• Title, Summary, Keyword: anti-oxidants

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A study on insulation Characteristics of XLPE by various additives (다양한 첨가제에 따른 가교폴리에틸렌의 절연특성 분석)

  • Song, Sang-Min;Kim, Gyu-Sik;Son, Won-Keun;Ryu, Boo-Hyung;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.193-196
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    • 2001
  • XLPE is occasionally happened to deteriorate cable insulation characteristics. It is happened to do a breakdown state by the degradation of electrical characteristic and electrical breakdown strength. I prepared TR-XLPE (Tree-Retardant XLPE) as adding various additives to prevent its states. Various additives are treeing retardants, anti-oxidants. Treeing retardants three kinds of aromatic compounds as adding each additive. Anti-oxidants use quinone compound and cresol compound as adding each additive. In order to observe each electrical characteristics, I measured breakdown strength, relative dielectric constant$({\varepsilon}_r)$, dielectric loss tangent$(tan{\delta})$. TR-XLPE specimens as adding treeing retardants and anti-oxidants enhance breakdown strength, ${\varepsilon}_r$, $tan{\delta}$ than pure XLPE.

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The Study of Facial Hair Weakening Ability Using Urea or Anti-oxidants for Shaving (우레아 및 항산화제를 이용한 면도를 위한 수염 강도 약화 연구)

  • Kim, Il Gu;Han, Na Kyung;Kim, Sun Young;Han, Jong Sub
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.42 no.3
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    • pp.279-284
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    • 2016
  • In this study, facial hair weakening ability of urea and anti-oxidants for shaving was investigated. The hair weakening ability and cross-section increase of hair depends on concentration of urea. The results showed that urea affects swelling of hair and this is related to the hair weakening ability. Anti-oxidants showed outstanding weakening ability despite of their low concentrations by breaking disulfide bond in facial hair. To evaluate the suitability of urea and anti-oxidants for facial cosmetic products, in vitro safety tests were proceeded. The results showed that urea and glutathione were safe for face. As a result, urea and glutathione were safe and outstanding as hair weakening agent for cosmetic shaving products.

Investigations on Eco Friendly Insulating Fluids from Rapeseed and Pongamia Pinnata Oils for Power Transformer Applications

  • Thanigaiselvan, R.;Raja, T. Sree Renga;Karthik, R.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.6
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    • pp.2348-2355
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    • 2015
  • Transformer mineral oil which is normally hydrocarbon based is non- biodegradable and pollutes the environment in all aspects. Though vegetable oils are eco-friendly in nature and potentially could be used in transformers as a replacement for the mineral oil, there usage is restricted because of their oxidative instability. The present work focuses on using rapeseed oil and pongamia (pongamia pinnata) oil as effective alternatives for the traditional mineral oil in power transformer. The oxidative stability of the rapeseed oil and pongamia oil is increased by using combinations of the natural and synthetic anti-oxidants as additives. The parameters like breakdown voltage, viscosity, flash point, fire point are measured for the rapeseed oil and pongamia oil with and without the additives as per IEC and ASTM standards. The results shown encouraging changes in the parameter values and ensures the use of the oils as a potential alternative insulation in power transformers.

In Vitro Maturation of Bovine Follicular Oocytes (소 미성숙 난포란의 체외성숙)

