소형 트럭용 CNG/가솔린 겸용 엔진 개발과 성능 분석

권오운,김재수,박용국,김성준 江原大學校 産業技術硏究所 2006 産業技術硏究 Vol.26 No.B

A diesel truck of 1 ton is re-powered by a gasoline engine and the fuelling system of gasoline engine is modified to gasoline/CNG bi-fuel system. The engine characteristics such as fuel economy and power are evaluated by driving test, sloping test and dynamometer. The driving test prove the driving cost is saved by 55% and the maximum speed is raised by 13%, which is mainly due to the higher calorific value of CNG. The sloping test is done on thc road of which slope is 15%. The truck shows the mean velocity of 88km/h, which means that are-powered truck is working fine. The BHP are measurcd by dynamomcter. The-power and torque produced by a re-powered truck are reduced by 13% and 14% respectively from the power of gasoline engine. The BHP reduction is one of main problems which one has to solve in near future.

파라콰트 중독에서의 항산화치료

권운용,조유환,송형곤,김명천,이중의,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Paraquat causes severe tissue toxicity when ingested, but has no effective treatment modality. We have shown that high dose vitamin C has effective antioxidant activities against the paraquat intoxication in a previous animal experiment. This study was designed to evaluate the effect of antioxidant therapy with high dose vitamin C and vitamin E in human cases of paraquat intoxication. Methods: From August 1999 to August 2001, 19 paraquat intoxication patients who visited the emergency department of the Seoul National University Hospital and the Kyounghee University Hospital were enrolled to this study. They were devided into two groups, a control group(9 patients) and a study group(10 patients). The control group received only conservative managements including gastro-intestinal decontaminati-on. The study group received conservative managements plus the antioxidant therapy which was composed of vitamin C 24 gm/day intravenously and 20 gm/day orally, and vitamin E 1.6 gm/day orally. Results: In the study group, 5 of 10 patients(50%) survived, but all patients of the control group died(p=0.003). There were no significant differences in age, sex, and usage of gastric lavage and activated charcoal between the two groups. Difference in ingested amount of paraquat between the two groups could not be analyzed due to the inexact and subjective measuring methods based on patients' histories. Conclusion: Antioxidant therapy with high dose vitamin C and vitamin E is effective in vival rate in paraquat intoxicated patients.

씨름선수에서 체중 감량과 회복기의 Leptin과 PAI-1 변화

김용운,도경오,권태동,박덕일,장응찬,박소영,김종연,이석강 대한스포츠의학회 2000 대한스포츠의학회지 Vol.18 No.2

Obesity which is defined as accumulation of excess body fat, is central factor of insulin resistance syndrome. Recently, it is revealed tat adipose tissue is not simply an energy storage organ but it also secretes a variety of molecules which affect the metabolism of the whole body, those are leptin and plasminogen activator inhibitor-1(PAI-1). Therefore, leptin and PAI-1 are increased in the obese state. Leptin regulates energy homeostasis and satiety and PAI-1 regulates fibrinolytic system. For these reasons, elevated levels of leptin and PAI-1 are considered as link factors between obesity and insulin resistance syndrome. However, the exact regulating mechanism for serum levels of leptin and PAI-1 is not fully understood yet. In this study, to evaluate the regulating mechanisms of serum levels of leptin and PAI-1 according to the weight changes, we measured leptin, PAI-1, physical, metabolic, and endocrine parameters during 10 days of weight reduction and 10 days of regain period in 7 young athletes. The mean body weight change was -4.7 kg(5.0%) in the weight reduction period and -2.4 kg(2.5%) in the weight regain period compared to baseline value. Baseline level of leptin in athletes was 1.7±0.66 ng/ml, which was significantly correlated with body weight, BMI, percent body fat, body fat mass, triglyceride, insulin, and PAI-1. Baseline level of PAI-1 in athletes was 16.6±5.26 ng/ml, which was significantly correlated with body weight, BMI, triglyceride, insulin, and leptin. Leptin was decreased to 0.7±0.39(44% of the basaline value) in the weight reduction period, and increased to 1.9±0.64(119% of the baseline value) in the regain period. PAI-1 was decreased to 7.4±2.72(44% of the basaline value) in the weight reduction period, and increased to 22.8±7.33(138% of the baseline value) in the regain period. The changes of leptin during weight reduction period were significantly correlated with the changes of insulin(r=0.890, P<0.01) and triglycerides(r=0.874, P<0.01). The changes of PAI-1 during weight reduction period were significantly correlated with the changes of FFA(r=0.889, P<0.01) and triglycerides(r=0.869, P<0.05). The changes of both leptin and AAI-1 during weight regain period were significantly correlated with the changes of insulin(r=0.755 and 0.849, P<0.05, respectively). In summary, these results suggest that serum levels of leptin and PAI-1 were affected by weight cycling, the percentages of change were more greater than that of weight change, and rebound phenomena were occurred during weight regain period.

