Space holder 방법으로 제조된 다공질 타이타늄의 기계적 성질에 대한 Computed-Tomography를 이용한 유한요소해석

이동준,안동현,이병갑,정지원,오상호,이종수,김형섭,Lee, Dong Jun,Ahn, Dong-Hyun,Lee, Byounggab,Jeong, Jiwon,Oh, Sang Ho,Lee, Chong Soo,Kim, Hyoung Seop 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.5

In this study, porous titanium samples were manufactured by space holder methods using two kinds of urea and sodium chloride space holders. Three-dimensional pore structures were obtained by a computed-tomography (CT) technique and utilized for finite element analysis in order to investigate the mechanical properties. The CT-based finite element analyses were in better agreement with the experimental results than unit cell model-based analyses. Both the experimental and CT-based results showed the same tendency that the elastic modulus decreased with increasing the porosities. The total porosity of the bulk body plays a key role in determining the elastic modulus of porous materials.

방사선수술을 위한 노발리스 품질관리 프로토콜 개발

이동준,이경남,이석,이상훈,김대홍,Lee, Dong-Joon,Lee, Kyung-Nam,Lee, Suk,Lee, Sang-Hoon,Kim, Dae-Hong 한국의학물리학회 2010 의학물리 Vol.21 No.1

국내에서 방사선치료를 위한 선형가속기 품질관리 프로토콜은 많이 개발되어 왔지만 선형가속기를 기반으로 하는 방사선수술장비의 품질관리 프로토콜 개발은 현재까지 거의 이루어져 있지 않고 있다. 이에 본 연구는 선형가속기 기반 일체형 방사선수술장비인 노발리스의 정확도 및 정밀도를 유지하기 위하여 일간, 주간, 월간, 연간에 주기적으로 시행하여야 하는 노발리스 품질관리 프로토콜을 개발 하고 품질관리 상태의 종합적 확인을 할 수 있는 해부학적 팬텀을 제작하였다. 이를 위하여 국내외의 선형가속기를 이용하는 방사선수술 품질관리 프로토콜의 수집 및 분석을 통해 필수적인 품질관리항목과 각 항목의 허용치를 정하였다. 노발리스 품질관리 항목은 기계적 정확도 부분과 방사선 전달 부분의 2가지로 분리하고 기계적 정확도 부분은 방사선발생 장치부, 보조장치부, 그리고 미세다엽 시준기부의 3가지 부분으로 방사선 전달부분은 치료 중심점 평가와 선량학적 평가의 2가지 부분으로 나누어 작성하였다. 최종적으로 노발리스 품질관리 유지를 위하여 시행하여야 하는 일간, 주간, 월간, 연간의 노발리스 품질관리 항목 표를 완성하였다. 완성된 노발리스 품질관리항목 표는 노발리스가 방사선수술에 적합한 정확도 및 정밀도를 유지하는데 필요한 지표로서 기여 할 수 있을 것이라 생각된다. In Republic of Korea, there are many Quality Assurance protocol for general radiation treatment machine such as linac. However, Quality Assurance protocol for radiosurgery treatment system is not ready perfectly. One of the radiation treatment machine for radiosurgery, novalis system needs to suitable Quality Assurance protocol for using it right way during radiation treatment and maintaining suitable accuracy for daily, weekly, monthly and annually periods. Therefore, in this article, we develop Quality Assurance protocol for novalis system. We collected and analysed domestic and foreign novalis Quality Assurance protocol. After that, we selected essential QA items and each tolerance range for developing proper QA protocol, and we made anatomical phantom for execution of selected QA items and evaluation of overall state of QA, and then, we use this measured value as a reference. Quality Assurance items are consisted of Mechanical accuracy QA part and Radiation delivery QA part. Mechanical accuracy QA part is comprised of radiation generation machine part, assistive devices part and multi-leaf collimator part. Radiation delivery QA part is divided into radiation isocenter accuracy and dosimetric evaluation. After that, developed novalis QA tables are made by using these QA items. These novalis QA tables would be used to good standard in order to maintain apt accuracy for radiosurgery in daily, weekly, monthly and annually periods.

고압비틀림 공정을 이용한 구리 분말의 치밀화

이동준,윤은유,강수영,이정환,김형섭,Lee, Dong-Jun,Yoon, Eun-Yoo,Kang, Soo-Young,Lee, Jung-Hwan,Kim, Hyoung-Seop 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.5

In this study, electrolytic copper powders were consolidated by high-pressure torsion process (HPT) which is the most effective process to produce bulk ultrafine grained and nanocrystalline metallic materials among various severe plastic deformation processes. The bulk samples were manufactured by the HPT process at 2.5 GPa and 1/2, 1 and 10 turns. After 10 turns, full densification was achieved by high pressure with shear deformation and ultrafine grained structure (average grain size of 677 nm) was observed by electron backscatter diffraction and a scanning transmission electron microscope.

