구내 골신장술 후 식립된 전치부 임플란트보철 치험보고

김한석,김명래,이성근,강상원,김기환,김형섭 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.1

Objective : This is to report the effectiveness of intraoral distraction osteogenesis for alveolar augmentation in the extremely atrophied alveolar defects and to review the clinical results of the 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and the trans-oral alveolar distractors(Martin, Germany) were applied in 2 patients with the severe acquired anterior maxillary and mandibular defect. After latent period for 1 week, the osteomized alveolar segments were distracted by 1 ㎜ a day (0.5 ㎜/l turn) for 8 days in case Ⅰ and 0.6 ㎜ a day(0.3 ㎜/l turn) for 10 days in case Ⅱ. The consolidation period was about 8 weeks in each case. Thereafter, 6 titanium threaded implants(Branemark, Restore) were simultaneously installed with removal of distractor. The implants were tested clinically and radiographically. Results : Amounts of acquired alveolar bone were 8 ㎜ in case Ⅰ and 6 ㎜ in case Ⅱ respectively, with the increased width of the ridge crests and soft tissue expansion. Dental implants installated on the augmented alveolar ridges in 8 weeks after distrction were confirmed as in good osseointegration and in good function without any complications. Conclusion : Intraoral distraction osteogenesis can be a good option for alveolar ridge augmentation of the severely atrophied ridges and soft-tissue defects. However, for the better vector control of distracting segments and for anterior esthetics, customized distraction devices could be considered later.

2종의 Ferrite가 혼합된 페라이트/ 고무 복합형 전파흡수체의 전파흡수특성

김한근,이수호,손무헌,박정학,사공 건 東亞大學校 1997 東亞論叢 Vol.34 No.-

In this study, the ferrite/rubber composite microwave absorbers mixed Ni-Zn ferrite and Ni₂Y ferroxplanna were prepared in order to control matching condition. The variation of the material constants(ε*, μ*) and microwave absorbing characteristics were investigated with various ferrite mixing ratio. The material constants of ferrite/rubber composite microwave absorber could be controlled by variation ferrite mixing ratio.

Ni-Zn Ferrite/Rubber복합형 전파흡수체의 정합조건 설계

김한근,사공건,신광호 東亞大學校 1994 東亞論叢 Vol.31 No.1

The demands for microwave absorbing materials and designs are being increased. We have studied about a new design technique to seek for the matching conditions for composite absorbers. The ferrite/rubber composite microwave absorbers were fabricated with Ni-Zn ferrite prepared by coprzcipitation method and silicone rubber. We have figured out the matching conditions(frequency and thickness) through the material constants of the self-maded ferrite/rubber composite absorber by utilizing the matching map and the matching boundary map. We could make a prediction for the matching conditions of ferrite/rubber composite absorber with our developed design technique.

고속 주차시스템 개발에 관한 연구

김순철,박선국,김한근 慶南專門大學 2001 論文集 Vol.29 No.1

하이브리드 시뮬레이티드 에닐링을 이용한 컨테이너 크레인의 최적제어에 관한 연구

김한근,박선국,강정호,이영진,이권순 慶南專門大學 2000 論文集 Vol.28 No.1

진공차단기용 영구자석형 엑추에이터 최적설계

김한균,김중경,이정근,한성진 東亞大學校附設 情報技術硏究所 2005 情報技術硏究所論文誌 Vol.13 No.1

The vacuum interrupter operated by permanent magnet actuator(PMA) gives outlook on improved characteristic, higher reliability and cost price reduction as well as the feature of simple structure and few component. For the anlysis and design of permanent magnetic actuator, not only electric, magnetic and mechanical phenomena but also material properties should be taken into account. Aim of the present paper is modeling of permanent magnet actuator(PMA) used in medium voltage distribution systems and remodeling by permanent magnetic. Coupled finite element method is used to analysis the modeling and we compared with previous PMA model and improved PMA model.

웹페이지 체류시간을 활용한 성향분석 시스템의 설계 및 구현

김창근,탁한호,송태섭 진주산업대학교 농업기술연구소 2007 農業技術硏究所報 Vol.20 No.-

If web users visit highly attractive pages during the navigation pattern, they spend more time over viewing and visiting the pages. This can be important information for electric commerce as well as for website owners to analyze what web sufferer’s tastes are. This paper is designated to find out sufferer’s precise taste by estimating how much time sufferers’ spent in certain sites that they have visited.

