Antioxidant effects of reduced water produced by electrolysis of sodium chloride solutions

Antioxidant vitamins and enzymes such as superoxide dismutase, catalase and glutathione peroxidase are considered to function as scavengers against reactive oxygen species and to provide protection against reactive oxygen species, including free radicals. Although antioxidants such as L-ascorbic acid, d-catechin and quercetin dehydrate show superoxide dismutation activity, using reduced water produced in the cathode side by electrolysis as a solvent instead of 2 mM NaC1 solution of the same pH level as the reduced water increased the superoxide dismutation activity of these antioxidants. Moreover, neither the reduced water nor its electrolyte solution showed any superoxide dismutation activity by itself. On the other hand, the reduced water was able to decrease hydrogen peroxide levels. It has been found that the behaviour of H₂ in reduced water, which was activated by a platinum electrode, differed from that of H₂ introduced by bubbling of hydrogen gas. The former decreased H₂O₂, whereas the latter did not. These results suggest strongly that the increase in superoxide dismutation activity, with a proton donor such as L-ascorbic acid, is due to an increase in the dissociation activity of water while the scavenging activity for H₂O₂ is due to activated dissolved H₂ in the reduced water.     

Preparation of monodisperse Se colloid spheres and Se nanowires using Na2SeSO3 as precursor

Nearly monodisperse spherical amorphous Se colloids are prepared by the dismutation of Na₂SeSO₃ solution at room temperature; by altering the pH of the solution, amorphous Se colloid spheres with sizes of about 120 nm, 200 nm, 300 nm, and 1 μm can be obtained. Se@Ag₂Se core/shell spheres are successfully synthesized by using the obtained amorphous Se (a-Se) spheres as templates, indicating the potential applications of these Se nanomaterials in serving as soft templates for other selenides. Meanwhile, selenium nanowires are obtained through a “solid-solution-solid” growth process by dispersing the prepared Se spheres in ethanol. This simple and environmentally benign approach may offer more opportunities in the synthesis and applications of nanocrystal materials. This article is published with open access at Springerlink.com     

Biohydrogenation of fumarate using Desulfovibrio desulfuricans: experimental results and kinetic rate modelling

The biological hydrogenation of organic compounds using sulphate-reducing bacteria was investigated. A high pressure stainless steel bioreactor and an atmospheric pressure reactor were constructed so that identical reactions at different pressures could be compared. The mesophillic sulphate-reducing bacteria Desulfovibrio desulfuricans (ATCC 7757) were used. Qualitative tests showed that Desulfovibrio desulfuricans was able to retain its viability at hydrogen pressures up to 35 atmospheres at a temperature of 37°C when exposed to fumarate. Evidence of fumarate dismutation was observed since half of the fumarate was converted to succinate. The effect of bacterial cell concentration was also studied under hydrogen gas. For a doubling of the bacterial cell (reactivated) concentration, the conversion of fumarate doubled from 40% to 80% in 12 h. A first-order reaction rate model was fit to the fumarate concentration data. The first-order reaction rate constant was found to be a linear function of the bacterial cell concentration. ©1997 SCI     

新戊二醇生产工艺研究进展

新戊二醇及其衍生物具有良好的耐水性、耐热性和耐光性,这些优良的特性使新戊二醇具有广泛的应用领域。新戊二醇工业上采用甲醛和异丁醛缩合合成,歧化法用液碱催化缩合,加氢法先用三乙胺催化,然后进行催化加氢。加氢法在产品质量、经济指标和环保要求方面均优于歧化法,因此,建议改进现有歧化法工艺装置,新建装置尽可能采用加氢法。     

Formation of carbon nanotubes from the carbon monoxide disproportionation reaction over Co/Al2O3 and Co/SiO2 catalysts

The ammonia method has been successfully used for preparing thermostable and well dispersed alumina‐supported catalysts with a surface average size of cobalt particle D _{s= 5.7} nm. The disproportionation reaction of CO over this Co/Al₂O₃ catalyst and a similar Co/SiO₂ catalyst leads to the formation of carbon nanotubes demonstrating the same morphology. The amount of nanotubes over Co/Al₂O₃, however, is much larger than that obtained over Co/SiO₂, because of a faster ageing in the latter solid. Similar support effects have already been reported for other catalytic reactions involving carbon oxides. This revised version was published online in July 2006 with corrections to the Cover Date.     

Application of polarisation curves to the study of the electrochemical process for producing cuprous oxide

Polarisation curves are useful for establishing the optimum experimental conditions for producing electrolytic cuprous oxide. They provide a reasonable means of determining the influence of each variable on cuprous oxide formation at an electrode surface. In this work, a sodium chloride solution was electrolysed, and sodium hydroxide and sodium nitrate (in several concentrations) were added in successive stages to determine the behaviour of the resultant systems. Finally, the effect of the presence of cuprous oxide on the cathodic behaviour of the electrode was studied. The working electrode was of copper and the experiments were conducted at different temperatures. The polarisation curves were obtained without agitating the liquid and with aerated and deaerated solutions. The passage of nitrogen during 30 min removed oxygen from the electrolyte.     

国内新戊二醇生产工艺评述

新戊二醇主要用于制造高档树脂和粉末涂料,工业上采用甲醛和异丁醛缩合合成。歧化法工艺用液碱催化缩合;加氢法工艺用三乙胺催化,然后进行催化加氢。建议选择原料资源丰富、用户相对集中的地区建设一两套大型加氢法生产装置,以及改进现有的歧化法工艺。