• Clinical and Experimental Pediatrics
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• 제57권8호
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• pp.363-369
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• 2014

Purpose: This study examines changes in developmental profiles of children with language delay over time and the clinical significance of assessment conducted at age 2-3 years. Methods: We retrospectively reviewed the medical records of 70 children (62 male, 8 female), who had visited the hospital because of delayed language development at 2-3 years, and were reassessed at ages 5-6. Language and cognitive abilities were assessed using multiple scales at the initial and follow-up visits. Results: At the initial test, 62 of the 70 children had mental development index (MDI) below 70 of Bayley Scales of Infant Development Test II. Of the 62 children in the follow-up assessment, 30 children (48.4%) remained within the same cognitive range (full-scale intelligence quotient, FSIQ<70 of Wechsler preschool and primary scale of intelligence), 12 had borderline intellectual functioning (FSIQ, 70-85), 6 improved to average intellectual functioning (FSIQ>85), and 5 had specific language impairment, 9 had autism spectrum disorders. At the initial test, 38 of the 70 children had cognitive developmental quotients (C-DQ) below 70. Of the 38 children in the follow-up assessment, 23 children (60.5%) remained within the same cognitive range (FSIQ<70). The correlation coefficient for MDI and FSIQ was 0.530 (P<0.0001) and that for C-DQ and FSIQ was 0.727 (P<0.0001). There was a strong correlation between C-DQ and FSIQ, and a moderate correlation between MDI and FSIQ. Conclusion: Low MDI scores reflect a specific delay in cognitive abilities, communication skills, or both. The C-DQ, receptive language development quotient, and social maturity quotient also help to distinguish between children with isolated language delay and children with cooccurring cognitive impairment. Moreover, changes in the developmental profile during preschool years are not unusual in children with language delay. Follow-up reassessments prior to the start of school are required for a more accurate diagnosis and intervention.

• 공업화학
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• 제9권7호
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• pp.1079-1084
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• 1998

우레탄 생성반응의 동역학을 조사하기 위해 지방족 이소시아네이트인 4,4'-dihexyl methane diisocyanate($H_{12}MDI$)와 1 관능기 알코올인 n-hexanol간의 반응을 실험적 측정과 수학적 모델링을 통해 연구하였다. 실험은 dibutyltin dilaurate(DBTDL)을 촉매로, 톨루엔을 용매로 온도, 촉매농도, [NCO]/[OH] 비 등을 변화시키면서 실시하였고, 반응동역학은 NCO기와 OH기의 반응에 의한 우레탄 생성반응 및 NCO기와 우레탄간의 반응에 의한 allophanate 생성반응 등 2가지 2차반응식으로 모사하였다. 반응속도상수는 Runge-Kutta 4th order 방법에 의한 전산모사방법으로 계산하였다. 대부분의 조건에서 실험치와 계산치가 잘 일치하여 본 연구에서 제안하는 반응 모델과 속도상수 계산방법이 적절함을 알 수 있었다. 또한 NCO기 90% 전환율에서 allophante/urethane의 비를 계산하였는데 대부분의 조건에서 20% 이상의 높은 값이 얻어져 allophanate 생성반응이 우레탄 물성에 중요한 영향을 미칠 수 있음을 알 수 있었다.

• Elastomers and Composites
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• 제36권4호
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• pp.268-277
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• 2001

PPG, PEG, trimethylolpropane(TMP) 등의 폴리올에 MDI(4,4'-diphenyl methane diisocyanate)를 각각 혼합하고 경화시켜 여러가지 물성을 측정하였다. 경화시간은 PEG와 TMP의 함량이 늘어날수록 짧게 나타났고 분자량의 효과보다는 관능기의 수에 더 큰 영향을 받았다. NCO-OH 반응은 NCO-NCO반응보다 활성적이고 빠르게 일어났다. 경도는 가교밀도와 분자구조의 영향을 받았으며 NCO-NCO 반응으로 생긴 도막은 취약하였고 NCO-OH간의 반응으로 생긴 도막은 유연하였다. 부착력은 결정화도와 수축율이 클수록 낮은 값을 나타내었으며 TMP 함량이 증량될수록 높은 값을 나타내었다. 난연성은 난연제의 종류와 함량에 영향을 받았으며 난연효과는 IXOL B-251이 가장 우수하였고 TCCP는 수지와의 상용성이 좋지 않아 부분적으로 분리되었다.

