• Journal of Chest Surgery
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• 제33권8호
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• pp.605-612
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• 2000

Background: Ischemic preconditioning enhances the tolerance of myocardium against ischemia/reperfusion injury, with the enhancement of the recovery of post-ischemic myocardial function. This study was disigned to assess whether the protective effect of ischemic preconditioning could provide one additional hour of myocardial preservation in four hour myocardial ischemia in a rate heart. Material and method: Fourty four Spargue-Dawley rats, weighing 300~450gm, were divided into four groups. Group 1(n=7) and group 3(n=12) were subjected to 30 minutes of aerobic Langendorff perfusion without ischemic preconditioning and then preserved in saline solution at 2~4$^{\circ}C$ for 4 hours and 5 respectively. Group 2(n=7) and group 4(n=18) were perfused in the same way for 20 minutes, followed by 3 minutes of global mormothermic ischemia and 10 minutes of perfusion and then preserved in the same cold saline solution for 4 hours and 5 hours respectively. Heart rate, left ventricular developed pressure(LVDP), and coronary flow were measured at 15 minutes during perfusion as baseline. Spontaneous defibrillation time was measured after reperfusion. Heart rate, LVDP, and coronary flow were also recorded at 15 minutes, 30 minutes, and 45 minutes during reperfusion. Samples of the apical left ventricular wall were studied using a transmission electron microscope. Result: Time of spontaneous defibrillation(TSD) was significantly longer in group 4 than in group 1(p<0.001), and TSD in group 1 was significantly longer in comparision to that of group 2(p<0.05). Heart rate at 45 minutes was significantly higher in group 1 than in group 4(p<0.05). Heart rate at 15 min was significantly higher in group 2 than in group 1(p<0.001) and in group 4 than in group 3(p<0.05). Left ventricular developed pressure(LVDP) at 30 minutes and 45 minutes was higher in group 1 than in group 4(p<0.01), LVDP at 45 minutes was higher in group 4 than in group 3(p<0.05). Rate-pressure product(RPP) at 30 minutes and 45 minutes was higher in group 1 than in group 4(p<0.05). RPP at 15 minutes was higher in group 2 than in group 1(p<0.01). RPP at 30 minutes and 45 minutes was higher in group 4 than in group 3(p<0.05). Group 2 showed relatively less sarcoplasmic edema and less nuclear chromatin clearance than group 1. Group 4 showed less myocardial cell damage than group 3, group 4 showed less myocardial cell damage than group 3, group 4 showed more myocardial cell edema than group 1. Conclusion: Ischemic preconditioning enhanced the recovery of postischemic myocardial function after 4 hours and 5 hours preservation. However, it was not demonstrated that ischemic preconditioning could definitely provide one additional hour of myocardial preservation in four hour myocardial ischemia in a rat heart.

• 생명과학회지
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• 제31권10호
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• pp.960-968
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• 2021

미세조류 연구는 18세기 후반부터 시작된 이후 생물산업에서 가장 중요한 생물자원으로 인식되어 왔다. 특히 미세조류의 산업 활용에 초점을 맞춘 식품/사료 및 생리 활성 화합물에 대한 초기 주요 연구 분야는 현재 대체 에너지 자원, 탄소 배출 저감 및 폐수 처리를 포함한 환경 연구 분야로 더욱 확대되고 있다. 하지만 그 산업적 활용의 중요성에도 불구하고 미세조류 배양의 장기 보존과 관련된 기초 연구 분야는 많은 주목을 받지 못하고 있다. 그러나 생물학적으로 활성을 띄는 안정적인 미세조류 배양체 보존은 이러한 미세조류의 산업적 활용을 더욱 부각시킬 수 있는 핵심적인 성공요소이다. 따라서 본 총설은 조류(algae)의 분류체계에서 가장 큰 분류군을 차지하는 녹조류(Chlorophyceae)를 포함하여 현재까지 개발된 다양한 최첨단 미세조류 냉동보존기술을 조사하였다. 또한, 국내 생물자원은행 및 국제 미세조류 자원은행에 기탁된 생물학적으로 활성을 띄는 미세조류 배양체를 보존·유지하기 수행하고 있는 보존 기술과 함께 동결보존 시 온도조절 효과, 보존제 효과 등 미세조류의 성공적인 동결보존 기술과 관련된 주요 요인들을 조사하였다. 본 연구를 통해 확인된 결과를 살펴보면, 미세조류의 형태 및 생리학적 다양성으로 인해 현재로서는 범용적으로 사용할 수 있는 표준 미세조류 장기 보존 방법이 없다는 것을 확인하였다. 따라서, 이러한 문제를 극복하기 위해서는 미세조류의 분류학적 체계를 명확하기 위한 종 특이적 바이오마커의 개발과 종 특이적 동결보존 방법에 기반한 체계적인 접근을 위한 기초 연구 분야에 대해 훨씬 더 많은 노력이 필요함을 확인하였다.