흰쥐 난소에서 황체내 큰포식세포에 관한 형태학적 연구 : 면역조직화학적 및 투과전자현미경적 연구

김원식,한승로,조근자,김수일,박창식 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

황체는 임신의 수립과 유지에 필수적인 일시적인 내분비샘으로, 주기능을 발정주기의 생리적 기간을 결정하고 성공적인 임신을 달성하는데 결정적인 프로게스테론의 생산이다. 황체의 기능은 뇌하수체 gonadotropin 뿐만 아니라 황체내 큰포식세포에서 분비되는 TNF-α를 포함한 몇가지 cytokines에 의해 조절되는 것으로 알려져 있다. 본 연구에서는 흰쥐 (Sprague-Dawley계통)에서 생식주기별 황체내 큰포식세포의 변화를 면역조직화학적 및 투과전자현미경적으로 관찰 비교하였다. 본 연구에서 흰쥐 황체에서 큰포식세포는 배란기,임신기 및 출산후기 등 모든 시기에 나타나고,그 수와 면역반응성은 배란기에 가장 컸고 출산후기,임신기 순으로 나타났다. 아울러 투과전자현미경 관찰에서는 황체내 큰포식세포를 세포체가 가늘고 돌기가 긴 비포식성 큰포식세포와 포식성 공포와 지방소체들을 많이 함유한 포식성 콘포식세포로 분류할 수 있었다. 본 연구를 통해 황체내 콘포식세포는 발정주기에 따라 그 수나 면역반응성이 다르며,황체퇴화가 활발히 진행되는 배란기와 출산후기에 면역반응성이 증가하고 포식성 큰식세포들이 나타난 것은 큰포식세포에서 TNF-α 와 같은 cytokines의 분비를 활발히 일으키고 그들이 황체세포들의 세포자멸사를 유발,촉진하고 또한 세포자멸 사소체들을 포식,제거하는 방법으로 황체퇴화를 유도하여 정상적인 발정주기를 유지하기 위한 기전으로 생각 되고,임신기에 큰 포식세포의 수와 면역반응성이 작아지고 비포식성 큰포식세포가 주를 이루는 것은 이들이 TNF-α 동의 cytokines 분비를 통해 그들이 황체자극효과를 나타내 황체의 기능을 유지,촉진하는데만 관여하고,한편으로는 황체에서 생산되는 프로게스테론에 의한 큰포식세포 억제작용 때문인 것으로 생각된다. Macrophages in the corpus luteum have many important roles during the periods of functional development and luteal regression. Not only phagocyte the apoptotic luteal cells, but also they secrete many cytokines and exert their effects via autocrine/paracrine actions. In this study, we investigated the changes of number and immunoreactivity of macrophages at various developmental periods of the corpus luteum in the rat ovary. The rats (Sprague- Dawley strain, female) at age of 8 weeks (ovulatory period), GD 6 (pregnant period), and postpartum 5 days (postpartum period) were sacrificed under ether anesthesia and obtained both ovaries, one used for macrophages immunohistochemistry and the other used for TEM. The results were as follows; I. In the corpora lutea of the rat, macrophages were observed all the developmental periods including ovulatory, pregnant and postpartum periods. 2. In the corpora lutea of the rat, number of macrophages was highest in the ovulatory period, and decreased at postpartum period and pregnant period in order. The immunoreactivity of macrophages was high at ovulatory period, moderate at postpartum period, and low at pregnant period. 3. In TEM observations, two types of macro phages were observed: One type was non-phagocytic macrophage and the other type was phagocytic macrophage. Phagocytic macrophages were observed in the corpora lutea at ovulatory and postpartum periods and contained apoptotic bodies, phagocytic vacuoles and many lipid droplets. Non-phagocytic macrophages were observed in the corpora lutea at pregnancy period and showed slender cell body with long cytoplasmic processes and contained no apoptotic bodies. In the rat, the number and the degree of immunoreactivity of macrophages in the corpus luteum varied with the changes of functional state of the corpus luteum. It was suggested that the main function of the macrophages at the ovulatory and postpartum periods was elimination of apoptotic luteal cells and that at pregnancy period was autocrine/paracrine action. Ultrastructurally, two types, phagocytic and nonphagocytic types, of macrophages confirmed. These results will provide valuable informations on the study of the role macrophages during development and regression of corpus luteum.

