• IMMUNE NETWORK
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• v.7 no.2
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• pp.66-74
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• 2007

Background: The genus Flavivirus consists of many emerging arboviruses, including Dengue virus (DV), Japanese encephalitis virus (JEV) and West Nile virus (WNV). Effective preventive vaccines remain elusive for these diseases. Mice are being increasingly used as the animal model for vaccine studies. However, the pathogenic mechanisms of these viruses are not clearly understood. Here, we investigated the interaction of DV and JEV with murine bone marrow-derived dendritic cells (bmDC). Methods: ELISA and FACS analysis were employed to investigate cytokine production and phenotypic changes of DCs obtained from bone marrow following flavivirus infection. Results: We observed that these viruses altered the cytokine profile and phenotypic markers. Although both viruses belong to the same family, JEV-infected bmDC produced anti-inflammatory cytokine (IL-10) along with pro-inflammatory cytokines, whereas DV infection induced production of large amounts of pro-inflammatory cytokines (IL-6 and TNF-${\alpha}$) and no IL-10 from murine bmDCs. Both flaviviruses also up-regulated the expression of co-stimulatory molecules such as CD40, CD80 and CD86. JEV infection led to down-regulation of MHC II expression on infected bmDCs. We also found that cytokine production induced by JEV and DV is MyD88-dependent. This dependence was complete for DV, as cytokine production was completely abolished in the absence of MyD88. With regard to JEV, the absence of MyD88 led to a partial reduction in cytokine levels. Conclusion: Here, we demonstrate that MyD88 plays an important role in the pathogenesis of flaviviruses. Our study provides insight into the pathogenesis of JEV and DV in the murine model.

• Nutrition Research and Practice
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• v.10 no.3
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• pp.313-320
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• 2016

BACKGROUND/OBJECTIVES: This study was conducted to compare the overall changes in dietary intake and metabolic syndrome risk parameters in Vietnamese marriage-based female immigrants over time. SUBJECTS/METHODS: The subjects of this study were 581 Vietnamese marriage-based female immigrants, who were recruited from local clinical centers in Korea. Baseline data were collected from 2006-2011 and the follow-up data were collected from 2012-2014. Dietary food intake was assessed by a 1-day 24-hour recall method. RESULTS: Compared to the baseline, the mean body weight, body mass index, waist circumference, high density lipoprotein (HDL)-cholesterol, systolic blood pressure and diastolic blood pressure increased while the fasting blood sugar, triglycerides and low density lipoprotein-cholesterol decreased at follow-up. The total consumption of foods such as vegetables/fruits/seaweeds/mushrooms, oil and fat, and eggs decreased during the follow-up period, whereas the consumption of sugars, beverages and meats increased. Partial correlation between the rate of change [(Follow-up - Baseline) / Baseline ${\times}100$] in metabolic syndrome risk parameters and food intake after controlling for confounding factors showed that the waist circumference was positively correlated with either the total plant food intake (r = 0.1042, P = 0.0129) or the total food intake (r = 0.0880, P = 0.0359). The plasma levels of total cholesterol (r = -0.1918, P = 0.0289) and HDL-cholesterol (r = -0.1424, P = 0.0007) were negatively correlated with the percentage of total intake from plant food, and HDL-cholesterol levels were positively correlated with the intake of total animal food (r = 0.0980, P = 0.0217). The serum C-reactive protein levels were positively correlated with the total intake of animal food (r = 0.2374, P < 0.0001) or the percentage of total intake from animal food (r = 0.1346, P = 0.0016). CONCLUSIONS: These results suggest that the change rate of dietary intake such as total plant food or animal food is associated with the change rates of metabolic syndrome risk parameters.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1285-1292
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• 2011

The characteristics of a semiconductor chiller system with EEV have been experimentally studied. Three experiments on temperature changes (increase and decrease), load variation, and control precision were conducted to investigate the operating characteristics of the semiconductor chiller. The power consumption was 8.9 kW during increase in temperature. The required time was 37.5 min for CH1 and 39.5 min for CH2. Moreover, the time required for falling temperature was 26.5 min. The control precision for partial load operation was relatively low compared to that of a full load operation. In addition, the CH2 equipped with a step motor showed better control precision. The power consumed by the chiller for process cooling water was 1.8 kW, which was one-half of that consumed during the refrigeration cycle. The objective of this study is to provide an optimal control guideline for the semiconductor chiller design.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.292-302
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• 2009

