Ta₂O_(5) 게이트 pH-ISFET의 제조 및 그 동작특성

권대혁,김명규,이광만,손병기 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

To improve sensing characteristics of the pH-ISFET using LPCVD-grown Si_(3)N_(4), Ta_(2)O_(5) thin film depositied by RF reactive sputtering was used for hydrogen ion sensing gate and investigated sensing characteristics at various annealing temperatures. The XRD pattern showed that the crystal structure of the Ta20s thin film was amorphous when the annealing temperature was less than 500℃, δ-Ta_(2)O_(5) poly-crystal at MC Ta_(2)O_(5) gate pH-ISFET annealed at 400℃, O_(2) ambient for 1hour, the AES and RBS spectrum showed good stoichiometry (O/Ta=2.5). And its sensing characteristics showed good linearity and high sensitivity(57~59MV/pH) in the wide pH range(pH 2~12), and excellent long-term stability (0.03~0.05 pH/day). It can be concluded from these results that the sensing characteristics of Ta_(2)O_(5) gate pH-ISFET is more excellent than Si_(3)N_(4) gate pH-ISFET.

대장균에서 Thermus caldophilus GK24의 DNA Polymerase유전자의 고발현

권석태,김현규,김중수,이대실 성균관대학교 생명과학자원연구소 1997 生命資源科學硏究 Vol.4 No.2

Thermus caldophilus GK24 (Tca) DNA polymerase is highly useful enzyme for amplifying DNA fragments by polymerase chain reaction (PCR). A plasmid, pTCA, is expression vector for Tca DNA polymerase gene in Escherichia coli under the control of tac promoter and its expression level is low. For the high expression, the DNA sequence coding for NH_2-amino acid sequence of Tca DNA polymerase was changed by PCR, and then an expression vector pTCAM was constructed. The activity of Tca DNA polymerase in E. coli harboring for pTCAM has enhanced nearly 6-fold/ml than that for E. coli harboring pTCA.

생체적합성과 생분해성을 갖는 Polypeptide Copolymers의 합성과 물성에 관한 연구(Ⅲ): Polypeptide Hydrogels의 약물조절방출

강인규,권대룡,성용길 동국대학교 자연과학연구소 1991 자연과학연구 논문집 Vol.11 No.-

Poly(γ-benzyl L-glutamate) (PBLG)의 측쇄에 polyethylene glycol(PEG) 또는 ethanolamie(EA)을 반응시켜 적심성이 서로 다른 몇가지 폴리펩티드 공중합체를 합성하였고, 이들 공중함체의 약물방출특성을 살펴보았다. 합성된 폴리펩티드공중합체의 수분흡수율은 공중합체 중의 PEG 또는 EA 함량이 높아짐에 따라 증가하였다. PEG-PBLG-EA 공중합체로부터의 5-fluorouracil의 방출속도는 PEG-PBLG 공중합체로부터의 방출속도보다 크게 나타났으며, 이러한 결과는 팽윤성의 폴리펩티드를 합성하고자 할 때 사용되는 치환제로서는 PEG보다도 EA가 더욱 효과적이라는 것이 나타났다. 한편, PEG를 가교시킨 PBLG 공중합체막상에서는 5-fluorouracil의 방출에 기인하여 작은 pores를 명료하게 나타나고 있음을 알 수 있었다. Several copolypeptides having different swellabilities are are synthesized by introducing polyethylene glycol(PEG) or ethanolamine(EA) to the side chains of poly(γ-benzyl L-glutamate) (PBLG) and their drug release characteristics are examined. The degree of swelling of copolypeptide is increased by increasing PEG or EA content in the polymer. The release rate of 5-fluorouracil from the PEG-PBLG-EA copolymers was higher than that of the PEG-PBLG copolymers. This results indicated that EA is more effective than PEG for the preparation of the swellable polypeptides. It was observed, from the morphological study by scanning electron microscope, the pores are generated on the PEG-crosslinked PBLG, but not on the PEG-grafted-PBLG.

