발생중인 흰쥐 간에서의 Metallothionein 발현에 관한 면역세포화학적 연구

오승한,안영모,신길상,김완종,Oh, Seung-Han,Ahn, Young-Mo,Shin, Kil-Sang,Kim, Wan-Jong 한국현미경학회 2004 Applied microscopy Vol.34 No.3

메탈로사이오닌 (metallothionein: MT)은 시스테인(cysteine)이 다수 포함되어 있고, 저분자량인 단백질로서 중금속이온이나 다양한 세포 독성 인자에 의해 유도되며, 최근 발암과정 (carcinogenesis)이나 혹은 세포분화와 연관하여 활발하게 연구가 이루어지고 있다. 본 연구는 흰쥐를 수정시킨 후 발생과정 또는 출생 후 성장과정 단계에서 태아와 신생 흰쥐의 간 조직 및 세포내 MT의 분포 양상을 조사하고자 하였다. 흰쥐 간 조직내 MT의 분포는 면역조직화학적 방법을 적용하여 광학현미경으로 관찰하였고, 세포내 미세구조적 위치 (localization)는 금 입자 표지를 이용한 면역세포화학적 방법을 이용하여 투과전자현미경으로 관찰하였다. MT는 발생 13일이 경과한 흰쥐 태아의 간에서 처음으로 관찰되기 시작하여, 출생 당일의 신생 흰쥐에서 가장 높게 관찰되었다. 면역 조직화학 및 세포화학적 방법으로 관찰한 결과, MT 염색성은 발생 후기에서 출생후 10일째까지 비교적 높게 나타났다. MT에 대한 양성반응은 난형 세포 (oval cell)들과 간 실질세포 (liver parenchymal cell)들에서 뚜렷하게 존재하였다. 발생과정과 신생 흰쥐의 간 조직에서는 핵과 세포질 양쪽에서 공통적으로 양성 반응을 보였으나, 생후 30일 이후부터 성체에 이르는 시기까지는 세포질에 한정되어 있는 양상을 보였다. 금 입자 표지법에 의한 MT의 세포질내 분포를 보면, 발생 중인 흰쥐 간 세포에서는 핵과 세포질내에 고르게 산재되어 있었다. 즉, 핵내 염색질, 인, 조면소포체 및 cytosol에서도 MT에 대한 면역 금 입자들이 관찰되었으나, 미토콘드리아와 지질 소포 등에서는 거의 관찰되지 않았다. 상기의 결과들은 발생중 혹은 성장중인 흰쥐의 간에서 MT가 점차 증가하는 것으로 요약될 수 있는 것으로서, 이는 MT가 세포들의 증식과 분화에 금속 이온의 저장과 방출 혹은 전사인자 (transcription factor)로서 작용할 수 있음을 암시하는 것으로 판단된다. Metallothionein (MT) is a family of ubiquitous, low molecular weight (6-7 kDa), cysteine-rich protein with a high affinity to metal ions and has no aromatic amino acids and histidine. Some of the known functions of MT include detoxification of heavy metals and alkylating agents and neutralization of free radicals. Also, this protein may affect a number of cellular processes including gene expression, apoptosis, proliferation and differentiation. But, its actual functions are still not clear. The present study was undertaken to examine immunocytochemically the localization of MT in developing rat liver. On the day 11 of gestation, the fetal rat liver has already been formed and contained numerous oval cells with high nuclear cytoplasmic ratio, which were the progenitors of hepatic parenchymal cells, but no reaction products of MT were detected at this time. And then, positive reactions against MT started to appear predominantly in the parenchymal cells of liver from the 13th day after gestation. Reaction products, immunogold particles or brown coloration, were localized at both the nucleus and the cytoplasm of the parenchymal cells, except mitochondria. The intensity of this reaction gradually increased, and exhibited the strongest at birth. The intensity of MT staining and immunogold labelling diminished with growth, and by the 15th day after birth weak positive reaction was observed in the cells. In brief, positive reactions for MT were observed in the oval cells and the parenchymal cells during fetal stage, meanwhile they were present only in the parenchymal cells after birth. The present results suggest that MT possibly involves parechymal cell proliferation and differentiation through the storage or the supply of various metal ions in the developing rat liver.

