최근 10년간 원광의대병원에서 시행한 소아 심장혈관 수술의 임상적 고찰

윤향석,정수미,최두영,오광수,오연균,김종덕,양현웅,이삼윤,김형곤,최종범,최순호,노병석 圓光大學校 醫科學硏究所 1995 圓光醫科學 Vol.11 No.2

We reviewed 10 years experiences of the clinical aspects and early postoperative results in 544 pediatric patients(age less than 16 years old). Among them. 529 cases had the congenital heart diseases, and 15 had the acquired diseases. Open heart surgery was performed in 413 patients. 115 cases were treated with non-open heart surgery. 16 with interventional catheterization. Annual increase of the cardiac patients was not significant in recent 10 years, except slight increase in 1994. The mean age of the study patients had been evidently changed to younger year by year. Total mortality rate of the open heart surgery was 6.4%. The cyanotic congenital heart diseases were high in early postoperative mortality by 25.7%, whereas 4% in acyanotic group. The age group less than one month was most highest in surgical mortality(66.7%). There were no deaths in patients with patent ductus arteriosus(103 cases), atrial septal defect(83 cases) or pulmonary stenosis(17 cases). Among 220 patients with ventricular septal defects(VSD). 10(4.5%) were died early postoperatively. In cyanotic group, the patients with pulmonary atresia with ventricular septal defects(PAVSD), transposition of the great arteries(TGA), interrupted aortic arch(IAA), complex cardiac anomalies with isomerism seemed to be most susceptible to an early death.

Combustion characteristics of gaseous inverse O₂/H₂ coaxial jet flames in a single-element model combustor

Kim, Tae Young,Choi, Sun,Kim, Young Hoo,Ahn, Yeong Jong,Kim, Hee Kyung,Kwon, Oh Chae Elsevier 2018 ENERGY Vol.155 No.-

<P><B>Abstract</B></P> <P>To effectively design hydrogen (H<SUB>2</SUB>)/oxygen (O<SUB>2</SUB>) liquid rocket engines through understanding the combustion characteristics of H<SUB>2</SUB>/O<SUB>2</SUB> bipropellants, fundamental studies for the bipropellants in different phases are needed. This study is focused on the combustion characteristics of inverse gaseous O<SUB>2</SUB>/H<SUB>2</SUB> coaxial jet flames in a single-element model combustor as a preliminary step for succeeding studies of injection at different phases in the combustor, visualizing flame structure by direct imaging, OH<SUP>∗</SUP> chemiluminescence and OH planar laser-induced fluorescence. With increasing Reynolds number (Re), the frequency of occurrence of the local flame extinction increases and the length of the disconnected OH reaction zone is extended. The OH layer thickness increases downstream, while it is almost constant where the local flame extinction occurs and decreases with increasing Re due to the enhanced strain and scalar-dissipation rates. The excessive flame wrinkledness increases the local flame strain rate and results in the local flame extinction, exhibiting the tendency of increasing and then decreasing flame surface density with increasing Re. The probability density function of OH intensity quantifies the fluctuation intensity of OH radicals and the possibility of the local flame extinction. A useful database is provided for modeling the combustion of H<SUB>2</SUB>/O<SUB>2</SUB> bipropellants under different phases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A useful database for modeling the H<SUB>2</SUB>/O<SUB>2</SUB> bipropellant combustion is provided. </LI> <LI> Local flame extinction frequently occurs at high Reynolds number (<I>Re</I>). </LI> <LI> OH probability density function indicates the possibility of local extinction. </LI> <LI> Flame surface density increases and then decreases with increasing <I>Re</I>. </LI> <LI> Strong burning of O<SUB>2</SUB>/H<SUB>2</SUB> causes laminar-like combustion near the injector lip. </LI> </UL> </P>