방사선 조사에 의한 흰주 난포의 퇴축과 난포세포의 방사선 감수성

김수일,한승로,조근자,허대영,이영호,조문준,김무강,김원식 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

The aim of this study were to investigate radiation-induced atresia and radiation susceptibility in the rat ovary morphologically. Female rats (Sprague Dawley strain) of 4 weeks old were irradiated with dose of 4 Gy and 8 Gy, and sacrificed at hour 6, 12, and 24 after radiation. The H & E stain, the TUNEL method (ApopTag kit) and transmission electron microscopy (TEM) were used. In light microscopic observation, the number of atresia of ovarian follicles were increased significantly at 6h after irradiation (p<0.01). There was no significant difference between 4 Gy and 8 Gy irradiated groups. In TEM observation, granulosa cells in radio-sensitive follicles were characterized by several structural features including condensation of nuclear chromatin granules, nuclear fragmentation and apoptotic body formation. An apoptotic cell is observed to have been phagocytosed by a normal granulosa cell. Granulosa cells in radio-resistant follicles were characterized by several structural features including nuclear indentation, partial condensation of chromatin granules, mitochondrial swelling, dilatation of RER cisterns, accumulation of dense irregular masses, accumulation of lipid droplets, and increased lysosomal bodies. Number of gap junctions between granulosa cells were decreased, and intercellular space were widen than that of control animals. These findings were prominent at 6h after irradiation and were diminished at 12h and 24h after irradiation. With these results, it was concluded that radiation-induced follicular cell apoptosis and ovarian follicular atresia in rat ovary increased considerably at 6h after irradiation. Further studies are needed to reveal the more extensive differences between radiosensitive and radioresistant follicular granulosa cells.

인산 칼슘을 사용한 수산화아파타이트 시멘트의 응결·경화 특성에 관한 연구

김한엽,박찬근,송태웅 경남대학교 신소재연구소 1996 論文集 Vol.6 No.-

습식법이나 수열법으로 합성한 hydroxyapatite(HAp)의 분말을 성형, 열처리한 소결체는 지금까지 알려진 바이오 세라믹스 중 생체친화성이 가장 우수한 것으로 입증되고 있으나 소결에 따르는 제조상의 몇가지 문제점을 안고 있다. 본 연구에서는 소결에 의하지 않고 tetracalcium phosphate(TTCP)분말과 dicalcium phosphate dihydrate(DCPD) 분말의 혼합물로 만든 paste를 용해·침전반응으로 응결·경화시켜 직접 HAp 경화체를 얻고, 이때 몇가지 변수가 HAp의 생성과 응결 및 경화특성에 미치는 영향을 검토하였다. TTCP와 DCPD로 조합한 시멘트의 수화반응생성물은 HAp 경화체였으며 이의 미소결정의 interlocking에 의해 응결·경화 하였다. 반응온도 및 HAp 종자의 첨가는 주로 초기단계의 반응속도에 영향을 주었다. 50℃에서의 HAp 생성 반응은 24시간 이내에 거의 완료되었다. Hydroxyapatite ceramics, one of the excellent biocompatible materials, are usually prepared by sintering of hydroxyapatite powders from wet chemical methods. But some problems caused by sintering process are still remained. In this study, instead of powder sintering methods. hardened bodies of hydroxyapatite were prepared by self-hardening reaction of cement paste composed of powdered tetracalcium phosphate(TTCP) and dicalcium phosphate dihydrate(DCPD). Some effects of seeding, reaction temperature on setting and hardening properties were investigated . The hydration products of the hardened paste were composed of finely-crystallized hydroxyapatite which causes setting and hardening by interlocking themselves. Self setting and hardening reaction are accelerated by elevating reaction temperature and addition of hydroxyapatite powders as a seeding materials. The hydration reaction of the paste. at 50C. was nearly finished within 24 hours after mixing with water.