• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.1-10
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• 2018

Recently, there has been rapid development in the field of flexible electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells and flexible sensors. Encapsulation process is added to protect the flexible electronic devices from exposure to oxygen and moisture in the air. Using numerical simulation, we investigated the effects of the encapsulation layer on mechanical stability of the silicon chip, especially the fracture performance of center crack in multi-layer package for various loading condition. The multi-layer package is categorized in two type - a wide chip model in which the chip has a large width and encapsulation layer covers only the chip, and a narrow chip model in which the chip covers both the substrate and the chip with smaller width than the substrate. In the wide chip model where the external load acts directly on the chip, the encapsulation layer with high stiffness enhanced the crack resistance of the film chip as the thickness of the encapsulation layer increased regardless of loading conditions. In contrast, the encapsulation layer with high stiffness reduced the crack resistance of the film chip in the narrow chip model for the case of external tensile strain loading. This is because the external load is transferred to the chip through the encapsulation layer and the small load acts on the chip for the weak encapsulation layer in the narrow chip model. When the bending moment acts on the narrow model, thin encapsulation layer and thick encapsulation layer show the opposite results since the neutral axis is moving toward the chip with a crack and load acting on chip decreases consequently as the thickness of encapsulation layer increases. The present study is expected to provide practical design guidance to enhance the durability and fracture performance of the silicon chip in the multilayer package with encapsulation layer.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.1
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• pp.1-10
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• 2017

Purpose: This study aimed to investigate the perception and emotional experiences in rare and intractable diseases for caregivers of pediatric patients with mitochondrial diseases in order to provide therapeutic interventions for patients, caregivers, and families. Methods: A total of 83 caregivers of pediatric patients with mitochondrial diseases were recruited from the pediatric mitochondrial disease clinics of the Gangnam Severance Hospital in South Korea. Participants completed the survey about their perception of mitochondrial disease and emotional experiences after the diagnosis, and these clinical data were analyzed accordingly. Results: Surveys from a total of 83 caregivers of patients were analyzed, and the patients' age ranged from 6 to 12 years (33%), followed by ages 1 to 6 years (30%). Children with mitochondrial diseases were between 0 and 0.5 years of age at the time of first symptom onset (43%), and the duration of illness lasted more than 10 years in most cases (42%). Prior to diagnosis of mitochondrial diseases, the amount of awareness the caregivers had was 'Not at all' for both rare and intractable diseases and mitochondrial diseases in 44 cases and 68 cases, respectively. For the caregivers' emotional experiences, the most common initial responses were 'Discouraged/despair', 'Helpless/lethargic', and 'Disconcerted'. 'Anxious', 'Committed to treatment', and 'Responsibility as family members' were the most common emotional responses from the caregivers, followed by 'Disconcerted' and 'Helpless/lethargic'. Conclusion: It is important to consider the level of perception and emotional experiences of caregivers and patients with rare and intractable mitochondrial diseases for planning treatment programs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.903-909
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• 2017

This study was conducted to develop Helianthus tuberosus (HT) juice mixed with dried bitter melon juice and assess its hypoglycemic effect in streptozotocin (STZ)-induced diabetic rats. HT juice mixed with 5.0% dried bitter melon juice was used in this study. Male Sprague-Dawley rats were divided into four groups (eight rats per group) and drunk each sample for 4 weeks: normal water [normal control (NC) group], STZ+normal water (STZ group), STZ+HT juice (HT group), STZ+HT juice mixed with 2.5% bitter melon juice (HT2.5 group), and STZ+HT juice mixed with 5.0% bitter melon juice (HT5.0 group). HT juice was diluted to 25% in distilled water and supplied to rats. Food intake, body weight gain, and food efficiency ratio were lower in the STZ group than in the NC group. HT, HT2.5, and HT5.0 groups showed higher parameters than the STZ groups. Water intakes were higher in the STZ group than in the NC group. After 3 weeks, HT, HT2.5, and HT5.0 groups showed lower parameters than the STZ group. After 1 week, blood glucose level of the STZ group ($476.7{\pm}22.8mg/dL$) was significantly higher than those of the HT group ($376.3{\pm}25.8mg/dL$), HT2.5 group ($405.2{\pm}35.1mg/dL$), and HT5.0 group ($342.8{\pm}29.7mg/dL$). After 4 weeks, blood glucose level of the STZ group were significantly higher than those of the HT, HT2.5, and HT5.0 group. Serum insulin levels of the HT group ($3.13{\pm}0.32ng/mL$), HT2.5 group ($3.40{\pm}0.23ng/mL$), and HT5.0 group ($3.48{\pm}0.43ng/mL$) were higher than that of the STZ group ($2.72{\pm}0.53ng/mL$). These results indicate that H. tuberosus juice mixed with dried bitter melon juice helps prevent or attenuate progression of diabetes in rats with STZ-induced diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.997-1011
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• 2017

