적외선 흡수 분광법 및 DPC를 이용한 치과용 수복재의 광중합 거동 분석

정찬문,김중곤,최준호,장두옥,김경남,김광만 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.1

Mechanical properties of compomers would be obtained mainly by photopolymerization by visible light irradiation. Photopolymerization behavior of two commercial compomers was investigated by FT-IR spectral analysis and differential photocalorimetry(DPC). The results obtained were as follows: 1. From FT-IR analysis, it was found that the compomer products were photocured mainly by radical polymerizations of multifunctional methacrylate monomers. Final conversion values of the polymerizations after exposure to visible light for 60 sec were 67% for Dyract and 59% for Compoglass. 2. Upon exposure the compomers exhibited autoacceleration and autodeceleration, which are usually observed in bulk polymerizations of multifunctional monomers. 3. Dyract showed higher rate of polymerization and conversion of double bond than Compoglass.

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

AGV 용 서스펜션의 진동 모드에 관한연구 : 중력 가속도가 5G인 경우 A Case of Gravity Acceleration is 5G

주만식,김민주,이승수,최영철,추정근,김중완,전언찬 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

This study is to choose the most proper model for AGV throughout simulation of behavior of suspension to reduce trial and error because there is no AGV treating heavy weight at harbor loading and unloading at home. Therefore, we estimate the vibration modes of the various suspension applied to AGV, which is over 75 ton included the weight of two containers on 5G using the Matlab, one of the simulation programs

중력가속도의 변화에 따른 자동운반차량용 서스펜션의 진동모드에 관한 연구

주만식,김민주,이승수,최영철,추정근,김중완,전언찬 동아대학교 해양자원연구소 2000 硏究論文集 Vol.13 No.1

This study is to choose the most proper model for AGV Throughout simulation of behavior of suspension to reduce trial and error because there is no AGV treating heavy weight at harbor loading and unloading at home. Therefore, we estimate the vibration modes of the various suspensions applied to AGV, which is over 75 ton included the weight of two containers using the Matlab in the case of G and 5G, one of the simulation programs.

Theoretial Studies of Resonance Raman Spectrum of Porphyrin

Choi, Chan-You,Choi, Joong-Gill 동국대학교 1987 論文集 Vol.26 No.-

Resonance Raman 분광법은 hemoprotein에서 보결분자단의 구조관측을 위한 높은 감도와 선택성을 지닌 테크닉이다. 이 분광법으로 얻은 실험결과는 heme의 구조와 metalloporphyrin에서의 여기전자 상태에 대한 새로운 정보를 제공해 준다. "Picket Fence Porphyrin"은 산소분자가 결합되어 있는 hemoprtein에 있어서 대단히 중요한 모델 화합물로 알려져 있다. 본 논문에서는 ring dye laser의 범위안에서 resonace Raman 분광법을 이용하여 이 화합물에 있어서 산소 분자결합에 관계되는 스텍트럼의 변화에 대하여 연구하였다. 이론에서 기대했던 바와 같이 대부분의 Raman modes에서의 여기상태 모양은 O-O(α)Q band에서 최대가 됨이 밝혀졌다. 또한 편극된(polarized) 것과 변칙적으로 편극된 진동들의 편극소거비(depolarization ratio)는 symmetry의 변형으로써 설명될 수 있는 dispersion을 나타내었다. 그러나 산소분자의 결합에 있어서 Fe-O_2 의 stretching vibration은 확인되지 않았으며 산화상태나 스핀상태를 나타내는 어떠한 주파수의 이동도 관찰되지 않았다. 일반적으로 산화상태에서 산화과정의 변화를 직접 예측할 수는 없는 반면, 스핀상태는 높은 스핀에서 낮은 스핀으로 변화하는 것을 기대할 수 있다. 이러한 스핀상태 marker는 전혀 예측하지 못했던 결과이나 만일 짧은 파장을 사용하여 β-band에 더욱 근접한 exciting광선을 이용하면 스핀상태 marker 주파수의 변화는 관찰되리라 예상된다.

Haemocytes responses of the pearl oyster, Pincdata fucata, at different temperatures

Choi, Young-Joon,Hwang, Jee-Youn,Baeck, Gun-Wook,Kim, Mu-Chan,Park, Hyung-Jun,Choi, Byoung-Dae,Kang, Suk-Joong,Park, Chan-Il The Korean Society of Fish Pathology 2008 한국어병학회지 Vol.21 No.3

The effects of temperatures on pearl oyster, Pincdata fucata were studied by evaluating some functional immune responses of the haemocytes. Water temperature is one of the most important factors in bivalve immune defense. Haemocytes comprise a primary line by inflammation, encapsulation and phagocytosis. These phagocytic abilities of haemocytes were observed in different temperatures. The number of the circulating haemocytes by migratory assay, phagocytic activities by MTT assay and reactive oxygen species production of haemocytes by CL assay were measured at different temperatures. Results showed that pearl oyster maintained at 20℃ and 25℃ displayed significantly higher values for all the measured immune parameters in comparison to maintained at 10, 15, and 30℃.

