• Journal of Applied Biological Chemistry
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• 제54권3호
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• pp.197-205
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• 2011

This study was carried out to investigate the dietary effects of Monascus pilosus mycelial extract on obesity in high-fat with cholesterol-induced obese rat models. It was observed that M. pilosus mycelial extract contains $25.85{\pm}1.98mg%$ of total monacolin K without citrinin by highperformance liquid chromatography (HPLC). The rats were randomly divided into 2 groups; normal control and a high-fat with cholesterol diet group. The high-fat with cholesterol diet group was fed a 5L79 diet with an added 15% lard and 1% cholesterol supplemented diet for 3 weeks for induction of obesity. After induction, obesity was confirmed by checking obesity indexes, the animals were divided into 4 groups (n=5); first, the normal control (NC), and then taken from the obese model of rats, a high-fat with cholesterol diet obesity control group (HF), 0.5% M. pilosus mycelial extract supplemented high-fat with cholesterol diet group (MPMs), 2% conjugated linoleic acid supplemented high-fat with cholesterol diet group (CLA) for 7 weeks. Body weight gains, obesity indexes, and body fat contents in the experimental groups (MPMs and CLA) were decreased compared with HF group. Feed Efficiency Ratio (FER) in MPMs was significantly lower than that of HF without change of feed intake. These results suggested that the anti-obesity effects of the M. pilosus mycelial extracts (MPMs) could prevent obesity induced by high-fat with cholesterol diet possibly via inhibition of lipid absorption.

• Toxicological Research
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• 제31권2호
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• pp.97-104
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• 2015

The skin exposure to solar irradiation and photoreactive xenobiotics may produce abnormal skin reaction, phototoxicity. Phototoxicity is an acute light-induced response, which occurs when photoreacive chemicals are activated by solar lights and transformed into products cytotoxic against the skin cells. Multifarious symptoms of phototoxicity are identified, skin irritation, erythema, pruritis, and edema that are similar to those of the exaggerated sunburn. Diverse organic chemicals, especially drugs, are known to induce phototoxicity, which is probably from the common possession of UV-absorbing benzene or heterocyclic rings in their molecular structures. Both UVB (290~320 nm) and UVA (320~400 nm) are responsible for the manifestation of phototoxicity. Absorption of photons and absorbed energy (hv) by photoactive chemicals results in molecular changes or generates reactive oxygen species and depending on the way how endogenous molecules are affected by phototoxicants, mechanisms of phototoxcity is categorized into two modes of action: Direct when unstable species from excited state directly react with the endogenous molecules, and indirect when endogeneous molecules react with secondary photoproducts. In order to identify phototoxic potential of a chemical, various test methods have been introduced. Focus is given to animal alternative test methods, i.e., in vitro, and in chemico assays as well as in vivo. 3T3 neutral red uptake assay, erythrocyte photohemolysis test, and phototoxicity test using human 3-dimensional (3D) epidermis model are examples of in vitro assays. In chemico methods evaluate the generation of reactive oxygen species or DNA strand break activity employing plasmid for chemicals, or drugs with phototoxic potential.

• 한국진공학회지
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• 제17권5호
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• pp.426-434
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• 2008

고밀도 유도결합 플라즈마 장치의 $SiH_4/O_2/Ar$방전에 대한 공간 평균 시뮬레이터를 제작하였다. 제작된 시뮬레이터는 $SiH_4/O_2/Ar$ 플라즈마 방전에서 발생되는 전자, 양이온, 음이온, 중성종, 그리고 활성종들에 대해 공간 평균한 유체 방정식을 기반으로 하고 있으며, 전자가열 모델은 anomalous skin effect를 고려한 파워 흡수 모델을 적용하여 전자가 흡수하는 고주파 파워량을 결정하였다. 완성된 시뮬레이터에서 RF-파워와 압력 변화에 대한 하전입자, 중성종, 활성종들의 밀도 변화 및 전자 온도 의존성을 계산하였다.