소형위성 관제용 S-대역 트랜스폰더 설계 및 제작

오승한(Seung-Han Oh),신영섭(Young-Sup Shin),이희민(Hui-Min Yi),홍성용(Sung-Yong Hong) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.4

소형위성 관제용 S대역 프로토타입 트랜스폰더를 상용 부품을 활용하여 설계하였으며, 확장성까지 고려하여 QPSK 변복조 기능을 FPGA를 사용하여 구현하였다. 제작된 트랜스폰더는 RF Front End, RF 변조기, RF 복조기, 그리고 변복조기로 구성된다. 측정결과 트랜스폰더의 수신 비트오율(이하 BER)은 -105 ㏈m의 입력전력에서 1.1Χ10??으로 나타났다. 이러한 방식의 트랜스폰더는 개발기간을 단축할 수 있으며 크기와 무게를 줄일 수 있는 장점이 있다. The S-band Transponder for telemetry and command of small satellite is designed and fabricated as prototype model using COTS(Commercial Off-The-Shelf) components. QPSK modulator and demodulator of transponder is implemented by using FPGA for system extension. The transponder consists of RF Front End, RF Modulator, RF Demodulator, and MODEM. The measured results of fabricated transponder show BER of less than 1.1×10?? at -105 ㏈m input power.

과학기술위성2호 지상관제를 위한 기저대역 제어 시스템 개발

오승한(Sung-Han Oh),오대수(Dae-Soo Oh),오치욱(Chi-Wook Oh) 한국항공우주학회 2006 韓國航空宇宙學會誌 Vol.34 No.1

과학기술위성2호(STSAT-2)는 우리기술에 의해 만들어지는 KSLV 발사체에 실리는 첫 위성이다. 현재 STSAT-2의 관제를 위한 지상관제용 제어시스템(GBC)은 EM(Engineering Model)개발이 완료되어 성능검증 까지 마친 상태이며 최종 납품모델을 제작 중에 있다. GBC는 크게 2가지 기능을 가지는데 하나는 지상 수신안테나들(1.5M, 3.7M, 13M)과 관제 컴퓨터들 사이에 연결패스를 자동으로 만들어 주는 것과 다른 하나는 위성과 데이터를 송수신 하는 것이다. GBC는 거의 모든 기능 (MODEM, PROTOCOL, GBC system control)을 FPGA에 담고 있다. GBC의 FPGA에 구현되어있는 MODEM은 두 개의 uplink FSK modulators(1.2[kbps], 9.6[kbps])와 여섯개의 downlink FSK demodulators(9.6[kbps], 38.4[kbps])로 구성되어있다. 과학기술위성 2호의 GBC는 물리적으로 과학기술위성 1호의 관제 시스템보다 매우 작아졌으며 기능은 더 풍부해진 특징을 가지고 있다. 이 논문은 GBC의 구조, 성능, 실험결과에 관한 것이다. STSAT-2 is the first satellite which will be launched by the first Korean Space Launch Vehicle(KSLV). Ground station Baseband Control system(GBC) is now developed for STSAT-2. GBC has two functions. One is control data path between satellite control computers and ground station antennas(1.5M, 3.7M, 13M) automatically. The other is sending and receiving data between ground station and satellite. GBC is implemented by FPGA(Field-Programmable Gate Array) which includes almost all logic(for MODEM, PROTOCOL and GBC system control). MODEM in GBC has two uplink FSK modulators(1.2[kbps], 9.6[kbps]) and six downlink FSK demodulators(9.6[kbps], 38.4[kbps]). In hardware, STSAT-2 GBC is smaller than STSAT-1 GBC. In function, STSAT-2 GBC has more features than STSAT-1 GBC. This paper is about GBC structure, functions and test results.

Immunogold Labellings and Expression of Metallothionein in Regenerating Rat Liver

안영모,오승한,김호진,이미영,이종화,신길상,김완종,Ahn, Young-Mo,Oh, Seung-Han,Kim, Ho-Jin,Lee, Mi-Young,Lee, Jong-Hwa,Shin, Kil-Sang,Kim, Wan-Jong Korean Society of Electron Microscopy 2005 Applied microscopy Vol.35 No.1

