• Journal of the Korean Chemical Society
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• v.28 no.4
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• pp.210-216
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• 1984

Solvatochromic comparison methods were applied to determine Taft's solvent parameters, ${\pi}^{\ast}$(solvent polarity-polarizability), ${\alpha}$(solvent hydrogen bond donor acidity) and ${\beta}$ (solvent hydrogen bond acceptor basicity) for MeOH-MeCN solvent mixtures. Swain's solvent parameters A(anion solvation scale) and B(cation solvation scale) were also determined by least square fitting of kinetic data in the same binary solvent mixtures. It was found that: (i)${\beta}$ depends on the basicity of the solvent and increases with the MeOH content owing to the increase in polymeric structure of methanol; (ii) ${\pi}^{\ast}$depends on the dipole moment of the solvent and increases with the MeCN content of the solvent; (iii) ${\alpha}$ increases rapidly with the MeOH content as the hydrogen bond donor acidity of the solvent mixtures increases. Taft's reaction constants a and s and Swain's reaction constants a and b were determined for the reactions reported from our laboratory previously using solvent parameters determined in this work. No meaningful inter-relationship was found between the two set of reaction parameters, but a good linear correlation was found between the ratios a/s and a/b. Solvent effect on the reaction mechanism, substituent effect and leaving group ability were examined in the light of these reaction constants ratios.

• Macromolecular Research
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• v.13 no.6
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• pp.529-532
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• 2005

A novel amphiphilic, symmetric rod-coil, triblock copolymer (denoted as PHEMA-b-PF-b-PHEMA) of poly(9,9-didodecylfluorene-2,7-diyl) (PF) and poly(hydroxyl ethyl methacrylate) (PHEMA) was synthesized. A $\pi$-conjugated poly(9,9-didodecylfluorene-2,7-diyl) (PF) was used as a rodlike midblock segment and connected with hydrophilic end blocks of poly(hydroxyl ethyl methacrylate) (PHEMA) by using an ATRP technique. The chemical structure of PHEMA-b-PF-b-PHEMA was confirmed by $^{1}H$-NMR and GPC, and its PL properties were investigated in selected solvents. Due to the dissimilarities in molecular conformation and solubility between PHEMA and PF blocks, both block segments were segregated to display a phase-separated morphology on a Si wafer.

• BMB Reports
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• v.40 no.6
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• pp.845-852
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• 2007

The highly evolved flowers of orchids have colorful sepals and fused columns that offer an opportunity to discover new genes involved in floral development in monocotyledon species. In this investigation, we cloned and characterized the homologous PISTALLATA-like (PI-like) gene PhPI15 ($\underline{Ph}alaenopsis$ $\underline{PI}$ STILLATA # $\underline{15}$), from the Phalaenopsis hybrid cultivar. The protein sequence encoded by PhPI15 contains a typical PI-motif. Its sequence also formed a subclade with other monocot PI-type genes in phylogenetic analysis. Southern analysis showed that PhPI15 was present in the Phalaenopsis orchid genome as a single copy. Furthermore, it was expressed in all the whorls of the Phalaenopsis flower, while no expression was detected in vegetative organs. The flowers of transgenic tobacco plants ectopically expressing PhPI15 showed male-sterile phenotypes. Thus, as a Class-B MADS-box gene, PhPI15 specifies floral organ identity in orchids.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1875-1880
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• 2010

A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-($\alpha$-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffraction. Density function theory (DFT) calculations were performed by using B3LYP method with 6-$311G^{**}$ basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-$311G^{**}$ method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-$311G^{**}$ method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n $\rightarrow\pi^*$ and $\pi\rightarrow\pi^*$ transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been calculated, revealing the correlations between $C^0_{p,m}$, $S^0_m$, $H^0_m$ and temperature.

• Biomedical Science Letters
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• v.20 no.4
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• pp.244-249
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• 2014

Arazyme is a metalloprotease secreted by Aranicola proteolyticus that was previously shown to suppress cytokine expression of keratinocytes and endothelial cells and inhibit histopathological features in an atopic dermatitis-like animal model. However, the regulatory effects of arazyme in other allergic diseases have yet to be elucidated. In this study, we investigated whether arazyme is effective against neutrophil apoptosis in allergic diseases such as allergic rhinitis and asthma. Arazyme inhibited neutrophil apoptosis of normal subjects in a dose-dependent manner. However, the antiapoptotic effect of arazyme was reversed by LY294002, an inhibitor of PI3K, AKTi, an inhibitor of Akt, PD98059, an inhibitor of MEK, and BAY-11-7085, an inhibitor of NF-${\kappa}B$. Arazyme induced activation of NF-${\kappa}B$ via PI3K/Akt/ERK pathway. The anti-apoptotic effect of arazyme is associated with inhibition of cleavage of caspase 3 and caspase 9. Arazyme inhibited constitutive apoptosis of neutrophil in a dose-dependent manner in allergic subjects, and its mechanism was shown to be associated with PI3K/Akt/ERK/NF-${\kappa}B$. The results presented here improve our understanding of neutrophil apoptosis regulation and will facilitate development of drugs for treatment of allergic diseases.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.288-296
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• 2022

