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   2150218篇
  免费   165463篇
  国内免费   4335篇
耳鼻咽喉   29237篇
儿科学   65915篇
妇产科学   59069篇
基础医学   305355篇
口腔科学   61463篇
临床医学   191035篇
内科学   426071篇
皮肤病学   48522篇
神经病学   173754篇
特种医学   82745篇
外国民族医学   536篇
外科学   332553篇
综合类   46759篇
现状与发展   4篇
一般理论   678篇
预防医学   159846篇
眼科学   49224篇
药学   157450篇
  4篇
中国医学   4842篇
肿瘤学   124954篇
  2019年   15968篇
  2018年   23025篇
  2017年   17727篇
  2016年   19888篇
  2015年   22414篇
  2014年   31267篇
  2013年   46576篇
  2012年   63183篇
  2011年   66641篇
  2010年   39317篇
  2009年   37763篇
  2008年   63004篇
  2007年   66457篇
  2006年   67545篇
  2005年   65363篇
  2004年   62671篇
  2003年   60047篇
  2002年   58349篇
  2001年   114308篇
  2000年   117256篇
  1999年   97372篇
  1998年   25484篇
  1997年   22793篇
  1996年   22932篇
  1995年   21677篇
  1994年   19788篇
  1993年   18469篇
  1992年   73953篇
  1991年   70758篇
  1990年   68064篇
  1989年   65614篇
  1988年   60086篇
  1987年   58645篇
  1986年   54602篇
  1985年   52319篇
  1984年   38692篇
  1983年   32633篇
  1982年   18626篇
  1981年   16400篇
  1979年   34125篇
  1978年   23512篇
  1977年   19818篇
  1976年   18036篇
  1975年   19016篇
  1974年   23070篇
  1973年   22064篇
  1972年   20769篇
  1971年   19214篇
  1970年   18314篇
  1969年   17078篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
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   
73.
74.

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   
75.
76.
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