• Child Health Nursing Research
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• 제23권4호
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• pp.470-478
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• 2017

Purpose: This study was conducted to describe parenting stress in mothers of preschoolers who were born prematurely and to determine factors affecting parenting stress in child's problem behavior, mother-child interaction and parenting alliance. Methods: An exploratory survey study was conducted with 66 mothers of preschool children (5~6 years) with preterm births (PTB). Data were collected using Parenting Stress Index (PSI), Child Behavior Checklist (CBCL), Mother-Preschool Child Interaction Scale (MPIS), and Parenting Alliance Inventory (PAI). Results: Of the 66 mothers, 8(12.1%) showed high scores that were more than borderline for the PSI total score. In the multiple linear regression analysis, lower scores on the PAI (${\beta}=-.41$, p<.001), higher scores on the externalizing problem behavior of the CBCL (${\beta}=.40$, p=.001), and lower scores on the MPIS (${\beta}=-.21$, p=.043) were statistically significant contributors to maternal parenting stress. Conclusion: Findings indicate that mothers of PTB preschool children are at risk for parenting stress. Child's externalizing problem behavior, poor maternal-child interaction and parenting alliance were independent factors raising maternal parenting stress. More attention is needed on paternal parenting support, child's behavioral development, interaction with children for effective prevention and management of maternal parenting stress of PTB young children.

• Child Health Nursing Research
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• 제22권1호
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• pp.45-53
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• 2016

Purpose: The study was done to investigate behavioral problems in toddlers who were born prematurely and to analyze related factors. Methods: A cross-sectional explorative study was conducted with 72 preterm birth (PTB) children at 24 to 41 months of corrected age who were born at 28 to 37 weeks' gestation. During home visits, behavior problems were assessed using the Behavior Rating Index for Children (BRIC). Using a BRIC score of ${\geq}30$, children with suspected behavior problems were grouped in the non-regular behavior group. Results: Of the children, 38.9% belong to the non-regular behavior group. The mental development index score for the Korean-Bayley Scale of Infant Development- II was higher for the non-regular behavior group compared to the regular behavior group (t=2.26, p=.027). Logistic regression analysis showed that lower maternal attachment (<96, OR=3.4, 95% CI[1.1, 10.4]) and higher parenting stress (${\geq}97$, OR=4.8, 95% CI[1.3, 17.3]) were independently related to non-regular behavior. Conclusion: PTB Toddlers are at risk for behavior problems which are associated with low cognitive performance. Maternal-child attachment and maternal parenting stress were strongly related to behavior problems in these children. More attention is needed to understand possible behavior problems in young children with PTB, particularly focusing on maternal-child interaction and maternal mental well-being.

• Molecules and Cells
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• 제42권3호
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• pp.245-251
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• 2019

Ependymal cells constitute the multi-ciliated epithelium, which lines the brain ventricular lumen. Although ependymal cells originate from radial glial cells in the perinatal rodent brain, the exact mechanisms underlying the full differentiation of ependymal cells are poorly understood. In this report, we present evidence that the Anks1a phosphotyrosine binding domain (PTB) adaptor is required for the proper development of ependymal cells in the rodent postnatal brain. Anks1a gene trap targeted LacZ reporter analysis revealed that Anks1a is expressed prominently in the ventricular region of the early postnatal brain and that its expression is restricted to mature ependymal cells during postnatal brain development. In addition, Anks1a-deficient ependymal cells were shown to possess type B cell characteristics, suggesting that ependymal cells require Anks1a in order to be fully differentiated. Finally, Anks1a overexpression in the lateral wall of the neonatal brain resulted in an increase in the number of ependymal cells during postnatal brain development. Altogether, our results suggest that ependymal cells require Anks1a PTB adaptor for their proper development.

• Journal of Preventive Medicine and Public Health
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• 제49권3호
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• pp.165-175
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• 2016

