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The effect of high‐temperature pretreatment in the presence of steam on NO conversion of protonated cobalt‐incorporated silicate
having MFI structure (H‐Co‐silicate) and copper‐ion‐exchanged MFI‐type zeolite (Cu/H‐ZSM‐5) was studied. The activity of Cu/H‐ZSM‐5
decreased with an increase of pretreatment temperature. In contrast with Cu/H‐ZSM‐5, the activity of H‐Co‐silicate for NO
removal increased with the pretreatment temperature. As for H‐Co‐silicate, the pretreatment at 1000°C was the optimum condition to enhance the conversion that was four times higher than that without pretreatment. The destruction
of framework and loss of cobalt species were not observed after the pretreatment. Some parts of cobalt species migrated from
the framework and became active sites that enhance the activity for NO removal.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Thongchai Nuntanaranont Tapanee Promboot Srisurang Sutapreyasri 《Journal of materials science. Materials in medicine》2018,29(3):24
The purpose of this study was to assess and evaluate new bone formation in rabbit marginal mandibular defects using expanded bone marrow-derived osteoprogenitor cells seeded in three-dimensional scaffolds of polycaprolactone/tricalcium phosphate (PCL/TCP). Bone marrow was harvested from the rabbit ilium and rabbit bone marrow-derived osteoprogenitor cells were isolated and expanded in standard culture medium and osteogenic medium supplement. The cells were then seeded into the PCL/TCP scaffolds and the cell/scaffold constructions were implanted into prepared defects in rabbit mandibles. PCL/TCP scaffold alone and autogenous bone graft from the mandible were also implanted into the other prepared defects. The specimens were evaluated at 4 and 8 weeks after the implantation using clinical, radiographic, and histological techniques. The results of the experimental group demonstrated more newly formed bone on the surface and in the pores of the PCL/TCP scaffolds. In addition, the osteoblasts, osteocytes, and new bone trabeculae were identified throughout the defects that were implanted with the cell/scaffold constructions. The PCL/TCP alone group was filled mostly with fibrous cells particularly in the middle region with less bone formation. These results would suggest that the derived osteotoprogenitor cells have the potential to form bone tissue when seeded onto PCL/TCP scaffolds. 相似文献
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