• 한국식품영양학회지
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• 제25권2호
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• pp.246-252
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• 2012

After a mixed carbohydrate diet, inhibition of ${\alpha}$-amylase and ${\alpha}$-glucosidase involved in the digestion and absorption of carbohydrates can significantly decrease the postprandial increase of blood glucose level. In the course of screening these useful enzyme inhibitors, we selected five kinds of bean, using an in-vitro enzyme inhibition assay method. To evaluate the effect of germination process on the functionality of the bean, we investigated the inhibitory activities of the water extracts of non-germinated bean and germinated bean against ${\alpha}$-amylase and ${\alpha}$-glucosidase, relevant to postprandial hyperglycemia. We also investigated the oxygen radical absorbance capacity(ORAC), total phenolics content, and postprandial blood glucose lowering effect in rats(Sprague-Dawley rat model). Most germinated beans showed significantly higher ${\alpha}$-glucosidase inhibitory activity, compared with non-germinated beans. Among germinated beans, Glycine max had the highest ${\alpha}$-glucosidase inhibitory activity(53.3%). The water extract of germinated Phaseolus vulgaris L. had the highest ${\alpha}$-amylase inhibitory activity(95.1%), followed by Glycine max(58.7%), and Glycine max L. Merr(54.1%). Furthermore, the five germinated beans also showed high antioxidant activities in ORAC assay. Results suggested that the germination process may improve and enhance the anti-hyperglycemia potential and antioxidant activity of the bean.

• 한국건축시공학회지
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• 제11권4호
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• pp.371-378
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• 2011

콘크리트는 다공질로서 수분이 접하게 되면 시간경과에 따라 흡수가 일어난다. 다양한 배합의 콘크리트에서 어느 정도 수분 흡수가 빨리 일어나는가는 흡수수분 확산계수 산출을 통하여 가능하며, 본 연구에서는 길이가 다른 시험체의 질량 경시변화를 통하여 깊이별 흡수 수분량을 산출하였다. 흡수 수분 확산계수는 시간과 깊이의 함수로 이뤄진 볼츠만 변수를 사용하여 실험값과의 회귀분석을 통하여 구하였으며, 그 정확도는 비선형 유한요소 과도해석을 통하여 검증하였다.

• 천문학회보
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• 제36권2호
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• pp.88.2-88.2
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• 2011

Fast Imaging Solar Spectrograph (FISS) is an instrument developed by Seoul National University and Korea Astronomy and Space Science Institute and installed at the 1.6 meter New Solar Telescope of Big Bear Solar Observatory. Using this instrument, we observed solar filaments and analyzed the data focusing on determining the temperature and non-thermal velocity. We inferred the Doppler absorption widths of $H{\alpha}$ and Ca II 8542$\bar{A}$ lines from the line profiles using the cloud model. From these values, we separately determined temperature and non-thermal velocity. Our first result came from a solar filament observed on 2010 July 29th. Temperature inside a small selected region of this ranges from 4500K to 12000K and non-thermal velocity, from 3.5km/s to 7km/s. We also found temperature varied a lot with time. For example temperature at a fixed point varied from 8000K to 18000K for 40 minutes, displaying an oscillating pattern with a period of about 8 minutes and amplitude of about 2000K. We will also present new results from filaments observed in 2011 summer.

• Korean Chemical Engineering Research
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• 제55권1호
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• pp.86-92
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• 2017

석탄 화력발전 연소 배가스에 포함된 이산화탄소를 염수의 전기분해를 통해 얻어진 가성소다와 반응시켜 중탄산나트륨, 염소, 수소 등을 생산하는 공정에 대하여 실험과 전산모사를 병행하였다. Bench 규모 공정을 디자인하여 가성소다에 의한 이산화탄소 전환 공정에 대하여 실험하였고 같은 공정을 공정 모델링을 통해 전산모사 하였다. 실험결과와 전산모사 결과의 비교를 통해 모델의 신뢰성을 확인하였고, 상용급 공정에 대한 모델링을 수행하였다. 상용급 공정에 대한 열 및 물질수지를 계산하였고 반응기내 온도분포와 $CO_2$ 흡수율을 도출하였다. 본 연구를 통해 온실가스 저감뿐만 아니라 $CO_2$ 전환을 통한 경제성까지 갖춘 본 공정에 대한 기술 신뢰성을 확보할 수 있을 것이다.

