• The Korean Journal of Physiology and Pharmacology
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• 제11권6호
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• pp.233-237
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• 2007

Tropical natives (TROP) are capable of tolerating tropical heat because of their long-term adaptation to tropical environments. When exposed to heat stress, these natives tend to respond with lower sweat output, which is generally thought to be the result of heat acclimatization. The main objective of this study was to clarify central mechanisms inherent to suppressed thermal sweating in tropical natives (Malaysians) by comparing their sweating responses to those of temperate native (TEMP) (Koreans). This experiment was conducted in a thermoneutral climatic chamber ($24{\pm}0.5^{\circ}C,\;40{\pm}3%$ relative humidity). Heat loads were applied to each subject by the immersion of their lower legs in a hot water bath ($43^{\circ}C$ for 30 min). Sweat onset-time and sweat volume were compared between TROP and TEMP. The sweat onset-times on four selected points on the body ranged from 10.25 to 13.47 min in TEMP subjects, and from 16.24 to 17.83 min in TROP subjects (p<0.001). The local sweat volumes at the same sites ranged from 4.30 to $9.74 mg/cm^2$ in TEMP subjects, and from between 1.80 to $4.40mg/cm^2$ in TROP subjects (p<0.001). These results demonstrated a significant difference between TROP and TEMP subjects with regard to the manner in which they regulate their body temperatures when exposed to heat loads, and verified that long-term thermal adaptation blunts sweating sensitivities.

• 원예과학기술지
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• 제34권1호
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• pp.46-54
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• 2016

2-Oxoglutarate (2OG) acts as a signaling molecule and plays a critical role in secondary metabolism in a variety of organisms, including plants. Six 2-oxoglutarate (2OG) and Fe(II) oxygenase (2OGO) genes, VlCE2OGO1 [Vitis labruscana 2-oxoglutarate (2OG) and Fe(II) oxygenase 1], VlCE2OGO2, VlCE2OGO3, VlCE2OGO4, VlCE2OGO5, and VlCE2OGO6, which show different expression patterns upon transcriptome analysis of 'Campbell Early' grapevine exposed to low temperature for 4 weeks, were analyzed for their structure and expression. Comparison of the deduced amino acid sequences of the 2OGO genes from the V. labruscana transcripts revealed sequence similarities of 38.6% (VlCE2OGO1 and VlCE2OGO2) to 19.2% (VlCE2OGO2 and VlCE2OGO3). The lengths of these genes ranged from 1053 to 2298 bp, and they encoded 316 to 380 amino acids. The prediction of the secondary structure of the encoded proteins by Self-Optimized Prediction Method with Alignment (SOPMA) indicated that all the genes contained alpha helix (23.95 to 41.71%), extended strand (16 to 22.34%), beta turn (6.65 to 9.22%), and random coil (32.97 to 51.58%) in the analysis. Specific primers from unique regions in each gene obtained by alignment of nucleotide sequences were used in real time PCR for analysis of gene expression. All tested genes showed differential expression in grapevines exposed to low temperature. Of the six transcripts, VlCE2OGO1, VlCE2OGO2, and VlCE2OGO3 were up-regulated and VlCE2OGO4, VlCE2OGO5, and VlCE2OGO6 were down-regulated in response to cold treatments at all tested time points. The 2OG genes can be used for elucidation of mechanisms of tolerance to cold and as valuable molecular genetic resources for selection in breeding programs for cold-hardy grapevines.

• 한국압력기기공학회 논문집
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• 제17권2호
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• pp.119-125
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• 2021

Subsea pipelines are widely used to transport hydrocarbons from ultra-deep seawater to facilities on the coast. A sandwich pipe is a pipe-in-pipe system in which the annulus between the two concentric steel pipes is filled with polymer cores and fillers for insulation and structural reinforcement. Sandwich pipeline is always exposed to complex loading such as bending moment, bulking, internal and external pressures caused by installation, operation and environmental factors. This research provides insights into the structural integrity of sandwich pipeline exposed to complex loading conditions using a linear matching method (LMM). The finite element model of the sandwich pipeline has been generated from previous research, and the model validation is performed by comparing the results of the linear analysis between the two models. The temperature dependent material properties are used to simulate the behavior of real pipeline, and the elastic-perfectly plastic (EPP) model has been taken into account for the material non-linearity. Numerical results provide comprehensive insights into the structural response of the sandwich pipeline under monotonic and cyclic loading and provide notable points about the evaluation of the plastic collapse limit and the elastic shakedown limit of the sandwich pipeline.

