• Journal of Nutrition and Health
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• 제44권6호
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• pp.507-517
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• 2011

The purpose of this study was to investigate the effects of gender on the thermic effect of food and substrate oxidation rate during 5 hours after a mixed meal. Twenty healthy college students (10 males and 10 females) aged 20-26 years participated in this study. The energy contents of the experimental diets were 775 kcal and 627 kcal for males and females respectively, which were 30% of individual energy requirements and were composed of 65/15/20% as the proportion of carbohydrate/protein/fat. Resting and postprandial energy expenditure and substrate oxidation rates were measured with indirect calorimetry in the fasting state and every 30 min for 5 hours after meal consumption. Thermic effects of food expressed as ${\Delta}AUC$ and TEF% were not significantly different between males and females. However, TEF% adjusted for body weight and fat-free mass in males (0.095% and 0.120%) were significantly lower than those in females (0.152% and 0.213%)(p < 0.05). The total amount of carbohydrate oxidized was significantly lower in males than that in females (58.6 vs. 86.6 mg/kcal energy intake/5 h, p < 0.05). In contrast, the total amount of fat oxidized was significantly higher in males than that in females after the meal (32.9 vs. 17.2 mg/kcal energy intake/5 h, p < 0.01). These results indicate that gender affects the thermic effects of food and the substrate oxidation rate after a meal. The results show that males use relatively less carbohydrate and more fat as an energy source after a meal than that of females.

• 분석과학
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• 제13권2호
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• pp.234-240
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• 2000

수질계의 부식산을 화학적 산화처리하기 위한 방법의 하나로 광산화공정을 도입하여 부식산의 특성 변화를 조사하였다. 광산화공정은 UV단독, UV/$TiO_2$ 및 UV/$H_2O_2$ 시스템을 실험하였다. UV 단독 조사시 TOC 제거율은 pH 7-9에서 가장 높았으며, 흡광도는 강알카리성 영역에서 감소율이 향상된 결과를 보였다. 각 시스템별로 처리도를 보면, UV/$TiO_2$ 시스템의 경우 $TiO_2$ 의 농도가 50ppm 일때 TOC 제거와 흡광도 감소의 효율이 높았으며 50ppm 이상을 투입해도 처리율에 변화가 없었다. UV/$H_2O_2$ 시스템에서는 과산화수소의 농도가 20mM이 최적의 주입농도로 조사되었으며, 그 이상 투입할 경우 TOC와 흡광도의 처리율이 저하되었다. 탄산이온을 첨가할 경우, TOC 제거율 및 UV 흡광도의 감소율 모두 감소하며, TOC 제거율이 흡광도 감소율에 비해 상대적으로 더 크게 나타났다.

• 대한지역사회영양학회지
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• 제9권4호
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• pp.536-544
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• 2004

To evaluate the antioxidative effect of maengjong-juk (Phyllostachys pubescens) extract coated rice in vivo system, maengjong-juk extract coated rice diets were fed to C57BL/6 mice for 16 weeks. Plasma total antioxidative capacity, hepatic lipid peroxidation, protein oxidation, activities of antioxidative enzymes and total glutathione content were measured. Plasma total antioxidative capacity was elevated significantly in maengjong-juk extract diets supplemented group in a dose dependant manner. Hepatic TBARS contents were significantly decreased in maengjong-juk extract diets supplemented group compared to high cholesterol group. Maengjong-juk extract coated rice diets suppressed the protein oxidation significantly in liver. Activities of hepatic antioxidative enzymes such as total SOD, CuㆍZn-SOD, Mn-SOD, GSH-Px and catalase activities of maengjong-juk extract coated rice diets were significantly higher than those of high cholesterol diet. Total hepatic glutathione content was significantly increased by maengjong-juk extract coated rice diets administration. According to this study, numerous antioxidative materials and phytochemicals containing in maengjong-juk extracts appear to protect antioxidative systems in C57BL/6 mice fed bamboo extract coated rice diet. (Korean J Community Nutrition 9(4): 536∼544, 2004)

• 한국지하수토양환경학회지:지하수토양환경
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• 제6권3호
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• pp.13-20
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• 2001

