• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1230-1231
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• 2008

The effect of content of $Al_2O_3+Y_2O_3$ sintering additives on the densification behavior, mechanical and electrical properties of the pressureless-sintered $SiC-ZrB_2$ electroconductive ceramic composites was investigated. The $SiC-ZrB_2$ electroconductive ceramic composites were pressureless-sintered for 2 hours at 1,700[$^{\circ}C$] temperatures with an addition of $Al_2O_3+Y_2O_3$(6:4 mixture of $Al_2O_3$ and $Y_2O_3$) as a sintering aid in the range of 8${\sim}$20[wt%]. Phase analysis of $SiC-ZrB_2$ composites by XRD revealed mostly of ${\alpha}$-SiC(6H), $ZrB_2$ and In Situ YAG($Al_5Y_3O_{12}$). The relative density, flexural strength, Young's modulus and vicker's hardness showed the highest value of 89.01[%], 81.58[Mpa], 31.437[GPa] and 1.34[GPa] for $SiC-ZrB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature respectively. Abnormal grain growth takes place during phase transformation from ${\beta}$-SiC into ${\alpha}$-SiC was correlated with In Situ YAG phase by reaction between $Al_2O_3$ and $Y_2O_3$ additive during sintering. Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of SiC-based electroconductive ceramic composites. In this paper, it is convinced that ${\beta}$-SiC based electroconductive ceramic composites for heaters or ignitors can be manufactured by pressureless sintering.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.82.1-82.1
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• 2003

The protective adaptive response to electrophiles and reactive oxygen species is mediated by enhanced expression of phase II detoxifying genes including glutathione S-transferases. ${\alpha}$-Lipoic acid, which exerts prooxidant or antioxidant activities, has been shown to activate the insulin signaling pathway and thus to induce insulin-like actions via PI3-kinase and Akt. Our previous studies have shown that PI3-kinase plays an essential role in Nrf2-or C/EBP${\beta}$-mediated glutathione S-transferase A2 (GSTA2) induction. (omitted)

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.312-316
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• 1996

A series of N-Cbz${alpha}$-aminosucinimides (1), combining common moieties of various anticonvulsants such as N-CO-C-N and cyclic imide in a single molecule, were synthesized from the corresponding (R)- and (S)-N-Cbz-aspartic acid (2). And their in vivo anticonvulsant evaluations in MES and PTZ test were investigated. And also the rotorod test for neurotoxicity was investigated. All the tested compounds (1), except 1c and 1f, showed significant anticonvulsant activities in both MES and PTZ test. And the most active compound among them in MES test was (R)-N-Cbz-${alpha}$-amino-N-methylsuccinimide (1b) $(ED_50/=52.5 mg/kg)$ and (S)-N-Cbz-aminosuccinimide((1d) was most active in PTZ test $(ED_50/=78.1 mg/kg)$. And the $TD_50$ values of the tested compounds were above 117.5 mg/kg. These pharmacological data were comparable to those of currently available anticonvulsants. And also we found that the pharmacological effects were dependent on their N-substituted alkyl chains and their stereochemistry.

• Journal of the Korean Magnetics Society
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• v.1 no.1
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• pp.12-16
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• 1991

The effect of annealing on the magnetic properties and the microstructures of the amorphous $Fe_{76-x}Cu_1Mo_xSi_{14}B_9$(x=2,3) alloys were investigated. When annealed at 500${^{\circ}C}$ for 1hr, $8{\sim}9{\times}10^3$ of the effective permeability and 3~4 A/m of the coercive force were achieved upon crystallization to $\alpha$-Fe phase. And the average diameter of the $\alpha$-Fe grains was about 20nm. For the nanovrystalline ferromagnets. the fine grain size is the important requirement to obtain a good soft magnetic property. In this work, in order to get the finer grain size of $\alpha$-Fe phase, two-step annealing treatment was given. That is, following the low-temperature at $400{^{\circ}C}$ for 1~3hr, the high-temperature annealing at $500{^{\circ}C}$ for 1hr was carried out. As the low-temperature annealing time increased, the effective permeability increased to $1.2{\sim}1.7{\times}10^4$ and the coercive force decreased to about 2 A/m. And the grain size was observed to be smaller than 10nm. The increased permeability and the decreased coercive force were attributed to the reduced average crystalline anisotropy by the refinement of $\alpha$-Fe(Si) grains.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.612-616
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• 2006

