全文获取类型
收费全文 | 211篇 |
免费 | 0篇 |
专业分类
系统科学 | 2篇 |
教育与普及 | 1篇 |
理论与方法论 | 6篇 |
现状及发展 | 102篇 |
研究方法 | 14篇 |
综合类 | 73篇 |
自然研究 | 13篇 |
出版年
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2013年 | 2篇 |
2012年 | 7篇 |
2011年 | 17篇 |
2010年 | 6篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1992年 | 8篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 8篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1970年 | 10篇 |
1969年 | 2篇 |
1968年 | 7篇 |
1967年 | 5篇 |
1966年 | 4篇 |
1965年 | 2篇 |
1963年 | 2篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1957年 | 3篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有211条查询结果,搜索用时 15 毫秒
101.
102.
X-irradiation of pregnant NMRI-mice on gestational days 11-13 with 3 x 10.5 Gy increased postnatal mortality of the female offspring only. Weights, protein content and acetylcholinesterase, as well as Na,K-ATPase activities in the brains of all treated offspring, were changed. There were, however, no differences between females and males with respect to these parameters. 相似文献
103.
To identify expressed sequences within candidate regions for the Huntington's disease (HD) gene in 4p16.3, we isolated the gene encoding the beta subunit of the human cGMP phosphodiesterase (PDEB). We formally assessed this as a candidate gene for HD based on it's expression in brain, the demonstration of linkage disequilibrium between intragenic DNA markers and HD, and the demonstration that mice with a mutation in this gene have a reduction of neurons in particular brain regions. We investigated all 22 exons of PDEB and 5'-flanking region for point mutations in 16 HD patients of different ethnic origins using single strand conformational polymorphism analysis. The underlying DNA changes found initially exclusively in HD patients were excluded as the cause for HD. 相似文献
104.
J M Weber 《Experientia》1992,48(6):557-564
The study of metabolic fuel provision and its regulation has reached an exciting stage where specific molecular events can be correlated with parameters of the organism's ecology. This paper examines substrate supply pathways from storage sites to locomotory muscle mitochondria and discusses ecological implications of the limits for maximal flux through these pathways. The relative importance of the different oxidative fuels is shown to depend on aerobic capacity. Very aerobic, endurance-adapted animals such as long distance migrants favor the use of lipids and intramuscular fuels over carbohydrates and circulatory fuels. The hypothesis of functional co-adaptation between oxygen and metabolic fuel supply systems allows us to predict that the capacity of several biochemical processes should be scaled with maximal oxygen consumption. Key enzymes, transmembrane transporter proteins, glucose precursor supply and soluble fatty acid transport proteins must all be geared to support higher maximal glucose and fatty acid fluxes in aerobic than in sedentary species. 相似文献
105.
The structure of the E. coli recA protein monomer and polymer. 总被引:20,自引:0,他引:20
The crystal structure of the recA protein from Escherichia coli at 2.3-A resolution reveals a major domain that binds ADP and probably single- and double-stranded DNA. Two smaller subdomains at the N and C termini protrude from the protein and respectively stabilize a 6(1) helical polymer of protein subunits and interpolymer bundles. This polymer structure closely resembles that of recA/DNA filaments determined by electron microscopy. Mutations in recA protein that enhance coprotease, DNA-binding and/or strand-exchange activity can be explained if the interpolymer interactions in the crystal reflect a regulatory mechanism in vivo. 相似文献
106.
Identification of foreign gene sequences by transcript filtering against the human genome. 总被引:5,自引:0,他引:5
Griffin Weber Jay Shendure David M Tanenbaum George M Church Matthew Meyerson 《Nature genetics》2002,30(2):141-142
We have developed a computational subtraction approach to detect microbial causes for putative infectious diseases by filtering a set of human tissue-derived sequences against the human genome. We demonstrate the potential of this method by identifying sequences from known pathogens in established expressed-sequence tag libraries. 相似文献
107.
108.
109.
110.