• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.12-19
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• 2018

Perilla frutescens (P. frutescens) is one of evergreen shrubs belonging to the Labiatae and is grown wildly in Korea. This study was carried out to evaluate the anti-oxidative effects of Perilla frutescens Extracts by Extraction Methods (water, heating and sonication). Anti-oxidative effects were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenol content. Cell viability and hepatoprotective effects were identified by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. Among various extracts, P. rutescens extracts by sonication showed the highest DPPH radical scavenging activity at $5000{\mu}g/mL$. Total phenolic content in P. frutescens extracts by sonication was $51.60{\pm}1.06mg\;GAE/g$ extract. However, P. frutescens extracts did not show hepatoprotective effects. This study identified anti-oxidative effects of P. frutescens extracts by sonication, and it would be necessary to perform further studies of P. frutescens extracts by sonication.

• Journal of Nutrition and Health
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• v.42 no.4
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• pp.366-373
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• 2009

Codex Nutrient Reference Values (NRVs) were based on the 1988 Helsinki report and a single set of NRVs was established for the general population over 3 years for the purpose of food labeling in 1993. Dietary Reference Intakes (DRIs) with new concepts were developed in many countries recently. Hence there has been broad discussion regarding establishment of new NRVs using DRIs, which include estimated average requirement (EAR), recommended intake (RI or RDA), adequate intake (AI), and tolerable upper intake level (UL) in the world. This study was carried out to review various possible values for Codex NRVs such as population-weighted EAR, population-weighted RDA, and populationbased RDA. The values were simulated using DRIs and population distribution of Korea, USA, Japan, Philippines, Germany and England, and compared to the current Codex values and the highest RDA and the lowest UL among populations with different life-stage. Since population weighted/based values are necessary to be updated according to the population changes and are different across countries, inconsistency can be a serious barrier in international transactions. For some of nutrients such as vitamin A and zinc, values based on population-based RDA or the highest RDA were higher than the lowest UL. Therefore, careful considerations should be given before establishing Codex NRVs.

• Journal of Nutrition and Health
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• v.43 no.6
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• pp.653-660
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• 2010

Along with the steady growth of health functional food (HFF) markets, research evaluating the human effects of HFF has been expanding. In this study, we investigated the regulatory and management system of human study on HFF in the USA, Japan and UK, and the Korean domestic regulations on HHF, medicines, medical devices, cosmetics and biotechnology in order to improve the domestic management system. In these four countries, institutional review board (IRB) or research ethics committee (REC) approvals are required for on human study of HHF, but regulatory and management systems differ from country to country. In the USA, human studies on HFF for structure/function claims do not require the FDA's prior approval but clinical trials of the disease treatment effects of HHF require prior approval from the FDA. In the USA, IRBs are managed by the Department of Health and Human Services (DHHS) rather than the FDA, and IRBs in those institutions which would execute the clinical trials requiring prior approval from the FDA or human studies funded by the USA federal government are required to be registered on the DHHS. In the UK, although the government does not require prior approval of human study, authorized RECs managed by the National Research Ethics Service (NRES) and other independent RECs review the human study. In Japan, human study for HFF must conform with "Ethical guidelines for epidemiological research" and IRB registration has not been required. In Korean domestic regulations, the responsibilities, compositions, functions and operations of IRBs on medicines, medical devices and biotechnology are legally specified, but not those of IRB on HHF. These foreign statuses for the management of human study on HFF and comparisons with Korean regulations are expected to be used as basic data to improve the domestic legal system.

• Journal of KIISE:Information Networking
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• v.34 no.3
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• pp.226-238
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• 2007

In this paper, we present a novel fully distributed topology control protocol that can construct the multiple-ring topology of Minimal Connected Dominating Set (MCDS) as the transport backbone for mobile ad hoc networks. It makes a topology from the minimal nodes that are chosen from all the nodes, and the constructed topology is comprised of the minimal physical links while preserving connectivity. This topology reduces the interference. The all nodes work as the nodes of the distributed parallel Boltzmann machine, of which the objective function is consisted of two Boltzmann factors: the link degree and the connection domination degree. To define these Boltzmann factors, we extend the Connected Dominating Set into a fuzzy set, and also define the fuzzy set of nodes by which the multiple-ring topology can be constructed. To construct the transport backbone of the mobile ad hoc network, the proposed protocol chooses the nodes that are the strong members of these two fuzzy sets as the clusterheads. We also ran simulations to provide the quantitative comparison against the related works in terms of the packet loss rate and the energy consumption rate. As a result, we show that the network that is constructed by the proposed protocol has far better than the other ones with respect to the packet loss rate and the energy consumption rate.

