Building maps of local apparent conductivity of the epicardium with a 2-D electrophysiological model of the heart

In this paper, we address the problem of estimating the parameters of an electrophysiological model of the heart from a set of electrical recordings. The chosen model is the reaction-diffusion model on the transmembrane potential proposed by Aliev and Panfilov. For this model of the transmembrane, we estimate a local apparent two-dimensional conductivity from a measured depolarization time distribution. First, we perform an initial adjustment including the choice of initial conditions and of a set of global parameters. We then propose a local estimation by minimizing the quadratic error between the depolarization time computed by the model and the measures. As a first step we address the problem on the epicardial surface in the case of an isotropic version of the Aliev and Panfilov model. The minimization is performed using Brent method without computing the derivative of the error. The feasibility of the approach is demonstrated on synthetic electrophysiological measurements. A proof of concept is obtained on real electrophysiological measures of normal and infarcted canine hearts.     

Ocular Effects of Exposure to 40, 75, and 95 GHz Millimeter Waves

The objective of this study was to develop a model of ocular damage induced by 40, 75, and 95 GHz continuous millimeter waves (MMW), thereby allowing assessment of the clinical course of ocular damage resulting from exposure to thermal damage-inducing MMW. This study also examined the dependence of ocular damage on incident power density. Pigmented rabbit eyes were exposed to 40, 75, and 95 GHz MMW from a spot-focus-type lens antenna. Slight ocular damage was observed 10 min after MMW exposure, including reduced cornea thickness and reduced transparency. Diffuse fluorescein staining around the pupillary area indicated corneal epithelial injury. Slit-lamp examination 1 day after MMW exposure revealed a round area of opacity, accompanied by fluorescence staining, in the central pupillary zone. Corneal edema, indicative of corneal stromal damage, peaked 1 day after MMW exposure, with thickness gradually subsiding to normal. Three days after exposure, ocular conditions had almost normalized, though corneal thickness was slightly greater than that before exposure. The 50% probability of ocular damage (DD₅₀) was in the order 40?>?95?≈?75 GHz at the same incident power densities.     

A Real-coded Genetic Algorithm Applied to Optimum Design of a Low Solidity Vaned Diffuser for Diffuser Pinup

InboductionThe requirements for high efficiency and high headhave led to a widesPread use of vaned diffuser in diffeserPumP. Usually the kinetic eneny of the flow leaving theimPeller of a diffeser PUm stage is equlvalent toWtimately 20% to 40% of the total work inPu underthe tyPical operatin conditions. If an efficient diffoserpumP is to be designed, much Of thes kinehc eneTgy mustbe recovered efficienhy The vaned thser can convertboetic energy into a static pressure rise. HoweVer thecon…     

Influence of side chain length on fluorescence intensity of ROMP-based polymeric nanoparticles and their tumor specificity in in-vivo tumor imaging

In this study, amphiphilic brush-like copolymers conjugated with short alkyl or long polymeric chains of various lengths are synthesized using ring-opening metathesis polymerization (ROMP) of substituted norbornadiene monomers followed by chemical transformations. These amphiphilic copolymers form spherical self-assemblies in aqueous media with diameters of 132-244 nm. The low critical aggregation concentration of these assemblies (2.5 × 10(-3) -1.4 × 10(-5) g/L) indicates that they are quite stable in dilute conditions. An appropriate length of polymer side chain that conjugates the polymer backbone with a hydrophobic ICG (indocyanine green) moiety enhanced the fluorescence intensities of these self-assemblies in aqueous solution as well as in tumor-bearing mice. A longer side chain conjugated with tumor targeting agents could significantly affect the tumor specificity of self-assemblies to a greater extent. The self-assemblies bearing hydrophilic tumor targeting agents, such as a glucosamine molecule and a cyclic RGD (arginine-glycine-asparatic acid) peptide, accumulated in tumor tissues with high selectivity, while those having a hydrophobic targeting agent, such as folate moieties, accumulated in tumor sites with low selectivity. The results demonstrated here unambiguously indicate that the fluorescence intensity and tumor specificity of self-assemblies are strongly affected by the length of side chains that conjugate with dyes and targeting agents.     

Characterization and fracture behavior of bismuth–tin thermal fuse alloy wires produced by the Ohno continuous casting process

Bismuth–tin binary alloys containing high bismuth concentrations of 40 to 77% were continuously cast into wires of approximately 2 mm in diameter with casting speeds between 15 and 150 mm min^?1 using the Ohno Continuous Casting (OCC) process. The microstructure was examined and tensile tests were performed for wires cast at various speeds. It was found that for slowly cast wires containing large primary bismuth dendrites, bismuth fracture occurring along the (111) plane exerted a key role in wire fracture, while microstructures with refined bismuth dendrites exhibited a mixture of bismuth cracks and inter-phase decohesion, allowing the accommodation of larger strain before wire fracture. For wires with microstructures containing primary tin dendrites, inter-phase decohesion played a key role in wire fracture.     

Control of self organization in conjugated polymer fibers

We propose new strategy to facilitate the fabrication of conjugated polymer fiber with higher oriented structures, which focused on electrospinning of a blend solution of regioregular poly(3-hexylthiophene) (rr-P3HT) and poly(vinyl pyrrolidone) (PVP). SEM observation revealed that the blend system forms homogeneous composite nanofibers. This system exhibits the specific feature of strong interchain contribution of P3HT from UV-vis absorption, fluorescence spectroscopic, XRD, and photoelectron spectrometric (for HOMO levels) investigations. We also demonstrate the removal of the PVP component from the P3HT/PVP composite fibers through the selective extraction and such strong interchain stacking of pristine P3HT fiber mat can be remarkably maintained.     

Biomimetic assembly of proteins into microcapsules on oil-in-water droplets with structural reinforcement via biomolecular-recognition-based cross-linking of surface peptides

By mimicking the stabilization of bacterial membranes with S-layer proteins, a novel process to fabricate highly stable protein microcapsules is introduced. In this strategy, engineered collagen peptides with site-specific biotinylation are assembled into microcapsules on the oil-in-water droplets, and the resulting microcapsules are reinforced by biomolecular-recognition-based cross-linking with the protein. Furthermore the microcapsules are shown to be versatile scaffolds for developing functionalized hierarchical colloidosomes for important biotechnological applications.     

Enhancement of thermostability of kojibiose phosphorylase from Thermoanaerobacter brockii ATCC35047 by random mutagenesis

Random mutation by error-prone PCR was introduced into kojibiose phosphorylase from Thermoanaerobacter brockii ATCC35047. One thermostable mutant enzyme, D513N, was isolated. The D513N mutant enzyme showed an optimum temperature of 67.5-70 degrees C (the wild type, 65 degrees C), and thermostability up to 67.5 degrees C (the wild type, up to 60 degrees C). The half-lives of D513N were estimated to be 135 h at 60 degrees C, 110 min at 70 degrees C and 6 min at 75 degrees C, respectively. They were about 1.6-fold, 7-fold and 6-fold longer than those of the wild-type enzyme, respectively.     

Reconstruction of cartilage tissue using scaffold-free organoid culture technique

We applied the scaffold-free culture method to chondrocytes and attempted to reconstitute articular cartilage grafts. Primary rat costal chondrocytes were immobilized into hollow fibers by centrifugation at a density of 3 x 10(8) cells/cm(3) to induce the formation of cylindrical-shaped multicellular aggregates (organoids) and cultured for one month. The organoids were evaluated by histological and gene expression analyses. Chondrocytes formed cylindrical organoids in hollow fibers (HFs). Histochemical analysis revealed the accumulation of a cartilage extracellular matrix (collagen and proteoglycan) around cells in the lumen of HFs with culture time, forming a low-cellular-density tissue similar to native cartilage by day 28. Furthermore, in contrast to that in traditional monolayer culture, the organoid maintained the gene expression of the cartilage extracellular matrix (type II collagen, aggrecan) for one month of culture. In conclusion, our organoid formation method was effective in producing a cartilage-like tissue. This result suggests that the technique may be applicable to the development of an articular cartilage graft.     

Utilization of adzuki bean extract as a natural antioxidant in cured and uncured cooked pork sausages

A commercial adzuki bean extract (AE) was evaluated for antioxidant effectiveness in cured and uncured cooked pork sausages. TBARS values, instrumental color evaluation and sensory panel scores were assessed. For uncured sausages, AE at 0.2% was equally effective as 0.1% butylated hydroxytoluene (BHT) in reducing TBARS values. Similarly, AE at 0.2% significantly (P<0.01) reduced the TBARS in cured sausages. Incorporation of 0.2% AE into sausages produced higher (P<0.05) CIE lab color a* value and lower (P<0.05) L* and b* values. Sensory panels did not detect any difference in color, odor, taste, flavor, and overall acceptance in uncured pork sausages with addition of 0.2% AE. However, there were adverse changes in the color and odor of cured sausages, even though the taste, flavor, and overall acceptance were similar. Therefore, the results suggest that AE is a potential antioxidant.