• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.273-277
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• 2014

This paper presents a brief historical review of various attempts to estimate the age of the Earth, and reappraises the study of Patterson (1956) which revealed for the first time that the age of the Earth is $4550{\pm}70Ma$ by measuring Pb isotope ratios of several meteorites and a marine sediment. The standard model for the planetary formation of early solar system is: formation of solid particles condensed from the cooling of hot nebular gas -> formation of planet-sized bodies by accretion of those solid particles. The Moon is supposed to have formed from the accretion of the relicts produced by the collision of proto-Earth with Mars-sized body. It is not easy to pinpoint the age of the Earth, considering the series of events related to the formation of the Earth. So, I propose that the collision age as that of the Earth, since the present status of the Earth is thought to be the direct product of the collision. According to the previous studies, the collision age can be broadly constrained between the age ($4567.30{\pm}0.16Ma$) of the earliest condensates (CAI, calcium-aluminum rich inclusion) of the nebula gas, i.e., the age of the solar system, and the oldest age ($4,456{\pm}40Ma$) among rocks and minerals of the Earth and the Moon. We need more precise estimation of the collision age, since it is important in estimating time scale for the formation of planet-size body and in revealing thermal evolution of magma oceans of the Earth and the Moon presumably developed right after the collision.

• The Journal of Internal Korean Medicine
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• v.23 no.1
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• pp.1-4
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• 2002

Objective : Hyperhomocysteinemia has been proven to be an independent risk factor for stroke. The genetic mutation of methylenetetrahydrofolate reductase(MTHFR) elevates serum homocysteine level, but it still remains controversial whether the MTHFR gene mutation could be a predictor of ischemic stroke. Therefore, we studied if this genetic defect could cause ischemic stroke independently. Methods : We gathered ischemic stroke subjects and age, sex-matched controls. Age, gender, past medical history, smoking habit, serum homocysteine level, and the MTHFR genotype were recorded. General characteristics of ischemic stroke subjects were compared to the controls. We classified the stroke according to the related vessels(small and large artery infarction) and single lesion and multiple infraction. Relevant risk of the MTHFR genotype was evaluated in each stroke subtype with multiple logistic regression analysis. Results : When the controls were compared to the whole ischemic stroke, there was no specific difference except some medical histories. However, further analysis based on stroke subtypes showed important results. The small artery infarction group, multiple infraction group had significant odds ratio of the MTHFR TT genotype adjusted for age, gender, medical history and smoking habit. Conclusions : The MTHFR TT genotype is an independent risk factor for certain types of ischemic stroke, small artery infarction and multiple infarction.

• Imaging Science in Dentistry
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• v.54 no.1
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• pp.71-80
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• 2024

Purpose: This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography. Materials and Methods: In total, 210 joints from 183 patients(144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model(α=0.05). Results: The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05). Conclusion: Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

• Korean Journal of Childcare and Education
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• v.15 no.3
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• pp.157-174
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• 2019

Objective: The purpose of this study was two-fold: first to explore the effects of mother-child attachment and effortful control at age 1 on preschoolers' school readiness at age 6, and second, to determine the mediating effect of a child's effortful control on the relationship between mother-child attachment at age 1 in relation to school readiness at age 6. Methods: Participants in this study were 205 five-year-old toddlers(106 boys, 99 girls) recruited for the Korea Child Panel Study. Mother-child attachment was assessed using the Attachment Q-sort(Waters, 1989). Preschooler's effortful control was measured by the Early Childhood Behavior Questionnaire: ECBQ(Putnam, Gartstein & Rothbart, 2006). Preschooler's school readness was measured by the School Readiness Scale Murphey & Burns, 2002). Data were analyzed using descriptive statistics, correlations, and the structural equation modeling analysis. Results: First, mother-child attachment at age 1 effected school readiness at age 6. Effortful control at age 1 effected school readiness at age 6. Second, effortful control at age 1 mediated the effect of mother-child attachment at age 1 in relation to school readiness at age 6. Conclusion/Implications: Mother-child attachment at age 1 affects school readiness at age 6, and toddlers' effortful control at age 1 mediates the relationship between mother-child attachment in relation to school readiness at age 6.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1185-1186
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• 2012

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.2
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• pp.201-206
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• 2019

Benign recurrent intrahepatic cholestasis (BRIC), a rare cause of cholestasis, is characterized by recurrent episodes of cholestasis without permanent liver damage. BRIC type 2 (BRIC2) is an autosomal recessive disorder caused by ABCB11 mutations. A 6-year-old girl had recurrent episodes of jaundice. At two months of age, jaundice and hepatosplenomegaly developed. Liver function tests showed cholestatic hepatitis. A liver biopsy revealed diffuse giant cell transformation, bile duct paucity, intracytoplasmic cholestasis, and periportal fibrosis. An ABCB11 gene study revealed novel compound heterozygous mutations, including c.2075+3A>G in IVS17 and p.R1221K. Liver function test results were normal at 12 months of age. At six years of age, steatorrhea, jaundice, and pruritus developed. Liver function tests improved following administration of phenylbutyrate and rifampicin. Her younger brother developed jaundice at two months of age and his genetic tests revealed the same mutations as his sister. This is the first report of BRIC2 confirmed by ABCB11 mutations in Korean siblings.