• Nutrition Research and Practice
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• v.6 no.1
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• pp.68-77
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• 2012

Flavan-3-ols are a subclass of flavonoids found in a variety of foods including teas. The effects of flavan-3-ols on the risk of metabolic syndrome (MetS) have been investigated, generally focusing on tea catechins or individual flavan-3-ol rich foods, but there is little information on dietary flavan-3-ols intake and risk of MetS in population-based studies. In this cross-sectional study, we examined the association between dietary flavan-3-ols intake and the risk of MetS in Korean adults. Subjects comprised 1,827 men and 2,918 women aged 20-69 years whose data was included in the 2008 Korean National Health and Nutrition Examination Survey. This survey was conducted between January 2008 and December 2008. Total flavan-3-ols intakes were calculated from 24-hour dietary recalls using a flavonoids database. Thirty percent of the male subjects and 24% of the female subjects were reported as having MetS. In the female subjects, flavan3-ols intake was inversely associated with the risk of MetS after adjusting for potential confounders (5th vs. 1st quintile, OR=0.64, 95% CI=0.45-0.91, P for trend=0.384). The main food source of flavan-3-ols was green tea followed by apples and grapes. Among MetS components, flavan-3-ols intake was inversely associated with the risk of high blood pressure after adjusting for potential confounders (5th vs. 1st quintile, OR=0.64, 95% CI=0.45-0.90, P for trend=0.005). No significant association between flavan-3-ols intake and risk of MetS was found in the male subjects. After stratified analysis by obesity (BMI ${\geq}$ 25 or BMI < 25), however, flavan3-ols intake was inversely related to the risk of hypertension in non-obese men. These results suggest that dietary flavan-3-ols intake may have beneficial effects on MetS risk by reducing the risk of hypertension. The effects of flavan-3-ols intake dependent on obesity need further investigation.

• Nutrition Research and Practice
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• v.4 no.1
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• pp.3-10
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• 2010

This study was performed to investigate the effect of desalinated underground seawater (named as 'magma seawater', MSW) of Jeju Island in Korea on lipid metabolism and antioxidant activity. MSW was collected from underground of Han-Dong in Jeju Island, and freely given to high fat diet (HFD)-fed C57BL/6 mice for 10 weeks. Although there were no significant differences in the body weight changes and plasma lipid levels, hepatic triglyceride levels were significantly lower in the MSW group than in the normal tap water (TW)-drunken control group. Furthermore, the activity of fatty acid synthase (FAS) was significantly decreased and carnitine palmitoyltransferase (CPT) activity was increased in MSW group compared to TW group. Similarly, real-time PCR analysis revealed that mRNA expressions of lipogenic genes were lowered in MSW groups compared to the control group. In a morphometric observation on the liver tissue, accumulation of fats was remarkably reduced in MSW group. Meanwhile, in vitro assay, tree radical scavenging activity measured by using diphenylpicrylhydrazyl (DPPH) was increased in MSW group. The 2'-7'-dichlorofluorescein diacetate (DCF-DA) staining followed with fluorescent microscopy showed a low intensity of fluorescence in MSW-treated HepG2 cells, compared to TW-treated HepG2 cells, which indicated that the production of reactive oxygen species by tert-butyl hydroperoxide (t-BHP) in HepG2 cells was decreased by MSW treatment. The antioxidant effect of MSW on t-BHP-induced oxidative stress in HepG2 cells was supported by the increased activities of intracellular antioxidant enzymes such as catalase and glutathione reductase. From these results, we speculate that MSW has an inhibitory effect on lipogenesis in liver and might play a protective role against cell damage by t-BHP-induced oxidative stress.

• Nutrition Research and Practice
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• v.6 no.6
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• pp.520-526
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• 2012

Various forms of fermented soybean products are well documented for their health benefits. The efficacy of anti-obesogenic effect of Doenjang, one of the most commonly used seasonings in Korean cuisine, has been reported only in animal models; thus, an evaluation of Doenjang needs to be conducted in human studies. We aimed to test the hypothesis that Doenjang supplementation reduces body weight and changes body composition in overweight adults. A total of 51 overweight adults participated in this study. A group of males with BMI ${\geq}23kg/m^2$ and waist to hip ratio (WHR) ${\geq}$ 0.90, and a group of females with BMI ${\geq}23kg/m^2$ and WHR ${\geq}$ 0.85 were randomly assigned to either a Doenjang supplement (9.9 g dry/day) group or a placebo group for a 12-week randomized, double-blind and placebo-controlled study. Anthropometric parameters, abdominal fat distribution by computerized tomography (CT) and blood components were measured before and after the intervention period. After the 12-week study, the Doenjang supplementation group had significant reductions in body weight (kg), body fat mass (kg) and body fat (%) compared to the placebo group, the supplementation of Doenjang resulted in a significant reduction in visceral fat ($cm^2$), although no changes were observed in total and subcutaneous fat are as ($cm^2$), serum lipid profiles and dietary intakes. The present study demonstrated that daily supplementation of 9.9 g dry/day of Doenjang for 12 weeks reduces body weight and visceral fat in overweight adults.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.20-29
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• 2012

