• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.100-105
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• 2022

Oblique car to car frontal impact is quite common on the road and series of studies have been done to realize this in the lab. At a certain angle of oblique crash a car (ego) is to travel at a speed of xkm/h to hit the other car(traffic) which is approaching to ego at a speed of ykm/h. Symmetry of the speed of two vehicles, x vs. y, is studied with respect to the impulse of the ego vehicle as well as occupant injury. If there is symmetry of speed of two vehicles, number of case studies needed to analyze the oblique frontal impact may decrease: ex. in the case of 30degree oblique crash 40km/h (ego) / 80km/h (traffic) will show the similar behavior as 80km/h (ego) / 40km/h (traffic) crash.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.588-597
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• 2016

In this study, we attempted to improve the biogas production efficiency by varying the mixing ratio of the mixed sludge of organic wastes in the improved single-phase anaerobic digestion process. The types of organic waste used in this study were raw sewage sludge, food wastewater leachate and livestock excretions. The biomethane potential was determined through the BMP test. The results showed that the biomethane potential of the livestock excretions was the highest at $1.55m^3CN4/kgVS$, and that the highest value of the composite sample, containing primary sludge, food waste leachate and livestock excretions at proportions of 50%, 30% and 20% respectively) was $0.43m^3CN4/kgVS$. On the other hand, the optimal mixture ratio of composite sludge in the demonstration plant was 68.5 (raw sludge) : 18.0 (food waste leachate) : 13.5 (livestock excretions), which was a somewhat different result from that obtained in the BMP test. This difference was attributed to the changes in the composite sludge properties and digester operating conditions, such as the retention time. The amount of biogas produced in the single-phase anaerobic digestion process was $2,514m^3/d$ with a methane content of 62.8%. Considering the value of $2,319m^3/d$ of biogas produced as its design capacity, it was considered that this process demonstrated the maximum capacity. Also, through this study, it was shown that, in the case of the anaerobic digestion process, the two-phase digestion process is better in terms of its stable tank operation and high efficiency, whereas the existing single-phase digestion process allows for the improvement of the digestion efficiency and performance.

• Journal of Embryo Transfer
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• v.30 no.2
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• pp.73-82
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• 2015

This study was designed to evaluate the possibility of increase through dairy female offspring's ratio by transfer of pre-selected transferrable blastocyst that was produced by pre-selected X-bearing semen with OPU derived oocytes. Elite dairy female cow is demanded strongly compared with male, the so called, farmer wants to produce only an elite female dairy offspring as a candidate female dairy cow for producing milk. In our study, we selected 2 elite dairy bull semen from National Agricultural Cooperative Federation to pre-select X-bearing semen and 5 elite dairy female cows as donor for collecting of OPU derived oocytes. OPU derived embryo production system was carried out an aspiration of immature oocytes from 5 donor cows 2 times per week, total 200 times for 2 to 7 months by an ultrasonographic guided follicular aspiration system and then produced in vitro-produced blastocysts by in vitro maturation, fertilization and culture. Dairy donor semen selected H-319, 320 bull in National Agricultural Cooperative federation was sorted X-bearing semen by flow-cytometer and frozen for using IVF with OPU derived oocytes. Donor cows were selected 5 elite dairy cows from Gyeongju Dairy Cow Community and then disease tests such as 4 kinds of disease before selecting was checked. Oocyte proportion of grade 1 to 3 from total collected oocytes was significantly lower in donor A and B than those in donor C, D and E (82.16 and 70.03% vs. 90.0, 91.78 and 93.57%), respectively (p<0.05). However, number of oocytes per session in donor A, C and E was significantly higher than those in donor B and D ($7.77{\pm}3.26$, $5.85{\pm}2.10$ and $7.03{\pm}2.14$ vs. $4.68{\pm}2.61$ and $5.21{\pm}1.97$ oocytes), but donor A was significantly higher than donor C (p<0.05). Development to blastocyst in donor B, C and E was significantly higher than those in donor A and D (31.0, 25.0 and 25.0% vs. 14.3 and 4.5%), but donor A was not different in donor C and E (p<0.05). Nine out of 10 blastocysts (90.0%) derived from OPU blastocysts were confirmed male embryos that was induced with Y-bearing semen to confirm sex ratio only. Total 96 blastocysts derived from female bearing semen were transferred into synchronized recipients and then confirmed 42 recipients (43.8%) pregnancy rate, 36 offspring (37.5%) and 91.7% female sex ratio (33 female vs. 3 male offspring). Taken together all data, elite dairy female offspring could be produced effectively by in vitro production system between pre-selected x-bearing semen and OPU derived oocytes that would be influential breeder in the breeding of dairy farm to increase effectively elite dairy offspring ratio as well as net income in the dairy farmer.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.151-158
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• 2010

