• Natural Product Sciences
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• v.23 no.2
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• pp.92-96
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• 2017

A sesquiterpene was purified from Artemisia iwayomogi methanolic extract during the course of searching anti-inflammatory principle from medicinal plants. A sesquiterpene identified as armefolin inhibited the production of nitric oxide (NO) and attenuated inducible nitric oxide synthase (iNOS) protein level in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Armefolin also down-regulated mRNA expressions of iNOS and pro-inflammatory cytokines, interleukin-$1{\beta}$ and interleukin-6 in LPS-activated macrophages. Moreover, armefolin suppressed the degradation of inhibitory-${\kappa}B{\alpha}$ (I-${\kappa}B{\alpha}$) in LPS-activated macrophages. These data suggest that armefolin from A. iwayomogi can suppress the LPS-induced production of NO and the expression of iNOS gene through inhibiting the degradation of I-${\kappa}B{\alpha}$. Taken together, armefolin from A. iwayomogi might be a candidate as promising anti-inflammatory agent.

• Membrane Journal
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• v.17 no.3
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• pp.244-253
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• 2007

This research investigated the effect of a photocatalytic reaction on nanofiltration(NF) membrane fouling by natural organic matter(NOM). The photocatalytic degradation was very effective for destruction and transformation of NOM and was carried out by titanium dioxide($TiO_2$) and $TiO_2$-immobilized bead as a photocatalyst. In order to compare their phtocatalytic properties, the photocatalytic degradation of humic acid in the presence of calcium ion was used as a model reaction. After the photocatalytic degradation the membrane fouling was dramatically decreased.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.475-482
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• 2014

The metabolic pathway of eugenol degradation by thermophilic Geobacillus sp. AY 946034 strain was analyzed based on the lack of data about eugenol degradation by thermophiles. TLC, GC-MS, and biotransformation with resting cells showed that eugenol was oxidized through coniferyl alcohol, and ferulic and vanillic acids to protocatechuic acid before the aromatic ring was cleaved. The cell-free extract of Geobacillus sp. AY 946034 strain grown on eugenol showed a high activity of eugenol hydroxylase, feruloyl-CoA synthetase, vanillate-O-demethylase, and protocatechuate 3,4-dioxygenase. The key enzyme, protocatechuate 3,4-dioxygenase, which plays a crucial role in the degradation of various aromatic compounds, was purified 135-fold to homogeneity with a 34% overall recovery from Geobacillus sp. AY 946034. The relative molecular mass of the native enzyme was about $450{\pm}10$ kDa and was composed of the non-identical subunits. The pH and temperature optima for enzyme activity were 8 and $60^{\circ}C$, respectively. The half-life of protocatechuate 3,4-dioxygenase at the optimum temperature was 50 min.

• Natural Product Sciences
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• v.27 no.3
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• pp.151-160
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• 2021

Under some pathological conditions such as osteoarthritis, matrix metalloproteinases (MMPs) including MMP-13 have an important role in degrading cartilage materials. When the regulatory effects of some herbal extracts on MMP-13 expression were examined to evaluate the cartilage-protective potential, the ethanol extract of the radix of Viscum album was found to strongly downregulate MMP-13 induction in IL-1β-treated chondrocytes, SW1353 cells. Based on this finding, activity-guided separation was carried out, which yielded five constituents identified as 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)heptane (1), hesperetin-7-glucoside (2), syringin (3), homoflavoyadorinin B (4), and 4,4'-dihydroxy-3,6'-dimethoxychalcone-2'-glucoside (5). Of these, 1 and 5 significantly inhibited MMP-13 expression in SW1353 cells, with 5 being the most potent. Compound 5, a chalcone derivative, showed the downregulation of MMP-13 at 20 - 100 μM. The mechanism study revealed that 5 exerted MMP-13 down-regulatory action, at least in part, by interrupting the signal transducer and activator of transcription 1 (STAT1) activation pathway. Furthermore, this compound protected against cartilage degradation in an IL-1-treated rabbit cartilage explant culture. All these findings demonstrated for the first time that Viscum album and its constituents, especially chalcone derivative (5), possessed cartilage-protective activity. These natural products may have the potential for alleviating cartilage degradation.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.127-132
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• 2011

Humic substances is accounted for for the largest proportion in natural organic matter(NOM) and NOM is widely distributed in varying concentration in all aquatic and soil. They can affect water quality adversely in several ways by contributing undesirable color, complexing with metal and yielding metal concentrations exceeding normal solubility. Ozonation is one of the efficient treatments for degradation of humic substances which cause some problems in water treatment. Especially, the combination of ozone and granular activated carbon was applied to degradation humic acid in aquatic system. The aim of this work to test the available of acid-treated granular activated carbon as catalyst in the ozonation of humic acid.

