• 대한치과교정학회지
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• 제48권6호
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• pp.384-394
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• 2018

Objective: This study was performed to investigate an appropriate degree of prestretch for orthodontic synthetic elastomeric chains focusing on time-dependent viscoelastic properties. Methods: Orthodontic synthetic elastomeric chains of two brands were prestretched to 50, 100, 150, and 200% of the original length in one and three cycles, and the hysteresis areas of the obtained stress-strain curves were determined. Acrylic plates were employed to maintain constant strain during the experiment. A total of 180 samples were classified into nine groups according to brand, and their stresses and permanent deformations were measured immediately after prestretch (0 hour), after 1 hour and 24 hours, and after 1, 2, 3, 4, 5, 6, 7, and 8 weeks. The relationship between stress relaxation and permanent deformation was investigated for various degrees of prestretch, and the estimated stress resulting from tooth movement was calculated. Results: The degree of prestretch and the stress relaxation ratio exhibited a strong negative correlation, whereas no correlation was found between the degree of prestretch and the average normalized permanent strain. The maximal estimated stress was observed when prestretch was performed in three cycles to 200% of the original length. Conclusions: Although prestretch benefited residual stress, it did not exhibit negative effects such as permanent deformation. The maximal estimated stress was observed at the maximal prestretch, but the difference between prestretch and control groups decreased with time. In general, higher residual stresses were observed for product B than for product A, but this difference was not clinically significant.

• 사상체질의학회지
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• 제12권2호
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• pp.171-183
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• 2000

1. Back ground and purpose An experimental study has done to examine the effect of defense and cure gastric mucasal damage of Mokdan-pijihwang-tang. 2. Methods Mice had intragastric injected with MJ extract before indomethacin treatment which induces homorrhage infarct and erosion artificially. Degree of lipid peroxidation, general morphology, change of mucous cell, the distribution of PNA, ICAM and distribution of apoptotic cell were objected. (Abbreviation) MJ : Mokdanpijihwang-tang, PNA : Peanut Agglutinin, ICAM : Intercellular Adhesion Molecule 3 Results 1) The degree of lipid peroxidation in INDO-group had increased conspicuously than control group. But the degree of lipid peroxidation in MJ-group had decreased than INDO-group and these decline had probability. 2) After indomethacin treatment, hemorrhage infarct and erosion had increased in stomach body. But in MJ-group, the configuration is normal, except the group intragastric injected with MJ extract at hour 24 before indomethacin treatment. 3) Surface mucous cell and neck mucous had disappeared in INDO-group. But in MJ-group tormal distribution had shown like control group except the group intragastric injected with MJ extract at hour 24 before indomethacin treatment. 4) PNA positive reaction had not shown in INDO-group. But medium PNA positive reaction had shown In Mj-group. 5) ICAM positive reacted cell had shown in INDO-group. The decrease of ICAM positive cell were shown than INDO-group. 6) A number of apoptotic cell was distributed in hemorrhagic erosion. A few number of apoptotic cell was distributed in MJ-group except some surface mucous. 4. Conclusion These results suggest that MJ has an effect on cure of gastric mucosal damage.

• Journal of Chest Surgery
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• 제10권1호
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• pp.124-132
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• 1977

A experimental study of deep hypothermia for open heart surgery in 5 dogs was reviewed. Surface hypothermia in combination with limited cardiopulmonary bypass was employed. Circulatory dynamics were well maintained following cardiac arrest during one hour at $20^{\circ}C$. Some degree of acidosis usually developed after the arrest period but was gradually corrected during. rewarming Total circulatory occlusion could be maintained for at least one hour at $20^{\circ}C$ without evidence of cerebral damage in the dogs. Potassium in the serum after deep hypothermia was moderately decreased and it was the most severe change in the electrolyte. Free hemoglobin of serum was mild increased and it was one of advantages of combined hypothermia with limited cardiopulmonary bypass.

• 생물환경조절학회지
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• 제25권4호
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• pp.308-319
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• 2016

온실의 냉난방시스템 설계 기준에 적용하기 위한 외부기상조건을 설정하기 위하여 난방 설계용 외기온, 난방 degree-hour, 냉방 설계용 건구온도, 습구온도, 일사량을 분석하여 제시하였다. 우리나라 전 지역을 대상으로 현재 기상청에서 제공하는 기후평년값 기준인 1981~2010년까지 30년간의 매 시각 기상자료를 분석에 사용하였다. 표준기상데이터의 이용이 제한적이기 때문에 30년간의 전체 기상자료를 이용하여 설계용 기상조건을 구하고, 전체 자료기간의 평균값을 설계기준으로 제시하였다. TAC 방식으로 위험률 1, 2.5, 5%에 대한 설계용 기상자료를 분석하고, 설계기준에서 추천하고 있는 난방용은 위험률 1%, 냉방용은 위험률 2.5%의 기상조건 분포도를 제시하였다. 지역별, 위험률별 및 설정온도별로 최대난방부하, 기간난방부하 및 최대냉방부하의 변화를 고찰하였다. 제시된 각종 설계용 기상조건은 온실의 냉난방시스템 설계에 직접 이용할 수 있을 뿐만 아니라 냉난방 설비 보강이나 에너지 절감대책의 수립에 활용이 가능할 것으로 판단된다. 한편 기후변화로 인하여 최근 여름철 폭염이나 겨울철 이상고온 현상이 자주 발생하고 있으므로 주기적인 설계용 기상자료의 분석이 필요하고, 최소한 10년 주기로 설계기준을 개정할 필요가 있는 것으로 생각된다. 본 연구에서는 현재 기후평년값 기준인 1981~2010년까지의 기상자료를 분석하였으나 이 기준이 1991~2020년으로 바뀌는 2021년에는 즉시 이 기간의 기상자료를 분석하여 새로운 설계기준으로 제공해야 할 것으로 판단된다.

