• 한국군사과학기술학회지
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• 제22권4호
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• pp.441-451
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• 2019

When a store is launched, the umbilical plug should be separated from the launcher without any physical interference and fragments. In order to satisfy these conditions, an umbilical plug and an umbilical separating device were designed. The plug is separated from the receptacle of the store while moving along inclined planes by the store thrust and the spring force connected from the launcher to the plug. As a result of the prototype test, the hanger on the store collided with the plug. Several tests were conducted after some actions were taken to prevent the collision. However, not only the same phenomenon was repeated, but also fragmentation occurred. In this study, the non-colliding conditions were analyzed through rigid and flexible multi-body dynamics analysis.

• Ocean Systems Engineering
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• 제3권2호
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• pp.97-122
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• 2013

For the optimization design and strength evaluation of the umbilical cable, the calculation of cross section stress is of great importance and very time consuming. To calculate the cross section stress under combined tension and bending loads, a new integrated analytical model of umbilical cable is presented in this paper. Based on the Hook's law, the axial strain of helical components serves as the tensile stress. Considering the effects of friction between helical components, the bending stress is divided into elastic bending stress and friction stress. For the former, the elastic bending stress, the curvature of helical components is deduced; and for the latter, the shear stress before and after the slipping of helical components is determined. This new analytical model is validated by the experimental results of an umbilical cable. Further, this model is applied to estimate the extreme strength and fatigue life of the umbilical cable used in South China Sea.

• IMMUNE NETWORK
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• 제2권3호
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• pp.166-174
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• 2002

Background: Human umbilical cord bloods, which could be taken during the delivery are utilized as a source of hematopoietic stem cells. Also in cord blood, there are several kinds of stem cells such as endothelial and mesenchymal stem cells. Methods: We isolated the mesenchymal stem cells from human umbilical cord bloods and confirmed the differentiation of these cells into osteoblast progenitor cells. The mesenchymal stem cells derived from umbilical cord blood have the ability to differentiate into specific tissue cells, which is one of characteristics of stem cells. These cells were originated from the multipolar shaped cells out of adherent cells of the umbilical cord blood mononuclear cell culture. Results: The mesenchymal stem cells expressed cell surface antigen CD13, CD90, CD102, CD105, ${\alpha}$-smooth muscle actin and cytoplasmic antigen vimentine. Having cultrued these cells in bone formation media, we observed the formation of extracellular matrix and the expression of alkaline phosphatase and of mRNA of cbfa-1, ostoecalcin and type I collagen. Conclusion: From these results we concluded that the cells isolated from the umbilical cord blood were mesenchymal stem cells, which we could differentiate into osteoblast when cultured in bone formation media. In short, it is suggested that these cells could be used as a new source of stem cells, which has the probability to alternate the embryonic stem cells.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.341-347
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• 1999

Pregnant Yorkshire gilts were utilized to investigate the efficacy of exogenous administration of pST and/or insulin in enhancing prenatal piglet survival, uteroplacental and umbilical cord growth and development. Gilts were randomly assigned in a $2{\times}2$ factorial arrangement to four treatment combinations consisting of either daily i.m. injections of 5 mg pST (P, n=23); 0.50 IU/kg of insulin (I, n=23); combination of pST and insulin (P+I, n=23); or 1 ml of saline as control (C, n=23) from gestation Day 30 to 70. All gilts were sacrificed on gestation d 113 to evaluate piglet survival and uteroplacental or umbilical cord development Uteri were longer (346.3 vs 325.7 cm; p<0.05), and heavier (3122.8 vs 2940.7 g; p<0.05) in insulin treated gilts. Only placental macroscopic surface area was enhanced by maternal insulin injections (p<0.05) Incidence of umbilical cord abnormalities were low (14.3%), and they were independent of maternal treatment, occurring more in short cords than in long ones (21 vs 12%; p<0.05). A 6% increase in cord length (53.2 vs 48.6 cm; p=<0.05) was observed in piglets from treated gilts compared with controls. Significant sex differences (in favour of males) were observed in piglet weight, crown rump length and for most umbilical or placental parameters. Gilt weight gains from breeding to Day 113 of gestation were 10% and 15% greater in pST and insulin treated gilts compared with controls. These data indicate that prepartum injections of pST and/or insulin to gestating gilts seem to have a beneficial effect on uteroplacental or umbilical cord development and promote conditions conducive for perinatal piglet survival.