진핵세포 내에 존재하는 metallothionein (MT)은 시스테인 함량이 높은 저분자량의 단백질로서 2가 금속이온들과의 친화력이 높아 중금속에 대한 해독작용, 금속이온의 대사 및 세포분열 등과 관련되어 있다. 본 연구자들은 간 재생능력이 우수한 흰쥐를 실험모델로 하여, 간의 70% 정도를 실험적으로 제거한 후, 간 재생을 유도하는 과정에서 시간 경과에 따라 간세포의 미세구조 변화와 더불어 MT 유전자 발현 및 이 단백질의 세포내 분포를 알아보고자 하였다. 부분 간 절제 후 간 조직이 증식되고 재구성되어 간이 원래의 크기로 재생되는 시간은 1주일 정도가 소요되었다. 재생중인 간세포는 핵대 세포질의 비가 크고, 핵내에 인이 크게 발달하고 크기가 작은 미토콘드리아가 다수 나타났으며, 조면소포체가 잘 발달하고 있었다. MT mRNA는 간 절제 직후부터 증가하기 시작하여 1시간 경과 후에 최대치에 이르렀고, 12시간 이후부터 감소하기 시작하였다. 재생중인 간세포에서 MT에 대한 면역반응은 간 절제 후 12시간이 경과한 군에서 가장 높게 나타났고, 이후 점차 감소하여 8일이 경과한 실험군에서는 정상 대조군과 유사한 정도로 감소하는 것으로 관찰되었다. 또한, 간 재생 초기에는 항-MT 금 입자들이 주로 세포질쪽에 분포하다가 점차 핵내에 존재하는 양이 증가하는 것으로 나타났다. 이러한 결과들은 간 절제 후 보상작용으로 일어나는 세포분열 단계에서 MT가 이 과정에 필요한 요소를 제공하는 역할을 수행하기 때문인 것으로 사료된다. Metallothionein (MT) is a low molecular weight, cysteine-rich, metal-binding, and non-enzymatic protein. The present study was carried out to investigate the expression of MT gene as well as the localization of MT in regenerating rat liver. In partial hepatectomized rats, MT mRNA was detected as early as 1 hr and reached a maximal level by 8 hr after the operation. Thereafter, this level decreased gradually until 24 hr, and it became similar to that of sham control. Meanwhile, time course of MT immunoreactivity using immunogold-labelling revealed that the number of gold particles in hepatocytes increased significantly by 12 hr, but decreased at 48 hr after partial hepatectomy. Ultrastructurally, immunogold particles indicating the presence of MT were distributed in both the cytoplasm and the nucleus of the rat hepatocytes, particularly the particles were distributed at rough endoplasmic reticulum and nucleolus and did not seem to adhere to mitochondria or lysosomes in proliferating hepatocytes. Briefly, high level of MT mRNA expression and the intense immunoreactivity and/or the specific localization of MT was observed during liver regeneration. These results suggest that MT possibly involves hepatocyte proliferation via the storage or the supply of various metal ions in the regenerating rat liver.

섬유의 종류와 함량에 따른 의치상용 레진의 강화효과

유상희(Sang-Hui Yu),오승한(Seung-han Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2009 대한치과재료학회지 Vol.36 No.3

Fiber reinforcement has been used to increase the mechanical properties of denture base resins. However, the reinforcing effect of the various fibers according to the fiber volume was not known. The aim of this study was to evaluate the reinforcing effect of three different fibers according to the fiber content on denture base resin. The heat-polymerized resin (Vertex RS, Dentimax, Netherlands) was used as the matrix. Glass fiber (GL: ER 270FW, Hankuk Fiber Glass, Korea), polyaromatic polyamide fiber (PA: Kevlar-49, Dupont, U.S.A.) and ultra high molecular weight polyethylene fiber (PE: P.E, Dong Yang Rope, Korea) were used to reinforce the denture base resin. The 2.6%, 5.3% and 7.9% volume pre-impregnated fiber were located at the bottom of specimen. The test groups were classified as follows: (1) intact heat-polymerized resin (Control), (2) resin reinforced with glass fibers (GL), (3) resin reinforced with polyaromatic polyamide fibers (PA) and (4) resin reinforced with polyethylene fibers (PE). The test specimens (n=10) of each group were stored in distilled water at 37℃ for 50 hours before test. The flexural strength and modulus were measured by an universal testing machine (Z020, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan?s multiple range test (α=0.05). GL, PA and PE showed significant reinforcing effects on denture base resin. For flexural strength, PA was the highest in 2.6% volume, while GL was the highest in 5.3% and 7.9% volume. For flexural modulus, GL and PA were higher than PE in 2.6% volume, and GL was the highest in 5.3% and 7.9% volume. In this study, all the fibers showed a reinforcing effect on denture base resin. Specially, glass fiber at 5.3% volume ratio showed most effective reinforcing effect on denture base resin in terms of flexural strength and flexural modulus.