Chlorhexidine 처리가 상아질 접착제의 미세인장결합강도에 미치는 영향

오은화,최경규,김종률,박상진 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

본 연구는 상아질 혼성층의 교원섬유를 가수분해하는 효소인 MMPs (Matrix metalloproteinses) 억제제로 알려진 chlorhexidine (CHX)을 적용 후 결합강도를 측정하였으며, 이를 각각 열순환 처리 후 결합강도를 측정하였다. 또한 주사전자현미경으로 접착계면메서의 파괴 양상을 비교 분석하였다. 우식이 없는 발거한 32 개의 제 3 대구치의 교합면 상아질을 노출시키고 GI그룹에서는 dentin conditioner를 처리 후 2% chlorhexidine을 적용시키고, 산부식 접착제 그룹에서는 인산 산부식을 시행하고 2 % chlorhexidine을 적용 후 3단계 산부식형 상아질 접착제 (Scotchbond Multipurpose, SM), 2단계 산부식형 상아질 접착제 (Single Bond, SB)를 도포하고, 자가부식 접착제 그룹에서는 2 % chlorhexidine 적용 후 자가부식 상아질 접착제 (Clearfil Tri-S, TS)를 도포한다. 이후 복합 레진 (Z-250)과 GI (Fuji-II LC)를 충전한 시편을 1 ㎟의 단면을 갖는 beam으로 제작하여 열순환 하지 않거나, 10,000 회 열순환 (5 ~ 55 ℃)하였다. Universal testing machine (EZ-test: Shimadzu, Japan)에서 cross head speed 1 mm/min로 인장력을 가하여 , 미세인장결합강도를 측정하였다. 실험 결과는 유의수준 0.05 1evel에서 two-way ANOVA를 이용하여 통계분석하였다. 그 후 파절된 시편의 파괴 양상을 현미경 (SEM)으로 관찰하여 다음과 같은 갈론을 얻었다; 1. 2 % CHX을 적용한 모든 실험군에서 상아질과의 미세인장결합강도가 증가하였고, 열순환은 상아질과의 미세인장 결합강도를 감소시켰다 (P>0.05). 2. CHX 적용 후 열순환 한 군은 CHX을 적용하지 않고 열순환한 군에 비하여, 상아질과의 미세인장결합강도가 높았으며 , 특히 GI와 TS군에서 유의한 차이를 나타내었다 (P<0.05). 3. 파괴 양상 분석 결과, 혼성층에서의 접착성 파괴를 보이며, CHX을 적용하면 혼성층 기저부에서 상부로 파괴 부위가 옮겨가는 양상을 나타내었다. 이상의 연구 결과를 토대로, MMPs 억제제인 2 % CHX은 글래스 아이오노머 시멘트와 상아질 접착제의 초기 미세인장결합강도에는 영향을 미치지 않으며 ,CHX 적용이 접착 내구성을 유지하는데 도움이 되었다. The purpose of this study was to evaluate the effect of chlorhexidine (CHX) on microtensile bond strength (μTBS) of dentin bonding systems. Dentin collagenolytic and gelatinolytic activities can be suppressed by protease inhibitors. indicating that MMPs (Matrix metalloproteinases) inhibition could be beneficial in the preservation of hybrid layers. Chlorhexidine (CHX) is known as an inhibitor of MMPs activity in vitro. The experiment was proceeded as follows : At first, flat occlusal surfaces were prepared on mid-coronal dentin of extracted third molars. GI(Glass lonomer) group was treated with dentin conditioner, and then, applied with 2 % CHX. Both SM (Scotchbond Multipurpose) and SB (Single Bond) group were applied with CHX after acid-etched with 37% phosphoric acid. TS (Clearfil Tri-S) group was applied with CHX, and then, with adhesives. Hybrid composite Z-250 and resin-modified glass ionomer Fuji-II LC was built up on experimental dentin surfaces. Half of them were subjected to 10,000 thermocycle, while the others were tested immediately. With the resulting data, statistically two-way ANOVA was performed to assess the μTBS before and after thermocycling and the effect of CHX. All statistical tests were carried out at the 95 % level of confidence. The failure mode of the testing samples was observed under a scanning electron microscopy (SEM). Within limited results, the results of this study were as follows; 1. In all experimental groups applied with 2 % chlorhexidine, the microtensile bond strength increased, and thermocycling decreased the microtensile bond strength (P > 0.05). 2. Compared to the thermocycling groups without chlorhexidine, those with both thermocycling and chlorhexidine showed higher microtensile bond strength, and there was significant difference especially in GI and TS groups.

