• 한국염색가공학회지
• /
• 제6권1호
• /
• pp.1-7
• /
• 1994

A low-temperature dyeing system for silk fabrics based on a redox system has been investigated. Some factors affecting dyeing of silk fabrics with levelling acid dyes in the absence and presence of certain redox system were investigated under different conditions. The variables studied were; type and concentration of redox system, dyeing conditions, i. e. temperature and time, dye concentration, material-to-liquor ration(LR) and colour fastness. The colour strength(K/S value) is outstandingly higher in the presence than in the absence of redox system. A comparison between the colour strength values of such dyeings abtained the three redox system would call for the following order ; Glyoxal/hydrogen peroxide>thiourea/hydrogen peroxide>glucose/hydrgen peroxide> nothing. In the presence of redox system, free radicals are supposed to be formed in both the fiber and the dye and the interaction between these free radicals bring about covalent fixation beside the usual electrostatic bonds, hydrogen bonds and Van der Waals forces.

• 한국식품영양과학회지
• /
• 제26권6호
• /
• pp.998-1005
• /
• 1997

Kimchi showed protective effect from oxidative damage generated by hydrogen peroxide and paraquat. To investigate the major components of kimchi which reduce the cytotoxicity against reactive oxygen species, keratinocyte(A431, epidermoid carcinoma, human) and fibroblast(CCD-986SK, normal control, human) were cultured under oxidative stress condition provoked by paraquat, a superoxide anion generator, and hydrogen peroxide in the absence or presence of kimchi ingredients. Most keratinocyte and fibroblast cells were killed by hydrogen peroxide and paraquat over 1mM concentration, but kimchi ingredients showed protective effects from oxidative damage generated by hydrogen peroxide and onion, among those, garlic showed the most remarkable preventive effect. Most of kimchi ingredients showed protective effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect from cell killing by high dose of hydrogen peroxide, but most ingredients were not effective against paraquat.

• 한국식품영양과학회지
• /
• 제26권6호
• /
• pp.1159-1163
• /
• 1997

We have studied the effect of 31 extracts and 10 components from some edible and medicinal plants on the formation of lipid peroxide in the liver homogenate of rat in vitro. The 70% acetone extracts of Allium tuberosum, Beta vulgaris var. cicla and Brassica juncea var. integrifolia, and methanol extract of Capsicum annuum decreased the formation of lipid peroxide by 33%, 58%, 62% and 56% at the concentration of 1mg/ml, respectively. And these four extracts inhibited the lipid peroxidation at the concentration of $10^{-1}$mg/ml by 17%, 46%, 49% and 45% respectively. Among the component tested, quercetin, quercitrin and isorhamnetin reduced the formation of lipid peroxide by 45%, 15% and 28% respectively at the concentration of $10^{-2}$mg/ml.

• 약학회지
• /
• 제56권6호
• /
• pp.390-394
• /
• 2012

A series of new pyridazinyl sulfoxides 3a~e and pyridazinyl sulfones 4a were synthesized for development of candidates to retain anticancer activity. The utility of sulfoxides and sulfones in both laboratory and industrial practice was quickly recognized, and these species have been extensively utilized, including as pharmaceutical intermediates and anticancer agents. Alkylthiopyridazines 2a~e were prepared from the 3,6-dichloropyridazine using allylthiolation with alkyl mercaptan. Sulfides could be oxidized to sulfoxides or sulfones using 1~3 equivalents of hydrogen peroxide as an oxidant. The oxidation of sulfoxides to sulfones was also accomplished with aqueous hydrogen peroxide. Formation of 3a~e and 4a was undertaken with stirring using 35% hydrogen peroxide at room temperature in acetic acid for 18~72 h. Synthetic compounds were identified using NMR spectrum.

• Nuclear Engineering and Technology
• /
• 제53권1호
• /
• pp.142-147
• /
• 2021

Hydrogen peroxide is a radiolysis product of water formed under gamma-irradiation; therefore, its reliable detection is crucial in the nuclear industry for spent fuel management and coolant chemistry. This study proposes an electrochemical sensor for hydrogen peroxide detection. Cysteamine (CYST), gold nanoparticles (GNPs), and horseradish peroxidase (HRP) were used in the modification of a gold electrode for fabricating Au/CYST/GNP/HRP sensor. Each modification step of the electrode was investigated through electrochemical and physical methods. The sensor exhibited strong sensitivity and stability for the detection and measurement of hydrogen peroxide with a linear range of 1-9 mM. In addition, the Michaelis-Menten kinetic equation was applied to predict the reaction curve, and a quantitative method to define the dynamic range is suggested. The sensor is highly sensitive to H₂O₂ and can be applied as an electrochemical H₂O₂-sensor in the nuclear industry.

