• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.33-37
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• 2004

Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$ has been studied with Mossbauer spectroscopy, x-ray diffraction, vibrating sample magnetometer (VSM), and magnetoresistance (MR) measurement. The crystal structure was determined to be a cubic spinel with lattice parameter a$_{0}$=9.9880 $\AA$. The MR measurements show a semiconductor behavior below 110 K and metal behaved above 100 K. The temperature dependence of magnetization of Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$ was reported. In addition to a large irreversibility between the zero-field-cooling (ZFC) and the field-cooling (FC) magnetization at applied field H=100 Oe, a cusp-like anomaly was observed in both the FC and ZFC curves. It shifted toward the lower temperature region with increasing magnetic field, and then showed convex type maximum at 110 K, under the applied field of 5 kOe. The Mossbauer spectra were measured from 15 K to room temperature. The asymmetric line broadening was observed for the sample Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$, and it was considered to be dynamic Jahn-Teller relaxation. The charge state of Fe ions was ferrous in character. The unusual reduction of magnetic hyperfine field below 110 K was interpreted in terms of cancellation effect between the mutually opposite orbital current field (H$_{L}$) and Fermi contact field (H$_{C}$).

• Journal of Mushroom
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• v.12 no.2
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• pp.107-116
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• 2014

Gloeostereum incarnatum is an edible and medicinal mushroom belongs to Family Cyphellaceae of Polyporales, Basidiomycota. The purpose of this study was to investigate the free radical scavenging, anti-inflammatory, and melanin synthesis inhibitory activities of fruiting bodies of Gloeostereum incarnatum. In the free radical scavenging activities, the mushroom extracts showed good 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and chelating activity on the ferrous ions compared with the positive control, BHT. The mushroom extract suppressed nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells in dose dependant manners. Significant reduction of paw edema of rats were observed at 2~6 h after administration with 50 mg/kg of the methanol and hot-water extracts, which were comparable with treatment of 5 mg/kg of indomethacin, the positive control. The melanin synthesis of Melanoma B16/F10 cells treated with $100{\mu}g/mL$ of the methanol and hot water extracts decreased melanin concentration to 50% and 45% compared with the control, arbutin. Therefore, the experimental results showed that methanol and hot-water extracts of Gloeostereum incarnatum fruiting bodies might be used for good sources of anti-inflammatory, free radical scavenging, and skin whitening agents for human health.

• Membrane and Water Treatment
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• v.6 no.5
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• pp.365-378
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• 2015

Herein, the preparation of anion exchange membrane (AEM) from brominated poly(2,6-dimethyl 1,6-phenylene oxide) BPPO and dimethylaniline (DMA) by phase-inversion process is reported. Anion exchange membranes (AEMs) are prepared by varying the DMA contents. Prepared AEMs show high thermal stability, water uptake (WR) around 202% to 226%, dimensional change ratios of 1.5% to 2.6% and ion exchange capacities (IECs) of 0.34 mmol/g to 0.82 mmol/g with contact angle of $59.18^{\circ}$ to $65.15^{\circ}$. These membranes are porous in nature as confirmed by SEM observation. The porous property of membranes are important as it could reduce the resistance of transportation of ions across the membranes. They have been used in diffusion dialysis (DD) process for recovery of hydrochloric acid (HCl) from the mixture of HCl and ferrous chloride ($FeCl_2$). Presence of $-N+(CH_3)_2C_6H_5Br^-$ as a functional group in membrane matrix facilitates its applications in DD process. The dialysis coefficients of hydrochloric acid ($U_H$) of the membranes are in range of 0.0016 m/h to 0.14 m/h and the separation factors (S) are in range of 2.09 to 7.32 in the $HCl/FeCl_2$ system at room temperature. The porous membrane structure and presence of amine functional group are responsible for the mechanism of diffusion dialysis (DD).

