5 resultados para Oxygen Uptake
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
The reaction rates of MTPP with oxygen in air are Inas than that with pure oxygen, the ratio is roughly the same as to the partial presence of imygen in air, The influences of S-ligand etbanethiol and O- litand Vc on the above Systems have also been investigated, the former makes the MP hands having more changes and the reaction rate constants becoming greater, the latter has less influence.
Resumo:
在光系统I(PSI)内部结合有大量的水分子,而这些水分子的生理功能还不清楚。在本工作中,我们通过外加具有渗透活性和吸水强的多羟基化合物甘油和蔗糖来改变PSI环境中水的含量,研究水的改变对PSI结构与功能的影响。主要结果如下: 1.甘油和蔗糖对PSI的电子传递产生影响,影响程度和大小与它们的浓度有关。一般地,低浓度的甘油和蔗糖可促进PSI的电子传递,而在高浓度时,这种促进作用有所减弱。但过高浓度的甘油(>60%, v/v)会抑制PSI的电子传递活性。 2.与对PSI电子传递的影响趋势相类似,在低浓度的甘油和蔗糖存在下,PSI的光化学反应活性(PSI反应中心色素P700的光氧化还原能力)大为增加,而较高浓度的甘油和蔗糖对P700的氧化还原能力有所抑制。 3.甘油和蔗糖也会改变PSI中的主体色素(bulk chlorophyll)和长波色素或红色素(red chlorophyll)之间的能量分布。它们的作用导致激发能分配失衡,使更多的激发能分配到红色素。 4.甘油和蔗糖的作用还会影响PSI的蛋白质构象。甘油使PSI蛋白质内部的色氨酸残基(Trpapolar)处于更加疏水的微环境,而蔗糖却使极性环境中的色氨酸残基(Trppolar)周围微环境的极性继续增大。它们均会使色氨酸残基邻近的具有淬灭活性的蛋白质的位置和/或方向有所变化。同时,甘油和蔗糖的作用也会导致PSI的疏水性增加。
Resumo:
Textile wastewater is commonly treated with activated sludge process technology. However, its treatment performance has not been demonstrated to be very effective. In this study, the effects of micronutrient thiamine on removal efficiencies of dissolved organic carbon (DOC) and chemical oxygen demand (COD) of textile wastewater in a batch test, together with its effect on the oxygen uptake rate (OUR) of activated sludge, were evaluated. Significant improvements were observed in the removal rates of DOC, COD and OUR with 121%, 156% and 121% of those of the control, respectively, when 0.5-2.0 mg/L thiamine was added to the wastewater treatment system. Thiamine could be probably used to improve the treatment performance of textile wastewater.
Resumo:
Transgenic animals with improved qualities have the potential to upset the ecological balance of a natural environment. We investigated metabolic rates of 'all-fish' growth hormone (GH) transgenic common carp under routine conditions and during starvation periods to determine whether energy stores in transgenic fish would deplete faster than controls during natural periods of starvation. Before the oxygen uptake was measured, the mean daily feed intake of transgenic carp was 2.12 times greater than control fish during 4 days of feeding. The average oxygen uptake of GH transgenic fish was 1.32 times greater than control fish within 96 h of starvation, but was not significantly different from controls between 96 and 144 h of starvation. At the same time, GH transgenic fish did not deplete energy reserves at a faster rate than did the controls, as the carcass energy contents of the two groups following a 60-d starvation period were not significantly different. Consequently, we suggest that increased routine oxygen uptake in GH transgenic common carp over that of control fish may be mainly due to the effects of feeding, and not to an increase in basal metabolism. GH transgenic fish are similar to controls in the regulation of metabolism to normally distribute energy reserves during starvation. (c) 2008 Published by Elsevier B.V.
Resumo:
The thermal oxidation behaviour of polypropylene containing tetramethylpiperidine compounds and corresponding pentamethylpiperidine compounds are compared using air oven aging, oxygen uptake and thermogravimetry. Carbonyl formation, the induction period of oxygen absorption and weight loss have been selected to characterize the degree of oxidation. The results show that the stabilizing effectiveness of pentamethylpiperidines is always higher than that of tetramethyl types. Radical-trapping mechanisms cannot explain this, because large amounts of nitroxyl radicals are formed by the tetramethylpiperidine compounds. The quenching of singlet oxygen appears to be involved in thermal oxidation of polypropylene containing pentamethylpiperidine compounds. Specific hydrogen bonding between pentamethylpiperidines and hydroperoxide may account for their better thermal stabilizing action than tetramethylpiperidines.