열전도성 고분자와 Al재질의 Heat Sink 방열 성능 비교 분석

최두호,최원호,조주웅,박대희,Choi, Doo-Ho,Choi, Won-Ho,Jo, Ju-Ung,Park, Dae-Hee 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.2

The purpose of this study is examining thermal dissipation materials for the lighting and radiate efficiency improvement of 8W LED and confirming the properness of the thermal dissipation materials for LED heat sink. Solid Works flow simulation on 8W class COB was done based on the material characteristics of thermal conductive polymer materials. According to the result of simulation, Al had better thermal dissipation performance than PET. Highest temperature was $7.6^{\circ}C$ higher while lowest temperature was $7.8^{\circ}C$ lower. The test on the heat sinks made by the materials, highest temperature was $4.1^{\circ}C$ higher and lowest temperature was $3.9^{\circ}C$ lower. It is possible to confirm that Al heat sink has better thermal dissipation efficiency because it has better dispersion of heat generated at junction temperature and less heat cohesion. The weight of PET heat sink was reduced than Al heat sink by 46.9% by the density difference between Al and PET. In conclusion, thermal dissipation performance of thermal conductive polymer is lower than Al material however, it is possible to lighting heat sink because thermal conductive polymer has better formability, has lower specific weight and enables various design options.

식용버섯과 진균 교차 배양을 활용한 플라스틱 필름의 생물학적 분해효과

최두호,이은지,안기홍,이강효,Doo-Ho Choi,Eunji Lee,Gi-Hong An,Kang-Hyo Lee 한국버섯학회 2024 한국버섯학회지 Vol.22 No.1

Plastics are widely used in industries in human society and because of their structural stability, degradation is a serious global issue. To estimate the degradation of plastic, 31 edible mushrooms were cultured with the selected plastic films (polyethylene [PE], polystyrene [PS], and poly(ethylene terephthalate) [PET]) for 3 months at 25 ℃. Measuring the weight of the films showed that four species of mushrooms, namely Porostereum spadiceum, Ganoderma lucidum, Coprinellus micaceus, and Pleurotus ostreatus, exhibited the highest degrees of plastic degradation. In addition, the mushrooms and fungi that exhibited the most significant plastic degradation were cross-cultured to promote this degradation. As a result, cross-cultivation of G. lucidum and Aspergillus niger showed a weight loss of 2.49% for the PET film. For the PS film, Aspergillus nidulans showed a weight loss of 4.06%. Cross-cultivation of A. nidulans and C. micaceus, which showed a weight loss of 2.95%, was noted as an alternative for PS biodegradation, but is harmful to humans. These bio-degradation effects of edible mushroom will contribute to the development of alternatives for eco-friendly plastic degradation.

한국의 젊은 여성유방암 환자에서 BRCA 배선유전자 돌연변이는 예후인자인가?

최두호,이민혁,Choi Doo Ho,Lee Min Hyuk,Haffty Bruce G. The Korean Society for Radiation Oncology 2003 Radiation Oncology Journal Vol.21 No.2

