• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.9-14
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• 1991

In order to investigate electronic and magnetic properties of $Fe_{16}N_{2}$ ferromagnet, we have performed electronic structure calculations employing the self-consistent local density functional LMTO(linearized muffin tin orbital) band method. We have obtained the ground state parameters, such as band structures, density of states, Stoner parameters, and magnetic moments. Based on these results, we have investigated microscopically the magnetic structure and the enhancement of Fe magnetic moments in this compound. Magnetic moments of 3 types of Fe(Fe I, Fe II and Fe III) in $Fe_{16}N_{2}$ are 2.13, 2.50, and $2.85\;{\mu}_{B}$, respectively. Large enhancement of Fe magnetic moment is observed in Fe II and Fe III, which are located rather far from N. This implies that local environment is very important in determining the Fe magnetic moments in this compound. Our value of average magnetic moment per Fe atom. $2.50\;{\mu}_{B}$, is a bit smaller than the reported estimate, $-3.0\;{\mu}_{B}$, from the experiment.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.786-787
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• 2006

The magnetic inductance of nanocrystalline $Fe_{73}Si_{16}B_7Nb_3Cu_1$ and an amorphous FeSiB powder sheet has been investigated to identify RFID performance. The powder was mixed with binder and solvent and tape-casted to form films. Results show annealing significantly influenced on the inductance of the material. The surface oxidation of the particles was the main reason for the reduced inductance. The maximum inductance of $Fe_{73}Si_{16}B_7Nb_3Cu_1$ alloy was about $88{\mu}H$ at 17.4 MHz, about 65% greater compared to the FeSiB alloy. The higher inductance in the nanocrystalline alloy indicates it may be used as a potential replacement of current RFID materials.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.5 no.1
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• pp.103-118
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• 1999

The activity of N-acetylglucosamitnyltransferase(GnT) III and V on a Melanoma B-16 was examined after incubation with interleukin 1 (IL-1). While augumenting cell proliferation, IL-1 resulted in a decrease of GnT-III activity and an increase of GnT-V activities. Consistant with this, Melanoma B-16 cultured with IL-1 showed increased affinlity to Daturam stramonium lectin, which recognizes asialo-tri- and asialeo-tetra-antenery N-linked oligosaccharides. These results indicate that IL-1 modulate glycosyltransferase activity and the oligosaccharide structure of target cells. On the other hand, to investigate whether or not TKM-SG affect GnT-V gene expression in lung metastatic carcinoma, we used RT-PCR methods. TKM-SG treated cell lines showed low levels of secretion of GnT-V mRNA transcription as elucidated by RT-PCR. Thus, with together lower GnT-V activity levels in the medium, TKM-SG was highly effective for lung cancer metastasis treatment and it was concluded that the medicine can be used as a potent anti-lung cancer metastasis medicine.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.104-117
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• 2009

Objective : Melanin is one of the most important facor in skin color. Melanin protects human skin from ultraviolet radiation otherwise it causes melanin pigmentation. So this experiment is carried out for test whether Scutellaria baicalensis Georgi(SBG) inhibits melanin synthesis and tyrosinase activity in mouse B16 melanoma cells. Method : The melanin synthesis inhibition effects of SBG were examined by in vitro melanin production assay. We assessed inhibitory effects of SBG on melanin contents from B16F1 melanoma cell, on tyrosinase activity(cell and cell free system), effect of SBG on the expression tyrosinase, Microphthalmia-associated Transcription Factor(MITF), Extracellular signal-regulated Kinase(ERK). Result : SBG inhibited melanin synthesis induced $\alpha$-MSH($\alpha$-Melanin Stimulating Hormone) in B16F1. SBG inhibited tyrosinase activity and expression. And SBG down-regulates MITF and stimulated ERK activation in B16F1. Conclusion : According to above results, SBG was improved its suppression effect to the inhibition of melanin synthesis, tyrosinase activation, and tyrosinase promotor activation. So SBG is considered to be used for an strong source of skin whitening effect.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.95-95
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• 2018

In this study, we investigated the effect of branch extracts from Vaccinium oldhamii (VOB) on melanin synthesis in B16F10 cells. VOB promoted melanin production in absence or presence of ${\alpha}$-melanocyte-stimulating hormone (${\alpha}-MSH$) in B16F10 cells. However, VOB did not affect the expression of tyrosinase and TRP-1 associated with melanin synthesis at the mRNA and protein level in B16F10. But, VOB decreased TRP-2 protein level and induced tyrosinase activation in B16F10 cells. Inhibition of tyrosinase activity and tyrosinase knockdown attenuated VOB-mediated melanin synthesis. In conclusion, it is thought that VOB may stimulate melanin synthesis through activating tyrosinase activity.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.98-104
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• 2007