대장암 환자에서의 담즙 암태아성 항원(CEA)

김종우,박용태,정철운,권성원,장항석,손석우,안대호,이경포 대한대장항문학회 2000 Annals of Coloproctolgy Vol.16 No.6

발열이 있는 호중구 감소증 환자에서의 위험도 예측인자

정중식,권운용,김규석,임용수,이중의,서길준,윤여규 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Most febrile neutropenic patients are treated in an aggressive manner. However, identification of low-risk patients may enable clinicians to administer risk-based treatment. The object of this study is to certify the factors associated with increased risk at the time of visiting the emergency department. Methods: This is a retrospective study. We reviewed the medical records of 101 febrile neutropenic patients who had visited the emergency department of Seoul National University Hospital from January 1998 to August 1999. We assumed 22 risk prediction factors that could be assessed at admission to the emergency department and 5 factors that could be assessed during treatment course. To find independent risk-prediction factors, we analyzed these factors respectively by using multiple regression analysis. Results: Tachycardia(aOR=136.5), altered mentality(aOR=28.8), decreased renal function(aOR=20.1), and significant comorbidity(aOR=17,2) are the independent factors associated with higher mortality. Altered mentality(aOR=31.6) and decreased renal function(CCr < 75㎖/min, aOR=5.4) are those associated with a higher incidence of septic shock. Independent factors associated with persistent(more than 3 days) fever are the early(within 10 days) onset of fever after last chemotherapy(aOR=8.8) and the existence of new pulmonary infiltrates on a simple chest X-ray(aOR=4.3). Conclusion: The stability of vital signs, the change of mentality, the renal function, the existence of significant comorbidity, the existence of new pulmonary infiltrates, and the rate of neutropenia are clinically useful risk-prediction factors in febrile neutropenia at the time of visiting the emergency department.

만화 과제를 이용한 정신분열병 환자의 사회인지 능력의 측정

오정은,나명현,하태현,신용욱,노규식,홍순범,이경진,신민섭,이영호,권준수 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.3

Objectives : This study is to investigate the hypothesis that schizophrenic patients have difficulty in inferring mental state of others. Methods : Twenty schizophrenic patients and twenty normal subjects were administered to the Cartoon Task required inferring the character's intention in a given context. Results : The schizophrenic patients showed a statistically significant impairment in the Cartoon Task. Both groups chose the card depicting a frequent everyday action significantly more rather than the similar card to the last picture in each story for wrong answers. Conclusion : These preliminary results suggest that schizophrenia is associated with a specific deficit of the cognitive ability referred to as social cognition, and this deficit can be detected not only in the acute phase as found in previous research studies, but also in remission. Also when subjects fail to appreciate what is going on in the minds of other people, they seem to rely on a socially familiar experience.

119구급대를 통한 서울지역 외상환자 진료체계에 대한 통계분석

서길준,이승한,조익준,권운용,송형곤,이중의,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.2

Backgroud: Despite continous efforts to improve the prehospital trauma care system in Korea, the preventable death rate has been reported to be high. The purpose of this study was to evaluate the prehospital trauma care system in Seoul by analyzing 119 rescue databases. Methods: The 119 rescue data bases of 22,275 trauma patients, who were transported to the secondary and tertiary hospital in Seoul by Seoul 119 rescue services from January 1, 2000 to December 31, 2000, were analyzed. Results: The response time(mean 3.7 min.) showed no time, weekly, and regional variations. However, the transport time from field to hospital showed was high in the morning rush hour(7:00 to 10:00 am), and was gradually decreased and the lowest between 10:00 pm and 7:00 am. There was also a regional variation in the transport time, which was short in the central area and long in the peripheral area of Seoul. Prehospital cares were given to the 10,999 trauma patients(49.4%). Of the 464 unresponsive patients(2%), only 236 patients were identified in transported hospitals. The outcomes of these unresponsive patients were DOA(54%), survival(19%), death in ER(14%), transfer to other hospitals(8%), and death after admission(5%) in order. Conclusion: We suggest that this study may be helpful to the establishment and improvement of the prehospital trauma care system as well as the determination of the adequate numbers and locations of trauma center in Seoul.

Conducting Polymer-Silica Composites for Immobilization of Enzymes

Kwon, Sang-Woon,Jeong, Bo-Ock,Lee, Eun-Hee,Kim, Yong-Shin,Jung, Yong-Ju Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

A new enzyme immobilization method based on hydrophobic interaction between supporting material and enzyme has been successfully developed. The efficacy of the new technique has been investigated by loading a horse radish peroxidase (HRP) enzyme on the surface of conducting polymer-silica composites and by measuring the enzyme activity and leaching property of HRP loaded within polymer-silica composites. The immobilized HRP enzyme showed activity profiles similar to that of free HRP in phosphate buffer (pH 6). Above all, HRP adsorbed on the polymer-silica composites has showed excellent stability over 10 days, compared to HRP adsorbed on the pristine silica. It is thought that with appropriate optimization works, the present method would be used as a cost-effective and facile route for the immobilization of biomolecules.