분말 표면 조도의 3차원 레이저 분석기를 이용한 정량화와 압분성형체 강도에 미치는 영향 분석

이동준,윤은유,김하늘,강희수,이언식,김형섭,Lee, Dong-Jun,Yoon, Eun-Yoo,Kim, Ha-Neul,Kang, Hee-Soo,Lee, Eon-Sik,Kim, Hyoung-Seop 한국분말야금학회 2011 한국분말재료학회지 (KPMI) Vol.18 No.5

Green strength is an important property of powders since high green strength guarantees easy and safe handling before sintering. The green strength of a powder compact is related to mainly mechanical and surface characters, governed by interlocking of the particles. In this study, the effect of powder surface roughness on the green strength of iron powders was investigated using a transverse rupture test. Three-dimensional laser profiler was employed for quantitative analyses of the surface roughness. Two different surface conditions, i.e. surface roughness, of powders were compared. The powders having rough surfaces show higher green strength than the round surface powders since higher roughness leads increasing interlocked area between the contacting powders.

만성 심낭염의 외과적 요법

이동준,최순호,Lee, Dong-Jun,Choe, Sun-Ho 대한흉부심장혈관외과학회 1978 Journal of Chest Surgery (J Chest Surg) Vol.11 No.3

19 chronic pericarditis patients reviewed who were treated by surgical intervention in the Department of Thoracic and Cardiovascular Surgery, Chonnam University Hospital during the recent 10 years from January of 1968 to January of 1978. 2. There were 14males and 5 females in this series. Range of age varied from 110 days to 61 years. 2. There were two hospital death, one expired 2 days and another 3 days after the pericardiectomy. In both of them, myocardial damage by disease process seemed to be major contributing factor. 2. Clinical and histological study showed tuberculous origin in 8 cases, nonspecific chronic inflammatory changes in 6 cases and pyogenic infection cases in 5 patients. 2. The postoperative complications were observed in 6 cases, and the most common was cardiac arrhythmia and wound infection. 2. The extent of pericardiectomy should be confined to the left and right ventricles to correct the hemodynamic anomaly in general. The results of this procedure has been satisfactory in 89 percent of the cases. 2. Optimal myocardial function in cases of constritive pericarditis was the key to the successful outcome of this procedure.

기관지확장증의 외과적 치료

이동준,김찬용,Lee, Dong-Jun,Chung, Chan-Yong 대한흉부심장혈관외과학회 1978 Journal of Chest Surgery (J Chest Surg) Vol.11 No.3

Sixty-one bronchiectatic patients were reviewed who were treated by surgical intervention in the Department of Thoracic and Cardiovascular Surgery, Chonnam University Hospital during the recent 14 years from January of 1965 to August of 1978. 1. Various pulmonary resection was performed; lobectomy was 55.5%, lobectomy and segmental resection 20.6%, bilobectomy 13.1%, lobectomy, segmental resection and thoracoplasty 4.9% and pneumonectomy was 3. 2%. 2. The most common associated disease was pulmonary Tbc, its frequency was 47.5% and next was chronic bronchitis [31%]. 3. The postoperative complication was observed in 19.6% [12 cases] and the most common was wound infection. 4. The possibility of recurrence was relatively high in the cases of residual lesion and it needs more intensive medical care. 5. The surgical result was satisfactory in 86.9% (53 cases), slight improvement in 4.9% (3 cases) and the mortality rate was 1.6% (1 case).

저용량 He-Ne 레이저 정맥내(靜脈內) 조사(照射)가 혈중(血中) Lipoprotein(a)에 미치는 영향(影響)

이동준,선중기,최창원,임진훈,Lee, Dong-Joon,Sun, Jung-Ki,Choi, Chang-Won,Lim, Jin-Hoon 대한한방내과학회 2000 大韓韓方內科學會誌 Vol.21 No.5

