Time filter

Source Type

Zamudio, Spain

Garcia-Huete N.,Basque Center for Materials | Laza J.M.,University of the Basque Country | Cuevas J.M.,Gaiker Technology Center | Vilas J.L.,Basque Center for Materials | And 2 more authors.
Radiation Physics and Chemistry | Year: 2014

A gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical, chemical and mechanical properties. Gamma irradiation originates free radicals able to induce chain scission or recombination of radicals, which induces annihilation, branching or crosslinking processes. The aim of this work is to research the structural, thermal and mechanical changes induced on a commercial polycyclooctene (PCO) when it is irradiated with a gamma source of 60Co at different doses (25-200kGy). After gamma irradiation, gel content was determined by Soxhlet extraction in cyclohexane. Furthermore, thermal properties were evaluated before and after Soxhlet extraction by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as mechanical properties were measured by Dynamic Mechanical Thermal Analysis (DMTA). The results showed the variations of the properties depending on the irradiation dose. Finally, a first approach to evaluate qualitatively the shape memory behaviour of all irradiated PCO samples was performed by a visually monitoring shape recovery process. © 2014 Elsevier Ltd. Source

Arnandis-Chover T.,Polytechnic University of Valencia | Morais S.,Polytechnic University of Valencia | Tortajada-Genaro L.A.,Polytechnic University of Valencia | Puchades R.,Polytechnic University of Valencia | And 3 more authors.
Talanta | Year: 2012

A DNA oligonucleotide array for duplex pathogen detection on a DVD platform is developed. The assay involves hybridization of PCR products and optical detection using compact disc technology. Different DNA array constructions for attachment of synthetic oligonucleotides on to DVD surface are evaluated, finding that streptavidin-biotin coupling method yielded the highest sensitivity in combination with enzymatic signal amplification. Issues of importance for the DNA array construction such immobilized probes design, PCR product labeling strategy and composition of the hybridization buffer were addressed. The methodology was proved scoring single nucleotide polymorphisms with high selectivity. The assay capability was also demonstrated by the identification of two pathogenic microorganisms in powder milk samples. In fifty minutes, the DVD-array system identifies Salmonella spp. and Cronobacter spp. (previously named Enterobacter sakazakii) precise and simultaneously with a sensitivity of 100 and 102 cfu/mL, respectively, in infant milk. Results were in good agreement with those obtained by quantitative real-time PCR. © 2012 Elsevier B.V. All rights reserved. Source

Cuevas J.M.,Gaiker Technology Center | Rubio R.,Gaiker Technology Center | Laza J.M.,University of the Basque Country | Vilas J.L.,University of the Basque Country | And 2 more authors.
Smart Materials and Structures | Year: 2012

The mechanical response of a series of semicrystalline shape memory polymers was considerably enhanced by incorporating short glass fibres without modifying the thermo-responsive actuation based on balanced crystallinity and elasticity. The effect of different fractions of inorganic reinforcement on thermo-mechanical properties was evaluated using different instrument techniques such as differential scanning calorimetry (DSC), thermogravimetry (TGA), dynamic mechanical thermal analysis (DMTA) and three-point flexural tests. Moreover, we studied the inorganic reinforcement influence on the shape memory actuation capabilities by thermo-mechanical bending cycle experiments. As demonstrated, the manufactured polymer composites showed excellent shape memory capacities, similar to neat active polymer matrices, but with outstanding improvements in static and recovering mechanical performance. © 2012 IOP Publishing Ltd. Source

Garcia-Huete N.,Basque Center for Materials | Laza J.M.,University of the Basque Country | Cuevas J.M.,Gaiker Technology Center | Gonzalo B.,Gaiker Technology Center | And 2 more authors.
Journal of Polymer Research | Year: 2014

Self-repair properties based on shape-memory features of covalently crosslinked semi-crystal line polyalkenamers were demonstrated by thermal-activated recovery of performed surface marks (indented holes and scratches). Shape memory polymers were prepared by mixing a commercial polycyclooctene (PCO) with different percentages of peroxide, and then these mixtures were processed by compression moulding to obtain crosslinked sheets. With the aid of a hardness test pencil, holes and scratches in the surface of the materials were realized with different known forces (5, 10 and 15 N). The disappearance of surface defects was evaluated using both optical and contact surface profilometry, as well as optical microscopy under heating processes. This technique allowed evaluating shape recovery ratios of edgewise holes in PCO samples. In parallel, the analysis of maximum depth of indentations with temperature for edgewise samples by optical microscopy allows evaluating shape recovery. As a complementary tool for analysing thermal shaperecovery and surface resistance to indentation, thermal properties and hardness were investigated by DSC and Shore durometer test, respectively. © Springer Science+Business Media Dordrecht 2014. Source

Lucero M.L.,FAES FARMA S.A. | Gonzalo A.,FAES FARMA S.A. | Mumford R.,Charles River Laboratories | Betanzos M.,Gaiker Technology Center | Alejandro A.,Gaiker Technology Center
Drug and Chemical Toxicology | Year: 2012

Knowledge of the biotransformation of oral H1 antihistamines is clinically important because it can define their pharmacokinetic profile through possible effects on absorption (i.e., first-pass metabolism) and elimination. Further, clinically significant interactions with inhibitors of cytochrome P450 (CYP) have previously been reported for drugs of this therapeutic group, such as terfenadine and astemizole, indicating the possibility of drug-drug interactions involving agents that share the same metabolic pathway. The aim of this article was to review the preclinical testing of a new antihistamine (i.e., bilastine) in terms of its biotransformation in various animal species, including humans, and to evaluate its potential for possible drug-drug interactions involving the CYP system. A wide array of preclinical experiments were reviewed, all of which demonstrated that bilastine undergoes minimal metabolism in all species tested to date, including humans. Further, bilastine did not interact significantly, either as an inhibitor or inducer, with the CYP enzyme system, suggesting a low propensity for involvement in drug-drug interactions. These characteristics demonstrate the potential for bilastine to be a good choice for allergic patients receiving treatment for other concomitant diseases, including those with renal or hepatic dysfunction. © 2012 Informa Healthcare USA, Inc. Source

Discover hidden collaborations