• Journal of Chest Surgery
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• v.41 no.2
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• pp.149-159
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• 2008

Background: With increasing coronary bypass and peripheral vascular surgeries, the demand for homologous vascular or synthetic conduits has continued to grow, but wide-spread application has been limited by dismal patency rates. Although cryopreserved allograft valves may provide a suitable alternative, current viability or patency of implanted allograft vascular conduits has been unsatisfactory. Material and Method: We serially analyzed the outcomes of canine femoral artery and saphenous vein allograft implants after storage in either $4^{\circ}C\;or\;-170^{\circ}C$. Result: There were no differences in graft flow rate (patency) (p=0.264), rate of thrombosis (p=0.264), presence of endothelium (p=0.587), or immunohistochemical staining for thrombomodulin (p=0.657) were detected between grafts stored in $4^{\circ}C\;and\;-170^{\circ}C$. Greater flow occurred in the arterial grafts versus the venous grafts (p=0.030), irrespective of the preservation method, with a significantly lower incidence of thrombosis (p=0.030) in arterial allografts. There was a correlation coefficient of -0.654 between thrombosis and positive immunohistochemical staining for thrombomodulin (p=0.006) and a correlation coefficient of 0.520 (p=0.0049) between the endothelial presence and positive immunohistochemical staining for thrombomodulin. The relationship between the presence of endothelium and thrombomodulin expression failed to show any correlation within the first 2 weeks (p=0.306). However, a strong correlation was seen after 1 month (p=0.0008). Conclusion: Tissue storage in either $4^{\circ}C\;or\;-170^{\circ}C$ in 10% DMSO/RPMI-1640 preservation solution preserved grafts equally well. In terms of thrombosis and graft patency, arterial grafts were superior to venous grafts. Considering the poor correlation between thrombomodulin expression and the presence of an endothelium in the implanted graft within the first two weeks, grafts in this period would not be thromboresistant.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.121-128
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• 1998

Ochratoxin A (OA) is a mycotoxin produced by Aspergillus ochraceus as well as other molds. It is a natural contaminant of mouldy food and feed. OA has a number of toxic effects, the most prominant being nephrotoxicity. Futhermore, OA is immunosuppressive, genotoxic, teratogenic and carcinogenic. OA inhibits protein synthesis by competition with phenylalanine in the phenylalanine-tRNA aminoacylation reaction. Recently, lipid peroxidation induced by OA has been reported, indicating that the lesion induced by this mycotoxin could be also related to oxidative pathway. Since it seems impossible to avoid contamination of foodstuffs by toxigenic fungi, detoxification and detoxication of OA are needed. In this study we investigated the protective effects of aspartame (Asp), phenylalanine (Phe), polyphenol 70S (PP) and aloe extract (AE) on the nephrotoxicity induced by subacute exposure to the OA. Asp and Phe are structural analogues of OA. PP, an ingredient of Green Tea and AE have been known as antioxidant and radical scavenger. Phe (40 mg/kg, i.p.) and Asp (25 mg/kg, p.o.) were administered to Sprague-Dawley rats simultaneously with OA (2.0 mg/kg, p.o.) for 2 weeks. PP (200 mg/kg, p.o.) and AE (50 mg/kg, i.v.) were pretreated before administration of OA, for 2 weeks and 3 days, respectively. Using enzymuria, BUN level, creatinemia and histophathologic examination as indices of renal damage, we observed that all of four compounds prevented the nephrotoxic effects induced by OA. It seems that structural analogues of OA such as Asp and Phe have better protective effect on the nephrotoxicity of OA than antioxidants. These results indicate that 1) formation of free radical and lipid peroxidation are likely to be involved in the nephrotoxicity of OA in vivo, 2) Asp, PP and AE might be used for prevention of renal lesions in cases of ochratoxicosis.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.108-118
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• 1999

