• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2076-2081
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• 2013

The objective of this study is to investigate the gastric emptying and gastrointestinal transit improvement effect of DL-methionine methylsulfonium chloride (MMSC) in functional dyspepsia animal models. Cisplatin causes nausea, vomiting, and inhibition of gastric emptying. Rats were divided into four groups: G1 (normal group), G2 (gastric emptying induced by cisplatin), G3 (gastric emptying induced by cisplatin with itopride 30 mg/kg pretreatment), and G4 (gastric emptying induced by cisplatin with MMSC 4 mg/kg pretreatment). Immediately after an oral administration of a liquid meal (phenol red), delayed gastric emptying was induced by cisplatin (10 mg/kg (i.p.)). After 20 min in the cisplatin administration, the animals were sacrificed. In rats treated with cisplatin, the gastric emptying rate was significantly reduced. On the other hand, MMSC reversed the reduction of gastric emptying induced by cisplatin. And also, MMSC caused to travel FITC-dextran more significantly longer distance than the control, which is based on the values of the mean geometric center in the atropine driven delayed gastrointestinal transit animal models. Furthermore, MMSC drastically increased the gastrointestinal transit in rats, considerably increased the values of the mean geometric center (MGC), compared to the control, which was comparable to that of mosapride. These results suggest that MMSC could be an effective component for the treatment of functional dyspepsia.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.37-45
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• 1983

유제품(乳製品)의 품질(品質)과 밀접(密接)하게 관련(關聯)되어 있는 skim milk protein의 가열(加熱)에 의(依)한 상대변화(狀態變化)를 단백질(蛋白質) 화학적(化學的) 측면(側面)에서 연구(硏究)하였다. 1. Skim milk 중의 calcium농도(濃度)가 높아질수록 가열시(加熱時) 점도(粘度)는 급증(急增)하였으며 gel화(化)가 일어나는 온도(溫度)는 점점 저하(低下)되었다. 이러한 사실(事實)로 보아 calcium ion은 유단백질(乳蛋白質)의 열안정성(熱安定性)에 결정적(結定的) 영향(影響)을 미치며 calcium존재(存在) 하(下)에서 가열(加熱)시킬 때에는 우유단백질(牛乳蛋白質)들을 균일분산계(均一分散系)로부터 불균일회합상태(不均一會合狀態)로 전이(轉移)시키는 것으로 결론(結論)되었다. 2. 일정(一定) 온도(溫度) skim milk의 안정성(安定性)에 대(對)한 가열시간(加熱時間)의 효과(效果)는 전혀 나타나지 않았다. 3. 등전침전(等電沈電)시킨 casein을 재용해(再溶解)시킨 후(後), skim milk 내(內)에서와 동일(同一)한 calcium농도(濃度) 환경(環境)으로 조절(調節)하고 가열(加熱)하였을 때 skim milk가 불안정성(不安定性)을 보이는 온도(溫度)보다도 저온(低溫)에서 침전(沈澱)으로 분리(分離)되었다. 따라서 가열(加熱)에 불안정(不安定)한 구분(區分)은 whey protein일 것으로 추정(推定)하였으며, 이는 skim milk 내(內)에서 casein에 의(依)하여 보호(保護)되는 것으로 해석(解析)되었다. 5. pH를 변경(變更)시킨 skim milk의 점도(粘度) 증가(增加)에는 calcium ion에 의(依)한 기여(寄與)가 컸으며, calcium은 유단백질(乳蛋白質)의 응집(凝集)을 촉진(促進)할 때 Ca-bridge로 작용(作用)하는 것이라고 결론(結論)되었다. 6. 비가열(非加熱)의 skim milk는 6개의 fraction으로 분획(分劃)되었음에 비(比)하여, $95^{\circ}C$에서 10분(分) 가열(加熱)했을 때는 fraction A 및 B가 소실(消失)되었고 새로운 fraction F@를 출현(出現)시켰다. 7. Electrophoretogram에서 fraction C 및 C#는 모두 3개의 band를, fraction F 및 F#는 모두 4개의 band를 나타냈으며 가열(加熱) 전후(前後)의 이동도(移動度)에도 차이(差異)가 없었다. Fraction D는 6개의 band로 D#에는 그 외(外)에도 3개의 band가 더 나타났다. fraction E 및 E#는 모두 4개의 band를 보였으나, 그 성분(成分)들의 이동도(移動度)는 모두 대응(對應)되지 않았다. Fraction A 및 B, 그리고 fraction D 및 E에는 가열(加熱)로 인(因)하여 변화(變化)를 받게되는 유단백성분(乳蛋白成分)이 포함(包含)되어 있을 것으로 추정(推定)되었다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.121-129
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• 1999