• Journal of Nutrition and Health
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• 제32권5호
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• pp.577-584
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• 1999

The correlation between maternal lipid nutritional status during pregnancy and gestational length was investigated. Subjects consisted of 30 full-term delivery mothers, 30 preterm delivery mothers, and babies of both groups. Dietary fat intake during pregnancy and serum lipid levels in mother and umbilical serum were measured. The mean daily intake levels of fatty acid during pregnancy were lower than the recommended dietary allowances, while $\omega$6/$\omega$3 ratios of dietary fatty acids were acceptable. For preterm delivery mothers, fatty acid intake levels to be lower than those in full-term delivery mothers, especially DHA intake of these two groups was significantly different. During gestation, hyperlipidemia was apparent in the pregnant women. The serum lipid contents of preterm delivery mothers tended to be lower than those of full-term delivery mothers, and umbilical cord serum lipid contents of the preterm delivery group tended to be higher than those of the full-term delivery group. Total cholesterol levels in the umbilical cord serum of preterm babies were significantly higher than those of full-term delivery group. On the other hand, total cholesterol and HDL-cholesterol levels between umbilical cord serum and maternal serum were positively correlated in the preterm delivery group. Concerning, energy and fatty acid intakes were more closely associated with umbilical cord serum lipid levels in full-term babies, but negatively associated in preterm babies. It was concluded that gestational length was related to the dietary intake of fatty acids such as DHA in pregnant women. For better understanding, the ralationship between placental lipid transport mechanisms and gestational length needs to be explored.

• Journal of Yeungnam Medical Science
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• 제8권1호
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• pp.98-106
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• 1991

본 연구에서 정상적인 분만 산모의 제대동맥혈의 pH와 신생아의 Apgar score및 질병의 이환유무를 관찰하였고, 또한 분만시 제대결찰 시간의 경과가 태아의 혈중가스농도의 변화 및 신생아의 건강에 미치는가를 분석해 보였다. 본 연구의 결과, 불량한 Apgar score를 보인 많은 신생아에서 산성증을 보인 경우가 적음으로 제대동맥혈의 pH와 Apgar score의 상관관계는 미약한 것으로 생각되며, 제대동맥혈의 분석이 Apgar score보다는 태아의 건강상태의 파악에는 좀더 도움이 되리라 생각한다. 그러나 제대동맥혈의 pH와 Apgar score등, 단독적인 지표만으로 초기 신생아의 건강 상태 및 평가 및 관리에 임상적 의의를 부여하기는 어려웠다. 또한 분만시 제대혈관의 결찰의 시간의 결정은 대부분의 산과의들의 토론의 대상처럼 어느 시간이 태아의 건강에 도움이 되는가는 결정할 수가 없었다. 그러나 신생아의 건강 상태를 파악하기 위해서 제대동맥혈을 채취할 경우는, 조기결찰의 특별한 적응증이 없는 한 분만직후에는 제대결찰을 시행하지 않고 즉시 제대동맥혈을 채취하는 것이 바람직하다고 할 수 있다. 이는 분만직후의 제대동맥혈이 분만진통이나 분만자체가 태아에 미치는 영향을 가장 잘 반영하기 때문으로 생각되어지기 때문이다. 태아의 건강의 지표로서 Apgar score, 제대혈관내의 pH와 가스농도의 분석이 그 정확도와 감수성을 더하기 위해서는 좀 더 많은 대상군과 좀 더 다양한 대조군으로 연구를 하여야 할 것 으로 사료된다.