• 대한지역사회영양학회지
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• 제14권4호
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• pp.441-450
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• 2009

The prevalence of obesity in children has steadily risen during recent years in developed countries. Child obesity has become a major concern to health providers since it has grown to epidemic proportions over the past few decades. This study was conducted to investigate the biochemical status, dietary habits and life styles according to the obesity degree among obese children residing in the Gyungbuk area. The subjects were 148 elementary school students (boy 103, girl 45) and classified as mildly obese (n = 56), moderately obese (n = 61) and severely obese (n = 31) by the obesity index. The average body weight and height increased significantly according to the obesity degree (p < 0.05, p < 0.001). Serum cholesterol concentration came under the normal level in all groups. Serum AST activity increased according to the obesity degree but it was not significant. Serum ALT activity increased according to the obesity degree (p < 0.05). Dietary habit score was lower significantly according to the obesity degree (p < 0.01). Life style of the subjects was significantly different for the level of 'healthy state (p < 0.05)', 'body perception (p < 0.01)', 'watching TV and video (p < 0.05)', 'normal sleeping hour (p < 0.05)' and 'degree of stress (p < 0.05)' according to the obesity degree. A positive relationship between obesity index and blood pressure, ALT has been shown in the subjects. Obesity index and dietary habit scores were negatively associated. Therefore, these results suggest that a practical nutrition-exercise education program for the prevention of child obesity should be provided to elementary school children. (Korean J Community Nutrition 14(4) : 441${\sim}$450, 2009)

• The Korean Journal of Physiology
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• 제6권2호
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• pp.9-17
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• 1972

This experiment was carried out to investigate systematically how the aerobic metabolic capacity of renal tissue reduced by the effects of a period of induced ischemia. Aerobic metabolic studies were performed on homogenates of cortex and medulla of rabbits. Ischemia was induced by occluding the renal vein or renal artery of the left kidney for an hour. The right kidney used as a paired control. Aerobic metabolism was asesssed by measuring the oxygen consumption using the Warburg's manometric apparatus. The results are summarized as follows: 1. One hour of occlusive ischemia does not increase in the kidney weight in the renal arterial occlusion but increase in the renal venous occlusion. 2. Occlusion of either the renal vein or renal artery for an hour did not reduce to any significant degree the level of endogenous substrate in cortical homogenates as measured the rates of $0_2$ consumption. 3. A significant reduction in the rate of $C_2$ consumption was noted in the medullary homogenates of renal venous occluded kidneys while renal arterial occlusion had less of an effect. 4. The capaciy of homogenates for aerobic metabolism is not reduced by acute ischemia, because of the higher rate of oxygen consumption induced by exogenous glucose in renal vein occlusion. 5. The oxygen consumption of medullary homogenate more decreased to acute ischemia than cortical homogenates. The results of this investigation suggest that one hour circulatory stasis does not reduce major potential capacity of renal cortical tissue at the subcellular level to produce energy. In contrast, the aerobic metabolism of medullary tissue is reduced by renal ischemia. Further, both cortex and medulla appear to be more sensitive to ischemia induced by renal venous occlusion than by renal arterial occlusion.

• Journal of Nutrition and Health
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• 제32권8호
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• pp.957-966
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• 1999

Underreporting of dietary intake is common and might distort analysis and interpretation of dietary surveys. This study was designed to investigate the degree of underreporting and characterastics of under-reporting group in Korean college female students. Dietary survey of 1-day 24-hour recall method was conducted on 379 college students in Seoul and Chonan areas. Physical activity and life style were aquired from questionnnaires. Underreporting was defined as energy intake(EI) lower than 0.9BMR(based metabolic rate), since EI<0.98BMR is statistically judged as bias in 1-day 24 hour recall. BMR was calculated from Schofield's equation. Proportion of underreporting was 18.7% and it's not so different from one of American or European women. Intake of nutrients except vitamin A by underreporting group was lower than other groups(p<0.001). Proportions of subjects with nutrient intake level less than 75% of Korean RDA were more than 80% in protein, Ca, Fe, vitamin A, riboflavin, niacin, zinc as well as energy. Dietary quality of underreporting group was also worse than other groups. Proportion of subjects less than 3 food groups among 5 food group was higher in underreporting group. The number of foods eaten by underreporting group were also less than those of other groups. BMI and body weight were the largest in underreporting group(p<0.05) and the trial of weight reduction was shown higher trend(p<0.01). Different in PAC and other characteristics between underreporting group and other group were not significant. Not only dietary quantity but also dietary quality were worse in the underreporting group. Furthermore underreporting in college female students seemed to be affected by body weight and concern for weight reduction.

