• Electrical & Electronic Materials
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• v.6 no.3
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• pp.207-213
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• 1993

Pb(Z $r_{0.54}$, $Ti_{0.46}$) $O_{3}$에 B $i_{2}$ $O_{3}$를 0.0wt%까지 첨가하여 미세구조, 유전, 압전, 성질에 미치는 영향을 고찰하였다. B $i_{2}$ $O_{3}$의 고용범위는 약 0.5~0.7wt%정도 이었고 B $i_{2}$ $O_{3}$ 첨가량이 증가함에 따라서 결정립의 크기가 감소하였다. B $i_{2}$ $O_{3}$첨가량이 증가함에 따라 고용한계까지는 $d_{33}$ , tan .delta., .xi.$_{r}$(분극후)값이 증가하였으며 Qm값과 밀도는 감소하였다. $K_{p}$ 값은 B $i^{3+}$ 가 P $b^{2+}$를 치환하므로 형성되는 Pb공공의 형성에 의해 자발분극이 증가됨에 따라 증가하였다.다.

• Macromolecular Research
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• v.14 no.3
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• pp.373-382
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• 2006

A series of crosslinkable, waterborne polyurethanes (I-WBPUs) were prepared by in-situ polymerization using isophorone diisocyanate (IPDI)/poly(tetramethylene oxide) glycol (PTMG, $M_n$=2,000)/dimethylol propionic acid (DMPA)/ethylene diamine (EDA)/triethylamine (TEA)/aminoplast[hexakis(methoxymethyl)melamine (HMMM)] as a crosslinking agent. Typical crosslinkable, waterborne polyurethanes (B-WBPUs) blended from WBPU dispersion and aqueous HMMM solution was also prepared to compare with the I-WBPUs. The crosslinking reaction between WBPU and HMMM was verified using FTIR and XPS analysis. The effect of the HMMM contents on the dynamic mechanical thermal, thermal, mechanical, and adhesion properties of the I-WBPU and B-WBPU films were investigated. The storage modulus(E'), glass transition temperatures of the soft segment ($T_{gs}$) and the amorphous regions of higher order ($T_{gh}$), melting temperature ($T_m$), integral procedural decomposition temperature (IPDT), residual weight, $T_{10%}$ and $T_{50%}$ (the temperature where 10 and 50% weight loss occurred), tensile strength, initial modulus, hardness, and adhesive strength of both I-WBPU and B-WBPU systems increased with increasing HMMM content. However, these properties of the I-WBPU system were higher than those of the B-WBPU system at the same HMMM content. These results confirmed the in-situ polymerization used in this study to be a more effective method to improve the properties of the WBPU materials compared to the simple blending process.

• Communications of the Korean Mathematical Society
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• v.33 no.3
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• pp.889-899
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• 2018

In this paper, we present some upper bounds for unitarily invariant norms inequalities. Among other inequalities, we show some upper bounds for the Hilbert-Schmidt norm. In particular, we prove $${\parallel}f(A)Xg(B){\pm}g(B)Xf(A){\parallel}_2{\leq}{\Large{\parallel}}{\frac{(I+{\mid}A{\mid})X(I+{\mid}B{\mid})+(I+{\mid}B{\mid})X(I+{\mid}A{\mid})}{^dA^dB}}{\Large{\parallel}}_2$$, where A, B, $X{\in}{\mathbb{M}}_n$ such that A, B are Hermitian with ${\sigma}(A){\cup}{\sigma}(B){\subset}{\mathbb{D}}$ and f, g are analytic on the complex unit disk ${\mathbb{D}}$, g(0) = f(0) = 1, Re(f) > 0 and Re(g) > 0.

