• Toxicological Research
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• 제33권3호
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• pp.219-224
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• 2017

Lipin1 was identified as a phosphatidate phosphatase enzyme, and it plays a key role in lipid metabolism. Since free radicals contribute to metabolic diseases in the liver, this study investigated the effects of free radicals on the regulation of Lipin1 expression in Huh7 and AML12 cells. Hydrogen peroxide induced mRNA and protein expression of Lipin1 in Huh7 cells, which was assayed by quantitative RT-PCR and immunoblotting, respectively. Induction of Lipin1 by hydrogen peroxide was confirmed in AML12 cells. Hydrogen peroxide treatment significantly increased expression of sterol regulatory element-binding protein (SREBP)-2, but not SREBP-1. Moreover, nuclear translocation of SREBP-2 was detected after hydrogen peroxide treatment. Hydrogen peroxide-induced Lipin1 or SREBP-2 expression was significantly reduced by N-acetyl-$\small{L}$-cysteine treatment, indicating that reactive oxygen species (ROS) were implicated in Lipin1 expression. Next, we investigated whether the hypoxic environments that cause endogenous ROS production in mitochondria in metabolic diseases affect the expression of Lipin1. Exposure to hypoxia also increased Lipin1 expression. In contrast, pretreatment with antioxidants attenuated hypoxia-induced Lipin1 expression. Collectively, our results show that ROS activate SREBP-2, which induces Lipin1 expression.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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• pp.102-105
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• 2007

본 연구에서는 과산화수소 분해 반응을 이용한 초소형 추력기에 대한 성능 평가 실험을 수행하였다. 촉매 베드로는 질량 대 면적 비가 큰 다공성의 세라믹 물질($Isolite^{(R)}$)을 사용하였다. 14%wt의 백금이 촉매로서 촉매 베드에 코팅되었고, 단일추진제로는 85% 과산화수소를 사용하였다. 촉매 베드의 길이와 과산화수소의 가압 압력을 변수로 정하였다. 모든 실험은 콜드 스타트 조건에서 30초간 수행되었다. 매 실험마다 압력을 측정하여 $c^*$ 효율을 계산하였다. 촉매 베드의 길이가 30 mm이고 가압압력이 5.51 bar일 때 95% 이상의 만족스러운 $c^*$ 효율을 보였다.

• Journal of Microbiology
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• 제44권2호
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• pp.206-216
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• 2006

In this study, we have attempted to characterize the functions of YlaC and YlaD encoded by ylaC and ylaD genes in Bacillus subtilis. The GUS reporter gene, driven by the yla operon promoter, was expressed primarily during the late exponential and early stationary phase, and its expression increased as the result of hydrogen peroxide treatment. Northern and Western blot analyses revealed that the level of ylaC transcripts and YlaC increased as the result of challenge with hydrogen peroxide. A YlaC-overexpressing strain evidenced hydrogen peroxide resistance and a three-fold higher peroxidase activity as compared with a deletion mutant. YlaC-overexpressing and YlaD-disrupted strains evidenced higher sporulation rates than were observed in the YlaC-disrupted and YlaD-overexpressing strains. Analyses of the results of native polyacrylamide gel electrophoresis of recombinant YlaC and YlaD indicated that interaction between YlaC and YlaD was regulated by the redox state of YlaD in vitro. Collectively, the results of this study appear to suggest that YlaC regulated by the YlaD redox state, contribute to oxidative stress resistance in B. subtilis.

• The Korean Journal of Physiology and Pharmacology
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• 제11권5호
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• pp.171-174
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• 2007

Neuronal death is a common characteristic hallmark of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases, whereas oriental medicinal plants have to possess valuable therapeutic potentials to treat neurodegenerative diseases. In the present study, in an attempt to provide neuroprotective agents from natural plants, 80% methanol extracts of a wide range of medicinal plants, which are native to Jeju Island in Korea, were prepared and their protective effects on hydrogen peroxide-induced apoptotic cell death were examined. Among those tested, extracts from Smilax china and Saururus chinesis significantly decreased hydrogen peroxide-induced apoptotic cell death. The extracts attenuated hydrogen peroxide($H_2O_2$)-induced caspase-3 activation in a dose-dependent manner. Further, plant extracts restored $H_2O_2$-induced depletion of intracellular glutathione, a major endogenous antioxidant. The data suggest that Jeju native medicinal plants could potentially be used as therapeutic agents for treating or preventing neurodegenerative diseases in which oxidative stress is implicated.

