쑥갓세포의 현탁배양에 의한 ${\beta}-sitosterol$ 생산

김현철,정하영,이소연,정호용,김유정,백남인,김성훈,최근원,김대근,권병목,박미현,정인식,Kim, Hyun-Chul,Chung, Ha-Young,Lee, So-Youn,Chung, Ho-Yong,Kim, You-Jung,Baek, Nam-In,Kim, Soung-Hoon,Choi, Geun-Won,Kim, Dae-Keun,Kwon, Byoung-Mok,Park 한국응용생명화학회 2005 Applied Biological Chemistry (Appl Biol Chem) Vol.48 No.4

[${\beta}-sitosterol$]은 식물 스테롤로서 인간의 전립선암과 대장암 세포의 성장을 억제하고 생체내 콜레스테롤 농도를 감소시킨다. 본 연구에서는 쑥갓세포 배양에서 ${\beta}-sitosterol$ 생산의 최적화 연구를 수행하였다. 그래서 쑥갓(Chrysanthemum coronarium L.)으로부터 캘러스 유도는 NAA와 BAP의 농도가 각각 1 mg/l의 조합에서 최적이었으며 이들 캘러스로부터 현탁배양 세포주를 확립하였다. 현탁 배양시 초기 세포농도 2 g DCW/l에서 조성이 각각 1배인 탄소원(30 mg/l), 질소원(1900 mg/l $KNO_3$, 1650mg/l $NH_4NO_3$), 무기인산원(170 mg/l)을 포함하는 MS 배지에서 ${\beta}-sitosterol$ 생산이 최적으로 나타났다. Shake-flask를 이용한 현탁배양에서 ${\beta}-sitosterol$의 최대 생산량은 $150{\mu}g/g$ DCW이었다. 그리고 공기부유식 생물반응기의 배양에서는 100 cc/ml의 통기량에서 ${\beta}-sitosterol$의 생산이 $142.8{\mu}g/g$ DCW으로 나타났다. [${\beta}-sitosterol$] is a plant sterol that reduces cholesterol levels and inhibits the growth of human prostate and colon cancer cells. Optimal conditions for ${\beta}-sitosterol$ production were examined from cell suspension cultures of Chrysanthemum coronarium L. The callus induction was optimal in MS medium containing 1 mg/l NAA and 1 mg/l BAP. Cell suspension culture was also established from the callus. Optimal ${\beta}-sitosterol$ production was obtained when the cells were cultured at an initial density of 2 mg DCW/l in MS medium containing 1 X sucrose (30 mg/l), 1 X nitrogen (1900 mg/l $KNO_3$, 1650 mg/l $NH_4NO_3$), and 1 X phosphate source (170 mg/l). In cell suspension cultures of C. coronarium L. using shake flasks, the peak content of ${\beta}-sitosterol$ was $150{\mu}g/g$ DCW. In cell suspension cultures of C. coronarium L. using an air-lift bioreactor, the maximum ${\beta}-sitosterol$ content of $143.8{\mu}g/g$ DCW was obtained at an air-flow rate of 100 cc/min.

우리나라 중고등학교 청소년의 성별 및 학교 종류별 흡연 결정요인

김현철,김은경,최은실,김유정,이현주,김정주,장형숙,심경선,전상남,강요한,강현석,오주환,조경숙,Kim, Hyun-Cheol,Kim, Eun-Kyong,Choi, Eun-Sil,Kim, Yu-Jeong,Lee, Hyun-Ju,Kim, Jong-Ju,Jang, Hyung-Suk,Shim, Kyung-Seon,Jeon, Sang-Nam,Kang, Yo-Han,Ka 대한예방의학회 2006 예방의학회지 Vol.39 No.5

