Raw 264.7 세포에서 유해산소 생성에 미치는 Caffeic Acid의 영향

최병철,Choi, Byung-Chul 대한약학회 2008 약학회지 Vol.52 No.6

To investigate effect of caffeic acid on the intracellular reactive oxygen species production, we used DHE for intracellular superoxide anion production, DCF for intracellular ${H_2}{O_2}$ production and DHR for intracellular hydroperoxide production in Raw 264.7 cells. DPPH assay showed that antioxidant activity of caffeic acid with 39.5 ${\mu}M$ of ${IC}_{50}$ values was similar to that of ascorbic acid with 41.3 ${\mu}M$ of ${IC}_{50}$ values. Caffeic acid dose-dependently inhibited silica-induced ${H_2}{O_2}$ and hydroperoxide production but did not affect superoxide anion production in Raw 264.7 cells, which suggest that antioxidant effect of caffeic acid acts on the post-step of superoxide anion. On the other hand, caffeic acid showed a potent antioxidant effect in $lCuSO_4$-induced lipid peroxidation. Furthermore, plasma superoxide dismutase activity (3.43${\pm}$0.23 U/ml) in 10 mg/kg caffeic acid-fed mice was significantly higher than that (2.32${\pm}$0.24 U/ml) of control. From the above results, it is referred that caffeic acid appears to have potent anti-oxidant activity in both cell system and in vivo system.

한 블록 당 실험의 크기가 2인 경우 정의대비를 이용한 2ⁿ요인실험과 그 일부실시법의 설계방법

최병철,Choi, Byoung-Chul 한국통계학회 2008 Communications for statistical applications and me Vol.15 No.4

동일 환경에서 할 수 있는 실험의 크기가 2인 경우 $2^n$요인실험과 그 일부실시법을 설계하려면 교락법을 반복적으로 사용해야한다. $2^n$요인실험 또는 그 일부실시법의 교락법들을 적절히 조합하면 모든 주효과와 2인자 교호작용효과 전부 또는 일부를 검출할 수 있는 실험을 설계할 수 있다. 이런 실험을 설계하기 위해 정의대비를 이용했고 설계된 실험의 처리조합을 제시하였다. Confounding techniques have to be used repeatedly in the situations where it is necessary to perform only 2 runs under homogeneous conditions in $2^m$ factorial and fractional factorial experiment. Combinations of confounded $2^m$ factorial and fractional factorial designs enable the estimation of all main effects and all of or a part of 2 factor interaction effects. Defining contrast are used for our designs and treatment combinations of designs to be run are presented.

심활성도 압반사 제어 모델을 이용한 심혈관시스템 모델링 및 시뮬레이션

최병철,정도운,손정만,예수영,김호종,이현철,김윤진,정동근,이상훈,전계록,Choi Byeong Cheol,Jeong Do Un,Shon Jung Man,Yae Su Yung,Kim Ho Jong,Lee Hyun Cheol,Kim Yun Jin,Jung Dong keun,Yi Sang Hun,Jeon Gye Rok 대한의용생체공학회 2004 의공학회지 Vol.25 No.6

본 연구에서는 심혈관시스템 내의 압력 변화를 감지하는 압수용체 중 가장 대표적인 대동맥 압수용체의 시뮬레이션을 위한 심활성도 압반사 제어모델을 제안하였다. 그리고 제안된 모델은 압반사 조절, 시간지연을 포함한 전기회로 모델들로 구성하였으며, 대동맥동의 압반사 조절시 시간지연이 심주기와 일회 심박출량에 주는 영향을 관찰할 수 있도록 하였다. 심활성도 압수용체 제어 모델에서 시간지연의 기전은 대동맥동 압수용체에서 감지된 압력 정보가 구심성 신경으로 전달되고, 이 정보는 중추신경을 거쳐 원심성 신경으로 전달되어 제어 기능을 수행한다. 제안된 모델의 시뮬레이션 결과 시간지연에 따라 심혈관시스템 변이성의 세가지 패턴을 관찰할 수 있었다. 먼저 시간지연이 2.5초 이상일 경우에는 대동맥압, 일회심박출량, 심박동수가 비주기적으로 발생하고 불규칙인 것을 관찰할 수 있었고, 시간지연이 0.1초에서 2.5초 사이일 경우에는 주기적인 진동이 발생함을 관찰할 수 있었다. 그리고 시간지연이 0.1초 이하인 경우에는 심박동수와 동맥압-심박동수의 궤적은 안정상태를 유지함을 관찰할 수 있었다. In this paper, we proposed a heart activity control model for simulation of the aortic sinus baroreceptor, which was the most representative baroreceptor sensing the variance of pressure in the cardiovascular system. And then, the heart activity control model composed electric circuit model of the cardiovascular system with baroreflex control and time delay sub-model to observe the effect of time delay in heart period and stroke volume under the regulation of baroreflex in the aortic sinus. The mechanism of time delay in the heart activity baroreflex control model is as follows. A control function is conduct sensing pressure information in the aortic sinus baroreceptor to transmit the efferent nerve through central nervous system. As simulation results of the proposed model, we observed three patterns of the cardiovascular system variability by the time delay. First of all, if the time delay over 2.5 second, aortic pressure and stroke volume and heart rate was observed non-periodically and irregularly. However, if the time delay from 0.1 second to 0.25 second, the regular oscillation was observed. And then, if time delay under 0.1 second, then heart rate and aortic pressure-heart rate trajectory were maintained in stable state.

