• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.3
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• pp.245-256
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• 2017

Objectives: The present study is aimed at performing real-time measurement of fibrous materials using an F-1 fiber monitor, investigating the correlations between the measurements and environmental conditions, and assessing the feasibility of the use of the monitor in actual exposure assessments based on the accuracy and reliability of the device. Methods: Asbestos specimens with a fixed asbestos content were dispersed in a chamber and collected with a particle measuring test device. Measurements obtained by the existing PCM method, and with the F-1 fiber monitor were compared. In addition, concentrations of asbestos fibers obtained by the PCM method, the TEM method, and the F-1 fiber monitor were compared with that of specific ABS scenarios in NOA regions. Correlations of asbestos contents in soil and weather conditions with each method of measurement were analyzed. Results: Laboratory results showed that levels of asbestos fibers measured with each method increased as fiber contents in soil increased. In the accuracy and reproducibility assessment, no significant differences were found between the different methods of measurement. On-site assessment results showed positive correlations among the methods, and these correlations were less significant compared with what was shown by the laboratory results. Levels of asbestos fibers increased as asbestos contents in soil increased, and as temperature increased. Levels of asbestos fibers decreased as humidity increased, and wind speed did not significantly affect the extent to which asbestos fibers were scattered. Conclusions: While it would be premature to replace existing methods with the use of F-1 fiber monitors in real sites based on the results of this study, the monitor may be useful in the screening of the sites, which assesses hazard levels in different regions. Replacement of existing methods with the use of F-1 fiber monitors may be possible after the limitations identified in this study are overcome, and additional assessment data are obtained and reviewed under different conditions to confirm the reliability of the monitor in future research. Obtained assessment results may be used as basic data for the assessment of asbestos hazard in NOA regions.

• Journal of Preventive Medicine and Public Health
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• v.42 no.4
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• pp.251-260
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• 2009

Objectives : To estimate the annual socioeconomic costs of stroke in Korea in 2005 from a societal perspective. Methods : We identified those 20 years or older who had at least one national health insurance (NHI) claims record with a primary or a secondary diagnosis of stroke (ICD-10 codes: I60-I69, G45) in 2005. Direct medical costs of the stroke were measured from the NHI claims records. Direct non-medical costs were estimated as transportation costs incurred when visiting the hospitals. Indirect costs were defined as patients and caregivers productivity loss associated with office visits or hospitalization. Also, the costs of productivity loss due to premature death from stroke were calculated. Results : A total of 882,143 stroke patients were identified with prevalence for treatment of stroke at 2.44%. The total cost for the treatment of stroke in the nation was estimated to be 3,737 billion Korean won (KRW) which included direct costs at 1,130 billion KRW and indirect costs at 2,606 billion KRW. The per-capita cost of stroke was 3 million KRW for men and 2 million KRW for women. The total national spending for hemorrhagic and ischemic stroke was 1,323 billion KRW and 1,553 billion KRW, respectively, which together consisted of 77.0% of the total cost for stroke. Costs per patient for hemorrhagic and ischemic stroke were estimated at 6 million KRW and 2 million KRW, respectively. Conclusions : Stroke is a leading public health problem in Korea in terms of the economic burden. The indirect costs were identified as the largest component of the overall cost.

• Journal of Life Science
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• v.29 no.12
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• pp.1321-1328
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• 2019

Intermediate-wavelength solar radiation, also known as ultraviolet B (UVB: 290-320 nm) radiation, may cause premature aging and oxidative damage-dependent skin cancer in humans. UVB-induced formation of reactive oxygen species (ROS)-often a consequence of excessive exposure to these rays-could activate matrix metalloproteinases (MMPs) such as MMP-1 and MMP-3. These enzymes break down type I collagen in human fibroblasts. In this study, we assessed the antioxidant and anti-aging effects of ethyl acetate extract of blueberry (EEB). An antioxidant test in blueberries evaluated ROS production using CCD-986sk cells and DPPH assay. In order to evaluate the anti-wrinkle efficacy of blueberries, the MMP-1 production and type 1 procollagen synthesis evaluated and the expression of MMP 1, 3 were tested through Western blot and RT- PCR. EEB exhibited 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reduced the production of UVB-induced ROS. Also, EEB inhibited UVB-induced processes associated with photoaging and skin cancer, such as reduction in procollagen production and increase in MMP-1 production. More precisely, EEB (50 ㎍/ml) markedly suppressed mRNA and protein levels of MMP-1 and -3. The anti-aging effects are attributable to the antioxidant activity of EEB. These findings indicate that EEB has a protective effect against UVB-induced aging in human fibroblast cells by regulating the levels of type-1 procollagen, MMP-1, and MMP-3.

