• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.21-27
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• 2010

Purpose : In contrast with traditional time-cycled, pressure-limited ventilation, during volume-controlled ventilation, a nearly constant tidal volume is delivered with reducing volutrauma and the episodes of hypoxemia. The aim of this study was to compare the efficacy of pressure-regulated, volume controlled ventilation (PRVC) to Synchronized intermittent mandatory ventilation (SIMV) in VLBW infants with respiratory distress syndrome (RDS).Methods : 34 very low birth weight (VLBW) infants who had RDS were randomized to receive either PRVC or SIMV with surfactant administration : PRVC group (n=14) and SIMV group (n=20). We compared peak inspiratory pressure (PIP), duration of mechanical ventilation, and complications associated with ventilation, respectively with medical records. Results : There were no statistical differences in clinical characteristics between the groups. After surfactant administration, PIP was significantly lower during PRVC ventilation for 48hrs and accumulatevive value of decreased PIP was higher during PRVC ventilation for 24hrs (P<0.05). Duration of ventilation and incidence of complications was no significant difference. Conclusion : PRVC is the mode in which the smallest level of PIP required to deliver the preset tidal volume in VLBW infants with RDS, adaptively responding to compliance change in lung after surfactant replacement.

• Neonatal Medicine
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• v.17 no.2
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• pp.193-200
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• 2010

Purpose: Feeding desaturation is a common problem among preterm infants which can result in prolonged hospital stays, longterm feeding difficulties and growth delay. The purpose of this study was to identify the characteristics of premature infants with feeding desaturation and to examine the effect of orocutaneous stimulation on oral feeding. Methods: During the first phase of this study, 125 extremely low birth weight infants were reviewed retrospectively. Characteristics between infants with feeding desaturation (n=34) and those without feeding desaturation (n=91) were examined. During the second phase, 29 infants recruited from March, 2009 to May, 2010 were subjected to orocutaneous stimulation. The results of orocutaneous stimulation were compared to a control group (n=81). Results: The first phase of the study revealed that extremely low birth weight infants with feeding desaturation were significantly lower in gestational ages at birth, and had lower 5 minute apgar scores, more gastroesophageal refluxes and bronchopulmonary dysplasia. Infants without feeding desaturation reached full enteral feeding significantly earlier and showed shorter duration of hospital stay. At the second phase, infants in the intervention group showed shorter days to achieve initiation of bottle feeding, shorter days in achievement of full bottle feeding, last episodes of feeding desaturation and length of hospital stay compared to the control group of similar characteristics. Conclusion: Orocutaneous stimulation among extremely low birth weight infants results in earlier achievement of full bottle feedings without episodes of feeding desaturation hence shortens the length of hospital stay.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

• Journal of Aquaculture
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• v.15 no.2
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• pp.95-101
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• 2002

During the periods from lily to October, 2000 in Hongseong and lucy to October, 2001 in Taean in the west coast of Korea, the following environmental conditions prevailed : water temperature : 22.0~26.817, salinity 27.23 ~30.80%, dissolved oxygen 4.12 ~6.26 ml/l, pH 7.89 ~8.09, phosphate 0.39 ~0.65 $\mu m$ , inorganic nitrogen 5.05~9.26 $\mu m$, suspended solid 5.4~20.8 mg/l and chemical oxygen demand 1.12~1.87 mg/l. The B-shaped veliger larvae of the Ark shell occurred in maximum number at $25^{\circ}C$ prevailing from mid-August at Hongseong and Taean. Full grown larvae reached maximum abundance from late August. To identify the effectiveness of the substratum for spat collection, raschel net were tested to Larval settlement. The most effective depth to collect the larvae in natural environment was the collectors suspended at 7~8 m depth. At these depths, about 49 to 94 spats were found on the collector (40$\times$50 cm), The growth of shell height (Y) to shell length (X), and total weight (W) to shell length (L) could be formulated as follows respectively: Hongseong: SH = 0.7168 SL -0.6466 ( $r^2$ = 0.9839), TW = $0.0001SL^{3.1705}$ ($r^2$ = 0.9882) Taean: SH = 0.736 SL -0.8824 ($r^2$ : 0.9899), TW : 0.00005 $SL^{3.3731}$ ($r^2$ : 0.9899)

• Neonatal Medicine
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• v.18 no.1
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• pp.111-116
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• 2011

