Temperature-and pH-Sensitive Nanohydrogels of Poly(N-Isopropylacrylamide) for Food Packaging Applications: Modelling the Swelling-Collapse Behaviour

Temperature-sensitive poly(N-isopropylacrylamide) (PNIPA) nanohydrogels were synthesized by nanoemulsion polymerization in water-in-oil systems. Several cross-linking degrees and the incorporation of acrylic acid as comonomer at different concentrations were tested to produce nanohydrogels with a wide range of properties. The physicochemical properties of PNIPA nanohydrogels, and their relationship with the swelling-collapse behaviour, were studied to evaluate the suitability of PNIPA nanoparticles as smart delivery systems (for active packaging). The swelling-collapse transition was analyzed by the change in the optical properties of PNIPA nanohydrogels using ultraviolet-visible spectroscopy. The thermodynamic parameters associated with the nanohydrogels collapse were calculated using a mathematical approach based on the van't Hoff analysis, assuming a two-state equilibrium (swollen to collapsed). A mathematical model is proposed to predict both the thermally induced collapse, and the collapse induced by the simultaneous action of two factors (temperature and pH, or temperature and organic solvent concentration). Finally, van't Hoff analysis was compared with differential scanning calorimetry. The results obtained allow us to solve the problem of determining the molecular weight of the structural repeating unit in cross-linked NIPA polymers, which, as we show, can be estimated from the ratio of the molar heat capacity (obtained from the van't Hoff analysis) to the specific heat capacity (obtained from calorimetric measurements).

Fiabilidad de diferentes pruebas que se utilizan para evaluar el riesgo de lesión del miembro inferior en mujeres deportistas

233 p. : il. + anexo (247 p.)

Plan de Cuidados Estandarizado en Pacientes con Amputación Traumática de Miembro Inferior

La amputación traumática de miembro inferior constituye un proceso complicado de adaptación y superación en el que se producen repercusiones en la persona tanto a nivel físico como psicológico y social. Este tipo de cirugía supone un cambio drástico en la vida de quienes las padecen y sus familias, siendo a menudo adultos jóvenes. En consecuencia, todo el equipo multidisciplinar, pero la enfermera de atención domiciliaria especialmente, juega un papel decisivo a la hora de realizar un seguimiento, estabilizar emocionalmente al paciente e integrarle con el entorno, alcanzando el mayor nivel posible de independencia y autonomía (Modelo de Virginia Henderson). Ésta, garantiza la continuidad de cuidados mediante la supervisión, realización de intervenciones y apoyo a la persona y a la familia, tarea que quizás queda relegada por la actuación inicial de la enfermera hospitalaria. Con el objetivo de brindar unos cuidados integrales y de calidad en el domicilio, se elabora un Plan de Cuidados Estandarizado (PCE) específico para este grupo de pacientes. Se utiliza el Lenguaje Enfermero Estandarizado (LEE) a través de las taxonomías NANDA-NOC-NIC, tal y como se recoge en el Real Decreto 1093/2010 del Boletín Oficial del Estado y se adapta en el 2012 al Boletín Oficial del País Vasco.

¿Actividad cotidiana o práctica ritual? Agrupación de 14 colgantes líticos del Magdaleniense Inferior en la cueva de Praileaitz 1 (Deba, Gipuzkoa)

Homenaje a Ignacio Barandiarán Maestu / coord. por Javier Fernández Eraso, Juan Santos Yanguas

Temperature-and pH-Sensitive Nanohydrogels of Poly(N-Isopropylacrylamide) for Food Packaging Applications: Modelling the Swelling-Collapse Behaviour

Temperature-sensitive poly(N-isopropylacrylamide) (PNIPA) nanohydrogels were synthesized by nanoemulsion polymerization in water-in-oil systems. Several cross-linking degrees and the incorporation of acrylic acid as comonomer at different concentrations were tested to produce nanohydrogels with a wide range of properties. The physicochemical properties of PNIPA nanohydrogels, and their relationship with the swelling-collapse behaviour, were studied to evaluate the suitability of PNIPA nanoparticles as smart delivery systems (for active packaging). The swelling-collapse transition was analyzed by the change in the optical properties of PNIPA nanohydrogels using ultraviolet-visible spectroscopy. The thermodynamic parameters associated with the nanohydrogels collapse were calculated using a mathematical approach based on the van't Hoff analysis, assuming a two-state equilibrium (swollen to collapsed). A mathematical model is proposed to predict both the thermally induced collapse, and the collapse induced by the simultaneous action of two factors (temperature and pH, or temperature and organic solvent concentration). Finally, van't Hoff analysis was compared with differential scanning calorimetry. The results obtained allow us to solve the problem of determining the molecular weight of the structural repeating unit in cross-linked NIPA polymers, which, as we show, can be estimated from the ratio of the molar heat capacity (obtained from the van't Hoff analysis) to the specific heat capacity (obtained from calorimetric measurements).