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Keum Y.-S.,Dongguk University | Choi B.Y.,Seowon University
Molecules | Year: 2014

Extracellular and intracellular oxidants or electrophiles are key contributors to the damages in cellular macromolecules, such as DNA, proteins and lipids. Nrf2 is a master transcription factor that modulates a cellular antioxidant response program and plays an important role in the protection against oxidants and electrophiles. Keap1 is a regulator of Nrf2 by serving as a substrate adaptor for Cullin3-dependent E3 ubiquitin ligase. While Nrf2 activation is a feasible strategy for treatment of age-related diseases, aberrant Nrf2 activation also confers a selective growth advantage of tumor cells during chemotherapy or radiotherapy. In the present review, we provide an overview of the Keap1-Nrf2-ARE system, the domain organization of Nrf2 and Keap1, and the regulatory mechanisms of Nrf2 proteolysis by Keap1. We also discuss how Nrf2 prevents tumor promotion, hampers the sensitivity of selected tumors against chemotherapy or radiotherapy, and reprograms the metabolism to facilitate the tumor proliferation. Finally, we illustrate the current status in the development of Nrf2 chemical activators and inhibitors for the use of potential chemopreventive agents and chemotherapeutic adjuvants, respectively.

The purpose of this study is to examine the relationship between the protein supplements intake satisfaction level and repurchase intention of university students majoring in physical education and verify the mediation effects of word-of-mouth intention. To achieve the purpose of this study, 700 university students majoring in physical education from 10 universities in Korea were selected from October 2013 to December 2013 as the target of this study through the cluster random sampling and data of 228 university students who had experience in the intake of protein supplements among them was analyzed. The composite reliability of each factor was in between 0.869 and 0.958, and the convergent validity and discriminant validity were verified. SPSS 18.0 and Amos 22.0 were utilized as data processing methods and the verification of significance on the medication effects and indirect effects of word-of-mouth intention was carried out using the frequency analysis, correlation analysis, CFA, SEM, and Amos bootstrapping. The result is as follows. The protein supplements intake satisfaction level had a positive effect on the word-of-mouth intention and the word-of-mouth intention had a positive effect on the repurchase intention. Also, it was shown that the word-of-mouth intention played a full mediation role between the intake satisfaction level and the repurchase intention. © 2016 - IOS Press and the authors. All rights reserved.

Kim C.H.,Seowon University
Journal of Applied Biological Chemistry | Year: 2014

A gene encoding thermostable pectinase (TmPec) was isolated from hyperthermophilic microorganism, Thermotoga maritima. The open reading frame (ORF) of TmPec gene is 1,104 bp long and encodes 367 amino acid residues with a molecular weight of 40,605 Da. To analyze the enzymatic activity and biochemical properties, the ORF of TmPec gene excluding putative signal sequence of 27 amino acids was introduced into the E. coli expression vector, pRSET-B, and overexpressed in E. coli BL21. Protein concentration of purified recombinant TmPec was 1.1 mg/ mL with specific activity of 56 U/mg protein on pectin. The recombinant TmPec showed the highest activity at around 85-95°C, and at around pH 6.5. It was stable at temperature below 85°C. In the presence of Ca2+, the activity of recombinant TmPec was increased to 146.3% of normal level. In contrast, Ba2+ and Mn2+ showed strong inhibition to the recombinant TmPec. © The Korean Society for Applied Biological Chemistry 2014.

Food security is one of the dimensions in reducing poverty. Food bank governance is a key system for increasing food security. Even if thousands of food banks operate around the world by importing the standard US model, a universal standard of governance cannot always be applied to all countries, because actors, networks, and institutions embedded in unique social, economic, cultural, and political contexts retain endogenous properties. Hence, the governance model must reflect the endogeneity each society has. This article aims to theoretically suggest the endogenous governance model and to empirically demonstrate the validity of this model by comparing the governance of food banks in the USA and Korea. Although Korea introduced the US food bank model, the Korean model has been adapted and changed, evolving its own system. To find the difference in endogenous food bank governance between the two countries, we compared the variety of governance models, the institutional context, mode of network, actors' attributes, and time perspective. © 2014 International Journal of Social Welfare and John Wiley & Sons Ltd.

Yong L.H.,Seowon University
Research Journal of Biotechnology | Year: 2016

A new microorganism, Lactobacillus acidophilus was isolated from human skin, especially in the hands of women by tree analysis of the amplified 16S rRNA gene. Its morphology was observed as a rodtypelactobacillus through scanning electron microscopy and named Lactobacillus acidophilus HK-9 (KCCM11789P) by the Korea Culture Center of Microorganisms. Because the isolated bacterium was derived from human skin, its cosmeceutical activities were observed revealing a relatively high antioxidant effect as 14.95% of DPPH free radical scavenging ability and also 18.26% of inhibiting tyrosinase activity as well 55.10% of inhibiting melanin synthesis. It was also confirmed that these cosmeceutical activities were similar to or even better than those from other natural herbs which can strongly indicate that a newly isolated Lactobacillus acidophilus HK-9 could be used as an alternative cosmeceutical whitening agent.