Purpose: To evaluate the impact of delayed interval delivery on neonatal outcomes. Methods: This was a retrospective study of infants who were born at Seoul National University Hospital by delayed interval delivery from June 2005 to July 2010. Outcomes (neonatal mortality and morbidity) of later babies were compared to those of the first babies and the control group whose gestational ages and birth weights were similar to them. Results: There were 4 twin and 5 triplet pregnancies. The first babies (group 1, n=9) were delivered at $22^{+6}$ to $27^{+5}$ weeks of gestational age, and the later babies (group 2, n=14) were born at $24^{+6}$ to $28^{+0}$ weeks. The mean interval between the first and later deliveries was 10 days, and there was no delay between the second and third deliveries in all triplet pregnancies. There were more small for gestational age (SGA) infants in group 1 than group 2 (66.7% and 21.4% respectively, P=0.03). Two of three babies who died in group 1 were born before 24 weeks of gestational age and expired within a week after birth. The mortality rate of group 2 (7.1%) was lower than group 1 (33.3%), but not significantly (P=0.106). The control group matched to group 2 consisted of 28 infants. There were no significant differences in neonatal mortality and morbidity between the two groups. Conclusion: Although there is a limitation to the number of infants in this study, it suggested that delayed delivery in a multiple pregnancy could decrease the incidence of SGA of the remaining fetuses and that prolonged gestation would not be harmful to those fetuses after birth.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1324-1329
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• 2005

Purpose : The aim of this study was to evaluate recent improvements in the survival rate of extremely low birth weight (ELBW) infants and to identify perinatal and management factors that are associated with improved survival. Methods : Two groups of ELBW infants who were admitted to our neonatal intensive care unit (NICU) during two distinct eras : November 1994-December 1999 (Period 1 : n=100) and January 2000-April 2004 (Period 2 : n=166) were retrospectively reviewed. Results : Despite the younger gestational age and smaller birth weight of the ELBW infants in period 2, not only did their survival rate increased to 75 percent from 60 percent in period 1, but their incidence of morbidities such as bronchopulmonary dysplasia, confimed sepsis and intraventricular hemorrhage (${\geq}$Grade III) also declined. Factors significantly associated with improved survival included the use of antenatal steroids, a longer duration of nasal continuous positive airway pressure and the absence of intraventricular hemorrhage (${\geq}$Grade III). Conclusion : We believe that optimized clinical practice, that emphasized less invasive care, contributed to the recent improvements in the survival rate of ELBW infants.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.295-302
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• 2009

Purpose : To report our experience of gastrointestinal (GI) operations (OP) performed in very low birth weight infants (VLBWI) and to evaluate their clinical characteristics. Methods : Among the 1,117 VLBWI admitted to the SMC neonatal intensive care unit from November 1994 to February 2007, the medical records of 37 infants who underwent GI OP (except inguinal hernia OP) and 1,080 VLBWI without GI OP were retrospectively reviewed. Results : The mean gestational age ($27^{+6}2^{+3}$ vs. $28^{+5}{\pm}$2^{+6}$) and birth weight (979${\pm}$241 g vs. 1,071${\pm}$271 g) of the 37 VLBWI who underwent the GI OP was lower than the VLBWI without GI OP group (n=1,080). Mortality rates in the GI OP group were significantly higher than in the non GI OP group (28% vs. 15%, P<0.001). The incidence of cholestasis, retinopathy of prematurity and periventricular leukomalacia were higher in the GI OP group than in the non GI OP group, but the incidence of bronchopulmonary dysplasia was not significantly different between the GI OP group and the non GI OP group. For GI OP indications, focal intestinal perforation was most common and showed a more favorable outcome than necrotizing enterocolitis. Compared with an earlier 7-year period, 1994-2000, the incidence and survival rates increased in the subsequent 2001-2007 period. Conclusion : GI OP was associated with high mortality and morbidity in VLBWI. Further efforts to improve outcomes of GI OP in VLBWI should be investigated to improve the quality of care in VLBWI.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.248-254
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• 2007

