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   1573542篇
  免费   116740篇
  国内免费   3351篇
耳鼻咽喉   19434篇
儿科学   52927篇
妇产科学   43993篇
基础医学   216245篇
口腔科学   39224篇
临床医学   137397篇
内科学   313209篇
皮肤病学   34025篇
神经病学   132205篇
特种医学   62322篇
外国民族医学   464篇
外科学   237685篇
综合类   35122篇
现状与发展   3篇
一般理论   488篇
预防医学   126569篇
眼科学   34282篇
药学   107665篇
  1篇
中国医学   3988篇
肿瘤学   96385篇
  2021年   10977篇
  2019年   11763篇
  2018年   37002篇
  2017年   28742篇
  2016年   32407篇
  2015年   16945篇
  2014年   23413篇
  2013年   34221篇
  2012年   52073篇
  2011年   67714篇
  2010年   45692篇
  2009年   37928篇
  2008年   62512篇
  2007年   67069篇
  2006年   47977篇
  2005年   47952篇
  2004年   47057篇
  2003年   45870篇
  2002年   42591篇
  2001年   73299篇
  2000年   74969篇
  1999年   61763篇
  1998年   17208篇
  1997年   15634篇
  1996年   15678篇
  1995年   14896篇
  1994年   13504篇
  1993年   12643篇
  1992年   45905篇
  1991年   43594篇
  1990年   41645篇
  1989年   39673篇
  1988年   36270篇
  1987年   35439篇
  1986年   32908篇
  1985年   31349篇
  1984年   23859篇
  1983年   20066篇
  1982年   12244篇
  1981年   10790篇
  1979年   20730篇
  1978年   14606篇
  1977年   12106篇
  1976年   11392篇
  1975年   11644篇
  1974年   14025篇
  1973年   13554篇
  1972年   12652篇
  1971年   11481篇
  1970年   10940篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
52.
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   
53.
54.
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   
55.
56.

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   
57.
58.
59.
60.
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