The protective effect of water extract of ash tree leaves (ALE) against oxidative damages was investigated in paracetamol-induced BALB/c mice. Biochemical analysis of anti-oxidative enzymes, immunoblot analyses of hepatic cytochrome P450 2El (CYP2E1), and the gene expression of tumor necrosis factor (TNF-${\alpha}$) were examined to determine the extract's protective effect and its possible mechanisms. BALB/c mice were divided into three groups: normal, paracetamol-administered, and ALE-pretreated groups. A single dose of paracetamol led to a marked increase in lipid peroxidation as measured by malondialdehyde (MDA). This was associated with a significant reduction in the hepatic antioxidant system, e.g., glutathione (GSH). Paracetamol administration also significantly elevated the expression of CYP2E1, according to immunoblot analysis, and of TNF-${\alpha}$ mRNA in liver. However, ALE pretreatment prior to the administration of paracetamol significantly decreased hepatic MDA levels. ALE restored hepatic glutathione and catalase levels and suppressed the expression of CYP2E1 and TNF-${\alpha}$ observed in inflammatory tissues. Moreover, ALE restored mitochondrial ATP content depleted by the drug administration. These results show that the extract of ash tree leaves protects against paracetamol-induced oxidative damages by blocking oxidative stress and CYP2E1-mediated paracetamol bioactivation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.3
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• pp.143-154
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• 2013

Purpose: This study was to find efficacy of integrin alpha2 (${\alpha}_2$) and epidermal growth factor receptor (EGFR) as tumor marker of oral squamous cell carcinoma (SCC) and clarify the selective cell death effect of anti-integrin ${\alpha}_2$ and anti-EGFR on SCC cells, additionally testify conjugated gold nanoparticles (GNP) with air plasma for selective cell death of oral SCC. Methods: Expression of integrin ${\alpha}_2$, EGFR on human SCC cells (SCC25) were examined by western blot. SCC25 cells were treated with anti-integrin ${\alpha}_2$, anti-EGFR and analysed by Hemacolor staining, immunoflorescence staining, FACS flow cytometry. Conjugated GNP with integrin ${\alpha}_2$, EGFR antibody were treated by air plasma on SCC cells. Results: Integrin ${\alpha}_2$ and EGFR were over-expressed on SCC25 cells than normal lung WI-38 cells. The cell viability rate of SCC25 cells treated with anti-integrin ${\alpha}_2$, anti-EGFR was lower than WI-38 cells. The concentration changes of nucleus, releasing cytochrome c and apoptosis inducing factor (AIF) from mitochondria to cytosol were observed. The changes of proteins related with apoptosis were observed. Increase of bax, bcl-xL, activation of caspase-3, -7, -9, and fragmentation of PARP, DFF45 and decrease of lamin A/C in SCC25 cells were observed. In FACS, increase of sub-$G_1$ and S phase was observed. Cell cycle related proteins, Such as cyclin D1, cyclin dependent kinase (CDK) 4, cyclin A, cyclin E, CDK 2, p27 were decreased. After SCC25 cells treated with conjugatged GNP-Integrin ${\alpha}_2$, GNP-EGFR, additionally air plasma, the cell death rate was significantly increased. Conclusion: Integrin ${\alpha}_2$, EGFR were over-expressed in oral SCC cells. Anti-integrin ${\alpha}_2$, anti-EGFR in SCC25 cells induced apoptosis selectively. When GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR were treated with air plasma on SCC25 cells, cancer cells were died more selectively. GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR with air plasma could be treatment choice of oral SCC.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.650-655
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• 2011

