아가리쿠스 버섯 균사체 추출물 및 분획물의 항돌연변이원성 및 세포 독성 효과

오현택,김수현,유수정,함승시,Oh, Hyun-Taek,Kim, Soo-Hyun,Yoo, Su-Jung,Ham, Seung-Shi 동아시아식생활학회 2007 동아시아식생활학회지 Vol.17 No.4

This study was performed to observe the antioxidative effects, antimutagenic capacity, and cytotoxic activity of the 70% ethanol extract, and fractions, of Agaricus blazei Murill mycelium, using DPPH free radical scavenging ability, the Ames test, and SRB assay, respectively. Among the fractions, ethyl acetate showed the most effective antioxidative capacity according to the $RC_{50}$(73.6 $\mu$g/mL) of the scavenging effect on the DPPH radical. The inhibition rate of both the aqueous fraction and 70% ethanol extract(200 $\mu$g/plate) toward the Salmonella typhimurium TA100 strain was 94.6%, and it was 89.4% against the mutagenesis induced by MNNG(0.4 $\mu$g/plate). In addition, an identical concentration of the 70% ethanol extract in the TA98 strain, and the ethyl acetate fraction in the TA100 strain, showed inhibition rates of 80.3% and 76.9%, respectively, the highest activities against the mutagenesis induced by 4NQO(0.15 $\mu$g/plate). The cytotoxic effects of the 70% ethanol extract and its fractions increased with increasing sample concentration against human cervical adenocarcinoma(HeLa), human hepatocellular carcinoma(Hep3B), human breast adenocarcinoma(MCF-7), human stomach adenocarcinoma(AGS), and human lung carcinoma (A549). A 1 mg/mL concentration of the ethyl acetate fraction showed cytotoxicities of 77%, 83.8%, 82.1%, 83.1%, and 92.6% against HeLa, Hep3B, MCF-7, AGS and A549, respectively.

날개 길이방향 유동이 날개짓 운동의 공기역학적 특성에 미치는 효과

오현택(Hyun-Taek Oh),최항철(Hang-Cheol Choi),김광호(Kwang-Ho Kim),정진택(Jin Taek Chung) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

Flight performance of birds and insects is superior to conventional fixed wing aircrafts at low Reynolds number regime. While they flap their wings, aerodynamic characteristics such as span-wise flow and rotational circulation are appeared on the wing. To study on the effect of span-wise flow, 3-D flapping motion was compared with 2-D flapping motion. In 3-D flapping motion, the measured lift forces were increased until the angle of attack 50° at mid-stroke. But in 2-D flapping motion, the lift forces were decreased above the angle of attack 30° at mid-stroke. Also, the mean lift to drag ratio of 3-D flapping motion is higher than that of 2-D flapping motion.

지속가능경영과 지속가능성 측정

오현택(Hyun-Taek Oh) 청주대학교 경영경제연구소 2010 경영경제연구 Vol.33 No.1

산천어(Oncorhynchus masou) 에탄올 추출물의 in vitro 및 in vivo에서 항암활성

오현택(Hyun-Taek Oh),정미자(Mi-Ja Chung),함승시(Seung-Shi Ham) 한국식품영양과학회 2009 한국식품영양과학회지 Vol.38 No.2

산천어 70% 에탄올 추출물(MSE)이 암세포 성장억제와 Balb/c 마우스에서의 종양 성장 억제에 미치는 영향을 알아보았다. 인간 자궁암(HeLa), 간암(HepG2), 유방암(MCF-7), 위암(AGS), 폐암(A549) 세포 그리고 인간신장 정상세포(293)에 MSE을 처리했을 때 세포생존율이 감소하였고 이들 감소율을 MTT assay로 알아보았다. MSE는 정상세포 293에서보다 인간 암세포주인 MCF-7, A549, HepG2, AGS 그리고 HeLa세포에서 현저하게 더 높은 세포독성이 나타났다. 시료 최고농도인 1 ㎎/mL를 인간 폐암세포(A549), 유방암세포(MCF-7), 간암세포(HepG2) 및 위암세포(AGS)에 처리한 결과 각각 9.2%, 12.7%, 14.6% 및 16.9%의 세포 생존율을 나타내었다. 더하여 복수암 세포(sarcoma-180)를 이용한 실험동물(Balb/c mice)에서의 고형암 성장 억제 효과를 알아보았으며, 각각 25 ㎎/㎏ body weight와 250 ㎎/㎏ body weight의 MSE를 투여하였을 때 종양 성장 억제율은 각각 44.7%와 55.7%였다. 따라서 우리는 MSE가 암 예방을 위해 인간에게 유익한 기능성 소재일 것이라는 것을 제안하였다. The cytotoxic activity against human cancer cells and anti-tumor effect in Balb/c mice of a 70% ethanol extract from masou salmon (MSE) was investigated. The cancer cell lines including human breast adenocarcinoma (MCF-7), human lung carcinoma (A549), human hepatoblastoma (HepG2), human gastric carcinoma (AGS), human cervical adenocarcinoma (HeLa) and transformed primary human embryonal kidney (293) exposed to MSE decreased cell viability as indicated by the MTT assay. The MSE shows significant cytotoxicity on MCF-7, A549, HepG2, AGS and HeLa cells, and are more active than 293 cells. The treatment with 1 ㎎/mL MSE resulted in 9.2%, 12.7%, 16.6%, and 16.9% cell survival against A549, MCF-7, HepG2, and AGS cells, respectively. Moreover, anticancer effect in vivo of MSE was tested in the animal system using Balb/c mice transplanted sarcoma-180 cells. MSE showed inhibition of tumor growth and the rate of inhibition was 44.7% and 55.7% at the 25 mg/kg body weight and 250 ㎎/㎏ body weight, respectively. Thus, we suggest that MSE could be a beneficial material for human cancer prevention.

