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   195篇
  免费   0篇
  国内免费   3篇
系统科学   3篇
教育与普及   1篇
理论与方法论   2篇
现状及发展   49篇
研究方法   15篇
综合类   124篇
自然研究   4篇
  2018年   2篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   1篇
  2012年   9篇
  2011年   15篇
  2010年   4篇
  2009年   1篇
  2008年   9篇
  2007年   5篇
  2006年   13篇
  2005年   8篇
  2004年   10篇
  2003年   6篇
  2002年   7篇
  2001年   8篇
  2000年   7篇
  1999年   5篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   6篇
  1989年   2篇
  1988年   5篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1979年   1篇
  1978年   2篇
  1977年   3篇
  1976年   3篇
  1974年   2篇
  1973年   1篇
  1971年   7篇
  1970年   8篇
  1969年   5篇
  1968年   3篇
  1967年   3篇
  1966年   7篇
  1965年   3篇
  1963年   1篇
  1958年   1篇
  1956年   1篇
排序方式: 共有198条查询结果,搜索用时 31 毫秒
41.
42.
Cloning of the T gene required in mesoderm formation in the mouse   总被引:46,自引:0,他引:46  
B G Herrmann  S Labeit  A Poustka  T R King  H Lehrach 《Nature》1990,343(6259):617-622
The murine developmental mutation T identifies an essential gene in mesoderm formation. Embryos lacking normal gene activity fail to form the notochord, the entire posterior region and the allantois, and die at about 10 days of gestation. We have isolated the T gene using a combination of molecular and genetic techniques, thus making molecular tools available to study processes underlying mesoderm formation in the mouse.  相似文献   
43.
Correlation of DNA adduct levels in human lung with cigarette smoking   总被引:8,自引:0,他引:8  
D H Phillips  A Hewer  C N Martin  R C Garner  M M King 《Nature》1988,336(6201):790-792
Lung cancer is the most common cancer in men in the United Kingdom and the second most common in women, accounting for between 25 and 40% of all cancer deaths. Cigarette smoking is widely accepted as the major cause of lung cancer and linear relationships have been established between the number of cigarettes smoked and lung cancer risk. Although approximately 50 carcinogenic chemicals have been identified in cigarette smoke, a causal link between specific compounds and lung cancer has yet to be made. Studies on cigarette smokers' urine, blood and placenta have provided indications of carcinogen exposure, and although the presence of covalently-bound adducts in human DNA provides evidence of exposure to carcinogens, there have been no reports of systematic studies on the levels of DNA adducts in human lung. We report here, using the 32P-post-labelling technique, that cigarette smokers have higher adduct levels than non-smokers, that there is a linear relationship between adduct levels and daily or lifetime cigarette consumption, and that people who have given up smoking for at least five years have adduct levels similar to those of non-smokers.  相似文献   
44.
This article outlines the methodology and results of the Department of the Environment, Transport and the Regions (DETR) 1996-based household projections for England, and its regions. It examines differences between this round of projections and the previous 1992-based round. The 1996-based projections indicate that between 1996 and 2021 a growth of 3.8 million households can be expected in England, if recent trends continue. Both the national and subnational methodology and results are covered.  相似文献   
45.
Ellis-van Creveld syndrome (EvC, MIM 225500) is an autosomal recessive skeletal dysplasia characterized by short limbs, short ribs, postaxial polydactyly and dysplastic nails and teeth. Congenital cardiac defects, most commonly a defect of primary atrial septation producing a common atrium, occur in 60% of affected individuals. The disease was mapped to chromosome 4p16 in nine Amish subpedigrees and single pedigrees from Mexico, Ecuador and Brazil. Weyers acrodental dysostosis (MIM 193530), an autosomal dominant disorder with a similar but milder phenotype, has been mapped in a single pedigree to an area including the EvC critical region. We have identified a new gene (EVC), encoding a 992-amino-acid protein, that is mutated in individuals with EvC. We identified a splice-donor change in an Amish pedigree and six truncating mutations and a single amino acid deletion in seven pedigrees. The heterozygous carriers of these mutations did not manifest features of EvC. We found two heterozygous missense mutations associated with a phenotype, one in a man with Weyers acrodental dysostosis and another in a father and his daughter, who both have the heart defect characteristic of EvC and polydactyly, but not short stature. We suggest that EvC and Weyers acrodental dysostosis are allelic conditions.  相似文献   
46.
47.
H F Dylla  J H Abrams  C T Hovland  J G King 《Nature》1981,291(5814):401-404
  相似文献   
48.
49.
Turnover of basic protein of rat brain   总被引:7,自引:0,他引:7  
J G Wood  N King 《Nature》1971,229(5279):56-58
  相似文献   
50.
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