• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.5.1-5.14
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• 2023

Background: Perfluoroalkyl substances (PFAS) are chemicals widely used in various products in everyday life. Due to its unique strong binding force, the half-life of PFAS is very long, so bioaccumulation and toxicity to the human body are long-standing concerns. In particular, effects on kidney function have recently emerged and there are no studies on the effect of PFAS on kidney function through epidemiological investigations in Korea. From 2018 to 2020, the Korean National Environmental Health Survey (KoNEHS) cycle 4, conducted an epidemiological investigation on the blood concentration of PFAS for the first time in Korea. Based on this data, the relationship between PFAS blood concentration and kidney function was analyzed for adolescents. Methods: We investigated 5 types of PFAS and their total blood concentration in 811 middle and high school students, living in Korea and included in KoNEHS cycle 4, and tried to find changes in kidney function in relation to PFAS concentration. After dividing the concentration of each of the 5 PFAS and the total concentration into quartiles, multivariable linear regression was performed to assess the correlation with kidney function. The bedside Schwartz equation was used as an indicator of kidney function. Results: As a result of multivariable linear regression, when observing a change in kidney function according to the increase in the concentration of each of the 5 PFAS and their total, a significant decrease in kidney function was confirmed in some or all quartiles. Conclusions: In this cross-sectional study of Korean adolescents based on KoNEHS data, a negative correlation between serum PFAS concentration and kidney function was found. A well-designed longitudinal study and continuous follow-up are necessary.

• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.51-72
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• 1999

In orthodontic field, it is very important to understand the normal growth. Such an understanding can be derived from observation of normal growth in various samples from childhood to adulthood, and this builds a foundation from which growth abnormality or variation can be defined. Thus, a broad data collection of normal children, as well as basic study reviewing such data become necessary. The relationship between the mean values of cephalometric measurements in Growth and Development was studied among the groups(boys and girls) of Korean chidren from the ages 6-years to 16-years. 220 boys 170 girls were chosen as subjects : Cephalometric X-ray were taken for 3 years and hard tissue analysis on McNamara and Ricketts Analysis which was divided into measurements of 5 parts(Cranial base, Cranial base and Maxilla & Mandible, Maxilla and Mandible, Mandible, Dental measurements). The relationship of craniofacial growth was studied. The following conclusions were obtained: 1. There were statistically significant differences in anterior cranial base between the two sexes of 14 and 15-year grouips. 2. In comparison of growth amounts among different age groups, statistically singnificant difference in Posterior facial height exhisted among $10\~11,\;12\~13\;and\;14\~15$ year-old interval groups. This pattern increased with aging. 3. Na perpendicular to A showed earlier growth peak in females(11-12years) than males(12-13years). When horizontal measurements of point A and Pogonion are compared, mandibular growth appeared to be greater. 4. Maximum growth peak of cranial base and mandible was earlier in females (11-12years) than males(13-14 years). 5. Upper central incisor flared out with aging, and there were increases in lower incisor to A-Pg, and lower incisor inclination There was significant difference between the two sexes in 10-year-old group.

• Journal of The Korean Association For Science Education
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• v.35 no.5
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• pp.841-856
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• 2015

This study sought to explore longitudinal changes in Korean fourth graders' career aspirations in science. The sample included those who had high interest, but low career aspirations in science, and the analysis focused on the concept of science identity. To achieve this study's objectives, we selected 14 participants and then conducted two in-depth interviews with them. Compared with the first interviews (4th grade), changes were observed in eight students' career aspirations in science in the second round (5th grade). While six students maintained "negative" career aspiration, six revealed "medium" and two revealed "positive" career aspiration in science. To explore the relationship between science identities and career aspirations in science, three students were selected from the sample for further study. According to the results, the aspects of science identity that students valued regarding potential careers varied individually. Depending on these aspects, each student showed different patterns in the interactions between different aspects of science identity, and between aspects of science identity and science-related career aspirations. Over time, participants' experiences and interactions with people around them produced changes in their science identity, which led to changes in their career aspirations resulting from the interactions between aspects of their science identity. Their career aspirations in science were also significantly influenced by each participant's perceptions of relationships with peers (i.e., recognition by peers and of peers) and of science-related careers. Therefore, the results suggest that students need to be provided with appropriate learning environments and guidance relating to science careers.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.9 no.1
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• pp.54-66
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• 1998

