근원 불명 전이암의 예후인자와 생존율

원종호,박성규,홍대식,박희숙,김은석,최두호 순천향의학연구소 1999 Journal of Soonchunhyang Medical Science Vol.5 No.1

Purpose : Patients with cancer of unknown primary site represent 5% to 10% of all cancer patients. This study was to evaluate survival and prognostic factors of patients with malignancy of unknown origin. Materials and Methods : A retrospective analysis was done for one hundred and two patients with malignancy of unknown origin who were treated from January 1989 to December 1998. There were 52 male and 50 female patients. Age of patients ranged from 20 to 94 years (mean 58 years). Clinical presentation depended on the site of metastases. In cases of multiple metastatic sites, we selected the first apparent metastasis or the symptomatic one for which the patient was first seen. The three most frequent initial metastatic sites were peritoneum, lymph node, and liver. Median follow up period was 4 months(0-100 months) and survival rate measured form the time of diagnosis. Results : The two years survival rate was 13.6% with a median survival time of 4 months. The factors associated with the overall survival rate were the tumor marker CEA(p=0.0061), smoking history(p=0.0039), and histologic type(squamous cell carcinoma versus non-squamous cell carcinoma, p=0.0295). Marginal statistical difference was found according to performance status. No statistical differences were found according to sex, weight loss, initial metastatic site and numbers, primary lesion site, and treatment modality. Conclusion : Squamous cell carcinoma was associated with survival rate. In squamous cell carcinoma of unknown origin with good prognostic factor, especially cervical lymph node metastasis, we suggest an approach of extensive initial workup for staging and aggressive treatment.

推論과 證明指導에 관한 考察

김종구,임석훈,설영수 경북대학교 과학교육연구소 1997 科學敎育硏究誌 Vol.21 No.-

This study is to discuss the educational problem about whether an exact proof is useful in the secondary school mathematics education formally in the development of mathematical thought and whether we should teach students an exact proof up to an extent.

퍼지 패턴인식법을 이용한 발전소 과도상태 판별

김종석,이동주 한국공작기계학회 2005 한국생산제조학회지 Vol.14 No.1

Plant pipe has a fatigue life which is induced by repeated stress come from the variation of temperature and pressure. To avoid the fatigue crack of plant pipe which is produced by long term repeated stress, plant operator has to limit the amount of operating transient. This paper introduced the study result about discrimination methodology of plant transient by using the fuzzy pattern recognition. As result of applying the fuzzy pattern recognition to actual plant operation data, it is confirmed that fuzzy pattern recognition methodology can be useful for the comparison of similarity for the transients of similar output but has different time pattern.

한반도 동부회랑의 경쟁력 강화방안

한종길,하영석 한국해운물류학회 2003 해운물류:이론과실천 Vol.- No.6

본 연구는 물류 회랑 정비는 지역 경제권의 형성 및 발전의 전제 조건이며 동북 아시아 지역에서 환동해경제권이나 동북아 공동시장과 같은 지역 경제권의 형성을 위해서는 회랑 정비가 우선되어야 한다는 관점에서 접근하고 있다. 또, 동북아 물류중심국가 논의에 부응하는 실천 수단의 하나로써 동해항의 발전을 위해서는 한반도 동부 회량의 정비가 중요한 과제 중의 하나라는 점이 본 연구의 중요한 관점이다. 이를 위해 본 연구에서는 먼저 경제권 형성과 물류 회랑 논의에 대하여 선진 사례라고 할 수 있는 유럽의 사례를 개괄하고, 일본의 ERINA에서 제안한 동북아 물류 회랑의 개요를 고찰하였으며 마지막으로 동북아 물류 회랑과 한반도 동부 회랑의 경쟁력 강화를 위한 동해항과 강원도 역할에 대하여 제시하였다. 한반도 동부 회랑의 경쟁력 강화를 위해서는 첫째로 시급한 인프라 정비, 두 번째로 해상 부문 네트워크와의 접속, 셋째로 가격 경쟁력의 확보를 위한 노력이 필요하다. 이를 위해 강원도와 동해항은 ①개발회랑 개념으로 정부의 정책적 지원을 요구. ②한반도 동부 회랑 사업에 대한 지속적 정보 전달이 필요하다. This paper focused on how to strengthen the competitiveness of Korean East transportation corridor (Busan~Donghae~Rajin Khasan~Ussuriysk~SLB) compare to nine transportation corridors in northeast Asia. Development of transportation corridor is one of the key issues for mutual cooperation and collaboration in the Northeast Asian Region. In order to increase the competitiveness of Korean East transportation corridor, we propose following 3 issues. 1) Develop key infrastructure urgently. 2) connecting network with ocean transport. 3) obtaining price competitiveness compare to other corridors. The roles of the local government in promoting development are 1) to obtain cooperation and financial assistance from national government with concept of development corridor. 2) to provide most up-to-date information about corridor to cargo owner, etc., for realizing the transportation routes in a practical way.