• 대한치과교정학회지
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• 제54권3호
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• pp.153-159
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• 2024

Objective: This study aimed to assess the effects of commonly consumed hot drinks on the force decay of orthodontic elastomeric chains. Methods: This in vitro experimental study evaluated 375 pieces of elastomeric chains with six rings placed on a jig. Four rings were stretched by 23.5 mm corresponding to the approximate distance between the canine and the second premolar. Fifteen pieces served as reference samples at time zero, and 360 pieces were randomized into four groups: control, hot water, hot tea, and hot coffee. Each group was further divided into six subgroups (n = 15) according to the different exposure periods. The specimens in the experimental groups were exposed to the respective solutions at 65.5℃ four times per day for 90 seconds at 5-second intervals. The control group was exposed to artificial saliva at 37℃. The force decay of the samples was measured at 1, 2, 7, 14, 21, and 28 days using a universal testing machine. Data were analyzed using repeated-measures analysis of variance. Results: Maximum force decay occurred on day 1 in all groups. The minimum force was recorded in the control group, followed by the tea, coffee, and hot water groups on day 1. At the other time points, the minimum force was observed in the tea group, followed by the control, coffee, and hot water groups. Conclusions: Patients can consume hot drinks without concern about any adverse effect on force decay of the orthodontic elastomeric chains.

• 한국응급구조학회지
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• 제13권2호
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• pp.5-15
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• 2009

Purpose : This study was to examine the secondary traumatic stress(STS) and related factors of emergency medical technicians. Methods : This study was conducted among 190 emergency medical technicians, over the age of 25, with the 1st or 2nd grade qualification, who serve at fire stations in U and P city of Korea. The collected data for this study was analyzed using SPSS 12.0. Result : The average character type of A-type personality technicians was 43.25 points and the average of B-type personality technicians was 37.82 points. It suggested that the former was higher than the latter. State anxiety did not show statistically significant difference between A-Type group and B-Type group with the score of 48.51 for A-Type and 47.91 for B-Type. Physical symptoms showed statistically significant difference between the two groups with the higher score of 28.45 for A-type group than that of 28.13 for B-Type group. The level of STS related to the volunteers' job characteristics was found to be low when the volunteers were satisfied with their job and didn't want to transfer to another division. Those on duty who had slept more than seven hours that day had the highest points. The number of points was highest when the frequency for the onset of trauma was between 20~30 times. Furthermore it was found that for most technicians, 71.05%, the period of symptoms lasted for a few weeks at most, and this was where the STS was the lowest, whereas on the other hand the highest STS occurred when the symptoms lasted for a period of up to six months. The findings showed significant correlations with a relation of r=.24 between STS and level of anxiety and r=.45 between STS and physical symptoms. However, no significant correlation was found between the level of anxiety and physical symptoms. Conclusion : The more emergency medical technicians are exposed to accidents, the more serious the STS are. Those with an A-type personality are especially prone to have higher STS. The higher the STS level is, the higher the level of physical states and anxiety is.

• 대한수의학회지
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• 제46권3호
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• pp.255-261
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• 2006

Experimental animals have been used to biological and medical purposes and the animals must be, for these purposes, healthy and clean to microbial infection. However, the animals can be easily exposed to pathogenic microorganism via several routes. Of the routes, environmental conditions are the most important factors to keep the animals healthy and clean, especially air condition. Monitoring of air-condition has been required to keep the animal healthy and clean. However, any guideline is not available for experimental conditions with pigs. Therefore, the sampling times and points were compared in different conditions to establish an optimal protocol for monitoring of air borne bacteria. Tryptic soy agar(TSA), blood agar containing 5% defibrinated sheep blood and Sabraud dextrose agar(SDA) were used as media to capture total bacteria, pathogenic bacteria and fungi, respectively. Two methods, compulsive capture using an air-sampler and capturing fall-down bacteria were used to capture the microorganisms in the air. The points and time of capturing were different at each experiment. Air borne microorganisms were captured at three and five points in the open and closed equipments, respectively. Air was collected using an air-sampler for 1 min and 5 min and the agar plates as open status were left from 30 min to 2hr. At first, we monitored an experimental laboratory which dealt with several pathogenic bacteria and then, a protocol obtained from the investigation was applied to open or close experimental conditions with pigs. Number of bacteria was high from 10:00 to 15:00, especially on 13:30-15:30 but sharply decreased after 17:00. The tendency of the number of bacteria was similar between two methods even though the absolute number was higher with air sampler. Critical difference in the number of cells was observed at 5 min with air sampler and 2 hr with fall-down capturing method. However, 1 min with air sampler and 1 hr with fall-down capturing were the best condition to identify bacterial species collected from the air. Number of bacteria were different depending on the sampling points in closed condition but not in opened condition. Based on our results, a guide-line was suggested for screening air-borne microorganism in the experimental conditions with pigs.

