Displacement of C4-hydrocarbon molecules adsorbed on platinum

A special technique has been used in an attempt to determine the nature and the amount of the C4-hydrocarbons desorbed by displacement with "poisons" (CO, CS2) from the "active" sites of a platinum on asbestos hydrogenation catalyst. The "active" area of the catalyst determined in this way is found to decrease with increasing adsorption of the poison molecules, and is approximately related in the expected manner to the observed catalytic activity for butene hydrogenation. The likely nature of the adsorbed hydrocarbon species is discussed.Peer reviewed: YesNRC publication: Ye

Endothelial cell response to narrow diameter nylon tubes exhibiting internal nanotopography

The use of three dimensional scaffolds in tissue engineering is well reported, as is the exploitation of nanotopography to influence cell response. To date, due to fabrication limitations, the combination of these two has experienced limited research. This paper reports on the use of polymer demixing, a rapid and cheap nanofabrication method, to create a defined nanotopography in 0.5mm diameter nylon tubes. Results indicate that the resultant nano-island topography reduced endothelial cell adhesion and spreading, strongly influenced cell morphology, and appeared to increase endocytic activity. The use of such constructs that boast topographical cues have great potential in tissue and cell engineering studies for future clinical use, in particular with respect to conduits and stents

Cell response to nano-islands produced by polymer demixing: a brief review

This review looks at the present literature available regarding cell response to nano-islands produced by nanotopography. Polymer demixing is a chemical method of fabricating large areas of nanotopography quickly and cheaply, making it ideal for cell testing and thus allowing it to be one of the first well-researched methods in cell engineering. The review shows that cells respond strongly to the islands (cell types observed include endothelial cells, fibroblasts, osteoblasts, leucocytes and platelets). Such changes include differences in adhesion, growth, gene expression and morphology