• 한국식품저장유통학회지
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• 제23권2호
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• pp.233-238
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• 2016

추출방법을 달리하여 달맞이꽃 에탄올 추출물의 주요성분과 항산화 및 항균 활성을 측정하였다. 상온교반 추출(SE, stirrer extraction), 초음파 추출(USE, ultrasonification extraction), 환류 추출(RE, reflux extraction), 고온가압추출(AE, autoclave extraction), 저온고압추출(LE, low temperature high pressure extraction)법을 사용한 결과 RE법이 추출수율(46.33%), 총 폴리페놀(463.05 mg GAE/g)과 플라보노이드(71.71 mg RHE/g) 함량이 다른 추출방법 보다 높았다. 달맞이꽃 추출물은 B. cereus에 대한 항균활성이 나타났으며, 추출방법에 따른 차이는 나타나지 않았다. DPPH와 ABTS radical 소거능, 환원력, 철이온 흡착능 시험에서도 RE법을 이용한 추출물이 각각 74.40%, 65.29%, 1.370 ($OD_{700}$), 90.14%를 나타내어 다른 추출방법에 비해 높았다. 달맞이꽃 추출물은 항산화 활성이 우수하여 유용한 천연물 소재로 사용이 가능하며, B. cereus가 주 원인이 되는 식중독의 예방이나 오염된 식품의 보존성 증진을 위한 천연 소재로 할용이 가능할 것으로 판단된다.

• 한국식품저장유통학회지
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• 제7권4호
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• pp.389-394
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• 2000

단감의 수확 및 저장 중에 발생한 불량과실을 이용할 목적으로 분말화하기 위한 기초연구로서 본 실험을 행하였다. 일반성분 조성은 조단백질, 조지방, 조회분의 순으로 열풍건조 처리구는 0.9-1.1%, 15.0-39.0%, 2.3-3.3%이었으며, 동결건조 처리구는 1.3-2.2%, 27.0-49.0%, 2.5%로 나타났다. 무기성분 조성은 열풍과 동결건조 처리구 모두 potassium, magnesium, phosphorus; calcium, sodium이 주요 무기성분이었으며, 다른 미량원소는 약 3.00ppm 이하였다. 주요 지방산 조성은 열풍과 동결건조 처리구에서 capric acid, lauric acid tridecanoic acid, palmitic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid 순으로 나타났다. 동결건조 처리구의 아미노산 조성은 aspartic acid, glutamic acid가 주요 아미노산이었다. 전체적으로 열풍건조 처리구보다는 동결 건조 처리구가 다소 높은 결과를 보였다. 열풍과 동결건조에 의한 분말 제조에서는 변색과 영양적인 측면을 고려할 때 열풍건조 보다는 동결건조가 우수한 결과를 보였으며, 열풍건조가 시간은 단축되었으나 얇게 펴서 건조해야 하는 단점이 있었으며, 단순한 열풍건조 만으로는 대량생산에 의한 분말 제조는 어렵고 좀더 보완적인 방법이 강구되어야할 것으로 생각된다. 이에 반해 동결건조에 의한 건조방법은 건조시간이 다소 걸리기는 했으나 딱딱해지거나 변색의 우려가 없으며 영양학적으로도 매우 안정적이었다. 이상의 결과를 평가해 볼 때 열풍건조에 의한 분말 제조는 구체적인 보완이 필요하며, 동결건조에 의한 분말 제조가 열풍건조에서보다 우수한 것으로 결과가 나타났다. 따라서, 파찌감의 분말건조 방법은 동결건조가 효율적일 것으로 생각된다.

