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   38187篇
  免费   2476篇
  国内免费   199篇
耳鼻咽喉   401篇
儿科学   962篇
妇产科学   953篇
基础医学   5614篇
口腔科学   2374篇
临床医学   3270篇
内科学   8625篇
皮肤病学   1171篇
神经病学   3457篇
特种医学   616篇
外科学   3071篇
综合类   166篇
一般理论   22篇
预防医学   4207篇
眼科学   610篇
药学   2922篇
中国医学   224篇
肿瘤学   2197篇
  2024年   52篇
  2023年   488篇
  2022年   1068篇
  2021年   1880篇
  2020年   1078篇
  2019年   1544篇
  2018年   1821篇
  2017年   1211篇
  2016年   1190篇
  2015年   1472篇
  2014年   1918篇
  2013年   2340篇
  2012年   3542篇
  2011年   3702篇
  2010年   1858篇
  2009年   1517篇
  2008年   2554篇
  2007年   2428篇
  2006年   2067篇
  2005年   1862篇
  2004年   1586篇
  2003年   1351篇
  2002年   1142篇
  2001年   122篇
  2000年   68篇
  1999年   112篇
  1998年   160篇
  1997年   137篇
  1996年   91篇
  1995年   69篇
  1994年   73篇
  1993年   49篇
  1992年   49篇
  1991年   34篇
  1990年   27篇
  1989年   24篇
  1988年   16篇
  1987年   19篇
  1986年   15篇
  1985年   12篇
  1984年   13篇
  1983年   12篇
  1982年   15篇
  1981年   9篇
  1980年   13篇
  1978年   8篇
  1976年   6篇
  1975年   7篇
  1973年   5篇
  1972年   5篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
1.
2.
3.
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   
4.
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