• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.93-98
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• 1983

Apple sugaring and apple nectar gel were treated with coating agent, and then the rate of weight loss, browning reaction and fungi growth on the storage conditions of those were investigated. The results obtained were summarized as follows; The composition of sucrose, D-sorbitol, corn syrup, gelatin, arabia gum, citric acid, sodium citrate and sodium ascorbate as a nontoxic coating agent was desirable to repress weight loss browning reaction and fungi growth of apple sugaring and apple nectar gel. It was the most effective method that apple sugaring was treated with the coating agent and refrigerated with double packaging. The contraction by weight loss, browning reaction and fungi growth of apple nectar gel treated with the coating agent and freezed with double packaging were repressed.

• BMB Reports
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• v.47 no.7
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• pp.382-387
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• 2014

Corn silk (CS) has long been consumed as a traditional herb in Korea. Maysin is a major flavonoid of CS. The effects of maysin on macrophage activation were evaluated, using the murine macrophage RAW 264.7 cells. Maysin was isolated from CS by methanol extraction, and preparative $C_{18}$ reverse phase column chromatography. Maysin was nontoxic up to $100{\mu}g/ml$, and dose-dependently increased TNF-${\alpha}$ secretion and iNOS production by 11.2- and 4.2-fold, respectively, compared to untreated control. The activation and subsequent nuclear translocation of NF-${\kappa}B$ was substantially enhanced upon treatment with maysin ($1-100{\mu}g/ml$). Maysin also stimulated the phosphorylation of Akt and MAPKs (ERK, JNK). These results indicated that maysin activates macrophages to secrete TNF-${\alpha}$ and induce iNOS expression, via the activation of the Akt, NF-${\kappa}B$ and MAPKs signaling pathways. These results suggest for the first time that maysin can be a new immunomodulator, enhancing the early innate immunity.

• Advances in nano research
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• v.4 no.4
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• pp.295-307
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• 2016

The present research work reports a low temperature ($40^{\circ}C$) chemical precipitation technique for synthesizing hydroxyapatite (HAp) nanoparticles of spherical morphology through a simple reaction of calcium nitrate tetrahydrate and di-ammonium hydrogen phosphate at pH 11. The crystallinity of the single-phase nanoparticles could be improved by calcinating at $600^{\circ}C$ in air. Thermogravimetric and differential thermal analysis (TG-DTA) revealed the synthesized HAp is stable up to $1200^{\circ}C$. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) studies confirmed the formation of spherical nanoparticles with average size of $23.15{\pm}2.56nm$ and Ca/P ratio of 1.70. Brunauer-Emmett-Teller (BET) isotherm of the nanoparticles revealed their porous structure with average pore size of about 24.47 nm and average surface area of $78.4m2g^{-1}$. Fourier transform infrared spectroscopy (FTIR) was used to confirm the formation of P-O, OH, C-O chemical bonds. Cytotoxicity and MTT assay on MG63 osteogenic cell lines revealed nontoxic bioactive nature of the synthesized HAp nanoparticles.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.500-506
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• 2008

Apigenin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. In this study we found that apigenin stimulated melanin synthesis in a dose-dependent manner in B16 murine melanoma cells. Since in our previous study $K^+$-$Cl^-$-cotransport (KCC) has been shown to mediate the mechanism of action of apigenin in neuronal cells, we further investigated the role of KCC in the melanogenesis-stimulating effect of apigenin in B16 cells. At nontoxic concentrations apigenin induced $Cl^-$-dependent $K^+$ efflux, a hallmark of KCC activity, which was markedly prevented by a specific KCC inhibitor R-(+)-[(2-n-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-1H-inden-5-yl)oxy]acetic acid (DIOA). These results indicate that KCC is functionally present, and activated by apigenin in the B16 cells. In addition, the apigenin-induced stimulation of melanogenesis was also significantly inhibited by DIOA. NEthylmaleimide (NEM), a known KCC activator, induced $Cl^-$ efflux and stimulated melanogenesis in a concentration-dependent fashion. Both effects of NEM were significantly inhibited by DIOA. Taken together, these results suggest that apigenin can modulate melanogenesis through the activation of a membrane ion transporter, KCC in B16 cells. These results further suggest that apigenin may be a good candidate in the therapeutic strategy for hypopigmentation disorders, such as vitiligo.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.238-245
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• 2011

In this study, we investigated antioxidative activity, antibacterial activity against pathogenic strains including methicillin resistant Staphylococcus aureus (MRSA), and tyrosinase inhibitory activity in 75% ethanol extract of Taraxacum coreanum and its fractions. The total polyphenol and flavonoid contents of the extract were 238.59mg/g and 33.18mg/g and the total polyphenol and flavonoid contents of the ethyl acetate fraction were 427.81mg/g and 148.90mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate and butanol fraction were 38.40${\mu}g/ml$ and 82.28 ${\mu}g/ml$, respectively. In antibacterial activity by the disc diffusion assay against S. aureus, S. epidermidis and MRSA, the ethyl acetate fraction showed stronger antibacterial activity than other fractions and the extract. Especially, the ethyl acetate fraction was exhibited effective antibacterial activity against MRSA. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited Raw 264.7 cell viabilities of 96.32~143.21% as nontoxic result in concentration of 5~100 ${\mu}g/ml$. As a result, the ethyl acetate fraction of the 75% ethanol extract from T. coreanum could be applicable to functional materials for related fields.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1184-1192
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• 2011

