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   1547篇
  免费   122篇
  国内免费   15篇
耳鼻咽喉   10篇
儿科学   114篇
妇产科学   23篇
基础医学   225篇
口腔科学   36篇
临床医学   160篇
内科学   344篇
皮肤病学   50篇
神经病学   63篇
特种医学   150篇
外科学   116篇
综合类   40篇
预防医学   91篇
眼科学   78篇
药学   106篇
中国医学   3篇
肿瘤学   75篇
  2021年   22篇
  2020年   15篇
  2019年   26篇
  2018年   22篇
  2017年   29篇
  2016年   24篇
  2015年   43篇
  2014年   40篇
  2013年   71篇
  2012年   51篇
  2011年   52篇
  2010年   67篇
  2009年   60篇
  2008年   53篇
  2007年   62篇
  2006年   47篇
  2005年   45篇
  2004年   27篇
  2003年   24篇
  2002年   36篇
  2001年   18篇
  2000年   34篇
  1999年   35篇
  1998年   49篇
  1997年   45篇
  1996年   43篇
  1995年   25篇
  1994年   36篇
  1993年   33篇
  1992年   25篇
  1991年   23篇
  1990年   30篇
  1989年   40篇
  1988年   34篇
  1987年   32篇
  1986年   31篇
  1985年   43篇
  1984年   16篇
  1983年   24篇
  1982年   20篇
  1981年   14篇
  1980年   16篇
  1979年   13篇
  1977年   17篇
  1976年   11篇
  1975年   11篇
  1974年   12篇
  1970年   14篇
  1969年   13篇
  1967年   14篇
排序方式: 共有1684条查询结果,搜索用时 15 毫秒
1.
2.
3.
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.  相似文献   
4.
2-Nitro-oxaphenalenes are synthetic chemicals which were synthesized in the authors' laboratory. They are the most efficient mutagenic compounds on mammalian cells in culture. They are chemically related to the nitro-naphthofuran family by the displacement of the heterocycle on the naphthalene ring. Since nitro-naphthofurans have a strong mutagenic activity in bacterial tests without metabolic activation and are active in-vivo carcinogens, the purpose of this study was to demonstrate the carcinogenic activity of two 2-nitro-oxaphenalenes. The two compounds were injected s.c. into Wistar rats initially 6-weeks-old. They were dissolved in dimethylsulfoxide (DMSO) at a concentration of 1 mg/ml. A s.c. injection of 0.5 ml containing 0.5 mg of carcinogen was given once a week in the neck of each animal tested. Five control animals were not injected and five animals received 0.5-ml injection of DMSO every week to serve as a control. The animals developed tumors only at the site of injection. The tumors were classified as high grade fibrosarcomas. This experiment demonstrates that: (i) 2-nitro-oxaphenalenes are very active in-vivo carcinogens in rats; (ii) there is a good correlation between the high mutagenic activity especially in mammalian tests and the strong carcinogenicity of the compounds; and (iii) the presence of a 6-methoxy group increases by two-fold the carcinogenic potential.  相似文献   
5.
6.
7.
8.
9.
Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with CF. No significant association was found.  相似文献   
10.
Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced thoracic cavity. In the most common subtype (TD1), femurs are curved, while in TD2, straight femurs are associated with cloverleaf skull. Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene were identified in both subtypes. While TD2 was accounted for by a single recurrent mutation in the tyrosine kinase 2 domain, TD1 resulted from either stop codon mutations or missense mutations in the extracellular domain of the gene. Here, we report the identification of FGFR3 mutations in 25/26 TD cases. Two novel missense mutations (Y373C and G370C) were detected in 8/26 and 1/26 TD1 cases respectively. Both mutations created cysteine residues in the juxta extramembrane domain of the receptor. Sixteen cases carried the previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically homogeneous condition and give additional support to the view that newly created cysteine residues in the extracellular domain of the protein play a key role in the severity of the disease.   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