• Bulletin of the Korean Mathematical Society
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• v.51 no.2
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• pp.555-565
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• 2014

An ideal I of a ring R is strongly ${\pi}$-regular if for any $x{\in}I$ there exist $n{\in}\mathbb{N}$ and $y{\in}I$ such that $x^n=x^{n+1}y$. We prove that every strongly ${\pi}$-regular ideal of a ring is a B-ideal. An ideal I is periodic provided that for any $x{\in}I$ there exist two distinct m, $n{\in}\mathbb{N}$ such that $x^m=x^n$. Furthermore, we prove that an ideal I of a ring R is periodic if and only if I is strongly ${\pi}$-regular and for any $u{\in}U(I)$, $u^{-1}{\in}\mathbb{Z}[u]$.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.498-504
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• 2002

Purpose : The purpose of this study was to evaluate the perioperative myocardial damage in pediatric congenital heart disease with the cardiac specific protein of cardiac troponin I(cTpn-I). Methods : All 25 pediatric patients who were diagnosed with tetralogy of Fallot or double outlet right ventricle were classified as group A(acyanotic, $SaO_2$ >90%), group B(mildly cyanotic, $SaO_2$ >80-90%) and group C(moderately cyanotic, $SaO_2$ <80%). The control group D was consisted of 10 patients with ventricular septal defects who were operated in the same period. We measured preoperative hemoglobin, preoperative and postoperative(24 and 72 hour) arterial oxygen saturation, cTpn-I and creatine kinase(CK-MB). Results : Total 25 patients were subdivided into 6 of group A, 12 of group B and 7 of group C. The concentrations of preoperative cTpn-I were $0.23{\pm}0.12ng/mL$ in group A, $0.25{\pm}00.12 ng/mL$ in group B, $0.26{\pm}0.13ng/mL$ in group C. And the concentrations of cTpn-I in postoperative 24 hour were $10.04{\pm}5.28ng/mL$ in group A, $12.50{\pm}6.86ng/mL$ in group B, $12.55{\pm}9.90ng/mL$ in group C. Which revealed cTpn-I in group C was higher than that of the another less cyanotic groups. In addition, the concentration of cTpn-I of group C in postoperative 72 hour was higher than any other groups. The concentration of cTpn-I in postoperative 72 hour was statistically correlated with that in postoperative 24 hour and preoperative arterial oxygen saturation(P=0.001). Conclusion : Preoperative chronic cyanosis can influence on the postoperative concentration of cTpn-I in pediatric cardiac patients, which means impairment on the postoperative myocardial recovery.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.46-53
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• 2008

Background and Objectives : The aim of this study was to investigate the anti-oxidant, anti-allergic and anti-inflammatory ability of the Taglisodog-eum(SHE) extract on the RAW 264.7 and EL4 cells Materials and Methods : Three types of experiments were implemented for this study: first, the experiment to study the anti-oxidant effect of SHE using Riboflavin; second, in vitro experiment to investigate the inhibition of Th 2 cell differentiation by SHE using EL4 cells (IL-4 mRNA expression); third, the suppression of $NF-{\kappa}B$ activation using RAW 264.7 cells (iNOS and COX-2 mRNA expression). Results : The anti-oxidant ability of SHE were dose-dependantly increased. From in vitro, the LPS-induced iNOS and COX-2 mRNA expression were dose-dependantly decreased in the RAW264.7 cells treated with SHE and the PMA-induced IL-4 mRNA expression were also dose-dependantly decreased in EL4 cells. $NF-{\kappa}B$ activation was suppressed, and iNOS & COX-2 production were inhibited by SHE Conclusion : The results suggest that SHE has dose-dependant anti-oxidant ability, and has anti-allergic and anti-inflammatory effects through the suppression of $NF-{\kappa}B$ activation and the inhibition of Th 2 cell differentiation.