This study aimed to evaluate the applicability of "food and nutrition standards for child care setting in the Seoul Metropolitan Government" using quantitative and qualitative surveys and lay the groundwork for future expansion. To evaluate the understanding and applicability of each item of the standards and utilize goodness of fit as an evaluation item to improve practicality of the child care center's health foodservice, we surveyed 82 child care centers, kindergartens, and community children centers in Seoul by e-mail through the Seoul Metropolitan Government in November 2015. Using focus group interviews with directors of child care centers and kindergartens as well as dieticians of child care support centers who had conducted public foodservice in Seoul, the appropriateness of each standard was finally reviewed, and amendments to extend this standard were derived. Results of the survey show an understanding of 86.9% and an applicability of 80.7%. Moreover, the applicability of the evaluation items for assessing improvement of health foodservice practices at the child care center was 82.6%. Qualitative evaluation of the applicability of standards through focus group interviews identified four factors for extended application: necessity of a guideline for separate food ingredient suppliers, conformity of the basis and purpose of the item, consideration of contextual situations, and necessity of establishing a Seoul-level foundation. Therefore, guidelines for the standards should be suggested for those providing public food services for children. Furthermore, separate guidelines categorized by items that food ingredient suppliers need to provide should be mandatory or recommended. Evaluation of the applicability of the standards suggests that revising and supplementing the guidelines in order to extend the standards can contribute to health promotion and a sustainable environment for children using public foodservice. Follow-up studies and supports are needed for sustainable food and nutrition management programs.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Journal of Life Science
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• v.28 no.9
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• pp.1056-1061
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• 2018

This article reports an agar-degrading marine bacterium and characterizes its agarase. The agar-degrading marine bacterium, KC-1, was isolated from seawater on the shores of Sacheon, in Gyeongnam province, Korea, using Marine Broth 2216 agar medium. To identify the agar-degrading bacterium as Agarivorans sp. KC-1, phylogenetic analysis based on the 16S rRNA gene sequence was used. An extracellular agarase was prepared from a culture medium of Agarivorans sp. KC-1, and used for the characterization of enzyme. The relative activities at 20, 30, 40, 50, 60, and $70^{\circ}C$ were 65, 91, 96, 100, 77, and 35%, respectively. The relative activities at pH 5, 6, 7, and 8 were 93, 100, 87, and 82%, respectively. The extracellular agarase showed maximum activity (254 units/l) at pH 6.0 and $50^{\circ}C$ in 20 mM of Tris-HCl buffer. The agarase activity was maintained at 90% or more until 2 hr exposure at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$, but it was found that the activity decreased sharply from $60^{\circ}C$. A zymogram analysis showed that Agarivorans sp. KC-1 produced 3 agar-degrading enzymes that had molecular weights of 130, 80, and 69 kDa. A thin layer chromatography analysis suggested that Agarivorans sp. KC-1 produced extracellular ${\beta}$-agarases as it hydrolyzed agarose to produce neoagarooligosaccharides, including neoagarohexaose (21.6%), neoagarotetraose (32.2%), and neoagarobiose (46.2%). These results suggest that Agarivorans sp. KC-1 and its thermotolerant ${\beta}$-agarase would be useful for the production of neoagarooligosaccharides that inhibit bacterial growth and delay starch degradation.

• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.486-496
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• 2018

In this study, we have selected Larix kaempferi as a study area in Woraksan National Park for understanding the ion index according to the difference of topography in national parks. We measured the weather and ion at two fixed points, ridge and valley, where the Larix kaempferi dominates in the same ecological structure in Woraksan National Park. The weather measurement results showed the average, maximum, and minimum temperatures of $28.22^{\circ}C$, $29.9^{\circ}C$, and $26.4^{\circ}C$, respectively at the ridge. The average, maximum, and minimum temperatures at the valley were $27.08^{\circ}C$, $27.8^{\circ}C$, and $25.5^{\circ}C$, respectively. The average, maximum, and minimum relatively humidities at the ridge were 67.02%, 75.25%, and 61.95%, respectively. he average, maximum, and minimum relatively humidities at the valley were 69.74%, 76.8%, and 63.75%, respectively. The average, maximum, and minimum amounts of positive ions generated in the ridge was $698.40{\pm}59.80ea/cm^3$, $885.88ea/cm^3$, and $597.88ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the ridge were $736.07{\pm}83.89ea/cm^3$, $934.53ea/cm^3$, and $599.32ea/cm^3$, respectively. The ion index is calculated to be 1.06. The average, maximum, and minimum amounts of positive ions generated in the valley were $1,732.49{\pm}354.08ea/cm^3$, $2,652.10ea/cm^3$, and $1,110.92ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the valley were $1,990.47{\pm}433.57ea/cm^3$, $3,126.75ea/cm^3$, and the minimum value was $1,352.17ea/cm^3$. The ion index is calculated to be 1.16. The difference in the amount of negative ions generated in ridge and valley was $1089.26ea/cm^3$, and the difference of the calculated ion index between the ridge portion and the valley portion was 0.10. The results of this study were provided as the reference weather data of national parks for health management.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.305-313
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• 2015

