• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.484-490
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• 1997

In an attempt to investigate the effects of white ginseng on the proliferation and the nitric oxide(NO) secretion of mouse peritoneal macrophages, which are the first mai or defense phagocytes in the immune system, the studies have been carried out. In the macrophage proliferation assay using the $^3$H-thymidine incorporation, the total saponin or Ginsenoside Rb$_2$ were added to the medium at the concentration of 0 to 256$\mu\textrm{g}$/$m\ell$. DNA synthesis of the macrophage was increased at 64$\mu\textrm{g}$/$m\ell$ of total saponin and either 16$\mu\textrm{g}$/$m\ell$ or 64$\mu\textrm{g}$/$m\ell$ of Ginsenoside Rb$_2$, respectively. Also, the effect o(white ginseng on the nitric oxide secretion of the macrophages was investigated. The addition of either total saponin or Ginsenoside Rb$_2$ at the concentration of 20$\mu\textrm{g}$/$m\ell$ significantly increased the secretion of NO from the macrophages. The nitric oxide synthase (NOS) gene expression which is responsible for the synthesis of the nitric oxide has been studied using reverse transcription polymerase chain reaction. In RT-PCR, the $\beta$-actin and nos gene expression have been analyzed. 20$\mu\textrm{g}$/$m\ell$ of either total saponin or Ginsenoside Rb$_2$ increased nos gene expression of the macrophages.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.685-691
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• 2005

Growth and DNA synthesis inhibitory effects of doenjang methanol extract and its solvent fractions on AGS human gastric adenocarcinoma cells, Hep 3B human hepatocellular carcinoma cells, HT-29 human colon cancer cells and MG-63 human osteosarcoma cells were studied. The treatment of doenjang methanol extract ($ 200{\mu}g/ml $) with the AGS, Hep 3B, HT-29 and MG-63 cancer cells after 6 days of incubation inhibited the growth of cancer cells by $32\%$, $51\%$, $84\%$ and $33\%$, respectively. To separate active compounds of doenjang, doenjang methanol extract was fractionated with dichloromethane, ethylacetate, and buthanol. Among the solvent fractions, the dichloromethane and ethylacetate fractions showed the highest growth inhibitory effects on various cancer cells. For example, the dichloromethane and ethylacetate fractions ($200a{\mu}g/ml$) sig-nificantly inhibited the growth of various cancer cells by $89\∼96\%$ and$62\∼86\%$, respectively. DNA synthesis of AGS and Hep 3B cancer cells was significantly inhibited by adding dichloromethane fraction ($200{\mu}g/ml$) up to $94\%$ and $80\%$, respectively. Similarly, the ethylacetate fraction ($ 200\mug/ml $) showed a $ 95\% $ inhibition rate of DNA synthesis in AGS cells. These results suggest that the dichloromethane and ethylacetate fractions have specific active compounds, which will explain this anticancer effect of doenjang.

• YAKHAK HOEJI
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• v.35 no.4
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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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• v.18 no.6
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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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• v.19 no.1
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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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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• 2000.10a
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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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• v.22 no.1
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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.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.4
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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.