목적: 한국인 젊은 여성 유방암 환자에서 유방암 유전자 (BRCA)가 예후인자가 될 수 있는지 알아보기 위하여 본 연구를 시행하였다. 대상 및 방법: 대학병원에서 치료를 받은 환자 중에서 유방암이나 난소암의 가족력과 관계없이 40세 이하의 환자를 선택하였다. 환자의 나이는 18~40세이었고 중앙값은 34.5세이었다. 환자의 말초혈액에서 림프구를 모아 DNA를 추출하였으며 BRCA1과 BRCA2의 모든 염기 중에서 기능과 관계 있는 부위의 DNA를 직접염기서열 결정방식으로 검사하였다. 조직표본 검사가 가능한 환자는 면역화학조직검사를 시행하였다. 대상 및 방법: 60명의 환자 중에서 유방암 발생과 직접 관계가 있는 돌연변이가 11개(18.3%) 있었고(BRCA1 6명, BRCA2 5명), 의미를 알기가 곤란한 돌연변이가 7개 있었으며 반 수 이상의 돌연변이는 이제까지 보고되지 않은 것이었다. 그리고 대부분의 돌연변이 환자는 유방암이나 난소암의 가족력이 관찰되지 않았다. 유방암 유전자 돌연변이 환자는 한 명도 치료의 실패가 없었으며 한 면에서 반대측 유방암이 발생하였다. 7년 무병 생존율은 돌연변이 환자에서 50%, 돌연변이와 관계가 없는 환자에서 79%이었고 차이는 없었다. BRCA 관련 종양에서 에스트로젠, 프로제스테론 수용체 음성의 비율이 높았으며 조직학적 분화도가 낮았으나 예후는 비교대상에 비해 나쁘지 않았다. 결론: 한국의 젊은 여성 유방암 환자는 예후가 인자가 있어도 재발률이 낮았으며 유전자 돌연변이 이환율이 높았으나 암의 발현율은 상대적으로 낮은 것으로 추정되었다 이 결과를 확인하기 위해 더 많은 환자 집단과 오랜 추적기간의 연구가 필요하다. Purpose: The purpose of this study was to determine if there were prognostic differences between BRCA related and BRCA non-related Korean patients with early-onset breast carcinomas. Materials and Methods: Sixty women who had developed breast cancers before the age of 40, and who were treated at the Soonchunhyang University Hospital, were studied independently of their family histories. The age range was 18 to 40 with a median of 34.5 years. Lymphocyte specimens from peripheral blood were studied for the heterozygous mutations of BRCA1 and BRCA2 using direct sequencing methods. Immunohistochemistry was peformed on the paraffin-embedded tissue blocks that were available. Results: Eleven deleterious mutations (18.3%, 6 in BRCA1 and 5 in BRCA2) and 7 missense mutations of unknown significance (11.7%), were found among the 60 patients. More than half of the mutation were novel, and were not reported in the database. Most of the BRCA-associated patients had no history of breast cancer. No treatment related failures were observed in the BRCA carriers, with the exception of one patient that had experienced a new primary tumor of the contralateral breast. The seven year relapse free survival rate were 50 and 79% In the BRCA carrier and BRCA negative patients, respectively. Although the expression of estrogen and progesterone receptors were less common, and histological features more aggressive, in the BRCA associated tumors, the outcome of the patients with BRCA mutations was not poorer than that on the patients without deleterious mutations. Conclusion.: Despite the BRCA mutation carriers having adverse prognostic features, the recurrence rate was relatively lower than that in the BRCA non-carrying Korean patients wi4h early-onset breast carcinomas. In addition, although the prevalence of the BRCA mutation in Korean patients was higher than that in white patients, the penetrance of the cancer seemed to be relatively low in Korean women carrying BRCA mutations. A large population based study of the BRCA mutation, with a long-term follow-up of the study patients will be required to confirm these results.

국내 봉화 송이 자생지 내 균환 유래 토양세균의 송이균사체 생장촉진 효과

최두호,이은지,이강효,안기홍,Doo-Ho Choi,Eunji Lee,Kang-Hyo Lee,Gi-Hong An 한국버섯학회 2024 한국버섯학회지 Vol.22 No.1

As a member of ectomycorrhizal fungi, Tricholoma matsutake has a symbiotic relationship with its host, Pinus densiflora. To cultivate T. matsutake artificially, the co-cultivation of T. matsutake mycelia and bacteria from shiro was introduced. In this study, bacteria were isolated from soil samples in Bonghwa-gun, and seven bacterial isolates (B22_7_B05, B22_7_B06, B22_7_B07, B22_7_B08, B22_7_B10, B22_7_B13, and B22_7_B14) promoted the growth of T. matsutake mycelia (147.48, 232.11, 266.72, 211.43, 175.17, 154.62, and 177.92%, respectively). Sequencing of the 16S rRNA region of the isolated bacteria was performed. B22_7_B05 and B22_7_B10 were identified as Bacillus toyonensis, B22_7_B06 and B22_7_B08 as Paenibacillus taichungensis, B22_7_B07 and B22_7_B14 as P. gorilla, and B22_7_B13 as P. odorifer. These bacterial isolates were associated with the shiro community and are expected to contribute to the cultivation of T. matsutake.

