• 동아시아식생활학회지
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• 제7권4호
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• pp.484-490
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• 1997

백삼성분이 탐식세포를 통한 면역반응조절에 어떠한 영향을 미치는가를 알아보기 위해 total saponin이나 ginsenoside Rb$_2$성분이 마우스 복강 탐식 세포의 증식과 nitric oxide(NO)분비 및 NOS 유전자 발현에 미치는 영향을 조사해 보았다. Total saponin 또는 ginsenoside Rb$_2$성분을 탐식세포 배양액에 0-256$\mu\textrm{g}$/$m\ell$ 농도로 첨가하여 배양한 후 $^3$H-thymidine incorporation법으로 분석을 실시한 결과 total saponin은 64$\mu\textrm{g}$/$m\ell$ 농도에서 세포내 DNA 합성을 증가시켰으며, ginsenoside Rb$_2$ 성분의 경우 16$\mu\textrm{g}$/$m\ell$ 또는 64$\mu\textrm{g}$/$m\ell$ 농도에서 DNA 합성이 증가되었다. 256$\mu\textrm{g}$/$m\ell$의 높은 농도에서 세포의 증식이 약간 저해되었지만 대조군에 비해 유의적인 감소는 보이지 않았다. NO 분비에 미치는 영향을 조사해 본 결과 20$\mu\textrm{g}$/$m\ell$ 농도의 백삼성분을 투여했을 때 NO분비가 대조군에 비해 유의적으로 증가하였다. Reverse transcription polymerase chain reaction (RT-PCR)을 이용하여 백삼성분에 의한NOS 유전자 발현의 정도를 조사한 결과 20$\mu\textrm{g}$/$m\ell$ 농도에서 nos gene발현이 대조군보다 증가되었다

• 생명과학회지
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• 제15권5호
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• pp.685-691
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• 2005

본 연구는 된장의 항암효과를 검토하기 위해서 된장 메탄올 추출물과 그 분획물들에 의한 여러 인체 암세포들의 성장 억제와 DNA합성 저해 실험을 행하였다. AGS 인체 위암세포를 이용하여 6일간 배양하여 된장의 메탄을 추출물 $200{\mu}g/ml$를 처리한 결과 $32\%$의 억제효과를 나타내었고 된장 메탄올의 분획물들 중 디클로로메탄층이 가장 높았으며 $200{\mu}g/ml $ 농도로 첨가했을 때 $90\%$의 위암세포 성장을 저해시켰고 에틸아세테이트 분획물을 동일 첨가농도로 투여했을 때 $62\%$의 저해효과를 보였다. 인체 간암세포인 Hep 3B의 경우, 첨가농도 $200{\mu}g/ml$에서 메탄올 추출물은 $51\%$로 암세포 증식을 억제하였으나 디클로로메탄, 에틸아세테이트 분획물의 저해효과가 각각 $89\%$, $86\%$로 매우 높았다. 인체의 결장암세포인 HT-29 세포의 경우, 첨가농도 $200{\mu}g/ml$에서 메탄올 추출물, 디클로로메탄, 에틸아세테이트 분획물은 각각 $84\%$,$91\%$, $71\%$로 암세포 증식을 억제하였다. MC-63 인체의 골육암 세포의 경우, 첨가농도 $200{\mu}g/ml$에서 메탄올 추출물은 $33\%$로 낮은 저해효과를 보였으나 메탄올 추출물의 분획물들 중에는 디클로로메탄 분획물이 $96\%$로 저해효과가 가장 높았으며, 다음으로 에틸아세테이트 분획물이 $71\%$로 암세포 증식을 억제시켰다 된장의 메탄올 추출물 중에서 암세포 증식 억제 효과에서 가장 컸었던 디클로로메탄 분획물과 에틸아세테이트 분획물을 AGS 위암세포에 투여한 2일 후에 세포내의 DNA 합성에 미치는 영향을 측정한 결과, 된장의 디클로로메탄 분획물 $50{\mu}g/ml $, $100{\mu}g/ml$, $200{\mu}g/ml$ 농도에서 각각 $ 66\%$, $73\%$, $94\%$로 DNA 합성이 감소되었고 된장의 에틸아세테이트 분획물 $50{\mu}g/ml$, $100{\mu}g/ml$,$200{\mu}g/ml $ 농도에서 각각 $57\% $, $93\%$, $95\%$의 DNA 합성 저해효과를 나타내었다. 인체 간암세포의 경우, 된장의 디클로로메탄 분획물은 $200{\mu}g/ml$ 농도에서 $ 80\% $의 높은 저해효과를 보였고 에틸아세테이트 분획물은$ 200\mug/ml $ 농도에서 $ 64\% $의 저해효과가 나타내었다. 이상의 얻어진 결과로 된장의 메탄올 추출물과 그 분획물은 여러 인체 암세포의 증식을 억제하고 DNA 합성도 저해하여 in vitro 상에서 암예방 효과 및 항암효과가 있는 것으로 추정된다.

• 약학회지
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• 제35권4호
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• pp.258-263
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• 1991

Seven drivatives of 2, 3-alkyl substituted aziridinecarboximidates were prepared from alkyl substituted alkene and cyanamide. Their ED$_{50}$ values against L$_{1210}$ cell in vitro were evaluated as 1.5 to 4 $\mu\textrm{g}$/ml.