Objectives: This study assessed the influences of various factors that are related to youth smoking such as gender, age and type of school, and we wanted to provide supporting data for tailored and effective policy initiatives to reduce adolescent smoking. Methods: A self-report survey was conducted on 14,910 teen-age students who were selected based on the nationwide distribution of students in large and small cities and counties, the gender ratio of the students and the ratio of students attending various type of school at 38 middle and high schools in six representative areas of each province. The survey was handled and managed by a health education teacher at each school. Binary and multinomial logistic regression was used in the analyses. Results: Smoking by adolescents was associated with gender, age and even height. Male high school students tended to smoke more than female high school students, but this differences was not significant for middle school students. The older the adolescents were, the more likely that they smoked, except for the female high school students. Height was meaningful for all adolescents, except for the boys at the vocational high schools. Monthly allowance was significant for all adolescents. School factors such as type of school and the students' school performance were also crucial factors. Attending a vocational high school was strongly related to smoking, especially for girls. Students' school performance and the perceived level of stress were strongly associated with smoking, especially for boys. Home factors such as the relationship with parents and conversation time with family members were closely related to smoking behavior. Knowledge about the health hazard of smoking was also found to be strongly related to adolescent smoking. Conclusions: In conclusion, demographic factors, school factors, home surroundings and the perception on the harmfulness of smoking are strongly related to adolescent smoking behavior, but these differ from gender and type of school.

Aging Study with High-Level Radiation Sources for the CMS Forward RPCs

김현철,이경세,Byun Il Kim,홍병식,Chong Kim,D. H. Moon,Duk Gil Koo,E. Won,J. K. Lim,Ji Hyun Kim,Jun Tak Rhee,K. B. Lee,Kwang-Souk Sim,M. S. Ryu,Rong Jiang Hu,S. K. Nam,Sang Yeol Bahk,이석재,Seong Jong Hong,Sung Hw 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.3

An aging study with intensive radiation sources was performed for the forward resistive plate chambers (RPCs) of the Compact Muon Solenoid (CMS) detector in the Large Hadron Collider experiment (LHC). The expected rate of the radiation background to be induced in the forward RPCs ranges from a few tens of Hz/㎠ to as much as ~1 kHz/㎠. Therefore, the radiation hardness for the forward RPCs should be sufficient to ensure the safe operation of the CMS and successful achievement of the LHC physics. Two oil-coated and one plain double-gap RPCs were manufactured and tested with the neutron beam provided by the MC50 cyclotron of the Korea Institute of Radiological and Medical Science (KIRAMS) and with gamma rays from a 200-mCi137Cs source. The estimated radiation dose induced by the fast neutrons was approximately 50 Gy. No significant aging effect was found to be a consequence of the neutron irradiation, However, a degradation of the RPC performance was observed after intense gamma irradiation for a total of 32.5 days. The mean gamma-signal rate drawn in each RPC was 4.0 kHz/㎠, which was approximately two times the maximum rate expected in the highest η-region covering the particle trigger. Increases in the noise rates and the currents accounted for the degradation in the efficiencies for the RPCs. As a result, safe operation of the forward RPCs in the avalanche mode was ensured for signal rates up to 2 kHz/㎠.

악성 흑색종과 멜라닌 세포성 모반의 bc1 - 2 단백의 발현 양상

김현철,김윤규,채영수,서기석,김상태 ( Hyun Cheol Kim,Yun Kyew Kim,Young Soo Chae,Kee Suck Suh,Sang Tae Kim ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.2

Background; The bcl-2 is a newly known oncogene involved in tumorigenisis by blocking apoptosis or programmed cell death. Overexpression of bcl-2 protein has been detected in a variety of human malignancies. However, recent studies of the expression of bcl-2 protein in human melanoma and melanocytic nevus have been controversial. Objective : The purpose of this study was to examine whether there are any differences in the expression of bcl-2 protein between melanocytic nevus and rnalignant melanoma. Methods : Immunohistochemical analysis of bcl-2 protein expression was performed on the formalin-fixed, paraffin-embedded tissue sections of 22 melanocytic nevus and 29 malignant melanomas(20 primary and 9 metastatic) using anti bcl-2 monoclonal antibody with an avidin-biotin peroxidase complex procedure. Results : The results were as follows. 1. The positive rate for bcl-2 protein was observed in 95.4% (21/22) of melanocytic nevus and 95.0%(19/20) of primary malignant melanomas. Therefore, there was no significant difference between the two groups in the positive rate for bcl-2 prtoein. 2. The percentage of stained cells and the staining intensity of bcl-2 protein were significantly increased in melanocytic nevus compared to malignant melanoma(p<0.05). 3. The positive rate for bcl-2 expression of metastatic malignant melanoma[44.4% (4/9)] was significantly decreased compared to that of primary malignant melanoma[95.0%(19/20) ](p<0. 05). But, there was no significant difference betweeen tumor thickness and histological type of malignant, melanoma in the expression of bcl-2 protein. 4. In melanocytic nevus, immunoreactivity of bcl-2 protein gradually diminished or even disappeared towards the deep dermis Conclusion : the bcl-2 expression was decreased in malignant melanoma compared to melanocytic nevus. It. suggests that the loss of bcl-2 expression may play a significant role in the progression and metastasis of malignant melanoma. (Kor J Dermatol 1997;35(2): 284-291)