Background: To evaluate the risk factor and long-term result of arterial switch operation , a retrospective study was done. Material and Method: A retrospective analysis was done to evaluate the early and long-term results on 58 patients who underwent an arterial switch operation(ASO) for transposition of the great arteries(TGA) with intact ventricular septum, between January 1988 and December 1996. Beforesurgery, 36 patients(62.1%) underwent balloon atrial septostomy, 32 patients(51.7%) received PGE1 infusion, and preparatory banding of pulmonary artery was performed on 6 patients(mean LV/RV pressure ratio 0.53$\pm$0.11). Result: The age at operation ranged from 1 to 137 days(mean 24$\pm$26 days) and the weights ranged from 1.8 to 6.8 kg (mean 3.5$\pm$0.8 kg). There were 14 early deaths(24.1%), but of the last 24 patients operated on since 1994, there were only 2 early deaths(8.3%). In the risk factor analysis, the date of operation was the only risk factor for early death(p-value < 0.01). Eight of the 14 early deaths were due to acute myocardial failure(mainly inadequate coronary blood flow). The length of follow-up ranged from 2 months to 8 years, average of 36$\pm$27 months. The follow-up included sequential noninvasive evaluations and 21 catheterizations and angiographic studies performed 5 to 32 months postoperatively with particular attention to the great vessel and coronary anastomosis, ventricular function, valvular competence, and cardiac rhythm. There were 5 late deaths(11.4%), one of thesedeaths was related to the late coronary problems, two to aspiration, one to uncontrolled chronic mediastinitis, and one to progressive aortic insufficiency and heart failure. The most frequent postoperative hemodynamic abnormality was supravalvular stenosis and the degree of pulmonary or aortic obstruction had slowly progressed in some cases, however there were no children who had to undergo a reoperation for supravalvular pulmonary or aortic stenosis. Aortic regurgitation was identified in 9 patients, which was mild in 7 and moderate in 2 and had progressed in some cases. Two patients who had an unremarkable perioperative course were identified as having coronary artery obstructions. The other late survivors were in good condition, were in sinus rhythm, and had normal LV functions. Actuarial survival rate at 8 years was 68.8%. Conclusion: We concluded that anatomic correction will be established as the optimal approach to the TGA with intact ventricular septum, though further long-term evaluations are needed.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.17-30
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• 2020

In the shipping industry, it is essential to engage in the preemptive prediction of freight rate volatility through market monitoring. Considering that freight rates have already started to fall, the loss of shipping companies will soon be uncontrollable. Therefore, in this study, factors affecting the freight rates of bulk carriers, which have relatively large freight rate volatility as compared to container freight rates, were quantified and analyzed. In doing so, we intended to contribute to future shipping market monitoring. We performed an analysis using a vector error correction model and estimated the influence of six independent variables on the charter rates of bulk carriers by Handy Size, Supramax, Panamax, and Cape Size. The six independent variables included the bulk carrier fleet volume, iron ore traffic volume, ribo interest rate, bunker oil price, and Euro-Dollar exchange rate. The dependent variables were handy size (32,000 DWT) spot charter rates, Supramax 6 T/C average charter rates, Pana Max (75,000 DWT) spot charter, and Cape Size (170,000 DWT) spot charter. The study examined charter rates by size of bulk carriers, which was different from studies on existing specific types of ships or fares in oil tankers and chemical carriers other than bulk carriers. Findings revealed that influencing factors differed for each ship size. The Libo interest rate had a significant effect on all four ship types, and the iron ore traffic volume had a significant effect on three ship types. The Ribo rate showed a negative (-) relationship with Handy Size, Supramax, Panamax, and Cape Size. Iron ore traffic influenced three types of linearity, except for Panamax. The size of shipping companies differed depending on their characteristics. These findings are expected to contribute to the establishment of a management strategy for shipping companies by analyzing the factors influencing changes in the freight rates of charterers, which have a profound effect on the management performance of shipping companies.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.763-773
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• 1996

