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61.
The interaction of phosphine with purified cytochrome c and cytochrome oxidase was studied by absorption and circular dichroic spectrometry. Treatment of cytochrome oxidase with phosphine yielded absorption spectra in both the visible and Soret region that were similar to that produced by dithionite. Striking changes in the circular dichroic spectra were also recorded, sugesting that a valence change of the heme iron was accompanied by a conformation change of the prosthetic group.Phosphine treatment of cytochrome c also yielded spectra similar to those produced by reduction with dithionite suggesting a valence change of the heme iron. However, both the time necessary for complete reduction and the concentration of phosphine necessary for this effect suggest that, in comparison with cytochrome oxidase, cytochrome c was relatively insensitive. Reduction of cytochrome oxidase by phosphine had only a very minor effect on the intrinsic dichroic spectrum suggesting little effect on the polypeptide chains.The persistence of a component after reduction by phosphine and the subsequent reduction of this component by dithionite suggests that phosphine primarily reduced only one comonent of the cytochrome aa3 complex. The failure of EDTA and fluoride, which are known ligands of cytochrome a3 to affect the reduction of cytochrome aa3 by phosphine, as well as the occurrence of a 436-nm isosbestic point of the ferric-ferrous absorption spectra suggests that phosphine reduced primarily cytochrome a. However, it is argued that a slow reduction of cytochrome a3 cannot be ruled out. 相似文献
62.
草地是发展畜牧业的重要基础,退牧还草工程是恢复、更新天然草地和保护生态环境的重要手段。本文就新疆实施退牧还草工程中所出现的一些问题进行了探讨。 相似文献
63.
《Livestock Production Science》2005,95(3):255-263
The aim of the experiment was to investigate the effects of cage floor and cage density on stress parameters of laying hens. A total of 162 brown laying hens (Hyline Brown), aged 34 weeks, were used in the experiment. Compact-type battery cages, with three floors, were used. Hens were allocated as one, three or five hens in each of 18 cages to obtain three different cage density groups of 1968, 656 and 393.8 cm2 floor area per hen, respectively. The same number of cages with different cage density were allocated to three different battery floors (first floor=top, second=middle, third=bottom) systematically. Values for body weight, mortality rate, egg weight, egg production, egg quality characteristics, egg yolk cholesterol content, the levels of blood plasma corticosterone, serum glucose, total cholesterol and triglycerides, the ratio of heterophils to lymphocytes (H-L ratio), antibody titers, claw length score, foot health score, plumage score and throat skin injuries were taken as indicators of stress. The values for egg weight (P<0.01) at the first floor were greater than the other floor levels. The group with five hens per cage had significantly lower mean estimates (P<0.01) than other groups with respects to body weight (P<0.001), egg production (P<0.001), egg weight (P<0.001) and plumage score (P<0.01), while significantly higher mean estimates for egg albumen index (P<0.01), Haugh unit (P<0.01), serum glucose (P<0.001), and H-L ratio (P<0.001). Serum cholesterol was higher in cages with one hen than that with five hens, whereas plasma corticosterone was lower. Antibody titers in cages with one hen was similar to that with three or five hens; however, those with three hens had higher titers than those with five hens. Values for egg breaking strength, yolk index, egg cholesterol content, and foot health score were not affected by cage density or floor. The results suggest that the allocation of three hens per cage had no measurable effect on health and welfare. 相似文献
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66.
邱德玉 《四川畜牧兽医学院学报》2005,3(4):5-8
文化底蕴越是丰厚的旅游资源,开发价值就越高。正是众多文人贤士游剡访古,使浙东剡溪的历史、文化与自然山水完美地结合在一起,形成了绚丽多彩的剡溪山水文化。文化被认为是旅游业的灵魂,是一种潜在的旅游产品。要提高山水旅游产品的文化品位,必须将山水文化的潜在价值转化为旅游产品。本文对剡溪山水文化旅游资源的开发提出了以下设想:再现“唐诗之路”山水旅游美景,并着重于按唐诗及有关文献、传说等增添新景点,沿江、沿山、于水中进行山水、文化全面开发,形成立体式、全景式的剡中山水文化游道;可开发出文化生态、修学、科考、宗教、节庆等剡溪山水文化旅游产品。 相似文献
67.
双孢蘑菇性亲和性相关分子标记的初步筛选 总被引:4,自引:0,他引:4
以传统的形态,生理生化分析和最新的DCS-PDMA性亲和性测定方法为基础, 结合群体分离分析和RAPD技术来源于同一双孢蘑菇异核体菌株的12个不育同核原生质体个体进行分析,筛选与性亲和性相关的分子标记。研究结果表明,供试的12个不育同核原生质体个体被分成两大类性亲和性类型,其中一类(A^ )包括不育同核原生质体个体B、C、D、E、F、G、H、I、J、L,另一类(A^-)则仅仅包括不育同核原生质体个体K和M,同时筛选到一个与性亲和性相关的分子标记OPA16 1500。从而为间地利用双孢蘑菇本身特有的交配型作标记来指导杂交育种工作和进一步将性亲和性基因定位分离克隆奠定了坚实的基础。 相似文献
68.
许多固氮树种速生丰产,萌生能力强,叶片,木屑含氮率较高,可为食用菌栽培提供理想原料,而且固氮树种在绿花荒山,保持水土,提高地力方面作用显著,以固氮树种发展短轮伐期食用菌专用林,具有较高的经济效益和生态效益,本文介绍了银合欢,黑荆,大叶相思,银荆,桤木,南洋楹和马占相思等在食用菌栽培上的应用概况,各地可因地制宜栽培合适的固氮树种作为食用菌专用林。 相似文献
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