Objectives: The present study was undertaken to study the maternal risk factors for preterm birth (PTB) and low birth weight (LBW) with a special emphasis on assessing the proportions of maternal genitourinary and periodontal infections among Indian women and their association with adverse pregnancy outcomes. Methods: A hospital-based prospective study comprising 790 pregnant women visiting the obstetrics clinic for a routine antenatal check-up was undertaken. Once recruited, all study participants underwent clinical and microbiological investigations for genitourinary infections followed by a dental check-up for the presence of periodontitis. The study participants were followed up until their delivery to record the pregnancy outcomes. Infectious and non-infectious risk factors for PTB and LBW were assessed using univariate and multivariate Cox regression analysis. Independent risk factors for PTB and LBW were reported in terms of adjusted relative risk (ARR) with the 95% confidence interval (CI). Results: Rates of PTB and LBW in the study population were 7.6% and 11.4%, respectively. Previous preterm delivery (ARR, 5.37; 95% CI, 1.5 to 19.1), periodontitis (ARR, 2.39; 95% CI, 1.1 to 4.9), Oligohydramnios (ARR, 5.23; 95% CI, 2.4 to 11.5), presence of Nugent's intermediate vaginal flora (ARR, 2.75; 95% CI, 1.4 to 5.1), gestational diabetes mellitus (ARR, 2.91; 95% CI, 1.0 to 8.3), and maternal height <1.50 m (ARR, 2.21; 95% CI, 1.1 to 4.1) were risk factors for PTB, while periodontitis (ARR, 3.38; 95% CI, 1.6 to 6.9), gestational hypertension (ARR, 3.70; 95% CI, 1.3 to 10.8), maternal height <1.50 m (ARR, 2.66; 95% CI, 1.3 to 5.1) and genital infection during later stages of pregnancy (ARR, 2.79; 95% CI, 1.2 to 6.1) were independent risk factors for LBW. Conclusions: Our study findings underscore the need to consider screening for potential genitourinary and periodontal infections during routine antenatal care in developing countries.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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• pp.3-3
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• 2003

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.68-70
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• 2008

레이저 빔 프린터의 인쇄 품질은 화상 인쇄 과정에 직접적으로 관계되는 OPC 드럼(Organic Photoconductive Drum) 및 PTB(Paper Transfer Belt)의 운전 속도 특성과 관계 있는 것으로 알려져 있다. 그러나 그 관계가 정량적으로 연구된 바는 없었다. 본 논문에서는 인쇄 동작중인 OPC 드럼 및 PTB의 실제 속도를 측정하고, 속도 측정 결과에 나타나는 특성이 실제 인쇄 결과에 미치는 영향을 정량적으로 분석한다. 또한 위의 속도 측정 및 분석 결과를 바탕으로 하여 레이저 빔 프린터의 인쇄 품질을 향상시킬 수 있는 방법을 제안하고, 실험을 통해 그 타당성을 검토한다. 제안 된 방법에의해 인쇄 품질의 정도(Accuracy)가 5배이상 개선됨을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제23회 학술발표회 초록집
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• pp.135-135
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• 2002

• 한국진공학회지
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• 제22권4호
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• pp.211-217
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• 2013

$PCDTBT:PC_{71}BM$과 $PTB7:PC_{71}BM$을 유기고분자 활성층 재료로 이용한 Bulk Hetero-Junction (BHJ) 구조의 유기박막태양전지를 플라스틱 기판 위에 각각 제작하여, 시간변화에 따른 단락전류밀도($J_{SC}$), 개방전압($V_{OC}$), 곡선인자(FF) 및 전력변환효율(PCE) 등 출력특성의 변화에 대해 고찰하였다. 유기박막태양전지의 출력특성 파라메터는 시간 경과에 따라 모두 감소하는 경향을 나타내었으며, 특히 개방전압의 감소폭이 컸다. 이러한 개방전압 감소의 원인은 빛에 대한 장시간의 노출과 산소를 포함하는 수분과의 접촉에 의한 LUMO 준위와 HOMO 준위 차의 감소가 그 원인이라 생각되며, 그 메커니즘에 대해 고찰하였다. 또한 유기박막태양전지 소자의 직렬 및 병렬 저항 값은 감소하다가 다시 증가하는 경향을 보였다. 이는 LUMO 준위와 HOMO 준위 차가 감소함에 의한 것과 공액 고분자 활성층 내부에서의 열적과정 손실에 기인하여 전극과 고분자의 계면에서의 접촉저항의 증가 때문이라고 생각된다. 유기박막태양전지의 전력변환효율은 초기에 급격한 감소를 보이다가 시간이 지날수록 감소폭이 차츰 둔화되어 한계치에 도달한 후, 포화되는 경향을 보였다. 이것이 유기박막태양전지가 실제 구동에서 발생시킬 수 있는 최소 출력특성값인 것으로 판단된다.