4F, apolipoprotein AI mimetic peptide, attenuates acute lung injury and improves survival in endotoxemic rats

Kwon, Woon Yong,Suh, Gil Joon,Kim, Kyung Su,Kwak, Young Ho,Kim, Kyuseok Lippincott Williams Wilkins, Inc. 2012 The journal of trauma and acute care surgery Vol.72 No.6

BACKGROUND: 4F, apolipoprotein AI mimetic peptide, mimics anti-inflammatory properties of high-density lipoprotein (HDL). The aim of this study was to investigate whether 4F attenuates acute lung injury and improves survival in endotoxemic rats and to determine whether the therapeutic benefits of 4F are associated with the stimulation of sphingosine-1-phosphate receptor 1 (S1P1), the activation of Akt, the down-regulation of the nuclear factor-&kgr;B (NF-&kgr;B) pathway, and the suppression of cell adhesion molecules. METHODS: To induce endotoxemia in rats, lipopolysaccharide (LPS, 10 mg/kg) was injected into a tail vein and 10 minutes later, vehicle or 4F (10 mg/kg) was administered intraperitoneally, respectively. We observed the survival of subjects for 72 hours. At 6-hour post-LPS, we killed animals and measured S1P1 expression, phosphorylated Akt/Akt ratio, cytoplasmic phosphorylated inhibitor &kgr;B-α/inhibitor &kgr;B-α ratio, nuclear NF-&kgr;B p65 expression and DNA-binding activity, endothelial leukocyte adhesion molecule-1 (E-selectin) and intercellular adhesion molecule-1 expression, myeloperoxidase activity, and histologic damages in lung tissues. We also measured serum HDL cholesterol level. RESULTS: 4F improved survival in endotoxemic rats. 4F restored LPS-induced diminution of serum HDL cholesterol level and increased lung S1P1 expression and phosphorylated Akt/Akt ratio in LPS-treated rats. Furthermore, 4F suppressed inhibitor &kgr;B-α degradation, NF-&kgr;B activation, E-selectin and intercellular adhesion molecule-1 expression, and myeloperoxidase activity, and attenuated histologic damages in lung tissues. CONCLUSIONS: 4F attenuated acute lung injury and improved survival in endotoxemic rats. The therapeutic benefits of 4F were found to be associated with the stimulation of S1P1, the activation of Akt, the down-regulation of the NF-&kgr;B pathway, and the suppression of cell adhesion molecules.

Niacin Suppresses the Mitogen-Activated Protein Kinase Pathway and Attenuates Brain Injury After Cardiac Arrest in Rats*

Kwon, Woon Yong,Suh, Gil Joon,Kim, Kyung Su,Lee, Hui Jai,Jeong, Ki Young,Kwak, Young Ho,Kim, Kyuseok by the Society of Critical Care Medicine and Lippi 2013 Critical care medicine Vol.41 No.9

OBJECTIVES:: To determine whether niacin attenuates brain injury and improves neurological outcome after cardiac arrest in rats and if its therapeutic benefits are associated with suppression of the mitogen-activated protein kinase pathway. DESIGN:: Prospective laboratory study. SETTING:: University laboratory. SUBJECTS:: Male Sprague-Dawley rats (n = 77). INTERVENTIONS:: After 6 minutes of no flow time induced by ventricular fibrillation, cardiopulmonary resuscitation was provided and return of spontaneous circulation was achieved. Animals were then administered vehicle, single low dose (360 mg/kg; at 1 hr postreturn of spontaneous circulation), single high dose (1080 mg/kg; at 1 hr), or repeated low dose of niacin (360 mg/kg/d for 3 d; at 1, 24, and 48 hr) through an orogastric tube. MEASUREMENTS AND MAIN RESULTS:: Neurologic deficit scales were scored at 24 hours, 72 hours, and 7 days postreturn of spontaneous circulation. Single high dose of niacin improved neurologic deficit scales at 48 hours and 7 days, and repeated low dose of niacin improved neurologic deficit scales at 7 days. Then, a separate set of animals were killed at 72 hours postreturn of spontaneous circulation, and brain tissues were harvested. Single high dose and repeated low dose of niacin attenuated cellular apoptosis and neuronal damage in hippocampal cornu ammonis 1 and decreased axonal injury and microglial activation in corpus callosum. They increased nicotinamide adenine dinucleotide, reduced nicotinamide adenine dinucleotide phosphate and reduced glutathione levels, and decreased malondialdehyde level in brain tissues. Furthermore, they suppressed the phosphorylations of p38 and c-Jun N-terminal kinase/stress-activated protein kinase and the cleavage of caspase 3. However, they failed to enhance extracellular signal-regulated kinases 1/2 phosphorylation. CONCLUSIONS:: Single high dose and repeated low dose of niacin attenuated brain injury and improved neurological outcome after cardiac arrest in rats. Their therapeutic benefits were associated with suppressions of the phosphorylations of p38 and c-Jun N-terminal kinase/stress-activated protein kinase and the cleavage of caspase 3.