全文获取类型
收费全文 | 186篇 |
免费 | 19篇 |
出版年
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 20篇 |
1998年 | 9篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有205条查询结果,搜索用时 879 毫秒
41.
42.
43.
44.
Peter R. Shewry 《Plant Growth Regulation》2000,30(3):275-276
45.
46.
47.
Etiolated barley seedlings lose the ability to produce chlorophyll and soluble protein on exposure to light with increasing age. Similarly, the production of δ-aminolaevulinic acid-dehydratase and succinyl-CoA synthetase is decreased in older etiolated leaves exposed to light. The rate of protochlorophyllide652 regeneration decreased well before the rates of exogenous δ-aminolaevulinic acid conversion to protochlorophyllide632 was affected by ageing. Application of kinetin retarded these ageing symptoms in the etiolated leaves. 相似文献
48.
G. A. Toole C. Barron G. Le Gall I. J. Colquhoun P. R. Shewry E. N. C. Mills 《Planta》2009,229(3):667-680
Previous studies using spectroscopic imaging have allowed the spatial distribution of structural components in wheat endosperm
cell walls to be determined. FT-IR microspectroscopy showed differing changes in arabinoxylan (AX) structure, during grain
development under cool/wet and hot/dry growing conditions, for differing cultivars (Toole et al. in Planta 225:1393–1403,
2007). These studies have been extended using Raman microspectroscopy, providing more details of the impact of environment
on the polysaccharide and phenolic components of the cell walls. NMR studies provide complementary information on the types
and levels of AX branching both early in development and at maturity. Raman microspectroscopy has allowed the arabinose:xylose
(A/X) ratio in the cell wall AX to be determined, and the addition of ferulic acid and related phenolic acids to be followed.
The changes in the A/X ratio during grain development were affected by the environmental conditions, with the A/X ratio generally
being slightly lower for samples grown under cool/wet conditions than for those from hot/dry conditions. The degree of esterification
of the endosperm cell walls with ferulic acid was also affected by the environment, being lower under hot/dry conditions.
The results support earlier suggestions that AX is either delivered to the cell wall in a highly substituted form and is remodelled
through the action of arabinoxylan arabinofuranohydrolases or arabinofuranosidases, or that low level substituted AX are incorporated
into the wall late in cell wall development, reducing the average degree of substitution, and that the rate of this remodelling
is influenced by the environment. 1H NMR provided a unique insight into the chemical structure of intact wheat endosperm cell walls, providing qualitative information
on the proportions of mono- and disubstituted AX and the levels of branching of adjacent units. The A/X ratio did not change
greatly with either the development stage or the growth conditions, but the ratio of mono- to disubstituted Xylp residues increased markedly (by about fourfold) in the more mature samples, confirming the changes in branching levels determined
using FT-IR. To the best of our knowledge, this is the first time that intact endosperm cell walls have been studied by 1H NMR. 相似文献
49.
G. A. Toole G. Le Gall I. J. Colquhoun C. Nemeth L. Saulnier A. Lovegrove T. Pellny M. D. Wilkinson J. Freeman R. A. C. Mitchell E. N. C. Mills P. R. Shewry 《Planta》2010,232(3):677-689
A combination of enzyme mapping, FT-IR microscopy and NMR spectroscopy was used to study temporal and spatial aspects of endosperm cell wall synthesis and deposition in developing grain of bread wheat cv. Hereward. This confirmed previous reports that changes in the proportions of the two major groups of cell wall polysaccharides occur, with β-glucan accumulating earlier in development than arabinoxylan. Changes in the structure of the arabinoxylan occurred, with decreased proportions of disubstituted xylose residues and increased proportions of monosubstituted xylose residues. These are likely to result, at least in part, from arabinoxylan restructuring catalysed by enzymes such as arabinoxylan arabinofurano hydrolase and lead to changes in cell wall mechanical properties which may be required to withstand stresses during grain maturation and desiccation. 相似文献
50.
Tatham AS Shewry PR 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2002,357(1418):229-234
Elastic proteins are characterized by being able to undergo significant deformation, without rupture, before returning to their original state when the stress is removed. The sequences of elastic proteins contain elastomeric domains, which comprise repeated sequences, which in many cases appear to form beta-turns. In addition, the majority also contain domains that form intermolecular cross-links, which may be covalent or non-covalent. The mechanism of elasticity varies between the different proteins and appears to be related to the biological role of the protein. 相似文献