• Molecules and Cells
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• v.39 no.5
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• pp.403-409
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• 2016

NME1 is a well-known metastasis suppressor which has been reported to be downregulated in some highly aggressive cancer cells. Although most studies have focused on NME1, the NME1 gene also encodes the protein (NME1L) containing N-terminal 25 extra amino acids by alternative splicing. According to previous studies, NME1L has potent anti-metastatic activity, in comparison with NME1, by interacting with $IKK{\beta}$ and regulating its activity. In the present study, we tried to define the role of the N-terminal 25 amino acids of NME1L in $NF-{\kappa}B$ activation signaling. Unfortunately, the sequence itself did not interact with $IKK{\beta}$, suggesting that it may be not enough to constitute the functional structure. Further construction of NME1L fragments and biochemical analysis revealed that N-terminal 84 residues constitute minimal structure for homodimerization, $IKK{\beta}$ interaction and regulation of $NF-{\kappa}B$ signaling. The inhibitory effect of the fragment on cancer cell migration and $NF-{\kappa}B$-stimulated gene expression was equivalent to that of whole NME1L. The data suggest that the N-terminal 84 residues may be a core region for the anti-metastatic activity of NME1L. Based on this result, further structural analysis of the binding between NME1L and $IKK{\beta}$ may help in understanding the anti-metastatic activity of NME1L and provide direction to NME1L and $IKK{\beta}$-related anti-cancer drug design.

• IMMUNE NETWORK
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• v.5 no.1
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• pp.45-49
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• 2005

Background: Inflammation in the brain has known to be associated with the development of a various neurological diseases. The hallmark of neuro-inflammation is the activation of microglia, brain macrophage. Pro-inflammatory compounds including nitric oxide (NO) are the main cause of neuro-degenerative disease such as Alzheimer's disease (AD) which is resulted in cell death. Among those pro-inflammatory compounds, NO contributes to the cell death by directly or indirectly. Methods: In the study, we examined whether ursodeoxycholic acid (UDCA), a non-toxic hydrophilic bile acid, inhibits the NO production by a direct method using Griess reagent and by RT-PCR in the gene expression of inducible nitric oxide synthase (iNOS). In signal transduction, we also examined the NF-${\kappa}B$ (p65/p50), IKK, and I ${\kappa}B$, which are associated with the expression of iNOS gene using western blots. Results: In the present study, we found that UDCA effectively inhibited NO production in BV-2 microglial cell, and NF-${\kappa}B$ activation was reduced by suppressing IKK gene expression and by increasing the I${\kappa}B$ in cytosol comparing those to the positive control LPS. Conclusion: Taken together, these data suggested that UDCA may playa crucial role in inhibiting the NO production and the results imply that UDCA suppresses a cue signal of the microglial activation via stimulators, such as ${\beta}$-amyloid peptides which are known to stimulate microglia in AD pathogenesis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.75-82
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• 2000

In this Paper, a new type of feedforward linearizer using a delay line which controls the phase characteristics of the correction amplifier block is proposed. The extra delay line provides the control-ability of IM signals so that the IM rejection is accomplished without the conventional pilot tone. The error signal loop consists of several key components such as phase shifter and attenuator, subtractor. These key components are replaced by new designs in order to obtain better linearization characteristics without the pilot tone generator which is indispensable in the conventional linearizer designs. The proposed linearizer was designed at Korean PCS band and combined with 35W HPA manufactured by KMW inc., and tested with two-tone signals separated 0.6MHz apart at the center frequency of 1855MHz. The experimental results show C/l improvement by 16.9 ~ 24.6 dB over 15 dB dynamic range(30 ~45 dBm) which gave IMD of 58.5~63.2 dBc for the designed LPA.

• Journal of Radiation Protection and Research
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• v.32 no.1
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• pp.21-26
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• 2007

This study is performed to evaluate the dose rate and to analyze the dose distribution of the gamma irradiation facility (IR-221) by using a Monte Calro simulation, which is helpful of upgrading the radiation processing qualification. Monte Cairo simulation is performed by MCNP4B code. Dose rates were measured at total 369 points with alanine dosimeters to compare the calculation results and the measurements data. The results have shown that the MCNP4B code is very useful to determine the dose distribution of the IR-221 gamma irradiation facility, as the calculation dose rate is within about ${\pm}5%$ of the measurement data. Dosimetry about the gamma irradiation facility usually needs enormous manpower and time. However Monte Cairo calculation method can reduce the tedious dosimetry jobs and improve the irradiation processing qualification, which will probably contribute to obtain the reliability of the irradiation products.