Objectives : The purpose of study was to investigate the effect of ILlB(intravascular laser irradiation of blood) on serum lipoprotein(a) Methods : The 12 case is diagnosed as cerebrovascular diseases on computed tomograghy. The 18 case is not observed abnormality on computed tomograghy but, they have neurological sign. Blood test was enforced on the first medical examination, The 15 case with plasma lipoprotein(a) greater than 30 mg/dl have been classified into abnormal group and the 15 case of less than 30 mg/dl have been classified into control group. after ten times ILlB, It was observed that the change of plasma lipoprotein(a) and a fibrinogen of blood clotting factor. Conclusions : 1. After ten times ILlB, plasma lipoprotein(a) numerical value was decreased on 13 case of abnormal group. 2. Plasma lipoprotein(a) numerical value was decreased on 5 case of control group. 3. The twenty in fifteen patient's with hyperlipoproteinemias have been fibrinogenemias and after ILIB treatment, in the all of 16 case with hyperfibrinogenemia in the first medical examination to both abnormal and control group, plasma fibrinogen numerical value was decreased.

수분사법으로 제조된 순철분말의 성형성에 미치는 분말크기의 영향

이동준,윤은유,김하늘,강희수,이언식,김형섭,Lee, Dong-Jun,Yoon, Eun-Yoo,Kim, Ha-Neul,Kang, Hee-Soo,Lee, Eon-Sik,Kim, Hyoung-Seop 한국분말야금학회 2011 한국분말재료학회지 (KPMI) Vol.18 No.3

In the current study, the effects of particle size on compaction behavior of water-atomized pure iron powders are investigated. The iron powders are assorted into three groups depending on the particle size; 20-45 ${\mu}M$, 75-106 ${\mu}M$, and 150-180 ${\mu}M$ for the compaction experiments. The powder compaction procedures are processed with pressure of 200, 400, 600, and 800 MPa in a cylindrical die. After the compaction stage, the group having 150-180 ${\mu}M$ of particle size distribution shows the best densification behavior and reaches the highest green density. The reason for these results can be explained by the largest average grain size in the largest particle group, due to the low plastic deformation resistance in large grain sized materials.

Effect of Scutellaria Baicalensis Georgi Extract on Oxidant-Induced Apoptosis in Renal Epithelial Cells

이동준,윤철호,Lee, Dong-Joon,Yoon, Cheol-Ho The Society of Internal Korean Medicine 2004 大韓韓方內科學會誌 Vol.25 No.4

목적 : 黃芩(황금)과 黃芩(황금)의 주요 flavonoid 성분인 baicalein이 신장세뇨관 상피세포에서 산화제에 의한 apoptosis에 미치는 효과를 살펴보고자 한다. 방법 : 신장세뇨관 상피세포주인 opossum kidney (OK) 세포를 유기산화제인 t-butylhydroperoxide (tBHP)에 노출시켜 apoptosis를 일으킨 후 관련된 변화를 관찰하였다. 결과 : tBHP는 농도에 의존하여 apoptosis를 유발시켰는데, 이러한 효과는 黃芩(황금)과 baicalein에 의해 농도 의존적으로 방지 되었다. tBHP에 의한 OK 세포사는 항산화제인 Trolox와 N-acetylcysteine에 의해 방지 되었다. tBHP는 mitogen-activated protein kinase의 subfamily인 extracellular signal-regulated kinase (ERK)를 활성화시켰다. ERK 억제제인 PD98059와 U0126은 tBHP에 의한 세포 사망을 방지하였다. tBHP에 의한 ERK 활성화는 U0126에 의해 억제되었으나 黃芩(황금)과 baicalein에 의해서는 영향을 받지 않았다. 철착염제인 deferoxamine은 tBHP에 의한 세포 사망과 ERK 활성화를 방지하였다. tBHP에 의한 세포 사망은 casopase 억제제인 BOD-U-FMK와 zDEVD-FMK에 의해 방지되었다. 결론 : 黃芩(황금)은 산화제에 의한 세포 사망을 방지하는데, 이는 kinase 억제, 항산화제 역할 및 철착염제의 작용에 기인하지 않았다. 黃芩(황금)의 이러한 효과는 산화제에 의관 신부전 예방 및 치료제로 개발하는데 이용될 수 있는 가능성을 보였다.

거대기종성 폐낭포증 1례 보고

이동준,김상형,Lee, Dong-Jun,Kim, Sang-Hyung 대한흉부심장혈관외과학회 1978 Journal of Chest Surgery (J Chest Surg) Vol.11 No.3

A case of Vanishing lung of right entire lung field in a man of 36 years of age was encountered at Dept. of Chest Surgery of Chonnam University Hospital. His chief complaints were cough, severe dyspnea and chest pain for about 14 years. Right pneumonectomy was done and gross finding was multiple chambered cysts of the right lung with thin epithelium. The review of the literatures was also done.