• Economic and Environmental Geology
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• v.6 no.4
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• pp.201-216
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• 1973

Being believed thus far to be distributed in the wide areas in the vicinity of Seoul, the capital city of Korea, the Yonchon System in its type locality in Yonchon-gun from which the name derived was never previously traced down or correlated to the Precambrian metamorphic complex in Seoul area where the present study was carried out. Due to in accessibility to Yonchon area, the writer also could not trace the system down to the area studied so as to correlate them. The present study endeavored to differentiate general stratigraphy and interprete the structure of the metamorphic complex in the area. In spite of the complexity of structure and rapid changes in lithofacies of the complex, it was succeeded to find out the key bed by which the stratigraphy and structure of the area could be straightened out. The keybeds were the Buchon limestone bed in the western parts of the area; Daisongri quartzite bed cropped out in the southeastern area; Jangrak quartzite bed scattered in the several localities in the northwest, southwest, and eastern parts of the area; and Earn quartzite bed isolated in the eastern part of the area. These keybeds together with the broad regional structure made it possible to differentiated the Precambrian rocks in ascending order into the Kyonggi metamorphic complex, Jangrak group and Chunsung group which are in clinounconformable relation, and the first complex were again separated in ascending order into Buchon, Sihung, and Yangpyong metermorphic groups. Althcugh it has being vaguely called as the Yonchon system thus far, the Kyonggi metamorphic complex have never been studied before. The complex might, however, belong to early to early-middle Precambrian age. The Jangrak and Chunsung group were correlated to the Sangwon system in North Korea by the writer (1972), but it became apparent that the rocks of the groups have different lithology and highly metamorphosd than those of the Sangwon system which has thick sequence of limestone and slightly metamorphosed. Being deposited in the margin of the basin, it is natural that the groups poccess terrestrial sediments rather than limestone, yet no explanation is at hand as to what was the cause of bringing such difference in grade of metamorphism. Thus the writer attempted to correlate the both groups to those of pre-Sangwon and post-Yonchon which might be middle to early-late Precambrian time. Judging from difference in grade of deformation and unconformity between the Kyonggi metamorphic complex, Jangrak group, and Chunsung group, three stages of orogeny were established: the Kyonggi, Jangrak orogenies, and Chunsung disturbance toward younger age. It is rather astonishing to point out that the structure of these Precambrian formations. was not effected by Daebo orogeny of Jurassic age. The post-tectonic block faulting was accompanied by these orogenies, and in consequence NNE and N-S trending faults were originated. These faulting were intermittented and repeated until Daebo orogeny at which granites intruded along these faults. The manifestation of alignment of these faults is indicated by the parallel and straight linear development of valleys and streams in the Kyonggi Massifland.

• Journal of Environmental Health Sciences
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• v.48 no.6
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• pp.315-323
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• 2022

Background: Socioeconomical disadvantaged communities are more vulnerable to environmental chemical exposure and associated health effects. However, there is limited information on chemical exposure among vulnerable populations in Korea. Objectives: This study investigated chemical exposure among underprivileged populations. We measured urinary metabolites of phthalates in urban disadvantaged communities and investigated their correlations with residential environment factors and relative socioeconomic vulnerability. Methods: Urine samples were collected from 64 residents in a disadvantaged community in Seoul. A total of eight phthalate metabolites were analyzed by liquid chromatography-mass spectroscopy. Analytical method used by the Korean National Environmental Health Survey (KoNEHS) was employed. Covariate variance analysis and general linear regression adjusted with age, sex and smoking were performed. Results: Several phthalate metabolites, namely monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-n-butyl phthalate (MnBP) had higher levels than those reported in the adults of 4th KoNEHS. Notably, the MnBP level was higher in the lower socioeconomic group (geometric mean [GM]=47.3 ㎍/g creatinine) compared to non-recipients (GM=31.9 ㎍/g creatinine) and the national reference level (GM=22.0, 28.2 and 32.2 ㎍/g creatinine for adults, 60's and 70's, respectively.). When age, sex and smoking were adjusted, MEP and MnBP were significantly increased the lower socioeconomic group than non-recipients (p=0.014, p=0.023). The lower socioeconomic group's age of flooring were higher than non-recipients, not statistically significant. Conclusions: These results suggest that a relatively low income and aged flooring could be considered as risk factors for increased levels of phthalate metabolites in socioeconomic vulnerable populations.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.357-365
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• 2019

Purposes: This study aimed to investigate the differences in the health-related quality of life (EQ-5D) in Korean adults according to gender, age period, and the metabolic syndrome or not. Methods: The study subjects were 5,021 adults, who completed all of the KNHANES VI-2. The subjects were categorized, using life periods, into young, middle-aged, and older adults. Methods were selected based on the KNHANES VI-2. IBM SPSS 25.0 was used for a complex samples cross-tabulation, general linear model and a complex samples t-test. Results: The HRQoL (EQ-5D) was higher in male(p<.001), in the young group by age(p<.001), and in the non-metabolic syndrome group(p>.05). In condition of the metabolic syndrome by gender, the female group's EQ-5D was higher in the non-metabolic syndrome group; there was the result of the complex samples independent t-test revealed significant differences in EQ-5D(p<.01). Conclusion: The HRQoL (EQ-5D) was higher in male, young, and in the non-metabolic syndrome group. Also, in condition of metabolic syndrome in female, there was the result of the complex samples independent t-test revealed significant differences in EQ-5D.