스몰오버랩 충돌 시 하지상해 발생 메커니즘 규명

김현철,남윤식,김병철,김기일,김기성,Kim, Hyun Chul,Nam, Yun Sik,Kim, Byoung Chul,Kim, Ki Il,Kim, Ki Sung 한국자동차안전학회 2017 자동차안전학회지 Vol.9 No.1

Small Overlap test decided on IIHS (Insurance Institute for Highway Safety) evaluates a robustness of the car body and a passenger injury protection. A current vehicle is satisfied with a robustness of the car body for Small Overlap test but not meet the requirements of passenger injuries because it is difficult to inquire into the actual state of injury mechanism for Small Overlap test. The study shows the new injury mechanism which represents the relation between a structure of the vehicle placed with the lift foot and the low extremity injury.

점막하 구개열 환자 공명장애의 스펙트럼 특성 연구

김현철,임대호,백진아,신효근,김오환,김현기,Kim, Hyun-Chul,Leem, Dae-Ho,Baek, Jin-A,Shin, Hyo-Keun,Kim, Oh-Hwan,Kim, Hyun-Ki 대한악안면성형재건외과학회 2006 Maxillofacial Plastic Reconstructive Surgery Vol.28 No.4

Submucosal type cleft palate is subdivision of the cleft palate. It is very difficult to find submucosal cleft, because when we exam submucosal type cleft palate patients, it seems to be normal. But in fact, there are abnormal union of palatal muscles of submucosal type cleft palate patients. Because of late detection, the treatment - for example, the operation or the speech therapy - for the submucosal type cleft palate patient usually becomes late. Some patients visited our hospital due to speech disorder nevertheless normal intraoral appearance. After precise intraoral examination, we found out submucosal cleft palate. We evaluated the speech before and after surgery of these patients. In this study, we want to find the objective characteristics of submucosal type cleft palate patients, comparing with the normal and the complete cleft palate patients. Experimental groups were 10 submucosal type cleft palate patients and 10 complete cleft palate patients who got the operation in our hospital. And, the controls were 10 normal person. The sentence patterns using in this study were simple 5 vowels. Using CSL program we evaluated the Formant, Bandwidth. We analized the spectral characteristics of speech signals of 3 groups, before and after the operation. In most cases, the formant scores were higher in experimental groups (complete cleft palate group and submucosal type cleft palate group) than controls. There were small differences when speeching /a/, /i/, /e/ between experimental groups and control groups, large differences when speeching /o/, /u/. After surgery the formant scores were decreased in experimental groups (complete cleft palate group and submucosal type cleft palate group). In bandwidth scores, there were no significant differences between experimental groups and controls.

이미지 딥러닝을 통한 컨텐츠와 관련 반응 동영상의 감정 분석 시스템 설계

정윤영(Yoonyoung Jeong),김봄(Bom Kim),류소정(Sojeong Ryu),권나현(Nahyun Kwon),손규진(Gyujin Son),이소정(Sojeong Lee),김윤희(Yoonhee Kim) 한국정보과학회 2019 한국정보과학회 학술발표논문집 Vol.2019 No.12

중앙 큐 기반의 루프 스케쥴링 기법의 설계 및 구현

김현철,김효철,유기영,Kim, Hyun-Chul,Kim, Hyo-Cheol,Yoo, Kee-Young 대한전자공학회 2001 電子工學會論文誌-CI (Computer and Information) Vol.38 No.5