Three new peptide analogs 5a-c were obtained through coupling of 5-Amino benzimidazoles 2a-c with L-phenylalanine. For the purpose ${\alpha}$-amino group was blocked with phthalic anhydride and activation of ${\alpha}$-carboxy group of phenylalanine was carried out by preparing phthaloyl-L-phenylalanyl chloride 4. After developing a successful peptide linkage, the phthaloyl group was removed by treating 5a-c with hydrazine hydrate to get free peptides 6a-c, purified through a column of Amberlite (IR-4B). All of these compounds 2a-c and 5,6a-c have been characterized on the basis of their IR, 1H NMR and EIMS analyses. Antibacterial activity of these compounds is also been reported.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.13-30
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• 2010

Let C be a nonempty closed convex subset of a real Hilbert space H. Consider the following iterative algorithm given by $x_0\;{\in}\;C$ arbitrarily chosen, $x_{n+1}\;=\;{\alpha}_n{\gamma}f(W_nx_n)+{\beta}_nx_n+((1-{\beta}_n)I-{\alpha}_nA)W_nP_C(I-s_nB)x_n$, ${\forall}_n\;{\geq}\;0$, where $\gamma$ > 0, B : C $\rightarrow$ H is a $\beta$-inverse-strongly monotone mapping, f is a contraction of H into itself with a coefficient $\alpha$ (0 < $\alpha$ < 1), $P_C$ is a projection of H onto C, A is a strongly positive linear bounded operator on H and $W_n$ is the W-mapping generated by a finite family of nonexpansive mappings $T_1$, $T_2$, ${\ldots}$, $T_N$ and {$\lambda_{n,1}$}, {$\lambda_{n,2}$}, ${\ldots}$, {$\lambda_{n,N}$}. Nonexpansivity of each $T_i$ ensures the nonexpansivity of $W_n$. We prove that the sequence {$x_n$} generated by the above iterative algorithm converges strongly to a common fixed point $q\;{\in}\;F$ := $\bigcap^N_{i=1}F(T_i)\;\bigcap\;VI(C,\;B)$ which solves the variational inequality $\langle({\gamma}f\;-\;A)q,\;p\;-\;q{\rangle}\;{\leq}\;0$ for all $p\;{\in}\;F$. Using this result, we consider the problem of finding a common fixed point of a finite family of nonexpansive mappings and a strictly pseudocontractive mapping and the problem of finding a common element of the set of common fixed points of a finite family of nonexpansive mappings and the set of zeros of an inverse-strongly monotone mapping. The results obtained in this paper extend and improve the several recent results in this area.

• Journal of Dairy Science and Biotechnology
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• v.25 no.2
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• pp.11-16
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• 2007

The nomenclature of genetic variants of casein which is major protein in milk have had a lot of confusion, but now have established. Genetic variants of ${\alpha}_{s1}-CN,\;{\alpha}_{s2}-CN,\;{\beta}-CN,\;{\kappa}-CN$ have reported 8 variants(A, B, C, D, E, F, G, H), 4 variants(A, B, C, D), 13 variants ($A_1,\;A_2,\;A_3,\;A_4$, B, C, D, E, F, G, $H_1,\;H_2$, I), 11 variants(A, B, C, E, $F_1,\;F_2,\;G_1,\;G_2$, H, I, J), respectively. Their data detailed have introduced in several web sites including www.uniprot.org. The studies on genetic variants of casein from Korean native cattle have been reported only ${\beta}-casein\;A_4$ but still not established the protein sequence. The classification and distinct nomenclature of genetic variants of bovine casein were required because the development of milk science and technology have been focused in the region that have to studied biochemically such as functional foods, EMC and GMO et al.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.177-182
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• 2006

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.