• Journal of Nutrition and Health
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• 제31권8호
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• pp.1263-1269
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• 1998

The maintenance of adequate folate levels in the umbilical cord blood is esential for supplying tissue requirements of fetal growth. However, there is data on folate levels in the cord blood of Korean infant. The present investigation was undertaken to determine folate levels in cord blood and aassess relationships between folate levels and pregnancy outcomes. Dietary and supplementary folate intake was obtained from thirty subjects who were in the third trimester fo pregancy . The umbilical cord blood was drawn at delivery and pregnancy outcomes for the subjects were collected from their medical records. Erythrocyte and plasma folate levels in the cord blood were analyzed. The subjects were divided into two groups ; high folate (HF, $\geq$654ng/ml) and low folate (LF, <654ng/ml) groups according to erythrocyte folate levels in cord blood. Dietary folate intake and the amount of supplemental folates were not significantly different between the two experimental groups. However, infant birth weight (3540$\pm$295g) and placental weight(910$\pm$85g) for the HF group were significantly higher(p=0.0041 and p=0.109, respectively) than those for the LF group, which were 3127 $\pm$419g and 823$\pm$80g , respectively. Although it was not significant, the gestational weight gain for the HF group was 2.8kg higher than that for the LF group. Thus, the erythrocyte folate level in the cord blood was significantly related to infant birth weight and placental weight. These results confirm that a high erythrocyte folate level in the umbilical cord blood promotes both fetal and placental growth and improves gestational weight gain as well.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.289-295
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• 2002

This study was conducted to quantify of micronucleus frequencies in human umbilical cord blood by supravital staining method with acridine orange, and to find some factors that affected on micronucleus frequncies in humans. In this study, we used umbilical cord blood of new born infants that have sufficient reticulocytes compared with adult peripheral blood. The cord bloods were taken after childbirth from 60 normal infants in industrial and coastal region in Korea. The total of 3 ${mu}ell$ cord blood was applied to slide coated with acridine orange, and micronuclei were observed under fluorescent microscopy. Demographic factors and independent variables were collected from mothers by questionnaire. The frequencies of micronuclei in umbilical cord blood of new born infants were 0-5 per 2,000 reticulocytes by supravital staining method, and mean value and standard deviation were 1.75$\pm$0.97. There were no significant difference by the regions, smoking habits of father or mother. However, age of mother showed significant positive correlation with frequencies of micronuclei (p<0.05). Smoking at home by fathers also was found as a significant variable by muliple regression analysis. Therefore, further studies would be needed for genotoxicological evaluation of new born infants by microneuli test using supravital staining method.

• The Korean Journal of Physiology and Pharmacology
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• 제11권3호
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• pp.129-133
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• 2007

There are growing evidences suggesting a pivotal role of oxidative stress in the pathophysiology of preeclampsia. We investigated oxidative stress in the rat model of preeclampsia, and in clinical cases. Pregnant female rats were injected intraperitoneally with deoxycorticosterone acetate (DOCA) and given 0.9% saline as drinking water during their pregnancy. We assessed plasma $F_2-isoprostane(8-iso-PGF_{2{\alpha})$ and malondialdehyde (MDA) in a rat model, and the same markers in the plasma of maternal blood and fetal cord blood in pregnant women with preclampsia. Blood samples from the umbilical arteries and veins were collected separately. The concentrations of MDA were increased in the preeclampsia groups of animal and humans, compared with the control group; it was significantly increased in the umbilical artery and vein of the preeclampsia group. The concentrations of $F_2-isoprostane$ were elevated in the preeclampsia groups of animal and humans, compared with the control group, and the increase in $F_2-isoprostane$ concentration was prominent in the umbilical vein than umbilical artery of the preeclampsia group. Therefore, it appears that the placenta has an important role in the pathophysiology of preeclampsia, and the $F_2-isoprostane$ of the umbilical vein may serve as a relatively reliable marker for ischemic/hypoxic injury to the fetus during the perinatal period.

• Journal of Medicine and Life Science
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• 제21권3호
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• pp.102-105
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• 2024

Omental adhesions to the anterior abdominal wall are a common complication of abdominal surgery. Specific adhesions to the back of the umbilicus represent a challenge for safe laparoscopic access. In this case report, we describe a simplified two-port laparoscopic access procedure for retro-umbilical adhesiolysis. We concluded that successful adhesiolysis of retro-umbilical adhesions using the sequential Darwish and Lee-Haung points is feasible, and this procedure is a safe, minimally invasive alternative to the primary laparoscopic approach.