• Korean Journal of Ichthyology
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• v.12 no.4
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• pp.223-229
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• 2000

Phylogenetic relationships between 8 species Korean loaches (Cobitidae) were investigated by comparing mitochondrial cytochrome b gene sequences. However our results are in accordance with finding observed using other morphological studies, new interesting interspecific variation in Korean loaches were found. Orthrias and Lefua appeared to be paraphyletic in Cobitidae observed. Their sequence divergence value was agreed with interfamilic sequence divergences between Cobitidae and Cyprinidae ranged from 0.184 to 0.272. Otherwise, the present results support that two species of Iksookimia and Cobitis melanoleuca were early diverged respectively. And another remarkable result was sequence divergence between Misgurnus anguillicaudatus from China and M. anguillicaudatus from Yongdok, Korea. That was 0.099, which was interspecific value. Also the phylogenetic location of some Iksookimia species was suggested as the cobitid intergeneric hybrid origin.

• Journal of Broadcast Engineering
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• v.15 no.3
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• pp.414-425
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• 2010

When we implement the single frequency network (SFN) in ATSC terrestrial DTV system, there is an interference problem to DTV receivers due to the use of same frequency channel among transmitters and repeaters. To resolve this problem, it is recommended to adopt the transmitter identification signals in transmitting equipments. In this paper, we analyzed the influence suffered by legacy DTV receivers when the TxID signal is added to the DTV transmitting signals and the results were further verified by computer simulation, laboratory test and field test. The above tests show that if the TxID signal is added to the level of -30dB compared to the original DTV signal, the TOV(Threshold Of Visibility) increment in legacy receivers is about 0.17 dB. It means that we can insert and transmit the TxID signal in ATSC terrestrial DTV system without making the negative effect to the legacy DTV receivers.

• Fisheries and Aquatic Sciences
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• v.21 no.9
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• pp.21.1-21.8
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• 2018

In the present study, we first evaluated the melanin inhibitory effect of four crude 70% ethanol extracts separated from soft corals abundantly growing along the seawaters of Jeju Island, South Korea, including Dendronephthya castanea (DC), Dendronephthya gigantea (DG), Dendronephthya puetteri (DP), and Dendronephthya spinulosa (DS). Among the four ethanol extracts, the ethanol extract of DP (DPE) did not possess any cytotoxic effect on B16F10 cells. However, all other three extracts showed a cytotoxic effect. Also, DPE reduced the melanin content and the cellular tyrosinase activity without cytotoxicity, compared to the ${\alpha}-MSH$-stimulated B16F10 cells. Specifically, DPE downregulated the expression levels of tyrosinase and microphthalmia-associated transcription factor by activating the ERK signaling cascade in ${\alpha}-MSH$-stimulated B16F10 cells. Interestingly, the melanin inhibitory effect of DPE was abolished by the co-treatment of PD98059, an ERK inhibitor. According to these results, we suggest that DPE has whitening capacity with the melanin inhibitory effects by activating ERK signaling and could be used as a potential natural melanin inhibitor for cosmeceutical products.

• Progress in Superconductivity
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• v.7 no.2
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• pp.103-108
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• 2006

We have measured the Hall resistivity (${\rho}_{xy}$) and the longitudinal resistivity (${\rho}_{xy}$) on superconducting $MgB_2$ thin films in extended fields up to 18 T. We found a universal scaling behavior between the Hall resistivity and the longitudinal resistivity, which is independent of the temperature and the magnetic field. At a wide magnetic field region from 1 to 18T, a universal power law of ${\beta}=2.0{\pm}0.1$ in a scaling relation, ${\rho}_{xy}={A{\rho}_{xx}}^{\beta}$, was observed in c-axis-oriented $MgB_2$ thin films. These results can be well interpreted by using recent models.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.209-213
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• 1976

Spinous loaches widely distributed in Korea, are of many color pattern types, but interestingly the crossband B and C-types of these coaches are collected only in the two rivers, the Yeongsan River and the Seomjin River, flowing through the south-western part of Korea. These two types have not only different color pattern, but also different geographical distribution: the B-type is found in the Yeongsan River and the C-typs, in the Seomjin River. But the both types have four common distinctive features, which easily distinguish them from other already known species of this genus: the B and C-types have the similar total length distribution, the same structure of lamina circularis and scales, and the black spots at the back of their opercula. These peculiarities may be explained by studing the history of these two rivers. The author considers that they are once rivers of the same origin located around the Noryeong and the Sobaeg Mountains, and then were eventually separated from each other as the water level or the crust of Korea peninsula changed. Thus, these two types, B and C, of spinous loaches should have been the same species living in the same river, but in the course of time, these two types have taken different color patterns since the separation of two rivers thus making them impossible to cross between these two populations.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.394-400
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• 2012

Contents of soyasaponin group B were compared according to two regions and ten varieties by HPLC. Those compounds were known to be beneficial for health. After soyasaponins were isolated and identified, those isolated compounds were used for HPLC analysis. The contents of soyasaponin were very different by regions but highest in the soybean with black seed coat. It was appeared that environmental difference for soybean growth could strongly change of soyasaponin contents.