• Communications of Mathematical Education
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• v.24 no.2
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• pp.385-413
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• 2010

The purpose of this study is to set appropriate targets for school-year levels and types of mathematical communication. First, I classify mathematical communication into four types as Discourse, Representation, Operation and Complex and refer to them collectively as the 'D.R.O.C pattern'. I have listed achievement factors based on the D.R.O.C pattern hearing opinions from specialists to set a target, then set a final target after a 2nd survey with specialists and teachers. I have set targets for mathematical communication in elementary schools suitable to its status and students' levels in our country. In NCTM(2000), standards of communication were presented only from kindergarten to 12th grade students, and, for four separate grade bands(prekindergarten through grade 2, grades 3-5, grades 6-8, grades 9-12), they presented characteristics of the same age group through analysis of classes where communication was active and the stated roles of teachers were suitable to the characteristics of each school year. In this study, in order to make the findings accessible to teachers in the field, I have classified types into Discourse, Representation, Operation and Complex (D.R.O.C Pattern) according to method of delivery, and presented achievement factors in detail for low, middle and high grades within each type. Though it may be premature to set firm targets and achievement factors for each school year group, we hope to raise the possibility of applying them in the field by presenting targets and achievement factors in detail for mathematical communication.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.152-159
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• 2017

Purpose: X-linked agammaglobulinemia (XLA) is a primary immunodeficiency caused by mutations in the Bruton's tyrosine kinase (Btk) gene. The aim of this study was to investigate the clinical manifestations, molecular features, and treatment status of XLA in Korean patients at Seoul National University Children's Hospital. Methods: Fourteen Korean boys with XLA showing serum agammaglobulinemia, non-detectable to less than 2% of peripheral B-cells, and mutation of the Btk gene were enrolled. We observed the clinical features, laboratory findings, status of treatment, and complications in these XLA patients. Results: All XLA patients had a history of recurrent bacterial infections before diagnosis, and 20% of them had a neutropenia. Of the XLA patients 35.7% had a family history of XLA and 75% of their mothers were carriers. Btk gene analysis showed variable gene mutations in Xq22 including 9 amino acid substitutions, 3 frameshifts, 1 premature stop codon, and 1 splice defect. After intravenous immunoglobulin replacement therapy, infection episodes decreased, but complications such as bronchiectasis and chronic sinusitis remained. Conclusions: In patients less than 4 years of age with recurrent infection, analysis of serum gamma globulin levels and the Btk gene are recommended for the early diagnosis of XLA and for the appropriate prevention of recurrent infection.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.1-12
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• 2002

Objective : To estimate the socioeconomic costs of obesity in Korea,1998. Methods : The 1998 National Health and Nutrition Examination Survey(1998 NHNES) data was used and 10,880 persons who had taken health examinations were selected for study. Essential hypertension, NIDDM(non insulin-dependent diabetes mellitus), dyslipidemia, osteoarthritis, coronary heart disease, stroke were included as obesity related disease. The data of direct costs of obesity was obtained from the National Federation of Medical Insurance. The category of indirect costs was the loss of productivity caused by premature death and admission, time costs, traffic costs, nursing fees due to obesity. Multiple logistic regression model was developed to estimate prevalence odds ratio by obesity class adjusted demographic and socio-ecnomic factors and calculate PAF(Population Attributable Fraction) of obesity on obesity related disease. And we finally calculated the socioeconomic costs of obesity in relation to BMI with PAF. Results : The direct costs of obesity were 2,126 billion${\sim}965$ billion Won in considering out of pocket payment to uninsured services, and the indirect costs of obesity were 2,099 billion${\sim}1,086$ billion Won. Consequently, in considering out of pocket payment to uninsured services, the socioeconomic costs of obesity were 4.225 billion${\sim}2,050$ billion Won, which corresponded to about $0.094%{\sim}0.046%$ of GDP and $1.88%{\sim}0.91$ of total health care costs in Korea. Conclusions : Obesity represents a major health problem with significant economic implications for the society. This results are conservative estimates as far as all obesity related disease and all health care and indirect costs were not included due to missing information. further studies are needed to caculate socioeconomic costs of obesity more exactly.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.117-124
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• 2003

Objectives : This study was performed to examine the relationship between maternal exposure to environmental tobacco smoke (ETS) and pregnancy outcomes (low birth weight or preform baby) in a prospective cohort study. Methods : We made a pregnant women's cohort, and followed the pregnancy outcomes, between May 1st 2001 and August 31st 2002. We surveyed 2,250 women who visited our hospital during their 35th gestational week, with a self-administered questionnaire. The final total of mother-infant pairs analyzed in this study was 1,712. We used a multiple logistic regression analysis to analyze the effect of maternal ETS on the incidence of preform or low birth weight, and a linear regression analysis for the birth weight and gestational age. Results : Higher exposure to ETS (>=1 hours/day) during pregnancy was more negatively associated with the gestational age and birth weight, than no exposure to ETS (no or less than 1 hour). Maternal exposure to ETS was associated with preform baby(adjusted odds ratio (AOR) 1.7; 95% confidence interval (CI) 0.9, 3.3) and low birth weight (AOR 2.3; 95% CI 0.9, 5.5). In addition, we found that maternal ETS may reduce the birth weight by 70g after adjusting for potential confounding factors. Conclusions : This study suggests that maternal exposure to ETS during pregnancy may increase the frequency of low birth weights and preform births.