This study was conducted to evaluate the feed value and growth characteristics of Sasa quelpaertensis Nakai by horse grazing in the woodland of Jeju. Crude protein (CP), NDF, ADF and minerals contents at different growth stages of Sasa quelpaertensis were analyzed. The apparent digestibilities of DM, CP, NDF and ADF were determined by total collection method using 5 Jeju horses. The yield and growth characteristics of S. quelpaertensis Nakai by horse grazing were investigated. CP contents in the currentand the previous-year-sprouted leaves of S. quelpaertenisis were $16.6{\pm}1.0%$ and $12.2{\pm}1.1%$, respectively. The digestibility of DM, CP, NDF and ADF in the current-year-sprouted leaves of S. quelpaertenisis were $47.2{\pm}1.2$, $67.8{\pm}1.0$, $47.0{\pm}1.3$ and $47.1{\pm}1.1%$, respectively. The current-year-sprouted S. quelpaertenisis tended to have high nutritional values and digestibilities compared to those of the previous-year-sprouted. The dry matter yield, plant length, leaf width and density of S. quelpaertensis Nakai were clearly decreased by horse grazing. These results show that considering the feed value and growth characteristics, the natural S. quelpaertenisis Nakai can be used as a feed source for horses.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.117-122
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• 1999

Purpose : We studied the correlation between urinalysis and radiologic findings in infants and children with urinary tract infection. Method : Urine Dipstick test and unstained urine microscopic examination were carried out in 56 infants and children who were hospitallized with the diagnosis of urinary infection by pocitive urine culture at Seoul Adventist from September 1996 through August 1998. Urine was collected by midsream, catheter, urine bag after cleansing or bladder puncture. Renal sonography and $^{99m}Tc-DMSA$ renal scan or voiding cystoureterography were studied. Results : 1)In dipstick analysis, leukocyte esterase(LE) were positive in 30 cases of 56 patients(54%) and Nitrite were positive in 20 cases of 56 patients(36%) and LE or Nitrite were positive in 38 cases of 56 children with UTI(68%). 2)In microscopic analysis, WBC were positive in 38 cases of patients(68%) and bacteria were positive in 23 cases of 56 patients(41%) and WBC or bacteria were positive in 41 cases of 56 children with UTI(71%). 3)Ten cases of 56 UTI patients(18%) showed negative finding in Dipstick and microscopic analysis. 4)There was no significant difference in positive rate of dipstick(71% vs 66%) and microscopia analysis(83% vs 66%) between two group with or without renal scar on $^{99m}Tc-DMSA$ scan (P=0.117). 5)There was no significnt difference in positive rate of dipstick(100% vs 91%) and microscopic analysis(100% vs 100%) between two groups with or without vesicoureteral reflux on VCUG. Conclusion : There was no specific relationships between the abnormal urinalysis and the abnormal findings on $^{99m}Tc-DMSA$ scan or VCUG.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.811-817
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• 2009