• 한국동물위생학회지
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• 제22권1호
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• pp.93-101
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• 1999

This test process on screening method for the detection of residual antibiotics in milk is simple, economic, sensitive to residual antibiotics and was given approval international organs. Thus, this study was carried out the comparison of Disk assay method and TTC-II method for sensitivity and minimum detectable range of antibiotics in raw milk. The results of this study was summarized as follows ; 1. The number of samples requested for treatment of mastitis was 198 samples. Comparison or analytical results among the methods of TTC-II, disk assay and Delve sp was that TTC-II 37 samples(18.6% ), Disk assay 125samples(63.1%), Delve SP 130 samples(65.7% ) reacted positively. Conformity rate of Delve SP and Disk assay was 70%. 2. Detectable limits of disk assay method in some antibiotics were more sensitive than those of official method(0.05-0.0025ppm in the $\beta$-lactams, 1ppm in two aminoglycoside, 0.2 ppm in one tetracycline, similar in one macrolide) 3. For sensitivity of residual sulfonamides TTC-II was much more sensitive than disk assay. Detectable limits of sulfamethazine and sulfadimethoxine were 30 to 50ppm levels. 4. The best medium preservation period is 1-2 days. 5. Concentration of brome cresol purple related to resistance for B stearothermophilus culture was 24ppm/ml. These results show that disk assay method for screening detection of antibiotics residuces in milk is worthy of use.

• 보존과학연구
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• 통권28호
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• pp.105-119
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• 2007

Restoration of earthenware is largely composed of selection of clay, making(forming), and firing. This study lays emphasis on the making method and open-air firing. For making methods, This study used coiling method partly with priority given to ring method. The most significant feature of this restoration work is the making method of tap-forming, in which 외박자(out tap instrument) and 내박자(inter tap instrument) would be tapped and formed. For firing, This study used open-air firing method in the most primitive way. This method needs no special device and equipment and makes the work more simple and easy. The previous study was on the making method by archeological and preservation-scientific research but this study emphasized the restoration work in an actual earthenware maker's position. Through the result of this study, This study wish this would be an opportunity to present another model of various restoration methods for other researchers those who wanted to participate in the restoration and openair firing.

• 한국멀티미디어학회논문지
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• 제22권8호
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• pp.950-959
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• 2019

The purpose of this study was to investigate the effect of integrated teaching and learning method using augmented reality for effective promotion of child - friendly attitude and environmental preservation attitude and explored its applicability. For this purpose, based on the augmented reality fairy tale, we designed an experience - oriented integrated teaching and learning method such as reading book, story - telling, drawing, environmental conservation practice activity. The experimental group was divided into two groups: augmented reality reading fairy tales (A) and children's book reading fairy tales (B). First, interest, immersion, and empathy were higher in the application environment of integrated learning teaching method based on Augmented Reality. Second, there was no difference between the two groups in content understanding. Third, in terms of expressiveness, it was verified that various expressions were expressed in the applying environment of the integrated teaching - learning method based on augmented reality through drawing activities. Fourth, in practice activities, more students were practicing in the augmented reality - based integrated teaching - learning method applied environment, and the number of practice activities of individual students was also confirmed. This study suggests that the application of the integrated teaching and learning method can enhance the effect of education when using the smart teaching media using the augmented reality in early childhood education.

