• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 The 6th Congress of the Federation of Asian and Oceanian Physiological Societies
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• pp.102.2-102.2
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• 2006

• 대한전기학회논문지
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• 제45권2호
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• pp.224-229
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• 1996

Performance characteristics of single cell in phosphoric acid fuel cell were studied for various electrode fabrication parameters such as teflon content, electrode structure, thickness of electrocatalyst layer, platinum content and electrode area. The performance of single cell was decided from the measured voltage-current through a load change. The electrode of 40wt.% teflon exhibited high initial performance of single cell, but in the long term operation, the cell performance of 45 wt.% teflon was better. Also the single cell appeared good performance in case of electrodes with duplicate structure, thin electrocatalyst in thickness, more platinum content, and small area. These results of cell performance were discussed as related to the electrolyte flooding, formation of 3 phase boundary area, internal resistance of electrode, and microstructure of electrode.

• Journal of Microbiology and Biotechnology
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• 제28권3호
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• pp.482-490
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• 2018

Candida albicans infections are often problematic to treat owing to antifungal resistance, as such infections are mostly associated with biofilms. The ability of C. albicans to switch from a budding yeast to filamentous hyphae and to adhere to host cells or various surfaces supports biofilm formation. Previously, the ethanol extract from Paeonia lactiflora was reported to inhibit cell wall synthesis and cause depolarization and permeabilization of the cell membrane in C. albicans. In this study, the P. lactiflora extract was found to significantly reduce the initial stage of C. albicans biofilms from 12 clinical isolates by 38.4%. Thus, to assess the action mechanism, the effect of the P. lactiflora extract on the adhesion of C. albicans cells to polystyrene and germ tube formation was investigated using a microscopic analysis. The density of the adherent cells was diminished following incubation with the P. lactiflora extract in an acidic medium. Additionally, the P. lactiflora-treated C. albicans cells were mostly composed of less virulent pseudohyphae, and ruptured debris was found in the serum-containing medium. A quantitative real-time PCR analysis indicated that P. lactiflora downregulated the expression of C. albicans hypha-specific genes: ALS3 by 65% (p = 0.004), ECE1 by 34.9% (p = 0.001), HWP1 by 29.2% (p = 0.002), and SAP1 by 37.5% (p = 0.001), matching the microscopic analysis of the P. lactiflora action on biofilm formation. Therefore, the current findings demonstrate that the P. lactiflora ethanol extract is effective in inhibiting C. albicans biofilms in vitro, suggesting its therapeutic potential for the treatment of biofilm-associated infections.

• 한국어병학회지
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• 제9권1호
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• pp.95-109
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• 1996

잉어의 순환혈액 림프구의 기능적 분화 유무를 조사하기 위해 포유류를 기준으로한 T 림프구 또는 B 림프구 mitogen인 Con A, PHA 및 LPS와 비특이적 면역 증강제로 Mycobacterium bovis의 약독 균주인 BCG를 각각 잉어, Cyprinus carpio의 복강 내로 주사한 후 시간 경과별 순환혈액 림프구의 수적인 변화와 DNA량의 변화를 조사하고 로젯형성 반응을 실시하였다. mitogen 투여 결과 림프구수와 DNA량 모두 대조구에 비해 증가하였다. mitogen 투여 후 1주와 2주째 최고치에 도달하였으며 BCG와 Con A 투여구가 PHA나 LPS 투여구에 비해 자극 효과가 장기간 지속되었다. 또, 동일한 mitogen의 반복 투여에 비해 T cell과 B cell mitogen을 교차 투여한 실험구의 림프구 자극 효과가 높게 나타났으며, 로젯형성 반응 결과 BCG와 PHA 반복 투여구의 로젯형성 세포수가 가장 높게 나타난 것으로 보아 잉어의 순환혈액내에 기능적으로 분화된 서로 다른 림프구가 존재한다고 사료된다.