• 전기화학회지
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• 제10권4호
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• pp.235-238
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• 2007

과산화수소의 발생은 일반적으로 유기 산화제를 포함한 산업적 프로세스의 넓은 분야에 응용된다. 과산화수소는 펄프와 제지 공업의 기계적, 화학적 처리를 위하여 사용되고 염소를 기초로 둔 화학제품에 알칼리 처리로 사용된다. 본 연구에서는 Nafiom과 러시아 양이온 교환막인 MK-40, 제조된 SPEEK막을 가스확산전극이 포함된 과산화수소 발생용 전해 셀에서 비교 실험한다. 다른 양성자 교환막에 효과에 따른 과산화수소 발생의 전기화학적 셀의 전압과 전류 효율, 에너지 소모를 연구한다.

• 대한화학회지
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• 제39권12호
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• pp.932-939
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• 1995

시프 염기 구리(II) 착물에 의한 과산화수소 분해속도를 측정하였다. 과산화수소와 구리(II)-시프염기 착물의 반응속도는 $Cu^{II}BSDT$ 및 $Cu^{II}BSTP$인 경우 pH에 따라 증가하였으나 $Cu^{II}BSTT$의 경우 증가하였다가 감소하였다. 이 반응의 메카니즘은 과산화수소의 시프염기 구리(II) 착물의 탈양성자를 거친 다음에 속도결정단계에서 퍼옥소 구리착물이 생성되는 반응과정과 일치한다.

• 약학회지
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• 제54권1호
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• pp.32-38
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• 2010

The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

• 한국의류학회지
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• 제29권11호
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• pp.1454-1464
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• 2005

The study was based on a three-stage, non-repetitive factorial experiment in which chemical-rotted kenaf fibers were treated separately with hydrogen peroxide concentrations of $0.5\%,\;1\%\;and\;2\%$, with pH solutions of 7, 9 and 11, and treatment times of 30, 60 and 90 minutes. Under optimal conditions, the study was conducted to determine the strength and elongation of kenaf fibers by the addition of chelators, penetrants and surfactants. The hydrogen peroxide concentration, solution pH and treatment time directly affected the strength of kenaf fibers. The hydrogen peroxide concentration, solution pH affected the elongation of kenaf fibers. It was found, however, that the interaction between pH and treatment time, concentration and treatment time, concentration and treatment time and pH affected the strength of kenaf fibers. Also, It was found that the interaction between pH and concentration, concentration and treatment time, concentration and treatment time and pH affected the elongation of kenaf fibers. Under the hydrogen peroxide conditions of $2\%$ concentration, pH 11 and a treatment time of 60 minutes, there were no effects on the strength and elongation of kenaf fibers with the addition of chelator SP, CA.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.397-400
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• 2008

기존의 자연점화특성을 지니는 추진제는 성능이 높은 대신 독성이 있으며 다루기 어렵고, 환경에 유해한 단점을 지닌다. 이에 따른 대안으로 과산화수소의 촉매분해 후에 발생되는 고온의 산소와 수증기를 이용한 자연점화 방식이 있다. 이 논문에서는 자연점화 방식의 과산화수소/케로신 추력기를 설계하기 위한 기초연구를 수행하기 위해 자연점화특성을 연구하였다. 추력기의 형상변수로 노즐 목의 면적을 달리하여 연소챔버와의 단면적 비인 수축비를 달리하였으며, flame holder의 유 무, 과산화수소와 케로신의 가압압력에 따른 점화특성 및 연소안정성을 관찰하였다. 그 결과, 대부분의 경우에 자연점화를 관찰할 수 있었으나, 가압압력의 조건에 따라 연소 안정성에는 큰 변화가 있음을 확인할 수 있었다.

• 한국식품영양학회지
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• 제35권4호
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• pp.259-267
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• 2022

The purpose of this study was to evaluate the antioxidative activities of jeolpyun containing Cnidium officinale M extract (2%, 4%, 6%, 8%) by total polyphenol contents, electron donating ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH), scavenging ability of superoxide anion radical and decomposing ability of hydrogen peroxide. In chromaticity analysis, the brightness significantly decreased with increasing Cnidium officinale M extract content. Jeolpyun containing 8% Cnidium officinale M extract revealing the highest value for the redness and the yellowness, 1.07, 12.70, respectively. The total polyphenol contents of jeolpyun containing 8% Cnidium officinale M extract were the highest content of 4,213 ㎍ gallic acid equivalent (GAE)/mL. The total polyphenol contents revealed significant difference (p<0.05). Jeolpyun containing 8% Cnidium officinale M extract revealing the highest electron donating ability (83.55%). The electron donating abilities were significantly related at p<0.05. The scavenging abilities of superoxide anion radical for jeolpyun containing 4% Cnidium officinale M extract revealed the highest ability (0.01676). There was no significant difference. The hydrogen peroxide decomposing ability for jeolpyun containing 8% Cnidium officinale M extract revealed the most hydrogen peroxide decomposing ability (-0.193) and the hydrogen peroxide decomposing ability revealed a significant difference (p<0.05).