This study aimed to verify the effect of Citrus unshiu peel water extract (CUP) on a mouse model of acute gastritis (AG) induced by HCl/ethanol. Several studies have found that CUP has anti-inflammatory effects. The AG model was induced by oral administration of 150 mM HCl/60% ethanol (550 µL) to all groups except the control group. Also, for drug treatment, sucralfate (10 mg/kg) and CUP (100 or 200 mg/kg) were orally administered for 90 minutes before induction. The effect of CUP treatment was confirmed by gross gastric mucosal damage measurement, and the levels of Glutamic Oxaloacetic Transaminase (GOT), Glutamic Pyruvic Transaminase (GPT), and myeloperoxidase were reduced as well as the levels of oxidative stress biomarkers and their related proteins. In addition, the levels of inflammatory proteins, mediators, and cytokines were significantly downregulated byPI3K/Akt signaling. Taken together, these results show that CUP treatment alleviates AG by regulating PI3K/Akt signaling.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.8
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• pp.888-892
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• 2004

It is necessary to develop soft magnetic layer with high saturation magnetization 4 $\pi{M}_s$ and in-plane magnetic anisotropy field Hk for soft magnetic underlayer of perpendicular magnetic recording media with high signal to noise ratio. Fe-Co-B layer with high 4 $\pi$Ms of about 23 kG deposited on Ni-Fe and Ni-Fe/Si seedlayer exhibited very high in-plane magnetic anisotropy filed Hk of about 280 and 380 Oe, respectively, In-plane XRD studies clarified that the lattice spacing of planes along the easy axis direction was longer than that along the hard axis direction in the Fe-Co-B layers with high Hk. These results indicate that high Hk of Fe-Co-B/Ni-Fe and Fe-Co-B/［Ni-Fe/si］ layers were resulted from magnetoelastic anisotropy owing to a residual stress. Moreover, the high Hk in the Fe-Co-B/Ni-Fe layer was maintained until 30$0^{\circ}C$ annealing temperature.

• Kyungpook Mathematical Journal
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• v.28 no.2
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• pp.129-139
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• 1988

Let $T^{\alpha}_{\lambda}$(p, A, B) denote the class of functions $$f(z)=z^p-{\sum\limits^{\infty}_{k=1}}{\mid}a_{p+k}{\mid}z^{p+k}$$ which are regular and p valent in the unit disc U = {z: |z| <1} and satisfying the condition $\left|{\frac{{e^{ia}}\{{\frac{f^{\prime}(z)}{z^{p-1}}-p}\}}{(A-B){\lambda}p{\cos}{\alpha}-Be^{i{\alpha}}\{\frac{f^{\prime}(z)}{z^{p-1}}-p\}}}\right|$<1, $z{\in}U$, where 0<${\lambda}{\leq}1$, $-\frac{\pi}{2}$<${\alpha}$<$\frac{\pi}{2}$, $-1{\leq}A$<$B{\leq}1$, 0<$B{\leq}1$ and $p{\in}N=\{1,2,3,{\cdots}\}$. In this paper, we obtain sharp results concerning coefficient estimates, distortion theorem and radius of convexity for the class $T^{\alpha}_{\lambda}$(p, A, B). It is further shown that the class $T^{\alpha}_{\lambda}$(p, A, B) is closed under "arithmetic mean" and "convex linear combinations". We also obtain class preserving integral operators of the form $F(z)=\frac{p+c}{z^c}{\int^z_0t^{c-1}}f(t)dt$, c>-p, for the class $T^{\alpha}_{\lambda}$(p, A, B). Conversely when $F(z){\in}T^{\alpha}_{\lambda}$(p, A, B), radius of p valence of f(z) has also determined.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.447-451
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• 2021

In this study, we discovered for the first time that linarin, a flavonoid compound, enhances melanin biosynthesis in B16F10 cells, and subsequently elucidated the underlying mechanism of linarin-induced melanogenesis. Linarin showed no cytotoxicity at a concentration of 42 μM and significantly increased intracellular tyrosinase activity and melanin content in B16F10 cells. Mechanistic analysis showed that linarin increased the expression of tyrosinase, tyrosinase-related protein 1 (TRP-1), and microphthalmia-associated transcription factor (MITF) that are related to melanogenesis. Moreover, linarin decreased the phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT). Finally, we evaluated the effect of the structure-activity relationship of linarin and its aglycone on melanogenesis. The results indicated that linarin enhances the expression of melanogenic proteins by activating MITF expression via the modulation of mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K), and protein kinase B signaling pathways in B16F10 cells, thereby enhancing melanogenesis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.721-726
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• 2003

This paper present a waveguide slot 16${\times}$16 assay antenna with diaphragms for 38 GHz frequency band. Diaphragms are used to control the impedance and to minimize the return loss of the structure. A 20 dB Chebyshev array of 16 waveguide slots has been designed by optimizing the positions and sizes of the diaphragms. A serial feeding system with $\pi$- and T-junction power dividers has also designed to get a 20 dB Chebyshev power distribution. A 16${\times}$16 slot array was designed for a Fixed Wireless Access System at 38 GHz frequency band, manufactured using a computer controlled milling technique, and measured for the return -19 dB and the frequency band of 740 MHz.