• Korean Chemical Engineering Research
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• 제47권4호
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• pp.441-445
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• 2009

고분자전해질 막의 전기화학적 열화에 미치는 온도의 영향에 대해 연구하였다. 가속 열화 조건(OCV, anode 무가습, cathode 65% RH)에서 셀 온도를 변화시켜 144시간 운전한 후 셀 성능은 12에서 35%까지 감소하였다. 이러한 성능 감소는 FER(Fluoride Emission Rate) 측정에서 알 수 있듯이 과산화수소 혹은 산소라디칼(${\cdot}OH$, $HO_2{\cdot}$)의 공격에 의한 막의 열화에 따른 것으로 라디칼 형성을 위한 가스 crossover의 증가를 가져왔다. 전극에서의 라디칼 생성은 ESR로 확인하였다. 고분자막 열화의 온도 의존성을 나타내는 Arrhenius plot에 얻어진 활성화 에너지 값은 66.2 kJ/mol이었다. 셀 작동온도 증가는 라디칼 형성속도와 라디칼이 막을 공격하는 반응 속도뿐 아니라 가스 crossover 속도도 증가시켜 막 열화를 가속화시켰다.

• Journal of Periodontal and Implant Science
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• 제34권4호
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• pp.791-805
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• 2004

The purpose of this study was to evaluate the effects of DFPR on differentiation of mouse calvarial cell in vitro, to examine the possibility for periodontal regeneration. $10{\mu}g/ml$ of DFPR was used as experimental concentration. osteogenic medium only was assigned as control, Experimental 1 was supplemented with 10nM dexamethasone, Experimental 2 with $10{\mu}g/ml$ DFPR and Experimental 3 with l0nM dexamethasone + $10{\mu}g/ml$ DFPR. cellular activity was evaluated by MTT method at 8, 12, 16 days, expression of mRNA of ALP, osteopontin, osteocalcin, collagen type-l was detected by RT-PCR method at 4, 8, 12, 16 days of culture. extent of mineralization was observed by Von Kossa staining at 16 day of culture. The results are as follows 1)Any acceleration of differentiation was not observed at expression of differentiation marker, 2) Decrease in expression of extracelluar matrix and in bone nodule formation was observed The results suggested that DFPR have negative effect on the rate of differentiation on rat calvarial cell, decrease extracelluar matrix formation ,decrease bone nodule formation. Ongoing studies are necessary in order to determine effect of DFPR on periodontal regeneration.

• Journal of Periodontal and Implant Science
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• 제33권2호
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• pp.225-246
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• 2003

Recent study on the enamel matrix derivatives explained on the effects of new bone and new attachment formation in infrabony pocket of periodontal defects. The purpose of this study was to investigate on the biological effects of enamel matrix derivatives to attachment, proliferation and activation of periodontal ligament and osteoblast cells, After treatment of osteoblast and PDL cells with various Emdogain concentration level(0.03${\mu}g$/ml, 3${\mu}g$/ml, 300${\mu}g$/ml), activation of osteogenetic factor, calcified nodule formation and measuring alkaline phosphatase activity(ALP) were performed. 1. Both osteoblast and PDL cell showed increasing initial cell attachment with 300${\mu}g$/ml Emdogain concentration. 2. At the level of 300${\mu}g$/ml, accelerated proliferation of oseoblast and PDL cell was appeared. 3. As Emdogain's concentration increased, increased ALP activation of osteoblast was shown. In case of PDL cell, Emdogain increased ALP activation prominently at the level of 300${\mu}g$/ml. 4. No statistically significant activating change were founded at all of the concentrations of Emdogain on the activating of transcript factor Runx2 for differentiating osteoblast. 5. At the level of 300${\mu}g$/ml, calcified nodule formation was increased prominently to compare with other concentration. These results indicated that Emdogain should activate initial attachment, proliferation and activation, but not on Runx2 activation and can be used for useful tool of the treatment of periodontal tissue regeneration.