Purpose : Inflammation plays a major role in the pathogenesis of RDS and BPD in the immature lung. We investigated the possible role of IL-10 and IL-12 in the cord blood of preterm newborns with RDS or BPD. Methods : Forty preterm newborns whose mothers received antenatal care at Ewha Womans University Mokdong Hospital between January 2003 to June 2005, and agreed to testing their cord blood samples were enrolled. The gestational ages were below 34 weeks. Cord blood level of IL-10 and IL-12 were determined by ELISA. We separated the patients into 2 groups (RDS group and non-RDS group, BPD group and non-BPD group) and compared the cytokine levels and clinical records of the groups. Results : Cord blood IL-10 level showed a significant inverse correlation with gestational age and birth weight (P=0.001, P=0.005). Preterm infants with RDS showed higher IL-10 level (1.0 vs 0.1 pg/mL; P=0.001) in the cord blood than those without RDS. The differences remained statistically significant after correction for the effect of gestational age between both preterm groups. Despite similar cord blood IL-10 levels, preterm infants with BPD showed no significant difference with those without BPD. Conclusion : Cord blood IL-10 levels are increased in preterm infants which may be due to the immuno-suppression occurring during pregnancy and to fetal immaturity because these levels are inversely correlated with the gestational age. So, Cord blood IL-10 level can be used as the predictor of RDS.

• Pediatric Infection and Vaccine
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• v.12 no.1
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• pp.67-74
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• 2005

Purpose : The incidence of mortality associated with respiratory difficulties is decreasing nowadays contributed to the development of neonatology. However, complications associated with mechanical ventilator are increasing. This study is to determine clinical manifestations, diagnositc availability of the endotracheal tip culture in patients with Ventilator-Associated Pneumonia(VAP) in neonatal intensive care unit(NICU). Methods : A retrospective analysis of 50 neonates who were admitted to the NICU of Kangnam Sacred Heart Hospital and had given mechanical ventilator from 1 January 2000 to 30 June 2003. VAP group defined as neonates who had pneumonia with mechanical ventilation longer than 48 hours. They were classified into VAP group(n=13) and control group (n=37) and the prevalence, microorganisms cultured from the endotracheal tube tip and risk factors were investigated. Results : The prevalence of VAP was 26.0%(n=13) and the most dominant microorganism cultured in our NICU was methicillin-resistant coagulase negative staphylococcus(MR-CNS) in 4 cases. Other microorganisms were Pseudomonas, Enterobacter, methicillin-resistant Staphylococcus aureus(MRSA) and Klebsiella. Gestational age, birth weight, Apgar score, respiratory distress syndrome, retinopathy of prematurity, bronchopulmonary dysplasia, sepsis, renal failure, pulmonary hemorrhage, pneumothorax were not different significantly between two groups except intraventricular hemorrhage(P<0.001) and patent ductus arteriosus(P<0.05). Duration of hospital stay and mortality rate were also not different significantly. Conclusion : VAP occurred at a significant rate among mechanically ventilated NICU patients. Despite of limitation of encotracheal tip culture, the most common microorganism was MR-CNS. We should be aware of occurrence of VAP in NICU neonate who were with mechanical ventilator and should treat with great care.

• Neonatal Medicine
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• v.16 no.2
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• pp.205-212
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• 2009

Purpose: The purpose of this study was to evaluate the differences according to the hospitals of antenatal care in premature infants. Methods: We retrospectively reviewed the medical records of premature infants with gestational ages <37 weeks and very low birth weights who were admitted immediately after birth to the neonatal intensive care unit (NICU) at the Dongguk University Ilsan Hospital between March 2007 and February 2009. The hospitals of antenatal care were divided into two levels (primary antenatal care hospital: hospitals with less than a level 2 NICU, secondary antenatal care hospital: hospitals with a level 3 NICU) based on the level of NICU in hospitals. In addition, total infants were divided into two groups (Immediate group: infants born within 24 hours of maternal admission, Delayed group: infants born after 24 hours of maternal admission). The differences between maternal and neonatal variables in each groups were studied. Results: Neonates in secondary antenatal care hospitals comprised 11.0% of the study neonates (10 of 91). We compared with two groups (primary antenatal care hospital and secondary antenatal care hospital), but there were no differences in all subjects. However, the 1 minute Apgar score ($\leq3$) was lower in the immediate group than the delayed group. Conclusion: Shorter duration of maternal admission to delivery was associated with a lower 1 minute Apgar score of neonates. These findings suggest that if maintenance of pregnancy is difficult when high-risk gravidas are transferred, clinicians must prepare for emergencies of neonates.