• 한국산업보건학회지
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• 제15권2호
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• pp.144-152
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• 2005

To evaluate the effect of lead biomarkers including bone lead on neurobehavioral test in lead workers, 652 lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 102 non-occupationally lead exposed blue collar workers in general manufacturing industries were also joined this study. All study subjects joined this study with written informed consent. The study variables of lead exposure were blood and patella lead. For the general characteristics of study subjects, standardized questionnaire regarding age, sex, past disease history, job duration, body mass index (BMI), drinking and smoking habit were provided. For the past history of neurotoxicity related diseases, all study subjects were interviewed by qualified occupational health physician. The results obtained were as follows: 1. Compared with controls without occupational lead exposure, lead exposed subjects had worse performance on all tests(p<0.05). 2. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for blood lead were negative for 13 of the 14 tests. Blood lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms & root MSD), Trail-Making Test B, Digit Symbol Substitution, Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention, and Purdue pegboard both hand). 3. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for patella lead were negative for 12 of the 14 tests. Patella lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms). Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention. Pursuit Aiming rest (no. of correct & no. of incorrect), Purdue pegboard non-dominant hand and both hand). With above results, blood lead and patella lead were associated with poorer performance of neurobehavioral tests. In addition, patella lead was confirmed to be better predictor of manual dexterity test in neurobehavioral test battery in lead workers

• 한국산업보건학회지
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• 제26권1호
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• pp.64-74
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• 2016

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.

• Wind and Structures
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• 제26권3호
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• pp.129-146
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• 2018

Extreme wind speed analysis has been carried out conventionally by assuming the extreme series data is stationary. However, time-varying trends of the extreme wind speed series could be detected at many surface meteorological stations in China. Two main reasons, exposure change and climate change, were provided to explain the temporal trends of daily maximum wind speed and annual maximum wind speed series data, recorded at Hangzhou (China) meteorological station. After making a correction on wind speed series for time varying exposure, it is necessary to perform non-stationary statistical modeling on the corrected extreme wind speed data series in addition to the classical extreme value analysis. The generalized extreme value (GEV) distribution with time-dependent location and scale parameters was selected as a non-stationary model to describe the corrected extreme wind speed series. The obtained non-stationary extreme value models were then used to estimate the non-stationary extreme wind speed quantiles with various mean recurrence intervals (MRIs) considering changing climate, and compared to the corresponding stationary ones with various MRIs for the Hangzhou area in China. The results indicate that the non-stationary property or dependence of extreme wind speed data should be carefully evaluated and reflected in the determination of design wind speeds.

• 한국융합학회논문지
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• 제9권12호
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• pp.295-299
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• 2018

본 연구의 목적은 30세이상 성인을 대상으로 간접흡연노출과 치주질환과의 관련성을 파악하고자 하였다. 연구자료는 2014년, 2015년 국민건강영양조사 자료를 이용하였으며, 5,146명을 최종분석대상자로 선정하였다. 치주질환은 지역사회 치주지수로 파악하였다. 이분형 로지스틱회귀분석을 이용하였으며, 95% 신뢰구간을 산출하였다. 본 연구결과 성별, 연령, 교육수준, 그리고 수입을 보정한 경우에서 요코티닌 수준이 50ng/mL미만에 비해 550ng/mL이상인 경우에서 치주질환 위험이 2.08배(95% CI=1.73-2.50) 높게 나타났다. 요코티닌 수준과 치주질환 위험 증가에 대한 용량-반응관계가 나타났다. 본 연구결과 간접흡연자에서 요코티닌 수준이 증가할수록 치주질환 위험이 증가하는 것으로 나타났다. 향후 간접흡연에 대한 노출을 감소시키기 위해 흡연자의 자발적인 금연참여를 권장하여야 할 것이다.

• 한국환경보건학회지
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• 제37권6호
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• pp.450-459
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• 2011

Objectives: Biomarkers in urine are important in assessing exposures to environmental or occupational chemicals and for evaluateing renal function by exposure from these chemicals. Spot urine samples are needed to adjust the concentration of these biomarkers for variations in urine dilution. This study was conducted to evaluate the suitability of adjusting the urinary concentration of cadmium (uCd) and arsenic (uAs) by specific gravity (SG) and urine creatinine (uCr). Methods: We measured the concentrations of blood cadmium (bCd), uCd, uAs, uCr, SG and N-acetyl-${\beta}$-D-glucosaminidase (NAG) activity, which is a sensitive marker of tubular damage by low dose Cd exposure, in spot urine samples collected from 536 individuals. The value of uCd, uAs and NAG were adjusted by SG and uCr. Results: The uCr levels were affected by gender (p < 0.01) and muscle mass (p < 0.01), while SG levels were affected by gender (p < 0.05). Unadjusted uCd and uAs were correlated with SG (uCd: r = 0.365, p < 0.01; uAs: r = 0.488, p < 0.01), uCr (uCd: r = 0.399, p < 0.01; uAs: r = 0.484, p < 0.01). uCd and uAs adjusted by SG were still correlated with SG (uCd: r = 0.360, p < 0.01, uAs: r = 0.483, p < 0.01). uCd and uAs adjusted by uCr and modified uCr ($M_{Cr}$) led to a significant negative correlation with uCr (uCd: r = -0.367, p < 0.01; uAs: r = -0.319, p < 0.01) and $M_{Cr}$ (uCd: r = -0.292, p < 0.01; uAs: r = -0.206, p < 0.01). However, uCd and uAs adjusted by conventional SG ($C_{SG}$) were disappeared from these urinary dilution effects (uCd: r = -0.081; uAs: r = 0.077). Conclusions: $C_{SG}$ adjustment appears to be more appropriate for variations in cadmium and arsenic in spot urine.