본 연구에서는 고농도 유류오염토양 처리를 위해 ${H_2}{O_2}$/$Fe^0 시스템을 이용한 Fenton-like oxidation을 제시하였다. 주요 반응조건인 초기 PH, $Fe^0 및 ${H_2}{O_2}$ 주입량과 초기 오염농도를 변화시켜가며 본 산화처리 시스템의 반응특성을 회분식 실험을 통하여 알아보았다. 유류 오염물은 디젤을 사용하였으며 오염농도는 가스 크로마토그래피를 사용하여 TPH (Total Petroleum Hydrocarbon)로 나타내었다. 제거효율을 보면 적정 ${H_2}{O_2}$/$Fe^0 주입조건인 10% ${H_2}{O_2}$+ 20% Fe$^{0}$ 에서 반응시간 24이내에 약 65% 이상의 제거율(초기 TPH 농도 : 10,000mg/kg)을 나타내었으며, 초기 pH조건은 높은 제거효과를 얻기 위해서 3~4범위이내가 적정함을 알 수 있었다. 기존의 과산화수소의 분해촉매로 사용하는 철 염($FeSO_4)과의 비교실험에서는 $Fe^0를 촉매로 사용하였을 때 유류오염토양의 화학적 산화 처리가 처리효율과 경제성에서 더 효과적임을 알 수 있었고, 특히 고농도 오염토양 처리에서 더 유리한 것으로 나타났다.

• 한국환경농학회지
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• 제33권4호
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• pp.306-313
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• 2014

BACKGROUND: Forest soils contain microbes capable of consuming atmospheric methane ($CH_4$), an amount matching the annual increase in $CH_4$ concentration in the atmosphere. However, the effect of plant residue production by different forest structure on $CH_4$ oxidation is not studied in Korea. The objective of this study was to evaluate the effect of Korean alpine soils having different forestation structure on $CH_4$ uptake rates. METHODS AND RESULTS: the $CH_4$ flux was measured at three sites dominated with pine, chestnut and oak trees in southern Korea. The $CH_4$ uptake potentials were evaluated by a closed chamber method for a year. The $CH_4$ uptake rate was the highest in the pine tree soil ($1.05mg/m^2/day$) and then followed by oak ($0.930mg/m^2/day$) and chestnut trees ($0.497mg/m^2/day$). The $CH_4$ uptake rates were highly correlated to soil organic matter and moisture contents, and total microbial and methanotrophs activities. Different with the general concent, there was no any correlation between $CH_4$ oxidation rates, and soil temperature and labile carbon concentrations, irrespective with tree species. CONCLUSION: Conclusively, the methane oxidation rate was correlated in positive manner with organic matter, abundance of methanotrophs. Methane oxidation was different among tree species. This results could be used to estimate methane oxidation rate in forest of Korea after complementing information about statistical data and methane oxidation of other site.

• 한국축산식품학회지
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• 제36권1호
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• pp.44-50
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• 2016

This study was conducted to observe the association between antioxidant enzyme activity, free iron content and lipid oxidation of Korean native chicken (KNC) meat during refrigerated storage. Four lines of KNC (Yeonsan ogye, Hyunin black, Hoengseong yakdak and Hwangbong) were raised under similar conditions. A total of 16 roosters were randomly sampled and slaughtered at the age of 12 mon. The breast and thigh meats were stored aerobically for 10 d at 4℃. Although thigh meat had higher antioxidant enzyme activity, it was more susceptible to lipid oxidation and released more iron during storage than breast meat. Aerobic refrigerated storage for 10 d significantly decreased the activity of antioxidant enzymes and increased the amount of free iron and malondialdehyde. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were negatively correlated with lipid oxidation, whereas that of catalase was not. The amount of free iron was positively associated with lipid oxidation. We concluded that chicken line did not affect strongly on antioxidant enzyme activity and lipid oxidation in breast meat of KNC. However, the thigh meat of Hwangbong and Hyunin black had higher SOD and GSH-Px activity, respectively, and lower malondialdehyde contents than that of other chickens. SOD, GSH-Px and free iron play significant roles in meat lipid oxidation during refrigerated storage.