횡문근융해증과 급성 신부전 및 범발성 혈관내 응고장애를 동반한 열사병 1예

최대은,박수진,권오경,이한규,이영모,이상주,나기량,이강욱,신영태 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Heat stroke is a life-threatening illness characterized by an elevated core body temperature that rises above 40% and central nervous system dysfunctions that results in delirium, convulsions, or coma. Heat stroke is subdivided into two forms, classic and exertional. Since strenuous exercise is one of the major exacerbating and precipitating factors, the incidence of exertional heat stroke is high among young adult, especially military personnel undergoing military training. Exertional heat stroke commonly causes rhabdomyolysis, lactic acidosis, acute renal failure, shock and pulmonary edema. We report a case of heat stroke with rhabdomyolysis, acute renal failure, disseminated intravascular coagulopathy(DIC) after strenuous exercise. A 18 year old man was admitted to the hospital because of loss of consciousness. He was a wrestler and he had tried to lose 6kg in weight by jogging and strenuous exercise on that summer day with hot temperature. The development of this illness was favoured by much clothes inappropriate for that environmental condition with a purpose to enhance sweating, and by restricted intake of water and food. On admission, the blood pressure was 80/50mmHg, and body temperature was 39.4℃ with stuporous mentality. Laboratory finding were as follows : in complete blood cell count, hemoglobin was 16.7g/dL and platelet count was 158,000/ mm³. In blood chemistry, AST 1061U/L, ALT 201U/L, BUN 30mg/dL, Cr 2.2mg/dL, LDH 941IU/L, CK 696IU/L were resulted. In arterial blood gas analysis, pH 7.39, pCO₂ 30mmHg pO₂ 86mmHg, HCO₃ 18.4mEq/L, O₂ saturation 96.7% were resulted. In urinalysis, specific gravity 1.025, protein 3+, erythrocyte 2+ were resulted. In brain imaging study, brain CT finding was normal. After appropriate treatments with rapid cooling, hydration and supportive care, he improved with alert mental status. On 2nd hospital day, in laboratory result, thrombocytopenia and coagulopathy were appeared and renal insufficiency was aggravated. So he was treated with platelet concentrate and fresh frosen plasma for DIC, and enough hydration for appropriate urine volume preservation. After all, On 22nd hospital day, he fully recovered and discharged. Nowadays, with followed for some duration, he is wellbeing with no complications.

전국 단위 감시체계의 현황과 전망

강성규,안연순,지영구,김형옥,하미나,권호장,백남종,김성아,홍윤철,김재용,강대희,정혜선,하은희 대한산업의학회 2001 대한직업환경의학회지 Vol.13 No.2

가열면상 단일액적의 핵비등 열전달에 표면거칠기가 미치는 영향

최인규,남궁규완,고대권 연세대학교 대학원 1985 延世論叢 Vol.21 No.4

An experimental study was carried out to investigate the effects of surface roughness in nucleate boiling heat transfer of a liquid droplet on heated stainless steel plate of three different roughness combined with three kinds of droplets, namely distilled water, ethanol and n-heptane. Major points of interests were to make clear the effects of roughness on the evaporation time temperature variation of the plate surface during evaporation and timeaveraged heat flux. Conclusively the results of the study are summarized in the following equational form 그림삽입(원문참조) (q￣ is time-averaged heat flux, 그림삽입(원문참조) is time-averaged surface temperature minus saturation temperature) The effects of roughness 그림삽입(원문참조) is found to make the values of m and C larger (refer Table. 3) and to make q￣ larger.

허혈성 심질환에서 염증지표에 관한 연구

번정득,권영주,박상호,한대희,이상철,강진환,김명구,심규혁,최병조,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background : Atherosclerosis is the chief underlying cause of ischemic heart disease and there is increasing evidence that inflammation is an important determinant of the development of atherosclerosis. We assessed the levels of inflammatory markers in patients with ischemic heart disease and normal group who has normal coronary angiograms. Materials and Methods : Coronary angiography was performed in 142 patients. 107 patients of ischemic heart disease(stable angina pectoris 58, unstable angina pectoris 30, Acute myocardial infarction 19) and 38 normal control subjects. We assessed the level of inflammatory markers, such as CRP, ESR, fibrinogen and leukocyte. Results : CRP, ESR and fibrinogen values of the patients with stable angina pectoris and unstable angina pectoris were higher than that of normal control group, but there were no statistical significance. Leukocyte value of the patients with unstable angina pectoris(9003.3±701.5/mm^(3)) was significantly higher than that of the patients with stable angina pectoris(6685.5±245.8/mm^(3)) and normal control subjects(6394.3±235.1/mm^(3)). CRP, ESR and fibrinogen values of the patients with acute myocardial infarction were also higher than that of normal control subjects. CRP was 3.88±2.05 mg/dL in acute mocardial infarction group, and 0.29±0.15 mg/dL in normal control subject group(p<0.05). Fibrinogen was 541.6±45.1 mg/dL in acute myocardial infarction group, 321.4±25.6 mg/dL in normal control subject group(p<0.05). Leukocyte was 10942.1±737.6/mm^(3) in acute myocardial infarction group, 6394.3±235.1/mm^(3) in normal control subject group(p<0.05). Conclusions : This study demonstrate that CRP, fibrinogen and leukocyte values of acute myocardial infarction group were significantly higher than that of control group and stable, unstable argina pectoris group. Leucokyte values were significantly elevated in unstable angina group, but CRP values were not in unstable angina group.

