• Korean Journal of Materials Research
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• v.13 no.4
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• pp.251-258
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• 2003

The effects of the salt and the precursor pH on the synthesizing behavior and the morphology of mullite have been studied. Two kinds of mullite precursor sols were prepared by the dissolution of two kinds of salt (aluminum nitrate enneahydrate, Al($NO_3$)$_3$ㆍ$9H_2$O; type I and aluminum sulfate 14∼18 water, (SO$Al_4$)$_3$$\cdot$$14∼18H_2$O; type II) into the mixture of colloidal silica sol, respectively. Precursor pH of the sols was controlled to the acidic (pH= 1.5∼2) and basic (pH= 8.5∼9) conditions. The co-products with nitrate and sulfate were completely eliminated at $500^{\circ}C$ and $850^{\circ}C$, respectively, which was confirmed by TG/DTA results. The synthesizing temperature of mullite phase was found to be above $1200^{\circ}C$ for pH= 1.5∼2 and above $1300^{\circ}C$ for pH= 8.5∼9 in type I. However, in type II, the synthesizing temperature of mullite was decreased to $850^{\circ}C$ for pH= 1.5∼2 and $1100^{\circ}C$ for pH= 8.5∼9. The grain size of the mullite synthesized at pH= 8.5∼9 was larger than that at pH= 1.5∼2 in overall heat-treated temperatures, showing smaller grain size in type II. Aspect ratio of the mullite grains was more increased at pH= 1.5∼2 than pH= 8.5∼9 in type I, showing similar aspect ratio at both pH conditions in type II. It was found that the synthesizing temperature and grain size were predominantly governed by the initial precursor pH and decomposition of the salt, with minor effect on the grain morphology.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.240-245
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• 2002

Cancer metastasis represents the most important cause of cancer death and antitumor agents that may inhibit this process have been extensively pursued. Invasion and metastasis of malignantly transformed cells involve degradation of the extracellular matrix (ECM) components by matrix metalloproteinases (MMP), especially MMP-2 and -9. We previously showed that H-ras-induced invasive phenotype may involve MMP-2, rather than MMP-9, in MCF10A cells. In the present study, we investigated the chemopreventive effect of Aster, a widely used culinary vegetable in Korea. We screened twelve extracts from three Aster species (Aster scaber, Aster oharai and Aster glehni) for the inhibitory effect on MMP activities of H-ras MCF10A human breast epithelial cells. All of the extracts tested in this study efficiently inhibited the gelatinolytic activities of MMP-2 and MMP-9. A more prominent inhibition was observed in MMP-2 activity compared to MMP-9. Out of twelve extracts, eight extracts showed>90％ inhibition of MMP-2 activity in H-ras MCF10A cells while only one extract showed>90％ inhibition of MMP-9 activity. We selected three extracts (AO-3, AG-3 and AS-EA) for further studies since they exerted a marked inhibition in the ratio of MMP-2 to MMP-9. Treatment with AO-3, AG-3 and AS-EA in H-ras MCF10A cells caused a significant inhibition of invasive phenotype and migration, proving a chemopreventive potential of these extracts. Taken together, our results demonstrate that extracts of Aster effectively inhibit invasion and migration of highly malignant human breast cells, possibly via downregulation of MMP-2 and MMP-9.

• BMB Reports
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• v.45 no.4
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• pp.247-252
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• 2012

Although previous studies have demonstrated that BMP9 is highly capable of inducing osteogenic differentiation of mesenchymal stem cells, the molecular mechanism involved remains to be fully elucidated. In this study, we showed that BMP9 simultaneously promotes the activation of Smad1/5/8, p38 and ERK1/2 in C3H10T1/2 cells. Knockdown of Smad4 with RNA interference reduced nuclear translocation of Smad1/5/8, and disrupted BMP9-induced osteogenic differentiation. BMP9-induced osteogenic differentiation was blocked by p38 inhibitor SB203580, whereas enhanced by ERK1/2 inhibitor PD98059. SB203580 decreased BMP9-activated Smads singling, and yet PD98059 stimulated Smads singling in C3H10T1/2 cells. The effects of inhibitor were reproduced with adenovirus expressing siRNA targeted p38 and ERK1/2, respectively. Taken together, our findings revealed that Smads, p38 and ERK1/2 are involved in BMP9-induced osteogenic differentiation. Also, it is noteworthy that p38 and ERK1/2 may play opposing regulatory roles in mediating BMP9-induced osteogenic differentiation of C3H10T1/2 cells.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.254-258
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• 2007

Several physicochemical properties including water solubility, vapor pressure, and hydrolysis of bistrifluron benzoylphenylurea insecticide developed in Korea, were measured based on OECD guidelines for testing of chemicals and Toxic Substances Control Act Test guidelines. Water solubility was low showing 30 ${\mu}g/l$ at $25^{\circ}C$ and in hydrolysis study, half-life at $20^{\circ}C$ was 10.9 days (pH 9.0) and was stable in pH 7.0 solution. At $40^{\circ}C$ hydrolysis rate was 20.6 days (pH 7.0) and 1.5 days (pH 9.0). The vapor pressure of bistrifluron was not obtained from vapor pressure experiments at $25^{\circ}C$ because the bistrifluron was not detected. Therefore, the vapor pressure was determined to be ${\leq}\;2.05{\times}10^{-8}$ torr which was calculated to apply the detection limit (50 ng) of bistrifluron. And this value is suggests it would not give environmental contamination by volatilization.

