• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.635-644
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• 2019

The aim of this study was to investigate whitening effect of combination between arbutine and oil soluble licorice extract. Inhibitory effects of arbutin and oil soluble licorice extract against tyrosinase activity and melanogenesis in B16 melanoma cells were assessed in vitro to determine whitening effect. MTT assay with B16 melanoma cells showed that mixture (arbutin and oil soluble) was not each concentration. Both oil soluble licorice extract and arbutin induced dose-dependent inhibition of mushroom tyrosinase activity. Various concentrations (oil soluble extract : arbutin = 1:1. 1:1.5, 1:2, 1:2.5, 1:5) of mixtures also significantly inhibited tyrosinase activity in B16 melanoma cells by 40-51%. In addition, the mixtures reduced the melanin contents of B16 melanoma cells by more than 50% at each concentration. These results suggest that mixtures of arbutin and oil soluble licorice extract are very effective whitening ingredients.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.447-451
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• 2021

In this study, we discovered for the first time that linarin, a flavonoid compound, enhances melanin biosynthesis in B16F10 cells, and subsequently elucidated the underlying mechanism of linarin-induced melanogenesis. Linarin showed no cytotoxicity at a concentration of 42 μM and significantly increased intracellular tyrosinase activity and melanin content in B16F10 cells. Mechanistic analysis showed that linarin increased the expression of tyrosinase, tyrosinase-related protein 1 (TRP-1), and microphthalmia-associated transcription factor (MITF) that are related to melanogenesis. Moreover, linarin decreased the phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT). Finally, we evaluated the effect of the structure-activity relationship of linarin and its aglycone on melanogenesis. The results indicated that linarin enhances the expression of melanogenic proteins by activating MITF expression via the modulation of mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K), and protein kinase B signaling pathways in B16F10 cells, thereby enhancing melanogenesis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.721-726
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• 2003

This paper present a waveguide slot 16${\times}$16 assay antenna with diaphragms for 38 GHz frequency band. Diaphragms are used to control the impedance and to minimize the return loss of the structure. A 20 dB Chebyshev array of 16 waveguide slots has been designed by optimizing the positions and sizes of the diaphragms. A serial feeding system with $\pi$- and T-junction power dividers has also designed to get a 20 dB Chebyshev power distribution. A 16${\times}$16 slot array was designed for a Fixed Wireless Access System at 38 GHz frequency band, manufactured using a computer controlled milling technique, and measured for the return -19 dB and the frequency band of 740 MHz.

• YAKHAK HOEJI
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• v.47 no.1
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• pp.25-30
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• 2003

This study is performed to investigate the effects of citrus essential oils on melanin production in B16 melanoma cells. Five kinds of citrus essential oils (Bergamot, Grapefruit, Lemon, Mandarin, Petigrain) did not have any influence on DPPH radical scavenger activity, cell growth and cytotoxicity in B16 melanoma cells. Both mandarin and petigrain essential oils dose-dependently inhibited purified tyrosinase activity, but bergamot did not. In 1$\mu$M MSH-stimulated B16 melanoma cells, all of 5 citrus essential oils inhibited melanin production in a dose dependent manner. From the above results, it is possible that citrus essential oils may be developed to be an anti-melanogenesis agent on the basis of their inhibitory effect on MSH-induced melanin production.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.2
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• pp.268-277
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• 2001

In this paper, the system performance with the convolution code using a Viterbi decoding and the one tap LMS equalizer applied to the OFDM system, which is suitable for IEEE 802.1la wireless LAN in indoor wireless channel, is analyzed through computer simulation. Indoor wireless channel is modeled as Rician fading channel, and QPSK and 16QAM scheme are used for subchannel modulation. In Rician fading channel with the power ratio of the direct path signal to the scattered signals, K=5 dB, BER of $10^{-4}$ is satisfied if the SNRs of the QPSK/OFDM and the 16QAM/OFDM are 8.6 dB and 19.2 dB in hard decision and 5.3 dB and 9.8 dB in soft decision, respectively. Compared with convolution code scheme, it is observed that 16QAM/OFDM system with the one tap LMS equalizer has the performance improvement of 8.6 dB and 2 dB in hard decision and soft decision, respectively.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.1997-2006
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• 2015