국내 양양 송이 자생지 내 균환 유래 토양미생물과 송이균사체 생장촉진 효과

최두호,이은지,이강효,안기홍,Doo-Ho Choi,Eunji Lee,Kang-Hyo Lee,Gi-Hong An 한국버섯학회 2024 한국버섯학회지 Vol.22 No.1

Tricholoma matsutake is a traditional favorite food in East Asia, cultivated in fairy rings called "shiro," which are found near Pinus densiflora. For effective artificial cultivation of Tri. matsutake, microorganisms from symbiotic fairy rings are co-cultivated. In this study, one bacterial isolate (Y22_B35) and two fungal isolates (Y22_F64 and Y22_F68) displayed growth-promoting effects on Tri. matsutake mycelium (158.47, 125.00, and 122.26% enhanced growth, respectively). For identification, 16S rRNA or ITS regions from the microorganisms¡¯ genomes were sequenced. Other sequences, including BenA, CaM, and RPB2 were sequenced in the fungal isolates. The bacterial isolate Y22_B35 was identified as Bacillus cereus. Y22_F64 and Y22_F68 were identified as Umbelopsis nana and Aspergillus parvulus, respectively. To identify the effects of the dominant microorganisms on Tri. Matsutake cultivation, metagenomic analyses were performed. Discovery of these Tri. matsutake mycelium growth-promoting microorganisms and metagenomics analyses are expected to contribute to our understanding of Tri. matsutake fruiting body growth and construction of biomimicry.

도시조직과의 연계성 확보를 위한 공동주택 계획기법에 관한 연구 - 강일2지구 공동주택 현상안 분석을 중심으로 -

최두호,이주형,Choi, Doo-Ho,Lee, Joo-Hyung 한국주거학회 2006 한국주거학회 논문집 Vol.17 No.6

In the planning process, there are five directions to planning residential sites. Firstly, the site must be planned to allow continuity with the city space, or created to conform to the city structure. Secondly, plans for community space and programs as well as convenience facilities must coexist in the road space. Thirdly, in terms of view, the site must be planned in territories to secure identity of the site. Fourthly, in terms of the environment, the site should utilize the natural environment. Lastly, in terms of infrastructure, the site should include a pedestrian-centered road system as well as establishing city infrastructure facilities for a combined planning in the municipal dimension. So far we have looked at planning methods for an apartment site that can be integrated into the existing city. The study into five elements to planning a large-scale apartment site, context, community, landscape, environment and infrastructure, and their relationship among each other must continue on.

뉴타운지구내 건축밀도 및 층수기준 설정에 관한 연구

최두호(Choi, Doo-Ho),이주형(Lee, Joo-Hyung) 한국도시설계학회 2006 도시설계 : 한국도시설계학회지 Vol.7 No.4

Is the BRCA Germline Mutation a Prognostic Factor in Korean Patients with Early-onset Breast Carcinomas?

최두호(Doo Ho Choi),이민혁(Min Hyuk Lee),Bruce G. Haffty 대한방사선종양학회 2003 Radiation Oncology Journal Vol.21 No.2