Background : Behçet's syndrome is a chronic multisystemic disease affecting many organs such as skin, mucosa, eye, joint, central nervous system and blood vessels. Lung involvement occurs in 5% of Behçet's syndrome and is thought to be due to the pulmonary vasculitis leading to thromboembolism, aneurysm and arteriobronchial fistula. Pulmonary vasculitis in Behçet's syndrome is a unique clinical feature, differing from other vasculitis affecting the lung and is one of the major causes of death. Therefore, we examined the incidence, the clinical features, the radioloic findings and the clinical courses of the lung involvement in Behçet's syndrome. Methods: We retrospectively reviewed the medical records and radiologic studies of 10 cases of the lung involvement in Behçet's syndrome diagnosed at Yongdong Severance Hospital and Severance Hospital from 1986 to 1995. We analysed the clinical features, the radiological findings, the treatment modalities and the clinical courses. Results: 1) The incidence of the lung involvement in Behçet's syndrome was 2%(10/487). The male to female ratio was 8 : 2 and the mean age was 34 years. The presenting symptom was hemoptysis in 5 of 10 cases, and massive hemoptysis was noted in 2 cases. Other pulmonary symptoms were cough(6/10), dyspnea(4/10), and chest pain(2/10). Other manifestations were oral ulcers(10/10), genital ulcers(9/10), skin lesions(7/10), and eye lesions(6/10). 2) The laboratory findings were nonspecific. The posteroanterior views of chest radiographies showed multiple infiltrates(6/10), nodular or mass-like opacities(4/10), or normal findings(2/10). The chest CT scans showed multifocal consolidations(6/8), and aneurysms of the pulmonary aneries(4/8). The pulmonary angiographies were performed in 3 cases, and showed pulmonary artery aneurysms in 2 cases. The ventilation-perfusion scans in 2 cases of normal chest x-ray showed multiple mismatched findings. 3) The patients were treated with combination therapy consisting of corticosteroids, cyclophosphamide, and colchicine or anticoagulant agents. Surgical resection was performed in one case with a huge aneurysm. 4) We have followed up nine of ten cases. Three cases are well-being with medical therapy, two cases are severely disabled now and four cases died due to massive hemoptysis, massive pulmonary embolism, or sepsis. Conclusion : Pulmonary vasculitis is a main feature of the lung involvement of Behçet's syndrome, causing hemorrhage, aneurysmal formation, and/or thromboemboism. The lung involvement of Behçet's syndrome is uncommon but is one of the most serious prognostic factors of the disease. Therefore, an aggressive diagnostic work-up for early detection and proper treatment are recommended to improve the clinical course and the survival.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.459-465
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• 2002

To obtain the basic data for commercial 10% salted egg yolk for mayonnaise preparation, 3 types of egg yolks [pasteurized egg yolk (Yolk A)-not salted, pasteurized before salting (Yolk B)-salted, and pasteurized after salting (Yolk C)-salted] were prepared, and the changes in quality characteristics of these egg yolks with frozen storage were tested. The results obtained were as follows; Yolk A gelatinized during frozen storage, thus could not used for mayonnaise preparation. The viscosity of the egg yolk increased $3{\sim}5$ times after salting. Viscosity of the salted egg yolk increased with frozen storage time. Viscosity of Yolk B was higher at $-20^{\circ}C$ than $-15^{\circ}C$. Viscosity of Yolk C, however, was higher at $-15^{\circ}C$ than $-20^{\circ}C$. Frozen storage of pasteurized salted egg yolk showed some effects on the emulsification capacity. The effect, however, was smaller than that of unpasteurized salted egg yolk. Microbes of salted egg yolk were decreased with frozen storage, but there was no difference between Yolk B and Yolk C. It was suggested that commercially pasteurized 10% salted egg yolk for mayonnaise preparation can be successfully stored for 12 months at the temperature of $-15{\sim}-20^{\circ}C$.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.762-767
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• 2004

