• Corrosion Science and Technology
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• 제21권5호
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• pp.412-417
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• 2022

Proton exchange membrane fuel cells (PEMFCs) provide zero emission power sources for electric vehicles and portable electronic devices. Although significant progresses for the widespread application of electrochemical energy technology have been achieved, some drawbacks such as catalytic activity, durability, and high cost of catalysts still remain. Pt-based catalysts are regarded as the most efficient catalysts for sluggish kinetics of oxygen reduction reaction (ORR). However, their prohibitive cost limits the commercialization of PEMFCs. Therefore, we proposed a NiCo@Au core shell structure as Pt-free ORR electrocatalyst in PEMFCs. NiCo alloy was synthesized as core to introduce ionization tendency and autoxidation reaction. Au as a shell was synthesized to prevent oxidation of core NiCo and increase catalytic activity for ORR. Herein, we report the synthesis, characterization, electrochemical properties, and PEMFCs performance of the novel NiCo@Au core-shell as a catalyst for ORR in PEMFCs application. Based on results of this study, possible mechanism for catalytic of autoxidation core@anti-oxidation shell in PEMFCs is suggested.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.341-342
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• 2002

Although vegetable oils provide good lubricity, they still need optimization by certain additive technology for practical applications. ZDTP improve antiwear properties of vegetable oils. However the additive performance depends on quality of the base Oil. Antioxidants were applied to prevent the auto-oxidation of vegetable oils. Good synergistic effect of anti-wear and antioxidant additives was confirmed.

• Journal of Acupuncture Research
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• 제32권3호
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• pp.117-126
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• 2015

Objectives : This study was an analysis of the anti-inflammatory, anti-oxidative and skin whitening properties of Gamioncheong-decoctione(GMOCD) extract. Methods : GMOCD(96 g) and 2 L of distilled water were heated at $100^{\circ}C$ for four hours and then concentrated, frozen, freeze-dried, dissolved in distilled water and filtered. The following analysis was completed: cell cytotoxic effect using MTT assay, oxidative products of NO by griess assay, concentration of prostaglandin $E_2(PGE_2)$ by commercially competitive enzyme immunoassay, and cytokines($IL-1{\beta}$, IL-6 and TNF-${\alpha}$) by Bio-Plex$^{(R)}$ Suspension Array System's Bio-Plex Pro$^{TM}$ mouse cytokine, chemokine, and growth factor assay. Anti-oxidative effect was measured using the DPPH method and skin whitening effect using tyrosinase inhibition assay. Results : GMOCD water-extract did not show any toxicity at all doses and cell viability was more than 90 % at all doses. GMOCD water-extract significantly inhibited NO production at doses of 100, 200, $400{\mu}g/ml$, significantly inhibited $PGE_2$ production at doses of 200 and $400{\mu}g/ml$ and reduced the LPS-induced IL-$1{\beta}$, IL-6 and TNF-${\alpha}$ production in a dose-dependent manner. $IL-1{\beta}$ production was significantly reduced at a dose of $400{\mu}g/ml$ and IL-6 production was significantly reduced at doses of 200 and $400{\mu}g/ml$. DPPH free radical scavenging capability had a skin whitening effect rate of more than 50%. Tyrosinase inhibition activity was apparent in a dose-dependent manner. Conclusions : This study suggests that GMOCD water-extract suppressed NO and $PGE_2$ production and inhibited cytokines($IL-1{\beta}$, IL-6 and TNF-${\alpha}$). GMOCD also improved DPPH free radical scavenging capability. GMOCD water-extract increased tyrosinase inhibitory activity in a dose-dependent manner but this was not a statistically significant result.

• 한국응용과학기술학회지
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• 제26권2호
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• pp.213-223
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• 2009

Conventional additives were added to a newly synthesized base oil to create synthetic lubricants. Commercial polyol ester prepared in this laboratory were obtained as esterification of 1,1,1-trimethylol propane and respectively. This newly synthesized base oil had a variable chemical structure that could achieved the following properties; oxidation or thermal stability, low temperature fluidity, and higher flash points. When compared with commercial mineral lubricants, the synthetic lubricants show superior thermal and oxidation stability, and anti-wear properties.

• 대한의생명과학회지
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• 제24권3호
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• pp.263-269
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• 2018

This study aims to investigate the biological activities related to hair loss of short anti-oxidant peptides (DK peptides) $5{\alpha}$-reductase inhibition and anti-oxidation. The series of DK peptides were generated amphipathic helical properties using leucines, lysines and tryptophan residues. Cell viability and free radical scavenging activities were performed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The DK peptides were investigated for inhibitory activity against $5{\alpha}$-reductase. Antioxidant activities were determined by means of, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. All peptides could inhibit $5{\alpha}$-reductase in lipopolysaccharide-stimulated macrophage. In conclusion, DK peptides was suggested as the most attractive ingredients for improving hair loss, because of the high inhibitory against $5{\alpha}$-reductase inhibition.