• Analytical Science and Technology
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• v.20 no.1
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• pp.10-16
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• 2007

This research was designed to investigate the formations of hazardous air pollutants in the MSWs pyrolysis-gasification-melting process. In this survey, PCDDs/PCDFs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) were investigated in the two facilities (A and B facilities). In A facility, the PCDDs/DFs concentrations were 0.88, 2.29, 0.16 ng I-TEQ/$m^3$ respectively on the secondary incinerator, boiler and stack. In B facility, the PCDDs/PCDFs concentrations were 0.22, 0.05 ng I-TEQ/$m^3$ respectively on the pyrolysis-gasification-melting furnace and stack. The concentrations of PCDDs/PCDFs increased due to resynthesis during cooling process in the both facilities. High concentrations of PCDDs/PCDFs isomers were founded as 2, 3, 4, 7, 8-PeCDF, 2, 3, 4, 6, 7, 8-HxCDF and 1, 2, 3, 6, 7, 8-HxCDF orderly in A facility, and 2, 3, 4, 7, 8-PeCDF, 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 6, 7, 8-HxCDF orderly in B facility.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.519-523
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• 2017

We investigated the applications of functional materials through the examination of a variety of physiological activities of Ipomoea aquatica extract. I. aquatica extract showed low cytotoxicity against murine melanoma B16F10 cells. At concentrations that exerted little or no cytotoxicity to the cells, I. aquatica extract showed high DPPH radical scavenging activity ($ID_{50}$, $7.84{\mu}g/mL$), inhibited tyrosinase activity ($ID_{50}$, $106.56{\mu}g/mL$), and decreased melanin content ($ID_{50}$, $41.75{\mu}g/mL$). The treatment of B16F10 cells with I. aquatica extract suppressed the protein expression of tyrosinase in a dose-dependent manner. These findings suggested that I. aquatica extract inhibited melanin synthesis in murine melanoma B16F10 cells through the suppression of intracellular tyrosinase expression, as well as the simultaneous direct inhibition of tyrosinase activity. Additionally, I. aquatica extract promoted the expression of involucrin, which is related to skin barrier protection. These results indicate that I. aquatica extract may be an appropriate material for the improvement of skin barrier function.

• Bulletin of the Korean Mathematical Society
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• v.23 no.2
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• pp.117-121
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• 1986

Connes [2] showed that if M is an injective .sigma.-finite factor of type II $I_{1}$ and $B_{\phi}$=C1 for some normal faithful state .phi. on M then M is isomorphic to the Araki-wood factor. In [7], Haagerup has succeeded to show that if M is an injective factor of type II $I_{1}$ with separable predual, then $B_{\phi}$=C1 for every normal faithful state on M. Since injective factors of type II $I_{\lambda}$, 0.leq..lambda.<1, were classified [9], this together classifies all injective factors of type III with separable predual. It is not known for non-injective case. In this paper we consider some conditions under which the bicentralizers be trivial.ivial.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.225-231
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• 2004

This study was designed to investigate the effect of Trolox, a hydrophilic analogue of vitamin E, on the alteration of vasoregulatory gene expression during hepatic ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia in vivo. The rats were treated intravenously with Trolox (2.5 mg/kg) or the vehicle as a control 5 min before reperfusion. Liver samples were obtained 5 h after reperfusion for a RT-PCR analysis on the mRNA for the genes of interest. These mRNA peptides are endothelin-1 (ET -1), potent vasoconstrictor peptide, its receptor $ET_A$ and $ET_B$, vasodilator endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), heme oxygenase-1 (HO-1), tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and cyclooxygenase-2 (COX-2). It was seen that serum alanine aminotransferase and lipid peroxi-dation levels were markedly increased after I/R and Trolox significantly suppressed this increase. In contrast, the glutathione concentration decreased in the I/R group, and this decrease was inhibited by Trolox. ET-1 mRNA expression was increased by I/R, an increase which was prevented by Trolox. The mRNA levels for $ET_A$ receptor was significantly decreased, whereas ET$_{B}$ receptor transcript increased in the I/R group. The increase in $ET_A$ was prevented by Trolox. The mRNA levels for iNOS and HO-1 significantly increased in the I/R group and Trolox attenuated this increase. There were no significant differences in eNOS mRNA expression among any of the experimental groups. The mRNA levels for COX-2 and TNF-$\alpha$ significantly increased in I/R group and Trolox also attenuated this increase. Our findings suggest that I/R induces an imbalanced hepatic vasoregulatory gene expression and Trolox ameliorates this change through its free radical scavenging activity.y.