• Journal of Families and Better Life
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• v.28 no.1
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• pp.13-24
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• 2010

The purpose of this study were to examine the perception and behavior for preparing their old age. In order to achieve this purpose, a survey was conducted with 723 adults from Daegu and Kyungpook. Major findings of this study are as follow: First, there were statistically significantly different perception for preparing their old age according to the personal variables such as gender, age, education, marriage status, occupation and income. Second, there were statistically significantly different perception for preparing their old age according to the elderly-related variables such as taken the elder program, interests in media for elderly, the opinion on living together with the aged, contact with aged and the opinion about contact with aged. Third, there were statistically significantly different behavior for preparing their old age according to the personal variables such as gender, age, religion, education, marriage status, occupation and income. Finally, there were statistically significantly different behavior for preparing their old age according to the elderly-related variables such as taken the elder program, interests in media for elderly, the opinion on living together with the aged and the opinion about contact with aged.

• Journal of the Korean Society of Costume
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• v.22
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• pp.61-70
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• 1994

the purpose of study is to grasp the actual state of the textiles of Kojosun, Booyeo and Kogooryeo, by examining and studying about the excavated article of the textile of the Booyeo Age which was being gamered in the Research Institute of Study of antiquities of Civilization of gilimsung without being analyzed and examined after being excavated at September in 1990 and 1993, the textile of Kojosun Age wich was excavated and examined at East and North Gilimsung in China and the textile excavated and examined at the Kogooryeo grave at jiban China. 1. The kinds of textiles of Booye Age are warp kum plin weave silk plain weave bang gong Sa, and drawn and dyed textile, It is deemed that the real state of keum, Jeung and Hwi in the old literature of Sam guk Ji was grasped. 2. It emerges that more detailed wool than the wool fabric of China area of the same age was manufactured as the textile of Kojosun Age. hemp cloth corresponds to 12 Seung, in converting into fabric width of 50cm. 3. Keum was examined and reported as the textile of Kogooryeo Age and the real state of Woonkeum of Kogooryeo Age was grasped through "Wang ja moon keum" of Keumjang of mural of South and North I room of the grave that the same keum was excavated. The real state of dyed textile of hemp was grasped as the red hemp cloth was examined. Moreover the real state of development of advanced technique to weave with machine appeared by the grasp of inclination of loom with reed of Kogooryeo.Kogooryeo.

• Korean Journal of Childcare and Education
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• v.17 no.5
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• pp.43-61
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• 2021

Objective: This study aimed to examine the sequential mediating effects of children's perceived maternal acceptance and peer acceptance in the relationship between maternal warmth and first grade children's school adjustment. Methods: Participants in this study were 979 seven-year-old children(498 boys, 481 girls) recruited for the Korea Child Panel Study. Data were analyzed by analyzing descriptive statistics, correlations, and significance of serial mediation pathways using SPSS 18.0 and PROCESS Macro 3.4. Results: Maternal warmth at age five effected perception of maternal acceptance at age six. Perceived maternal acceptance at age six effected perceived peer acceptance at age six. Perceived peer acceptance at age six effected school adjustment at age seven. Lastly, perceived maternal acceptance and peer acceptance at age six had a serial mediation effect between maternal warmth at age five and school adjustment at age seven. Conclusion/Implications: Perceived social acceptance during preschool years should be emphasized in order to promote school adjustment for first grade children. Parent education for promoting better parent child relationships should be considered and teachers should encourage peer play interaction to help children perceive acceptance from their peers.

• Korean Journal of Health Education and Promotion
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• v.27 no.3
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• pp.13-22
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• 2010

Objectives: The aims of this study were to provide basic information on health behaviors of diabetics by age groups, compared to non-diabetics group. Methods: 2007 National Health Nutrition and Examination Survey Data were used to compare health behaviors between the diabetics group (191 diabetics who had been diagnosed by a doctor) and the non-diabetics group (382 general population) according to age groups. For the purpose of analysis, $x^2$-test (Fischer's exact test) and conditional logistic regression were used. Results: There were significant differences in health behaviors between the diabetics group and the non-diabetics group according to the history of health screening, BMI and alcohol consumption, and there were different pattern of health behaviors by age group. Conclusion: When developing and implementing health education and specific intervention programs for the correction of health behaviors among diabetics, one should consider age, age-adjusted health behavior patterns and priority.