Purpose : Inhaled corticosteroids (ICS) are used as first-line agents for the treatment of persistent asthma; however, their use is accompanied by apprehension of potential systemic adverse effects. This study aimed to assess the effects of ICS on bone mineral density (BMD) and bone metabolism in children with asthma. Methods : From February 2008 to September 2008, 26 asthmatic children treated with ICS (ICS group), 15 asthmatic children treated with leukotriene receptor antagonist (LTRA) (LTRA group), and 30 healthy children (Control group) were selected from the Korea University Anam Hospital. BMD and serum bone-specific alkaline phosphatase (BALP) levels were measured. The asthmatic children underwent spirometry and methacholine bronchial challenge test. Results : There were no significant differences in BMD in the lumbar spine (P=0.254) and proximal femur (P=0.297) among the 3 groups. The serum BALP levels were significantly higher in both the ICS (P=0.017) and LTRA (P=0.025) groups than in the Control group. None of the parameters pertaining to ICS use, such as the mean daily dose during the last 6 months, the total cumulative dose, duration of use, and age of commencement of use, showed significant correlations with BMD (P>0.05 for all parameters). Conclusions : We demonstrated that a low dose of ICS does not exert any significant adverse effect on bone metabolism in asthmatic children. These findings support the current recommendations with regard to the use of ICS for asthmatic children.

• Development and Reproduction
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• v.12 no.1
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• pp.77-86
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• 2008

This study was carried out to investigate the effect of leukemia inhibitory factor (LIF) on the derivation of mouse ES cells from isolated blastomeres. Two-cell stage mouse embryos were obtained from superovulated BDF1 female mice. Collected embryos were cultured to blastocyst stage in culture medium supplemented with 0, 1,000, 2,500 or 5,000 U/mL of LIF. Cultured blastocysts were examined by counting the number of cells in the inner cell mass (ICM) and trophectoderm (TE) using differential staining method. When 2-cell embryos were cultured with 2,500 U/ml of LIF, the cell numbers of ICM significantly increased in comparing with those of the control($21.0{\pm}4.0$ vs. $15.9{\pm}5.0$, P<0.01) and 1,000 U/mL of LIF-containing group ($21.0{\pm}4.0$ vs. $16.6{\pm}4.9$, P<0.05). We used an ES cell establishment medium with 20% Knockout Serum Replacement and 0.01 mg/mL ACTH instead of fetal bovine serum. Establishing efficacy of ES cell lines were the highest in 2,500 U/mL of LIF-containing group as 36.7% (11/30). This culture medium was applied to the culture of isolated blastomeres and to derivate ES cell lines. Three ES cell lines (21.4%) from isolated blastomeres of 2-cell stage embryos were established. In further experiments, we could establish one ES cell line (4.0%) from single blastomere of 4-cell stage embryo. The subcultured ES cells and their embryoid bodies were characterized by analyzing gene expression for undifferentiation and differentiation marker gene using immunocytochemistry and RT-PCR. In conclusion, LIF supplementation in culture medium could increase the cell number in ICM of blastocysts and support derivation of ES cell lines from isolated blastomeres.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.419-425
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• 2006

Background : Severe community-acquired pneumonia (CAP) can develop into respiratory failure that requires mechanical ventilation (MV), which is associated with a higher rate of mortality. It was recently reported that a hydrocortisone infusion in severe CAP patients was associated with a significant reduction in the length of the hospital stay and mortality. This study evaluated efficacy of a hydrocortisone infusion for patients with severe CAP requiring MV. Methods : From February 2005 to July 2005, 13 patients (M : F = 10 : 3, mean age: $68.6{\pm}14.1years$), who were diagnosed with severe CAP and required MV, were enrolled in this study. Hydrocortisone was administered as an intravenous 200mg loading bolus, which was followed by an infusion at a rate of 10mg/hour for 7 days. The control group was comprised of patients with severe CAP requiring MV but in whom corticosteroid was not used before study period. The clinical and physiologic parameters on or by day 8 and the outcome in the hydrocortisone infusion group were compared with those in the control group. Results : 1) There was no significant difference in age, gender ratio, SAPS II, SOFA score, temperature, leukocyte count, PaO2/FiO2 (P/F) ratio, the number of patients with P/F ratio < 200, chest radiograph score, lung injury score and catecholamine-dependent septic shock between the hydrocortisone infusion group and control group at day 1. 2) At day 8, the proportion of patients with an improvement in the P/F ratio ${\geq}100$ and the chest radiograph score was significantly higher in the hydrocortisone infusion group than in the control group (61.5% vs. 15.4%, 76.9% vs. 23.1%, p< 0.05). However, there was no significant difference in the other clinical and physiologic parameters. 3). There was no significant difference in the duration of the MV, ICU stay, hospital stay and 10th and 30th day mortality between the two groups. Conclusion : Hydrocortisone infusion for patients with severe CAP requiring invasive mechanical ventilation may be effective in improving the level of oxygenation and the chest radiograph score.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.310-314
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• 2009

