• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.391-398
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• 2006

$NF-{\kappa}B$ is a transcription factor involved in the innate immunity against bacterial infection and inflammation. It is also known to render cells resistant to the apoptosis caused by some anticancer drugs. Such a chemoresistance of cancer cells may be related to the activation of $NF-{\kappa}B$ transcription factor; however, the mechanism of activation is not well understood. Here, we demonstrate that a chemotherapeutic agent, etoposide, independently stimulates the $I{\kappa}B{\alpha}$ degradation pathway and PI3-kinase/Akt signaling pathway: The classical $I{\kappa}B{\alpha}$ degradation pathway leads to the nuclear translocation and DNA binding of p65 subunit through $IKK{\beta}$ kinase, whereas the PI3-kinase/Akt pathway plays a distinct role in activating this transcription factor. The PI3-kinase/Akt pathway acts on the p50 subunit of the $NF-{\kappa}B$ transcription factor and enhances the DNA binding affinity of the p50 protein. It may also explain the role of the PI3-kinase/Akt pathway in the anti-apoptotic function of $NF-{\kappa}B$ during chemoresistance of cancer cells.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.449-456
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• 2012

Herein, we design a wideband $8{\times}8$ waveguide Butler matrix in order to use in a multi-port amplifiers(MPAs) at Ka-band. To achieve the broadband characteristic, we design a binomial 6-slot 3 dB directional coupler which is used to configure the $8{\times}8$ Butler matrix. The measured results of the fabricated $8{\times}8$ Butler matrix have low insertion loss of less than 0.3 dB, good return loss of over 26 dB and high isolation of over 35 dB within the design bandwidth of 3 GHz.

• Journal of the Korean Ceramic Society
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• v.50 no.1
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• pp.57-62
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• 2013

We investigated the thermal and electrical properties of the $B_2O_3-ZnO-Bi_2O_3$ glass system as a sealing material in sheath heater modules. A composition with over 90 wt% $Bi_2O_3$ in the $B_2O_3-ZnO-Bi_2O_3$ system was glassified by controlling the cooling rate. The glass transition temperature and thermal expansion coefficient in bismate glass could be controlled by the minor ingredients of ZnO, $SiO_2$, $BaO_2$, and $K_2O$. The $B_2O_3-ZnO-Bi_2O_3$ glass system bonded well to metal, and bismate glass insulating properties were comparable to those of bismate glass $B_2O_3-ZnO-PbO$ glass system in a sheath heater module.

• Journal of the Korean Ceramic Society
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• v.35 no.3
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• pp.287-293
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• 1998

The effects of B2O3 addition on the sintering behavior and th microwave dielectric properties of $(Mg_{0.93}Ca_{0.07})TiO_3$ ceramics were investigated. By addition of $B_2O_3$, increases the density of the ceramics increases and grain growth enhances, It was densified to over 94% of $(Mg_{0.93}Ca_{0.07})TiO_3$ theoretical density by the addition of 0.15-1.0wt% B2O3 and stable microwave dielectric properties observed by the addition of 0.2-0.4wt% $B_2O_3.\;(Mg_{0.93}Ca_{0.07})TiO_3$ ceramics sintered at $1200^{\circ}C$ exhibits maximum dielectric constants of 24-25 quality factor($Q{\times}f$) of more than 70000 and temperature coefficient of resonant frequency of $0\;ppm/^{\circ}C$ by adding of 0.15-0.4wt% $B_2O_3$.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.54-59
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• 2007

A sintering aid, $B_{2}O_{3}$ have been included into a $LiAlO_{2}$ electrolyte support by a tape casting method in order to reinforce mechanical strength of the support for molten carbonate fuel cells [MCFCs). Starting idea originates from the low melting point of $B_{2}O_{3}$ ($450^{\circ}C$), which can provide the low temperature consolidation of ceramic materials. The mechanical properties and the microstructure changes of the $B_{2}O_{3}$-included electrolyte support were examined by scanning electron microscope, mercury porosimetry, X-ray powder diffraction [XRD], high temperature differential scanning calorimeter and three-point bending strength measurement. The mechanical strength was clearly improved by addition of $B_{2}O_{3}$. The increase of mechanical strength results from the neck growth of a new $LiAlO_{2}$ phase between $LiAlO_{2}$ particles by the liquid phase sintering. Average pore size and porosity of the electrolyte support reinforced by addition of the sintering aid, $B_{2}O_{3}$, was $0.24{\mu}m$ and 59%, respectively which were suitable microstructure of a matrix for an application of MCFCs.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.291-296
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• 1997

The studies were carried out to evaluate the constituents in the aerial part of Isodon excisus var. coreanus (Labiatae). From the aqueous fraction of methanol extract, compound I (${\alpha}$-[[3-(3, 4-dihydroxyphenyl)-1-oxo-2-propenyl]oxy]-3,4-dihydroxy-benzenepropanoic acid), compound II (9-methyl-dihydroferulic acid-4-O-.betha.-D-glucopyranosyl $(1{\rightarrow}2)$-${\alpha}$-L- rhamnopyranosyl (1.rarw.4)-.betha.-D-glucopyranoside), compound III (ent-7.alpha., 11${\alpha}$,15.betha.-trihydroxy-kaur-16-en-1-O-.betha.-D-glucopyranoside) and compound IV ($2{\alpha}$,3${\beta}$,$7{\alpha}$,23-tetrahydroxy-olean-12 -en-28-oic acid 28-O-${\beta}$-D-glucopyranoside) were isolated and identified on the basis of their physicochemical and spectroscopic evidences[IR, FAB(-)MS,$^{1}H-NMR,$$^{13}C-NMR,$$ HMQC$$^{1}H-^{1}H $COSY and HMBC (Heteronuclear Multiple Bond Connectivity)]. Especially, New compounds II and III were named Isodonin A and Isodonin B respectively.