• Safety and Health at Work
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• 제3권4호
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• pp.268-277
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• 2012

Objectives: 1) To determine mercury levels in urine samples from garbage workers in Southern Thailand, and 2) to describe the association between work characteristics, work positions, behavioral factors, and acute symptoms; and levels of mercury in urine samples. Methods: A case-control study was conducted by interviewing 60 workers in 5 hazardous-waste-management factories, and 60 matched non-exposed persons living in the same area of Southern Thailand. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer. Results: The hazardous-waste workers' urinary mercury levels (10.07 ${\mu}g/g$ creatinine) were significantly higher than the control group (1.33 ${\mu}g/g$ creatinine) (p < 0.001). Work position, duration of work, personal protective equipment (PPE), and personal hygiene, were significantly associated with urinary mercury level (p < 0.001). The workers developed acute symptoms - of head-aches, nausea, chest tightness, fatigue, and loss of consciousness at least once a week - and those who developed symptoms had significantly higher urinary mercury levels than those who did not, at p < 0.05. A multiple regression model was constructed. Significant predictors of urinary mercury levels included hours worked per day, days worked per week, duration of work (years), work position, use of PPE (mask, trousers, and gloves), and personal hygiene behavior (ate snacks or drank water at work, washed hands before lunch, and washed hands after work). Conclusion: Changing garbage workers' hygiene habits can reduce urinary mercury levels. Personal hygiene is important, and should be stressed in education programs. Employers should institute engineering controls to reduce urinary mercury levels among garbage workers.

• 한국식품영양과학회지
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• 제32권8호
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• pp.1370-1376
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• 2003

식이성 고지혈증 model 실험동물을 사용하여 해조 음료를 투여하여 지질 산화와 관련된 효소 변화 및 혈액응고에 미치는 영향을 시험하였다. 혈액의 lipid peroxide 함량과 혈중 hydroxy radical 생성이 식이성 고지혈증의 유도로 증가되었으며, 혈중 superoxide dismutase의 활성은 오히려 감소되던 것이 해조 음료의 투여로 조절되었다. 식이성 고지혈증을 유도한 흰쥐에서 감소되었던 bleeding time과 plasma clotting time이 해조 음료의 투여로 다소 증가하였고, 증가하였던 tissue factor의 활성은 현저히 감소되었다 동물 소화장관에 대한 운동성 시험에서는 해조 음료의 투여로 장관 운동이 증가되는 것을 확인하였다. 이러한 결과는 해조 음료나 해조 음료 소재에 다량 함유되어 있는 해조 올리고당이 기존의 해조 다당과 마찬가지로 혈관계 관련 질병의 예방에 유효한 기능을 할 수 있다는 것을 나타내며 향후로도 다양한 기능성 제품의 소재가 될 수 있을 것으로 여겨진다.

• 대한전자공학회논문지
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• 제21권5호
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• pp.90-99
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• 1984

양면에서 텅스텐 램프를 조사하는 실리콘 재결정시의 SOI(silicon-on-insulator) 다층구조에 대한 1차원적 온도 및 열원(열원)의 분포를 SOR(successive over-relaxation)방법을 이용하여 정상상태의 열방정식의 해로부터 구하였다. 열원의 분포는 광원의 스펙트럼, SOI sample 내부 계면에서의 다중반사, 광흡수 계수의 온도, 주파수 의존성 등을 고려하여 구하였으며, 열 방정식의 경계조건이 되는 wafer의 전면과 후면의 온도는 혹체복사 조건으로부터 구하였다. 내부계면에서는 전도열속(conduction heat flux)과 복사열속(radiation heat flux)에 의한 연속조건을 만족하도록 하였다. 본 문제에서의 온도분포와 열원의 분포는 상호간에 큰 영향을 주게 되므로, 두가지 변수가 일치되는 값을 보일 때까지 iteration을 계속하였다. Pyrometer을 이용하여 측정한 wafer 전면의 온도는 약1200°K이었고 이때의 simulation 결과는 1120°K 정도로 나타났다.