• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.353-358
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• 2010

This study demonstrates the ability of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, to inhibit LPS-induced expression of iNOS gene and activation of NF-${\kappa}B$/Rel in RAW 264.7 cells. Immunohisto-chemical staining of iNOS and Western blot analysis showed magnolol to inhibit iNOS gene expression. Reporter gene assay and electrophoretic mobility shift assay showed that magnolol inhibited NF-${\kappa}B$/Rel transcriptional activation and DNA binding, respectively. Since p38 is important in the regulation of iNOS gene expression, we investigated the possibility that magnolol to target p38 for its anti-inflammatory effects. A molecular modeling study proposed a binding position for magnolol that targets the ATP binding site of p38 kinase (3GC7). Direct interaction of magnolol and p38 was further confirmed by pull down assay using magnolol conjugated to Sepharose 4B beads. The specific p38 inhibitor SB203580 abrogated the LPS-induced NF-${\kappa}B$/Rel activation, whereas the selective MEK-1 inhibitor PD98059 did not affect the NF-${\kappa}B$/Rel. Collectively, the results of the series of experiments indicate that magnolol inhibits iNOS gene expression by blocking NF-${\kappa}B$/Rel and p38 kinase signaling.

• BMB Reports
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• 제38권4호
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• pp.474-480
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• 2005

Curcumin, a major active component of turmeric, has been identified as an inhibitor of the transcriptional activity of activator protein-1 (AP-1). Recently, it was also found that curcumin and synthetic curcumin derivatives can inhibit the binding of Jun-Fos, which are the members of the AP-1 family, to DNA. However, the mechanism of this inhibition by curcumin and its derivatives was not disclosed. Since the binding of Jun-Fos dimer to DNA can be modulated by redox control involving conserved cysteine residues, we studied whether curcumin and its derivatives inhibit Jun-Fos DNA binding activity via these residues. However, the inhibitory mechanism of curcumin and its derivatives, unlike that of other Jun-Fos inhibitors, was found to be independent of these conserved cysteine residues. In addition, we investigated whether curcumin derivatives can inhibit AP-1 transcriptional activity in vivo using a luciferase assay. We found that, among the curcumin derivatives examined, only inhibitors shown to inhibit the binding of Jun-Fos to DNA by Electrophoretic Mobility Shift Assay (EMSA) inhibited AP-1 transcriptional activity in vivo. Moreover, RT-PCR revealed that curcumin derivatives, like curcumin, downregulated c-jun mRNA in JB6 cells. These results suggest that the suppression of the formation of DNA-Jun-Fos complex is the main cause of reduced AP-1 transcriptional activity by curcuminoids, and that EMSA is a suitable tool for identifying inhibitors of transcriptional activation.

• Fibers and Polymers
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• 제3권1호
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• pp.18-23
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• 2002

The structure development and dynamic properties of fibers produced by high-speed spinning of P(EN-ET) random copolymers were investigated. The as-spun fibers were found to remain amorphous up to the spinning speed of 1500 m/min, and subsequent increases in speed resulted in the crystalline domains containing primarily $\alpha$ crystalline modification of PEN. The f modification was not found up to spinning speeds of 4500 m/min. On the other hand, annealing of constrained fibers spun at the 2100 m/min at 180,200, and 240^{\circ}C$ exhibited $\beta$-form crystalline structure, while the annealed fibers spun in 600-1500 m/min range exhibited dominantly $\alpha$-form. However $\beta$-form crystals disappeared above the spinning speed of 3000 m/min. With increasing spinning speeds from 600 to 4500 m/min, the storage modulus of as-spun fibers increased continuously and reached a value of about 10.4 spa at room temperature. The tan $\delta$curves showed the $\alpha$-relaxation peak at about 155-165^{\circ}C$, which is considered to correspond to the glass transition. The $\alpha$-relaxation peaks became smaller and broader, and shift to higher temperatures as the spinning speed increases, meaning that molecular mobility in the amorphous region is restricted by increased crystalline domain.

• BMB Reports
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• 제29권2호
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• pp.116-121
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• 1996

In earlier studies, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C-3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3 (N to C-terminal) and C3-E. The hybrid thioredoxins were overexpressed in E. coli from the cloned chimeric thioredoxin genes by a T7 promoter/polymerase system. To investigate the structure-function relationship of thioredoxin, we purified the E-C3 hybrid thioredoxin through ammonium sulfate fractionation, DEAE-cellulose chromatography, and Sephadex G-50 gel filtration. Its purity was examined on SDS-polyacrylamide gel electrophoresis and the molecular weight of the purified E-C3 hybrid thioredoxin was estimated to be 12,000. On native polyacrylamide gels, the purified E-C3 hybrid thioredoxin shows a much lower mobility than E. coli thioredoxin. E-C3 hybrid thioredoxin exhibits a 40-fold lower catalytic efficiency with E. coli thioredoxin reductase than E. coli thioredoxin. It was shown to catalyze the reduction of insulin disulfide by dithiothreitol. The purified E-C3 hybrid thioredoxin was also characterized in other aspects.