산처리에 의한 정수슬러지 감량화

이병문,권재현,안규홍,이석헌,권대영 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

The acidic treatment of waterworks sludge released organic materials as well as inorganics such as Al, Fe and Mn. Through solubilization as mentioned above, the content of suspended solids reduced by 18% at final pH 3.5. It also increased thickening efficiency and dewaterability of sludge. However overdosing of H_2SO_4 made dewaterability deteriorated. It showed that the optimal condition of acidic treatment be as follows; 5.5㎖ dose of H_2SO_4(97%)/1 sludge, final pH 3.5 and 15minutes of reaction time. Under these conditions, reduction efficiencies of sludge through thickening and dewatering were 57% and 92.2% respectively and then 7.8% of raw sludge released as cake compared to 10.5% without acidic pre-treatment. Therefore, mass of dewatered cake decreased by 26% through acidic treatment. Water content of dewatered cake was reduced from 71% to 62% due to this treatment. The changes of sludge properties including particle size, zeta-potential and bound water by acidic treatment appear to be important keys in assesment of the improvement of sludge dewaterability.

관상동맥질환 환자에서 스텐트 시술 후 재협착에 관한 연구

강진환,권영주,박상호,한대희,이상철,김명구,변정득,최병조,심규혁,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background and aims : In the coronary artery disease, a rate of restenosis was much decreased by placement of coronary stent than when percutaneous transluminal coronary angioplasty has been applied, but there are still important clinical problems of restenosis. There has been many progressive studies about various factors contributed to this restenosis. So, we studied a relation between restenosis after placement of coronary stent in the coronary artery disease and many clinical factors, characteristics of stenotic lesion and procedural factors, and also assessed the restenosis rate of various coronary stents. Methods : Total 58 lesions(46 cases of patients ; man 30, woman 16) were evaluated, which has been performed a follow-up coronary angiography after 6 months (mean 188 days) since coronary stent had been placed. Various stents were implanted and assessed a relation between restenosis and many factors. Results : Of 58 lesions were target stenotic studies, there were 22 of restenotic lesions(37.9%), and the restenosis rate wes statistically significant difference in the relation with diabetes mellitus(p<0.05), group of acute myocardial infarction(p<0.05) among clinical diagnosis of ischemic heart disease(stable angina, unstable angina and acute myocardial infarction) in clinical factors and with high dilation pressure of stent(p<0.05) in procedural factors. When the rate of restenosis was evaluated among implanted stents, it was lowest in the Multilink^(®) stent and highest in the Nir Royal^(®) stent(60%). Conclusion : In this study of restenosis and various factors after placement of stents in the coronary artety disease, factors such as diabetes mellitus, group of acute myocardial infarction and a dilation pressure of stent were significant related with restenosis and the restenosis rate of Multilink^(®) stent was lowest and the highest restenosis rate was of Nir Royal^(®) stent.

멀티미디어 연속매체 데이터를 위한 동적 그룹화 버퍼 재배치 알고리즘

장은정,최항규,권대희 강원대학교 정보통신연구소 1998 정보통신논문지 Vol.2 No.-

Due to the characteristics of multimedia data and interactive usage, multimedia applications demand specific support from the conventional database management systems. Existing buffer management strategies, such as LRU(Least Recently Used) and MRU(Most Recently Used), do not sufficiently support the handling of continuous media data in realtime multimedia application, such as VOD(Viedo On Demand) services. They exploit neither the knowledge of outstanding requests nor the fact that continuous media data is accessed sequentially. In this paper, we propose a new buffer management strategy for continuous media storage servers, which takes into account the characteristics of continuous media data. Our buffer management strategy effectively handles the buffer frames by grouping the user transactions with the closely related request intervals. In the performance study, we conduct a simulation experiment and then show that out algorithm outperforms other buffer management strategies.