n-Type Silicon의 電氣傳導度에 關한 硏究

曺喆銶 空軍士官學校 1984 論文集 Vol.19 No.-

n-Type Silicon으로 시료를 제작하였으며 78˚K에서 460˚K까지 온도의 함수로 전기전도도를 구하였다. 440˚K이상의 온도에서 전기전도도는 σ_0=Aexp(-(ΔE/2kT))와 같이 지수함수적으로 변화하였으며 78˚K와 440˚K 사이에서는 온도증가에 따라 전기전도도는 감소하였다. 또한 Energy Gap은 1.16eV를 구하였는데 실제 300˚K에서 1.24eV인 값과 비슷한 결과를 얻었다. 모든 결과는 이론과 다른 연구자의 결과와 일치하였다. Samples were prepared from n-type silicon, and electrical conductivity was obtained as a function of temperature from 78˚K to 460˚K. The conductivity shows an exponential behavior of the form σ_0=Aexp(-(ΔE/2kT)) above 440˚K and decreases between 78˚K and 440˚K as temperature increases. And energy gap was about 1.16eV, which is close to 1.14eV at 300˚K All results are consistent with the customary simple theoretical model and other researcher’s.

Bauxite로부터 습식 산처리법에 의한 알루미나 분체의 제조 및 그 이용에 관한 연구(III) : Aluminum Hydrate Gel의 분산에 의한 알루미나 분체의 소결성 향상

조철구,정원도,배원태 한국세라믹학회 1993 한국세라믹학회지 Vol.30 No.4

Dispersant was used to avoid the agglomeration of aluminum hydrate precipitate and improve the sinterability of calcined alumina powder. The mean particle size of the aluminum hydrate precipitates was 0.26${\mu}{\textrm}{m}$ and 0.44${\mu}{\textrm}{m}$ when ball-milled with and without dispersant, respectively. After calcination at 110$0^{\circ}C$ for 5 hours, the size of the alumina powder without dispersant increased to 0.84${\mu}{\textrm}{m}$, while with dispersant slightly decreased to 0.22${\mu}{\textrm}{m}$. The most thermally active alumina powder was obtained from the sample calcined at 110$0^{\circ}C$ for 5 hours with the 1% dispersant concentration. Using the calcined alumina powder at the above optimized condition, the specimen showed fired density of 3.94g/㎤, 4-point MOR of 364MPa, and KIC of 3.26MPam1/2 after sintered at 155$0^{\circ}C$ for 3 hours.

악성 타액선 종양의 방사선 치료 성적에 대하여 -원자력 병원의 10년 경험 ($1975.1{\sim}1984.12$)-

조철구,고경환,류성렬,박영환,박우윤,심윤상,오경균,Cho Chul Koo,Koh Kyoung Hwan,Yoo Seong Yul,Park Young Hwan,Park Woo Yoon,Shim Young Sang,Oh Kyung Kyoon The Korean Society for Radiation Oncology 1990 Radiation Oncology Journal Vol.8 No.1