After Fukushima Daiichi nuclear disaster in 2011, study and maintenance of monitoring systems have been made at home and abroad. As concerns about radioactive contamination of water have increased in Korea, update of maintenance of managing radioactive materials in water is being made mainly by Ministry of Environment. In this study, we analysed current state of monitoring system modification in Japan, the country directly involved and neighboring country. According to the result, Japan modified the legislations first. Then Ministry of Education, Culture, Sports, Science and Technology (MEXT) provides theoretical background of radiological monitoring. And Ministry of the Environment actually watches state of water pollution in public waters and underground water. Finally related agencies like local government are monitoring current state of radioactive contamination in water environment. By region, local monitoring stations share the investigation of the whole country. Also, additional monitoring is running around nuclear facilities. After Fukushima disaster, monitoring for area near Fukushima is added. Among the reference levels, management target value of drinking water and tap water is 10 Bq/kg, and those of public water and underground water are 1 Bq/L. Measuring intervals varied from every hour to once a year, regularly or irregularly depending on the investigation. The main measuring items are air dose rate, gross ${\alpha}$, gross ${\beta}$, ${\gamma}$ radionuclide, Cs-134, Cs-137, Sr-89, Sr-90, I-131, and so on. In comparison, regulations about general public water in Korea need to be modified, while those about area near nuclear facility and drinking water are organized well. In future, therefore, domestic system would be expected to be modified with making reference to the guidelines like WHO's one. As good case of applying international guideline to domestic environment, Japanese system could be a reference when general standard of radioactivity in public water is made in Korea.

• Journal of Nutrition and Health
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• v.48 no.5
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• pp.407-418
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• 2015

Purpose: Given that the indicators related to chronic diseases are important to evaluating goals of the national health policy, the aim of this study was to develop dietary behavior items available in the Korea National Health and Nutrition Examination Survey. Methods: The dietary behavior items were developed based on the literature reviews, need assessment of the field, expert focus-group interviews, and expert advisory meeting. Questions for each dietary behavior item were developed by reflecting on environmental, personal, and behavior factors of the ecological frame and then revised through expert focus-group interview and expert advisory meeting. The understanding and reliability of the developed questionnaire were assessed by cognitive interview and test-retest reliability. Results: The developed items were sodium and salt intake, added and simple sugar intake, enough time to consume a meal for all ages, caffeine drinks and fresh/healthy food intake for children and adolescents, and limited dietary intake, fresh/healthy food intake for seniors. In most questions except some questions on sodium and salt intake, subjects understood over 70% and consistency of responses based on the kappa values was acceptable. Conclusion: Developed dietary behavior items are expected to be useful for evidence-based nutrition policy, interventions and research targeting dietary patterns through investigating and monitoring dietary behavior patterns.

• Journal of Nutrition and Health
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• v.48 no.5
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• pp.441-450
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• 2015

Purpose: The purpose of this study was to investigate the effects of hypertension relevant nutrition knowledge on practices for prevention of hypertension in Chinese college students studying in South Korea. Methods: We conducted a survey of 276 Chinese students studying more than three months in Korean universities who were aged 19 and older about hypertension and sodium relevant nutrition knowledge, intake of salty processed food, hypertension prevention practices, and stages of behavior change for hypertension. Results: The average score on the questionnaire for hypertension relevant nutritional knowledge was 40.62 out of 50 points, and the average score for sodium relevant nutritional knowledge was 24 out of 30 points. Kimchi was the most frequently eaten salty processed food. The average score for hypertension prevention practices was 3.10 out of 5 points. The behavior change stages for prevention of hypertension were contemplation (47.1%), action (32.2%), and pre-contemplation (20.7%). The students received high scores on nutrition knowledge and showed significantly higher scores on the action stage than on pre-contemplation or contemplation. Nutritional knowledge of hypertension and sodium showed positive correlation with hypertension prevention practices, whereas negative correlation with salty processed food intake. Conclusion: Development of an education program for Chinese students in Korea on hypertension and sodium relevant nutritional knowledge is needed so that they can practice for prevention of hypertension.