• Journal of the Korean Wood Science and Technology
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• 제34권4호
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• pp.31-36
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• 2006

본 연구는 UF resin의 접착성능을 개선하여 그 사용처의 확대하기 위하여 각 F/U 몰비별로 제조된 UF resin에 접착성능이 우수한 지방산-글리세롤-pMDI 당량비 1:1:4인 비교적 저가의 isocyanate prepolymer접착제를 선정하여 UF resin의 수지고형분 기준으로 0 wt%(대조구), 2 wt%, 5 wt%, 10 wt%, 25 wt%, 50 wt%로 첨가 혼합하여 접착 성능을 조사하였다. 그 결과, 상태 접착력(Type 2)은 F/U 몰비 1.4에서 가장 우수한 접착력을 준내수 접착력(Type 1.5)은 FGMDI첨가량이 25% 이상에서 KS 합판 접착성 기준인 $7.5kgf/cm^2$를 모두 상회하는 $11kgf/cm^2$ 이상을 나타내었다. 상태접착력대비 준내수 접착력의 평균 감소율은 F/U 몰비가 높아질수록, 지방산-글리세롤-pMDI접착제의 첨가량이 많아질수록 그 감소의 폭이 둔화되었다.

• 공업화학
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• 제8권2호
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• pp.308-314
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• 1997

폴리우레탄 전선도료 제조시의 TDI와 MDI의 blocking 반응에 미치는 촉매와 blocking reagents(BR)의 영향에 대하여 조사하였다. 1,4-diazabicyclo[2.2.2]octane(DABCO)와 tetramethyl guanidine(TMG)와 같은 촉매들은 NCO의 blocking 반응을 완결시키는데 필요한 것으로 나타났다. TMG는 DABCO에 비해 매우 빠른 반응속도를 보였다. TMG의 농도는 1%까지 반응도에 대하여 정량적으로 비례하였다. DABCO의 경우는 0.25%의 농도에서 가장 높은 반응도를 나타내었다. BR의 입체영향을 알아보기 위해 phenol, p-cresol, m-cresol, o-cresol, 2,4-xylenol과 같은 BR 등을 사용하였다. 예측한대로 입체장애가 적은 BR이 높은 반응도를 보였다. 또한 이 반응 시스템에서는 온도와 BR의 농도가 증가할수록 반응도가 증가하였다.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.580-587
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• 2017

목섬유 단열재는 친환경 고단열성에 기인하여 저에너지 및 쾌적하고 안전한 주거 공간 형성을 위한 핵심 건축재료로 고려된다. 본 연구에서는 서로 다른 접착제로 제조한 단열재용 저밀도섬유판의 폼알데하이드(HCHO) 총휘발성유기화합물(TVOC) 방출 및 화염에 의한 연소 형상을 조사하였다. 멜라민 요소 폼알데하이드(MUF), 페놀 폼알데하이드(PF), emulsified methylene diphenyl diisocyanate (eMDI) 및 라텍스 수지 접착제 등으로 제조한 저밀도섬유판 4종의 HCHO TVOC 방출 특성 및 연소 형상은 각각 챔버법과 화염실험을 통하여 분석하였다. 그 결과 MUF, eMDI, 라텍스 수지 접착제로 제조한 저밀도섬유판들은 Super $E_0$급의 우수한 HCHO 저방출 성능을 나타냈다. 반면 PF 수지로 제조된 저밀도섬유판은 $E_0$급 성능을 나타내었다. TVOC 방출량은 모든 저밀도섬유판이 국내 실내공기질 기준(이하 $400{\mu}g/m^2{\cdot}h$)을 만족하였으며, 기존 석유계 합성원료 기반의 단열재보다 낮은 수치를 나타냈다. 그중에서도 특히 eMDI 수지 접착제로 제조한 경우에서는 HCHO 및 TVOC 방출량이 각각 $0.14mg/{\ell}$, $12{\mu}g/m^2{\cdot}h$로 가장 낮게 측정되었다. 그러나 eMDI로 제조한 저밀도섬유판에서 방출된 VOC의 성분을 조사한 결과, 톨루엔 성분($3{\mu}g/m^2{\cdot}h$)이 소량 검출되었다. 화염에 의한 연소시험에서는 MUF 수지 접착제로 제조한 저밀도섬유판이 다른 경우에 비하여 연소 후 비교적 가장 양호한 형상을 나타내었다. HCHO 및 TVOC 방출 특성, 연소 형상을 고려하였을 때 단열재용 저밀도섬유판은 MUF 수지 접착제가 가장 적합할 것으로 판단된다.

