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   38603篇
  免费   2621篇
  国内免费   168篇
耳鼻咽喉   390篇
儿科学   1018篇
妇产科学   1091篇
基础医学   5722篇
口腔科学   1994篇
临床医学   3312篇
内科学   8487篇
皮肤病学   1207篇
神经病学   3474篇
特种医学   691篇
外国民族医学   1篇
外科学   3647篇
综合类   176篇
一般理论   26篇
预防医学   4197篇
眼科学   669篇
药学   2881篇
中国医学   202篇
肿瘤学   2207篇
  2024年   44篇
  2023年   424篇
  2022年   929篇
  2021年   1693篇
  2020年   957篇
  2019年   1422篇
  2018年   1724篇
  2017年   1151篇
  2016年   1114篇
  2015年   1382篇
  2014年   1795篇
  2013年   2198篇
  2012年   3328篇
  2011年   3509篇
  2010年   1793篇
  2009年   1524篇
  2008年   2471篇
  2007年   2425篇
  2006年   2105篇
  2005年   1857篇
  2004年   1617篇
  2003年   1379篇
  2002年   1197篇
  2001年   322篇
  2000年   292篇
  1999年   293篇
  1998年   195篇
  1997年   195篇
  1996年   141篇
  1995年   112篇
  1994年   109篇
  1993年   80篇
  1992年   168篇
  1991年   147篇
  1990年   131篇
  1989年   122篇
  1988年   137篇
  1987年   103篇
  1986年   109篇
  1985年   78篇
  1984年   68篇
  1983年   52篇
  1982年   45篇
  1981年   38篇
  1980年   39篇
  1979年   41篇
  1978年   31篇
  1976年   40篇
  1974年   43篇
  1973年   31篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
3.
4.
5.
6.
7.
8.
The yeast Saccharomyces cerevisiae is a useful model for studying the influence of different stress factors on eukaryotic cells. In this work we used the pesticide imidacloprid, in the Confidor formulation, as the stress factor and analyzed its influence on the metabolic activity, proteome and lipid content and composition of Saccharomyces cerevisiae yeast. During the cultivation of yeast, the lowest recommended application dose of Confidor (0.025%, v/v) was added to the growth media and its influence on the mitochondria, cytosol with microsomes, and the whole yeast cells was monitored. The results show that under the stress provoked by the toxic effects of Confidor, yeast cells density significantly decreased and the percentage of metabolically disturbed cells significantly increased comparing with untreated control. Also, there was a downregulation of majority of glycolytic, gluconeogenesis, and TCA cycle enzymes (Fba1, Adh1, Hxk2, Tal1, Tdh1,Tdh3, Eno1) thus providing enough acetyl‐CoA for the lipid restructuring and accumulation mechanism since we have found the changes in the cell and mitochondrial lipid content and FA composition. This data suggest that lipids could be the molecules that orchestrate the answer of the cells in the stress response to the Confidor treatment.  相似文献   
9.
We present a 6‐year‐old girl with skin hyperpigmentation, leukoplakia, and onychodystrophy, the classic mucocutaneous triad usually associated with dyskeratosis congenita. The patient also had premature graying of the hair, bone marrow failure, hepatitis, exudative retinopathy, osteopenia with multiple long bone fractures, and intracranial calcifications and brain cysts. Coats plus syndrome is a rare disease with a clinical and genetic overlap with dyskeratosis congenita. This disease is reviewed, with a focus on the pathogenesis of the genetic anomalies and its background as a telomere biology disorder.  相似文献   
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