• 한국물환경학회지
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• 제34권1호
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• pp.67-76
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• 2018

There are 34 mega-cities with a population of more than 10 million in the world. One of the highly populated cities in the world is Seoul in South Korea. Seoul receives $1,140million\;m^3/year$ for domestic water, $2million\;m^3/year$ for agricultural water and $6million\;m^3/year$ for industrial water from multi-purpose dams. The maintenance water used for water conservation, ecosystem protection and landscape preservation is $158million\;m^3/year$, which is supplied from natural precipitation. Recently, the use of the other water for preservation of water quality and ecosystem protection in urban areas is increasing. The objectives of this study is to develop the seasonal forecast method of environmental water in urban areas (Seoul, Daejeon, Gwangju, Busan) and to evaluate its predictability. In order to estimate the seasonal outlook information of environmental water from Land Surface Model (LSM), we used the observation weather data of Automated Synoptic Observing System (ASOS) sites, forecast and hind cast data of GloSea5. In the past 30 years (1985 ~ 2014), precipitation, natural runoff and Urban Environmental Water Index (UEI) were analyzed in the 4 urban areas. We calculated the seasonal outlook values of the UEI based on GloSea5 for 2015 year and compared it to UEI based on observed data. The seasonal outlook of UEI in urban areas presented high predictability in the spring, autumn and winter. Studies have depicted that the proposed UEI will be useful for evaluating urban environmental water and the predictability of UEI using GloSea5 forecast data is likely to be high in the order of autumn, winter, spring and summer.

• 한국식품조리과학회지
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• 제16권1호
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• pp.27-35
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• 2000

This study intended to find out what the male and female university students in Kyung-book area think about Korean traditional foods, how much they use them, and how their life styles affect their estimates on traditional foods. They evaluated the aspects of traditional foods highly in the order of nutrition(6.07), taste(5.96), appearance(5.40), color(5.33), preservation after cooking(4.82), cost(4.63), and cooking method(4.43). Female students had higher estimates on traditional foods than male students. There was no significant difference in the evaluation between the students raised in rural and urban areas if they had the same educational level. Regardless of gender, Kimchi was most preferred followed by boiled rice, pot stew, grilled fish, and beef out of 25 traditional foods. In the correlation among the evaluation factors and uses of traditional foods, those with high evaluation on traditional foods(r=0.282, p<0.01) and the families with higher income(r=0.316, p<0.01) made more use of traditional foods. For the life style, leisure-valuing type was the greatest part(39.4%) in male students and altruistic type(31.9%) in female students. The altruistic type comprised of the greatest part(34.8%) among the students raised in urban areas and the leisure-valuing type(40.0%) among those raised in rural areas. The altruistic type students put high values on taste, nutrition, appearance, color, and preservation after cooking of the traditional foods. The egocentric type gave high values on cost and cooking method. However, there were no significant differences among the types in every item. The altruistic type put the highest and the leisure-valuing type put the lowest value on traditional foods, respectively, however, it was not significantly different. The individuality-centered type made the most use of traditional foods, whereas the leisure-valuing type made the least(p<0.05).

• 한국식품저장유통학회지
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• 제15권6호
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• pp.791-795
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• 2008

아황산가스 발생제를 자가 제조하여 포도의 저장 중 병해발생 방지에 이용하는 방법을 확립하기 위하여 sulfite 화합물의 아황산가스 발생 정도와 지속 기간을 측정하고 아황산가스 발생 조절 및 간이 검출 방법을 개발하였다. 포도의 저장 중 잿빛곰팡이병을 일으키는 B. cinerea의 포자 발아와 균사생장은 각각 400 ppm과 3200 ppm의 아황산가스 농도 조건에서 억제되었다. 5종류의 sulfite 및 bisulfite 화합물 중 sodium hydrosulfite는 아황산가스 발생량이 가장 높았으며 이를 비닐 포장하여 포장의 pinhole수를 조절하거나 산 또는 알카리의 pH 조절제를 혼합하면 가스 발생량과 발생 지속 기간을 조절할 수 있었다. Malachite green 용액은 아황산가스에 의해 정량적으로 탈색되어 아황산가스 검출에 이용할 수 있었으며 여과지에 흡수하여 건조할 경우 아황산가스 검출지로 활용할 수 있었다. MBA 포도를 속효성과 지효성의 아황산가스 발생제를 동시에 처리하여 저온 저장할 경우 병해 발생을 감소시킬 수 있었다.