• Archives of Pharmacal Research
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• 제18권6호
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• pp.440-448
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• 1995

Fitty two flavones were synthesized from polyoxygenated dibenzoylmethanes which were obtained by a modified Baker-Venkatarman rearrangement, of 2-benzoyl oxyacetophenones. The following flavones among them showed good cytotoxic activities against L1210 and HL60 cells ; 2'-benzoyloxy-5,7-dimethoxyflavone $(8.2{\mu}g/ml,{\;}5.0 {\mu}g/ml)$, 2'-benzyloxy-5,7,8-trimethoxyflavone $(5,9 {\mu}g/ml,{\;}11.0{\mu}g/ml,{\;}2.7{\mu}g/ml)$, 2'-hydroxy-5,7,8-trimethoxyflavone $(9.8{\mu}/ml,{\;}6.2{\mu}g/ml)$, 2'-benzyloxy-5-hydroxyflavone $(5.2 {\mu}g/ml,{\;}3.6{\mu}g/ml)$, and 5,2'-dihydroxyflavone $(5.1{\mu}g/ml,{\;}4.0{\mu}g/ml)$. Presence of 5-methoxy group potentiated the cytotoxic activity, while the existence of 7-methoxy group decreased the activity. 5-Hydroxy or methoxy activates 4-carbonyl group, while 7-methoxy group deactivates the acrbonyl group. From these observation it was concluded that the activation of carbonyl group at C-4 of a flavone is important for the enahncement of the cytotoxic activity. The presence of both 5-hydroxy and 2-benzyloxy-or 2-hydroxy group enhanced the antitumor activity; 2'-benzyloxy-5-hydroxy-7-methoxyflaone 9T/C=144%), 5.2'-dihydroxy-7-methoxyflavone (T/C=132%) and 5,2'-dihydroxy-6,78,6' trtramethoxyflvone (T/C = 172%) 2'hexanolytion of 5,2'-dihydroxy-flavones did not improve the natitumor activity; 2' hexanoyloxy-5-hydroxy-7-methoxyflavone showed T/C = 132%, about the same as that of 5,2'-dihydroxy-7-methoxyflvone (T/C=130%)

• Journal of Advanced Marine Engineering and Technology
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• 제19권1호
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• pp.60-70
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• 1995

In the field of marine transportation the energy saving is one of the most important factors for profit. In order to reduce the fuel oil consumption the ship's propulsion efficiency must be increased as much as possible. The propulsion efficiency depends upon a combination of an engine and a propeller. The propeller has better efficiency as lower rotational speed. This situation led the engine manufacturers to design the engine that has lower speed, longer stroke and a small number of cylinders. Consequently the variation of rotational torque became larger than before because of the longer delay-time in the fuel oil injection process and an increased output per cylinder. As this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variation of the delay-time and the parameter pertubation. In this paper we consider the delay-time and the perturbation of engine parameters as the modeling uncetainties. Next we design the controller which has zero offset in steady state engine speed, based on the two-degree-of-freedom control theory and $\mu$-synthesis. Thd validity of the controller is investigated through the response simulation. We use a personal computer and an analog computer as the digital controller and the engine (plant) part respectively. And, we certify that the designed controller maintains its performance even though the engine parameters may vary.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.925-933
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• 2006

Using the physics-based model for the vibration isolation system, the model uncertainties are described. With the model including parameter perturbations, the robust controller to meet the robust performance and stability is designed through $\mu$-synthesis by DK-iteration. The order of controller is reduced by virtue of Hankel norm approximation technique to allow the efficient implementation in the real-time experimental environment without any performance degradation. The performance of the reduced $\mu$-controller is accessed in comparison with the original one. The experiments validate the superiority of the proposed control scheme against the model uncertainties and its applicability with varying payload.

• 한국소음진동공학회논문집
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• 제16권12호
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• pp.1262-1271
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• 2006

Using the physics-based model for the vibration isolation system, the model uncertainties are described. With the model including parameter perturbations, the robust controller to meet the robust performance and stability is designed through $\mu$-synthesis by DK-iteration. The order of controller is reduced by virtue of Hankel norm approximation technique to allow the efficient implementation in the real-time experimental environment without any performance degradation. The performance of the reduced $\mu$-controller is accessed in comparison with the original one. The experiments validate the superiority of the proposed control scheme against the model uncertainties and its applicability with varying payload.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.498-498
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• 2000

A study on the robust control of a composite beam with a distributed PVDF sensor and piezo-ceramic actuator is presented in this paper. 1st and 2nd natural frequencies are considered in the modeling, because robust control theory which has robustness to structured uncertainty is adopted to suppress the vibration. If the controllers designed by H$_{\infty}$ theory do not satisfy control performance, it is improved by $\mu$-synthesis method with D-K iteration so that the $\mu$-controller based on the structured singular value satisfies the nominal performance and robust performance. Simulation and experiment were carried out with the designed controller and the verification of the robust control properties was presented by results.

• Archives of Pharmacal Research
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• 제22권1호
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• pp.25-29
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• 1999

Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp. and jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA). The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 ${\mu}g/ml$, which that of ciprofloxacin was 0.391~3.125${\mu}g/ml$. Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 ${\mu}g/ml$. These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

• 대한한방부인과학회지
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• 제24권4호
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• pp.1-9
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• 2011

Purpose: Wogonin is an active component isolated from scutellariae radix. This study was conducted to evaluate the inhibitory effect of wogonin mixed with hydrogel on osteoclast differentiation. Methods: It was performed to estimate cytotoxicity of Wogonin alginate hydrogel disk(WHD) in BMMs stimulated with RANKL, M-CSF. ROS synthesis and actin ring formation were analysed to observe the effect of WHD. Results: WHD has no cytotoxicity at the concentration of 0.1 ${\mu}g/ml$ or lower. 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the synthesis of ROS and 0.1 ${\mu}g/ml$, 1 ${\mu}g/ml$ WHD restrained the formation of actin ring. Conclusions: WHD has the inhibitory effect of osteoclast differentiation and bone resorption. Further studies are needed to treat osteoporosis by herbal medicine.