• 한국응용과학기술학회지
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• 제40권4호
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• pp.699-709
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• 2023

This study is to establish optimizing condition of alcohol fermentation in vinegar production with aronia, to confirm whether this can be industrially used, and to compare and analyze a change in anti-oxidative activity and quality characteristic according to alcohol fermentation of aronia. The optimized conditions for alcohol fermentation were as follows: Saccharomyces cerevisiae 5645 of yeast strain, a 5% inoculum size, aronia juice with a brix value of 14, and a glucose content of 7%. As a result to conduct scale up with optimizing conditions of alcohol fermentation of aronia, 8 days (192 hrs) of total alcohol fermentation time and 7.4% of the final alcohol content. The harvest volume accounted for approximately 90.2% with a loss of about 2.8%. As a result of antioxidant test, anti-oxidative activity of alcohol fermented liquor is lower than anti-oxidative activity of aronia extract, because of the decrease of antioxidant by oxidation of the fermentation process. However, the decrease of tannin by the fermentation process reduces acerbity of aronia, so increases overall preference

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.27-32
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• 2010

후코이단을 보습제 및 기능성화장품 소재로 사용하기 위한 후코이단 특성 및 그 효과에 대해 연구하였다. 후코이단은 미역 포자엽에서 추출하였다. 화장품 소재 시험으로는 보습력 측정, 항산화(DPPH assay, radical scavenging), 안전성(MTT assay)을 실시하였다. 후코이단의 보습력은 최고의 보습제 중의 하나인 히아루론산의 보습력보다 높았고, 분자량이 감소함에 따라 보습력이 약간 증가하였다. 후코이단은 높은 안전성과 항산화력을 보였다. 후코이단의 보습력 및 항알레르기 효과를 평가하기 위해 아토피 환자 46명에게 후코이단 크림을 6주간 적용하였다. 증상 정도를 나타내는 IGA 값이 3.04에서 2.15로 감소해 39.8%의 증상개선 효과가 있었다.

• 농업과학연구
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• 제48권1호
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• pp.21-31
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• 2021

Yeast strains are capable of hydrolyzing non-digestible saccharides, such as melibiose, raffinose, and stachyose, found in soy meal components. This study revealed the biochemical properties of fermented soybean meal during 72 hours with kefir. Starchyose and raffinose, non-digestible components, were almost digested in kefir 150 mL + soybean meal 500 g + water 70 mL and galactose was produced. Proteolysis of the soybean meal produced most of the small molecule peptides in kefir 150 mL + soybean meal 500 g + water 70 mL. The production of the vitamin B group and C were the highest in kefir 250 mL + soybean meal 500 g. The yeast number of the fermented soybean meal was 7.0 × 10⁶ CFU·mL^-1 which was the highest in kefir 250 mL + soybean meal 500 g. The lactic acid bacteria of the fermented soybean meal was the highest at 3.5 × 10⁹ CFU·mL^-1 in kefir 70 mL + soybean meal 500 g. The antioxidant effect was the highest at 57% in kefir 250 mL + soybean meal 500 g. Expression of inflammation-related cytokine (interleukin [IL]-1β, tumor necrosis factor [TNF]-α, and interleukin [IL]-6) was significantly inhibited in fermented soybean meals with different treatments. These results suggest that fermented soybean meal by kefir has an antiinflammatory and anti-oxidation activity and could be utilized in feed manufacturing, and inhydrolyzing non-digestible soy meal components.

• 대한화장품학회지
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• 제32권1호
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• pp.23-28
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• 2006

본 연구는 택사의 화장품 원료로서의 특성을 알아보기 위하여 화장품의 기능들인 항산화, 미백, 세포 손상 회복 및 항염증과 관련된 다양한 실험을 실시하였다. 30, 70, 100% MeOH 용매로 추출한 택사 추출물들은 DPPH법으로 실시한 free radical scavenging assay에서 좋은 활성을 보여주었고, tyrosinase 활성 억제 시험에서도 0.5% 이상의 농도에서 농도 의존적인 활성을 보여주었다. Human fibroblast를 사용한 proliferation assay (MTT assay)에서 각 용매 추출물들은 별다른 효과를 보여주지 못했고 0.05% 이하의 농도에서는 세포 독성으로부터 안전하다는 것을 알 수 있었다. Bl6 melanocyte를 사용한 melanin 생성 억제시험에서 각 용매별 추출물은 독성으로부터 안전한 0.05% 이하의 농도에서 melanin 생성을 40% 이상 억제하는 높은 활성을 보여주었다. 이후 우리는 택사 추출물의 MPLC분리 분획을 실시하여 세 가지 분획을 얻었으며 이들을 대상으로 세포 손상 회복시험과 melanin생성 억제 시험, 염증인자 생성 억제 시험을 실시하였다. 그 결과 분획물들 중 3번 분획물이 세포 손상 회복을 30% 이상 올려주는 좋은 결과를 보여주었고, melanin 생성 억제 시험과 COX-2 생성억제에서도 주목할만한 결과를 보여주었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제46권2호
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• pp.25-33
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• 2023

The liver, a multifunctional organ, plays a vital role in maintaining overall health and well-being by regulating metabolism, detoxification, nutrient storage, hormone balance, and immune function. Liver diseases, such as hepatitis, cirrhosis, fatty liver disease, and liver cancer, have significant clinical implications and remain a global health concern. This article reviews the therapeutic potential of silkworm larvae (Bombyx mori) and explores their underlying molecular mechanisms in protecting against liver diseases. Silkworm larvae are rich in proteins, vitamins, minerals, and n-3 fatty acids, making them a promising candidate for therapeutic applications. The anti-inflammatory mechanisms of silkworm larvae involve modulating the production of cytokine such as TNF-α and interleukins, inflammatory enzymes including cyclooxygenase-2 and macrophage polarization, thereby attenuating liver inflammation. Silkworm larvae also exhibit anti-oxidative effects by scavenging free radicals, reducing intracellular reactive oxygen species and enhancing the liver's antioxidant defense system. Moreover, silkworms have been reported to decrease the serum alcohol concentration and lipid accumulation. Understanding the therapeutic properties of silkworm larvae contributes to the development of innovative strategies for liver injury prevention and treatment. Further research is warranted to elucidate the precise signaling pathways involved in the anti-inflammatory and anti-oxidative effects of silkworm larvae, paving the way for potential therapeutic interventions in liver diseases.