• 대한방사선치료학회지
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• 제16권2호
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• pp.19-24
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• 2004

목적 : Pelvis내에 존재하는 large lesion과 inguinal lymph node를 동시에 치료하고자 할때 femoral head에 과도한 선량을 피할 목적으로 partial transmission block(이하PTB)이 사용되어져 왔다. 그러나 field가 서로 overlap되거나 분리되는 문제를 해결하기 위한 다소 복잡하고 시간도 많이 걸리는 어려움이 있어 본 논문에서는 real block과 MLC를 이용하여 각각 PTB를 제작한 후 몇 가지 비교를 통하여 두 가지 중 실제 임상에 더 효율적으로 사용할 수 있는 방법을 연구하였다. 대상 및 방법 : 실제 치료 환자를 대상으로 디자인 된 PTB를 real block과 MLC를 이용하여 각각 제작한 뒤 아크릴 phantom으로 환자의 두께를 재현하고 치료 시와 동일한 조건으로 노광된 film을 획득하였다. field간에 overlap되는 부분과 분리되는 부분은 block을 미세 조장한 후 다시 촬영하였으며 오차가 1mm이내에 들어 올때까지 junction을 반복 tuning하였다. 두 block을 재현성, 제작 편의성, 제작 시간으로 나누어 비료 분석하였다. 재현성은 5회 반복 측정을 실시하였으며, 제작 편의성 및 제작 시간은 real block과 MLC가 각각 제작 시작 시간부터 완성되는 시점까지에 대하여 측정하였다. 결과 : PTB를 제작함에 있어서 real block과 MLC는 재현성 면에서는 유의할 만한 차이를 보이지 않았다. 그러나 제작 편의성에 있어서는 MLC가 junction tuning을 더 간편하게 수행 할 수 있었으며, 제작 시간 면에 있어서도 MLC가 real block에 비해 약$33\%$정도의 시간 절감 효과가 있음을 알 수 있었다. 결론 : PTB를 제작함에 있어서 real block과 MLC를 이용하는 것이 각각 장단점을 가지고 있으나 real block은 제작 편의성면에서 유연서이 떨어짐으로 각 fie의 junction을 tuning하는데 매우 어려움이 따름과 동시에 비교적 정확한 junction tuning을 시행할 수 있음을 알수 있었다. MLC특성상 발생되는 계단형태의 junction을 보완하여 PTB를 제작한다면 실제 임상에서 훨씬 간편하고 효율성 있는 업무를 수행할 수 있을 것으로 사료된다.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.11.1-11.19
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• 2015

Objectives The objective of this study was to conduct a systematic review to provide summarized evidence on the association between maternal exposure to particulate air pollution and birth weight (BW) and preterm birth (PTB) after taking into consideration the potential confounding effect of maternal smoking. Methods We systematically searched all published cohort and case-control studies examining BW and PTB association with particulate matter (PM, less than or equal to $2.5{\mu}m$ and $10.0{\mu}m$ in diameter, $PM_{2.5}$ and $PM_{10}$, respectively) from PubMed and Web of Science, from January 1980 to April 2015. We extracted coefficients for continuous BW and odds ratio (OR) for PTB from each individual study, and meta-analysis was used to combine the coefficient and OR of individual studies. The methodological quality of individual study was assessed using a standard protocol proposed by Downs and Black. Forty-four studies met the inclusion criteria. Results In random effects meta-analyses, BW as a continuous outcome was negatively associated with $10{\mu}g/m^3$ increase in $PM_{10}$ (-10.31 g; 95% confidence interval [CI], -13.57 to -3.13 g; I-squared=0%, p=0.947) and $PM_{2.5}$ (-22.17 g; 95% CI, -37.93 to -6.41 g; Isquared=92.3%, p<0.001) exposure during entire pregnancy, adjusted for maternal smoking. A significantly increased risk of PTB per $10{\mu}g/m^3$ increase in $PM_{10}$ (OR, 1.23; 95% CI, 1.04 to 1.41; I-squared=0%, p=0.977) and $PM_{2.5}$ (OR, 1.14; 95% CI, 1.06 to 1.22; I-squared=92.5%, p<0.001) exposure during entire pregnancy was observed. Effect size of change in BW per $10{\mu}g/m^3$ increase in PM tended to report stronger associations after adjustment for maternal smoking. Conclusions While this systematic review supports an adverse impact of maternal exposure to particulate air pollution on birth outcomes, variation in effects by exposure period and sources of heterogeneity between studies should be further explored.