The wet oxidation of phenol has been investigated at temperatures from 150 to $250^{\circ}C$ and oxygen partial pressures from 25.8 to 75.0 bar with initial pH of 1.0 to 12.0 and initial phenol concentration of 10 g/l. Chemical Oxygen Demand COD has bee measured to estimate the oxidation rate. Reaction intermediates have been identified and their concentration profiles have been determined using liquid chromatography. The destruction rate of phenol have shown the first-order kinetics with respect to phenol and the changes in COD during wet oxidation have been described well with the lumped model. The impact of various homogeneous catalysts, such as $Cu^{2+}$, $Fe^{2+}$, $Zn^{2+}$, $Co^{2+}$ and $Ce^{3+}$ ions, on the destruction rate of phenol and COD has also been studied. The homogeneous catalyst of $CuSO_4$ has been found to be the most effective for the destruction of phenol and COD during wet oxidations. The destruction rate of formic acid formed during wet oxidations of phenol have increased as increasing temperature and $CuSO_4$ concentration. The final concentrations of acetic acid which has been formed during wet oxidations and difficult to oxidize have increased with reaction temperature and with decrease in the catalyst load.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.544-559
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• 2016

The purpose of this research is to analyze the mediating effects of knowledge management activities in the relationships between superiors' transformational leadership and their organizational commitment and between the their transformational leadership and knowledge management activities and organizational commitment by industry with 635 employees of large companies as the participants in this research. The results of this research can be summarized as follows. It was found that the superiors' transformational leadership had significant effects on their knowledge management activities and organizational commitment. Also, it was found that their knowledge management activities had significant effects on their organizational commitment. It was found that the superiors' transformational leadership had partial mediating effects with regard to the mediating role of their knowledge management activities in their organizational commitment. Finally, the results of the analysis by industry showed that the effects of the superiors' transformational leadership on their knowledge management activities were the greatest in the service industry and the effects of their knowledge management activities on their organizational commitment were also the greatest in the service industry. It was also found that the effects of the superiors' transformational leadership on their organizational commitment were the greatest in the IT industry. In this research, it was recognized that transformational leadership plays an important role as a prerequisite factor for promoting organizational effectiveness, and these results imply that transformational leadership means not only achieving goals, but also pursuing changes and innovation and, at the same time, developing the latent capabilities and strengths of the organization's members and promoting their confidence and passion by stimulating their positive strengths, so that they can achieve higher than expected outcomes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4322-4327
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• 2011

This study was conducted to analyze the influences of older volunteer activity. In detail, Administered on girl's maddle school students with the program's purpose on encouragement of positive career development. The study sample was taken from 30 students attending Y girl's middle school in Gyeonggi province, all of whom were regular volunteers at a near by rest home. The contents of the study and apparatus alike incorporated the use of a CAMI and CDS employed as a means of observing the changes before and after older volunteer activity experience in relation to five sub factors and career decision level. The data were analyzed by t-test using the SPSS Program. The results were as follows: First, it appears that older volunteer activity, in general, partial effect of improving a girl's middle school students' career attitude maturity. Second, it appears that older volunteer activity, improving effect a girl's middle school students' career decision level. Third, a girl's middle school students' career attitude maturity and career decision level had positive to advance more in particular in cases where the students' family also participated in older volunteer activity. As observed by the above results, a older volunteer activity experience should be an integral to a girl's middle school students' career education program plan as an effective means of enhancing their career attitude maturity and career decision level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.32-38
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• 2020

Cargo train braking uses the pressure changes in the air braking pipe to operate the braking tightening and releasing service repeatedly. Air-braking release failure means partial braking caused by a failure of the variable load valve after the driver handling the brake release. This phenomenon causes wheel flaws while driving a wagon, resulting in wheel breakage or train derailment. This study developed the air-braking release failure proof valve considering the technical requirements of the railway operation corporations. In addition, a durability test of the valve was carried out using a braking performance simulator, and its operating performance was evaluated from the pneumatic history under cyclic braking conditions. The warranty life of this valve was assessed by performing 160,000 cycles of testing of 12 prototypes in accordance with the zero-failure test method, considering the number of braking cycles while driving the wagon. During the durability test, the pneumatic input time, output time, and release velocity were almost constant. The warranty life of this valve was 59,860 times the 95% confidence level, which means that it can be operated without trouble for four years when the valve is installed in the bogie of the wagon.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.273-280
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• 2016

