Methane의 CO₂ Reforming 반응에 대한 Pt/Ce_(x)Zr_(1-x)O₂(x=0, 0.5, 1)의 환원-산화특성과 반응성

김유철,김기석 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.2

CeO_(2), Ce_(0.5)Zr_(0.5)O_(2), Zr_(2)에 각각 0.5wt%의 백금을 담지시킨 촉매의 환원-산화특성과 CH_(4)의 CO_(2) reforming에 대한 반응성간의 상관관계를 조사하였다. 촉매의 환원-산화 특성은 600℃에서의 CO-O_(2) 및 CO-CO_(2) cyclic pulse 실험에 의하여 Pt/Ce_(0.5)Zr_(0.5)O_(2)>Pt/CeO_(2)>>Pt/ZrO_(2)의 순서를 나타낸 반면, CH_(4)의 CO_(2) reforming 반응성은 550-650℃에서 양론비로 혼합된 CH_(4)과 CO_(2) pulse에 대하여 Pt/ZrO_(2)>Pt/Ce_(0.5)Zr_(0.5)O_(2)>Pt/CeO_(2)의 순서를 타나내었다. 상대적으로 비환원성인 Pt/ZrO_(2)가 Pt/Ce_(0.5)Zr_(0.5)O_(2)또는 Pt/CeO_(2)와는 다른 반응기구를 따른다는 것을 알 수 있었다. Pt/ZrO_(2)는 처음부터 일정한 수준의 반응성을 나타낸 반면, Pt/Ce_(0.5)Zr_(0.5)O_(2)와 Pt/CeO_(2)는 촉매의 환원 상태에 따라서 반응성이 변화하였다. Pt/Ce_(0.5)Zr_(0.5)O_(2)는 높은 산소 유동성 때문에 반응초기에는 CH_(4)의 완전산화 반응이 오히려 지배적이었으나, 반응기체 pulse 주입 횟수가 증가함에 따라서 CH_(4)의 CO_(2) reforming에 대한 선택도가 증가하영 일정한 수준에 도달하였다. Relationship between the redox property and the reactivity for CO₂ reforming of methane was investigated on 0.5wt% platinum-impregnated CeO₂, Ce_(0.5)Zr_(0.5)O₂ and ZrO₂ Whereas CO-O₂ and CO-CO₂ cyclic pulse experiments at 600℃ showed that the redox property was in the order of Pt/Ce_(0.5)Zr_(0.5)O₂>Pt/CeO₂>>Pt/ZrO₂, the reactivity for CO₂ reforming of methane was in the order Pt/ZrO₂>Pt/Ce_(0.5)Zr_(0.5)O₂>Pt/CeO₂ by pulse experiments at 550-600℃ with stoichiometric mixture of the reactants. From the fact that relatively irreducible Pt/ZrO₂ exhibited higher reactivity than Pt/Ce_(0.5)Zr_(0.5)O₂ possessing more vigorous redox property, it could be deduced that Pt/ZrO₂ follows the reaction mechanism unequal to that for Pt/Ce_(0.5)Zr_(0.5)O₂ or Pt/CeO₂. While the reactivity Pt/ZrO₂ reached a steady level from the beginning, the reactivity of Pt/Ce_(0.5)Zr_(0.5) and Pt/CeO₂ varied with the extent of catalyst reduction. Complete oxidation of methane was initially more dominant on Pt/Ce_(0.5)Zr_(0.5)O₂ due to its vigorous oxygen mobility, however, the selectivity toward CO₂ reforming of methane increased with the number of reactant pulses before it reached a steady level.

흰쥐 재생간의 알콜대사효소들의 활성치

문교철,곽춘식,정성광,김여희 啓明大學校 醫科大學 1988 계명의대학술지 Vol.7 No.2

A study was made on the change in the activities of the following during 10 post-operative days: alcohol dehydrogenase of regenerating rat livers after 70% (median and left lateral lobes) partial hepatectomy. After partial hepatectomy in the rats, activities of regenerating liver alcohol dehydrogenase significantly increased in the sixth day. The activities of microsomal ethanol-oxidizing system in the regenerating liver markedly increased from the third day after partial hepatectomy. However, no significant changes in hepatic catalase was noted throughout the experiments. The activities of cytosolic and microsomal aldehyde dehydrognease in the regenerating liver significantly increased from the sixthe day and the third to the sixth day respectively, but mitochondrial aldehyde dehydrogenase showed no change.

