Specific interactions in ternary system quaternized polysulfone/mixed solvent

Theoretical and experimental aspects on the specific interactions developed via electrostatic interactions and hydrogen‐bonding in a ternary system formed of a proton‐donor solvent (N,N‐dimethylformamide or methanol), a proton‐acceptor solvent (water), and a quaternized polysulfone with various contents of ionic chlorine, which indicates a proton‐acceptor character, are investigated. Thus, the interactions of the ternary systems are corrected on the basis of the association phenomena defined through association constants. Numerical values for these constants were evaluated as a function of the system composition, by mathematical simulations for an accurate adjustment of preferential adsorption, determined by the Flory–Huggins–Pouchly theoretical approach applied to the experimental data. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers     

Surface and interface properties of functionalized polysulfones: Cell‐material interaction and antimicrobial activity

Quaternized polysulfones with different ionic chlorine content tested for biomedical applications were obtained by quaternization reaction of chloromethylated polysulfones with N,N‐dimethylethanolamine. The relationship between the different physical and chemical characteristics of these polymers and their biocompatible and antimicrobial properties was established for maximizing the selectivity and performance of these materials for biomedical applications. Therefore, topographic reorganization of the polysulfonic films induced by the type of nonsolvent in casting solutions of polymer significantly influences films morphology, depending on the charge density of polyelectrolytes, the hydrophilic/hydrophobic characteristics, as well as on the history of the formed films. Furthermore, the study of the adhesion of red blood cells and cohesion of platelets on the surface of quaternized polysulfone films, as well as analysis of antibacterial activity, using Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 microorganisms, contribute to extending the possible applications of quaternized polysulfones as semipermeable membranes in biomedical domains. POLYM. ENG. SCI., 55:2184–2194, 2015. © 2015 Society of Plastics Engineers     

Impact of Some Properties of Quaternized Polysulfone/Poly(Vinylidene Fluoride) Blend on the Potential Biomedical Applications

Blends of quaternized polysulfones with triphenylphosphonium pendant groups/poly(vinylidene fluoride) were analyzed to establish their impact on the rheological, morphological and surface properties, as well as their interactions with some blood compounds. The rheological functions reflect the influence of both polymers’ chemical structures. Blend compositions of the corresponding films influence the surface tension parameters, increase blend hydrophobicity and, implicitly, decrease the polar surface tension parameters. The specific surface characteristics of polymer blends are related to their interactions with some blood constituents and plasma proteins. Also, the specific microarchitecture of the blend represents an excellent scaffold for medical applications.     

Tracing enteric viruses in the European berry fruit supply chain

In recent years, numerous foodborne outbreaks due to consumption of berry fruit contaminated by human enteric viruses have been reported. This European multinational study investigated possible contamination routes by monitoring the entire food chain for a panel of human and animal enteric viruses.     

Removal of Nitrate from Aqueous Solutions by Electrodialysis

In this work the removal of the nitrate from water was carried out by electrodialysis. In the experiments the effect of the applied voltage, pH value, initial nitrate concentration and duration of treatment on the removal rate of nitrate have been investigated. The results obtained from experiments have indicated that nitrate can be removed effectively applying electrodialysis.     

Spectral characterization and classification of Carpentier-Edwardsheart valves implanted in the aortic position

This paper demonstrates an improvement in the performance of spectral phonocardiography, combined with pattern recognition techniques for monitoring the condition of bioprosthetic heart valves. The analysis of the heart sounds is performed using a modified forward-backward overdetermined Prony's method. Results show that the condition of the bioprosthesis affects mostly the higher part of the spectrum (i.e., above 250 Hz) where no frequency components were found for malfunctioning cases. Therefore, the amplitudes of the three highest frequency components are used as the input vector of an adaptive single layer perceptron-based classifier to identify normal and malfunctioning classes. For the sample set examined, this method gives 100% correct discrimination between normal and malfunctioning Carpentier-Edwards (C-E) valves     

Synthesis and characterization of collagen/hydroxyapatite: magnetite composite material for bone cancer treatment

Our purpose was obtaining and characterizing a complex composite system with multifunctional role: bone graft material and hyperthermia generator necessary for bone cancer therapy. The designed system was a magnetite enriched collagen/hydroxyapatite composite material, obtained by a co-precipitation method. Due to the applied electromagnetic field the magnetite will induce hyperthermia and cause tumoral cell apoptosis. The complex bone graft system was characterised by XRD, FTIR and SEM, while the hyperthermia was quantify by measuring the temperature increase due to the applied alternative electromagnetical field.     

Strategies for combining decision procedures

Implementing efficient algorithms for combining decision procedures has been a challenge and their correctness precarious. In this paper we describe an inference system that has the classical Nelson–Oppen procedure at its core and includes several optimizations: variable abstraction with sharing, canonization of terms at the theory level, and Shostak's streamlined generation of new equalities for theories with solvers. The transitions of our system are fine-grained enough to model most of the mechanisms currently used in designing combination procedures. In particular, with a simple language of regular expressions we are able to describe several combination algorithms as strategies for our inference system, from the basic Nelson–Oppen to the very highly optimized one recently given by Shankar and Rueß. Presenting the basic system at a high level of generality and non-determinism allows transparent correctness proofs that can be extended in a modular fashion when new features are introduced in the system.     

Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents

Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th(4+)/g composite, and 408.62 mg UO(2)(2+)/g composite. The overall adsorption tendency of CS/CPL composite toward UO(2)(2+) and Th(4+) radiocations in the presence of Cu(2+), Fe(2+) and Al(3+), under competitive conditions, followed the order: Cu(2+)>UO(2)(2+)>Fe(2+)>Al(3+), and Cu(2+)>Th(4+)>Fe(2+)>Al(3+), respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO(2)(2+) from the composite CS/CPL, by using 0.1M Na(2)CO(3), was around 92%, and that of Th(4+) ions, performed by 0.1M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively.