• BMB Reports
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• 제45권5호
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• pp.281-286
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• 2012

Osteoclasts are multinucleated cells that are formed by the fusion of pre-fusion osteoclasts (pOCs). The fusion of pOCs is known to be important for osteoclastic bone resorption. Here, we examined the effect of IFN-${\gamma}$ on the fusion of pOCs. IFN-${\gamma}$ greatly increased the fusion of pOCs in a dose-dependent manner. Furthermore, IFN-${\gamma}$ induced pOC fusion even in hydroxyapatite-coated plates used as a substitute for bone. The resorption area of pOCs stimulated with IFN-${\gamma}$ was significantly higher than that of the control cells. IFN-${\gamma}$ induced the expression of dendritic cell-specific transmembrane protein (DC-STAMP), which is responsible for the fusion of pOCs. IFN-${\gamma}$ enhanced DC-STAMP expression in a dose-dependent manner. The mRNA expression of c-Fos and nuclear factor of activated T cells (NFAT) c1 was enhanced in the pOCs treated with IFN-${\gamma}$. Taken together, these results provide a new insight into the novel role of IFN-${\gamma}$ on the fusion of pOCs.

• Natural Product Sciences
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• 제19권4호
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• pp.347-354
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• 2013

Cordyceps militaris, a traditional medicinal mushroom, produces a component compound, cordycepin (3'-deoxyadenosine). Cordycepin has many pharmacological activities including immunological stimulating, anti-cancer, and anti-infection activities. However, the therapeutic mechanism has not yet been elucidated. In this study, we examined the effects of cordycepin on the antigen-presenting function of antigen-presenting cells (APCs). Dendritic cells (DCs) were cultured in the presence of cordycepin and then allowed to phagocytose microspheres containing ovalbumin (OVA). After washing and fixing, the efficacy of OVA peptide presentation by DCs was evaluated using CD8 and CD4 T cells. Also, we confirmed the protein levels of proinflammatory cytokines through RT-PCR and Western blot analysis. Cordycepin decreased both MHC class I and class II-restricted presentation of OVA and suppressed the expression of both MHC molecules and the phagocytic activity toward exogenous OVA. The class II-restricted OVA presentation-regulating activity of cordycepin was also confirmed using mice that had been injected with cordycepin followed by soluble OVA. Furthermore, cordycepin suppressed the mRNA and protein levels of iNOS, COX-2, pro-inflammatory cytokines in a concentration-dependent manner. These results provide an understanding of the mechanism of the T cell response-regulating activity of cordycepin through the inhibition of MHC-restricted antigen presentation in relation to its actions on APCs.

• 산업기술연구
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• 제40권1호
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• pp.7-12
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• 2020

Lithium-ion cells have become the go-to energy source across all applications; however, dendritic growth remains an issue to tackle. While there have been various research conducted and possible solutions offered, there is yet to be one that efficiently rules out the problem without, however, introducing another. This paper seeks to present a fast charging method and system to which lithium-ion batteries are charged while maintaining their lifetime. In the proposed method, various lithium cells are charged under multiple profiles. The parameters of charge profiles that inflict damage to the cell's electrodes are obtained and used as thresholds. Thus, during charging, voltage, current, and temperature are actively controlled under these thresholds. In this way, dendrite formation suppressed charging is achieved, and battery life is maintained. The fast-charging system designed, comprises of a 1.5kW charger, an inbuilt 600W battery pack, and an intelligent BMS with cell balancing technology. The system was also designed to respond to the aging of the battery to provide adequate threshold values. Among other tests conducted by KCTL, the cycle test result showed a capacity drop of only 0.68% after 500 cycles, thereby proving the life maintaining capability of the proposed method and system.

• 전자공학회논문지A
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• 제31A권7호
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• pp.85-94
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• 1994

A high-resolution transmission electron microscopy study of the solid phase crystallization of the amorphous silicon thin films, deposited on SiOS12T at 52$0^{\circ}C$ by low pressure chemical vapor deposition and annealed at 55$0^{\circ}C$ in a dry N$_{2}$ ambient was carried out so that the arrangement of atoms in the crystalline silicon and at the amorphous/crystalline interface of the growing grains could be understood on an atomic level. Results show that circular crystalline silicon nuclei have formed and then the grains grow to an elliptical or dendritic shape. In the interior of all the grains many twins whose{111} coherent boundaries are parallel to the long axes of the grains are observed. From this result, it is concluded that the twins enhance the preferential grain growth in the <112> direction along {111} twin planes. In addition to the twins. many defect such as intrinsic stacking faults, extrinsic stacking faults, and Shockley partial dislocations, which can be formed by the errors in the stacking sequence or by the dissociation of the perfect dislocation are found in the silicon grain. But neither frank partial dislocations which can be formed by the condensation of excess silicon atoms or vacancies and can form stacking fault nor perfect dislocations which can be formed by the plastic deformation are observed. So it is concluded that most defects in the silicon grain are formed by the errors in the stacking sequence during the crystallization process of the amorphous silicon thin films.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.107-107
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• 2002

ADAM은 metalloprotease/disintegrin domain을 가진 transmembrane glycoprotein 으로서 지금까지 30개 이상의 ADAM 및 10개 이상의 ADAMTS 단백질이 알려져 있다. 이들의 기능은 포유동물의 수정시 sperm-egg binding과 fusion, myoblast fusion, integrin과의 결합 등에 직접 관여하거나, TNF-alpha 등의 생체 신호전달물질이 세포로부터 분비될 때에 이들의 구조를 변화시켜 활성화시키는 효소작용, 그리고 dendritic cell differentiation 등에 관여하는 것으로 알려져있다. 그러나 자궁내막 조직에서의 유전자 및 단백질 발현 여부에 관해서는 거의 보고되어 있지 않고 있다. 먼저 RT-PCR 방법을 이용하여 자궁에서 mRNA의 양을 $\beta$-actin의 양에 대하여 상대적으로 측정한 결과, 임신 1일부터 5일까지는 ADAM-9, 10, 17, TS1의 mRNA 경우 거의 비슷하게 발현되었으며 ADAM-8과 15는 3일째, ADAM-12는 2일째와 4일째에 현저하게 증가하였다 임신 6일부터 8일까지의 자궁조직을 각각 embryo가 착상된 곳과 그렇지 않은 곳으로 나누어 조사한 결과 상대적으로 착상이 된 곳에서 mRNA가 많이 발현 되었으며 특히 ADAM-8, 12, 15의 mRNA의 경우 현저한 차이를 보였다. Immunoblotting 방법을 이용하여 임신 1일부터 5일까지의 단백질의 발현 양상을 조사한 결과 임신 ADAM-8은 3일 이후 감소되는 양상을 보였으며 ADAM-9, 15, TS1은 5일째에 증가하는 양상을 보였다. ADAM-10은 2일째 감소하다가 다시 증가하고 ADAM-12, 17은 3, 4일째 증가하다가 5일째 감소하는 상을 보였다. 한편 임신 6일부터 8일까지는 embryo가 착상된 곳이 그렇지 않은 곳보다 조사된 모든 ADAMs 단백질이 상대적으로 많이 발현되는 양상을 보였다. 이러한 결과로 미루어 ADAMs은 임신 초기 착상과정과 임신 단계에 따른 자궁의 조직 재구성에 중요한 역할을 할 것으로 생각된다.

• 소성∙가공
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• 제6권3호
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• pp.239-249
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• 1997

The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular. To optimal net shape forging of semi-solid materials, it is important to investigate for filling phenomena in forging process of arbitrarily shaped dies. To produce a automotive part which has good mechanical property, the filling pattern according to die velocity and solid fraction distribution has to be estimated for arbitrarily shaped dies. Therefore, the estimation of filling characteristic in the forging simulation with arbitrarily shaped dies of semi-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for arbitrarily shaped dies is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process with arbitrarily shaped dies is performed to the isothermal conditions of two dimensional problems. To analysis of forging process by using semi-solid materials, a new stress-strain relationship is described, and forging analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for forging force and filling limitations will be compared to experimental data. The filling simulation of simple products performed with the uniform billet temperature(584$^{\circ}C$) from the induction heating by the commercial package MAGMAsoft. The initial step of computation is the touching of semi-solid material with the end of die gate and the initial concept of proposed system just fit with the capability of MAGMAsoft.

• 대한치과기공학회지
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• 제22권1호
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• pp.69-78
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• 2000

The microstructure and corrosion behavior of commercially dental casting gold alloys were investigated to clarify the effect of burn-out temperature and cooling rate. In the case of water quenching after casting, only the αphase, which is typical dendritic microstructure of golda alloy, was detected. However, the precipitates along the grain boundary were detected only at the slow cooling rate and they increased inversely proportional to the burn-out temperature. This might be due to the time difference which solute atom could diffuse. EPMA and SEM results also demonstrated that the precipitate should be lamellar structure consisted of Ag rich phase(${\alpha}_1$) and Cu rich phase (${\alpha}_2$). In terms of corrosion, the galvanic coupling was formed due to the difference of composition between precipitates and matrix at the slow cooling rate. In the case of water quenching, the critical current density($i_p$) which indicate the degree of corrosion was lowest at $650^{\circ}C$ and below the burnout temperature, $i_p$ increased with it because of the effect of grain boundary segregation. But above the temperature, $i_p$ increased with it. This may be due to the strain field effect by residual thermal stress.