• 대한기계학회논문집B
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• 제24권5호
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• pp.660-667
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• 2000

In order to investigate the exhaust structure and secondary oxidation of unburned hydrocarbon (HC) in the exhaust port, concentrations of individual HC species were measured in exhaust process, the degree of oxidation were obtained. Using a solenoid-driven fast sampling system on single-cylinder research engine fueled with 94% propane, the profiles of unburned hydrocarbons (HCs) and non-fuel HCs with a propane fueled engine were obtained from several locations in the exhaust port during the exhaust process. The sampled gases were analyzed using a gas chromatography of HC species with 4 or lesser carbon atoms. The change of total HC concentration and HC fractions of major components through the exhaust port were discussed. The results showed that non-uniform distribution of HC concentration existed around the exhaust valve and changed with time, and that the exhaust gas exhibited nearly uniform concentration profile at port exit, which was due to mixing and oxidation. Also it could be known that bulk gas with relatively high HC concentration came out through the bottom of the exhaust valve. To estimate the mass-based degree of HC oxidation in the exhaust port from measured HC concentrations, a 3-zone diagnostic cycle simulation and plug flow modeling were used. The degree of oxidation ranged between 26 % and 36 % corresponding to the engine operation conditions.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.87-90
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• 1998

Hemolymph is oxidized and darkens visibly during the collection from silkworm due to the activity of tyrosinase in it. Toxic quinones are produced by the oxidation and consequently inhibit the cell growth. Heat treatment can be used to prevent the oxidation ; however, the oxidation may occur during the collection of hemolymph before it is heat-treated. It makes the hemolymph collection difficult especially on a large-scale preparation. Hemolymphs collected from 257 different strains of silkworms were examined to select the slowly oxidized hemolymphs. Hemolymphs collected from mutant strains such as Lemone, TBO, Cre, Y4, and wEb showed relatively slow color changes. Oxidation rates of the hemolymphs were measured by the absorbance change using a spectrophotometer. The hemolymph of wEb showed the slowest oxidation. The absorbance of this mutant hemolymph reached the saturation value at 20$^{\circ}C$ in 450 min, whereas the total oxidation time of the wild-type (Baekokjam) hemolymph at the same temperature was 120 min. We tested if this mutant hemolymph is useful as a medium supplement for insect cell culture. Cell growth rate and final cell concentration in the medium supplemented with the wEb hemolymph were almost same as those in the medium supplemented with the wild-type hemolymph. Hemolymph is collected on a small scale by clipping the abdominal leg; however, this method is not appropriate fro large scale preparation. Centrifugation after chopping the silkworm hemolymph by a blending mixer is a more appropriate procedure for large scale collection. Slowly oxidized wEb hemolymph resulted in higher cell concentration than the wild-type hemolymph when hemolymph was collected by the large scale preparation method.

• 한국식품영양과학회지
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• 제28권5호
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• pp.984-989
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• 1999

This study was carried out to investigate the effects of ethanol extracts on lipid oxidation of oil emulsion. The results are as follows; The scavenging ability of plant extracts for hydroxyl radical was found, and plant extracts played an important role as a strong chelating agents to bind iron if Fe2+ ion exists in oil emulsion. Pinus densiflora(PD), Lithospermum erythrorhizon(LE) and PD＋LE acted as strong chelating agents to bind iron to reduce lipid oxidation in oil emulsion. The content of Fe2+ ion in ethanol extracts from LE and PD＋LE were significantly higher(p<0.05) than that of ethanol extracts from PD. The content of total iron has same tendency. The ascorbic acid content of PD(16.36ppm) was slightly higher than those of LE(13.08ppm). Electron donating ability of PD was significantly higher(p<0.05) than those of LE. However, the superoxide(SOD) like ability of LE showed a little higher than those of LE and PD＋LE, which means the strong antioxidant activity of LE. The nitrite scavenging effects were dependent on pH value, however, they decreased as pH value increased. Especially, they almost didn't show the nitrite scavenging effect in pH 6.0. In conclusion, the PD and LE extracts may be used as natural antioxidant sources to reduce lipid oxidation in oil emulsion.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.179-183
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• 2002

Lycopene as a natural antioxidant may provide protection against a broad range of epithelial cancers and chronic diseases. Lycopene concentrate extracted from tomatoes can be used as functional food. Lycopene would undergo degradation via isomerization and oxidation under different processing conditions, which impact its bioactivity and reduce the fuuctionality for health benefits. Heat and light induce lycopene oxidation and isomerization of all-trans form to cis form. The effects of thermal treatment and light irradiation on the stability of lycopene were determined. Results have shown that lycopene stability depends on the extent of oxidation and isomerization. Cir-isomers are less stable than trans-isomers. The level of cis-isomers increased as treatment time increased but only for a short period during the beginning of the treatment. The major effect of thermal treatment and light irradiation was a significant decrease in the total lycopene content. A true assessment of health benefits of lycopene concentrate depends on the lycopene content and the composition of all trans-isomers and cia-isomers.