Management of giant hepatic cysts in the laparoscopic era

Chan Joong Choi,Young Hoon Kim,Young Hoon Roh,Ghap Joong Jung,Jeong Wook Seo,Yang Hyun Baek,Sung Wook Lee,Myung Hwan Roh,San Young Han,Jin Sook Jeong 대한외과학회 2013 Annals of Surgical Treatment and Research(ASRT) Vol.85 No.3

Purpose: We sought to evaluate the feasibility and outcomes of laparoscopic resection of giant hepatic cysts and surgical success, focusing on cyst recurrence. Methods: From February 2004 to August 2011, 37 consecutive patients with symptomatic hepatic cysts were evaluated and treated at Dong-A University Hospital. Indications were simple cysts (n = 20), multiple cysts (n = 6), polycystic disease (n = 2), and cystadenoma (n = 9). Results: The median patient age was 64 years, with a mean lesion diameter of 11.4 cm. The coincidence between preoperative imaging and final pathologic diagnosis was 54% and half (n = 19) of the cysts were located in segments VII and VIII. Twenty-two patients had American Society of Anesthesiologists (ASA) classification I and II, and nine had ASA classification III. Surgical treatment of hepatic cysts were open liver resection (n = 3), laparoscopic deroofing (n = 24), laparoscopic cyst excision (n = 4), laparoscopic left lateral sectionectomy (n = 2), hand assisted laparoscopic procedure (n = 2), and single port laparoscopic deroofing (n = 2). The mean fellow-up was 21 months, and six patients (16%) experienced radiographicapparent recurrence. Reoperation due to recurrence was performed in two patients. Among the factors predicting recurrence, multivariate analysis revealed that interventional radiological procedures and pathologic diagnosis were statistically significant. Conclusion: Laparoscopic resection of giant hepatic cysts is a simple and effective method to relieve symptoms with minimal surgical trauma. Moreover, the recurrence is dependent on the type of pathology involved, and the sclerotherapy undertaken.

Management of Giant Hepatic Cysts in the Laparoscopic Era

Chan Joong Choi,Young Hoon Kim,Young Hoon Roh,Ghap Joong Jung,Jeong Wook Seo,Yang Hyun Baek,Sung Wook Lee,Myung Hwan Roh,San Young Han,Jin Sook Jeong 한국간담췌외과학회 2013 한국간담췌외과학회 학술대회지 Vol.2013 No.4

성인의 서혜부 탈장에 있어서 매쉬를 이용한 세 가지 탈장 교정술의 비교

최찬중(Chan Joong Choi),박기재(Ki Jae Park),김성흔(Sung Heun Kim) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.76 No.2

Purpose: The aim of this study was to compare three types of hernioplasty using a mesh: Lichtenstein, Mesh-plug and Prolene Hernia System. Methods: From February 2002 to April 2007, we retrospectively studied the clinical outcome of 138 cases of adult inguinal hernia patients who had operations performed with the use of mesh. Three types of mesh operations were composed of Lichtenstein repair group (LR group; N=18), Mesh plug repair group (MR group; N=38) and Prolene hernia system group (PHS group; N=82). The Clinical features and outcomes of the three groups were compared by age, sex, operation time, lengths of hospital stay, numbers of post-operative intravenous analgesics, complications, and recurrence. Results: Mean age of three groups was 50.2±20.7, 51.0±18.4 and 61.5±15.9 years for LR. MR, PHS groups, respectively. The PHS group was significantly older than other two groups (P=0.002). The sex, operation time and lengths of hospital stay were not significantly different among the three groups. Numbers of intravenous analgesics used after the operations were 1.7±1.2, 2.7±2.2, 3.3±2.0 in the LR, MR, PHS groups, respectively. A lesser amount of IV analgesics was injected into the LR group than the PHS group. Although some complications occurred such as wound infection, hematoma, dehiscence, testicular edema in the three groups, there were no significant differences among the three groups. There were no recurrences in all three groups. Conclusion: We could not find any better outcome among the LR, MR and PHS groups.

Haemocytes responses of the pearl oyster, Pincdata fucata, at different temperatures

( Young Joon Choi ),( Jee Youn Hwang ),( Gun Wook Baeck ),( Mu Chan Kim ),( Hyun Jun Park ),( Byoung Dae Choi ),( Suk Joong Kang ),( Chan Il Park ) 한국어병학회 2008 한국어병학회지 Vol.21 No.3