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    Boron-rich B-C compounds with high hardness have been recently synthesized by the chemical vapor deposition (CVD) method. In this paper, we present our successful efforts in the selective growth of microstructures of boron-carbon compounds on silicon substrates. This was achieved by combining microfabrication techniques such as maskless lithography and sputter deposition with the CVD technique. Our characterization studies on these B-C microstructures showed that they maintain structural and mechanical properties similar to that of their thin-film counterparts. The methodology presented here paves the way for the development of microstructures for microelectromechanical system (MEMS) applications which require custom hardness and strength properties. These hard B-C microstructures are an excellent choice as support structures in MEMS-based devices. 
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  4. We report a novel and facile organosilane plasma polymerization method designed to improve the surface characteristics of poly(tetrafluoroethylene) (PTFE). We hypothesized that the polymerized silane coating would provide an adhesive surface for endothelial cell proliferation due to a large number of surface hydroxyl groups, while the large polymer networks on the surface of PTFE would hinder platelet attachment. The plasma polymerized PTFE surfaces were then systematically characterized via different analytical techniques such as FTIR, XPS, XRD, Contact angle, and SEM. The key finding of the characterization is the time-dependent deposition of an organosilane layer on the surface of PTFE. This layer was found to provide favorable surface properties to PTFE such as a very high surface oxygen content, high hydrophilicity and improved surface mechanics. Additionally, in vitro cellular studies were conducted to determine the bio-interface properties of the plasma-treated and untreated PTFE. The important results of these experiments were rapid endothelial cell growth and decreased platelet attachment on the plasma-treated PTFE compared to untreated PTFE. Thus, this new surface modification technique could potentially address the current challenges associated with PTFE for blood contact applications, specifically poor endothelial cell growth and risk of thrombosis. 
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  5. For several decades, plasma processing has been employed in the areas of food processing, manufacturing, and agriculture. Plasma processing has also been recognized as greatly beneficial in the field of tissue engineering for the modification of biomaterials. Polyethylene terephthalate (PET) has been employed as a vascular graft material but fails in small diameter applications. In this work, a multifaceted approach combining electrospinning to produce nano- and microscale fibers from PET blended with polybutylene terephthalate (PBT) added for flexibility and plasma modification for enhancing the surface chemistry is demonstrated to be an efficient approach to increase the biocompatibility as evidenced by enhanced fibroblast growth. The analysis of the surface chemistry shows an increase in oxygenated surface functionality, while the bulk analysis shows no significant changes. Thus, an efficient methodology for producing PET/PBT-based grafts that are easily modified with low-temperature plasma and show enhanced biocompatibility for vascular tissue engineering applications is reported. 
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