황사의 발생 및 예보

최병철,Choi Byeong-Cheol 대한설비공학회 2006 설비저널 Vol.35 No.4

스퍼터링 타겟용 저온 분사 Cu-15 at.%Ga 코팅 소재의 특성에 미치는 열처리 분위기의 영향

최병철,박동용,김형준,오익현,이기안,Choi, Byung-Chul,Park, Dong-Yong,Kim, Hyung-Jun,Oh, Ik-Hyun,Lee, Kee-Ahn 한국분말야금학회 2011 한국분말재료학회지 (KPMI) Vol.18 No.6

This study attempted to manufacture a Cu-15 at.%Ga coating layer via the cold spray process and investigated the effect of heat treatment environment on the properties of cold sprayed coating material. Three kinds of heat treatment environments, $5%H_2$+argon, pure argon, and vacuum were used in this study. Annealing treatments were conducted at $200{\sim}800^{\circ}C$/1 hr. With the cold sprayed coating layer, pure ${\alpha}$-Cu and small amounts of $Ga_2O_3$ were detected in the XRD, EDS, EPMA analyses. Porosity significantly decreased and hardness also decreased with increasing annealing temperature. The inhomogeneous dendritic microstructure of cold sprayed coating material changed to the homogeneous and dense one (microstructural evolution) with annealing heat treatment. Oxides near the interface of particles could be reduced by heat treatment especially in vacuum and argon environments. Vacuum environment during heat treatment was suggested to be most effective one to improve the densification and purification properties of cold sprayed Cu-15 at.%Ga coating material.

u-IT 기술혁신과 산업변화

최병철,박기식,Choi, B.C.,Park, K.S. 한국전자통신연구원 2006 전자통신동향분석 Vol.21 No.2

최근 컨버전스가 하나의 트렌드로 정착해 감에 따라, 그 동안 기기 및 기능 중심으로진행되던 디지털컨버전스가 이제는 인간, 사물, 공간을 유기적으로 통합하는 차원에서인간과 사물, 그리고 공간과 IT가 한데 어우러지는 유비쿼터스 양상으로까지 발전하고있다. 유비쿼터스 컴퓨팅 기술의 발달과 더불어 이제 유비쿼터스는 단순한 개념정립단계를 넘어 u-City, u-Health, u-교통, u-교육, u-유통/물류 등 수많은 분야에서 현실에 접목되면서 점점 더 구체화되고 있다. 유비쿼터스 기술이 가져오게 될 소위 유비쿼터스 IT 혁명은 소리없이 우리에게 다가오고 있으나, 그것이 몰고 올 변화는 우리 생활양식의 변화를 포함하여 실로 막대할 것으로 예측되고 있다. 이에 본 고에서는 u-IT시대를 향한 기술발전의 방향과 함께 그에 따른 관련 산업의 변화되는 모습을 예측해보고, 나아가서는 u-IT 사회를 조기에 구현하기 위해 해결되어야 할 주요한 과제들은 무엇인지를 간단하게 살펴보고자 한다.

의약분업에 따른 약국 한약 활성화에 대한 조사 연구

최병철,김지인,손의동,Choi, Byung-Chul,Kim, Ji-In,Sohn, Uy-Dong 대한약학회 2008 약학회지 Vol.52 No.6

The purpose of this study is to investigate the best way that Oriental medicine contributes for activation of pharmacy management after the separation of prescribing and dispensing practice since July 2000. In order to investigate current pharmacy conditions for handling of Oriental medicine and many problems for administering the Oriental medicine to patients, a questionnaire was written with a list of questions related to pharmacy management with Oriental medicine, and given to 58 subjects via fax or personal visit during the period of April 21 to 30, 2003. The research results was as follows; In th 58 subjects, 45 subjects (77.6%) were pharmacists with a licence for dispensing Oriental medicine. 70.7% of subjects most likely preferred to extract granule as administering type of oriental medicine. About the motivation using Oriental medicine, the reason for activation of pharmacy management was 39.7%, second, the reason for resolving the limitation of treatment over western medicine was 25.9%. Oriental medicine for patients was mainly administered by recommendation with pharmacist (65.5%). In comparison with after and before the separation of prescribing and dispensing, 51.7% of subjects answered that sale volume was decreased after the separation. Concerning the ratio of total sales volume to Oriental medicine within 5 years, 50% of subjects expected that sales volume will increase positively. About treating Oriental medcine, 34.5% of subjects thought the problem is the regulation by limiting 100 kinds of formulary. The most important factor for increasing Oriental medicine selling amount was continueous education for various information of oriental medicine in case of 44.8% of sujects. The best pharmacy to handle oriental medicine was community pharmacy (36.2%). It was expressed the reason why many pharmacists have not been treated oriental medicine because lots of time needs for dispensing prescription from clinics in these 4 years after the separation of prescribing and dispensing. These results lead to the conclusion that the Oriental medicine at pharmacy will greatly increase within 5 years and will be very important portion for pharmacy management.

