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   46931篇
  免费   2913篇
  国内免费   206篇
耳鼻咽喉   494篇
儿科学   1260篇
妇产科学   1143篇
基础医学   6912篇
口腔科学   2449篇
临床医学   4534篇
内科学   9995篇
皮肤病学   1268篇
神经病学   4189篇
特种医学   822篇
外科学   3826篇
综合类   252篇
一般理论   29篇
预防医学   5450篇
眼科学   811篇
药学   3549篇
中国医学   255篇
肿瘤学   2812篇
  2024年   58篇
  2023年   524篇
  2022年   1156篇
  2021年   2070篇
  2020年   1168篇
  2019年   1734篇
  2018年   2046篇
  2017年   1386篇
  2016年   1351篇
  2015年   1668篇
  2014年   2179篇
  2013年   2718篇
  2012年   4163篇
  2011年   4434篇
  2010年   2204篇
  2009年   1891篇
  2008年   3155篇
  2007年   3022篇
  2006年   2715篇
  2005年   2427篇
  2004年   2114篇
  2003年   1855篇
  2002年   1681篇
  2001年   220篇
  2000年   146篇
  1999年   174篇
  1998年   276篇
  1997年   219篇
  1996年   157篇
  1995年   124篇
  1994年   125篇
  1993年   102篇
  1992年   79篇
  1991年   68篇
  1990年   59篇
  1989年   43篇
  1988年   36篇
  1987年   43篇
  1986年   43篇
  1985年   35篇
  1984年   40篇
  1983年   40篇
  1982年   46篇
  1981年   35篇
  1980年   39篇
  1979年   21篇
  1978年   14篇
  1977年   13篇
  1976年   14篇
  1975年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
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   
5.
6.
7.
8.
9.
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   
10.
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   
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