토양미생물을 이용한 하수의 질소제거효율 향상

최영균,오동익,이종영,손대희 대구대학교 환경기술연구소 2005 미래환경기술 Vol.1 No.2

The effect of humus soil on biological denitrification was investigated through NUR batch tests. Specific denitrification rate of HMLE(Modified Ludzack Ettinger process combined with Humus soil contactor) and CMLE(Control Modified Ludzack Ettinger process) sludges as well as COD consumed for denitrification could be estimated from the batch tests. Two linear phases of denitrification rate could be observed when acetate was used as a carbon source. However, denitrification behavior was composed of three linear phases when a primary settled municipal wastewater(PW) was used as a carbon source. The specific denitrification rates on SBCOD(slowly biodegradable COD) fraction in raw wastewater were estimated 4.82 and 3.73 mg N/g VSS·hr when HMLE and CMLE sludge was used as a seed sludge. It means that the hydrolysis rate of HMLE sludge on SBCOD fraction was higher than that of CMLE sludge. Actinomycetes, one of the soil microorganisms, was estimated 150,000 actinomycetes/ml in the biomass of HMLE process, which was 10 times higher than that of CMLE process. Actinomycetes was well known for its distinguished hydrolyzing ability on particulate organic matter. Almost of input COD was utilized for denitrification and cell synthesis when HMLE sludge was used as a seed sludge in NUR batch test. While, about 70% of input COD was comsumed when CBNR sludge was used. It means that substrate utilization rate, especially SBCOD utilization rate, of HMLE sludge was higher than that of CMLE sludge.

장군봉(봉화군) 일대의 식물상

한종원, 양선규, 최슬기, 장창석, 김규식, 오병운 忠北大學校部設基礎科學硏究所 2007 自然科學硏究 Vol.21 No.-

-본문참고-

만성 재발성 소아 흉통의 원인 질환과 임상양상

최은정,이은아,이창우,최두영,오연균,김종덕,윤향석 대한소아과학회 2004 小兒科 Vol.47 No.6

금강유역 수질오염 실태조사

최신석,오희목,강명규,조통래,이규승,유종국,이영하 忠南大學校 環境問題硏究所 1988 環境硏究 Vol.6 No.1

조사 구역 상류 지점의 평균 수질은 pH가 7.1, DO가 8.3mg/ℓ, BOD가 1.7mg/ℓ, COD가 1.7mg/ℓ, SS가 15.4mg/ℓ, 분변성 대장균이 1.1x10³ MPN/100ml고 상수원 수 1급 내지 2급의 양호한 상태이고 하류지점의 수질은 pH가 6.8, DO가 7.7mg/ℓ, BOD가 2.2mg/ℓ, COD가 2.4mg/ℓ, 분변성 대장균이 1.7x10³MPN/100ml로 상수원 수 2급 내지 3급의 상태를 나타내 하류로 내려가면서 오염도가 증가하는 것으로 나타났다. 청주시의 영향을 크게 받는 미호천 하류의 평균수질은 pH가 7.2, DO가 6.3mg/ℓ, BOD가 16.2mg/ℓ, COD가 15.1mg/ℓ, 분변성 대장균이 1.6x10??MPN/100ml로 심각한 오염 상태를 보여 청주시와 대전시가 금강 본류의 주 수질 오염원으로 나타났다. 영양 염류 (NH₃-N, NO₂-N, NO₃-N, PO₄-P)와 무기성 유해 성분 (Cl-, CN-, F-)의 함량은 지천의 일부 지점을 제외하고는 극히 낮은 수준으로 검출되었으며, 유기인, 페놀류, PCB 성분은 조사기간 중 전혀 검출되지 않았다. 또한 Fe, Zn, Cu, Mn, Cr, Pb, Cd, Hg등의 중금속은 검출되지 않거나 하천 수질 기준 또는 식용수 수질 기준의 허용치를 초과하지 않는 양호한 수준으로 나타났다.

백두대간(추풍령-덕유산)구간의 식물상

한종원, 양선규, 최슬기, 장창석, 오병운 忠北大學校部設基礎科學硏究所 2007 自然科學硏究 Vol.21 No.-

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골다공증 위험군의 조기발견을 위한 골교체율 지표의 유용성

최종태,오석,한기옥,한인권 대한골대사학회 1996 대한골대사학회지 Vol.3 No.1

정량적 전산화 단층 촬영(pQCT)을 이용한 여성 및 남성의 골밀도 변화

오석,최종태,한인권 대한골대사학회 1996 대한골대사학회지 Vol.3 No.1