• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.70-80
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• 2011

Two new palladium (II) complexes, [Pd (phen)(pip-dtc)]$NO_3$ and [Pd(phen)(mor-dtc)]$NO_3$, (where phen is 1,10-Phenantroline, pip-dtc is piperidinedithiocarbamate anion and mor-dtc is morpholinedithiocarbamate anion) have been synthesized and characterized by elemental analysis, spectroscopic studies (FT-IR, $^1H$ NMR, UV-Vis) and conductance measurement. In these complexes, the dithiocarbamate ligands coordinate with Pd (II) center as bidentate with two sulfur atoms. These two complexes have been tested against chronic myelogenous leukemia cell line, K562. They show $IC_{50}$ values less than cisplatin and thus the mode of binding of the complexes to calf thymus DNA (CT-DNA) were investigated by ultraviolet difference and fluorescence spectroscopy. They can denature DNA, exhibit cooperative binding and intercalate into DNA. Several binding and thermodynamic parameters are also described.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.38-45
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• 2011

The complexation behavior of the $\alpha$-ketostabilized phosphorus ylides $Ph_3P$=CHC(O) $C_6H_4-X$ (X=Br, Ph) towards the transition metal ions mercury (II) and Silver (I) was investigated. The mercury(II) complex {$HgX_2$ [Y]} 2 ($Y_1$=4-bromo benzoyl methylene triphenyl phosphorane; X=Cl(1), Br(2), I(3), $Y_2$=4-phenyl benzoyl methylene triphenyl phosphorane; X=Cl(4), Br(5), I(6)) have been prepared from the reaction of $Y_1$ and $Y_2$ with $HgX_2$ (X=Cl, Br, I) respectively. Silver complexes [$Ag(Y_2)_2]$ X(X=$BF_4$(7), OTf(8)) of the $\alpha$-keto-stabilized phosphorus ylides ($Y_2$) were obtained by reacting this ylide with AgX (X=$BF_4$, OTf) in $Me_2CO$. The crystal structure of complexes (1) and (4) was discussed. These reactions led to binuclear complexes C-coordination of ylide and trans-like structure of complexes $[Y_1HgCl_2]_2$. $CHCl_3$ (1) and $[Y_2HgCl_2]_2$ (4) is demonstrated by single crystal X-ray analyses. Not only all of complexes have been studied by IR, $^1H$ and $^{31}P$ NMR spectroscopy, but also complexes 1-3 have been characterized by $^{13}$CNMR.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.151-156
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• 2010

Investigation of secondary bioactive metabolites from the fruiting bodies of Lactarius hatsudake led to the isolation of four azulene derivatives by means of repeated column chromatography and preparative HPLC, and they were identified as 1-formyl-4-methyl-7-isopropyl azulene (1), lactaroviolin (2), 4-methyl-7-isopropyl-azulene-1-carboxylic acid (3), and 1-formyl-4-methyl-7-(1-hydroxy-1-methylethyl) azulene (4) by their physico-chemical properties and spectroscopic analysis. The isolated compounds were evaluated for the effects on modulation of cytokines in natural killer cell line (NK92 cells). Compounds 1 and 4 strongly inhibited IFN-$\gamma$ production in a dose-dependent manner, corresponding to 101.3 % and 92.7 % inhibition at 400 ${\mu}M$, and 11.9 % and 24.1 % at 100 ${\mu}M$, respectively, whereas compounds 2 and 3 showed weak inhibitory effect on INF-$\gamma$ production, corresponding to 45.9 % and 18.0 % inhibition at 400 ${\mu}M$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.129-136
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• 2010

In order to evaluate anti-wrinkle activity of Carex humilis extract, free radical scavenging activity, elastase inhibitory activity and reduction of expression Matrix metalloproteinase-1 (MMP-1) mRNA and MMP-1 protein were investigated. The roots of Carex humilis were extracted with 95 % ethanol and successively partitioned with organic solvents with increasing polarity of the solvents. Each fraction of organic solvent were investigated by using free radical scavenging activity and elastase inhibitory activity test. Among them, EtOAc fraction showed antioxidant activity ($SC_{50}$=4.89 ${\mu}g/mL$) and elastase inhibitory activity ($IC_{50}$=23.5 ${\mu}g/mL$). EtOAc fraction was developed on silica gel by open-column chromatography and consecutively re-developed on C18 resin by prep-HPLC to give ${\alpha}$-viniferin as a major component, which was confirmed by spectrometric analysis. In the assay on expression of MMP-1 mRNA by RT-PCR and protein by western-blot, EtOAc layer (10 ~ 100 ${\mu}g/mL$) was reduced about 50 ~ 60 %, 50 ~ 65 % respectively and ${\alpha}$-viniferin (0.5 ~ 2 ${\mu}g/mL$) was inhibited about 60 ~ 75 %, 55 ~ 65 % respectively in human fibroblast. Therefore, our findings suggest that EtOAc layer of Carex humilis containing ${\alpha}$-viniferin can be useful as an active ingredient for cosmeceuticals of anti-wrinkle effects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.80-85
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• 2019

