• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1281-1283
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• 2003

Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. These stack of glass slide with planar lipid bilayers are not well fit for commercial solid-state NMR probe with round coil. Therefore, homebuilt solid-state NMR probe was built and used for a stack of thin glass plates and RF coil is wrapping directly around the flat square sample. The overall filling factor of the coil is much better and the large surface area enhances the extent to orientation by providing uniform environments for the phospholipids and the high ratio of circumference to area reduces edge effects. $^1H\;and\;^{15}N$ double resonance probe for 400 MHz NMR (9.4T) with a flat coil (coil size: 11 mm ${\times}$ 20 mm ${\times}$ 4 mm) is constructed and tested.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.93-97
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• 1991

Rate constants have been measured spectrophotometrically for the reactions of alkali metal ethoxides with 4-nitrophenyl benzoate, S-4-nitrophenyl thiobenzoate and 4-nitrophenyl thionbenzoate in ethanol at 25$^{\circ}$C. Substitution of S for O in the leaving group has not affected reactivity significantly, while the effect of the similar replacement in the acyl group has led to rate decrease by a factor of 10, although pronounced rate enhancements have been expected for both systems. The replacement of O by a polarizable S has also influenced the reactivity of the esters toward alkali metal ethoxides, i.e. the reactivity decreases as the size of the metal ion decreases. The alkali metal ions have showed inhibition effect instead of catalytic effect which would have been expected for the present system. The effect of replaced sulfur atom on the reactivity for the present system is attributed to the nature of hard and soft acids and bases.

• Bulletin of the Korean Chemical Society
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• v.13 no.2
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• pp.122-127
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• 1992

Some perovskites $A($Cu_{1}3}Nb_{2}3}$)O_3(A=$Sr^{2+}$$, $Ba^{2+}$ and $Pb^{2+}$) and their series of mixed perovskites have been prepared by solid state reaction. Single perovskite phase was obtained in Sr or Ba rich samples, but pyrochlore phase was found in Pb rich samples. The stability of perovskite phase is dependent on the ionicity of bonding as well as the tolerance factor. All the obtained perovskites have tetragonal symmetry distorted by Jahn-Teller effect of $Cu^{2+}$. In the case of $Sr(Cu_{1}3}Nb_{2}3})O_3$, some superlattice lines caused by threefold enlarging of fundamental unit cell were observed. And, the symmetry of B site octahedron and the bonding character of B-O bond have been studied by IR, ESR and diffuse reflection spectroscopy. It appeared that the symmetry and the bonding character are influenced by such factors as the size and the basicity of A cation.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.860-864
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• 1994

2nd-order rate constants have been measured spectrophotometrically for the reactions of 4-nitrophenyl benzoate (1), S-4-nitrophenyl thiobenzoate (2) and 4-nitrophenyl thionbenzoate (3) with alkoxides, aryloxides and thioaryloxides in absolute ethanol at 25.0 ${\pm}0.1$${\circ}C$. The substitution of O by polarizable S in the leaving group has little affected the reactivity of 2 toward the charge localized species (eg. $EtO^-$ and $CF_3CH_2O^-$), while the effect of the similar replacement in the carbonyl group has led to a decrease in reactivity by a factor of 10. However, the reactivity of these esters toward charge delocalized aryloxides has been found to be in the order $1<3{\le}2$. The effect of replaced sulfur atom on reactivity becomes more significant for the reaction with polarizable thioaryloxides, i.e. the reactivity increases in the order $1<2{\ll}3$. The difference in reactivity for the present system is attributed to a polarizability effect.

• Bulletin of the Korean Chemical Society
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• v.10 no.4
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• pp.335-339
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• 1989

Cholesteryl methyl ether$(CH_3OC_{27}H_{45})$ crystallizes in the monoclinic space group $P2_1$with a = 11.740 (8), b = 7.576 (5), c = 15.492 (10)${\AA},\; {\beta}\;= 110.39 (5)^{\circ}$, Z = 2, Dc = 1.03 g/$cm^3$ and Do = 0.96 g/$cm^3$. The intensities were collected on a Nonius CAD-4 diffractometer with Nb-filtered Mo-$K_{\alpha}$ radiation. The structure was solved by direct methods and refined by full matrix least-squares methods. The final R factor was 0.085 for 1479 observed reflections. Compared with other cholesterol derivatives, the cholesteryl ring and tail region of the molecule are normal. The molecular long axes are parallel to the [101] axis and molecules are packed together in a similar way to those in cholesteryl cliloride and bromide.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1507-1512
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• 2014