Cr첨가에 따른 자동차용 소결 밸브시트의 미세조직과 기계적 성질

具原奭,朴種寬,崔昌守,정인상 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.8

Valve seat inserts are used in the valve train area of internal combustion engines. Good wear resistance is needed since repeated stress is applied by the valves under combustion gas atmosphere of high temperatures. Currently, most of the valve seat inserts are being manufactured by P/M route. In this study, the characteristics of materials especially the wear resistance with the addition of Cr-hard particles were investigated. The results of this study are as follows: increase in the Cr-hard particles resulted in a decrease of the density of specimens. Pores formed by Cr diffusion from Cr-hard particles was attributed to the reduction in density. As a result, radial crushing strength was decreased with increase of the Cr-hard particals. Engine simulation test indicated that matrix can be hardened with the addition of Cr-hard particles. The excess addition of Cr-hard particles, however, degrades the wear resistance by the increase of residual pores. Therefore, the appropriate amount of Fe-Cr-C hard particles is 1∼5 wt%.

S. cerevisiae와 A. pullulans를 이용한 중금속 제거에 있어 중금속의 선택도에 관한 연구

김동석,서정호,이종헌,송승구 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.6 No.1

폐수중에 함유한 중금속을 처리하기 위하여 미생물을 이용한 중금속 제거공정의 응용가능성을 알아보고자 하였다. Cd, Cr, Ni, Pb을 사용하여 균류인 S. cerevisiae와 A. pullulans의 각 단일 중금속에 대한 제거 선택도와 혼합 중금속의 제거 선택도를 관찰하였고, Pb에 대한 2가지 미생물의 제거특성을 고찰함으로써 각 제거기작에 대한 기초연구를 하였다. 1) S. cerevisiae와 A. pullulans에 대한 단일 중금속(Cd, Cr, Ni, Pb)의 선택도는 다음과 같다 Pb>Cr>Ni>Cd (S. cerevisiae) Pb>Cr>Cd>Ni (A. pullulans) 2) S. cerevisiae와 A. pullulans에 대한 혼합 중금속(Cd, Cr, Ni, Pb)의 선택도는 다음과 같다. Pb>Cr>Ni>Cd (S. cerevisiae) Pb>Cr>Ni>Cd (A. pullulans) 3) 본 실험에서의 선택 순서는 중금속의 원자반경의 크기에 따라 나타났다. 4) S. cerevisiae의 Pb 제거 특성에 있어 초기 PB의 농도가 증가할수록 단위 미생물당 중금속 제거량은 증가하였으며 평형에 도달하는 시간도 증가하는 것으로 나타나, Pb의 세포내 침투가 발생함을 간접적으로 알 수 있었다. 5) A. pullulans는 Pb의 제거에 있어 S. cerevisiae와 마찬가지로 초기 Pb의 농도가 증가할수록 단위 미생물당 중금속 제거량은 증가하였으나, 평형에 도달하는 시간은 초기 Pb의 농도에 거의 무관하였다. 그러므로 A. pullulans의 Ph 제거기작에서는 Pb의 세포내 침투가 발생하지 않음을 간접적으로 알 수 있었다. 6) 2종류 미생물의 PB에 대한 제거능을 비교해보면 초기 Pb의 농도가 96 mg/l 정도인 경우에 A. pullulans에서는 단위 미생물당 흡착량이 120 mg Pb^2+/g로 나타났으나, S. cerevisiae의 경우에서는 70 mg Pb^2+/g로 나타나, 미생물을 이용한 중금속 제거공정을 실용화하고자 할 경우에는 A. pullulans가 보다 유리할 것으로 판단되었다. Waste heavy metals which have a reputation of detrimental effect on the environment through the food chain are generated from mining, dyestuff, material, electric, and petroleum industries. In this study, the feasibility a heavy metal removal process using microorganisms which is an alternative method to remove and recover heavy metals was examined, in order to treat the heavy metal in waste water. The removal selectivity about single and mixed heavy metals(Cd, Cr, Ni, Pb) using Saccharomyces cerevisiae and Aureobasidium pullulans, and the effect of initial heavy metal concentration on the removal of heavy metal were determined. The order of selectivity were Pb〉Cr〉Ni〉Cd(S. cerevisiae) and Pb〉Cr〉Cd〉Ni(A. pullulans) in single metal solution and Pb〉Cr〉Ni〉Cd(S. cerevisiae and A. pullulans) in mixed metal solution. The order of selectivity was mainly depended on the ionic radius. The amounts of heavy metal removal and the time required to the equilibrium state were increased according to the increase of initial heavy metal concentration in S. cerevisiae, but the time to reach equilibrium state was independent of initial concentration in the case of A. pullulans. These facts show that the penetration of heavy metal into the inner cellular part was occured in S. cerevisiae and it cannot be done in A. pullulans.