• Bulletin of the Korean Chemical Society
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• v.26 no.9
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• pp.1359-1365
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• 2005

A series of new chiral [iminophosphoranyl]ferrocenes, {${\eta}^5-C_5H_4-(PPh_2=N-2,6-R_2-C_6H_3)$}Fe{${\eta}^5-C_5H_3-1-PPh^2-2-CH(Me)NMe_2$} (1: R = Me, $^iPr$), {${\eta}^5{-C_5H_4-(PPh_2=N-2,6-R_2}^1-C_6H_3)$}Fe{${\eta}^5-C_5H_3-1-(PPh_2=N-2,6-R_2-C_6H_3)-2-CH(Me)R_2$} (2: $R^1\;=\;Me,\;^iPr;\;R^2\;=\;NMe_2$, OMe), and $({\eta}^5-C_5H_5)Fe${${\eta}^5-C_5H_4-1-PR_2-2-CH(Me)N=PPh_3$} (3:R = Ph, $C_6H_{11}$) have been prepared from the reaction of [1,1'-diphenylphosphino-2-(N,N-dimethylamino) ethyl]ferrocene with arylazides (1 & 2) and the reaction of phosphine dichlorides ($R_3PCl_{2}$) with [1,1'-diphenylphosphino-2-aminoethyl]ferrocene (3), respectively. They form palladium complexes of the type $[Pd(C_3H_5)(L)]BF_4$ (4-6: L = 1-3), where the ligand (L) adopts an ${\eta}^2-N,N\;(2)\;or\;{\eta}^2$-P,N (3) as expected. In the case of 1, a potential terdentate, an ${\eta}^2$-P,N mode is realized with the exclusion of the –=NAr group from the coordination sphere. Complexes 4-6 were employed as catalysts for allylic alkylation of 1,3-diphenylallyl acetate leading to an almost stoichiometric product yield with modest enantiomeric excess (up to 74% ee). Rh(I)-complexes incorporating 1-3 were also prepared in situ for allylic alkylation of cinnamyl acetate as a probe for both regio- and enantioselectivities of the reaction. The reaction exhibited high regiocontrol in favor of a linear achiral isomer regardless of the ligand employed.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.71-76
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• 1986

Bacillus thuringiensis var. thuringiensis H1 (BTT) strain was cultured in the 4 different fermentation media and then measured their growths and the productions of endotoxin crystals from the culture media. Out of the 4 media, the productions of the endotoxin crystals and spores were maximal in the pH9-M-3 medium. The wet weight of BTT cells grown in the 150ml culture was approximately 3.218g and the number of the viable spores was $3.3{\times}10^{10}/ml$, and the ratio of the endotoxin weight over total cell weight was 20.05%. The generation time of the BTT bacteria in the M-1 was about 47.6 minutes in the M-2, 132.9 minutes in the M-3 and 110.2 minutes in the M-4. The proper pH for the production of the endotoxin by BTT appeared to be pH 6.5.

• Korean Journal of Crystallography
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• v.3 no.1
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• pp.31-36
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• 1992

6, 9-Difluoro-11, 21-dihydroxyl-16, 17-[(1methylehtylidene)bis(oxy)]-pregna-1, 4-diene-3, 20-dione (fluorocinolone acetonide) , C24H3OF106, trigonal, R3 (defined as a hexagonal lattice), a =b = 17.896 k, c: 18.365 k, V=5094.3 A', Z=9, 1 (MoK a) =0.7107 A, D=1.31 g/cm3, D.: 1.328 g/cm3 T=298 K, final R=0.050 for 1101 unique observed reflections. The molecule has conformational features in common with other corticosteroids. Three molecules related by 3-fold symmetry are involved in hydrogen bonding, forming a layer of molecules perpendicular to the c-axis.

• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.28-32
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• 2008

Hydrogenated microcrystalline silicon(${\mu}c$-Si:H) films were prepared using inductively coupled plasma chemical vapor deposition(ICP-CVD) method, electrical and optical properties of these films were studied as a function of silane concentration. And then, effect of $PH_3\;and\;B_2H_6$ addition on their electrical properties was also investigated for solar cell application. Characterization of these films from X-ray diffraction revealed that the conductive film exists in microcrystalline phase embedded in an amorphous network. At $PH_3/SiH_4$ gas ratio of $0.9{\times}10^{-3}$, dark conductivity has a maximum value of ${\sim}18.5S/cm$ and optical bandgap also a maximum value of ${\sim}2.39eV$. Boron-doped ${\mu}c$-Si:H films, satisfied with p-layer of solar cell, could be obtained at ${\sim}10^{-2}\;of\;B_2H_6/SiH_4$.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1537-1539
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• 1997

In this study, the dielectric properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Ceramics have been investigated as a addition of the amount of $MnO_2(0{\leq}x{\leq}0.9wt%)$. The Temperature-dependant dielectric characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). The maximum dielectric permittivity decreased by substitution $MnO_2$ and the dielectric loss decreased with increasing $MnO_2$ substitution amount. It is expected decreasing in inner heat energy for temperature with increasing $MnO_2$ substitution.

• BMB Reports
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• v.48 no.7
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• pp.401-406
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• 2015

Here we report that the H3K9 demethylase KDM3B represses transcription of the angiogenesis regulatory gene, ANGPT1. Negative regulation of ANGPT1 by KDM3B is independent of its Jumonji (JmjC) domain-mediated H3K9 demethylase activity. We demonstrate that KDM3B downregulates ANGPT1 via interaction with SMRT, and suggest that the repressor complex is formed at the promoter area of ANGPT1. Using MTT and wound healing assays, depletion of KDM3B was found to increase cell proliferation and cell motility, indicating that KDM3B has a role in angiogenesis. [BMB Reports 2015; 48(7): 401-406]