목 적: 한국인 젊은 여성유방암 환자에서 유방암 유전자 (BRCA)가 예후인자가 될 수 있는지 알아보기 위하여 본 연구를 시행하였다. 대상 및 방법: 대학병원에서 치료를 받은 환자중에서 유방암이나 난소암의 가족력과 관계없이 40세이하의 환자를 선택하였다. 환자의 나이는 18˜40세이었고 중앙값은 34.5세이었다.환자의 말초혈액에서 림프구를 모아 DNA를 추출하였으며 BRCA1과 BRCA2의 모든 염기 중에서 기능과 관계있는 부위의 DNA를 직접염기서열 결정방식으로 검사하였다.조직표본 검사가 가능한 환자는 면역화학 조직검사를 시행하였다. 결 과: 60명의 환자 중에서 유방암 발생과 직접 관계가 있는 돌연변이가 11개(18.3%)있었고(BRCA1 6명, BRCA 25명),의미를알기가 곤란한 돌연변이가 7개 있었으며 반 수 이상의 돌연변이는 이제까지 보고되지 않은 것이었다.그리고 대부분의 돌연변이 환자는 유방암이나 난소암의 가족력이 관찰되지 않았다.유방암 유전자 돌연변이 환자는 한 명도 치료의 실패가 없었으며 한 명에서 반대측 유방암이 발생하였다. 7년 무병 생존율은 돌연변이 환자에서 50%, 돌연변이와 관계가 없는 환자에서 79%이었고 차이는 없었다. BRCA 관련 종양에서 에스트로젠, 프로제스테론 수용체 음성의 비율이 높았으며 조직학적 분화도가 낮았으나 예후는 비교대상에 비해 나쁘지 않았다. 결 론: 한국의 젊은여성 유방암 환자는 예후가인자가 있어도 재발률이 낮았으며 유전자 돌연변이 이환율이 높았으나 암의 발현율은 상대적으로 낮은 것으로 추정되었다.이 결과를 확인하기 위해 더 많은 환자 집단과 오랜 추적기간의 연구가 필요하다. Purpose: The purpose of this study was to determine if there were prognostic differences between BRCA related and BRCA non-related Korean patients with early-onset breast carcinomas. Materials and Methods: Sixty women who had developed breast cancers before the age of 40, and who were treated at the Soonchunhyang University Hospital, were studied independently of their family histories. The age range was 18 to 40 with a median of 34.5 years. Lymphocyte specimens from peripheral blood were studied for the heterozygous mutations of BRCA1 and BRCA2 using direct sequencing methods. Immunohistochemistry was performed on the paraffin-embedded tissue blocks that were available. Results: Eleven deleterious mutations (18.3%, 6 in BRCA1 and 5 in BRCA2) and 7 missense mutations ofunknown significance (11.7%), were found among the 60 patients.Morethan half of the mutation were novel, and were not reported in the database. Most of the BRCA-associated patients had no history of breast cancer. No treatment related failures were observed in the BRCA carriers, with the exception of one patientthat had experienced a new primary tumor of the contralateral breast. The seven year relapse free survival rate were 50 and 79% in the BRCA carrier and BRCA negative patients, respectively. Although the expression of estrogen and progesterone receptors were less common, and histological features more aggressive, in the BRCA associated tumors, the outcome of the patients with BRCA mutations was not poorer than that of the patients without deleterious mutations. Conclusion: Despite the BRCA mutation carriers having adverse prognostic features, the recurrence rate was relatively lower than that in the BRCA non-carrying Korean patients with early-onset breast carcinomas. In addition, although the prevalence of the BRCA mutation in Korean patients was higher than that in white patients, the penetrance ofthecancer seemed to be relatively low in Korean women carrying BRCA mutations. A large population basedstudy of the BRCA mutation, with a long-term follow-up of the study patients will be required to confirm these results.

Radiotherapy Results of Brain Astrocytoma and Glioblastoma Multiforme

최두호(Doo Ho Choi),김일한(Il Han Kim),하성환(Sung Whan Ha),지제근(Je Geun Chi) 대한방사선종양학회 1988 Radiation Oncology Journal Vol.6 No.2

성상세포종과 교아세포종으로 1979년부터 1985년까지 7년간 서울대학교 치료방사선과에서 수술후 방사선치료를 시행한 49명의 호나자에 대해 후향적 분석을 시행하여 다음과 같은 결과를 얻었다. 1. 3년 전체 생존율은 grade Ⅰ, Ⅱ, Ⅲ 성상세포종에 대해 각각 85.7%, 44.6%, 23.1%였으며, 교아세포종의 1년 및 2년 전체생존율은 각각 54.5%, 27.3%였다. 2. 종양의 분화도, 환자의 나이, 병소의 위치, 절제정더 등이 예후에 영향을 미치는 인자로 나타났다 A retrospective analysis was performed on 49 patients with astrocytoma of glioblastoma multiforme of brain who received postoperative radiotherapy in the period between February 1979 and December 1985. Fourteen patients had grade I astrocytoma, 11 patients grade Ⅱ, 14 patients grade Ⅲ, and 10 patients glioblastoma multiforme. Three year actuarial survival rates were 85.7%, 44.6% and 23.1% for grade Ⅰ,Ⅱ, and Ⅲ astrocytomas, respectively. One and 2 year actuarial survival rates for patients with glioblastoma multiforme were 54.5% and 27.3%, respectively. Histologic grade, age, extent of operation and tumor location were revealed to be prognosticators.