• 한국식생활문화학회지
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• 제21권6호
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• pp.679-684
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• 2006

In this experiment, I used three samples of oils. The oils that I used were hydrated soybean oil, pure soybean oil and regular soybean oil. The group of rice was fried in the each sample of oil that had not been used for a few seconds. Rice was used after frying at 230-235$^{\circ}C$ every four hours terms and total frying hours was 12 hours. The hydrated soybean oils was least affected in rancidity. The other two oils were more affected in rancidity than the hydrated soybean oil. However, the trans fatty acid in hydrated soybean oil was 36.5%. The diameter of the poped rice that was fried in pure soybean oil and regular soybean oil that had been used 12 for hours was reduced while the diameter of the popped rice fried in the hydrated soybean oil was not reduced. Also, the groups of rice fried in the pure and the regular soybean oil that had been used for 12 hours reduced the hardness in rice while the group that fried in the hydrated soybean oil at the 12th hour kept the hardness well. In sensory evaluation, rancidity order was found apparently in the pure soybean oil that had been used for 12 hour and in the regular soybean oil that have been used for eight hours and 12 hours. Only the hydrated soybean oil did not have distinctive rancidity order at all. The degree of the crispiness was reduced in the pure soybean oil and in the regular soybean oil at 12th hour frying. However, the hydrated soybean oil preserved the crispiness well until the end of 12 hours of frying. In overall preference test, the pure and regular soybean oil that had been used for 12 hour were not preferable. In conclusion, I found that the group fried in the hydrated soybean oil was better in every evaluation than the groups fried in the pure soybean oil and in regular soybean oil. The hydrated Soybean oil may be better to be used in food manufacturing if the trans fatty acid in the hydrated soybean oil can be reduced.

• 한국작물학회지
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• 제41권1호
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• pp.95-102
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• 1996

변화하는 환경조건에서 종자의 장기간 저장시발아율, 용출정도 및 수분흡수율을 밝혀서 장기저장 가능한 품종의 선발기준과 그의 특성을 알아보기 위하여 본 실험을 실시하였던 바, 다음과 같은 결과를 얻었다. 1. 콩나물재배기와 petri dish에서의 발아율은 20개월 저장시 품종간의 차이가 컸으며, 8개월 저장에서도 차이가 있었다. 2. 배축의 길이와 두께는 저장기간 간에 유의한 차이가 있었다. 3. 용출정도는 20개월 저장에서 팔달콩과 풀무원이 SS88038계통보다 2배 정도 높았다. 4. 초기 30분의 수분흡수율은 20개월 저장에서는 품종간 차이가 있었으며, 8개월 저장에서는 팔달콩과 풀무원이 SS88038보다 1.5배와 2배 빨랐다. 5. 발아율과 용출정도는 20개월 저장에서 고도로 유의한 부의 상관을 나타내었고, 100립중은 발아율 및 용출정도와 상관이 없었다. 6. 수분흡수율과 용출정도는 8개월 저장에서 침종 30분과 1시간에서 고도로 유의한 정의 상관을 나타내었고, 20개월 저장에서는 침종 30분, 1시간, 3시간에서 고도로 유의한 정의 상관을 나타내었으며, 주공의 열림과 수분흡술율은 상관이 없었다.

• Fisheries and Aquatic Sciences
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• 제5권1호
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• pp.21-27
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• 2002

Angiotensin I converting enzyme inhibitory activities of shelled krill (Euphausia superba) hydrolysates by autolysis and by hydrolysis with commercial proteases were analyzed. Among the proteases, Alcalase was the most effective protease for the hydrolysis of krill considering the degree of hydrolysis $(87.5\%)$ and the ACE inhibitory activity $(60\%)$. Four hour hydrolysis suggested as the most suitable and economic. In order to establish the optimum hydrolysis condition of krill, degree of hydrolysis and ACE inhibitory activity as affected by Alcalase concentration and water amount added were statistically analyzed by response surface methodology (RSM). The optimum hydrolysis condition was $2.0\%$ Alcalase hydrolysis in 2 volumes (v/w) of water at $55\% for 4 hr. The hydrolysate prepared from the optimum hydrolysis condition was fractionated by molecular weight. The lower molecular weight fraction showed the higher ACE inhibitory activity. $IC_{50}$ of the fraction under 500 Da was 0.57mg protein/mL.