The increased globalization of the food trade has led to the safety of imported food becoming a critical issue for both importing and exporting countries. Significant differences in the food control systems of importing countries remain despite the international guidelines issued by the Codex Alimentarius Commission. This paper provides an overview of the imported food control measures in four countries/regions, namely, the Republic of Korea, Japan, the United States (US), and the European Union (EU). By comparing their systems, it finds that a paradigm shift of imported food safety control is occurring in the Republic of Korea. If both the registration and the on-site inspection of foreign facilities are introduced in the future, in line with the Imported Food Safety Special Bill, the Korean system will move closer to the US approach of preferring direct control, in contrast to the systems in Japan and the EU. This paper thus concludes that equivalence is a key factor to explain the phenomena. Copyright © Taylor & Francis Group, LLC.

Kim M.-K.,Seowon University
Korean Journal of Food Science and Technology | Year: 2016

To determine the optimum condition for the extraction of active components, noni adventitious roots were extracted under various conditions employing various solvents including methanolic water at different ratio (20, 40, 60, 80, and 100% water), extraction times and extraction methods. Anthraquinones, phenolic compounds, and flavonoids extraction using different solvents showed that 1 h of ultrasonic extraction was effective in 60-80% methanol, and 2 h of reflux extraction was effective in 80% methanol. To compare the extraction efficiency of active components according to different extraction methods and extraction times for noni adventitious roots, the active components were extracted by ultrasonic extraction, shaking extraction, reflux extraction, homogenizer extraction, high-pressure extraction, and soaking extraction. The highest phenolic contents were found in the extracted from ultrasonic extraction and anthraquinones and flavonoids contents were highest in the reflux extraction.

Yong L.H.,Seowon University
Research Journal of Biotechnology | Year: 2016

856, 1137 and 2100 kiloDaltons (kD) of three acidic polysaccharides were obtained from the Ginsengs through a simple one-step homogenization process at 30000 psi with two cycles for 30 min. Of these three polysaccharides, the 1137-kD polysaccharide showed the highest skin anti-inflammatory activities, increasing both human B and T cell growth up to 1.5×105 viable cells/mL. These polysaccharides also showed the ability of regulating iNOS gene expression down to 65% as compared to the case of treating lipopolysaccharides (LPS). This down-regulation resulted in good suppression of NO production down to 8.22 and 10.23 μM in adding 856 and 2100 k D of the polysaccharides respectively while 12.5 μM of NO production from human macrophage was observed in treating LPS only. In addition, 26.7 pg/mL and 839.1 pg/mL of IL-6 and TNF-α production from human T cells were estimated in treating 1137kD polysaccharide. This polysaccharide was also found to effectively inhibit both hyaluronidase enzyme activities and Prostaglandin E2 (PGE2) production compared to the other two polysaccharides (856 and 2100 kD).These results strongly indicate that 1137kD polysaccharide obtained from the fresh ginseng has better skin anti-inflammatory activities than those of 856 and 2100-kD polysaccharides. Selective polysaccharides from a relatively simple pretreatment process could have high skin anti-inflammatory activities possibly due to the efficient destruction of the crystal structures of the intact large polysaccharides of ginseng with small amounts of the polysaccharide sulfates. © 2016, Research Journal of BioTechnology. All rights reserved.

Hyeon Yong L.,Seowon University
Research Journal of Biotechnology | Year: 2016

The stability of the ethanol extract from Aronia melanocarpa Elliot was studied by being associated with its antioxidant activities according to various storage conditions of temperature, periods and the forms of the extract such as powder and solution. It was interesting that the contents of a major anthocyanin, cyanidin-3-O-galactoside (cya-gal) in the powder were not much changed during the storage period at 250C while those in the solution were decreased after the 4th week of the storage under the same condition. Also, cya-gal contents decreased both in the forms of powder and solution at 400C. In addition, cya-gal contents were not changed for overall storage periods at 40C. The structural changes of cya-gal were also observed by showing significant decrease of UV spectrum at 460∼600 nm wave length during the storageat 400C which was well corresponding to the decrease of pH of the extracts. For the antioxidant activities, DPPH free radical scavenging activity and reducing power of the samples were not much changed at 40C for up to the 5th week of the storage while they were decreased at room temperature and the lowest at 400C by showing great decrease of its activities from the 2nd week of the storage. In this work, it is first reported that the optimal storage condition of Aronia extract was determined at 40C in the form of the power for up to the 6th week of the storage period by simultaneously considering the structural changes and biological activities of cya-gal.

Kang K.,Seowon University
Journal of Information Processing Systems | Year: 2012

We propose an analytic model to compute the station's saturated throughput and packet delay performance of the IEEE 802.11 DCF (Distributed Coordination Function) in which frame transmission error rates in the channel are different from each other. Our analytic model shows that a station experiencing worse frame error rates than the others suffers severe performance degradation below its deserved throughput and delay performance. 802.11 DCF adopts an exponential back-off scheme. When some stations suffer from high frame error rates, their back-off stages should be increased so that others get the benefit from the smaller collision probabilities. This impact is then recursively applied to degrade the performance of the victim stations. In particular, we show that the performance is considerably degraded even if the frame error rate of the victim station satisfies the receiver input level sensitivity that has been specified in the IEEE 802.11 standard. We also verify the analytic results by the OPNET simulations. © 2012 KIPS.

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