• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.414-420
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• 2015

Flavonoids, such as fisetin (3,7,3',4'-tetrahydroxyflavone), are plant secondary metabolites. It has been reported that fisetin is able to perform numerous pharmacological roles including anti-inflammatory, anti-microbial, and anti-cancer activities; however, the exact anti-inflammatory mechanism of fisetin is not understood. In this study, the pharmacological action modes of fisetin in lipopolysaccharide (LPS)-stimulated macrophage-like cells were elucidated by using immunoblotting analysis, kinase assays, and an overexpression strategy. Fisetin diminished the release of nitric oxide (NO) and reduced the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-${\alpha}$, and cyclooxygenase (COX)-2 in LPS-stimulated RAW264.7 cells without displaying cytotoxicity. This compound also blocked the nuclear translocation of p65/nuclear factor (NF)-${\kappa}B$. In agreement, the upstream phosphorylation events for NF-${\kappa}B$ activation, composed of Src, Syk, and I${\kappa}B{\alpha}$, were also reduced by fisetin. The phospho-Src level, triggered by overexpression of wild-type Src, was also inhibited by fisetin. Therefore, these results strongly suggest that fisetin can be considered a bioactive immunomodulatory compound with anti-inflammatory properties through suppression of Src and Syk activities.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.709-713
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• 1997

For the investigation of bioactive natural products with hypoglycemic effect, we have evaluated various extracts of Pulsatillae Radix(Ranunculaceae), which has been used in traditional medicine for hematochezia due to intense evil heat, malaria, chills and fever, epistaxis and internal hemorrhoids. The ethylacetate extract of the radix of this plant was found to show a significant hypoglycemic effect on alloxan diabetogenic mice. Using bioactivity-guided chromatographic purification of the ethylacetate extract, hypoglycemic constituent: 2${\beta}$, 3${\beta}$, 14${\alpha}$, 20, 22R, 25-hexahydroxy-cholest-7-en-6-one was isolated and structurally identified by physico-chemical properties and spectroscopic evidences.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.496-501
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• 2007

In order to enhance sintering characteristics on the $ZnO-Pr_6O_{11}$ based multilayer chip varistors (MLVs), a response surface analysis using central composite design method were carried out. As a result, varistor voltage($V_{1mA}$), nonlinear coefficient ($\alpha$), leakage current ($I_L$) and capacitance (C) were considered to be mainly affected by sintered temperature and holding time. MLVs sintered at $1200^{\circ}C$ and above $1200^{\circ}C$ revealed poor electrical characteristics, possibly due to the reaction between electrode materials(Pd) and $ZnO-Pr_6O_{11}$ based ceramics. On the sintering temperature range $1150{\sim}1175^{\circ}C$, nonlinear coefficient ($\alpha$) and leakage current ($I_L$) were shown to be $60{\sim}69$ and below $0.3{\mu}A$, respectively. In particular, MLVs sintered at $1175^{\circ}C$, 1.5 hr and $2^{\circ}C/hr$ (cooling speed) showed stable ESD(Electrical Static Discharge) characteristics under the condition of 10 times at 8 Kv with deviation varistor voltage, and deviation nonlinear coefficient were 0.3% and 0.33% (at positive), 0.55% (at negative), respectively.

• Bulletin of the Korean Mathematical Society
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• v.39 no.4
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• pp.577-587
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• 2002

Let A be a commutative ring and M an Artinian .A-module. Let $\sigma$ be a torsion radical functor and (T, F) it's corresponding partition of Spec(A) In [1] the concept of Cohen-Macauly modules was generalized . In this paper we shall define $\sigma$-co-Cohen-Macaulay (abbr. $\sigma$-co-CM). Indeed this is one of the aims of this paper, we obtain some satisfactory properties of such modules. An-other aim of this paper is to generalize the concept of cograde by using the left derived functor $U^{\alpha}$$_{I}$(-) of the $\alpha$-adic completion functor, where a is contained in Jacobson radical of A.A.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.810-812
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• 1998

We studied on the $\pi$-A isotherm of the L-$\alpha$-DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption with the UVspectrometer. We made structures of metal(Au)/organic thin films (L-$\alpha$-DLPC)/Metal(Au), the number of accumulated layers are 3. And I-V characteristic of the device examined.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.10
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• pp.665-674
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• 2000

This paper deals the HVDC system stability according to controller types. In this paper, in order to evaluate the stability, some important properties of the HVDC. such as $d{\tau}/d{\alpha}\;,\;dV/d{\alpha}$ and dP/dI stability in different control modes, are analysed. Furthermore, Maximum available power according to controller types are calculated. This paper shows a generated formulation of control sensitivity for control modes, aids in the design of the controller and the operating mode determination. Finally, a simulation is performed by Math/CAD, and a simulation results are verified.