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.76-82
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• 2006

Fenton's reaction are difficult to apply in the field due to the low pH requirements for the reaction and the loss of reactivity caused by the precipitation of iron (II) at neutral pH. Moreover, Fenton-like reactions using iron mineral instead of injection of iron ion as a catalyst are operated to get high removal result at low pH. Because hydroxyl radical can generate at the surface of iron mineral, there are competition with a lot of hydroxide at around neutral pH. On the other side, to operate Fenton's reaction series at neutral pH, modified Fenton reaction is suggested. The complexes, composed by iron ions (ferrous ion or ferric ion)-chelating agent, could be acted as a catalyst and presented in the solution at neutral pH. However, modified Fenton reaction requires a lot of hydrogen peroxide. Accordingly, the purpose of this experiment was to effectively combine Fenton-like reaction and modified Fenton reaction for extending application of Fenton's reaction. i.e., injecting chelating agents in Fenton-like reaction at around neutral pH is increasing the concentration of dissolved iron ion and highly promoting the oxidation effect. 2,4,6-trinitrotoluene (TNT) was used as a probe compound for comparing reaction efficiencies in this study. If the concentration of dissolved iron ion in combined Fenton process were existed more than 0.1 mM, the total TNT removal were increased. Magnetite-NTA system showed the best TNT removal (76%) and Magnetite-EDTA system indicated about 56% of TNT removal. The results of these experiments proved more promoted 40-60% of TNT removal than Fenton-like reaction's.

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.34-37
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• 2007

The crystallographic and magnetic properties of $Fe_{0.9}Zn_{0.1}Cr_2S_4$ have been studied by X-ray diffractometer(XRD), vibrating sample magnetometer(VSM) and $M\"{o}ssbauer$ spectroscopy measurement. The crystal structure was determined by the normal cubic spinel of space group Fd3m and the lattice constant was $a_0=9.9967\;{\AA}$. The specific phenomenon which looks like cusp pattern at 77 K was observed in magnetization corves(ZFC : Zero Field Cooling) under 100 Oe applied field. $N\acute{e}el$ temperature($T_N$) was determined to be 153 K by VSM and $M\"{o}ssbauer$ spectra. The asymmetric 8-line profile has been observed at 4.2 K, which was attributed by the colossal electric quadupole interaction(${\Delta}E_Q$), ${\Delta}E_Q$ has 2.22 mm/s at 4.2 K. The ${\Delta}E_Q$ abruptly decreases around 77 K and then it disappears above 77 K with diminishing of 8-line pattern. The isomer shift $\delta$ at room temperature is 0.48 mm/s relative to Fe metal, which means that the charge state of Fe ions is ferrous in character.

• Journal of Life Science
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• v.26 no.9
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• pp.1074-1081
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• 2016

Mistletoes are hemi-parasitic plant growing on different host tree and shrubs. They are traditionally used in folkloric medicine for the treatment of diarrhea, cough, diabetes, hypertension, cancer and skin infection. The purpose of this study was to determine the contents of phenolics and antioxidant activity of 70% ethanol, 100% methanol and hot water extracts of Jeju camellia mistletoe (Korthalsella japonica Engl.). Ethanol was most effective in extracting total phenols (7,427 mg gallic acid equivalent (GAE)/100 g) and flavonoid (1,777 mg rutin equivalent (RE)/100 g). The free radical scavenging activity, 1,1-diphenyl-2-picryl hydrazyl (DPPH) (EC₅₀ = 7.8 mg/ml) and hydrogen peroxide (H₂O₂) (EC₅₀ = 1.4 mg/ml), and the capacity for chelating metal ions (EC₅₀ = 8.0 mg/ml) and reducing power (EC₅₀ = 14.9 mg/ml) of the samples also higher in ethanolic extracts. The strong correlation (r² = −0.996～−0.881) between antioxidant capacities and the phenolic contents implied that phenolic compounds are a major contributor to the antioxidant activity of the ethanolic extracts of Jeju camellia mistletoe. As conclusions, Jeju camellia mistletoe contains bioactive substances with a potential for reducing the physiological as well as oxidative stress and this could explain the suggested cancer preventive effect of these plants as well as their protective role on other major diseases.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.104-111
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• 2013