흰쥐 재생간의 Malate Dehydrogenase의 활성치

김여희,곽춘식,문교철 啓明大學校 醫科大學 1986 계명의대학술지 Vol.5 No.2

A study was made on the changes in the activities of the following during 6 post-perative days: Cytosolic and mitochondrial malate dehydrogenase of regenerating rat livers, and rat serum malate dehydrogenase after 70% (median and left lateral lobes) partial hepatectomy. The activities of lactate dehydrogenase and alanine aminotransferase in both serum and cytosol of regenerating rat liver were also measured. After parial hepatectomy in the rats, activity of serum malate dehydrogenase trmendously increased in in the span between the 12 hours and the second day. The activity of cytoslic malate dehydrogenase in the regenerating liver significantly increased from the first to the second day after partial hepatectomy. However, no significant changes in hepatic mitochondrial malate dehydrogenase was noted throughout the experiments. The activities of serum lactate dehydrogenase and alanine aminotransferase markedly elevated after partial hepatectomy. And activity of alanine aminotransferase significantly decreased in the hepatic cytosol after partial hepatectomy but hepatic cytosolic lactate dehydrogenase showed no change.

국내 주요 상수원수와 처리수에서 HAAs 생성 특성

염철민,최유식,변석종,조순행,윤제용 대한상하수도학회 2002 상하수도학회지 Vol.16 No.2

This study was conducted to investigate the haloacetic acid (HAAs) formation characteristics in raw and treated water in Korea. The raw and treated water from the five major rivers were examined to measure the HAAs concentrations and compared those with literature values. Major findings are as follows. First, average HAAs concentration of treated water (collected from three water treatment plants) in Korea appeared to be 62.5±66.7㎍/L (n=7) and this level is higher than the average trihalomethanes (THMs) concentration (13.2±12.9㎍/L, n=6933) reported recently. Second, the average formation potential of TCAA and DCAA after three days was found as 103±74㎍/L (n=14) and 76±36㎍/L (n=14), respectively. As this result was applied to US-EPA developed model equation for TCAA and DCAA formation, dissolved organic matter (DOM) in Korea has a tendency to produce more TCAA and DCAA as compared to US. This phenomenon was especially notable in DCAA. The sum of weight percentage of TCAA and DCAA which are individual component of HAAS was composed of 80% of HAAs.