Vanadium dioxide is a well-known metal-insulator phase transition material. Lots of researches of vanadium redox flow batteries have been researched as large scale energy storage system. In this study, vanadium oxide($VO_x$) thin films were applied to cathode for lithium ion battery. The $VO_x$ thin films were deposited on Si substrate($SiO_2$ layer of 300 nm thickness was formed on Si wafer via thermal oxidation process), quartz substrate by RF magnetron sputter system for 60 minutes at $500^{\circ}C$ with different RF powers. The surface morphology of as-deposited $VO_x$ thin films was characterized by field-emission scanning electron microscopy. The crystallographic property was confirmed by Raman spectroscopy. The optical properties were characterized by UV-visible spectrophotometer. The coin cell lithium-ion battery of CR2032 was fabricated with cathode material of $VO_x$ thin films on Cu foil. Electrochemical property of the coin cell was investigated by electrochemical analyzer. As the results, as increased of RF power, grain size of as-deposited $VO_x$ thin films was increased. As-deposited thin films exhibit $VO_2$ phase with RF power of 200 W above. The transmittance of as-deposited $VO_x$ films exhibits different values for different crystalline phase. The cyclic performance of $VO_x$ films exhibits higher values for large surface area and mixed crystalline phase.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.309-314
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• 2022

Carbon dots (CDs) are few nanometer-sized carbon-based nanoparticles and emerging candidate materials in various fields such as biosensors and bioimaging due to their excellent optical properties and high biocompatibility. However, most CDs, emitting blue light, have limited their application in biomedical fields due to the low penetration of short-wavelength lights into the biological system. Therefore, there has been enormous need to develop long-wavelength emitting CDs. In this study, red-emitting CDs were successfully synthesized through the hydrothermal reaction of p-phenylenediamine with hydrochloric acid. In addition, the effect of the amount of hydrochloric acid on the formation of carbon dots, resulting in the variation of the chemical structures of CDs, were investigated, which was confirmed with the intensive structural analyses using infrared and X-ray photoelectron spectroscopy. It was found that the chemical structure of CDs governed their optical properties and quantum yield. Therefore, this study provides an insight into the role of acid in forming red-emitting CDs as the optimal probe for biomedical application.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.188-194
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• 2022

This work presents a non-destructive and straightforward approach to assemble a large-scale conductive electronic film made of a pre-treated single-walled carbon nanotube (SWCNT) solution. For effective electron transfer between the immobilized enzyme and SWCNT electronic film, we optimized the pre-treatment step of SWCNT with p-terphenyl-4,4"-dithiol and dithiothreitol. Glucose oxidase (GOx, a model enzyme in this study) was immobilized on the SWCNT electronic film following the positively charged polyelectrolyte layer deposition. The glucose detection was realized through effective electron transfer between the immobilized GOx and SWCNT electronic film at the negative potential value (-0.45 V vs. Ag/AgCl). The SWCNT electronic film-based glucose biosensor exhibited a sensitivity of 98 ㎂/mM·cm². In addition, the SWCNT electronic film biosensor showed the excellent selectivity (less than 4 % change) against a variety of redox-active interfering substances, such as ascorbic acid, uric acid, dopamine, and acetaminophen, by avoiding co-oxidation of the interfering substances at the negative potential value.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.529-538
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• 2016

This study, multispectral and hyperspectral sensors were utilized to use radiometric cross validation for the purpose of radiometric quality evaluation of a 'KOMPSAT-3'. Images of EO-1 Hyperion and Landsat-8 OLI sensors taken in PICS site were used. 2 sections that have 2 different types of ground coverage respectively were selected as the site of cross validation based on aerial hyperspectral sensor and TOA Reflectance. As a result of comparison between the TOA reflectance figures of KOMPSAT-3, EO-1 Hyperion and CASI-1500, the difference was roughly 4%. It is considered that it satisfies the radiological quality standard when the difference of figure of reflectance in a comparison to the other satellites is found within 5%. The difference in Blue, Green, Red band was approximately 3% as a comparison result of TOA reflectance. However the figure was relatively low in NIR band in a comparison to Landsat-8. It is thought that the relatively low reflectance is because there is a difference of band passes in NIR band of 2 sensors and in a case of KOMPSAT-3 sensor, a section of 940nm, which shows the strong absorption through water vapor, is included in band pass resulting in comparatively low reflectance. To overcome these conditions, more detailed analysis with the application of rescale method as Spectral Bandwidth Adjustment Factor (SBAF) is required.

• Journal of Conservation Science
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• v.30 no.3
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• pp.249-261
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• 2014

This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.

• Journal of the Korean Magnetics Society
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• v.12 no.1
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• pp.14-19
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• 2002

The iron-doped perovskite La$_{0.67}$Sr$_{0.33}$Mn$_{0.99}$$^{57}$Fe$_{0.01}$O$_3$compound has been studied by x-ray diffraction, Mossbauer spectroscopy, and vibrating sample magnetometry. The single phase of the polycrystalline La$_{0.67}$Sr$_{0.33}$Mn$_{0.99}$$^{57}$Fe$_{0.01}$O$_3$powder has been prepared by a waterbased solgel method. Crystalline La$_{0.67}$Sr$_{0.33}$Mn$_{0.99}$$^{57}$Fe$_{0.01}$O$_3$was a rombohedral structure with lattice parameters a$_{0}$=5.480 $AA$, $alpha$=60.259$^{circ}$. Mossbauer spectra of La$_{0.67}$Sr$_{0.3}$/Mn$_{0.99}$$^{57}$Fe$_{0.01}$O$_3$have been taken at various temperatures ranging from 20 to 400 K. As the temperature increases toward the Curie temperature, T$_{c}$=375 K, the Mossbauer spectra show line broadening and the difference between the 1,6 and 3,4 linewidths is caused by the anisotropic hyperfine field fluctuation. The anisotropic field fluctuation of +H (P$_{+}$=0.80) is greater than -H (P$_{-}$=0.20). We calculated that the anisotropy energy was 124.01 erg/cm$^3$for T=150 K which is associated with the large line broadening.