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   25072篇
  免费   1660篇
  国内免费   135篇
耳鼻咽喉   301篇
儿科学   545篇
妇产科学   474篇
基础医学   3502篇
口腔科学   646篇
临床医学   2143篇
内科学   5675篇
皮肤病学   338篇
神经病学   2401篇
特种医学   999篇
外科学   3376篇
综合类   262篇
一般理论   48篇
预防医学   1928篇
眼科学   1139篇
药学   1594篇
中国医学   52篇
肿瘤学   1444篇
  2023年   96篇
  2022年   199篇
  2021年   558篇
  2020年   285篇
  2019年   419篇
  2018年   568篇
  2017年   430篇
  2016年   516篇
  2015年   546篇
  2014年   801篇
  2013年   1053篇
  2012年   1635篇
  2011年   1680篇
  2010年   986篇
  2009年   909篇
  2008年   1523篇
  2007年   1582篇
  2006年   1409篇
  2005年   1462篇
  2004年   1297篇
  2003年   1222篇
  2002年   1202篇
  2001年   294篇
  2000年   270篇
  1999年   314篇
  1998年   260篇
  1997年   266篇
  1996年   212篇
  1995年   182篇
  1994年   134篇
  1993年   140篇
  1992年   195篇
  1991年   180篇
  1990年   185篇
  1989年   133篇
  1988年   144篇
  1987年   145篇
  1986年   151篇
  1985年   153篇
  1984年   164篇
  1983年   156篇
  1982年   153篇
  1981年   174篇
  1980年   146篇
  1979年   123篇
  1978年   110篇
  1977年   108篇
  1975年   112篇
  1974年   101篇
  1973年   120篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
4.
5.
6.
Reactive lymphoid infiltrates of the skin composed predominantly of gamma‐delta (γδ) T cells are not well described in the literature. Herein we report a case of an otherwise healthy 4‐year‐old male who presented with a waxing and waning papular rash characterized by small, discrete crusted papules spread across his trunk, face and extremities. Clinical evaluation revealed no evidence of systemic disease. Microscopic examination revealed a dermal, perivascular infiltrate of highly atypical lymphocytes with a γδ T cell phenotype, worrisome for primary cutaneous γδ T cell lymphoma. The clinical course, however, was that of a reactive condition and prompted consideration of a diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP). In many ways, this case defies current classification schemes and seems to expand the spectrum of reactive γδ T cell infiltrates of the skin.  相似文献   
7.
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a...  相似文献   
8.
In May 2017, the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee hosted a workshop to discuss whether mode of action (MOA) investigation is enhanced through the application of the adverse outcome pathway (AOP) framework. As AOPs are a relatively new approach in genetic toxicology, this report describes how AOPs could be harnessed to advance MOA analysis of genotoxicity pathways using five example case studies. Each of these genetic toxicology AOPs proposed for further development includes the relevant molecular initiating events, key events, and adverse outcomes (AOs), identification and/or further development of the appropriate assays to link an agent to these events, and discussion regarding the biological plausibility of the proposed AOP. A key difference between these proposed genetic toxicology AOPs versus traditional AOPs is that the AO is a genetic toxicology endpoint of potential significance in risk characterization, in contrast to an adverse state of an organism or a population. The first two detailed case studies describe provisional AOPs for aurora kinase inhibition and tubulin binding, leading to the common AO of aneuploidy. The remaining three case studies highlight provisional AOPs that lead to chromosome breakage or mutation via indirect DNA interaction (inhibition of topoisomerase II, production of cellular reactive oxygen species, and inhibition of DNA synthesis). These case studies serve as starting points for genotoxicity AOPs that could ultimately be published and utilized by the broader toxicology community and illustrate the practical considerations and evidence required to formalize such AOPs so that they may be applied to genetic toxicity evaluation schemes. Environ. Mol. Mutagen. 61:114–134, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
9.
10.
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