年   31344篇
  2001年   64296篇
  2000年   65072篇
  1999年   54440篇
  1998年   16143篇
  1997年   14518篇
  1996年   14362篇
  1995年   13549篇
  1994年   11328篇
  1993年   10455篇
  1992年   39189篇
  1991年   37766篇
  1990年   36880篇
  1989年   35527篇
  1988年   31960篇
  1987年   30910篇
  1986年   29189篇
  1985年   27329篇
  1984年   19865篇
  1983年   16724篇
  1982年   9415篇
  1979年   17396篇
  1978年   11791篇
  1977年   10667篇
  1976年   9119篇
  1975年   10379篇
  1974年   11900篇
  1973年   11534篇
  1972年   11044篇
  1971年   10307篇
  1970年   9511篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
72.
Clinical trials are probably the most informative experiments to help an understanding of multiple sclerosis (MS) biology. Recent successes with CD20‐depleting antibodies have focused attention towards B cell subsets as important mediators in MS. The trial of tabalumab (NTC00882999), which inhibits B cell activation factor (BAFF), is reported and reviewed and this trial is contrasted with the trial on the inhibition of a proliferation‐inducing ligand (APRIL) and BAFF using atacicept (NCT00642902). Both tabalumab and atacicept induce depletion of mature B cells and inhibit antibody formation, but they fail to deplete memory B cells and do not inhibit relapsing MS. Atacicept is reported to augment memory B cell responses and may precipitate relapse, suggesting the importance of APRIL. However, BAFF inhibition can enhance peripheral blood memory B cell responses, which was not associated with augmented relapse. Although other interpretations are possible, these data further support the hypothesis that memory B cells may be of central importance in relapsing MS, as they are the major CD20+ B cell subset expressing APRIL receptors. They also suggest that quantitative and/or qualitative differences in B cell responses or other factors, such as an immune‐regulatory effect associated with APRIL, may be important in determining whether MS reactivates following neutralization of peripheral B cell maturation and survival factors.  相似文献   
73.
74.
75.
76.
77.
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   
78.
79.
As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n > 400 total) examining the power of society’s widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which—notably—remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.  相似文献   
80.
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