• Journal of Ginseng Research
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• v.30 no.2
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• pp.64-69
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• 2006

Gap junctional channels, allowing rapid intercellular communication and synchronization of coupled cell activities, play crucial roles in many signaling processes, including a variety of cell activities. Consequently, a modulation of the gap junctional intercellular communication (GJIC) should be a potential pharmacological target. In the present, the GJIC of a epithelial-derived rat mammary cells (BICR-M1Rk) was assessed in the presence of ginseng saponin, by using an established method of scrape-loading dye transfer assay. The transfer of Lucifer yellow (diameter: 1.2 nm) among the neighboring BICR-M1Rk cells, in which connexin43 (Cx43) is a major gap junction channel-forming protein, was significantly retarded at a concentration of $10{\mu}g/ml$ ginseng saponin. By using both methods of RT-PCR and Western blotting, it was demonstrated that ginseng saponin modulated neither the mRNA synthesis of Cx43 nor the translational process of Cx43. This ginseng saponin-induced modification of GJIC was a similar phenomenon observed under the $\beta$-glycyrrhetinic acid treatment, a well-known gap junction channel blocker. Taken together, it is reasonable to conclude that the ginseng saponin inhibits GJIC only by modulating the gating property of gap junction channels.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.477-482
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• 2011

There are accumulating evidences suggesting that connexin (Cx), a gap junction channel-forming protein, acts as a growth suppressor in various cancer cells, and this effect is attributeed to the gap junction-mediated intercellular communication (GJIC). In order to characterize the relationship between the growth-arresting activity of Cx26 and its cytoplasmic localizations after expression, we linked a nuclear export signal (NES) sequence to Cx26 cDNA before transfecting into a rat breast cancer cell line. A confocal fluorescent microscopic observation revealed that the insertion of NES minimized the nuclear expression of Cx26, and increased its cytoplasmic expression, including plasma membrane junctions. Total cell counting and BrdUrd-labeling experiments showed that the growth of the breast cancer cells was inhibited by 74% upon transfection of Cx26-NES, whereas only 9% inhibition was observed with only Cx26 cDNA.

• Current Photovoltaic Research
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• v.7 no.3
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• pp.76-84
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• 2019

Silicon heterojunction solar cells (SHJ) have dominated the photovoltaic market up till now but their conversion performance is practically limited to around 26% compared with the theoretical efficiency limit of 29.4%. A silicon based multi-junction devices are expected to overcome this limitation. In this report, we briefly review the state-of-art characteristic of wide-gap materials which has played a role as top sub-cells in silicon based multi-junction solar cells. In addition, we indicate significantly practical challenges and key issues of these multi-junction combination. Finally, we focus to some characteristics of III-V/c-Si tandem configuration which are reaching highly record performance in multi-junction silicon solar cells.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.649-656
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• 2003

We have a cultured method to grow rat mammary epithelial cells (RMEC) for 1 to 14 days in 1:1 mixture of Dulbecco's Modified Eagle Medium: Nutrient and F-12 (DMEM/F-12) containing 10% fetal bovine serum (FBS), human EGF, insulin, hydrocortisone, human transferrin and $17{\beta}$-estradiol in vitro. We were able to isolate and distinguish two cell types, luminal epithelial cells and myoepithelial cells, from primary clutures of RMEC. Immunocytochemical stains were used to distingusih luminal epithelial cells and myoepithelial cells. Peanut lectin (PNA) was stained in most alveolar epithelail cells and luminal epithelial cells of rats, while Thy-1.1, a maker of potential rat mammary myoepithelial cells, was expressed in myoepithelial cells in the rat. Also, we examined the expression patterns of three types of gap junction proteins, connexin 26 ($C{\times}26$), connexins 32 ($C{\times}32$) and connexin 43 ($C{\times}43$) by immunocytochemistry and western blot analysis. In the cell types, the results show that at the early stage of culture, luminal epithelial cells were increased and these cells were surrounded by myoepithelial cells. At the late stage of culture, luminal epithelial cells were decreased, in contrast myoepithelial cells were increased. In the expression pattern of gap junction, $C{\times}26$ maintained it's expression until day 3, but afterwards gradually decreased in intensity. Expression of $C{\times}32$ remained until day 5, then decreased slightly. $C{\times}43$ gradually increased untill the middle time of culture then decreased in intensity. These results suggest that connexins may be important for the control of growth in rat mammary epithelial cell types.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.833-836
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• 2005

