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Sol-gel법을 이용한 미세공 실리카 세라믹의 기공구조 변화에 관한 연구
이진휘,연만형,정은정,박노혁 서울産業大學校 1996 논문집 Vol.43 No.1
솔-젤법에 의하여 제조된 미세공 실리카 세라믹에 대하여 N₂-adsorption isotherm 및 TEM에 의하여 기공구조 변화를 조사하였다. Group 1, 2 및 3의 경우 물의 양이 각각 11, 5.5 및 3.8mole까지는 급격히 surface area의 증가를 보이다가 그 이후에는 완만한 상승을 보이는데, 이것은 앞의 실험에서 보인[4.5]gelation time 및 FT-IR의 실험결과와 일치하는 것이다. 서로 다른 물의 양에 대하여 BET surface area와 Cumulative surface area의 차이가 Group 1서 Group 3으로 옮아감에 따라 커지는 것은 용매의 양은 감소하는 반면 TEOS의 양 증가로 인하여 물과 TEOS의 반응이 원활하지 못한 결과로 덜 발달된 polymer에 기인한 작은 particle에 의하여 형성된 작은 기공들에 기인한 것으로 사료된다. 이와같은 기공구조는 TEM의 결과에 의하여 확인할 수 있다. Group A에서 E쪽으로 갈수록 물의 양의 증가에 기인하여 surface area는 증가하며, Group a에서 d쪽으로 갈수록 물의 양의 감소에 기인하여 surface area는 감소한다. N₂-adsorption isotherm and TEM were used to investigate the micro-porous silica ceramic prepared by sol-gel process to find the structural changes of pores. In the case of Group 1, 2 and 3, the drift of the surface area increased steeply till the amount of water 11, 5.5 and 3.8 moles individually and after that showed increased smoothly. It is the same results as the gelation time and the FT-IR[4.5]. It is the reason that the differences of BET and Cumulative surface area become larger proportionally as moving from Group 3 that the reaction of water and TEOS is less active, caused by using decreased quantity of water but increased TEOS, and therefore the smaller pores by the smaller particles were formed. It was identified by TEM. The surface area is increased by the increased water as moving from Group A to Group E, and decreased by the decreased water as moving from a to e.
Neuron Differentiation Condition of Human Adipose Tissue Derived Stem Cells
Eun Hyung Noh,Hyo Young Park,Eun Young Kim,Se Pill Park 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1
Stem cell therapy is undoubtedly the most promising therapeutic approach for neurological disorders. Adipose tissue is ubiquitous and it can be easily harvested in large quantities under local anesthesia with little patient discomfort, making adipose tissue into the ideal large-scale source for research on clinical applications. In this study we monitored the neuronal cell differentiation potential of human adipocyte in the following condition; i) N2 medium containing 200 uM ascorbic acid (AA) and/or 10 uM flavonoid (F) and ⅱ) N2 medium containing AA and/or 10 ng/ml brain derived neurotrophic factor (BDNF) and/or, 200 ng/ml sonic hedgehog (SHH) plus 100 ng/ml fibroblast growth factor (FGF) 8. Adipose stem cells were cultured in above described differentiation condition for three weeks. RT-PCR analysis demonstrated that the mRNA levels of neuronal cell markers in differentiated adipose stem cells. Under the culture condition using N2 medium containing AA, the expression level of nestin (neural progenitor marker) m- RNA was high in all groups, while those of Neuro D, and LEP and FABP4 (adipocyte marker) mRNA were significantly decreased. Also, the addition of BDNF or SHH+FGF8 in N2 medium containing AA enhanced the neural cell differentiation from adipose stem cells, the expression level of Map2 (mature neuron) mRNA was increased, and that of TH (dopaminergic neuron marker) mRNA was high. In addition, we confirmed that the flavonoid addition has effect on the increase of Map2 expression. These results demonstrate that our designed culture condition has effect on the neural cell differentiation of adipose stem cells and this stimulatory effect may be further enhanced by transplantation.