Effects of fibronectin and laminin on structural, mechanical and transport properties of 3D collageneous network

Recent studies, on cells cultured in 3D collagen gels, have shown that, beside from their well known biochemical role, fibronectin (FN) and laminin (LM) affect cell functions via a modification of mechanical and structural properties of matrix due to interaction with collagen molecules. Though biochemical properties of FN and LM have been widely studied, little is known about their role in collagen matrix assembly. The aim of this work was to characterize FN- and LM-based collagen semi-interpenetrating polymer networks (semi-IPNs), in order to understand how these biomacromolecular species can affect collagen network assembly and properties. Morphology, viscoelasticity and diffusivity of collagen gels and FN- and LM-based collagen semi-IPNs were analysed by Confocal Laser Scanning microscopy (CLSM), Environmental Scanning Electron microscopy (ESEM), Transmission Electron microscopy (TEM), Rheometry and Fluorescence Recovery After Photobleaching (FRAP) techniques. It was found that FN and LM were organized in aggregates, interspersed in collagen gel, and in thin fibrils, distributed along collagen fibres. In addition, high FN and LM concentrations affected collagen fibre assembly and structure and induced drastic effects on rheological and transport properties.     

Drawing trees in a streaming model

We pose a new visualization challenge, asking Graph Drawing algorithms to cope with the requirements of Streaming applications. In this model a source produces a graph one edge at a time. When an edge is produced, it is immediately drawn and its placement cannot be altered. The drawing has an image persistence, that controls the lifetime of edges. If the persistence is k, an edge remains in the drawing for the time spent by the source to generate k edges, and then it fades away. In this model we study the area requirement of planar straight-line grid drawings of trees and we assess the output quality of the presented algorithms by computing the competitive ratio with respect to the best known offline algorithms.     

Available Lysine Content during Cereal Flake Production

The available lysine contents during industrial production of wheat, rye, barley and oat flakes have been investigated. Obtained results show that hydrothermal treatment (120°C, 60 min, 1·99×10⁵ Pa) of whole cereal grain as well as flaking process (70°C, gap 0·3 mm) did not significantly affect lysine availability. When summary effects in particular processing phases, including thermal treatment (100°C) of oat grains—before fragmentation and hydrothermic treatment—is calculated, the loss of available lysine was significant during production of rye flakes (4·90%) and oat flakes (8·22%). Protein nutritive quality, expressed as a chemical score based on the available lysine contents in relation to NAS/NRC reference pattern was on the average 47·9%, 46·5%, 41·0% and 38·6% for oat, rye, barley and wheat flakes, respectively. © 1997 SCI     

Low-cost CMOS pulse generator for UWB systems

The design of a CMOS ultra-wideband (UWB) pulse generator for impulse radio system transmission in the 3.1-10.6 GHz frequency band is presented. The pulse generator uses an elementary pulse combiner, which appears to be well suited to tune the synthesised pulse. The generator is designed with no inductors or external filter in order to reduce the die area and the production cost. Simulations with a standard 0.13 mum CMOS design kit show a 600 mV_pp pulse that satisfies the FCC regulation mask and a power consumption of 2.64 mW with a 100 MHz pulse repetition frequency.