• Journal of Life Science
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• v.24 no.8
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• pp.895-902
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• 2014

Adiponectin has been known to improve insulin sensitivity and elicit glucose uptake via increased glucose transporter 4 (GLUT4) translocation. In the current study, mRNA expression levels of adiponectin and GLUT4 were measured in subcutaneous adipose tissue from C57BL/6 mice fed normal (ND) or high-fat diet (HFD) until 16, 26, 36, 47, or 77 weeks of age starting from 6 weeks of age. Expression levels were also measured in mice with calorie restriction (CR) and in thiazolidinedione (TZD) treated mice. Using quantitative real-time PCR, we demonstrated that GLUT4 expression in adipose tissue significantly decreased in HFD mice groups and increased in CR (p<0.05) and TZD (p=0.007) groups while there was no difference in adiponectin mRNA expression levels between experimental and control groups. General linear regression models were used to assess the association of gene expression levels between adiponectin and GLUT4 and to determine whether adiponectin affects GLUT4 transcription. mRNA expression levels of adiponectin and GLUT4 are significantly associated each other in mice fed a ND (p<0.0001) or HFD (p<0.0001), in groups separated into each age and diet, and CR group (p=0.002), but not in TZD group (p=0.73). These results demonstrated that gene expression of adiponectin and GLUT4 is strongly associated, suggesting that there is a common regulatory mechanism for adiponectin and GLUT4 gene expression and/or adiponectin has a direct role in GLUT4 gene expression in adipose tissue.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.4
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• pp.492-505
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• 2007

Statement of problem: An orthodontic miniscrew implant has been used as a skeletal anchorage for orthodontic treatment. However, any relation among the influence of the cortical bone, morphologic differences of orthodontic miniscrew implants and new bone formation hasn't been made clear yet. Purpose: The purpose of this study was to evaluate whether the orthodontic miniscrew implant could work as an intraoral skeletal anchorage immediately and stably for orthodontic treatment after insertion of it. Material and methods: Two types of orthodontic miniscrew implants were used in this experiment; tapered type and straight type. One hundred and sixty eight orthodontic miniscrew implants were inserted into the tibiae of 21 rabbits and sacrificed on 3, 7, 11, 14, 21 and 28days later after insertion of them to study removal torque values and histologic and histomorphometric analyses. Results: The results were as follows. 1. The removal torque values of the tapered type were higher than those of the straight type in all groups(p<0.05). 2. There wasn't any distinguishing differences between the tapered type and the straight type about the new bone formation percentage. 3. The removal torque values for both the tapered type and the straight type were gradually decreased at early stages of the test but started to increase at the 7 days group of the straight type and the 11 days group of the tapered type. 4. New bone formation percentage was increased gradually for both the tapered and the straight types as time passed(p<0.05). 5. It was found that the tapered type showed lower values in the cortical bone about both the maximum equilibratory stress distribution and the maximum principal stress distribution than the straight type in linear finite elements analysis. Conclusion: According to the research, the removal torque values were decreased at 7 days group of the tapered type and 11 days group of the straight type after the insertion of the orthodontic miniscrew implants in tibiae of rabbits. Considering the human bone activity, it is better to apply the orthodontic force $3{\sim}4$ weeks later than to apply it immediately after the insertion of orthodontic miniscrew implants. Considering that general orthodontic force is about $250{\sim}500$ grams, the tapered type can be worked as a stable skeletal anchor age in an orthodontic treatment even if the orthodontic force is applied on it immediately after the insertion of it.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.387-397
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• 2015

In this paper, the determinants of the number of job changes in the SMEs (small and medium enterprises) youth-intern project is analysed, utilizing SMEs youth-intern DB and employment insurance DB. Since the number of job changes are count data which take integer values other than negative values, general linear regression analysis becomes inappropriate. Therefore, four models such as Poisson regression model, zero inflated Poisson regression model, negative binomial regression model and zero inflated negative binomial regression model are tried to fit count data. A zero inflated negative binomial regression model is selected to be the best model. Major results are the followings. First, the number of job changes is shown to be significantly smaller in the treatment group than in the control group. Second, the number of job changes turns out to be significantly smaller in the young-age group than in the old-age group. Third, it is also shown that the number of job changes of man is significantly greater than that of woman. Lastly, the number of job changes in the bigger firm is shown to be significantly less than that of the smaller firm.

