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   1865113篇
  免费   140231篇
  国内免费   15247篇
耳鼻咽喉   22608篇
儿科学   57694篇
妇产科学   48199篇
基础医学   254012篇
口腔科学   44401篇
临床医学   171655篇
内科学   362096篇
皮肤病学   37768篇
神经病学   151915篇
特种医学   72409篇
外国民族医学   565篇
外科学   273500篇
综合类   66026篇
现状与发展   43篇
一般理论   666篇
预防医学   148892篇
眼科学   41253篇
药学   134518篇
  192篇
中国医学   14917篇
肿瘤学   117262篇
  2022年   12462篇
  2021年   22036篇
  2020年   15091篇
  2019年   19442篇
  2018年   46159篇
  2017年   37004篇
  2016年   41155篇
  2015年   27376篇
  2014年   36425篇
  2013年   47878篇
  2012年   71794篇
  2011年   90061篇
  2010年   59485篇
  2009年   49512篇
  2008年   80470篇
  2007年   86174篇
  2006年   63621篇
  2005年   64302篇
  2004年   60192篇
  2003年   58989篇
  2002年   54156篇
  2001年   77326篇
  2000年   79079篇
  1999年   66162篇
  1998年   20846篇
  1997年   19149篇
  1996年   18361篇
  1995年   17532篇
  1994年   15809篇
  1993年   14381篇
  1992年   47620篇
  1991年   45113篇
  1990年   42929篇
  1989年   40875篇
  1988年   37362篇
  1987年   36391篇
  1986年   33791篇
  1985年   32259篇
  1984年   24698篇
  1983年   20907篇
  1982年   13333篇
  1981年   11774篇
  1979年   21274篇
  1978年   15162篇
  1977年   12591篇
  1976年   11843篇
  1975年   11991篇
  1974年   14340篇
  1973年   13830篇
  1972年   12830篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
孤独症谱系障碍(ASD)是影响儿童健康的严重公共问题之一,以社交沟通障碍、兴趣或活动范围狭窄以及重复刻板行为为特征。近年来越来越多的研究显示,ASD患儿维生素D(VitD)水平明显低于同龄健康儿童,VitD缺乏可能与ASD的发病机制相关。本文就VitD与ASD的相关研究进行综述。  相似文献   
82.
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   
83.
84.
AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXsmiR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXsmiR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.  相似文献   
85.
86.

Researchers have highlighted numerous sociocultural factors that have been shown to underpin human appearance enhancement practices, including the influence of peers, family, the media, and sexual objectification. Fewer scholars have approached appearance enhancement from an evolutionary perspective or considered how sociocultural factors interact with evolved psychology to produce appearance enhancement behavior. Following others, we argue that evidence from the field of evolutionary psychology can complement existing sociocultural models by yielding unique insight into the historical and cross-cultural ubiquity of competition over aspects of physical appearance to embody what is desired by potential mates. An evolutionary lens can help to make sense of reliable sex and individual differences that impact appearance enhancement, as well as the context-dependent nature of putative adaptations that function to increase physical attractiveness. In the current review, appearance enhancement is described as a self-promotion strategy used to enhance reproductive success by rendering oneself more attractive than rivals to mates, thereby increasing one’s mate value. The varied ways in which humans enhance their appearance are described, as well as the divergent tactics used by women and men to augment their appearance, which correspond to the preferences of opposite-sex mates in a heterosexual context. Evolutionarily relevant individual differences and contextual factors that vary predictably with appearance enhancement behavior are also discussed. The complementarity of sociocultural and evolutionary perspectives is emphasized and recommended avenues for future interdisciplinary research are provided for scholars interested in studying appearance enhancement behavior.

  相似文献   
87.
88.
89.
90.
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