• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.1
• /
• pp.78-83
• /
• 2011

The flower of Chrysanthemum morifolium Ramat. with antioxidant, anticancer, and anti-inflammatory functions has been a widely used traditional herb as a healthy beverage and medicine. The aim of the present study was to investigate a herb tea consisting of C. morifolium Ramat., Corni fructus and Schizandra chinensis Baillon for its hepatoprotective activity against $CCl_4$-induced toxicity in freshly isolated rat hepatocytes and antigenotoxic effect against oxidative stress induced DNA damage in human leukocytes. Three different compositions of the herb tea (Mix I, II, and III) were prepared by extracting with water at $90^{\circ}C$. Freshly isolated rat hepatocytes were exposed to $CCl_4$ along with/without various concentrations of each tea. Protection of rat primary cells against $CCl_4$-induced damage was determined by the MTT assay. The significant antihepatotoxic effect of the tea was shown in Mix I and II. The increased transaminase (AST and/or ALT) release in media of $CCl_4$ treated hepatocytes was significantly lowered by all the teas tested. The effect of the tea on DNA damage in human leukocytes was evaluated by Comet assay. All teas showed a protective effect against $H_2O_2$-induced DNA damage. From these results, it is assumed that herb tea based on C. morifolium Ramat., Corni fructus and Schizandra chinensis Baillon exerted antihepatotoxic and antigenotoxic effects.

• Journal of Food Hygiene and Safety
• /
• v.13 no.4
• /
• pp.370-376
• /
• 1998

The extraction yield of MeOH extract of green teas, oolong tea and black tea were 3 to 5, 4 to 5, and 5 to 7 fold higher than those of EtOH and EtAC extract, respectively. The amount of total catechins of EtAC extract of the black tea, and of the green teas and oolong tea were three- and two-fold higher than that of EtOH or MeOH extract of the corresponding teas, respectively. The antioxidative activities of EtOH, MeOH and EtAc extract were considerably higher than that of BHT and $dl-{\alpha}-tocopherol$ at 200 ppm level. The antioxidative activities of EtOH and MeOH extract at 200 and 500 ppm level, and of EtAc extract at 200 ppm level varied depending on the type of tea as follows : green tea I > green tea II > green tea III > oo-long tea> black tea. The antioxidative activity increased as the content of EGC increased. But the antioxidative activity of MeOH extract at 1000 ppm level, and of EtAc extract at 500 and 1000 ppm level were not affected by the content of EGC and EGCG.

• Korean Journal of Organic Agriculture
• /
• v.26 no.4
• /
• pp.707-717
• /
• 2018

The acaricidal activity of extracts of Gleditsia japonica var. koraiensis, Camellia sinensis, Cinnamomum cassia, Lantana camara and their mixtures against the tea red spider mite, Tetranychus kanzawai was evaluated. Treatments with mixtures 3 and 1 were effective against the adult females of T. kanzawai and yielded 82.0% and 77.3% adulticidal activities at 7 days after treatment, respectively. Treatment with mixture 2 revealed 68.0% adulticidal activity. Generally, the acaricidal activity of the single treatment of each plant extract was lower than the mixtures. The adult females of T. kanzawai treated with mixtures 3 and 1 produced only 24.0~29.6% as many eggs as control females did. The residue of the plant extracts tested had low adulticidal activity (16.7~31.3% at 7 days after treatment). All the plant extracts tested exhibited no remarkable toxic effect to the eggs of T. kanzawai. Treatments of mixtures 3 and 1 were effective against nymphs of T. kanzawai and led to emergence rates of 16.7 and 22.0%, respectively. These results suggest that mixtures 3 and 1 might be used for the control of T. kanzawai in tea fields.