Phellinus baumii is a medicinal mushroom used in Asian countries for a long period of time. The purpose of this study was to investigate the skin whitening activities of methanol extracts from fruiting bodies of P. baumii. To evaluate the antioxidant activities of the extract, polyphenol and flavonoid contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and chelating activity on ferrous ions were studied. For assay of skin whitening activities, tyrosinase and DOPA inhibitory activities, and tyrosinase and melanin synthesis inhibitory activities of B16/F10 melanoma cells treated with the methanol extract were investigated. The total polyphenol content of P. baumii methanol extract was 4.19. DPPH scavenging ability of P. baumii methanol extract was 88.26% in $25{\mu}g/mL$ concentration. We tested tyrosinase inhibitory activity and melanin contents in melanoma cells. The tyrosinase activity was inhibited to 65.17% at the concentration of $125{\mu}g/mL$ and melanin synthesis was inhibited to 57.61% at the concentration of $25{\mu}g/mL$. Overall, the experimental results showed that P. baumii methanol extract had inhibitory activities of tyrosinase and melanin synthesis by dose dependent manner in B16/F10 melanoma cells. Strong ultra-violet absorption spectra in the range of 270~370 nm indicated that ethanol extract of P. baumii could protect the skin from UV. Therefore, P. baumii methanol extract might be used for development of skin whitening, anti-UV and skin care agents.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.323-330
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• 2008

The study presents the results of 1,4-dioxane degradation using zero valent (Fe$^0$) or Fe$^{2+}$ ions with and without UV. During the reaction, the change of [Fe$^{2+}$] and [Fe$^{2+}$]/[Fe(t)], the concentration ratio of ferrous ion to total iron ion in solution was measured. Less than 10% degradation of 1,4-dioxane was observed by UV-only, Fe$^0$-only, and Fe$^{2+}$-only conditions, and also the changes of [Fe$^{2+}$] and [Fe$^{2+}$]/[Fe(t)] were minimal in each reaction. However, the oxidation of Fe$^0$ was enhanced with the irradiation of UV by approximately 25% and the improvement of 1,4-dioxane degradation was observed. Fenton reaction ($Fe^{2+}+H_2O_2$) showed higher degradation efficiency of 1,4-dioxane until 90 min, which of the degradation was stopped after that time. In the reaction of Fe$^{2+}$ and UV, the ratio of [Fe$^{2+}$]/[Fe(t)] decreased then slowly increased after a certain time indicating the reduction of Fe3+ to Fe$^{2+}$. In case of Fe$^0$ in the presence of UV, the first-order rate constant was found to be 1.84$\times$10$^{-3}$ min$^{-1}$ until 90 min, and then changed to 9.33$\times$10$^{-3}$ min$^{-1}$ when the oxidation of Fe$^{2+}$ mainly occurred. In this case [Fe$^{2+}$]/[Fe(t)] kept decreasing for the reaction. However, the addition of perchlortae (ClO$_4^-$) in the reaction of Fe$^0$ and UV induced the continuous increase of [Fe$^{2+}$]/[Fe(t)] ratio. The results mean the primary degradation factor of 1,4-dioxane is the oxidation by the radicals generated from the redox reaction between Fe$^{2+}$ and Fe$^{3+}$. Also, both UV and ClO$_4^-$ played the role inducing the reduction of Fe$^{3+}$, which is important to degrade 1,4-dioxane by enhancing the generation of radicals.

• Journal of Mushroom
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• v.11 no.2
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• pp.99-106
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• 2013

This study was initiated to investigate the skin whitening activities of methanol extracts from fruiting bodies of I. obliquus. The total polyphenols and flavonoids contents of I. obliquus methanol extracts were 31.85 mg/g and 28.33 mg/g, respectively. The methanol extract of the mushroom treated on B16/F10 melanoma and NIH3T3 cell lines did not show cytotoxic activity. 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and chelating activity on ferrous ions of I. obliquus methanol extract were lower than those of positive control, tocopherol and BHT. The tyrosinase and L-DOPA inhibitory activities of the extract were lower than those of positive control, kojic acid and ascorbic acid. The tyrosinase and melanin synthesis inhibitory activities of the melanoma cells treated with the extract were comparable with positive control, arbutin. The experimental results suggested that methanol extract of I. obliquus contained inhibitory activities of tyrosinase and melanin synthesis in the B16/F10 melanoma cells by dose dependent manner. High ultra-violet absorption spectra in the range of 280-350 nm showed that I. obliquus extract could protect skin from UV radiation damage. Therefore, fruiting bodies of I. obliquus can be used for developing skin whitening, anti-UV and skin care agents.