• YAKHAK HOEJI
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• v.50 no.6
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• pp.403-408
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• 2006

1-Amino-5,6-dimethoxyindan hydrochloride was synthesized from 3- (3,4-dirnethoxyphenyl)propionic acid by intramolecular Friedel-Crafts acylation, oximation with hydroxylamine, and reduction with an overall yield of 74%. 2-Amino-5,6-dimethoxyindan hydrochloride was synthesized from 3-(3,4-dirnethoxyphenyl)propionic acid by intramolecular Friedel-Crafts acylation, oximation with isoamylnitrite, reduction in NaOH and reaction with HCI to form 5,6-dimethoxy-2-indanone, which was reacted with hydroxylamine and reduced with an overall yield of 42%. 5,6-Dimethoxyindan-1,2-dione-2-oxime, which was catalytically hydrogenated to afford cis-, and trans-1-amino-5,6-dimethoxyindan-1-ol as 3 : 1 ratio. This mixture was treated with Li and reacted with chloroacetyl chloride. Cis isomer was acylated and cyclized to synthesize rir -( ${\pm}$ )-7,8-dimethoxy-4,4a,5,9b-tetrahydroindeno[1,2-b][1,4]oxazin-3(2H)-one, but trans isomer was just acylated to form amide.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.6
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• pp.1-7
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• 1998

In this paper, SMD type backward wave 3dB coupler for PCS basestation application was designed, fabricated and measured. We designed that it could be replaced for commercial basestation system and it was 0.56 $\times$ 0.35 inches size. The test results show that coupler is well operated within frequency range of 1.75 ~ 1.98GHz, which is defined on PCS system. The coupler reveals insertion loss 0.295dB, isolation -30.31dB, amplitude balance 0.05dB, phase balance 0.02$^{\circ}$, input and output impedance matching -30.38dB, -39.72dB, respectively.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.63-71
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• 2005

Equilibrium geometries, electronic structures, and energies of borocarbon clusters (binary compounds of carbon and boron), an unexplored class of molecules with highly unusual characteristics and potential for further development, have been investigated by means of B3LYP/6-311+G$^*$ density functional theory computations. A large number of B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ clusters with planar and non-planar monocyclic and polycyclic rings, as well as cage structures, have been systematically studied. Unexpectedly, planar forms are predicted not only to be the most stable structures, but also, in many cases, to have unprecedented planar heptacoordinate boron (p-heptaB) and planar heptacoordinate carbon (p-heptaC) arrangements. All these pheptaB and p-heptaC have 6π electrons and are aromatic according to the nucleus independent chemical shift (NICS). This novel bonding pattern is analyzed in terms of natural bond orbital (NBO) analysis. For virtually all possible B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ combinations, the p-heptaB arrangements are the more stable than other type structures.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.426-432
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• 2001

Vitamin B(sub)12(cobalamin) is an essential nutrient in human and it is particularly important during pregnancy. Nevertheless very few studies have reported, concerning vitamin B(sub)12 in relation with reproduction. This study was conducted to evaluate the vitamin B(sub)12 nutrition status of Korean pregnant women and to investigate the relationship between serum vitamin B(sub)12 levels of maternal-umbilical cord blood and pregnancy outcomes. Dietary vitamin B(sub)12 intakes of the pregnants were estimated by semiquantitative frequency questionnaire. Serum vitamin B(sub)12 levels in both maternal blood and umbilical cord blood of 30 pregnant women at delivery were measured by radioimmunoassay. Mean vitamin B(sub)12 intake was 3.3$\pm$1.4$\mu\textrm{g}$/d which was 125.8% of the Korean RDA(2.6$\mu\textrm{g}$) for vitamin B(sub)12 level of umbilical cord blood was 607.8$\pm$282.9pg/ml, more than two fold of maternal vitamin B(sub)12 level 268.6$\pm$97.8pg/ml. This finding indicates that fetal uptake of vitamin B(sub)12 in the fetus may be due to an active transport mchanism across the placenta. Umbilical cord blood vitamin B(sub)12 levels were highly correlated with maternal levels($r^2$=0.548, p<0.001), showing that fetal vitamin B(sub)12 level is affected by maternal status. However there was no significant correlation between the serum vitamin B(sub)12 levels in maternal-umbilical cord blood and the pregnancy outcomes except for the birth weight. Maternal-umbilical serum vitamin B(sub)12 levels were the highest in the group of birth weight 3.0-3.5kg, and the lowest in the group of birthweight below 3.0kg. (Korean J Nutrition 34(4) : 426~432, 2001)