• Bulletin of the Korean Chemical Society
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• v.3 no.3
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• pp.83-88
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• 1982

Viscosity and zeta-potential of 11.0 wt. % aqueous bentonite suspension containing various electrolytes and hydrogen-ion concentration were measured by using a Couette type automatic rotational viscometer and Zeta Meter, respectively. The effects of pH and elcctrolytes on the rheological properties of the suspension were investigated. A system, which has a large zeta-potcntial, has a small intrinsic relaxation time ${\beta}$ and a small intrinsic shear modulus $1/{\alpha}$ in the Ree-Eyring generalized viscosity equation, i.e., such a system has a small viscosity value, since ${\eta}={\beta}/{\alpha}$. In general, a stable suspension system has large zeta-potential. The stability condition of clay-water suspension can be estimated by viscometric method since stable suspension generally has small viscosity. The correlation between the stability, viscosity and zeta-potential has been explained by the Ree-Eyring theory of viscous flow.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.909-914
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• 1995

In order to investigate gelation properties of Gelation Properties of ${\alpha}-lactalbumin$(${\alpha}-La$), gelling times and protein solubilities of ${\alpha}-La$ gels prepared in 0.1 M Tris-HCI buffer(pH 8.0) followed by heating at $90^{\circ}C$ for 40 minutes under different ${\alpha}-La$ concentration, NaCl, $CaCl_2$, N-ethylmaleimide(NEM), and dithiothreitol(DTT) concentration were measured. Gelling times decreased with increasing concentration of ${\alpha}-La$, NaCl, $CaCl_2$, and DTT, but increased with increasing concentration of NEM. ${\alpha}-La$ solutions made from all treatments were gelled within 40 minutes with the exception of NEM at $20{\sim}50\;mM$. Solubilities decreased with increasing concentration of ${\alpha}-La$, NaCl, $CaCl_2$, and DTT, but the solubility of NEM-modified gels increased with increasing concentration of NEM. As the results, solubilities In standard buffer were $10.4{\sim}51.3%$, $9.2{\sim}35.4%$, $11.1{\sim}35.0%$, $8.0{\sim}9.5%$, and $96.8{\sim}56.2%$, respectively. Solubilities in standard buffer containing 8 M urea and 0.5% SDS were higher than those in standard buffer, and were $41.8{\sim}81.3%$, $41.9{\sim}64.1%$, $43.5{\sim}69.8%$, $29.6{\sim}38.5%$, and $77.4{\sim}98.9%$, respectively. Solubilities in the presence of DTT were almost close to 100% in all conditions. These results indicates that the gelation rate and solubility are influenced by many factors, i.e. protein concentration, kind and concentration of salts, concentration of thiol reagents. The solubility of gel decreased with increasing the gelation rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.521-526
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• 2007

The effects of red ginseng powder on hepatotoxicity in $benzo(\alpha)pyrene\;[B(\alpha)P]$-treated mice were investigated. Male ICR mice were pretreated with red ginseng powder (50 or 100 mg/kg/day, for 5 days, intraperitoneally) before treatment with $B(\alpha)P$ (0.5 mg/kg, i.p, single dose). The ability of red ginseng powder to protect against oxidative damage to the mouse liver was examined by determining the level of lipid peroxide, glutathione, and the antioxidant enzyme activities. The glutathione content depleted by $B(\alpha)P$ were significantly increased by red ginseng powder, but elevation of lipid peroxide content induced by $B(\alpha)P$ was decreased by red ginseng powder. The increased activities of superoxide dismutase, catalase and glutathione peroxidase after $B(\alpha)P$-treatment were decreased by the treatment of red ginseng Powder; however, glutathione S-transferase activity depleted by $B(\alpha)P$ were significantly increased. These results suggest that red ginseng powder can protect against $B(\alpha)P$ intoxification through its antioxidant properties.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.655-659
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• 1998

The effect of quenching speed of melt-spinning on intrinsic coercivity ($_iH_c$$) of annealed ribbons and the crystallization behavior from amorphous $Nd_{14.73}Fe_{78.67}B_{6.60}$ alloy have been studied. We have found that the intrinsic coecivity for annealed melt-spun ribbon is reduced with increasing of quenching rate. $\alpha$-Fe and $Fe_3B$ were formed as intermediate phases prior to the formation of $Nd_2Fe_{14}B$ phase during crystallization. The $Fe_3B$ is disappeared with crystallization of $Nd_2Fe_{14}B$ phase. But the $\alpha$-Fe phase is retained in fully crystallized ribbon by annealing. The intrinsic coercivity loss of annealed ribbon with increasing of quenching speed is believed to be due to existence of soft magnetic phase $\alpha$-Fe in annealed ribbons.