Search Results
Schützendübel, A., Nikolova, I. P., Rudolf, C., Polle, A. (2002) Cadmium and H 2 O 2 -induced oxidative stress in Populus × canescens roots. Plant Physiol. Biochem. 40 , 577–584. Polle A
Schützendübel, A., Nikolova, I. P., Rudolf, C., Polle, A. (2002) Cadmium and H 2 O 2 -induced oxidative stress in Populus × canescens roots. Plant Physiol. Biochem. 40 , 577–584. Polle A
366 Bouazizi, H., Jouili, H., Geitmann, A., El Ferjani, E. (2008) Effect of copper excess on H2O2 accumulation and peroxidase activities in bean roots. Acta Biol. Hung. 59 , 233
195 200 Wahid, A., Perveen, M., Gelani, S., Basra, S.M.A. 2007. Pretreatment of seed with H 2 O 2 improves salt tolerance of wheat seedlings by alleviation of oxidative damage
687 706 Thordal-Christensen, H., Zhang, Z., Wei, Y., Collinge, D.B. 1997. Subcellular localization of H 2 O 2 in plants. H 2 O 2 accumulation in papillae and
Abstract
A new method for the continuous determination of H2O2 is described based on the catalytic decomposition of H2O2 by LaCoO3. Oxygen liberated is measured by a gas meauuring burette. 
-irradiated catalyst enhances the catalytic activity and decreases the time required for complete decomposition. The procedure is suitable for microdetermination of H2O2 in various food products.
The aim of the present study was to evaluate the potential of Turkish propolis extracts if they prevent or protect foreskin fibroblast cells against hydrogen peroxide (H2O2)-induced oxidative DNA damage. Hydrogen peroxide (40 μM) was used as an inducer of oxidative DNA damage. The damage of DNA was evaluated by using the alkaline single cell gel electrophoresis (comet) assay. Turkish propolis extracts at concentrations of 25, 50, 75 and 100 μg/ml were prepared by ethanol. Anti-genotoxicity was assessed before, simultaneously, and after treatment of propolis extract (50 μg/ml) with H2O2. The results showed a significant decrease in H2O2-induced DNA damage in cultures treated with propolis extract. The antioxidant activity of phenolic components found in propolis may contribute to reduce the DNA damage induced by H2O2. Our findings confirmed the chemopreventive activity of propolis and showed that this effect may occur under different mechanisms.
Abstract
The non-isothermal decomposition kinetics of 4Na2SO4·2H2O2·NaCl have been investigated by simultaneous TG-DSC in nitrogen atmosphere and in air. The decomposition processes undergo a single step reaction. The multivariate nonlinear regression technique is used to distinguish kinetic model of 4Na2SO4·2H2O2·NaCl. Results indicate that the reaction type Cn can well describe the decomposition process, the decomposition mechanism is n-dimensional autocatalysis. The kinetic parameters, n, A and E are obtained via multivariate nonlinear regression. The n th-order with autocatalysis model is used to simulate the thermal decomposition of 4Na2SO4·2H2O2·NaCl under isothermal conditions at various temperatures. The flow rate of gas has little effect on the decomposition of 4Na2SO4·2H2O2·NaCl.
Abstract
A feasibility and basic study to find a possibility to develop such a process for recovering U alone from spent fuel by using the methods of an oxidative leaching and a precipitation of U in high alkaline carbonate media was newly suggested with the characteristics of a highly enhanced proliferation-resistance and more environmental friendliness. This study has focused on the examination of an oxidative leaching of uranium from SIMFUEL powders contained 16 elements (U, Ce, Gd, La, Nd, Pr, Sm, Eu, Y, Mo, Pd, Ru, Zr, Ba, Sr, and Te) using a Na2CO3 solution with hydrogen peroxide. U3O8 was dissolved more rapidly than UO2 in a carbonate solution. However, in the presence of H2O2, we can find out that the leaching rates of the reduced SIMFUEL powder are faster than the oxidized SIMFUEL powder. In carbonate solutions with hydrogen peroxide, uranium oxides were dissolved in the form of uranyl peroxo-carbonato complexes. UO2(O2) x (CO3) y 2−2x−2y , where x/y has 1/2, 2/1.
Abstract
This study was carried out to investigate the characteristics of an oxidative-dissolution of fission products (FP) when uranium (U) is dissolved in a Na2CO3–H2O2 carbonate solution. Simulated FP-oxides which contained 12 components were added to the solution to examine their dissolution behaviors. It was found that H2O2 was an effective oxidant to minimize the dissolution of FP. For the 0.5 M Na2CO3–0.5 M H2O2 solution, such elements as Re, Te, Cs, and MoO2 were dissolved with yields of 98 ± 2%, 98 ± 2%, 93 ± 2%, and 26 ± 3%, respectively, for 2 h. Among these components, Re, Te, and Cs were completely dissolved within 10–20 min without regard to the concentrations of Na2CO3, and H2O2 due to their high solubility in the carbonate solution with and without H2O2. However, MoO2 was very slowly dissolved and its yield was 29 ± 3% for 4 h. The pH of the dissolved solution revealed the greatest influence on the dissolution yields of the FP, exhibiting the most effective pH condition in the range of 10–12 in order to create a considerable suppression of the co-dissolution of FP during the oxidative-dissolution of U.