1975년 1월부터 1984년 12월까지 원자력병원 치료 방사선과에서 악성 타액선 종양으로 방사선 치료를 받은 58명의 환자를 대상으로 하여 이들의 생존율을 후향적으로 분석하였다. 이들은 수술후 재발했거나, 수술이 불가능한 환자들이었다. 58명의 환자중 mucoepidermoid carcinoma를 가진 환자가 $43.1\%$, adenoid cystic carcinoma를 가진 환자는 $41.3\%$였다. 주 타액선 종양의 5년 보험생존율은 $68.2\%$, 10년 생존율은 $31.8\%$였으나, 무병생존율은 각각 $43.2\%\;13.0\%$로써 치료 후 재발된 상태에서도 비교적 오래 산다는 것을 알 수 있었다. TNM staging에 의한 생존율도 $T_1$의 5년 생존율이 $86.5\%,\;T_2+T_3$가 $40.0\%,\;T_4$가 $0\%$로, T stage가 높아지면 질수록 생존율도 현저히 감소하였다. 병리조직학적 관점에서 볼 때, adenoid cystic carcinoma의 5년 무병생존율은 $40.1\%$로써, mucoepidermoid ca.의 $49.8\%$보다 낮았으나, 전체적인 생존율은 $77.3\%$로써, mucoepidermoid ca.의 $51.5\%$보다 현저히 높았다. 따라서, adenoid cystic carcinoma는 치료실패후 병을 가진 상태에서도 상당 기간 생존할 수 있다는 것을 알았으며, 평균 생존기간은 2년 이었다. 또한 mucoepidermoid ca.인 경우에는 세포의 분화정도에 따라 생존율이 달라졌는데, 저등도 분화세포의 5년 생존율이 $78.8\%$로 고등도 분화세포의 $38.2\%$보다 거의 2배나 높았다. 암의 위치와 성별에 따른 생존율의 차이는 없었다. Minor salivary gland tumor는 6명으로 5년 보험생존률은 $32.3\%$였다. 따라서 주 타액선 종양의 생존율에 영향을 끼칠 수 있는 예후 인자는 1) 병리조직학적 세포종류, 2) T와 N stages (AJCC), 3) mucoepidermoid carcinoma에 있어서 분화 정도 였다. Retrospective analysis of survival rates was undertaken in the patients of 58 cases treated with conventional radiation therapy for malignant salivary gland tumors between January 1975 and December 1984 in Korea Cancer Center Hospital (KCCH). They were patients whose long-term follow-up was possible and who had refused surgery or had had recurrences postoperatively. Out of 58 patients, 25 patients ($43.1\%$) had mucoepidermoid carcinomas and 24 patients ($41.3\%$) adenoid cystic carcinoma. Total actuarial survival rates at 5 years and 10 years were $68.2\%\;and\;31.8\%$ respectively, but disease-free survival rates, $43.2\%\;and\;13.0\%$, respectively. According to TNM stage, the survival rates at 5 years were $86.5\%$ in $T_1,\;40.0\%\;in\;T_2+T_3,\;and\;0\%\;in\;T_4$. In terms of histologic types, 5 years disease-free survival rate of adenoid cystic carcinomas ($40.1\%$) was lower than that of mucoepidermoid carcinomas ($49.8\%$) but overall survival rate ($77.3\%$) was much higher than that of mucoepidermoid carcinomas ($51.5\%$). There-fore, we concluded that the patients, who had had disease after failure of treatment, could survive during a certain period of time and their alive times were 2 years on the average. There was a difference in survival rates in the mucoepidermoid carcinomas in terms of histological grade of differentiation and it was a arbiter in prognosis: 5 YSR of low-grade was $78.8\%$ and higher 2 times than that of high-grade. There was no difference in survival rates according to location and sex. The number of patients having minor salivary gland tumors was 6 cases and their actuarial 5 YSR was $32.3\%$. Consequently, prognostic factors which influence the survival rates of patients with malignant salivary gland tumors are thought to be 1) histological subtypes 2) T and N staging (AJCC) 3) histological grade, especially in mucoepidermoids.

Aedes Vexans Nipponii에서의 日本腦炎 바이러스 分離

趙澈九,李鎬汪 고려대학교 의과대학 1974 고려대 의대 잡지 Vol.11 No.2

It has been widely known that Culex tritaeniorhynchus is the main vector of Japanese encephalitis (JE) and the report is that Japanese encephalitis virus (JEV) was isolated from Culex pseudovishnui and Culex gelidus in a part of Southeast Asia. In this study, 33,381 Aedes vexans nipponii were collected in the suburbs of Seoul in summer of 1967 and 1968 and the existence of Japanese encephalitis virus and unknown virus were investigated. Suspensions of 19,006 mosquitoes, 266 lots in 1967, 14,275 mosquitoes, 240 lots in 1968, total 500 lots were investigated and made advantage of porcine kidney and chick embryo cells a s the detector system for the isolation of viruses. In the results, 4 strains of Japanese encephalitis virus could be isolated from Aedes uexans nipponii, 2 strains in July, 1967 and 2 strains in August, 1968. The most prevalent species of mosquitoes in summers of 1967 and 1968 is A. vexans nipponii (70~80%), C. tritaeniorhynchus and (15%) C. pipiens (6~8%) in order.

