全文获取类型
收费全文 | 85篇 |
免费 | 0篇 |
专业分类
理论与方法论 | 3篇 |
现状及发展 | 7篇 |
研究方法 | 29篇 |
综合类 | 44篇 |
自然研究 | 2篇 |
出版年
2021年 | 1篇 |
2013年 | 1篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 2篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1973年 | 2篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有85条查询结果,搜索用时 705 毫秒
41.
Allopatric speciation results from geographic isolation between populations. In the absence of gene flow, reproductive isolation arises gradually and incidentally as a result of mutation, genetic drift and the indirect effects of natural selection driving local adaptation. In contrast, speciation by reinforcement is driven directly by natural selection against maladaptive hybridization. This gives individuals that choose the traits of their own lineage greater fitness, potentially leading to rapid speciation between the lineages. Reinforcing natural selection on a population of one of the lineages in a mosaic contact zone could also result in divergence of the population from the allopatric range of its own lineage outside the zone. Here we test this with molecular data, experimental crosses, field measurements and mate choice experiments in a mosaic contact zone between two lineages of a rainforest frog. We show that reinforcing natural selection has resulted in significant premating isolation of a population in the contact zone not only from the other lineage but also, incidentally, from the closely related main range of its own lineage. Thus we show the potential for reinforcement to drive rapid allopatric speciation. 相似文献
42.
Identification of a ferrireductase required for efficient transferrin-dependent iron uptake in erythroid cells 总被引:10,自引:0,他引:10
Ohgami RS Campagna DR Greer EL Antiochos B McDonald A Chen J Sharp JJ Fujiwara Y Barker JE Fleming MD 《Nature genetics》2005,37(11):1264-1269
The reduction of iron is an essential step in the transferrin (Tf) cycle, which is the dominant pathway for iron uptake by red blood cell precursors. A deficiency in iron acquisition by red blood cells leads to hypochromic, microcytic anemia. Using a positional cloning strategy, we identified a gene, six-transmembrane epithelial antigen of the prostate 3 (Steap3), responsible for the iron deficiency anemia in the mouse mutant nm1054. Steap3 is expressed highly in hematopoietic tissues, colocalizes with the Tf cycle endosome and facilitates Tf-bound iron uptake. Steap3 shares homology with F(420)H(2):NADP(+) oxidoreductases found in archaea and bacteria, as well as with the yeast FRE family of metalloreductases. Overexpression of Steap3 stimulates the reduction of iron, and mice lacking Steap3 are deficient in erythroid ferrireductase activity. Taken together, these findings indicate that Steap3 is an endosomal ferrireductase required for efficient Tf-dependent iron uptake in erythroid cells. 相似文献
43.
44.
45.
Friesen TL Stukenbrock EH Liu Z Meinhardt S Ling H Faris JD Rasmussen JB Solomon PS McDonald BA Oliver RP 《Nature genetics》2006,38(8):953-956
New diseases of humans, animals and plants emerge regularly. Enhanced virulence on a new host can be facilitated by the acquisition of novel virulence factors. Interspecific gene transfer is known to be a source of such virulence factors in bacterial pathogens (often manifested as pathogenicity islands in the recipient organism) and it has been speculated that interspecific transfer of virulence factors may occur in fungal pathogens. Until now, no direct support has been available for this hypothesis. Here we present evidence that a gene encoding a critical virulence factor was transferred from one species of fungal pathogen to another. This gene transfer probably occurred just before 1941, creating a pathogen population with significantly enhanced virulence and leading to the emergence of a new damaging disease of wheat. 相似文献
46.
Jaeger E Webb E Howarth K Carvajal-Carmona L Rowan A Broderick P Walther A Spain S Pittman A Kemp Z Sullivan K Heinimann K Lubbe S Domingo E Barclay E Martin L Gorman M Chandler I Vijayakrishnan J Wood W Papaemmanuil E Penegar S Qureshi M;CORGI Consortium Farrington S Tenesa A Cazier JB Kerr D Gray R Peto J Dunlop M Campbell H Thomas H Houlston R Tomlinson I 《Nature genetics》2008,40(1):26-28
We mapped a high-penetrance gene (CRAC1; also known as HMPS) associated with colorectal cancer (CRC) in the Ashkenazi population to a 0.6-Mb region on chromosome 15 containing SCG5 (also known as SGNE1), GREM1 and FMN1. We hypothesized that the CRAC1 locus harbored low-penetrance variants that increased CRC risk in the general population. In a large series of colorectal cancer cases and controls, SNPs near GREM1 and SCG5 were strongly associated with increased CRC risk (for rs4779584, P = 4.44 x 10(-14)). 相似文献
47.
Yu TW Mochida GH Tischfield DJ Sgaier SK Flores-Sarnat L Sergi CM Topçu M McDonald MT Barry BJ Felie JM Sunu C Dobyns WB Folkerth RD Barkovich AJ Walsh CA 《Nature genetics》2010,42(11):1015-1020
Genes associated with human microcephaly, a condition characterized by a small brain, include critical regulators of proliferation, cell fate and DNA repair. We describe a syndrome of congenital microcephaly and diverse defects in cerebral cortical architecture. Genome-wide linkage analysis in two families identified a 7.5-Mb locus on chromosome 19q13.12 containing 148 genes. Targeted high throughput sequence analysis of linked genes in each family yielded > 4,000 DNA variants and implicated a single gene, WDR62, as harboring potentially deleterious changes. We subsequently identified additional WDR62 mutations in four other families. Magnetic resonance imaging and postmortem brain analysis supports important roles for WDR62 in the proliferation and migration of neuronal precursors. WDR62 is a WD40 repeat-containing protein expressed in neuronal precursors as well as in postmitotic neurons in the developing brain and localizes to the spindle poles of dividing cells. The diverse phenotypes of WDR62 suggest it has central roles in many aspects of cerebral cortical development. 相似文献
48.
McDonald D Vogelstein B King MC Hong WK Augustin H Hanahan D Lippman M 《Nature》2006,440(7087):978-979
49.
Gregory SG Barlow KF McLay KE Kaul R Swarbreck D Dunham A Scott CE Howe KL Woodfine K Spencer CC Jones MC Gillson C Searle S Zhou Y Kokocinski F McDonald L Evans R Phillips K Atkinson A Cooper R Jones C Hall RE Andrews TD Lloyd C Ainscough R Almeida JP Ambrose KD Anderson F Andrew RW Ashwell RI Aubin K Babbage AK Bagguley CL Bailey J Beasley H Bethel G Bird CP Bray-Allen S Brown JY Brown AJ Buckley D Burton J Bye J Carder C Chapman JC Clark SY Clarke G Clee C Cobley V Collier RE Corby N 《Nature》2006,441(7091):315-321
The reference sequence for each human chromosome provides the framework for understanding genome function, variation and evolution. Here we report the finished sequence and biological annotation of human chromosome 1. Chromosome 1 is gene-dense, with 3,141 genes and 991 pseudogenes, and many coding sequences overlap. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Fine-scale recombination occurs in hotspots of varying intensity along the sequence, and is enriched near genes. These and other studies of human biology and disease encoded within chromosome 1 are made possible with the highly accurate annotated sequence, as part of the completed set of chromosome sequences that comprise the reference human genome. 相似文献
50.
Jerry N. McDonald 《西北部美国博物学家》2011,45(3)
A partial cranium belonging to the extinct woodland musk - ox, Symbos cavifrons, is reported from the headwaters of Oak Creek, Delta County, Colorado. This is the first cranium of the genus Symbos to be described from the Colorado Plateau, and it helps to define the southwest boundary of the known range of the genus. 相似文献