Recognition of Korean pre-service elementary school teachers concerning the factor for the environmental class was investigated and analyzed by the factorial analysis. Korean pre-service elementary school teachers are aware of the factor of 'participation in environment' as well as the factor of 'environmental knowledge' for the environmental class. Furthermore, they had a very positive attitude about the factor of 'participation in environment'.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.249-255
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• 2009

In order to calculate the processing and reduction factor between fresh and dry Welsh onion which was widely used as a dried agricultural ingredient of food in Korea. 7 pesticides such as pyridalyl, kresoxim-methyl, spinosad, flufenoxuron, difenoconazole, metconazole, and tebufenozide were tested. After 2 sites field trial conducted and measured water contents by drying at $60^{\circ}C$ and analyzed the pesticide residue. Water contents of fresh and dried Welsh onion are 89.2 and 10.2% respectively. Averages of processing factor showed 7.24 of pyridalyl, 2.85 of kresoxim-methyl, 7.43 of spinosad, 3.17 of flufenoxuron, 4.38 of difenoconazole, 2.40 of metconazole and 8.13 of tebufenozide into 2 field samples. Averages of Reduction factor showed 0.87 of pyridalyl, 0.35 of kresoxim-methyl, 0.88 of spinosad, 0.38 of flufenoxuron, 0.52 of difenoconazole, 0.29 of metconazole and 0.98 of tebufenozide. Residual amounts of pesticides in/on fresh Welsh onion reduced during drying process.

• Journal of Life Science
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• v.26 no.12
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• pp.1360-1366
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• 2016

Heat shock proteins (HSPs) are induced in response to various physiological or environmental stressors. However, the transcriptional activation of HSPs is regulated by a family of heat shock factors (HSFs). Fish models provide an ideal system for examining the biochemical and molecular mechanisms of adaptation to various temperatures and water environments. In this study, we examined the pattern differentials of heat shock factor 1 (HSF1) and expression of heat shock protein 70 (HSP70) in response to thermal stress in goldfish and mouse hepatocyte cultures by immune-blot analysis. Goldfish HSF1 (gfHSF1) changed from a monomer to a trimer at $33^{\circ}C$ and showed slightly at $37^{\circ}C$, whereas mouse HSF1 (mHSF1) did so at $42^{\circ}C$. This experiment showed similar results to a previous study, indicating that gfHSF1 and mHSF1 play different temperature in the stress response. We also examined the activation conditions of the purified recombinant proteins in human HSF1 (hmHSF1) and gfHSF1 using CD spectroscopy and immune-blot analysis. The purified recombinant HSF1s were treated from $25^{\circ}C$ to $42^{\circ}C$. Structural changes were observed in hmHSF1 and gfHSF1 according to the heat-treatment conditions. These results revealed that both mammal HSF1 (human and mouse HSF1) and fish HSF1 exhibited temperature-dependent changes; however, their optimal activation temperatures differed.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.553-556
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• 1993

Soybean nuclear extracts were prepared to examine the expression of SEF3 (soybean embryo factors 3), which binds to the upstream region of soybean ${\beta}-conglycinin$ ${\alpha}'$ subunit gene and is presumed to be a trans-acting factor for the expression of the gene. The relative levels of SEF3 binding activity in nuclear extracts of maturing soybean embryos were determined using the SE3 DNA probe containing two AACCCA hexanucleotides for gel mobility shift assay. The SEF3 activity increased in developing embryos from 16 to 32 days after pollination, whereas the mobility of the SE3-SE3-SEF3 complex decreased. The mobility of the complex was increased by the treatment of nuclear extracts with alkaline phosphatese, which could be inhibited by phosphate. Formation of the SE3-SEF3 complex was not affected by the binding buffer pH between 6.8 and 8.5.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.63-66
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• 1995

Soybean nuclear extracts were prepared to detect SEF3(soybean embryo factor 3), which is presumed to be a trans-acting factor for the expression of the soybean ${\beta}-conglycinin\;{\alpha}'$ subunit gene. To increase the specific activity of DNA probe during labeling with $[{\alpha}-^{32}P]$dATP, dATP was added to a final concentration of 1.1 mM during the chase reaction. It results in approximately four-fold increase of specific activity of the DNA probe. Effects of several modifications in preparation of soybean nuclear extracts were examined. It was found that glycerol is effective to stabilize SEF3 during the preparation of nuclear extracts and polyethylenimine could be used to increase the specific activity of SEF3 in nuclear extracts.