全文获取类型
收费全文 | 81篇 |
免费 | 14篇 |
出版年
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有95条查询结果,搜索用时 203 毫秒
71.
RICCARDO BOMMARCO MIKAEL LÖNN ULRIKA DANZER KARL‐JOHAN PÅLSSON PETER TORSTENSSON 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(4):797-807
Rapid evolutionary change is increasingly being recognized as commonplace, but the evolutionary consequences for species and ecosystems under human‐induced selection regimes have not been explored in detail, although many species occur in such environments. In a common garden experiment and with amplified fragment length polymorphism markers, we examined whether genetic differentiation has taken place between spatially intermixed populations of creeping thistles Cirsium arvense (Asteraceae) collected from a natural habitat (maritime shores), a semi‐natural habitat (road verges) and arable fields under two management regimes: conventional and organic farming. Populations of C. arvense have altered genetically and locally adapted their growth patterns with changed land use. Although plants from different habitats showed similar total biomass production, shoot and root production was higher for maritime populations, suggesting selection for increased competitive ability. Competitive ability then declined in the order semi‐natural, conventional farms and organic farms. Thistles in arable fields may be more selected for tolerance against disturbances from herbicides and mechanical weed control. In addition, early shoot sprouting and genetic analysis showed differentiation between plants originating from conventional farms and farms that were converted to organic 9–30 years ago, suggesting some adaptation to altered crop cultivation practices. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 797–807. 相似文献
72.
73.
74.
75.
Significant enhancement of fluorescence on hybridization of a molecular beacon to a target DNA in the presence of a site-specific DNA nickase 总被引:1,自引:0,他引:1
Zheleznaya LA Kopein DS Rogulin EA Gubanov SI Matvienko NI 《Analytical biochemistry》2006,348(1):123-126
We have developed a simple isothermal (55 degrees C) reaction that permits detection of DNA targets using only two components: a molecular beacon and a site-specific DNA nickase without deoxyribonucleotide triphosphates and primers. The loop sequence of the molecular beacon should contain a DNA nickase recognition site. The nickase-molecular beacon (NMB) combination permits a 100-fold increase in fluorescent signal. The applications of the NMB assay for enhancement of fluorescent signal in some isothermal methods are discussed. 相似文献
76.
Changes of the pulmonary artery branches in rats at the state of relative physiological rest undergo two stages during the process of individual adaptation for 60 days. The first is characterized with generalized decrease of the lumen and with thickening of the vascular wall as a result of reflectory spasm and edematous swelling of the arteries, the second--with a relative dilatation of the lumen and with decreasing thickness of the vascular wall, as a result of decreasing reflectory spasm and edematous phenomena. The physical load increases the organism's elevated oxygen consumption under conditions of high-altitude, which is increased by itself; this intensifies the function of the pulmonary blood bed. In combination with the edematous phenomena, the wall of the pulmonary artery becomes sharply thickened in the first stage. In the second stage the tissue mechanisms are switched on for satisfaction of oxygen consumption. Therefore, the load on the right part of the heart and on the pulmonary vessels decreases edematous phenomena, the thickness of the wall in the pulmonary artery branches decline, in comparison with the data of the first stage. The thickness of the wall in the first stage is combined with a manifested constriction of the lumen, and the relative thinning of the vascular wall--with dilatation. 相似文献
77.
V M Kramarov A I Fomenkov N I Matvienko R Kh Ubieta V V Smolianinov 《Bioorganicheskaia khimiia》1987,13(6):773-776
A sequence-specific endonuclease CauB3I has been isolated from cell extracts of Chloroflexus aurantiacus and partially purified by chromatography on heparin-sepharose; the yield was 3000 units per 1 g of cells. The final preparation is free of non-specific nucleases. It is shown that endonuclease CauB3I recognizes 5' T decreases CCGGA 3' sequence in double-stranded DNA and cleaves it as shown by an arrow. Methylation of adenine in the recognition sequence makes it resistant to CauB3I. 相似文献
78.
79.
Development,polymorphism, and cross-taxon utility of EST–SSR markers from safflower (<Emphasis Type="Italic">Carthamus tinctorius</Emphasis> L.) 总被引:1,自引:0,他引:1
Mark A. Chapman John Hvala Jason Strever Marta Matvienko Alexander Kozik Richard W. Michelmore Shunxue Tang Steven J. Knapp John M. Burke 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,120(1):85-91
The breeding of japonica varieties with erect-pose panicle (EP) has recently progressed in the northern part of China, because these varieties exhibit
a far higher grain yield than the varieties with normal-pose panicle (NP). A genetic analysis using the F2 population from the cross between Liaojing5, the first japonica EP variety in China, and the Japanese japonica NP variety Toyonishiki revealed that EP is governed by a single dominant gene EP. Based on previous studies, map-based cloning of EP locus was conducted using Liaojing5, Toyonishiki, their F2 population, and a pair of near-isogenic lines for EP locus (ZF14 and WF14) derived from the cross between the two varieties; consequently, the STS marker H90 was found to completely
cosegregate with panicle pose. The H90 is located in the coding sequence AK101247 in the database, and the AK101247 of Liaojing5
has a 12 bp sequence in exon 5 replaced with a 637 bp sequence of its wild type allele. It was therefore considered that the
AK101247 encodes the protein of the wild type allele at EP locus, and that the sequence substitution in exon 5 of Liaojing5 is crucial for expression of the EP phenotype. The effects
of EP gene on agronomic traits were investigated using two pairs of near-isogenic lines (ZF6 vs. WF6 and ZF14 vs. WF14) derived
from the cross between the two varieties. Experimental results showed that EP gene markedly enhanced grain yield, chiefly by increasing number of secondary branches and number of grains on the secondary
branch. EP gene also produced a remarkable increase in grain density. 相似文献
80.
The mechanism of cross-reactivation after UV-irradiation was examined using different deletion mutants as recipients. A model of the rescue mechanism of partly diploid area was suggested. The method of cross-reactivation in demonstrated to permit an easy determination of the orientation of duplicated genes. 相似文献