When continuous media are transmitted over the communication networks, asynchrony which can not maintain temporal relationships among packets may occur due to a random transit delay. There exist two types of synchronization schemes ; for guaranteed or non-guaranteed resource networks. The former which applies a resource reservation technique maintains delay characteristics, however, the latter supply a best-effort service. In this paper, I propose a intra-media synchronization scheme to transmit continuous media on general networks not guaranteeing a bounded delay tome. The scheme controls transmission times of the packets by estimating next delay time with the delay distribution. So, the arriving packets may be maintained within a limited delay boundary, and playout will be performed after buffering to smoothen small delay variations. The continually increasing delay due to network overload causes buffer underflow at the receiver. To solve it, the transmitter is required to speed up instantaneously. Too much increase of transmission-rate may cause network congestion. At that time, the transmitter drops the current packet when informed excessive delay from the receiver.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.19-27
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• 1976

Perilla (frutescens) seed oil, which is widely used as a source of vegetable oil in Korea, contains a strikingly large amount (58.4% of total fatty acids) of polyunsaturated linolenic acid (18 : 3) which is one of the essential fatty acids. Our hypothesis was that vitamin E contained in this oil would not be enough to prevent peroxidation of this polyunsaturated oil. A comparative study was carried out using rats and chicks devided into seven groups with various diet combinations emphasizing fat sources for the period of four weeks. The level of fat in each diet was 15% and animals were fed ad libitum. Various diet combinations were as follows; perilla seed oil and sesame seed oil with and without vitamin E supplementation, tallow as a saturated fat source and perilla seed hull group (10% at the expense of carbohydrate). The fat constituents of control group were consisted of 50% vegetable oil and 50% animal fat. A few important findings are as follows: 1. Rats fed perilla seed oil lost their hair focally around the neck and suffered from a bad skin lesion at the same place. In chicks, yellow pigmentation both of feather and of skin was clearly observed only in groups fed perilla seed oil with or without vitamin E supplementation. The basis of biochemical mechanisms of this phenomena remains as an important research interest. 2. The mean value for hematocrit was significantly lower for the chicks fed perilla seed oil than for those fed control diet. This result seems to be attributable to the effect on the red cell membrane known as peroxidation-hemolysis of vitamin E deficiency. 3. The serum cholesterol level was higher for the rats fed perilla seed oil than for those fed control diet, whereas in chicks the group fed perilla seed oil showed lower value than the control group indicating that different animal species could vary in their responses to the same diet. 4. In pathological examinations, the sign of hepatic fibrosis was seen in the perilla seed hull group and it was noticeable that the level of hepatic RNA was significantly increased in the rat recovering from vitamin E deficiency. It is hoped that more detailed studies on perilla seed oil and hulls will soon be carried out in many aspects especially i) at various levels of fat in the diet, ii) in relation to dietary selenium level and iii) to find an optimum level of dietary essential fatty acids in terms of P/S ratio using various animal species. In the mean time, the public should be informed to preserve this particular oil with care to minimize fatty acid oxidation and should be discouraged from overconsuming this oil. This study was supported by UB (United Board) Research Grant (Graduate School, Yonsei University, Seoul, Korea)

• 대한공업교육학회지
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• v.30 no.1
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• pp.106-119
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• 2005

Many problems with the offline class, which is the traditional education type in corporations or universities, were indicated and people hoped that e-learning, which is web-based instruction, would solve these problems. However, e-learning also has weak points in that it should be self-paced and media-based in many ways. Therefore, when considering the good and weak points of offline classes and e-learning, blended learning seems to be necessary. Until now, blended learning has usually been used in corporations, and there have been almost no studies on the effectiveness or management of blended learning in universities. Thus, in this study, I would like to design blended classes, manage them at the level of university classes, and verify the effectiveness of blended classes, by comparing academic achievement, student participation, and student satisfaction. The subject students who signed up for Computer & Technology at C University in 2005 were divided into three study groups: offline class, online class, and blended class. The offline class was taught using the traditional class teaching method. For the online class and the blended class, multimedia contents were developed and a different LMS was used. The results of 13 weeks of teaching are as follows. For the academic achievement in the offline, online and blended classes, there was no statistically significant difference (f=2.387, p=.096). But when comparing the average achievement, the average of the blended class was higher than that of the other classes, so that it can be said that the blended class has positive effects on academic achievement. Second, when comparing the learners' participation in the online class and the blended class, the total posts were 85 and 138 respectively, which shows a considerable difference. The hit counts for each post in the online class and the blended class are 10 and 20, respectively. Moreover, the login counts for subjects are 3 in the online class and 4 in the blended class. In the questionnaire for the students' academic satisfaction in the online class and the blended class, all of the 15 items showed higher satisfaction in the blended class. Considering all these results, if adequate media are properly combined, the blended class is better than either the pure online class or the pure offline class.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.117-133
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• 2008