Objectives：This study was to investigate the impact of parental psychiatric disorder on offspring's depression, anxiety, self concept, perception of familial relationship compared with offspring of normal control. In offsprings of parents with psychiatric disorder, this study explored whether their psychopathology, self concept, and perception of familial relationship were influenced by parent’s sex, onset time of parent’s psychiatric disorder and parent’s psychiatric diagnosis. Methods：52 offsprings aged 10-18 years of 39 psychiatric outpatient were surveyed from June, 1997 to April, 1998 and completed several questionnaaire, including Korean from of the Family Environment Scale, Korean form of the State-Trait Anxiety Inventory for Children, Korean form of Kovac’s Children’s Depression Inventory, and Korean form of Piers-Harris Children’s Self-Concept Scale. Their score was compared with offsprings’ of normals. In offsprings of parents with psychiatric disorder, they were compared according to parent’s sex, onset time of parent's psychiatric disorder and parent’s psychiatric diagnosis. Results：The results were as follows：1) Offsprings of parents with psychiatric disorder reported higher level of state anxiety and lower level of the FES expressive subscale than offsprings of normals(p<0.05). But they reported higher level of PHCSCS intellectual & school status subscale and popularity subscale than normals(p<0.05). 2) There were no differences in anxiety, depression, self concept, and perception of familial relationship between patient’s sex. 3) Offsprings less than 3 years old when parent’s psychiatric disorder had developed showed higher level of trait anxiety and lower level of FES control subscale than offsprings more than 3 years old (p<0.05). 4) There were no diferences in anxiety, depression, self concept, and perception of familial relationship between patient’ diagnostic groups(schizophrenia spectrum disorder-mood disoderneurosis). Conclusion：The finding indicated that self reported scale of anxiety and depression showed no significant difference between offsprings of psychiatric patients and offsprings of normals. In offsprings of parents with psychiatric disorder, parent’s sex and psychiatiric diagnosis had no influence on offspring’s psychopathology. But the offspring’s age(before 3 years old) when the parent’s psychiatriric disorder developed had influence on higher level of offspring’s trait anxiety. For further high risk group study, direct interview and evaluation of parent-child agreement or teacher-child agreement will be needed in longitudinal study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.349-357
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• 2020

This study aimed to examine the effects of self-rated health on life satisfaction among Korean babyboomers and to address the mediating effect of depression on the self-rated health-life satisfaction relationship. Further, this study attempted to identify any relationship between self-rated health, depression, and life satisfaction among babyboomers according to work status. Researchers conducted a secondary data analysis using the 6th wave of the Korean Longitudinal Study on Aging. The final sample was 2,479 babyboomers born between 1955 and 1963. Testing the mediating effect of depression was done by the significance of direct, indirect, and total effects. Researchers also compared an unconstrained model with constrained model for multiple group analysis. Results indicate that self-rated health was a significant factor in determining the life satisfaction of babyboomers. In addition, depression had a significant mediating effect on the self-rated health and life satisfaction of babyboomers. Multiple group analysis demonstrated, in the non-working babyboomer model, the effects of self-rated health and depression on life satisfaction, and the effect of depression on life satisfaction was stronger than that of the working babyboomer model. The results of this study have established the importance of health and working status in addressing depression and life satisfaction among babyboomers.

• Management & Information Systems Review
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• v.17
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• pp.107-133
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• 2005

The purpose of this study was to analyze a trend of profitability classified by characteristics of hospitals and to analyze related factors. The data for this study were derived from survey material conducted by the Korean Hospital Association on 33 hospitals in Korea between 1993 and 2002. Profitability was measured in the aspect of investment profit rate and operation profit rate with net profit to total assets, normal profit to total assets and operating margin to gross revenue as dependent variables. Independent variables were classified by general factors (ownership, number of beds, period of establishment, region), financial factors (total asset turnover, liabilities to total assets, current ratio, fixed ratio, inventories turnover, personnel costs per operation profit, material costs per operation profits), composition of manpower and facilities(personnel and area per beds), productivity index(the number of daily patients per medical doctor, the number of daily patients per nurse), the score of quality assurance activities. First, Concerning the specialists per beds or area per beds and profitability of hospitals there was not statistically significant. Second, Those hospitals having the most daily patients per nurse had significantly higher profitability than the others, but the number of daily patients per medical doctor had little effect on the profitability. Thirds, Those hospitals having a higher proportion total asset turnover tended to show significantly higher profitability compared to other hospitals, but the liabilities to total assets and liquidity ratio had a little difference to the profitability. Those hospitals having a higher proportion personnel costs per operation profit and material costs per operation profits tended to show significantly lower hospital profitability compared to other hospitals. Fourth, In regression analysis, hospital profitability had negative relationship with personnel costs per operation profit or material costs per operation profits. While it had positive relationship with total asset turnover, the number of daily patients per nurse. In conclusion, private hospitals had higher profitability than that of public hospitals. Though factors related to profitability of hospital were different according to ownership, it is important for securing appropriate profitability by operating appropriate number of nurse, raising total asset turnover, and reducing personnel costs, material costs per operation profits. This study can be used as a baseline data for planning of hospital management. But the study may be limited in that the results cannot be generalized due to its small sample size. However, this longitudinal observation of 33 hospitals over ten year period has significant merit alone.

