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   1565818篇
  免费   126414篇
  国内免费   4189篇
耳鼻咽喉   20003篇
儿科学   51035篇
妇产科学   44654篇
基础医学   223141篇
口腔科学   41858篇
临床医学   139606篇
内科学   316854篇
皮肤病学   36009篇
神经病学   131848篇
特种医学   60144篇
外国民族医学   489篇
外科学   231248篇
综合类   34644篇
现状与发展   4篇
一般理论   601篇
预防医学   124767篇
眼科学   34134篇
药学   109669篇
  3篇
中国医学   3988篇
肿瘤学   91722篇
  2021年   13673篇
  2019年   14370篇
  2018年   19852篇
  2017年   15335篇
  2016年   17167篇
  2015年   19340篇
  2014年   27084篇
  2013年   39485篇
  2012年   54323篇
  2011年   56998篇
  2010年   33442篇
  2009年   32152篇
  2008年   52438篇
  2007年   55130篇
  2006年   55293篇
  2005年   53377篇
  2004年   50979篇
  2003年   48659篇
  2002年   46823篇
  2001年   78120篇
  2000年   79581篇
  1999年   65899篇
  1998年   18927篇
  1997年   16985篇
  1996年   17045篇
  1995年   16097篇
  1994年   14601篇
  1993年   13665篇
  1992年   48698篇
  1991年   46171篇
  1990年   43941篇
  1989年   41966篇
  1988年   38389篇
  1987年   37301篇
  1986年   34759篇
  1985年   33046篇
  1984年   25136篇
  1983年   21212篇
  1982年   12925篇
  1981年   11394篇
  1979年   21738篇
  1978年   15256篇
  1977年   12684篇
  1976年   11875篇
  1975年   12221篇
  1974年   14698篇
  1973年   14235篇
  1972年   13242篇
  1971年   12054篇
  1970年   11407篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
64.

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   
65.
66.
67.
68.
69.
70.
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