강유전성 BaTiO₃의 분극처리에 의한 유사체액 내에서 Calcium Phosphate 생성

송종은,김은주,황규석,임용무,박영준 대한치과기재학회 2000 대한치과재료학회지 Vol.27 No.4

Barium titanate (BaTiO3; BTO) has wide application in industry, particularly in the manufacturing of dynamic random access memory chips, electro-optical switches, optical modulators, shutters, optical mixers, and sensors, owing to its ferroelectric and piezoelectric properties after poling treatment. There has recently been considerable interest in the properties of its role in osseointegration. In this study, we investigated the possibility of treating BTO by poling to improve osseointegration by examining the calcium phosphate (Ca-P) crystal growth behavior on the poled and non-poled BTO surfaces in simulated body fluids (SBF). The BTO samples were sintered at 1350℃ for 2 h in air, producing an average grain size of 7 ㎛, which were confirmed by SEM observation. The sintered BTO samples were then polarized (Ep=5 kV/cm) from 160℃ to 25℃ in a Si oil bath for 2 h. The poled and non-poled BTO samples were immersed in 1.5 SBF for 15 days, or 30 days at 37℃. After the immersion period, the morphological and compositional changes of the surface of the immersed BTO specimens were investigated using a field emission scanning electron microscope (FE-SEM) and an energy dispersive X-ray spectrometer (EDX). Qualitative analysis was then performed using fourier transform infrared (FTIR) analysis. Weak and coarse Ca-P crystals had grown on the surface of the non poled BTO, while a marked difference in the Ca-P forming pattern was visible for the poled BTO, showing the negatively charged surface induces a Ca-P layer more easily. We assumed that rapidly adsorbed cations (Ca2+ ions) on the negatively charged surface at the initial stage acted as nuclei for the formation of Ca-P crystals, while no nuclei would be available on the positively charged surface, due to the fact that sodium chloride (NaCl) crystals were formed owing to anion adsorption (Cl ions). In summary, these results demonstrate that poling the ferroelectric BTO surface negatively the possibility of implant osseointegration.

활성탄소천 전극을 이용한 NaCl과 NaF 용액에서 축전식 이온제거

이광석,김종환,김진환 한국공업화학회 2003 응용화학 Vol.7 No.1

Electrosorption is defined as potential-induced adsorption on the surface of charged electrodes. After polarization of the electrodes, ions are removed from the electrolyte solution by the imposed electric field and held in electric double layers formed at the surface of electrodes. Unlike ion exchange, no chemicals are required for regeneration of the system, hence no secondary waste is generated. In this study, experimental electrosorption of ions from aqueous NaCI and NaF solutions were conducted using activated carbon cloth electrodes and the effects of distance between electrodes, applied voltage and electrolyte concentration on the electrosorption capacity have been investigated.

신손상 환자의 치료에 따른 임상적 고찰

윤종선,소영석,안병수,노준,박도영 조선의대 1995 The Medical Journal of Chosun University Vol.20 No.2

각종 치과레이저의 Streptococcus mutans에 대한 증식 기능억제 효과

한강석,국중기,유소영,김화숙,박종휘,박현동,이상훈 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.3

레이저의 구강내 산 생성 세균인 S. mutans에 대한 증식 및 기능 억제효과를 평가하기 위하여 S. mutans KCTC 3065가 포함된 세균 pellet에 Er:YAG 레이저와 Nd:YAG 레이저를 비접촉식 방법으로, 조사세기 50mJ, 조사시간 5초, 그리고 pulse repetition rate를 각각 10Hz와 30Hz로 하여 조사하고 세균 군락수, 산 생성능, 불용성 세포외다당류의 합성량을 측정하여 다음과 같은 결과를 얻었다. 1. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 S. mutans의 증식을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 증식을 억제하였다. Chinese ink를 사용하지 않고 ND:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 증식을 억제하지 못하였다. 2. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 일정기간 동안 S. mutans의 산생성능을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 산 생성능을 억제하였다. Chinese ink를 사용하지 않고 Nd:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 산 생성능을 억제하지 못하였다. Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우는 pulse repetition rate가 클수록 전반적으로 세균의 산생성능을 더 많이 억제하였다. 3. 레이저 조사는 S. mutans의 불용성 세포외다당류의 합성에 영향을 미치지 못하였다. 이상의 결과로 보아 Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후의 Nd:YAG 레이저 조사는 일정시간 동안 S. mutans의 증식과 산 생성능을 억제시키므로써 치아우식증 예방효과를 얻을 수 있다고 사료되나 억제효과가 오래가지 않아 임상적으로 효과를 얻기 위해서는 자주 조사를 해주어야 한다는 문제점을 안고 있어 임상적으로 치아우식증 예방이란 단독 목적으로 사용하기에는 실용성이 크지 않다고 사료된다. This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd:YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiatioin of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prenent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.