Objectives : Since ancient times, Koreans have applied medicinal spabaths for treatment of various diseases. The objective of this study was to investigate the effect of strontium, one of the common ingredients of such baths, experimentally on acute skin barrier damage. Materials and Methods : Male hairless mice, average weight 20g, were divided into six groups. Each group consisted of five mice. The first was the normal, non-treated group. The second was the control group with acute skin barrier damage intentionally induced by TS. The third was the Ba-Sr1 group bathed in 1mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fourth was the Ba-Sr7 group bathed in 7mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fifth was the Sr1 group bathed in 1mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. The sixth was the Sr7 group bathed in 7mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. External changes of skin, skin erythema level, transepidermal water loss level, and GOT and GPT level of each group were checked immediately before and after TS, 3 hrs, 5 hrs and 24 hrs after inducing acute skin barrier damage. Then, tissue samples were made and examined for damage to epithelial cells, stratum corneum, change of mucous polysaccharide in dermis and amount of mast cells. Statistical analysis was performed by one way-ANOVA, Scheffe and Duncan for a post hoc test and pairwise comparison for comparing for difference between each time. Statistical significance was achieved if the probability was less than 5% (p<0.05) Results : 1. From skin erythema and TEWL level indicating the function of the skin barrier, we can know that it is helpful to the skin barrier to bathe in a water solution including a low concentration of strontium. 2. In the control group with acute skin barrier damage induced by TS, skin barrier damage persisted until 3-5 hrs and recovered after 5-24 hrs. Differently from the control group, in the case of taking a bath in a water solution including strontium, skin barrier damage recovered after only 3-5 hrs. Therefore, the bath with a water solution including strontium can promote recovery of the skin barrier. 3. Bathing in water solution including a higher concentration of strontium was more beneficial to recovery of skin barrier damage. 4. There was no influence on serum GOT and GPT from bathing in a water solution including strontium. Conclusions : The strontium was effective for recovery and mitigation of acute skin barrier damage induced by tape stripping. I suggest that strontium (Sr) can be used as an external treatment medicine, addedinto bath water to treat acute skin barrier damage.

• Composites Research
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• v.12 no.3
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• pp.75-83
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• 1999

The thermal properties of carbon/phenolic and silica/phenolic ablative composites were investigated by measuring the heat capacity, thermal diffusivity and thermal conductivity. The heat capacities of carbon/ phenolic and silica/phenolic composites were calculated from differential scanning calorimeter curve. The thermal diffusivities of carbon/phenolic and silica/phenolic composites were measured by the laser flash method with varying laminated direction, i.e., with laminar direction and across laminar direction. The thermal diffusivities decreased with increasing temperature. The thermal conductivities of carbon/phenolic and silica/phenolic composites were calculated using the heat capacity, density and thermal diffusivity. The thermal conductivities increased with increasing temperature. The thermal conductivity of with laminar direction is two times higher than that of across-laminar direction in carbon/phenolic composite due to the directionality of thermal conductivity of carbon fiber. The thermal conductivities of two dimensional fiber reinforced composites were analyzed using the conductivities of constituents and volume fraction of each constituent. The thermal conductivities of carbon fiber and silica fiber were calculated from thermal conductivities of carbon/phenolic and silica/phenolic composites. The thermal conductivities of carbon/phenolic and silica/phenolic composites at RT were predicted from thermal conductivities of fiber and resin with varying the volume fraction of fiber.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.419-426
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• 2004

This experimental study was designed to investigate the effects of Yukgunja-tang(YGJT) on the inhibition of cerebral ischemia in rats. And We measured regional cerebral blood f1ow(rCBF) and pial arterial diameter(PAD) in cerebral ischemic rats, and cytokines production in serum Of cerebral ischemic rats. The results were as follows; Both rCBF and PAD were significantly and stably increased by YGJT(10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion(MCAO) 1 hr, IL-1β and TGF-β production of sample group were similar to that of control group, but sample group was decreased TNF-α production compared with control group, and was significantly increased IL-10 production in compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1 hr, sample group was significantly decreased IL-1β and TNF-α production compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was significantly increased IL-10 production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, and sample group was decreased TNF-α production in compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was increased IL-10 production compared with control group. This results were suggested that YGJT has inhibitive effect on the brain damage by inhibited IL-1β production and TNF-α production, but accelerated IL-10 production. We thought that YGJT should have an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• Journal of Korean society of Dental Hygiene
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• v.8 no.1
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• pp.73-91
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• 2008