• Nutrition Research and Practice
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• 제4권5호
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• pp.356-361
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• 2010

Zinc is an essential trace element required for bone formation, however not much has been clarified yet for its role in osteoblast. We hypothesized that zinc would increase osteogenetic function in osteoblasts. To test this, we investigated whether zinc treatment enhances bone formation by stimulating osteoblast proliferation, bone marker protein alkaline phosphatase activity and collagen synthesis in osteoblastic MC3T3-E1 cells. MC3T3-E1 cells were cultured and treated with various concentrations of zinc (0, 1, 3, 15, 25 uM) along with a normal osteogenic medium (OSM) as control for 1, 5, 10 days. As measured by MTT assay for mitochondrial metabolic activity, cell proliferation was stimulated even at low zinc treatment (1-3 ${\mu}M$) compared to OSM, and it was stimulated in a zinc concentration-dependent manner during 5 and 10 days, with the most pronounced effect at 15 and 25 uM Zn. Cellular (synthesized) alkaline phosphatase (ALP) activity was increased in a zinc concentration-dependent manner, so did medium (secreted) ALP activity. Cellular collagen concentration was increased by zinc as time went by, therefore with the maximum zinc stimulatory effect in 10 days, and medium collagen concentration showed the same pattern even on 1 and 5 day. This zinc stimulatory effect of collagen synthesis was observed in cell matrix collagen staining. The study results imply that zinc can increase osteogenic effect by stimulating cell proliferation, ALP activity and collagen synthesis in osteoblastic cells.

• 식물조직배양학회지
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• 제26권3호
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• pp.219-222
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• 1999

부정아를 유도하기 위하여 발아 7∼10일된 일본 결구상추 2품종과 국내 잎상추 (Lactuca sativa L.)4품종의 하배축 및 자엽절편으로부터 식물체 재분화시스템을 확립하였다. 하배축 및 자엽절편을 BA와 NAA가 조합 처리된 MS 및 SH배지에 치상하여 5주 동안 명배양하였다. 일반적으로 하배축보다는 자엽절편에서, SH 배지보다는 MS 배지에서 배양하였을 때에 부정아 형성률이 높았다. MS배지에 BA는 0.5 ㎎/L, NAA는 0.1∼l ㎎/L로 처리하였을 때에 최고의 부정아 형성률을 보였으며, 품종에 따라 30% ( '만추대청치마')에서 86% 까지의 부정아 형성률을 나타내었다. 형성된 shoot의 95% 이상이 MS 기본배지에서 발근하여 소식물체로 발달하였다.

• Journal of Microbiology
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• 제44권4호
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• pp.447-452
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• 2006

The murine ecotropic retroviral receptor has been demonstrated to function as a mouse cationic amino acid transporter 1(mCAT1), and is comprised of multiple membranespanning domains. Feral mouse (Mus dunni) cells are not susceptible to infection by the ecotropic Moloney murine leukemia virus (MoMLV), although they can be infected by other ecotropic murine leukemia viruses, including Friend MLV and Rauscher MLV. The relative inability of MoMLV to replicate in M. dunni cells has been attributed to two amino acids $(V_{214}\;and\;G_{236})$ located within the third extracellular loop of the M. dunni CAT1 receptor (dCAT1). Via the exchange of the third extracellular loop of the mCAT1 cDNA encoding receptor from the permissive mouse and the corresponding portion of cDNA encoding for the nonpermissive M. dunni receptor, we have identified the most critical amino acid residue, which is a glycine located at position 236 within the third extracellular loop of dCAT1. We also attempted to determine the role of the third extracellular loop of the M. dunni CAT1 receptor with regard to the formation of the syncytium. The relationship between dCAT1 and virus-induced syncytia was suggested initially by our previous identification of two MLV isolates (S82F in Moloney and S84A in Friend MLV), both of which are uniquely cytopathic in M. dunni cells. In an attempt to determine the relationship existing between dCAT1 and the virally-induced syncytia, we infected 293-dCAT1 or chimeric dCAT1 cells with the S82F pseudotype virus. The S82F pseudotype virus did not induce the formation of syncytia, but did show increased susceptibility to 293 cells expressing dCATl. The results of our study indicate that S82F-induced syncytium formation may be the result of cell-cell fusion, but not virus-cell fusion.