A bacterial isolate (strain JS-2) characterized as Bacillus sp. was challenged with high concentrations of toxic selenite ions. The microbe was found to transform the toxic, soluble, colorless selenite (${SeO_3}^{2-}$) oxyions to nontoxic, insoluble, red elemental selenium ($Se^0$). This process of biotransformation was accompanied by cytoplasmic and surface accumulation of electron dense selenium ($Se^0$) granules, as revealed in electron micrographs. The cells grown in the presence of selenite oxyions secreted large quantities of extracellular polymeric substances (EPS). There were quantitative and qualitative differences in the cell wall fatty acids of the culture grown in the presence of selenite ions. The relative percentage of total saturated fatty acid and cyclic fatty acid increased significantly, whereas the amount of total unsaturated fatty acids decreased when the cells were exposed to selenite stress. All these physiological adaptive responses evidently indicate a potentially important role of cell wall fatty acids and extracellular polymeric substances in determining bacterial adaptation towards selenite-induced toxicity, which thereby explains the remarkable competitiveness and ability of this microbe to survive the environmental stress.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.357-362
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• 2007

AZO(Aluminum-doped Zinc Oxide) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with ITO(Indium Tin Oxide). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$ for 2 hr with $N_2$ atmosphere. The AZO films were used as an anode contact to fabricate OLEDs(Organic Light Emitting Diodes). OLEDs with $AZO/TPD/Alq_3/Al$ configuration were fabricated by thermal evaporation. We investigated that the electric, structural and optical properties of AZO thin films, which measured using the methods of XRD, SEM, Hall measurement and Spectrophotometer. The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.318.1-318.1
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• 2013

Nowadays Cu2ZnSnS4 (CZTS) solar cell is attracting a lot of attention as a strong alternative to CIGS solar cell due to nontoxic and inexpensive constituent elements of CZTS. From various processes for the fabrication of CZTS solar cell, solution-based deposition of CZTS thin films is well-known non-vacuum process and many researchers are focusing on this method because of large-area deposition, high-throughput, and efficient material usage. Typically the solution-based process consists of two steps, coating of precursor solution and annealing of the precursor thin films. Unlike vacuum-based deposition, precursor solution contains unnecessary elements except Cu, Zn, Sn, and S in order to form high quality precursor thin films, and thus the precise control of precursor thin film preparation is essential for achieving high efficient CZTS solar cells. In this work, we have investigated the effect of preparation condition of CZTS precursor thin films on the performance of CZTS solar cells. The composition of CZTS precursor solution was controlled for obtaining optimized chemical composition of CZTS absorber layers for high-efficiency solar cells. Pre-annealing process of the CZTS precursor thin films was also investigated to confirm the effect of thermal treatment on chemical composition and carbon residues of CZTS absorber layers. The change of the morphology of CZTS precursor thin film by the preparation condition was also observed.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.124-132
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• 2015

Echinacea purpurea (L.) Moench (purple cone flower) is an important medicinal plant; it can enhance immunity, relieve pain, and reduce inflammation, and also has hormonal, antiviral, and antioxidant effects. Adventitious root biomass of Echinacea purpurea was produced in commercial-scale bioreactors for use as a dietary supplement in the food industry and in traditional medicine. Biosafety and toxicological evaluations of tissue-cultured Echinacea purpurea adventitious roots (TCEPARs) were performed. Reverse mutation and chromosomal aberration tests showed no significant mutagenicity. Furthermore, repeated four-week oral dose tests performed in Sprague-Dawley rats did not show any notable changes in the general behavior of the rats, in the gross appearance of their internal organs, or in their mortality rate. There were no differences between the control group and the treatment group in parameters such as absolute body weight, hematology, blood chemistry, and absolute and relative organ weights. These findings indicate that TCEPARs are safe and nontoxic when consumed at an average dietary level and can be used as raw material for traditional medicine and the food industry.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.336-338
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• 2008

본 연구에서는 EU에서 발효되는 6대 규제유해물질(Pb, Hg, Cd, $C^{6+}$, PBB/PBDE)과 환경부 규제유해물질에 의해 도료의 유해조성물질을 제한하게 됨에 따라 VOC(휘발성유기화합물) 배출이 적고, 브롬계/할로겐계를 탈피하여 인체안전성 확보 및 환경오염을 최소화하며, 방염제 형식승인 및 검정기술기준 (KOFEIS 0201)에 부합하는 수용성 유 무기계 난연도료를 개발하였다. 친환경적인 난연도료 제조에 대한 최적조건으로 Mg(OH)$_2$, $Sb_2O_3$, 붕산아연을 1:2:2로 혼합한 난연제 그리고 바인더(마이셸 2%)와 물의 비율을 1:1로 제조한 후, 난연제:(바인더+물)을 1:1로 제조한 난연도료 3의 성능이 가장 우수하였다.