• 대한화학회지
• /
• 제67권6호
• /
• pp.415-419
• /
• 2023

In this study, we report the one-pot synthesis of reduced graphene oxide (rGO) containing platinum nanoparticles with catalytic activity to break down hydrogen peroxide as a peroxidase-mimicking catalyst. A single reducing agent was used to reduce graphene oxide and a platinum precursor at a moderately low temperature of 70℃. The rGO was homogeneously decorated with platinum nanoparticles. The catalytic activity of Pt-rGO was investigated for the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB), a peroxidase substrate, in the presence of hydrogen peroxide. The Pt-rGO coupled with glucose oxidase was also able to detect glucose at millimolar concentrations (up to 1 mM). Our results show that the Pt-rGO composite is a promising catalyst for the detection of hydrogen peroxide. This method was also applied for the detection of glucose.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권1호
• /
• pp.90-95
• /
• 2005

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets.

• 펄프종이기술
• /
• 제47권4호
• /
• pp.81-87
• /
• 2015

Soda-AQ pulp made from sugarcane bagasse (SCB) were bleached in element chlorine free (ECF) sequence. To reduce chlorine dioxide use, final peroxide bleaching was introduced. Prior to peroxide bleaching, different chelating chemicals were applied for comparative analysis in ISO brightness and viscosity. When using equal total chlorine dioxide usage (4.5%), bleached SCB pulp using chelate and hydrogen peroxide (DEDQP) was reached 86.8% (DTPA), 86.4% (EDTA) ISO brightness, whereas bleached pulp using only hydrogen peroxide (DEDP) reached at 81.2% ISO brightness. Viscosity of DEDQP bleached pulp was 25.6 cPs (DTPA), 25.2 cPs (EDTA), And DEDP bleached pulp was shown 18.0 cPs viscosity. Decreasing of transition metal by chelate process led to improvements in final brightness along with higher viscosity. Due to EDTA is 5-7 times cheaper than DTPA, EDTA is recommended as chelating chemical prior to peroxide bleaching.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권7호
• /
• pp.25-31
• /
• 2013

Hydrogen peroxide takes much of the cost for Fenton reaction applied for treatment of organic contaminants. Therefore, the effective use of hydrogen peroxide makes the technology more cost effective. The effective use of hydrogen peroxide is especially needed in the soil and groundwater remediation where complete mixing is not possible and it takes a long time for reactive species to transport to the fixed target compounds. Stabilization ability for hydrogen peroxide of malonic acid was evaluated in Fenton and Fenton-like reactions in this study. Malonic acid contributes on the stabilization of hydrogen peroxide by weak interaction between iron and the stabilizer and inhibiting the catalytic role of iron. The stabilization effect increased as the solution pH decrease below the $pK_{a1}$. The stabilization effect increased as the concentration of malonic acid increased and the effect was maximized at the malonic acid concentration of about ten times higher than the iron concentration. The model organic contaminant was successfully oxidized in the presence of the stabilizer but the degradation rate was slower than the system without the stabilizer. The stabilization effect was also proved in a Fenton-like reaction where magnetite and hematite were used instead of soluble iron species.

• 펄프종이기술
• /
• 제45권1호
• /
• pp.6-12
• /
• 2013

TFormic acid-hydrogen peroxide (or performic acid) pulping process needs milder reaction condition than other chemical pulping process. Two-step formic acid-hydrogen peroxide pulping process can produce the chemical pulp with similar pulp yield and lignin content compared with soda-anthraquinone process. Formic acid-hydrogen peroxide pulp can be produced less xylan content than other alkaline pulps, which favor for dissolving pulp production. Formic acid-hydrogen peroxide pulp showed better response beating than soda-anthraquinone(AQ) pulps with reaching target freeness with less beating. Also, formic acid-hydrogen peroxide pulp had better tensile index at similar freeness level compared with soda-AQ pulps.