The carbon fiber reinforced carbon composite (CFRC) materials are necessary for the advanced industries that require the thermal resistance. And the development and research for CFRC has been in progress in the field of aerospace and defense industry. CFRC have several advantages and special properties such as excellent anti ablation, outstanding strength retention at very high temperature, high heat capacity and thermal transport, high specific stiffness and strength, and high thermal shock resistance. They have been used as aircraft brake, rocket nozzle, nose cones, jet engine turbine wheels, and high speed craft. Since the technology related to CFRC was prohibited from importing and exporting, we developed our own technology to produce F-16 B32 brake disk made out of CFRC, and then we performed various tests to observe the characteristics of CFRC-based brake disk developed in this study in view of density, strength, friction, specific heat, and heat conductivity.

• YAKHAK HOEJI
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• v.59 no.4
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• pp.177-183
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• 2015

The mechanism of melanogenesis induced by cyclosporin A (CsA) was investigated in B16 melanoma cells. CsA stimulated the production of melanin in a dose-dependent manner in the cells. In addition, CsA increased intracellular $Ca^{2+}$ concentration in a dose-related fashion. Treatment with BAPTA/AM, an intracellular $Ca^{2+}$ chelator significantly inhibited the CsA-induced intracellular melanin synthesis. CsA profoundly induced $Cl^-$ efflux, which was significantly blocked by niflumic acid (NFA) and flufenamic acid (FFA), specific and nonspecific inhibitors of $Ca^{2+}$-activated $Cl^-$ channels (CaCCs), respectively. Furthermore, these inhibitors of CaCCs significantly inhibited the CsA-induced stimulation of melanin synthesis. Taken together, these results suggest that the activation of CaCCs may play an important role in the CsA-induced stimulation of melanin synthesis in B16 cells. These results further suggest that CaCCs may be a good target for the management of hyperpigmentation of the skin reported in the patients treated with CsA.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.2
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• pp.226-237
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• 1998

In recent SATCOM systems, transparent transponders are widely used. The transponder is, however, the most vulnerable part in SATCOM systems against jamming interference. All signals within the transponder bandwidth are frequency-converted and retransmitted with IM(intermodulation) products. In this paper, the method is proposed that makes the SJR(Signal-to-Jammer ratio) better. The bandwidth spreading of the user signal can reduce the jammers effects. The geostationary satellite system is modeled to simulate and to certificate the capability of suppression of jammers by DSSS. If signal is partially-overlapped by jammer and PG(processing gain) is 16.9 [dB] for 2ASK jammer and about 16.8 [dB] for QPSK jammer, when BER is $10^{-3}$.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.544-544
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• 2003

We investigated the inhibitory effect of whitening materials with growth factor or alone on melanomas derived from Human (B-16) and mouse (SK-MEL-31) using melanin content. Melanin content was determined by the absorbance value at 470nm per cells. we used the growth factors known as activators of Adenylate cyclase, Protein kinase C and tyrosine kinase pathway separately. In addition, we compared the action of UV-induced with non-biological growth factor with whitening materials in melanomas derived from Human and mouse. The results showed that the aspect of inhibitory effect of whitening materials on B16 and SK-MEL-31 was not different. And, the action of each growth factor involved in the differentiation and proliferation of melanoma on the inhibition of melanogenesis in B-16 and SK-MEL-31 using whitening agents showed no difference. Also, The action of UV -induced and non-biological growth factors didn't exhibit different pattern on the effect of whitening agent in B-16 and SK-MEL-31.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.388-393
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• 2013

Previously, we have reported that lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, increased melanin synthesis through intracellular $Ca^{2+}$ release in B16 cells. In this study we investigated the possible involvement of nitric oxide (NO) in the mechanism of lovastatin-induced melanogenesis. Lovastatin elevated NO formation in a dose-dependent manner. Treatment with mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), precursors of cholesterol, did not significantly alter the lovastatin-induced NO production, suggesting that inhibition of cholesterol metabolism may not be involved in the mechanism of this action of lovastatin. Both NO formation and melanogenesis induced by lovastatin was significantly suppressed by treatment with $N^G$-nitro-L-arginine methyl ester (L-NAME) and 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylinidazoline-1-oxyl-3-oxide (cPTIO), an inhibitor of NO synthase and a NO scavenger, respectively. The lovastatin-induced NO production was significantly affected not by EGTA, an extracellular $Ca^{2+}$ chelator, but by an intracellular $Ca^{2+}$ chelator (BAPTA/AM) and intracellular $Ca^{2+}$ release blockers (dantrolene and TMB-8). Taken together, these results suggest that lovastatin may induce melanogenesis through NO formation mediated by intracellular $Ca^{2+}$ release in B16 cells. These results further suggest that lovastatin may be a good candidate for the therapeutic application of various hypopigmentation disorders.