알콜리즘에서 Buspirone에 대한 Cortisol과 Prolactin 반응

심주철,이정구,김정익,이유철,김영훈 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.2

연구목적: 본 연구는 buspirone에 대한 cortisol과 prolactin 반응을 통해 알콜리즘에서 5-HT1A 수용체기능을 조사하고자 하였다. 방법: 알콜리즘 환자군은 DSM-IV의 알콜리즘 진단기준에 부합되고 금주기간이 최소 3개월 이상이며 우울 및 불안증상이 없는, 한 정신병원 알콜 센터에 입원한 22명의 남자 환자였다. 대조군은 정상성인 남자 15명이었다. 이들에게 오전 9시에 5-HT□ 효현제인 buspirone 30mg을 경구 투여한 후 0, 30 , 60, 90, 120, 150분의 혈청 cortisol과 prolatine 농도를 측정한다. 결과: 환자군과 대조군간에 cortisol 기저치에는 유의한 차이가 없었다. Buspirone 투여 후 혈청 cortisol 농도는 정상대조군에서는 기저치에 비해 유의한 증가를 보였으나(p<0.01) 환자군에서는 유의환 증가가 없었다. 혈중 cortisol 농도는 buspiron 투여 60분 이후부터 환자군에서 정상 대조군에 비해 유의하게 저하되어 있었다(p<0.05). Buspirone에 대한 혈청 prolactin 반응은 환자군과 정상대조군간에 유의한 차이가 없었다. 결론: Buspirone 투여 후 둔마된 혈청 cortisol 반응을 통해 알콜리즘에 5-HT1A 수용체 반응성이 둔마되어 있음을 확인할 수 있었다. Objectives: The purpose of this study was to evaluate the prolactin and cortisol responses to 5-HT1A receptor activation by buspirone in alcoholics. Methods: The subjects were twenty two male alcoholic patients meeting the DSM-IV criteria for alcohol dependency and abstaining for more than 3 months. Patients were free from overt anxiety and depressive symptoms. Controls were fifteen male normal volunteers, with no psychiatric and medical illness. Blood samples for the measurement of serum cortisol and prolactin levels were drawn 0, 30, 60, 90, 120, 150 minutes after oral administration of 30mg buspirone hydrochloride at 9:00a.m. Results: The baseline cortisol levels were not significantly different between alcoholics and controls. Serum cortisol levels of controls after buspirone administration were significantly increased over time(p<0.01), but those of alcoholics did not increased. After 60 minutes following buspirone administration, cortisol levels were significantly lower in alcoholics than in contrlos(p<0.05). Prolactin responses to buspirone were not significantly different between the two groups. Conclusions: Our results suggested that 5-HT1A receptor function is decreased in alcoholic patients.

다공질 실리콘의 미세구조에 관한 연구

金英猷,洪思容,崔哲鍾 公州大學校 基礎科學硏究所 1994 自然科學硏究 Vol.3 No.-

단결정 실리론(p형)을 불화수소 속에서 양극 산화반응으로 다공질 실리콘을 제작하고 SEM과 AFM을 이용하여 그 미세구조를 조사하였다. 그리고 액체접촉에 의한 전기루미네선스(EL) 결과와 비교하여 논의 하였다. 이 결과 다공질 실리콘의 표면에는 0.1㎛정도의 미세입자가 형성되었으며, 이때 입자의 외형은 제작시간의 증가에 따라 다공도가 증가하여 입자로서의 형태가 뚜렷해졌으며 그 크기는 약간 작아졌다. 이 입자를 AFM으로 관찰한 결과 10nm정도의 미세한 실리콘 기둥과 이들 사이의 구멍으로 형성된 미세한 세선(細線)으로 형성되어 있었다. 한편 발광에 기여하는 구조는 미세입자라기 보다는 미세입자에 형성된 미세세선인 것으로 보여진다. 그리고 다공질 실리콘에서의 전기루미네선스의 최대 스펙트럼은 다공도에 영향을 받아 미세구조와 상당한 관계가 있는 것으로 나타났다. The porous silicon layers(PLS) were formed by electrochemical anodization of p-type Si wafers in 10%HF-ethanol solution. The micrometer to nanometer scale finestructures of porous silicon are investigated by using high resolution scanning electron microscope and atomic force microscope. The electroluminescence(EL) from PLS was investigated silicon/electrolyte interface in Na2SO4 aqueous solution. SEM and AFM observations revealed that the micrometer-scale structures of porous silicon are greatly depended on anodization time at costant current density. In contrast to these structures, nanometer-scale structures of porous silicon consisted of single crystalline silicon column and holes which have sizes of about tens nm. The EL spectrum changed by the porosity of finestructures.