  • 문승주;김은국;김광현;선상수;명규호;김재홍
    • Journal of Embryo Transfer
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    • v.15 no.1
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    • pp.39-46
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    • 2000
  • This study was conducted to investigate the effect of hormones, protein sources and anti-oxidants on in vitro maturation (IVM) and in vitro fertilization(IVF) of bovine follicular oocytes. The rates of Holstein follicular oocytes classified as grade A and B(50.2% and 33.2%) were higher than those of Hanwoo cattle(40.3% and 32.0%, P<0.05). The cumulus cell expansion rates of oocytes cultured in TCM-199 and Ham's F-10 medium supplemented with 10% FCS and hormones were higher (81.9~87.6%) than those of non-treated groups (74.5~81.7%). The fertilization rates of oocytes cultured in TCM-199 and Ham's F-10 medim supplemented with 10% FCS, 1% BSA and 10% bFF was 53.8~55.0%, 51.4~52.6%, and 47.0~50.0%, respectively. The polyspermy rates was 13.6~14.2%, 10.0~11.1%, and 10.0%, respectively. When the oocytes were cultured in TCM-199 and Ham's F-10 medium with 50${\mu}{\textrm}{m}$ $\alpha$-tocopherol, the fertilization rates was 62.0 and 60.2%, respectively. In the maturation medium added of 100${\mu}{\textrm}{m}$ cysteamine, the fertilization rates was 64.7 and 66.7%, respectively. The fertilization and polyspermy rates of treated groups were higher than those of non-treated group. The results show that hormones, protein sources and anti-oxidants can provide a benefit for in vitro maturation and fertilization of bovine follicular oocytes.

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Effect of Yeonsan Ogye bioactive peptides on anti-oxidant indexes in rats' liver

  • Kim, Hye Won;Shim, Jung Hun;Kim, Ki Nam
    • Journal of Nutrition and Health
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    • v.52 no.4
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    • pp.408-411
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    • 2019
  • Purpose: This study investigated the effect of bioactive Yeonsan Ogye peptides (YOPs) intake on changes in the hepatic anti-oxidant indexes in male rats. Methods: Sprague-Dawley male rats were divided into 3 groups and given a casein-based AIN-93G diet and distilled water ad libitum without any added YOPs (control), distilled water with 250 mg of YOPs (Y250), or 500 mg of YOPs (Y500) per kg of body weight for 4 weeks. YOP dose was decided as referred to in the referenced study where toxicity did not occur. The hepatic anti-oxidant indexes were determined using a commercial kit. Statistical analysis was performed using SPSS version 23.0 and are expressed as $mean{\pm}standard$ error of mean. Differences among the groups were evaluated by one-way analysis of variance followed by post hoc Duncan's multiple comparisons test. Results: There were no differences in the body weights, weight gain, food intake, food efficiency ratio, or organ weight, including liver, kidney, spleen, thymus, and epididymal fat, among all of the groups. The hepatic nitric oxide (NO) level in the Y500 group was lower than that in the control and Y250 groups, and the hepatic malondialdehyde (MDA) level was lower in the Y500 group than in the Y250 group. The differences in hepatic superoxide dismutase (SOD) and catalase (CAT) activities were not statistically significant between the groups. From these results we speculated that YOPs may have anti-oxidative abilities to regulate NO and MDA production without affecting SOD and CAT activities. Conclusion: YOPs are presumed to act as anti-oxidants in the animal or human body.

Ursolic acid in health and disease

  • Seo, Dae Yun;Lee, Sung Ryul;Heo, Jun-Won;No, Mi-Hyun;Rhee, Byoung Doo;Ko, Kyung Soo;Kwak, Hyo-Bum;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.3
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    • pp.235-248
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    • 2018
  • Ursolic acid (UA) is a natural triterpene compound found in various fruits and vegetables. There is a growing interest in UA because of its beneficial effects, which include anti-inflammatory, anti-oxidant, anti-apoptotic, and anti-carcinogenic effects. It exerts these effects in various tissues and organs: by suppressing nuclear factor-kappa B signaling in cancer cells, improving insulin signaling in adipose tissues, reducing the expression of markers of cardiac damage in the heart, decreasing inflammation and increasing the level of anti-oxidants in the brain, reducing apoptotic signaling and the level of oxidants in the liver, and reducing atrophy and increasing the expression levels of adenosine monophosphate-activated protein kinase and irisin in skeletal muscles. Moreover, UA can be used as an alternative medicine for the treatment and prevention of cancer, obesity/diabetes, cardiovascular disease, brain disease, liver disease, and muscle wasting (sarcopenia). In this review, we have summarized recent data on the beneficial effects and possible uses of UA in health and disease managements.