• Food Science of Animal Resources
• /
• v.32 no.5
• /
• pp.652-658
• /
• 2012

This study was carried out to identify the ACE (Angiotensin converting enzyme) inhibitory activity of casein hydrolysates for development of anti-hypertensive hydrolysates. Sodium caseinate was treated with six kinds of commercial proteases such as Flavourzyme, Protamex, Neutrase 1.5, Alcalase, Protease M, and Protease S for 8 h individually, and was then treated with the enzyme combination for 4 h at $45^{\circ}C$. The hydrolysate which had the highest ACE inhibitory effect was then hydrolysed successively with three digestive enzymes: pepsin, trypsin, and ${\alpha}$-chymotrypsin, at $37^{\circ}C$ for 4 h under conditions mimicking those of the gastrointestinal tract. UF (ultra filtration) treatment was applied to one of the secondary hydrolysates to determine ACE inhibitory activity. When sodium caseinate was hydrolysed by commercial proteases, the degree of hydrolysis (DH) showed 2.54 to 4.25% and after secondary hydrolysis, DH showed 4.30 to 5.22%. ACE inhibitory activity and $IC_{50}$ values decreased, and inhibition rates increased during hydrolysis. Protamex treatment showed the lowest $IC_{50}$ value ($516{\mu}g/mL$) and Flavourzyme hydrolysate showed the highest $IC_{50}$value ($866{\mu}g/mL$). As the first hydrolysate was treated with Flavourzyme, the ACE inhibitory activity increased. Neutrase hydrolysate had the highest activity with an $IC_{50}$ value ($282{\mu}g/mL$). When Neutrase plus Flavourzyme treatment was hydrolyzed by digestive enzymes, the $IC_{50}$ value ($597{\mu}g/mL$) was decreased statistically (p<0.05). As Neutrase plus Flavourzyme hydrolysate is treated by UF with MW cut-off 10,000, permeate showed $273{\mu}g/mL$ of $IC_{50}$ value, showed no difference, but retentate which has over MW 10,000 showed statistically different $IC_{50}$ value, $635{\mu}g/mL$ (p<0.05).

• Journal of Animal Science and Technology
• /
• v.48 no.6
• /
• pp.767-776
• /
• 2006

Corresponding author:Deukhwan Lee, Department of Animal Life Resources, Hankyong National Univ. Seokjeong-dong Anseong-si Gyeonggi-do, Rep. of Korea 456-749Tel: 031-670-5091, Fax: 031-676-5091, E-mail : dhlee@hknu.ac.krGeneral performance with including environmental and management effects on linear type traits in Holstein cows were investigated. 115,646 valid records measured from cows over 1 yrs of age by Korean Animal Improvement Association from 2000 to 2004 were used for this study. Farm, appraisal year-month, appraisal person should affect linear type and scoring traits. Most of type traits and scoring traits would be significantly affected by parity and lactation stage after absorbing farm-appraisal year-month-person effects. Otherwise, some traits such as traits related to udder would be affected by registration criteria. However, interval of appraisal time and milking time would not affect these traits. The scores related to udder, teat placement and foot angle would be positively related to parity. Final score would be optimized at cows of 2nd and 3rd parities. Dairy form, front teat placement, rear udder height, rear udder width and final score would show similar to pattern of lactation curve at lactation stage. Dairy capacity composite index would also show similar to lactation curve. This result would be indicated that more concise standardizing system for linear type scoring rules would be needed. Furthermore, correcting system for parity and lactation stage would be needed because this factor should affect physiological status, specially, udder status.

• Journal of Energy Engineering
• /
• v.24 no.2
• /
• pp.129-143
• /
• 2015

Increasing concerns on climate change and energy security accelerated policies to reduce green-house gas emission, especially from the transportation sector. Electric vehicle (EV) has been on the spotlight to deal with such environmental issue and V2G (Vehicle-to-Grid) technology began to draw attentions as an alternative to reduce ownership costs while contributing to an efficient and decentralized power grid. This study conducts a scenario analysis on total cost of ownership of EV under V2G scheme and compare with non-V2G EV and Internal Combustion Engine (ICE) vehicle. As result, V2G service is expected to provide an annual average profit of $210 to EV users willing to reverse flow its residual power in the battery. The profit from V2G service leaves a margin of $4,530 over operational lifetime, compared with $2,420 cost of charge for non-V2G EV. In summary, total cost of ownership of V2G-capable EV was 6.2% less than non-V2G EV and 10.2% higher than ICE vehicle. The results confirm a comparative economic advantage of operating EV under V2G scheme. Increased number of EVs with V2G service has shown to provide positive effects to power industry for valley filling in load distribution, thus, favorably increasing the overall economic feasibility.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.104-105
• /
• 2002