With the developement of non-invasive surgical techeniques, coronary artery bypass graft without cardiopulmonary bypass has become popular. We compared the preoperative risk factors and in-hospital outcomes of patients having off-pump CABG with these having on-pump CABG. Material and Method： From January 2001 to June 2003, 87 patients underwent CABG. Thirty-sin patients underwent on-pump CABG, fifty-one patients under-went off-pump CABG. Preoperative risk factors, extent of coronary disease, operative time, postoperative endotracheal intubation time, duration of ICU stay & hospital stay, the amount of bleeding and postoperative levels of cardiac enzymes were compared in both groups, Result: The were no differences in their sex ratios, ages, preoperative risk factors, preoperative Ml, Canadian classes, extent of coronary artery diseases and, echocardio-graphic ejection fraction between Off-pump CABG and On-pump CABG groups. Off-pump CABG group had significantly lower mean operative time (270$\pm$79.3 min vs 372$\pm$142.2 min, p＜0.001), mean ventilation time (17.1$\pm$13.4 hr vs 24.3$\pm$17.8 hr) and CK-MB level (8,9$\pm$18.7 IU/L vs 25.7$\pm$8.4 IU/L) than on-pump CABG groups, On-pump CABG group had more distal grafts (2.2$\pm$0.5 vs 1.7$\pm$0.71 than Off-pump CABG groups did. There were no differences in their postoperative complications and outcomes including amount of postoperative bleeding for 24 hrs, reoperation for bleeding control, mean in-hospital days, postoperative infection, renal failure and neurologic complications between Off-pump CABG and On-pump CABG groups. Conclusion: This study showed that patients who underwent Off-pump CABG had less operation time & intubation time and lower CK-MB level; however, they also have less distal graft. Even though CABG without CPB provided satisfactory results, more clinical experience & longer follow-up is required.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.85-96
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• 2019

Solar radiation is an important variable for estimation of energy balance and water cycle in natural and agricultural ecosystems. A deep neural network (DNN) model has been developed in order to estimate the daily global solar radiation. Temperature and precipitation, which would have wider availability from weather stations than other variables such as sunshine duration, were used as inputs to the DNN model. Five-fold cross-validation was applied to train and test the DNN models. Meteorological data at 15 weather stations were collected for a long term period, e.g., > 30 years in Korea. The DNN model obtained from the cross-validation had relatively small value of RMSE ($3.75MJ\;m^{-2}\;d^{-1}$) for estimates of the daily solar radiation at the weather station in Suwon. The DNN model explained about 68% of variation in observed solar radiation at the Suwon weather station. It was found that the measurements of solar radiation in 1985 and 1998 were considerably low for a small period of time compared with sunshine duration. This suggested that assessment of the quality for the observation data for solar radiation would be needed in further studies. When data for those years were excluded from the data analysis, the DNN model had slightly greater degree of agreement statistics. For example, the values of $R^2$ and RMSE were 0.72 and $3.55MJ\;m^{-2}\;d^{-1}$, respectively. Our results indicate that a DNN would be useful for the development a solar radiation estimation model using temperature and precipitation, which are usually available for downscaled scenario data for future climate conditions. Thus, such a DNN model would be useful for the impact assessment of climate change on crop production where solar radiation is used as a required input variable to a crop model.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.44-52
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• 2010

The objective of this in vitro study was to detect and monitor demineralization and remineralization of primary teeth according to restorative materials using quantitative light-induced fluorescence (QLF). A single bur hole was drilled on the each sound forty eight primary anterior teeth, and the specimens were divided into three groups. The cavity was restored with $Filtek^{TM}$ Z250(Group 1), F2000(Group 2), $Ketac^{TM}$ N100(Group 3) following the manufacturer's instructions. The teeth were subjected to the demineralizing buffer for 3 days, and then subjected to a remineralizing buffer for 14 days. The change of mineral loss(${\Delta}Q$) according to the stages was evaluated by QLF and the following results were obtained: 1. When demineralization was done, ${\Delta}Q$ was increased as follows. : Group 1 ($-110.79\;{\pm}\;27.77$) < Group 2 ($-104.84\;{\pm}\;28.95$) < Group 3 ($-90.16\;{\pm}\;21.87$) : Resistance to demineralization was statistically significant in Group 3. 2. There was a statistically significant increase in ${\Delta}Q$ of all groups since 1st day of remineralization 3. The rate of remineralization, ${\Delta}$(${\Delta}Q$)/day, showed significant high value in each group on the 1st day then decreased rapidly. 4. There was no statistically significant difference in the degree of remineralization among restorative materials.