Studies on Pharmaceutical Effects of Dendropanax morbifera Lev.

  • Baek, Woon-Bong;Choung, Se-Young
    • Proceedings of the PSK Conference
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    • pp.160.2-161
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    • 2003
  • Hwang Chil (Dendropanax morbifera Lev.) belongs to Aralia elata group. This plant is only found in Korea and is considered to be along with ginseng. The physiological activities of it have been reported as having scavenging effect on oxygen free radicals and anti-carcinogenic effect. As most of the anti-oxidants were effective on protecting hepatotoxicity from alcohol, hard tissues restoring and skin whitening, the effectiveness of Hwang Chil extracts was screened. (omitted)

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Anti-Oxidant, Pro-Oxidant and Anti-Inflammatory Effects of Unpolished Rice Relevant to Colorectal Cancer

  • Suwannalert, Prasit;Payuhakrit, Witchuda;Koomsang, Thidarat
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5047-5056
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    • 2016
  • Colorectal cancer (CRC) is a major worldwide health problem owing to its high prevalence and mortality rates. Carcinogenesis in the colon is a multistage and multifactorial process. An imbalance between free radical exposure and anti-oxidant defense systems may leads to oxidative stress and attack of macromolecules which can alter signal transduction pathways and gene expression. Consequently, oxidative damage can lead to cellular dysfunction and contribute to pathophysiological processes in a variety of diseases including CRC. One factor tightly associated with CRC is chronic inflammation, which can be present from the earliest stage of tumor onset. Unpolished rice is an attractive chemoprevention in CRC due to their anti-oxidant and anti-inflammatory activities. The aim of this paper is to review evidence linking oxidative stress and inflammation to CRC and to provide essential background information for understanding future research on oxidative stress and inflammation on CRC. Mechanisms of action of unpolished rice in CRC carcinogenesis are also discussed.

Screening of Anti-oxidants Isolated from Natural Products on V79-4 Hamster Lung Fibroblast Cells Induced by Oxidative Stress (산화적 스트레스로 유도된 V79-4 햄스터 폐 섬유아세포에 대한 천연물 분리 항 산화물질 탐색)

  • Kang, Kyoung-Ah;Jo, Su-Hyun;Koh, Young-Sang;Kim, Jin-Sook;Hyun, Jin-Won
    • Korean Journal of Pharmacognosy
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    • v.36 no.1
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    • pp.34-37
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    • 2005
  • Reactive oxygen species (ROS) are known to cause oxidative modification of DNA, proteins, lipids and small cellular molecules and are associated with tissue damage and are the contributing factors for inflammation, aging, cancer, arteriosclerosis, hypertension and diabetes. We screened the anti-oxidants in V79-4 hamster lung fibroblast cells induced by hydrogen peroxide with eighteen pure compounds isolated from natural products. Allantoin, brassicasterol, and hypaconitine were found to strongly scavenge intracellular reactive oxygen species, which is measured by dichlorodihydrofluorescin diacetate method (DCHF-DA), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.

Effect of Sunlight on the Rancidity of Soybean Oil (대두유의 산패에 미치는 일사광선의 영향)

  • 임국이
    • Journal of the Korean Home Economics Association
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    • v.19 no.1
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    • pp.33-37
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    • 1981
  • The accelerating effect of sunlight on the rancidity of soybean oil and the efficacies of several anti-oxidants were measured. The result is as follows: 1. The ac야 value and peroxide value of soybean oil were 0.16 and 1, 72 respectively. 2. the peroxide value of soybean oil which was exposed to sunlight nine hours a day for six days was 134.3: 21 times of that which was not exposed to sunlight. 3. The peroxide value of the soybean oil with 0.02~0.06% BHA decreased a little, but not significantly. 4. The anti-rancidity effect of BHT was a little stronger than BHA. 5. The anti-rancidity effect of ascorbic acid alone was negligible. 6 The peroxide value of soybean oil with an anti-oxidant which comprised ascorbic acid, BHA and BHT decreased to one third of that which was not treated with anti-oxidant.

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