1,961 research outputs found
An outline of polar spaces: basics and advances
This paper is an extended version of a series of lectures on polar spaces
given during the workshop and conference 'Groups and Geometries', held at the
Indian Statistical Institute in Bangalore in December 2012. The aim of this
paper is to give an overview of the theory of polar spaces focusing on some
research topics related to polar spaces. We survey the fundamental results
about polar spaces starting from classical polar spaces. Then we introduce and
report on the state of the art on the following research topics: polar spaces
of infinite rank, embedding polar spaces in groups and projective embeddings of
dual polar spaces
Thin Polymer Brush Decouples Biomaterial's Micro-/Nano-Topology and Stem Cell Adhesion
Surface morphology and chemistry of polymers used as biomaterials, such as tissue engineering scaffolds, have a strong influence on the adhesion and behavior of human mesenchymal stem cells. Here we studied semicrystalline poly(ε-caprolactone) (PCL) substrate scaffolds, which exhibited a variation of surface morphologies and roughness originating from different spherulitic superstructures. Different substrates were obtained by varying the parameters of the thermal processing, i.e. crystallization conditions. The cells attached to these polymer substrates adopted different morphologies responding to variations in spherulite density and size. In order to decouple substrate topology effects on the cells, sub-100 nm bio-adhesive polymer brush coatings of oligo(ethylene glycol) methacrylates were grafted from PCL and functionalized with fibronectin. On surfaces featuring different surface textures, dense and sub-100 nm thick brush coatings determined the response of cells, irrespective to the underlying topology. Thus, polymer brushes decouple substrate micro-/nano-topology and the adhesion of stem cells
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