• Journal of Sericultural and Entomological Science
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• v.42 no.2
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• pp.93-98
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• 2000

This study was designed to investigate the effect of silkworm powder on oxygen radicals and their scavenger enzymes in brain membrances of SD rats. Hydroxyl radical (OH) levels resulted in a considerable decreases in brain mitochondria fraction. Superoxide radical (O$_2$) levels were a slightly decreased in brain cytosol fraction. Lipid peroxide (LPO) and Oxidized protein (OP) levels were significantly decreased in brain mitochondria and microsomes fraction. Mn-superoxide dismutase (SOD) activity was remarkably increased in the mitochondria fraction. Cu and Zn-SOD activities were effectively increased in brain cytosol fraction. GSHPx activity was considerably increased in brain cytosol fraction. These results suggest that anti-aging effect of silkworm plays an effective role in attenuating an oxidative stress and increasing a scravenger enzyme activity in brain membranes.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.64-69
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• 2004

The deficiency of the neurotransmitter acetylcholine(ACh) is responsible for the initiation of Alzheimer's disease. In addition, there is a simple evidence that oxidative stress significantly increases in persons with Parkinson's disease compared to age-matched healthy persons. Therefore, the objective of the study was to investigate the neurodegeneration inhibitory effect of soybean(Glycine Max) and Yak-Kong(Rhynchosia Nolubilis) by measuring the degree of inhibiting Acetylcholinesterase (AChE) catabolizing the ACh and the free radical scavenger effect in vitro. AChE was measured by the minor modified Ellman assay. Free radical scavenging activity was measured using l-diphenyl-2-picrylhydrazyl (DPPH). First, the MeOH extracts of Soybean and Yak-Kong showed the AChE inhibiting activity of 62.0$\pm$2.43％ and 65.0$\pm$3.29％ at the 5 mg/$m\ell$ concentration. The 50％ inhibitory concentration ($IC_{50}$/) of AChE was 1.96 and 1.31 mg/$m\ell$ in the MeOH extracts of soybean and Yak-Kong. Second, the MeOH extracts of soybean and Yak-Kong showed the free radical scavenger activity of 23.1$\pm$4.26％ and 80.7$\pm$4.61％ at the 5 mg/$m\ell$. IC50 of free radical scavenger activity in Soybean and Yak-Kong was 13.00 and 1.41 mg/$m\ell$ in MeOH extracts and was 5.95 and 2.74 mg/$m\ell$ in hot-water extracts, respectively. In this study, the extracts of Soybean and Yak-Kong showed powerful effects in the AChE inhibition and free radical scavenging. The extracts of Soybean and Yak-Kong were expected to prevent the many neurodegenerative diseases.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.2
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• pp.132-136
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• 2016

Radiolysis is the process of decreasing in Radio-Chemical Purity (RCP) of [$^{18}F$]FDG by direct effect and indirect effect of self Radio-activity. The objective of our study was to figure out the ideal conditions which minimize damages of quality of [$^{18}F$]FDG using radical scavenger and controlling temperature of storage.

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.26-33
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• 1989

Nineteen flavonoids, five phenolics, two coumarins, maltol and L-ascorbic acid were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds. Many were found to be potent scavenger and the five most potent ones were (+)-catechin, (-)-epicatechin, phloroglucinol, caffeic acid and L-ascorbic acid. The nitrite scavenging effect was higher at pH 1.2 than pH 3.0 and increased when the incubation time was longer. The possible relationship of structures to scavenging effect of the flavonoids tested was discussed.

• Journal of Life Science
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• v.8 no.1
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• pp.91-96
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• 1998

Pine(Pinus densiflora Sieb et Zucc.) is one of rhe popular plant drugs which has been used as a medicine in Asia. To investigate the effect of pine needle extract (PNE) on oxygen radicals and their scavenger enzymes in brain membranes of Sprague- Dawley (SD), make SD rats were fed basic diets(control group), and experimental diets (PNE group) with 0.5 and 1.0% of PNE 6 weeks. Mitochondrial hydroxyl radical levels in brain of 0.5%-PNE and 1.0%-PNE groups were significantly inhibited to 30% and 25%, respectively, and microsomal hydrogen peroxide levels in brain of 0.5%-PNE and 1.0%-PNE groups were significantly inhibited to 15% compared with control group. Cytosolic superoxide rdical levels in 1.0%-PNE group were significantly inhibited to 20% compared with control group. Lipid peroxide(LPO) levels in brain mitochondria of 0.5%-PNE and 1.0%-PNE groups were significantly lower(25% and 35%) than that in control group. Mn-superoxide disumtase (SOD) activities in brain of 0.5%-PNE and 1.0%-PNE groups were significantly higher(18% and 12%) than those in control groups, but Cu,Zn-SOD activities in brain of 0.5%-PNE were significantly activated to 15% compared with control group. Glutathione peroxidase(GSHPx) activities in brain of 1.5%-PNE and 1.0% PNE groups were significantly higher(14% and 12%) than those in control group. These results suggest that more beneficial effects such as inhibition of oxygen radicals and lipid peroxide(LPO). and oncreases of scavenger enzymes in brain membranes of SD rats may be effectively modulated by administration of pine needle extract (PNE)

• Journal of Life Science
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• v.9 no.4
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• pp.466-472
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• 1999