• 동의생리병리학회지
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• 제21권1호
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• pp.86-92
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• 2007

Hibiscus sabdariffa L., a tropical beverage material, is used commonly as in folk medicine against hypertension, pyrexia, inflammation, liver disorders, and obesity. However, the mechanism by which Hibiscus sabdariffa L. modulates adipogenic differentiation is remained to be elusive. This report was designed to investigate the inhibitory effect of Hibiscus extract on insulin signaling pathway during adipocyte differentiation in 3T3-L1 preadipocytes. 3T3-L1 preadipocytes were differentiated with isobutylmethylxanthine, dexamethasone, and insulin (MDI) and followed by the addition of Hibiscus extract. Treatment with Hibiscus resulted in a decrease of lipid droplet accumulation, which was suppressed by PI-3 kinase inhibitor wortmannin in 3T3-L1 preadipocytes. Also, Hibiscus extract markedly attenuated the mRNA expression of adipogenic transcriptional factor PPAR${\gamma}$ and adipogenic hormon Leptin during adipogenesis. However, it did not affect the expression of adiponectin in 3T3-L1 preadipocytes differentiated with MDI mixture. Furthermore, Adipogenic differentiation by MDI mixture increased the phosphorylation and expression of PI3-Kinase and Akt in 3T3 preadipocytes, which was markedly suppressed by Hibiscus extract treatment. Taken together, our results suggest that Hibiscus extract suppressed the adipogenic differentiation of 3T3 preadipocytes through activation of PI3-Kinase and Akt signaling pathway.

• Natural Product Sciences
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• 제17권4호
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• pp.273-278
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• 2011

In this study, the effects of a methanol (MeOH) extract of Carduus crispus L. (Asteraceae) on adipogenesis was investigated in 3T3-L1 cells. To differentiate preadipocytes to adipocytes, confluent 3T3-L1 preadipocytes were treated with a hormone mixture, which included isobutylmethylxanthine, dexamethasone, and insulin (MDI). The methanol extract of C. crispus significantly decreased fat accumulation by inhibiting adipogenic signal transcriptional factors in MDI-induced 3T3-L1 cells in a dose-dependent manner. In MTT assays and on PI-staining, methanol extract of C. crispus inhibited the proliferation of 3T3-L1 cells during mitotic clonal expansion (MCE). The anti-adipogenic effect of the Carduus extract seemed to be associated with the upregulation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) pathways within the first 2 days after MDI treatment. These results suggest that methanol extract of C. crispus might be beneficial for the treatment of obesity.

• 아동학회지
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• 제25권5호
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• pp.147-161
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• 2004

This study was designed to explore developmental evaluation in healthy full-term, at risk preterm and full-term infants. Specifically the purposes of the study were to investigate Psychomotor Developmental Index(PDI) and Mental Developmental Index(MDI) based on Bayley Scales of Infant Development(1993). The subjects were 72 infants, 24 each for healthy full-term infants, 24 each for at risk preterm infants and 24 each for at risk full-term infants such as having neonatal asphyxia, hypoxic ischemic brain damage, respiratory distress syndrome. The data were analyzed through Kruskal-Wallis test and correlations to examine healthy full-term, at risk pre-term and at risk full-term infants. Results showed that there were significant differences among healthy full-term, at risk pre-term and at risk full-term infants in PDI and MDI. On the correlation with PDI and MDI, infants showed significant correlations. Early interventions for developmental improvement are required for functional outcome in these infants.

• 성인간호학회지
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• 제24권2호
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• pp.160-170
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• 2012

Purpose: The aim of this study was to assess knowledge, attitude, correct metered dose inhaler (MDI) use and compliance with self management among patients with chronic obstructive pulmonary disease (COPD). Methods: The participants of this study consisted of 109 COPD patients who were outpatients in C and K hospital located in G city from March 1 to September 30th, 2010. Data were measured using self-administered questionnaires and observational checklist. The data were analyzed using SPSS/WIN 18.0 program that included mean, standard deviation, ANOVA, Sheffe test, and Pearson's correlation. Results: There were significant relationships between knowledge and attitude (r=.33, $p$ <.001), between knowledge and correct MDI use (r=.37, $p$ <.001), and between knowledge and self-management compliance (r=.28, $p$=.003). There was significant relationship between attitude and self-management compliance (r=.33. $p$ <.001). In contrast, attitude was not significantly related to correct MDI use. Conclusion: The study showed that COPD knowledge and attitude of patients were related compliance in managing their disease. Therefore, strategies need to be utilized in education programs which would improve knowledge and subsequently improve attitude and compliance.