Metabolic syndrome (MetS) has become a global epidemic. In particular, it is known that there is a dramatic increase in the prevalence of MetS among women during the postmenopausal period. Recently, accumulating studies have suggested that vitamin D deficiency may be inversely associated with the risk factors regarding MetS. However, evidence from postmenopausal women is limited. In this study, we examined the association between the serum 25-hydroxyvitamin D [25(OH)D] and the MetS in Korean adult women aged 20-69 years (n = 2,618) by using the 2007-2008 Korean National Health and Nutrition Examination Survey data. The geometric mean of plasma 25(OH)D were $17.16{\pm}6.28\;ng$/mL and $20.20{\pm}7.69\;ng$/mL for premenopausal and postmenopausal women, respectively. The percentages of vitamin D deficiency [25(OH)D < 12 ng/mL] were 22.5% and 14.4%, respectively. MetS was more prevalent in postmenopausal women (43.0%) compared with premenopausal women (11.2%). When serum concentrations of 25(OH)D were categorized in quintiles, there was no relationship in the prevalence of MetS in both premonopausal and postmenopausal women. However, in premenopausal women, compared with the lowest 25(OH)D quintile, the odds ratio for hypertriglyceridemia in the highest quintile was 0.57 (95% CI 0.34-0.95, $P_{trend}$ = 0.041) and for low serum HDL cholesterol 0.60 (95% CI 0.42-0.85, $P_{trend}$ = 0.014) after adjusting for all potential confounders. On the other hand, we observed the tendency of an inverse relationship for 25(OH)D regarding low serum HDL cholesterol (OR 0.78, 95% CI 0.50-1.22, $P_{trend}$ = 0.029) and a direct relationship with abdominal obesity (OR 1.94, 95% CI 1.01, 3.74, $P_{trend}$ = 0.049) in postmenopausal women. Further studies are needed to confirm these findings in other research settings.

• Journal of Nutrition and Health
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• v.42 no.8
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• pp.714-722
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• 2009

The principal objective of this study was to determine the effects of leucine on body weight reduction in high fat diet-induced overweight rats. To induce overweight, six-month-old male Sprague-Dawley rats (n = 80) were divided into 8 groups; one group of 10 rats was fed on a normal fat diet and the remaining 70 rats were fed on a high-fat diet (40% of energy as fat) for 14 weeks. Then, 10 rats fed on the normal fat diet and another 10 rats fed on the high fat diet were sacrificed to identify overweight induction. The remaining 60 rats were divided randomly into 6 groups according to body weight and fed on one of the diets with different dietary fat levels (9.6% or 40% of energy as fat) and leucine levels (0, 0.6 or 1.2 g/kg BW) for the following 5 weeks of experiments. The body weight loss in the Leu-administered groups (0.6 g, 1.2 g/kg BW) was significantly higher than those of Leu non-administered groups. The perirenal fat pad weights in the Leu-administered groups were significantly lower than those of the Leu non-administered groups. Of the hepatic enzymes, glucose-6-phosphate dehydrogenase (G6PDH) activities were reduced significantly in the Leu-administered groups than in the Leu non-administered groups. With the oral glucose tolerance test (OGTT), the incremental areas under the curve of the glucose response (IAUC) of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. The fasting glucose concentration and HOMA-IR of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. In conclusion, the results of this study suggest that one of the possible mechanisms of leucine in the observed body weight reduction might involve the inhibition of lipogenic enzyme activities such as glucose-6-phosphate dehydrogenase, rather than the activation of lipolysis enzymes. Additionally, leucine adminstration resulted in improved glucose metabolism.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.193-200
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• 2006

We investigated the effect of moisturizing and anti-oxidation of Astragalus membranaceus (Astragali Radix) root extract with respective to growing districts and extract methods for the purpose of development of cosmetic ingredients. Astragalii Radix was collected in Jecheon, Jeongseon, Taebaek, and Yeongju in Korea and China as growing districts. Formononetin was determinated by HPLC method as one of the various active agents in Astragalus membranaceus root extract. The 75% ethanol extract demonstrated to be more effective than $H_2O$-extracted one for a scavenging activities to DPPH radicals and reactive oxygens. The 75% ethanol extract showed $IC_{50}$ (50% scavenging concentration) of 2.162 mg/mL and 2.981 mg/mL in case of free radical scavenging activity test and reactive oxygen scavenging activity test, respectively Especially, free radical scavenging activity of isoflavonoids isolated from ethylacetate fraction was similar to scavenging activity of genistein. Astragalus membranaceus root extract of Jecheon district by sonicating extraction method was more effective in skin hydration compared with others.