Purpose: This experiment was conducted to detect water stress in terms of the moisture content of cucumber seedlings under water stress condition using a hyperspectral image acquisition system, linear regression analysis, and partial least square regression (PLSR) to achieve a non-destructive measurement procedure. Methods: Changes in the reflectance spectrum of cucumber seedlings under water stress were measured using hyperspectral imaging techniques. A model for estimating moisture content of cucumber seedlings was constructed through a linear regression analysis that used the moisture content of cucumber seedlings and a normalized difference vegetation index (NDVI). A model using PLSR that used the moisture content of cucumber seedlings and reflectance spectrum was also created. Results: In the early stages of water stress, cucumber seedlings recovered completely when sub-irrigation was applied. However, the seedlings suffering from initial wilting did not recover when more than 42 h passed without irrigation. The reflectance spectrum of seedlings under water stress decreased gradually, but increased when irrigation was provided, except for the seedlings that had permanently wilted. From the results of the linear regression analysis using the NDVI, the model excluding wilted seedlings with less than 20% (n=97) moisture content showed a precision ($R^2$ and $R^2_{\alpha}$) of 0.573 and 0.568, respectively, and accuracy (RE) of 4.138% and 4.138%, which was higher than that for models including all seedlings (n=100). For PLS regression analysis using the reflectance spectrum, both models were found to have strong precision ($R^2$) with a rating of 0.822, but accuracy (RMSE and RE) was higher in the model excluding wilted seedlings as 5.544% and 13.65% respectively. Conclusions: The estimation model of the moisture content of cucumber seedlings showed better results in the PLSR analysis using reflectance spectrum than the linear regression analysis using NDVI.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.373-378
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• 2008

Purpose: In full thickness burn, the depth of burn is known to increase until around 1-3 days after the burn. However, no study on how the depth increase during the first 24 hours has been conducted. Therefore, the authors investigated how the depth of burn changes within the first 24 hours after the burn by using the standardized burn model. Methods: A total of four experiments on pigs were carried out for this study. Experiment 1 was performed to examine how temperature affects the depth of burn. The digitally controlled aluminum thermal block was set at different temperatures-80, 90 and 100 degrees in Celsius, respectively. Then the pig was exposed to the block for 15 seconds each time. The time exposed to heat was set as a variable for the Experiment 2. The temperature was maintained at 80 degrees Celsius, and the pig was contacted with the thermal block for 5, 10 and 20 seconds, respectively. The biopsy of the tissues were performed in one hour, 6 hours, 24 hours, and 7 days after the burn. After hematoxylin and eosin staining a percentage of the depth from a basement membrane of epidermis to the deepest tissue damaged by the burn against total dermal thickness was measured. Results: In Experiment 1, the depth of burn increased considerably as time passed by. At all three temperatures, differences in depths measured in 6 and 24 hours, and in 1 hour and 7 days were both significant. In addition, the depth deepened as the temperature went higher. In the case of Experiment 2, the depth of burn also increased significantly as time passed by. At all three times, differences in depth measured in 6 and 24 hours, and in 1 hour and 7 days were also significant. Moreover, the depth extended with longer contact time when it was compared according to the time. Conclusion: Full thickness burn progressed rapidly from 6 to 24 hours after the burn and the depth of burn was almost decided within the first 24 hours after the burn. On the other hand, partial thickness burn also advanced from 6 to 24 hours after the burn but the depth deepened at slower level.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.285-290
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• 2016

The purpose of our study was to retrospectively evaluate the cause of a decreased calcium score of follow-up studies on coronary artery calcium scores (CACs) computed tomography (CT). The subjects were healthy 100 people(85 males $60.6{\pm}6.9$ years, 15 females $67.2{\pm}7.3$ years). The subjects decreased CACs were divided into 4 subgroups depending on Agatston classification, minimal (1-10), mild (11-100), moderate (101-400), severe (400<). As a result of decreased CACs were scan location disagreement 51%, motion artifact 26%, equipment changes 14%, operator mistakes 5%, input miss 2%, image loss 1%, arrhythmia 1%. In the mild group, the most common decreased CACs were 49 people. In the minimal group, the most significant variation reduction has occurred to 6 people. Scan location disagreement was considered a partial volume effects due to the scan starting position. It showed less than 100 CACs a high variation (19.7%) in more than 100 CACs, a lower variation (2.2%), these could be seen that the variation range is different that can be tolerated according to the calcification score. Motion artifact factor was found in 26%, which is so closely related to the preceding tests that affect the higher heart rate like this pulmonary function test, exercise stress test.