• Journal of the Korean Vacuum Society
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• 제9권2호
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• pp.116-121
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• 2000

We measured surface photovoltage (SPV) of $Al_{0.24}Ga_{0.76}As/GaAs$ epilayer grown by molecular beam epitixy (MBE). The band gap energies of $Al_{0.24}Ga_{0.76}As/GaAs$ epilayer, GaAs substrate and buffer layer obtained from SPV signals are 1.70, 1.40 and 1.42 eV, respectively. There results are in good agreements with photoreflectance (PR) measurement. The measured SPV intensity of GaAs substrate is three times larger than $Al_{0.24}Ga_{0.76}$Asepilayer by carrier mobility difference. The parameters of Varshni equation were determined from the SPV spectra as a function of temperature.

• Journal of Environmental Health Sciences
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• 제14권1호
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• pp.33-38
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• 1988

Natural mineral water is generally quite different from ordinary drinking water due to its original nature and various properties. The complexity of natural mineral water requires, therefore, not only to identify its nature and proper characteristics, but also to classify them by a reasonable scientific basis of comparison. The study was concentrated on a possible classification technique to natural mineral waters by their constitutions and physico-ehemical properties. The classification was carried out by the computation of such numerical parameters as ionic equivalent percentage, electrolytic conductance or mobility, ionic molecular weight, molecular concentration, equivalent conductivity and degree of ionization in consideration of the determinative criteria as follows -particular single element or molecule -major components of natural waters as bicarbonate, sulphate, chloride,caloride, calcium, magnesium, and sodium -moleculat concentration related to blood osmotic pressure -water temperature at emergence from spring -contents of free carbon dioxide (CO2) -pH value of water -total dissolved solids or salts (NaCl) The results obtained proved out to be clearly distinguhhable from ordinary drinking water as far as concern natural mineral water as an example on the subject -simple water -bicarbonate-predominating water -cold spring -carbonated-non gaseous water -weak alkaline water -non saline water Putting these various results together, the sample turned out to be a kind of natural mineral water that can be used as a drinking water if microbiologically safe.

• BMB Reports
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• 제46권11호
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• pp.544-549
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• 2013

High mobility group box 1 (HMGB1) is involved in the pathogenesis of vascular diseases. Unlike activated protein C (APC), the activation of PAR-1 by thrombin is known to elicit proinflammatory responses. To determine whether the occupancy of EPCR by the Gla-domain of APC is responsible for the PAR-1-dependent antiinflammatory activity of the protease, we pretreated HUVECs with the PC zymogen and then activated PAR-1 with thrombin. It was found that thrombin downregulates the HMGB1-mediated induction of both TNF-${\alpha}$ and IL-6 and inhibits the activation of both p38 MAPK and NF-${\kappa}B$ in HUVECs pretreated with PC. Furthermore, thrombin inhibited HMGB1-mediated hyperpermeability and leukocyte adhesion/migration by inhibiting the expression of cell adhesion molecules in HUVECs if EPCR was occupied. Collectively, these results suggest the concept that thrombin can initiate proinflammatory responses in vascular endothelial cells through the activation of PAR-1 may not hold true for normal vessels expressing EPCR under in vivo conditions.

• Parasites, Hosts and Diseases
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• 제42권2호
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• pp.57-60
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• 2004

A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

• Journal of Advanced Marine Engineering and Technology
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• 제34권2호
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• pp.296-302
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• 2010

If the fiber reinforced plastic is exposed to the moisture for a long period of time, most of moisture absorption occurs on the resin place, thus dropping cohesiveness between the molecules as the water molecules permeated between high molecular chains grant high molecular mobility and flexibility. Also as the micro crack occurs due to the permeation of moisture on the interface of glass fiber and epoxy resin, it is developed to the overall damage of interface place. Hence, the study on absorption is essential as the mechanical and physical properties of fiber reinforced composites are reduced. However, the study on absorption has the inconvenience needing to expose composite materials to fresh water or seawater for 1 month or up to 1 year. Therefore, this study has exposed fiber reinforced composites to fresh water and has developed a model with an accuracy of 98% after comparing the analysis value obtained by using ANSYS while basing on the experimental value of property decline by absorption and the basic properties of glass fiber and epoxy resin used in the experiment.

• Journal of the Korean Institute of Telematics and Electronics D
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• 제34D권7호
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• pp.56-61
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• 1997

I $n_{0.53}$G $a_{0.47}$As/I $n_{0.52}$A $l_{0.48}$As pseudomorphic high electron mobility transistor (P-HEMT) structures were grown on semi-insulating InP substrates by molecular beam epitzxy method. The hall effect measuremetn was used to measure the electrical properties and the photoluminescence (PL) measurement was used to measure the electrical properties and the photoluminescence(PL) measurement for optical propety. By the cross-sectional transmission electron microscopy (XTEM) investigation of the V and X shape defects including slip with angle of 60.deg. C and 120.deg. C to surface in the sampel, the defects formation mecahnism in the I $n_{0.52}$A $l_{0.48}$As epilayers on InP substrates could be explained with the different thermal expansion coefficients between I $n_{0.52}$A $l_{0.48}$As epilayers and InP substrate.d InP substrate.