흰쥐 재생간의 Leucine Aminopeptidase의 활성치

문교철,곽춘식,김여희 啓明大學校 醫科大學 1986 계명의대학술지 Vol.5 No.2

Changes in the activities of the followings have been studied over a period of 6 days after partial hepatectomy in rats: Plasma membrane, mitochondrial, nuclear and cytosolic leucine aminopeptidase and microsomal-particle bound aminopeptidase of the regenerating liver and serum leucine aminopeptidase. The activities of alkaliine phosphatase in the subcellular fractions were also measured. The activities of leucine aminopeptidase and alkaline phosphatase in serum markedly elevated from 12 hours to three days after partial hepatectomy in rats. The activity of plasma memberane-bound leucine aminopeptidase in the regenerating rat liver drastically increased during the first and the third days of the operation. And the activity of microsomal particle-bound aminopeptidase in the regenerating liver significantly increased between the second and the third days after operation. The activities of nuclear and cytosolic leucine aminopeptidase in the regenerating liver showed a substantial increase at the second day and from first to sixth day respectively after operation. However, no significant change in hepatic mitochondrial leucine aminopeptidase was noted throughout the experiments. The activities of plasma membrane, microsomal, mitochondrial, nuclear and cytosolic alkaline phosphatase in the regenerating liver markedly increased throughout the experiments.

Chlorpromazine으로 유발된 음경지속발기증 1례

신유호,윤도준,이충현,송지영,이상철 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.3

저자들은 항정신병약물 chlorpromazine 치료 중에 음경지속발기증이 발생하여 수술까지 시행하여 회복된 환자 1례를 체험하였기에 문헌고찰과 함께 보고하였다. 항우울제 trazodone과 함께 chlorpromazine, thioridazine과 같은 항정신병약물이 음경지속발기증의 원인과 관련이 있는 것으로 알려지고 있다. 이러한 약물에 의해 유발되는 음경지속발기증의 기전에 대해서는 알파-아드레날린 차단으로 인한다는 설이 많은 지지를 받고 있다. 치료는 보존적인 치료와 외과적인 치료가 있으며, 외과적인 치료로는 음경해면체 천자와 흡입 세척술 그리고 분로를 만들어 주는 방법들이 있다. 음경지속발기증은 신속한 진단과 치료를 하지 않을 경우 영구적인 발기불능을 초래할 수도 있는 부작용이므로 향정신약물 투여시 이에 대한 관심과 주의를 가져야 할 것이다. Antipsychotic drugs can induce several sexual side effects. Priapism, one of the side effects, is defined as "the persistent abnormal erection of the penis, which usually occurs without sexual desire". There has been an increasing number of reports recently linking the etiology of priapism with psychotropic medication. The drugs known to be associated with priapism are psychotropic drugs such as trazodone, chlorpromazine, thioridazine as well as antihypertensives, anticoagulants and so on. The mechanism of a drug which induces priapism is proposed to be mediated by its alpha-adrenergic blocking effect. Prompt diagnosis and treatment are essential. Priapism is a severe side effect, which can lead to impotence if prompt diagnosis and treatment are not carried out. There are medical and surgical treatments for priapism. The surgical treatments usually involve aspiration, irrigation and the creation of shunt. We report a case of priapism which developed after two years of chlorpromazine treatment. He is a 20-year-old man with schizophrenia. He experienced two times of brief episode of prolonged penile erection before developing intractable priapism. He was treated by shunt operation which showed satisfactory relief of priapism. It seemed by this case that duration and dosage of chlorpromazine were not closely related with priapism. Psychiatrist is needed to give attention to the priapism as one of sexual side effects due to antipsychotics though it is not common.

Effects of Intravenous Administration of Taurocholate on Hepatic Aryl Sulfotransferase Activity in Cholestatic Rats

곽춘식,--,-- 대한의생명과학회 2005 Biomedical Science Letters Vol.11 No.1

The possible mechanisms of increased aryl sulfotransferase (AST) isozymes activities in cholestatic rat liver were studied. Hepatic AST-Ⅰ, Ⅱ and -Ⅲ, Ⅳ activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial AST-Ⅰ, Ⅱ and -Ⅲ, Ⅳ, and microsomal AST-Ⅲ, Ⅳ as well as their Vmax values were found to be increased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. The results suggest that TCA stimulates biosynthesis of the AST in the liver.

식도 평활근종이 동반된 Alport 증후군 1례

정진영,김철민,임연정,김자형,유종우,최보화,홍수종,박영서 대한소아과학회 2002 小兒科 Vol.45 No.9