• Journal of Korean Society of Steel Construction
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• v.14 no.4
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• pp.557-566
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• 2002

This paper summarized the results of a full-scale cyclic seismic testing on four reduced beam section (RBS) steel moment connections. Specifically, these tests addressed a bolted web versus a welded web connection and strong versus medium panel zone (PZ) strength as key test variables. Specimens with medium PZ strength were designed to promote balanced energy dissipation from both PZ and RBS regions, in order to reduce the requirement for expensive doubler plates. Both strong and medium PZ specimens with welded web connection were able to provide sufficient connection rotation capacity required of special moment-resisting frames. On the other hand, specimens with bolted web connection performed poorly due to premature brittle fracture of the beam flange at the weld access hole. Unlike the case of web-welded specimens, specimens with cheaper bolted web connection could not transfer the actual plastic moment of the original (or unreduced) beam section to the column. No fracture occurred within the beam groove welds of any connection in this testing program. If fracture within the beam flange groove weld is avoided by using quality welding procedure as in this study, the fracture issue tends to move into the beam flange base metal at the weld access hole. Supporting analytical study was also conducted in order to understand the observed base metal fracture from the engineering mechanics perspective.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.59-67
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• 2000

This study was investigated the developmental potential of bovine embryos following nuclear transfer with bovine fetal fibroblasts (BFF). BFF were isolated from a male 45-day-old-fetus. Non-starved BFF labeled with MitoTracker were transferred into perivitelline space of enucleated oocytes. BFF-oocyte units were fused by electric pulse, and then fused oocytes were activated with calcium ionophore A23187 and subsequently 6-dimethylaminopurine (6-DMAP). The resulting zygotes were placed into CRlaa bovine embryo culture medium. Transfer of the nucleus into enucleated oocyte led to premature chromosome condensation, swelling and pronucleus formation. Remodeled oocytes were developed to the mitotic and 2-cell stage at 18 to 26 h after nuclear transfer. The incidence of in vitro development to the blastocyst stages was 21% of fused oocytes. Mitochondria of BFF eliminated rapidly and were not detected at 8 h after fusion. These results suggest that BFF can be successfully reprogrammed in enucleated bovine oocytes, and that reconstructed embryos can develop to the blastocyst stage.

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.429-436
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• 2016

Purpose: Solar ultraviolet (UV) radiation causes inflammation and matrix metalloproteinase (MMP) overexpression and extracellular matrix depletion, leading to skin photoaging such as wrinkle formation, dryness, and sagging. Activation of MMP is influenced by various molecules such as reactive oxygen species (ROS), proinflammatory cytokines, and transient receptor potential vanilloid type (TRPV)-1, which are increased in UV-irradiated skin cells. Aralia elata (AE) ethanolic extract was reported to inhibit ROS generation caused by UVB-irradiation in keratinocytes. In this study, we investigated the photoprotective effect of AE ethanolic extract on UVB-irradiated human keratinocytes (HaCaT) and human dermal fibroblasts (HDF). Methods: AE was freeze-dried, extracted in 70% ethanol, and concentrated. Skin cells were treated with AE extract for 24 h and then exposed to UVB ($55mJ/cm^2$). After 48 h of incubation, proinflammatory cytokines, MMP-1, type-1 procollagen, and TRPV-1 levels were measured by ELISA or Western blotting. Results: Treatment with AE extract ($100{\mu}g/mL$) significantly inhibited UVB-induced IL-6, IL-8, and $PGE_2$ production in HaCaT by 25.6%, 5.3%, and 70.2%, respectively, and also inhibited elevation of MMP-1 and TRPV-1 caused by UVB irradiation by 20.0% and 41.9%, respectively (p < 0.05). In HDF, AE extract treatment significantly inhibited both elevation of MMP-1 and reduction of type-1 procollagen caused by UVB irradiation (p < 0.05). In addition, type-1 procollagen was elevated by AE extract treatment in normal HDFs (p < 0.05). Conclusion: AE 70% ethanol extract has photoprotective ability via reduction of proinflammatory mediators, TRPV-1 and MMP-1 production, and elevation of collagen synthesis. Our findings suggest that AE extract might be a good natural material to protect against UVB-induced premature skin aging.