Hyper-Rayleigh scattering(HRS)방법을 이용하여 쌍극자와 새로이 합성된 팔중극자들의 1차 초분극율 $\beta$를 측정하였다. External reference 법을 이용하였고, reference 물질로는 잘 알려져 있는 쌍극자인 PNA를 이용하여 Disperse Red 1과 팔중극자들의 1차 초분극율 $\beta$의 값을 구하였다. 또한 HRS 의 세기뿐만 아니라 이들 물질의 two-photon induced fluorescence 스펙트럼을 측정하였다. 1차 초분극율 $\beta$값은, 먼저 시료로부터 scattering 된 신호를 파장변화에 따른 스펙트럼으로 측정하여 two-photon induced fluorescence를 뺀 순수한 HRS 신호만을 이용하고, 실험에 사용된 물질들은 532nm에서 흡수가 있어 second harmonic generation 신호가 시료에 의해 흡수가 되므로 흡수효과를 식 $I_{2{\omega}}$(obs)= $I_{2{\omega}}$(true) $e^{-{\sigma}lN}$ ---(1)를 이용하여 흡수에 의한 신호의 감소 효과를 보정하여 값을 구했다. (중략)

• 한국노년학
• /
• v.34 no.2
• /
• pp.315-331
• /
• 2014

The goal of this study was to examine the association between employment and depressive symptoms among older adults in Korea, including analysis of potential gender differences. Using a sample of Korean adults aged 60 years or older from the 2008(Time 2) and 2010(Time 3) national longitudinal survey data from the Korean Longitudinal Study of Ageing, we regressed measures of depressive symptoms at Time 3 on employment at Time 2 (and employment both at Time 2 and Time 3), controlling for Time 2 depressive symptoms, subjective physical health, and sociodemographic variables as well. First, there was no evidence that older adults with a job at Time 2 had significantly lower levels of depressive symptoms at Time 3 compared to their counterparts. However, multi-group analyses showed that the effect of employment at Time 2 on depression at Time 3 differed by gender. For older men, employment predicted better mental health over time. However, this was not the case for older women. As such work role provided benefits only for older men. Second, older adults with a job at both Time 2 and Time 3 reported significantly lower levels of depressive symptoms at Time 3 than older adults who did not have a job either at Time 2 or Time 3. However, only older men who were employed at both Time 2 and Time 3 reported significantly less depression than their counterparts. These findings suggest that the mental health effects of employment are contingent on gender.

• Journal of Life Science
• /
• v.2 no.4
• /
• pp.240-247
• /
• 1992

차의 풍미의 차이는 차잎 자체가 가자고 있는 화학성분 조성의 차이와 가공방법의 차이에 기인하고, 차잎의 화학성분은 차나무의 훔종, 토질, 기후, 재배기술과 시비 등에도 영향을 받는다. 차의 특유한 맛의 주성분은 주로 카테킨과 아미노산류이다. 단맛과 감칠맛은 주로 아미노산 때문이지만 당류도 어느 정도 기여한다. 카테킨류에 의한 최근의 연구결과를 보면 노화를 방지하는 1)항산화 작용 2) 항종양, 발암 억제작용 3) 콜레스테롤 량의 조정 4)고혈압과 혈당 강하작용 5)항균작용과 해독작용이 있다.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.344_346
• /
• 2009

본 논문에서는 전력계통에서 고장발생시 자속의 변화를 통한 magnetic switching을 이용한 전류제한기를 제안하였다. 구조는 자속이 흐를 수 있는 철심과 회로에 연결되어 있는 1차권선, 철심과 1차권선 사이에 위차한 1차권선과 반대방향으로 감겨져 있는 2차권선 및 2차권선 하부에 이동이 가능한 동판의 2차권선 secondary로 구성되어 있다. 정상상태에서는 철심내에 1차권선과 2차권선에 의해 발생된 자속이 서로 상쇄되어 두 권선에 유기되는 전압은 0이지만 고장이 발생하여 2차 권선의 스위치를 open하고 2차권선 secondary를 철심밖으로 쳐 내면 그동안 상쇄되었던 자속이 철심을 통하여 흐르게 되고 이에 따라 1차권선에 유기된 전압은 회로의 전류를 제한하게 되므로 차단기를 용이하게 동작시킬 수 있는 구조이다. 실험을 통하여 전류제한기 동작 전 후의 전류제한 효과를 분석하였으며 이를 통해 본 논문에서 제안하는 시스템은 차단기에 가해지는 아크충격을 완화하여 설비의 수명을 연장하고 적은 용량의 차단기 사용이 가능하므로 설비투자예산 절감 및 모든 차단기 사용분야에 활용될 수 있는 장점을 가지고 있음을 확인하였다.