Purpose : Pneumothorax is an important factor responsible for increased mortality and morbidity in neonates. Here, we compared the clinical findings and prognosis for neonatal pneumothorax induced by respiratory distress syndrome (RDS) and pneumonia. Methods : Between January 2001 and December 2005, 80 patients with neonatal pneumothorax induced by RDS and pneumonia and admitted to the NICU of Dongsan Medical Center, Keimyung University, were enrolled. They were assigned to the RDS group (30 cases) or the pneumonia group (50 cases). Admission records for gestational age, onset day of life, rate of ventilatory care and thoracostomy, and prognosis were retrospectively reviewed and statistically analyzed for both groups. Results : The mean gestation age was significantly shorter in the RDS group (32.3 weeks) than in the pneumonia group (38.1 weeks) (P<0.001), and the mean onset day of life were later in the RDS group (4.6 days) than in the pneumonia group (1.8 days) (P<0.05). Rates of ventilatory care and thoracostomy were higher for the RDS group than for the pneumonia group (100% vs. 44%, and 66.7% vs. 48%, respectively). Total mortality rates and pneumothorax specific mortality rates were higher for the RDS group than for the pneumonia group (46.7% vs. 18%, P<0.01 and 33.3% vs. 16%, P<0.05, respectively). After logistic regression analysis, preterm significantly increased the mortality rate (OR 7.44, 95% CI: 1.99-27.86, P<0.005), but bilateral involvement (OR 1.17, 95% CI: 0.82-1.67, P>0.5) and the RDS group itself (OR 1.70, 95% CI: 0.52-5.54, P>0.3) did not increase mortality rates significantly. Conclusion : Our study suggests that neonatal pneumothorax in the RDS group tends to have a later onset, higher mortality rate, and needs a higher rate of thoracostomy than the pneumonia group. However, after logistic analysis, only preterm significantly and independently increased the mortality rate.

• Clinical and Experimental Pediatrics
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• v.51 no.12
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• pp.1336-1341
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• 2008

Purpose : This study aimed to determine the frequencies of $CD4^+CD25^+$ T cells in donor graft and peripheral blood $CD4^+CD25^+$ T cells in recipients after hematopoietic stem cell transplantation (HSCT) and their association with graft-versus-host disease (GVHD). Methods : Seventeen children who underwent HSCT were investigated. $CD4^+CD25^+$ T cells in samples from donor grafts and recipient peripheral blood were assessed by flow cytometry at 1 and 3 months after transplantation. Results : $CD4^+CD25^+$ T cell frequencies in the grafts showed no significant difference between patients with and without acute GVHD (0.90% vs. 1.06%, P=0.62). Absolute $CD4^+CD25^+$ T cell number in grafts were lower in patients with acute GVHD than in those without acute GVHD ($6.18{\times}10^5/kg$ vs. $25.85{\times}10^5/kg$, P=0.09). Patients without acute GVHD showed a significant decrease in peripheral blood $CD4^+CD25^+$ T cell percentage at 3 months compared to those at 1 month after HSCT (2.11% vs. 1.43%, P=0.028). However, in patients with acute GVHD, $CD4^+CD25^+$ T cell percentage at 3 months was not different from the corresponding percentage at 1 month after HSCT (2.47% vs. 2.30%, P=0.5). Conclusion : The effect of frequencies of $CD4^+CD25^+$ T cells in donor grafts on acute GVHD after HSCT could not be identified, and the majority of peripheral blood $CD4^+CD25^+$ T cells in patients who underwent HSCT may be activated T cells related to acute GVHD rather than regulatory T cells. Further studies with additional markers for regulatory T cells are needed to validate our results.