全文获取类型
收费全文 | 146篇 |
免费 | 0篇 |
专业分类
教育与普及 | 1篇 |
现状及发展 | 31篇 |
研究方法 | 13篇 |
综合类 | 96篇 |
自然研究 | 5篇 |
出版年
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2008年 | 8篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 11篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 5篇 |
1967年 | 2篇 |
1966年 | 5篇 |
1965年 | 1篇 |
排序方式: 共有146条查询结果,搜索用时 265 毫秒
81.
Transposition of a tandem duplication of yeast mating-type genes 总被引:4,自引:0,他引:4
82.
Joron M Frezal L Jones RT Chamberlain NL Lee SF Haag CR Whibley A Becuwe M Baxter SW Ferguson L Wilkinson PA Salazar C Davidson C Clark R Quail MA Beasley H Glithero R Lloyd C Sims S Jones MC Rogers J Jiggins CD ffrench-Constant RH 《Nature》2011,477(7363):203-206
Supergenes are tight clusters of loci that facilitate the co-segregation of adaptive variation, providing integrated control of complex adaptive phenotypes. Polymorphic supergenes, in which specific combinations of traits are maintained within a single population, were first described for 'pin' and 'thrum' floral types in Primula and Fagopyrum, but classic examples are also found in insect mimicry and snail morphology. Understanding the evolutionary mechanisms that generate these co-adapted gene sets, as well as the mode of limiting the production of unfit recombinant forms, remains a substantial challenge. Here we show that individual wing-pattern morphs in the polymorphic mimetic butterfly Heliconius numata are associated with different genomic rearrangements at the supergene locus P. These rearrangements tighten the genetic linkage between at least two colour-pattern loci that are known to recombine in closely related species, with complete suppression of recombination being observed in experimental crosses across a 400-kilobase interval containing at least 18 genes. In natural populations, notable patterns of linkage disequilibrium (LD) are observed across the entire P region. The resulting divergent haplotype clades and inversion breakpoints are found in complete association with wing-pattern morphs. Our results indicate that allelic combinations at known wing-patterning loci have become locked together in a polymorphic rearrangement at the P locus, forming a supergene that acts as a simple switch between complex adaptive phenotypes found in sympatry. These findings highlight how genomic rearrangements can have a central role in the coexistence of adaptive phenotypes involving several genes acting in concert, by locally limiting recombination and gene flow. 相似文献
83.
A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva 总被引:5,自引:0,他引:5
Shore EM Xu M Feldman GJ Fenstermacher DA Cho TJ Choi IH Connor JM Delai P Glaser DL LeMerrer M Morhart R Rogers JG Smith R Triffitt JT Urtizberea JA Zasloff M Brown MA Kaplan FS 《Nature genetics》2006,38(5):525-527
Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder of skeletal malformations and progressive extraskeletal ossification. We mapped FOP to chromosome 2q23-24 by linkage analysis and identified an identical heterozygous mutation (617G --> A; R206H) in the glycine-serine (GS) activation domain of ACVR1, a BMP type I receptor, in all affected individuals examined. Protein modeling predicts destabilization of the GS domain, consistent with constitutive activation of ACVR1 as the underlying cause of the ectopic chondrogenesis, osteogenesis and joint fusions seen in FOP. 相似文献
84.
85.
Single amino acid substitutions in influenza haemagglutinin change receptor binding specificity 总被引:63,自引:0,他引:63
The haemagglutinin (HA) glycoproteins of influenza virus membranes are responsible for binding viruses to cells by interacting with membrane receptor molecules which contain sialic acid (for review see ref. 1). This interaction is known to vary in detailed specificity for different influenza viruses (see, for example, refs 2-4) and we have attempted to identify the sialic acid binding site of the haemagglutinin by comparing the amino acid sequences of haemagglutinins with different binding specificities. We present here evidence that haemagglutinins which differ in recognizing either NeuAc alpha 2 leads to 3Gal- or NeuAc alpha 2 leads to 6Gal- linkages in glycoproteins also differ at amino acid 226 of HA1. This residue is located in a pocket on the distal tip of the molecule, an area previously proposed from considerations of the three-dimensional structure of the haemagglutinin to be involved in receptor binding. 相似文献
86.
87.
A. J. Barnicoat W. G. van't Hoff P. J. Morrison H. J. Rogers 《Cellular and molecular life sciences : CMLS》1981,37(12):1290-1291
Summary The inferior in vivo efficacy of salicyl hydroxamic acid against trypanosomiasis may be explained by its short half-life, high degree of protein binding and low tissue levels. 相似文献
88.
Zusammenfassung Eine enzymatische, spektrophotometrische Bestimmungsmethode für Dihydroorotsäure im Urin und Serum wird beschrieben. 相似文献
89.
Summary The incorporation of3H-thymidine by Concanavalin A-stimulated human peripheral blood lymphocytes in vitro is inhibited by the presence of folate or folinate in the culture medium in a concentration-dependent manner. 相似文献
90.
E. S. Higgins W. H. Friend K. S. Rogers 《Cellular and molecular life sciences : CMLS》1978,34(5):578-579
Summary Induction of hepatic steatosis and suppression of hepatic ATP levels, protein synthesis and gluconeogenesis subsequent to administration of ethionine may be consequences of interference by this compound with mitochondrial phosphorylation of ADP. The mitochondrial dysfunction is not a direct action of ethionine on the organelle. 相似文献