• 한국사회복지학
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• 제62권1호
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• pp.185-209
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• 2010

본 연구에서는 가정폭력 치료프로그램을 이수한 남성의 아내를 대상으로 남편의 정서적 폭력이 아내의 우울에 미치는 영향을 파악하고, 부부적응과 대처방식의 매개효과를 통합적으로 검증하였다. 이를 위해 남편이 가정폭력 치료프로그램을 이수한 후 남편의 신체적 폭력이 중단되었다고 응답한 아내들의 설문 77개를 구조방정식의 PLS(Partial Least Squares) 방법으로 분석하였다. 연구결과, 연구대상자의 71%인 55명이 조사시점으로부터 6개월 이내에 남편으로부터 정서적 폭력을 경험하였으며, 남편의 정서적 폭력을 경험할수록 우울이 높은 것으로 나타났다. 또한 남편의 정서적 폭력과 아내의 우울의 관계에서 부부적응과 수동적 대처의 매개효과가 검증되었다. 특히, 수동적 대처방식의 하위유형 가운데 회피 방식은 정서적 폭력과 우울의 관계를 매개할 뿐 아니라 부부적응을 높이는 것으로 나타났다. 이는 폭력 피해 아내가 부부간 갈등을 최소화하고 평화로운 부부관계를 유지하기 위해 회피 방식을 사용할 가능성이 높음을 시사한다.

• Environmental Analysis Health and Toxicology
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• 제28권
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• pp.15.1-15.8
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• 2013

Objectives The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. Methods We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. Results The geometric mean mercury levels in the blood, urine, and hair were $5.41{\mu}g/L$ (range, $0.00-15.84{\mu}g/L$), $1.17{\mu}g/g$-creatinine (range, $0.00-32.86{\mu}g/g$-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (${\beta}=25.96$; p =0.47), choice reaction time (${\beta}=50.37$; p =0.32), or the number of left-hand finger taps (${\beta}=-1.54$; p =0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (${\beta}=-3.86$; p =0.01). Conclusions We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion.

• Clinical and Experimental Pediatrics
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• 제48권5호
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• pp.476-480
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• 2005

Immunosuppressive therapy in pediatric renal transplant recipients is changing consequence of the increasing number of available immunosuppressive agents. The optimal use of immunosuppressive agents requires a thorough understanding of the pharmacokinetic characteristics, but the information on the pharmacokinetic characteristics of these drugs in pediatric transplant recipients is still limited. In general, patients younger than 5 years old show higher clearance rates, therefore the need for higher dosages in younger patients seems evident. By the therapeutic drug monitoring, trough($C_{min}$) and peak level($C_{max}$) are measured and the area under the blood concentration-time curve(AUC), which is taken as being representative of total systemic exposure can be calculated. Cyclosporine A (CSA) has poor bioavailability, which contributes to high inter- and intra-patient pharmacokinetic variability. CSA concentration measured 2 hours after administration($C_2$) has better correlation with the AUC than $C_{min}$ and is an alternative technique that predicts the AUC. Tacrolimus(Tac) has a great deal of inter-individual variability like CSA but intra-individual variability in systemic exposure is considered to be low. Both CSA and Tac are metabolized by a cytochrome P-450 enzyme isoform(CYP3A4). We should consider changing the dosages when CSA or Tac is used in combination with the medicines that inhibit or induce the CYP3A4. In case of steroid-free immunosuppressive therapy, the blood concentration of Tac should be frequently checked and dosage adjustment may be needed.

• Wind and Structures
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• 제3권3호
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• pp.177-191
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• 2000

This paper presents an approach for evaluating directionality effects for both wind speeds and wind loads in hurricane-prone regions. The focus of this study is on directional wind loads on low-rise structures. Using event-based simulation, hurricane directionality effects are determined for an open-terrain condition at various locations in the southeastern United States. The wind speed (or wind load) directionality factor, defined as the ratio of the N-year mean recurrence interval (MRI) wind speed (or wind load) in each direction to the non-directional N-year MRI wind speed (or wind load), is less than one but increases toward unity with increasing MRI. Thus, the degree of conservatism that results from neglecting directionality effects decreases with increasing MRI. It may be desirable to account for local exposure effects (siting effects such as shielding, orientation, etc.) in design. To account for these effects in a directionality adjustment, the factor described above for open terrain would need to be transformed to other terrains/exposures. A "local" directionality factor, therefore, must effectively combine these two adjustments (event directionality and siting or local exposure directionality). By also considering the direction-specific aerodynamic coefficient, a direction-dependent wind load can be evaluated. While the data necessary to make predictions of directional wind loads may not routinely be available in the case of low-rise structures, the concept is discussed and illustrated in this paper.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.143-144
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• 2006

In this paper, we proposed XP KMPR-1050 negative tone resist to replace SU-8 resist for multi-layer micro-structures and thick plating mold fabrication using UV-LIGA process. XP KMPR resist proposed in this paper can be easily striped using a common stripping solution such as NMP without damage of micro-structure. The conditions for the fabrication of XP KMPR micro-structure were optimized by adjustment of exposure and post-exposure bake(PEB). The $140{\mu}m$ -thick and an aspect ratio at least 10 micro-structure and multi-layer structures were successfully fabricated through the process conditions. Through-mold electroplating and PR striping of XP KMPR has been successfully demonstrated.