본 논문에서는 루프의 반복들간에 종속 관계가 존재하는 루프의 효율적 수행을 위한 중앙 큐 기반의 새로운 할당 기법 CDSS(Carreid-Dependence Self Scheduling)를 제안하며, 이를 공유 메모리 환경에서 Java 언어로 구현하였다. 또한, 중앙 작업 큐 기반의 병렬 루프를 위한 셀프 스케쥴링(self-scheduling) 기법들을 루프 캐리 종속성(loop-carried dependence)을 가진 루프의 할당에 적용하기 위한 그들의 변형에 대해 알아본다. 제안된 기법은 종속 거리에 따른 동기화 시점을 고려하여 루프를 세 단계별로 할당하는 셀프 스케쥴링 기법이다. 단일처리기 시스템을 포함한 여러 플랫폼에 적용하기 위해 제안된 방법과 변형된 기법들을 스레드 레벨로 구현하였다. 응용 프로그램과 시스템 파라메터 값을 다양하게 하여 변형된 기법들과 비교 분석한 결과, 제안된 기법은 변형된 다른 기법들에 비해 스케쥴링 오버헤드를 포함한 전체 루프의 수행 시간을 줄여 효율적이다. 변형된 SS, Factoring, GSS, CSS에 대해 각각 0.02, 40.5, 46.1, 53.6%의 성능 향상을 보였다. 그리고, CDSS 기법으로 다양한 응용 프로그램에 대해 종속 거리에 해당하는 적은 수의 스레드를 사용하여 최대의 성능을 얻을 수 있다. In this paper, we present a new scheduling method called CDSS(Carried-Dependence Self-Scheduling) for efficiently execution of the loop with intra dependency between iterations based on the central queue. We also implemented it on shared memory system using Java language. Also, we study the modification that converts the existing self-scheduling method based on the central task queue for parallel loops onto the same form applied to loop with loop-carried dependences. The proposed method is self scheduling and assigns the loops in three-level considering the synchronization point according to the dependence distance of the loops. To adapt the proposed scheme and modified methods into various platforms, including a uni-processor system, we use threads for implementation. Compared to other assignment algorithms with various changes of application and system parameters, CDSS is found to be more efficient than other methods in overall execution time including scheduling overheads. CDSS shows improved performance over modified SS, Factoring, GSS and CSS by about 0.02, 40.5, 46.1 and 53.6%, respectively. In CDSS, we achieve the best performance on varying application programs using a few threads, which equal the dependence distance.

양자암호 통신망에서 양자키 관리를 위한 통합 데이터 구조

김현철,Kim, Hyuncheol 한국융합보안학회 2021 융합보안 논문지 Vol.21 No.1

양자 역학을 기반으로 하는 양자암호통신에서는 각각의 정보를 개별적인 광자에 실어 전송하기 때문에 일부만 도청하는 것이 기본적으로 불가능하며, 침입자가 광자를 불법적으로 가로채 수신자에게 재전송을 하여도 양자 복제 불가능성 원리에 의해 같은 정보를 광자에 실어 보내는 것이 불가능하다. 한편 네트워크 기반 다양한 서비스의 폭발적 증대와 함께 해당 서비스의 보안성 보장이 필수적으로 요구되면서 양자암호 통신망의 구축 및 관련 서비스가 다양한 형태로 추진되고 있다. 그러나 양자키 분배(QKD: Quantum Key Distribution) 기술의 발전과는 별개로 이를 활용한 네트워크 구축 및 다양한 양자암호 기반 서비스 제공 방안에 관해서는 많은 연구가 필요한 상태이다. 본 논문에서는 양자암호 장치를 기반으로, 다양한 양자암호 통신망 장비 간에 양자키를 전달하고 암호화된 전송환경 구현을 위한 통합 데이터 구조를 제안하였다. In quantum cryptographic communication based on quantum mechanics, each piece of information is loaded onto individual photons and transmitted. Therefore, it is impossible to eavesdrop on only a part, and even if an intruder illegally intercepts a photon and retransmits it to the recipient, it is impossible to send the same information to the photon by the principle of quantum duplication impossible. With the explosive increase of various network-based services, the security of the service is required to be guaranteed, and the establishment of a quantum cryptographic communication network and related services are being promoted in various forms. However, apart from the development of Quantum Key Distribution (QKD) technology, a lot of research is needed on how to provide network-level services using this. In this paper, based on the quantum encryption device, we propose an integrated data structure for transferring quantum keys between various quantum encryption communication network devices and realizing an encrypted transmission environment.

법학자 입장에서 보는 생명윤리

김현철,Kim, Hyeon-Cheol 한국과학기술단체총연합회 2006 과학과 기술 Vol.39 No.2