• Journal of Preventive Medicine and Public Health
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• v.49 no.4
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• pp.220-229
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• 2016

Objectives: The association between educational status and 10-year risk for acute coronary syndrome (ACS) and all-cause mortality was evaluated. Methods: From October 2003 to September 2004, 2172 consecutive ACS patients from six Greek hospitals were enrolled. In 2013 to 2014, a 10-year follow-up (2004-2014) assessment was performed for 1918 participants (participation rate, 88%). Each patient's educational status was classified as low (<9 years of school), intermediate (9 to 14 years), or high (>14 years). Results: Overall all-cause mortality was almost twofold higher in the low-education group than in the intermediate-education and high-education groups (40% vs. 22% and 19%, respectively, p<0.001). Additionally, 10-year recurrent ACS events (fatal and non-fatal) were more common in the low-education group than in the intermediate-education and high-education groups (42% vs. 30% and 35%, p<0.001), and no interactions between sex and education on the investigated outcomes were observed. Moreover, patients in the high-education group were more physically active, had a better financial status, and were less likely to have hypertension, diabetes, or ACS than the participants with the least education (p<0.001); however, when those characteristics and lifestyle habits were accounted for, no moderating effects regarding the relationship of educational status with all-cause mortality and ACS events were observed. Conclusions: A U-shaped association may be proposed for the relationship between ACS prognosis and educational status, with participants in the low-education and high-education groups being negatively affected by other factors (e.g., job stress, depression, or loneliness). Public health policies should be aimed at specific social groups to reduce the overall burden of cardiovascular disease morbidity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.646-652
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• 2017

The objective of this study was to verify the longitudinal reciprocal causal relationship between depression and the somatic symptoms of depression among adolescents through an autoregressive cross-lagged model using data from the Korean Children & Youth Panel Survey. The subjects of this study included 1,968 adolescents, who participated in the second, fourth, and sixth Korean Children & Youth Panel Surveys. The results showed that both depression and the somatic symptoms of depression at a previous point in time affect depression and the somatic symptoms of depression at a later point in time. It was also found that depression at a previous point in time has a cross-lagged effect on the somatic symptoms of depression at a later point in time, implying that more severe depression at a previous point in time leads to increased severity of somatic symptoms at a later point in time. It was found that the somatic symptoms of depression at a previous point in time have a cross-lagged effect on depression at a later point in time, indicating that more severe somatic symptoms of depression at a previous point in time lead to increased severity of depression at a later point in time. This study is significant in that it provides baseline information about nursing interventions for adolescent mental health.

• Korea journal of population studies
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• v.35 no.1
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• pp.211-238
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• 2012

Using data from Korean Longitudinal Study on Aging (KLoSA), this study examines how continuity and change of marital status is associated with health over time among older women, focusing on the moderating effects of age and parent-child relationships. KLoSA data set has two waves of interviews, and for this study, 2046 women aged 65 and over were selected. To analyze data, Structural Equation Modeling (SEM) was used. The major findings are as follows. First, there was no statistically significant difference in health between continuously married older women and continuously single older women. However, older women who had transition from being married to being single showed lower physical health than continuously married and continuously single older women. Second, there were statistically significant differences in the effect of marital status on mental health according to the age of older women. Older women who had transition from being married to being single showed lower mental health than continuously married elders when older women were younger. Third, contact with children moderated the effect of marital status on physical health. Older women who had transition from being married to being single showed lower physical health than continuously single and continuously married older women when older women had less contact with their children. The findings imply after the loss of marital role, older women's relationship with adult children plays a significant role in promoting health. In conclusion, the findings of this study show the different pathways through which marital status is associated with health for 3 different groups of older women, being continuously single, being continuously married, and making transition from being married to being single.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.365-371
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• 2007

To evaluate the effect of air pollution on respiratory health in children, We conducted a longitudinal study in which children were asked to record their daily levels of Peak Expiratory Flow Rate(PEFR) using potable peak flow meter(mini-Wright) for 4 weeks. The relationship between daily PEFR and ambient air particle levels was analyzed using a mixed linear regression models including gender, age in year, weight, the presence of respiratory symptoms, and relative humidity as an extraneous variable. The daily mean concentrations of $PM_{10}$ and $PM_{2.5}$ over the study period were $64.9{\mu}g/m^3$ and $46.1{\mu}g/m^3$, respectively. The range of daily measured PEFR in this study was $182{\sim}481\;l/min$. Daily mean PEFR was regressed with the 24-hour average $PM_{10}(or\;PM_{2.5})$ levels, weather information such as air temperature and relative humidity, and individual characteristics including sex, weight, and respiratory symptoms. The analysis showed that the increase of air particle concentrations was negatively associated with the variability in PEFR. We estimated that the IQR increment of $PM_{10}$ or $PM_{2.5}$ were associated with 1.5 l/min (95% Confidence intervals -3.1, 0.1) and 0.8 l/min(95% CI -1.8, 0.1) decline in PEFR. Even though this study showed negative findings on the relationship between respiratory function and air particles, it was worth noting that the findings must be interpreted cautiously because exposure measurement based on monitoring of ambient air likely resulted in misclassification of true exposure levels and this was the first Korean study that $PM_{2.5}$ measurement was applied as an index of air quality.