• Journal of agricultural medicine and community health
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• v.39 no.3
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• pp.176-186
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• 2014

Objectives: As a sequel to the former analysis of the quality of life (QoL) among young-old and old-old in Korea, this research was aimed to identify factors related to the quality of life and the gender difference after controlling for the related factors among Korean elderly. Methods: Selected elderly data of 1,339 subjects from the 5th Korea National Health and Nutrition Examination Survey conducted in 2010 was analyzed. In this survey, QoL was measured using Euro Quality of Life (EQ-5D) instrument. Data were analyzed using complex survey data analysis on IBM-SPSS 20.0. The related factors were identified using general linear models with backward elimination. The gender difference was tested also using general linear models. Results: The distributions of educational level, family income level, and presence of cohabitant were different between male and female elderly in both young-old and old-old age group. So were the health behaviors and perceived health, and experience of stress, depression, and suicidal thoughts. QoL and its subscales- mobility, self care, daily living, pain and discomfort, and anxiety and depression- were consistently better among male elderly regardless of age group. Among the variables considered, education, family income level, presence of cohabitant, perceived health, age group and BMI were found to be related to the QoL at p=.05, and presence of chronic diseases at p=.10. The difference in QoL between male and female elderly after controlling for the variables was statistically significant. Conclusion: Improving QoL is particularly important for the elderly. In order to improve QoL of the elderly, age- and gender- differences need to be considered when developing services and programs for the elderly.

• Journal of Preventive Medicine and Public Health
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• v.25 no.3 s.39
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• pp.247-268
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• 1992

This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.122-122
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• 2003

This study examined the viability of canine oocytes following storage at 4 or $38{\circ}C$ for 5 hrs. The ovaries were collected from domestic dog following ovariohysterectomy at a local veterinary clinics and transported to laboratory In two different transport temperature at 4 or $38{\circ}C$ within 5 hrs. The cumulus oocyte complexes (COCs) were recovered after slicing with blade. In Exp. 1, the oocytes collected were matured in DMEM supplemented with l0% FBS, 0.6 mM/mlcysteine, 0.2 mM Pyruvic acid, 20 ng/ml $E_2$ and 1 $\mu g/ml$ rbST at humidified atmosphere containing 5% $CO_2 38{\circ}C$ for 24 or 48 hrs to analysis of survivability. In Exp 2, to assess nuclear development at 38{\circ}C$ group, the oocytes were matured in maturation medium for 24, 48 or 96 hrs. Survivability was judged by a morphological appearance and PI staining. Survivability rates were analyzed by General Linear Models procedure in SAS. The survival rates at 4{\circ}C$ ovary transport group showed significantly lower than at 38{\circ}C$ group (0 vs 72.9% in 48 hrs and 13.2 vs 77 8% in 24 hrs; P<0.05). The nuclear development of oocytes to MI to MII stages at 24, 48 and 96 hrs was 8.3% (6/72), 8.9% (9/101), and 9.5% (8/84). These results showed that the canine oocytes were remarkably sensitive to a low temperature and did not increase nuclear development rate depend on maturation time to 96 hrs.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.830-837
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• 2007

Background and purpose : Stroke is one of the most deadly diseases and a leading cause of disability. Lipids confer an increased risk for cardiovascular morbidity and mortality. In spite of many studies on the relationship between stroke and lipids, their relationship is not clear. This study was undertaken to determine whether lipids were associated with stroke. Method : We compared the components of blood lipids between stroke patients group (n=217,Cases), non-stroke control group (n=160, Controls) and healthy control group without hypertension, diabetes mellitus, ischemic heart disease, or hyperlipidemia (n=140, Normals). These data were statically analyzed by general linear models and binary logistic regression analysis to get each adjusted odds ratio. Result : The results were as follows. The blood levels of total cholesterol (T-Chol), triglyceride (TG) and low density lipoprotein cholesterol (LDL-Chol) were significantly higher in patients of ischemic stroke, while the blood levels of T-Chol and LDL-Chol were significantly lower, and the blood levels of TG significantly higher in patients of hemorrhagic stroke. The blood level of high density lipoprotein cholesterol (HDL-Chol) was significantly lower in all cases. Conclusion : These results suggest that high TG and low HDL-Chol may be risk factors of hemorrhagic stroke and ischemic stroke, high T-Chol and LDL-Chol may be risk factors of ischemic stroke, and low T-Chol and LDL-Chol may be risk factors of hemorrhagic stroke in Koreans.