In order to investigate the complaint rates of subjective fatigue symptoms and the degree of job-satisfaction among dental hygienists based on their socio-demographic and job characteristics and to find out the factors related with subjective fatigue symptoms and job satisfaction. The study subjects were recruited from 274 dental hygienists who worked at dental hospitals and clinics in Daejon city and South Chungcheong Province during the period between Jan. 5 and Feb. 11, 2008. They were asked to complete the self-administered questionnaires asking about their socio-demographic characteristics. job characteristics. daily life styles, job satisfaction and subjective fatigue symptoms, and the major finding of the results were as follows : 1. The mean scores of job satisfaction were 3.12V0.47 of the total full scores(5.00). and the highest scores were in the sub-domain of interpersonal relationship. and the lowest scores were pay. The scores of job satisfaction by socio-demographic characteristics and daily life styles were not significantly differences, but in job characteristics, significantly increased with those feeling satisfied with their job. those with appropriate amount of duty amount, those free of jop autonomy, those feeling satisfied with their monthly income. satisfactory personal relations at work. 2. The mean scores of subjective fatigue symptoms were 27.6V10.9 of the total full scores(60.0), and the highest scores were in the sub-group of bodily projection of fatigue(Group III), and they were followed by difficulty in concentration(Group II). dullness and sleepness(Group I) in their decreasing order of magnitude. The scores of job satisfaction by socio-demographic characteristics and daily life styles were significantly increased with the group of lower age, the group of irregularly breakfast habit and the worse subjective health status. Based on job characteristics. the score of subjective fatigue symptoms were significantly increased with those group of lower clinical career and monthly income, those feeling unsatisfied with their job, those with inappropriate amount of duty amount. those satisfactory personal relations at work 3. The correlation of subjective fatigue symptoms with job satisfaction showed a negative correlation with rM-0.198(pM0.000), and job satisfaction were higher according to the lower subjective fatigue symptoms. The correlation among the scores of sub-domain of job satisfaction and the sub-group of subjective fatigue symptoms were significantly positive correlation. 4. The affecting factors of significance on job satisfaction included clinical career, duty amount salary satisfaction, with the explanatory power of 32.9%. Those on subjective fatigue symptoms included the eucation and the subjective health statuts, with the explanatory power of 20.8%. When considering these results, the job-satisfaction and the subjective fatigue symptoms were significantly correlated with the job related factors than factors of socio-demographic characteristics and daily life styles. In addition. if job environments of dental hygienist can improved. their job-satisfaction and subjective fatigue symptoms are suggested to be betters.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1217-1226
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• 2004

A psychrotrophic bacterial strain, Pseudomonas fluorescens BM07, synthesized unsaturated fatty acids (UFA) from fructose in response to lowering of growth temperature, and incorporated them into both polyhydroxyalkanoic acid (PHA) and membrane lipid. The blocking of PHA synthesis by adding 5 mM 2-bromooctanoic acid to the growth medium, containing 70 mM fructose, was found to be a useful means to profile the composition of membrane lipid by gas chromatography. As the growth temperature changed from 35 to $50^{\circ}C$, the total content of two UFA, 3-hydroxy-cis-5­dodecenoic acid ($C_{12:1}$) and 3-hydroxy-cis-7-tetradecenoic acid ($C_{14:1}$), in PHA increased from 31 to 44 $mol\%$. The growth at lower temperatures also led to an increase in the level of two major UFA, palmitoleic acid (C16:1 cis9) and cis-vaccenic acid (C18:1 cis11), in membrane lipid. A fraction of these membrane-lipid UFA was converted to their corresponding cyclopropane fatty acids (CFA). The CFA conversion was a function of culture time, exhibiting biphasic increase before and after entering the stationary phase. However, pH changes in growth media had no effect on the CFA conversion, which is contrary to the case of E. coli reported. The cells grown at $30^{\circ}C$ responded to a cold shock (lowering the medium temperature down to $10^{\circ}C$) by increasing the level of C16:1 cis9 and C 18: I cis II up to that of $10^{\circ}C$-grown control cells and concomitantly decreasing the relative level of cis-9,10­methylenehexadecanoic acid (the CFA converted from C16:1 cis9) from 14 to 8 $mol\%$, whereas the 10-grown cells exhibited little change in the lipid composition when exposed to a warmer environment of $30^{\circ}C$ for 12 h. Based on this one- way response, we suggest that this psychrotrophic strain responds more efficiently and sensitively to a cold shock than to a hot shock. It is also suggested that BM07 strain is a good producer of two unsaturated 3-hydroxyacids, $C_{12:1}\;and\;C_{141:1}$.