Nano-gap trench is fabricated by the novel electrochemical etching technique using forward biased PN junction formed at the backside of the wafer. PN junction is formed using boron nitride wafer and the concentration of the boron doping is the high value of $1{\times}10^{19}$ $cm^{-3}$. The electro-chemical etching is performed in the 5% HF solution under the forward bias voltage of $1{\sim}2V$. The relationship between the etch rate of the trench and the voltage of the forward bias is investigated and the dependence of the gap for the voltage also examined. The etch rate increase from 0.027 ${\mu}m/min$ to 0.031 ${\mu}m/min$ as the value of the applied voltage increase from 1V to 2V, but the the gap is kept constant value of 40 nm.

• Current Photovoltaic Research
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• v.2 no.2
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• pp.41-47
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• 2014

Extensive investigation on silicon based thin film reveals a wide range of film characteristics, from low optical gap to high optical gap, from amorphous to micro-crystalline silicon etc. Fabrication of single junction, tandem and triple junction solar cell with suitable materials, indicate that fabrication of solar cell of a relatively moderate efficiency is possible with a better light induced stability. Due to these investigations, various competing materials like wide band gap silicon carbide and silicon oxide, low band gap micro-crystalline silicon and silicon germanium etc were also prepared and applied to the solar cells. Such a multi-junction solar cell can be a technologically promising photo-voltaic device, as the external quantum efficiency of such a cell covers a wider spectral range.

• Progress in Medical Physics
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• v.17 no.4
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• pp.252-259
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• 2006

Gap junctions are distributed within various cells and function as electrical synapses by freely exchanging small molecules. In the retina, the practical role of gap junctions in an animal's motion detection has not been investigated very much. In this study, optometer response (OMR) was used to Investigate the effects of drugs which modulate electrical synapses between retinal ceils. An Injection of carbenoxolone, 8-Br-cAMP, sodium nitroprusside (SNP) or 8-Br-cGMP decreased goldfish's OMR in both light and dark conditions. In light conditions, an intravitreal injection of dopamine, SKF-38393 or eticlopride decreased OMR and that of SCH-23390 increased it. In dark conditions, the injections produced opposite results: dopamine, SKF-38393 and eticlopride increased OMR and SCH-23390 caused OMR to decrease. These results indicate that gap junctions between retinal cells have an Important role in goldfish's motion detection.

• Progress in Superconductivity
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• v.4 no.1
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• pp.64-67
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• 2002

The attenuation of millimeter waves (70-100 ㎓) propagating along Josephson Junction stripline had been measured by pattern recognition near gap voltage and proximity current bump. Test series arrays of 2000, 3000, and 4000 Josephson junctions with the area of $12\mu\textrm{m}$$\times$ $38\mu\textrm{m}$ had two sub-arrays with 50 Junctions at both ends. The arrays were fabricated with and without applying a plasma nitridation process to Nb ground plane. The effects of a nitridationprocess measured by the pattern recognition near gap voltage and proximity current bump were about 1.3-1.7 ㏈ and 1.6-1.8 ㏈, respectively. This means that the last sub-arrays with a nitridation process receive 26-34% more power than those without a nitridation process.

• Genomics & Informatics
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• v.8 no.2
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• pp.70-75
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• 2010

Asp66his, Asp54Lys, and Asp50Asn are mutations in connexin 26 that are observed in the clinic and give rise to autosomal dominant syndromes. They are the result of point mutations in the human gap junction ${\beta}-2$ gene. In order to investigate the structural mechanism of Bart-Pumphrey Syndrome, Keratitis-Ichthyosis-Deafness Syndrome, and Vohwinkel Syndrome, homology modeling was carried out. Asp66 has direct contact with Asn62 by two hydrogen bonds in the wild-type protein, and in Asp66His, the biggest change observed is a tremendous energy increase caused by hydrogen bond breakage to Asn62. Shifts in the side chain and new hydrogen bond formation are observed for Lys54 compared to the wild-type protein (Asn54) and result in closer contact to Val84. Asp50Asn causes a significant decrease in bond energy, and residual charge reversal repels the ion and metabolites and, hence, inhibits their transportation. Such perturbations are likely to be a factor contributing to abnormal functioning of ion channels, resulting cell death and disease.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.335-336
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• 2009