초소형위성 군집시스템 개발 현황

이상현(Sang-Hyun Lee),오치욱(Chi-Wook Oh),이철(Chol Lee),김선구(Son-Goo Kim),임철우(Chol-woo Lim),김세연(Se-Yon Kim),오승한(Seung-Han Oh),이훈구(Hungu Lee),김종운(Jong-Un Kim),이동한(Dong-Han Lee),정재헌(Jae-Heon Jeong),채태병(Tae-Byeo 한국항공우주학회 2021 한국항공우주학회 학술발표회 논문집 Vol.2021 No.11

차세대소형위성2호 SAR 제어 비행 SW 개발

박성옥(Sung-Og Park),오승한(Seung-Han Oh),이정수(Jung-Su Lee),김지흥(Jee-Heung Kim),김세연(Se-Yon Kim),구본주(Bon-Ju Gu),이종주(Jong-Ju Lee),박미영(Mi-Young Park),박홍영(Hong-Young Park) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11

초소형위성 군집시스템의 군집운영과 활용

이상현(Sang-Hyun Lee),이철(Chol Lee),오치욱(Chi-Wook Oh),임철우(Chol-Woo Lim),김선구(Son-Goo Kim),김세연(Se-Yun Kim),오승한(Seung-Han Oh),이준찬(Junchan Lee),정효진(Hyo-Jin Jeong),장은진(Eunjin Jang),이훈구(Hungu Lee),강치호(Chi-Ho Kan 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.6

섬유의 종류와 배열방향에 따른 상악 총의치의 강화효과

유상희(Sang-Hui Yu),박다령(Da-Ryeong Park),오승한(Seung-han Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2012 대한치과재료학회지 Vol.39 No.1

The fracture of denture base resin occurs due to repeated loading caused by masticatory forces or accidental dropping. One method strengthening denture base resin is the addition of reinforcing fibers to resin. The aim of this study was to evaluate the effect of glass and aramid fibers according to the fiber orientation on maxillary complete denture. In the study of denture model, maxillary complete denture was fabricated with auto-polymerized resin(Vertex SC). Glass fiber and polyaromatic polyamide fiber (aramid) were used in unidirectional and bidirectional orientation to reinforce the maxillary complete denture. The maxillary complete denture without fibers was used as a control. The flexural strengths, moduli and toughness of the denture were measured with and without silicone maxillary cast, respectively. The specimens of each group were stored in distilled water at 37℃ for 50 hours before test, The flexural strengths, moduli and toughness were measured with a universal testing machine at a crosshead speed of 5 ㎜/min in a three-point bending mode. For flexural strengths, there were no significant differences according to the fiber type and orientation. The flexural strength of bidirectional glass fiber and unidirectional aramid fiber with silicone cast denture were significantly higher than those without silicone cast denture. However, the flexural modulus of unidirectional aramid fiber was significantly higher than those of other experimental groups and the control at test without silicone cast. The flexural modulus of unidirectional aramid fiber and bidirectional glass fiber without silicone cast denture were significantly higher than those without silicone cast denture. For the toughness, the bidirectional glass fiber with silicone cast were significantly higher than those of other experimental groups and the control, with the exception of unidirectional aramid fiber. The toughness of control, bidirectional glass fiber and unidirectional aramid fiber with silicone cast denture were significantly higher than those without silicone cast denture. In this study, bidirectional glass fiber and unidirectional aramid fiber showed the significant reinforcing effect on maxillary complete denture in terms of flexural modulus and toughness.

의치 세정제가 의치상용 레진의 굴곡특성에 미치는 영향

최에스더(Esther Choi),유상희(Sang-Hui Yu),오승한(Seung-Han Oh),배지명(Ji-Myung Bae) 대한치과재료학회 2010 대한치과재료학회지 Vol.37 No.3

The aim of this study was to evaluate the effect of denture cleaners on the flexural properties of denture base resins according to the type and immersion times of denture cleaners. The heat-polymerized resin(Vertex RS, Dentimax, Netherlands) was used as the matrix, and 4 kinds of denture cleaner (Denfix-A, polident, cleadent, and Bony Plus) were tested in this research. The test specimens(n=5) of each group were immersed in 4 kinds of denture cleaners. After 1week, 2, 3, and 4weeks of immersion periods, the test specimens were evaluated by using mechanical strength test. The solution of denture cleaner were exchanged every 24 hours. The flexural strength and modulus were measured by an universal testing machine(Z02 0, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan’s multiple range test(α=0.05). The results of dental cleaner comparison test indicated that there was no significant difference between all test groups and control group regardless of immersion periods(p>0.05). However, the flexural modulus of Polident and Bony Plus groups were significantly lower than that of the control group(p<0.05) on the condition of 2 weeks of immersion. From the results of immersion period comparison test, flexural strength of all experimental group immersed for 1 week were significantly higher than that of the group immersed for 4 weeks(p<0.05). However, the flexural modulus of all experimental groups did not show any significant difference compared to that of control group regardless of immersion periods(p>0.05).