• 한국콘텐츠학회논문지
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• 제17권11호
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• pp.371-382
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• 2017

본 연구는 콘텐츠산업정책을 포괄하는 문화정책에 대한 학술적 연구의 동향을 알고자 언어네트워크분석을 통해 국내의 가장 대표적인 문화정책 분야 전문학술지인 '문화정책논총'에 수록된 186편의 논문 주제어 832개를 대상으로 분석을 시도하였다. 시간적 범위는 한국연구재단 한국학술지인용색인 홈페이지(www.kci.go.kr)에 수록되어 있는 2008년 10월부터 2017년 1월까지로 하였다. 언어네트워크 분석은 주제어 빈도수, 밀도분석과 중심성을 지표로 분석하였으며, 이를 바탕으로 Netdraw 프로그램에 의한 시각화를 시도하였다. 언어네트워크분석 결과 가장 많은 빈도수를 기록한 주제어는 '문화'였고, '문화정책/행정', '문화산업/문화콘텐츠', '정책'이 최다의 빈도수를 기록한 그룹에 포함되었다. 빈도수가 높은 '문화정책/행정'과 '문화산업/문화콘텐츠'는 대부분의 중심성에서 우위를 차지했으나, 매개중심성은 낮아 다른 주제어들과의 중매 역할에는 한계를 드러냈다.

• Imaging Science in Dentistry
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• 제39권1호
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• pp.41-49
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• 2009

Purpose: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. Materials and Methods: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. Results: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. Conclusion: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

• 환경위생공학
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• 제17권3호
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• pp.99-109
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• 2002

Charcoal $tube/CS_2$ method are more popularly used than any other in the measurement of the working environment for the exposure evaluation of organic solvent, but it is some weak points that the lower accuracy can be obtained on the polar materials and within the range of the low concentration. Thus solvent desorption method has been developed to make accuracy higher and to overcome some weak points. However, because of high price of adsorption tube for thermal desorption and the short of study on its application to the working environment, it is not popularly used in the domestic industrial hygiene fields. This dissertation aims to develop thermal desorption and adsorption tubes for measuring organic solvents in the working environment, by comparing and analyzing breakthrough condition and adsorption capacity with ACF. Specific surface area of ACF used in this study is wider than the one of AC and micropore of ACF related with adsorption has been developed, and adsorption velocity and adsorption amount are very excellent by linking a pore of surface and an inside well into micropore. 1. Result of analysis on physical characteristics of adsorbent, the specific surface area of ACF was 1.3 times higher than that of AC. Distribution ratio of micropore related to adsorption was 94% on ACF and AC. Result of SEM, micropore of the AC is opened to the surface. In contrast, ACF shows that extremely fast adsorption speed. Because of micropore are exposed on the surface and penetrate through each other. 2. Breakthrough characteristics of adsorbents was not different from slop of breakthrough curve. The effluent concentration reaches 10% of initial concentration($C_{out}/C_{in}=0.1$, break point) of ACF was 30~316min longer than that of AC. Therefore, the adsorption capacities of ACF was 1.1~4.6 times higher than that of AC. ACF can be used as a proper adsorbent for measurement of organic solvent.

• 동아시아식생활학회지
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• 제24권3호
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• pp.291-300
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• 2014

This study determined the effects of television (TV) advertising restriction of Energy-Dense and Nutrient-Poor Foods on product and promotion activities by food companies producing or selling children's favorite foods. A survey using a selfadministered questionnaire was conducted via on-line or fax by marketers or R&D managers from 108 food companies. The data from 55 respondents (50.9%) were analyzed. Restriction exerted positive effects on food products with respect to compliance with labeling requirements (4.0 out of 5 points) and reinforcement of nutritional contents examination of new products (3.7 out of 5 points). Reformulations of products such as reduction of nutrients like sodium, sugar and fat were also reported. In addition, food companies underwent diverse changes in promotional activities, including modification of package designs and displays in stores, offering free gifts, discounts, etc. In conclusion, restriction of TV food advertising may contribute to improvement of children's food environment by encouraging food companies to make favorable product changes. On the other hand, the results also revealed that food companies adopt diverse marketing channels that are not yet under regulation. Hence, to make policies more effective, regulation needs to be extended from TV to other marketing channels to which children are easily exposed.