Radiation Therapy Results of Invasive Cervical Carcinoma Found After Inappropriate Hysterectomy

최두호(Doo Ho Choi),김은석(Eun Seog Kim),남계현(Kae Hyun Nam),허승재(Seung Jae Huh) 대한방사선종양학회 1996 Radiation Oncology Journal Vol.14 No.3

목적 : 상피내암, 초기 침윤성 자궁경부암, 또는 양성 질환으로 자궁적출술 받은 후 침윤성 자궁경부암으로 확인되어 방사선치료를 받은 환자의 치료 결과와 예후를 분석 하고자 하였다. 대상 및 방법 : 1985년 9월부터 1993년 12월까지 수술후 침윤성 자궁암으로 진단되어 방사선치료를 시행한 61명의 환자를 대상으로 후향적 분석을 시행하였다. 수술전 진단은 상피내암이 가장 많았으며 (38명), 초기 침윤성 자궁암 (10명), 자궁근종 (6명)등이었다. 대부분 수술후 2개월 이내에 방사선치료를 시행하였으며 3명은 추적검사중 재발암으로 확인되어 치료하였다. 8명은 강내치료만을, 47명은 외부 방사선치료만을, 그리고 6명은 강내치료와 외부 방사선치료를 같이 시행하였다. 결과 : 5년 생존율 및 무병 생존율은 각각 83.8%, 86.9% 였으며 수술 당시의 육안적 잔존병소가 있었던 경우는 38.4%로 매우 낮았다. 모두 8명의 치료실패가 있었으며 예후인자로는 후향적 병기, 잔존병소 유무, 병리조직유형이 있었다. 결론 : 조기 침윤성 자궁암은 부적절한 수술후에도 방사선치료로 효과가 좋으나 잔존병소가 있는 경우에는 예후가 불량하므로 좀 더 적극적인 치료가 필요하며, 무엇보다도 조기에 정확한 검진과 병기 결정을 시행하여 각 병기에 따른 적절한 치료가 필요하다. Purpose : Hysterectomy without lymph node dissection was considered an inadequate treatment method for invasive uterine cervix cancer. Usually the procedure was performed inadvertently on patients who were thought to have benign or premalignant conditions preoperatively. We analysed radiotherapy results of such patients to evaluate survival rates, failure patterns and prognostic factors according to various conditions. Materials and Methods : Sixty one patients undergoing hysterectomy in the presence of invasive cervical carcinoma were reviewed retrospectively. Preoperative diagnosis were carcinoma in situ (38 cases), severe dysplasia (2), myoma (6), uterine bleeding (4), uterine prolapse (2). and early invasive cervix cancer (10) (One patient had myoma and carcinoma in situ coincidently). Patients received postoperative megavoltage radiotherapy from August 1985 to December 1993, and minimum follow-up period was 24 months. Eight patients received ICR only, 6 patients ICR and external radiation, and 47 patients received external radiation therapy only. Results : Overall 5-year survival rate and relapse-free survival rate werer 83.8%, 86.9% respectively. For patients with retrospective stage IA, IB, IIB (gross residual after surgery), and vaginal cuff recurrence were 90.9%, 88.8%, 38.4%, and 100% respectively There were 8 cases of treatment failure, most of them (5/8) were in patients with gross residual disease, other patients were full thickness involvement of cervix wall (2/8) except one. Patients with early vaginal cuff recurrence and microinvasive cervical cancer (stage IA) had no treatment related failure Prognostic factors affecting survival by univariate analysis were status of residual disease, tumor histology and retrospective stage. Conclusion : Adjuvant radiotherapy appeared to be effective treatment method for patients with presumed stage IA, IB and early local recurrent disease after inadvertent hysterectomy Survivals for patients with gross disease remained after inappropriate hysterectomy was poor, So, early cancer detection and Proper management with precise pretreatment s1aging is necessary to avoid inadherent hysterectomy especially in the cases of gross residual disease.