• Parasites, Hosts and Diseases
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• v.40 no.2
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• pp.93-99
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• 2002

The effect of a secretory proteinase from the pathogenic amoebae Acanthamoeba castellanii on host's defense-oriented or regulatory proteins such as immunoglobulins, interleukin-1, and protease inhibitors was investigated. The enzyme was found to degrade secretory immunoglobulin A (slgA), IgG, and IgM. It also degraded $interleukin-1{\alpha}$ ($IL-l{\alpha}$) and $IL-l{\beta}$. Its activity was not inhibited by endogenous protease inhibitors, such as ${\alpha}$2-macroglobulin, ${\alpha}l-trypsin$ inhibitor, and ${\alpha}2-antiplasmin$. Furthermore, the enzyme rapidly degraded those endogenous protease inhibitors as well. The degradation of host's defense-oriented or regulatory proteins by the Acanthanoeba proteinase suggested that the enzyme might be an important virulence factor in the pathogenesis of Acanthamoeba infection.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.417-422
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• 1999

Algin and chitosan are known as biodegradable natural polymers. PVA is useful for the production of water soluble packaging, paper, textile sizes. PVA/Algin and PVA/chitosan films were prepared by solution blends method in the weight ratio of chitosan, algin for the purpose of useful biodegradable films. Thermal and mechanical properties of blend films such as DSC, impact strength, tensile strength and morphology by SEM were determined. As a result, The ratio of 10.0wt% PVA/chitosan films were similar to PVA at thermal and mechanical properties. PVA/Algin films were found that phase separation was occured as more than 25wt% increasing the blend ratio of algin. PVA/Algin films were observed to be less partially compatibility than 10wt% increasing the blend ratio of algin by DSC, mechanical properties and SEM. Blend films were completely degraded pH 4.0 better than 7.0, 10.0 in the buffer solution. Also, they were rapidly degraded in the enzyme( glucosidase) solution better than pH solution by enzymolysis.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.5-8
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• 2012

Haze is an extreme reason of the reduction of contrast when capturing image in the outdoor. Recently, there are several single image dehazing techniques, but they are not robust in dynamic variations of natural environment caused by the thickness, coverage of haze and appearance of sunlight. In this paper, we propose an effective and robust method to restore degradation of hazy image. Compare with conventional methods, our proposal have better performance and computation time.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.93-99
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• 1998

Mathematical model can be obtained by physical law or engineering theory. However it is always incomplete expression of the real system. In active controls to suppress vibration due to earthquake or wind load, modeling errors can often cause the problems of instability and performance degradation. In this paper, robust optimal controller design method using H$\infty$ control theory is developed for the systems which have uncertain natural frequency and design constraints. Numerical results show that the proposed H$\infty$ controller can avoid the performance degradation due to several errors and has better performance than conventional LQR method.

• Journal of Microbiology
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• v.45 no.4
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• pp.281-285
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• 2007

Cold environments, including polar and alpine regions, are colonized by a wide diversity of micro-organisms able to thrive at low temperatures. There is evidence of a wide range of metabolic activities in alpine cold ecosystems. Like polar microorganisms, alpine microorganisms playa key ecological role in their natural habitats for nutrient cycling, litter degradation, and many other processes. A number of studies have demonstrated the capacity of alpine microorganisms to degrade efficiently a wide range of hydrocarbons, including phenol, phenol-related compounds and petroleum hydrocarbons, and the feasibility of low-temperature bioremediation of European alpine soils by stimulating the degradation capacity of indigenous microorganisms has also been shown.