우심실양분증의 심장영화촬영상에 관한 고찰

조철구 대한영상의학회 1983 대한영상의학회지 Vol.19 No.4

Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and atopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows : 1. Among 14 cases, 6 cases were male and 8 cases female. Age distribution was from 4 years to 36 years. 2. In chest X-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressue chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricule was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catherterization is an essential procedure.

성문암(聲門癌) 방사선치료(放射線治療) 20년(年) 성적(成績)

조철구,고경환,유성열,Cho Chul-Koo,Koh Kyoung-Hwan,Yoo Seong-Yul 대한두경부종양학회 1988 대한두경부 종양학회지 Vol.4 No.1

To evaluate the result of radiation therapy for twenty years experience, a total of 115 cases of pathologically proven glottic carcinoma had been analyzed according tot survival respectively. All the patients had been treated with radiation therapy in curative intent using Co-60 teletherapy machine. The results are as follows: 1) Accoridng to sex, 5YSR & 10YSR were 58.7% and 50.4% in male patients, and 80.0% & 72.0% in female. 2) According to T staging, 5YSR & 10YSR were 83.4% & 83.4% in T1, 69.2% & 60.0% in T2, 34.3% & 21.8% in T3, 32.0% & 0% in T4. 3) According to N staging, 5YSR & 10YSR were 63.8% & 59.2% in node-negative groups, and 30.7% & 15.4% in node-positive groups. 4) According to the histologic grade, 5YSR & 10YSR were 66.8% & 57.6% in G1, 61.3% 54.3% in G2, and 35.0% 35.0% in G3. 5) According to AJC staging, 5YSR & 10YSR were 83.4%% 83.4% in stage I, 72.0% & 62.7% in stage II, 36.8% & 28.3% in stage III, and 14.3% & 7.1% in stage IV. 6) In summary, 5YSR & 10YSR wre 60.4% & 52.8% in glottic carcinoma.

방사선 조사에 의한 DNA Double Strand Breaks의 생성 및 회복에 미치는 인삼 알칼로이드 분획의 효과

조철구,김태환,류성렬,고경환,김미숙,김정희,김성호,윤형근,지영훈,Cho Chul Koo,Kim Tae Hwan,Yoo Seong Yul,Koh Kyoung Hwan,Kim Mi Sook,Kim Jeong Hee,Kim Seong Ho,Yoon Hyung Keun,Ji Young Hoon 대한방사선종양학회 1995 Radiation Oncology Journal Vol.13 No.2

Purpose : To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks (dsb) formation and repair in murine lymphocytes Materials and Methods : We used the neutral filter elution technique to assay $^{60}Co\;{\gamma}$ ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluating the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with Phytohemagglutinin (PHA, 2 u g/ml) to label $^3[H]-thymidine.$ Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at $0^{\cdot}C$ in the alkaloid fraction-treated group and elution procedure was performed at PH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). Results: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2 15, compared to control group Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About $30\%$ of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alkaloid fraction had a great effect on the second slow component of repair; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. Conclusion: Neutral filter elution assay Proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors around the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction wil be needed in the near future.

암의 해결사, 방사선의학의 힘

조철구,Jo, Cheol-Gu 한국원자력산업회의 2007 원자력산업 Vol.27 No.8

Aedes Vexans Nipponii에서의 日本腦炎 바이러스 分離

趙澈九 고려대학교 의과대학 1974 고려대학교 의과대학 잡지 Vol.11 No.2

명사칼럼-방사선과 함께하는 건강관리

조철구,Jo, Cheol-Gu 한국건강관리협회 2007 건강소식 Vol.31 No.12