초음파를 이용한 다양한 고체추진제의 고압범위까지의 연소속도 측정 정밀도 분석

오현택(Hyun-Taek Oh),송성진(Sung-Jin Song),김학준(Hak-Joon Kim),고선필(Sun-Feel Ko),김인철(In-Chul Kim),유지창(Ji-Chang Yoo),정정용(Jung Yong Jung) 한국추진공학회 2008 한국추진공학회 학술대회논문집 Vol.2008 No.11

본 연구에서는 서로 다른 연소속도 범위를 갖는 다양한 고체추진제의 연소속도를 고압(~5,000 psia)까지 측정하였고, 측정된 연소속도의 자체적인 편차를 추진제 종류별, 압력별로 분석하여 초음파법의 측정 정밀도를 평가하였다. 또한 스트랜드 버너법을 이용한 연소속도 측정값과 상호 비교하여 두 측정 기법의 특성을 비교해보았다. In this study, we measured burning rates of solid propellants which has various burning rates until 5000 psia, and we evaluated measurement accuracy of ultrasonic method by analyzing error of burning rates. Also, We compared result of burning rates by using ultrasonic method with strand burner method so that characteristics of two measurements method are evaluated.

덕론의 스포츠윤리학적 함의

오현택(Hyun Taek Oh) 한국체육철학회 2006 움직임의철학 : 한국체육철학회지 Vol.14 No.1

날개의 종횡비가 날개 짓 운동의 공기역학적 특성에 미치는 영향

오현택(Hyun-Taek Oh),최항철(Hang-Cheol Choi),김광호(Kwang-Ho Kim),정진택(Jin Taek Chung) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

The lift and drag forces produced by a wing of a given cross-sectional profile are dependent on the wing planform and the angle of attack. Aspect ratio is the ratio of the wing span to the average chord. For conventional fixed wing aircrafts, high aspect ratio wings produce a higher lift to drag ratio than low ones for flight at subsonic speeds. Therefore, high aspect ratio wings are used on aircraft intended for long endurance. However, birds and insects flap their wings to fly in the air and they can change their wing motions. Their wing motions are made up of translation and rotation. Therefore, we tested flapping motions with parameters which affect rotational motion such as the angle of attack and the wing beat frequency. The half elliptic shaped wings were designed with the variation of aspect ratio from 4 to 11. The flapping device was operated in the water to reduce the wing beat frequency according to Reynolds similarity. In this study, the aerodynamic forces, the time-averaged force coefficients and the lift to drag ratio were measured at Reynolds number 15,000 to explore the aerodynamic characteristics with the variation of aspect ratio. The maximum lift coefficient was turned up at AR=8. The mean drag coefficients were almost same values at angle of attack from 10° to 40° regardless of aspect ratio, and the mean drag coefficients above angle of attack 50° were decreased according to the increase of aspect ratio. For flapping motion the maximum mean lift to drag ratio appeared at AR=8.

중소기업의 회계처리 및 세제지원 방향

오현택(Oh Hyun Taek) 한국중소기업학회 1998 中小企業硏究 Vol.20 No.2

N/A

체육학의 생산적 통섭 논의를 위한 기초

오현택(Oh, Hyun-Taek),정영우(Jung, Young-Woo) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.5

The purpose of this study was to consider the conditions that could live the consilience and result in developmental consilience in both sides of academic and practice in sports science from the viewpoint of the critical to existing studies of consilience in sports science. The main results of this study were as follow: First, must be necessary to discuss the consilience in sports science for improving the academical prestige of sports science in therms of academic and training the sport professional who have an ability to converge and so rise the social needs lately in terms of practice. Second, the basic conditions for developmental discussion about consilience in sports science were to close the distance between ‘two cultures’ that divided into the science and the humanities, to acknowledge and consider the various conditions for all kinds and forms of consilience as between disciplines in sports science, between sports science and the other disciplines, between fundamental and applied disciplines in sports science, and between theory and practice in sports science, and to solve the closure between disciplines in sports science and the absence of communication from that closure. Third, the practical tasks for the upcoming consilience in sports science were to collapse the boundaries between specialties in sports science, to reorganize the curriculum for cultivating men of talent who accustomed to consilience, and to collapse the boundaries between researchers in sports science for interchanging and mutual understanding between them.

덕론(德論)에 기초한 스포츠 상업주의 비판

오현택(Oh, Hyun-Taek) 한국사회체육학회 2014 한국사회체육학회지 Vol.0 No.58

The purpose of this study was to widen the critical discussionto sport commercialism and generate a sense of alarm to it. This study criticized sport commercialism base don theory of virtue and intended to reestablish the nature of sport that changed by sport commercialism. The pneetration of commercialism that disguised as a industrialization was attended by many evils and malaise in the sporting world. Therefore, we must be on our guard against the penetration of commercialism into sport and take precautions against it. The critics to bad effect of sport commercialism based on theory of virtue were as follows: First, sport commercialism failed to seek the intrinsic value of sport because it obstruct the pursuit o pfersonal meaning in sport participation. Second, sport commercialism diminished the value and meaning of sport because it pursuit excessively economic profits. And last, sport commercialism could not elucidate the nature of sport that established by social tradition because an economic point of view is the only standard that analyze and estimate the sport in sport commercialism.