• 대한치과보철학회지
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• 제25권1호
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• pp.303-316
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• 1987

The purpose f this study was to evaluate the effect of resin film thickness on the tensile bond strength and to compare the tensile bond strengths of 4 differently treated metal surfaces. For the experiment, seventy metal specimens were cast with Verabond and divided into I, II, III, groups. The metal specimens in group I were electrolytically etched and cemented with Panavia under finger pressure. Cement film thickness was regulated with metal spacers. The metal specimens in Group II were treated by 4 methods, such as electrolytic etching method, salt-roughened method, EZ-oxisor method , chemical etching method and cemented with Panavia. In group III, electrolytically etched metal specimens were cemented with Hy-Bond. The etched surface of metal specimens and the cement film thickness were examined under the scanning electron microscope. Results were as follows; 1. The tensile bond strength showed no significant difference between $30{\mu}m,\;80{\mu}m,\;130{\mu}m$ film thicknessspecimens. 2. There was no significant difference in the tensile bond strength between the 4 differently treated metal specimens. 3. The tensile bond strength showed significant difference between Panavia and Hy-Bond. 4. Scanning electron microscope photograph revealed that tile interdendritic eutectic was removed in electrolytically etched metal surfaces hilt even dendritic arm was removed in Chemically etched metal surfaces. 5. The metal surfaces which were air-abraded with $50{\mu}m$ aluminum oxide showed roughness and small crack on scanning electron microscope photograph.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.987-991
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• 2013

Aim: To study anti-tumor effects of exosomes from class II transactivator (CIITA) gene transfected CT26 cells. Methods: In this study, we established an MHC class II molecule-expressing murine colon cancer cell line (CT26-CIITA) by transduction of the CIITA gene. Immune effects in vitro and tumor protective results in vivo were tested and monitored. Results: Exosomes from CT26-CIITA cells were found to contain a high level of MHC class II protein. When loaded on dendritic cells (DCs), exosomes from CT26-CIITA cells significantly increased expression of MHC class II molecules, CD86 and CD80, as compared to exosomes from CT26 cells. In vitro assays using co-culture of immunized splenocytes and exosome-loaded DCs demonstrated that CIITA-Exo enhanced splenocyte proliferation and IFN-${\gamma}$ production of CD4+T cells, while inhibiting IL-10 secretion. In addition, compared to exosomes from CT26 cells, CT26-CIITA-derived exosomes induced higher TNF-${\alpha}$ and IL-12 mRNA levels. A mouse tumour preventive model showed that CT26-CIITA derived exosomes significantly inhibited tumour growth in a dose-dependent manner and significantly prolonged the survival time of tumour-bearing mice. Conclusion: Our findings indicate that CT26-CIITA-released exosomes are more efficient to induce anti-tumour immune responses, suggesting a potential role of MHC class II-containing tumour exosomes as cancer vaccine candidates.

• International Journal of Oral Biology
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• 제34권3호
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• pp.131-135
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• 2009

The sublingual locus has recently received great attention as a delivery site for various immunotherapies, including those that induce allergen-specific tolerance, and for vaccines that generate protective immunity. To further understand the immune functions of the human sublingual mucosa, we characterized the distribution of various immunocytes therein by immunohistochemistry. We identified professional antigen presenting cells (APCs), including Langerhans cells (LCs) and macrophages. $CD1a^+$ and $langerin^+$ LCs were further found to be distributed in the basal and supra-basal layers of the epithelium, and macrophages were identified in the lamina propria. HLA-$DR^+$ cells were observed in both the epithelium and the lamina propria, which mirrors the tissue distribution of LCs and macrophages within these tissues. $CD3^+$, $CD4^+$, and $CD8^+$ T cells were found to be distributed along the basal layer of the epithelium and also in the lamina propria. Although B cells, plasma cells, and $Foxp3^+$ regulatory T cells (Tregs) were only occasionally observed in the human sublingual mucosa in the absence of inflammation, they did show enrichment at inflammatory sites. Hence, we have further elucidated the immune cell component distribution in human sublingual mucosa.