향사양위탕(香砂養胃湯) 전탕액이 노화주의 비장, 췌장, 위장 세포의 항산화능에 미치는 영향

최병철,안택원,Choi, Byoung-Chol,Ahn, Taek-Won 사상체질의학회 2008 사상체질의학회지 Vol.20 No.2

1. Objectives The purpose of this study was to observe the anti-oxidant effects of Hyangsayangyi-tang(HY) in SD rats. 2. Methods This experiment was used the tissue of stomach, spleen and pancreas cells of 6, 52 and 68 weeks old SD rats. Each age group was again divided into three groups. One group, as normal group, was not-treated cells, another group, as control group, was saline-treated cells, and the last group, as experimental group, was HY-treated cells. After culture for 48 hours, each groups measured the level of SOD, GSH, MDA and NO in the tissue of stomach, spleen and pancreas cells. 3. Results and Conclusions The activity of SOD were significantly increased in spleen cell of 52, 68 w-HY group, pancreas cell of 68 w-HY group and in stomach cell of 52, 68 w-HY group compared with those of the normal and the control groups. The level of GSH were significantly increased in spleen cell of 52, 68w-HY group and in pancreas cell of 68w-HY group compared with those of the normal and the control groups. The level of MDA were significantly decreased in pancreas cell of 68 w-HY group compared with those of the normal and the control groups. The level of NO were significantly decreased in spleen cell of 68 w-HY group, pancreas cell of 52, 68w-HGD groups compared with those of the control groups. According to results, HY showed anti-oxidant effect. Investigation into the clinical use of the HY is suggested for future research.

지능형 차량 보안 기술 동향

최병철,한승완,정병호,김정녀,Choi, B.C.,Han, S.W.,Chung, B.H.,Kim, J.N. 한국전자통신연구원 2007 전자통신동향분석 Vol.22 No.1

국내외적으로 지능형 차량 및 텔레매틱스/ITS 연구 개발을 통해서 차량에 IT 기술 접목을 위한 노력을 가속화하고 있다. 우리나라의 경우 산업자원부가 미래 10대 전략품목으로 자동차 부분에서 지능형 차량을 선정하였으며, 정보통신부는 u-IT839의 핵심서비스로 텔레매틱스/ITS 서비스를 추진하고 있다. EU는 i2010 Flagship에서 intelligentcar initiative 프로젝트를 통해 지능형 차량 및 보안을 위한 전략 수립과 세부과제를 수행하고 있다. 또한, IEEE 802.11p/P1609(WAVE)와 ISO TC204/WG16CALM에서는 차량 통신 보안 및 서비스에 대해서 고려하고 있다. 현재 지능형 차량과 관련하여서는 다양한 사업 모델이 제시되고 있으며, 자동차 업계의 BM과 이동통신 업계의 AM이 동반 성장하고 있다. 본 기고문은 지능형 차량 및 텔레매틱스/ITS와 관련한 보안 기술 동향을 살펴본다.

Ni, Ru-ZSM-5를 첨가한 NSR 촉매의 NOx 정화 특성

최병철,이춘희,정종우,Choi, Byung-Chul,Lee, Choon-Hee,Jeong, Jong-Woo 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.5

In this study, we investigated the conversion performance of de-NOx catalyst for lean-burn natural gas engine. As a de-NOx catalyst, NOx storage reduction catalyst was composed of Pt, Pd and Rh with washcoat including Ba and Ni, Ru-ZSM-5. Ni, Ru-ZSM-5, which was regarded as a NOx direct decomposition catalyst, was made up of ion exchanged ZSM-5 by 5wt.% Ni or Ru. The performance of de-NOx catalyst was evaluated by NOx storage capacity and catalytic reduction in air/fuel, $\lambda=1.6$. The catalytic reaction was also observed when the added fuel was supplied to fuel rich atmosphere by fuel spike period of 5 seconds. The NOx conversion of the catalysts with Ni-ZSM-5 or Ru-ZSM-5 was mainly caused by the effect of NOx adsorption of Ba rather than the catalytic reduction of Ni, Ru-ZSM-5. Ni, Ru-ZSM-5 catalysts can not use for the NSR catalyst because they have quick process in thermal deactivation.