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   2609592篇
  免费   189795篇
  国内免费   5922篇
耳鼻咽喉   37030篇
儿科学   83844篇
妇产科学   75881篇
基础医学   365791篇
口腔科学   75453篇
临床医学   227180篇
内科学   510697篇
皮肤病学   60452篇
神经病学   208959篇
特种医学   104213篇
外国民族医学   943篇
外科学   397497篇
综合类   58515篇
现状与发展   8篇
一般理论   864篇
预防医学   197204篇
眼科学   61083篇
药学   189521篇
  7篇
中国医学   5548篇
肿瘤学   144619篇
  2018年   28238篇
  2017年   22914篇
  2016年   24645篇
  2015年   28686篇
  2014年   38416篇
  2013年   55362篇
  2012年   78095篇
  2011年   78085篇
  2010年   45776篇
  2009年   45448篇
  2008年   71580篇
  2007年   77155篇
  2006年   78349篇
  2005年   83009篇
  2004年   81557篇
  2003年   74930篇
  2002年   69207篇
  2001年   121354篇
  2000年   123143篇
  1999年   105564篇
  1998年   28782篇
  1997年   25989篇
  1996年   25554篇
  1995年   24261篇
  1994年   22356篇
  1993年   20851篇
  1992年   82622篇
  1991年   79897篇
  1990年   77986篇
  1989年   75268篇
  1988年   69708篇
  1987年   68357篇
  1986年   65001篇
  1985年   61446篇
  1984年   46384篇
  1983年   39144篇
  1982年   23226篇
  1981年   20855篇
  1979年   43211篇
  1978年   30466篇
  1977年   25793篇
  1976年   23700篇
  1975年   26442篇
  1974年   31637篇
  1973年   30574篇
  1972年   29069篇
  1971年   27028篇
  1970年   25722篇
  1969年   24442篇
  1968年   23029篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
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   
73.
74.
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   
75.
76.

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   
77.
78.
79.
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