Ginsenoside Rg3 is a bioactive ginseng constituent that has been reported to have diverse pathological and physiological effects, including anti-inflammatory and anti-metastatic activities. Metastasis is one of the most important factors involved in patients with melanoma. However, the molecular mechanism underlying the anti-metastatic activities of Rg3 in malignant melanoma cancer has not been fully elucidated. In this study, we have evaluated that Rg3 effectively inhibits metastasis of B16F10 melanoma cancer cells. We found that Rg3 significantly suppresses the migration, invasion, wound healing, and colony-forming abilities of B16F10 cells in a dose-dependent manner. Mechanistically, we demonstrate that Rg3 suppresses B16F10 cell metastasis by inhibiting MMP-13 expression. These results indicate that Rg3 suppresses the metastasis of B16F10 mouse melanoma cancer cells via MMP-13 regulation. Importantly, MMP-13 downregulation may influence the migration and invasion capabilities of melanoma cells and has been correlated with melanoma progression. Therefore, Rg3 is a potential therapeutic candidate that could be used to treat patients with metastatic melanoma.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.75-80
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• 2002

Quercetin is one of the bioflavonoid compounds and has multiple biological effects such as antioxidant and effective anti-inflammatory agent. Melanin has an important role in protecting human skin from the damaging effects of ultra-violet W) radiation. We studied the effect of quercetin on proliferation of B16/F10 melanoma cells. After 48h treatment of cells with quercetin, the cells exhibited a dose-dependent inhibition in their proliferation without apoptosis. Therefore, the decrease in cell numbers may be due to cell growth arrest, not due to cell death by cytotoxicity. We also investigated the effect of quercetin on melanogenesis of this cells. B16/F10 melanoma cells were grown for 48h in the presence of 0.01~50$\mu\textrm{g}$/ml quercetin and the total melanin contents were measured. Quercetin stimulated melanization of the cells in low concentrations (0.01~20$\mu\textrm{g}$/ml), whereas it inhibited melanization in high concentrations (30~50$\mu\textrm{g}$/ml). It was observed that quercetin differently regulates melanogenesis of B16/F10 melanoma cells dependent on its concentrations.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.268-274
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• 2011

Anabaena (Cyanobacteria, Nostocales) are important for water quality controls, because they are often responsible for freshwater green tides; moreover, some species are reported to produce hepatotoxin. In this study, we sequenced RNA polymerase beta subunit (rpoB) gene of Anabaena, and evaluated their sequences for the potential use of a molecular taxonomic marker in this taxon. Anabaena rpoB showed low DNA similarity and high genetic divergences when compared those of 16S rRNA, and the molecular differences were statistically significant (Student t-test, p<0.01). Parsimony analyses showed the rpoB gene evolves 4.8-fold faster than 16S rRNA. In addition, phylogeny of the rpoB gene separated each Anabaena strain more clearly compared with a 16S rRNA tree. These results suggest that the rpoB gene is a useful marker for the molecular phylogenetics and the species discrimination of Anabaena.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.635-642
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• 2000

We have been derived theoretically the SER's and CLP's of Wireless ATM (WATM) cells employing an OFDM/16QAM modulation scheme in wireless channel modeled as a frequency selective Rayleigh fading channel. The amount of the performance improvement of WATM- OFDM/16QAM systems adopting various coding techniques has been evaluated. In frequency selective Rayleigh fading channel, considering CLP : $10^{-3}$ as a criterion, it is observed that the performance improvement of about 14 dB is obtained in terms of $E_b/N_o$ by employing an OFDM scheme. It is also confirmed that convolutional coding technique gives better performance than the other coding techniques. Especially, when the convolutional codes are adopted to WATM-OFDM/16QAM systems, voice transmission services are sufficiently available with 5 dB of $E_b/N_o$.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.3 no.1
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• pp.85-98
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• 1997

Oriental medicine as a candidate for effective cancer treatment recently gain positive concerns in fields of therapeutic oncology. that is why some herbal medicines have been empirically safer in toxicity than anticancer drugs used in western medicine, and to show excellent therapeutic efficacy in human trial. Thus, these effects by clinically applied-herbs have not yet fully demonstrated in experimental tumor model. This study was initiated to evaluate the antitumor effect of Insambaekhaptang as candidate of antitumor-herbal agent against B16 melanoma metastasized into C57BL/6 mice lung. In experiment to test whether Insambaekhaptang can directly kill cancer cells in vitro or not, Insambaekhaptang showed direct killing action in concentration or higher against B16 melanoma cells using MTT assay, and showed lower IC50. Another experiment to know whether Insambaekhaptang can inhibit growth and metastasis of cancer cell or not, Insambaekhaptang significantly inhibited Solid tumor by intraperiperal injected-melanoma and lung metastasis induced by intravenous injected-melanoma in inbred C57BL/6 mice. When quantitative survival time increasing, we could obtain results that increased 113% in treated by Insambaekhaptang. These results show that Insambaekhaptang can inhibit growth of B16 melanoma cells through various biological mechanisms.