Current Issue : January - March Volume : 2013 Issue Number : 1 Articles : 6 Articles
A complex of the induction magnetic field two-way nanotransducers of the different physical values for both the external and\r\nimplantable interfaces in a wide range of arrays are summarized. Implementation of the nanowires allows reliable transducing of\r\nthe biosignals� partials and bringing of carbon nanotubes into circuits leading to examination of the superconducting transition.\r\nNovel sensors are based on the induction magnetic field principle, which causes their interaction with an ambient EM field.\r\nMathematical description of both the signal and mediums defines space embracing of the relevant interfacing devices. As a result,\r\na wide range of the nano-bio-transducers allow both delivering the variety of ionized biosignals and interface the bioEM signals\r\nwith further stages of electronic systems. The space coverage and transducing values properties of the state-of-the-art magnetic\r\ninterfaces are summarized, and directions for their future development are deduced....
We overview the state of the art in the field of safe exposure levels setting for nanomaterials together with the previously published\r\nresults of our experimental investigations characterizing comparative toxicity of the iron oxide Fe3O4 (magnetite) in the form of\r\nmicroparticles and nanoparticles of different size and comparative activity of the defensive alveolar phagocytosis response to their\r\npulmonary deposition. An approach to the substantiation of acceptable workplace exposure limits of metallic nanoparticles is\r\ndiscussed and, specifically, the tentative reference level for magnetite nanoparticles is recommended....
Surface-modified silver nanoparticles (NAg) were encapsulated into a polystyrene (PS) matrix by in situ miniemulsion\r\npolymerization. Silver nanoparticles were modified with 3-aminopropyltrimethoxysilane (APTMS) that acts as a coupling agent\r\nand costabilizer in the polymerization reaction. The PS-Nag nanocomposites synthesized via miniemulsion polymerization were\r\nmade at two different concentrations of the initiator (0.7 and 2.5 g/L in H2O); at higher concentration of the initiator the\r\nconversion and efficiency of encapsulation increases, and the average particle size decreases. The PS-NAg composites showed\r\nexcellent antimicrobial performance toward bacteria such as Escherichia coli and Staphylococcus aureus....
It is important to control the degradation rate of a tissue-engineered scaffold so that the scaffold will degrade in an appropriate\r\nmatching rate as the tissue cells grow in. A set of potential tissue engineering scaffolds with controllable rates of degradation were\r\nfabricated from blends of two biocompatible, biodegradable L-tyrosine-based polyurethanes (PEG1000-HDI-DTH and PCL1250-\r\nHDI-DTH) using the electrospinning process. The scaffolds were characterized by mat morphology, fiber diameter, diameter\r\ndistribution, pore size, and hydrolytic degradation behavior. The majority of the scaffolds, despite having radically different\r\nchemical compositions, possessed no statistical difference with pore sizes and fiber diameters. The degradation pattern observed\r\nindicated that scaffolds consisting of a greater mass percentage of PEG1000-HDI-DTH decayed to a greater extent than those\r\ncontaining higher concentrations of PCL1250-HDI-DTH. The degradation rates of the electrospun scaffolds were much higher than\r\nthose of the thin cast films with same compositions. These patterns were consistent through all blends. The work demonstrates one\r\npractical method of controlling the degradation of biopolymer scaffolds without significantly affecting an intended morphology....
Liquid phase morphology control of ZnO crystals was realized with simple aqueous solution system. ZnO nanowires were successfully\r\nfabricated at 50?C. They were over 50 �µm in length and about 100nm in width. Aspect ratio was estimated to be over\r\n500. They had no branches and were obtained without aggregations. Curved nano-wires clearly indicated high flexibility and high\r\nmechanical strength. Additionally, ellipse particles, hexagonal rods and particles were fabricated in the solutions. Morphology,\r\ncrystal growth speed, and preferred growth faces were well-controlled by precise adjustment of growth conditions....
Research on mixed matrix membranes in which nanoparticles are used to enhance the membrane�s performance in terms of flux,\r\nseparation, and fouling resistance has boomed in the last years. This review probes on the specific features and benefits of one\r\nspecific type of nanoparticles with a well-defined cylindrical structure, known as nanotubes. Nanotube structures for potential use\r\nin membranes are reviewed. These comprise mainly single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes\r\n(MWCNTs), but also other structures and materials, which are less studied for membrane applications, can be used. Important\r\nissues related to polymer-nanotube interactions such as dispersion and alignment are outlined, and a categorization is made of the\r\nresultant membranes. Applications are reviewed in four different areas, that is, gas separation, water filtration, drug delivery, and\r\nfuel cells....
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