These studies were designed to investigate the effects of pine (Pinus densiflora Sieb et Zucc.) needle extract (PNE) on oxygen radicals and their scavenger enzymes in liver membranes of Sprague-Dawley (SD) rats as a study on investigation of anti-aging effect and determination of chemical structures of PNE through the animal experiments. Male SD rats were fed basic diets (control group) and experimental diets (0.5% and 1.0%-PNE group) for 6 weeks. There were no significant differences in hydroxyl radical (·OH) formations of liver mitochondria and microsomes in 0.5%-PNE group, while ·OH formations were significantly decreased (10% and 18%, respectively) in liver mitochondria and microsomes of 1.0%-PNE group compared with control group. Microsomal hydrogen peroxides and cytosolic superoxide radicals were remarkably decreased (20% and 20∼25%, respectively) in 0.5% and 1.0%-PNE groups compared with control group. Mn-SOD activities in mitochondria were significantly increased about 10% in 1.0%-PNE group, while Mn-SOD activities in mocrosomes were remarkably increased (16∼20%) in 0.5% and 1.0%-PNE groups compared with control group. There were no significant differences in Cu, Zn-SOD activities of liver cytosol in 0.5% and 1.0%-PNE groups, while glutathione peroxidase (GSHPx) and catalase (CAT) activities were significantly decreased (28∼30% and 15∼30%, respectively) in liver cytosols of 0.5% and 1.0%-PNE groups compared with control group. These results suggest that these PNE may play a effective role in a attenuating a oxygen radical formations and increasing a scavenger enzyme activities.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.3
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• pp.71-81
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• 1986

In order to control the formaldehyde release from D.P. finished fabric, cotton fabric was padded in DMDHEU resin bath containing either $Zn(NO_3)_2$ or $MgCl_2$ catalyst and a form-aldehyde scavenger like Glycerol, Sorbitol, Formamide, Polyvinyl alcohol (PVA, n= 2000) or diols, then dried and cured. The results are as follows : 1. When Lewis acid catalyst like $Zn(NO_3)_2$ or $MgCl_2$ was added in pad bath, the fabric finished with $Zn(NO_3)_2$ catalyst released the lower formaldehyde than with $MgCl_2$. 2. When the effect of pad bath pH was examined with varying the kinds of catalyst and the scavenger, it was found that the pad bath pH influenced on the amount of formaldehyde release and the optimum pad bath pH is at 4.3. Especially, in case of finishing at pad bath pH 4.3 with adding Formamide, the amount of formaldehyde release was decreased by about $45\~$35\%$ with $Zn(NO_3)_2$, while by about $20\~$45\%$ with $MgCl_2$ catalyst. In case of varying the concentration of a scavenger (Formamide), $1\%$ concentration of a scavenger was found to be the optimum level ana the higher the curing temperature up to $180^{\circ}C$, the lesser the amount of formaldehyde release were observed. 3. When the diol was used as scavenger, the amount of formaldehyde release was decreased by about $40\~$50\%$, but the longer the intramolecular length between OH groups, the lessor the amount of decrease of formaldehyde release were observed. 4. When the mixture of scavengers (Formamide and Glycerol) was added in the pad bath, .synergistic effect on formaldehyde release between the two scavengers wasn't observed. 5. The tensile strength of the resin finished fabric was reduced with increasing the pad lath pH and was influenced by the kind of scavengers, and the tensile strength was severely reduced when scavengers, especially Formamide, was added. The wrinkle recovery property is generally improved by resin finish on cotton fabric. When Formamide was added, the wrinkle recovery property is slightly decreased compared with that of the fabrics resin finished without a scavenger, and when polyol was added, the wrinkle recovery property showed almost no change.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.59-63
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• 2020

Radical scavenger is used to improve the durability of PEMFC polymer membrane. In this study, we investigated whether fucoidan extracted from seaweed as a radical scavenger prevents electrochemical degradation through Fenton and OCV Holding experiments. Fucoidan has an antioxidant effect, protecting the polymer membrane from hydrogen peroxide and oxygen radicals, reducing the degradation rate to 1/10. Fucoidan has been shown to be more effective than MnO₂, which is used as a radical scavenger. In the PEMFC cell, the accelerated durability evaluation method (OCV Holding) showed that fucoidan reduced the hydrogen permeability of the polymer membrane by 12% and enhanced the performance by 29.1% compared to without radical scavenger. And fucoidan was found to be more effective in the cathode side ionomer than the anode side.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.508-513
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• 2021

In order to improve the durability of a proton exchange membrane fuel cells (PEMFC), it is essential to improve the durability of the polymer membrane. In order to improve the durability of the membrane, an e-PTFE support and a radical scavenger are added. In this study, the chemical durability of the reinforced membrane with ePTFE support and the non-reinforced membrane was compared by Fenton reaction. In the Fenton experiment of the polymer membrane without the addition of a radical scavenger, the absorption rate of hydrogen peroxide solution and iron ions through the cross section of the specimen cut into small pieces was higher in the reinforced membrane, so that the fluorine outflow concentration was higher. According to the type and amount of radical scavenger added, the fluorine outflow concentration of the reinforced membrane has a large difference of more than 3 times, indicating that the effect of the radical scavenger was stronger than that of the support.

• Tribology and Lubricants
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• v.4 no.1
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• pp.36-42
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• 1988

On the basis of the thermally-activated Wear theory, it is well estabilished that the secondary activated energy, which is mainly resulted from the exothermic reaction of hydrogen from thermal decomposition of the hydrocarbons at the high temperature and the high speed, caused catastropic failure. The new additive, viz., DEP was synthesized to reduce or eliminate the hydrogen effect at the contact junction. Through the thermal degrading and the thermodynamic consideration, the synthesized additive, viz., DEP showed the possibiliy as the hydrogen scavenger.