The formation of a nanohybrid shish-kebab (NHSK) structure in melt-processed composites of poly (ethylene terephthalate) (PET) and multi-walled carbon nanotubes (MWCNTs)

The combination of synchrotron Small- and Wide-Angle X-ray scattering (SAXS/WAXS), and thermal analysis was used to follow the evolution of crystalline morphology and crystallization kinetics in a series of melt-processed composites of poly(ethylene terephthalate) (PET) and multiwall carbon nanotubes (MWCNT). The as-extruded PET-MWCNT composites underwent both hot and cold isothermal crystallizations where a final oriented nanohybrid shish-kebab (NHSK) crystalline structure was observed. An oriented NHSK structure was seen to persist even after melting and recrystallization of the composites. From the scattering data, we propose a model whereby the oriented MWCNTs act as heterogeneous nucleation surfaces (shish) and the polymer chains wrap around them and the crystallites (kebabs) grow epitaxially outwards during crystallization. However, depending on crystallization temperature, unoriented crystallites also grow in the polymer matrix, resulting in a combination of a NHSK and lamellar morphology. In contrast, the neat PET homopolymer showed the sporadic nucleation of a classic unoriented lamellar structure under the same isothermal crystallization conditions. These results provide a valuable insight into the distinctive modification of the crystalline morphology of melt-processed polymer-MWCNT composites prior to any secondary processing, having a significant impact on the use of MWCNTs as fillers in the processing and modification of the physical and mechanical properties of engineering polymers

Aportaciones del terapeuta ocupacional usando la terapia de integración sensorial en servicios de atención temprana y postemprana

Cada vez es mayor la presencia de terapeutas ocupacionales en España que trabajan en el ámbito de la pediatría, en particular en los servicios de atención temprana y postemprana. Los niños y sus familias encuentran en el profesional de terapia ocupacional una persona capaz de aumentar y mejorar su participación y desempeño en las actividades que llevan a cabo en sus diferentes entornos. Son muchos los marcos de referencia usados en terapia ocupacional pediátrica, el uso de ellos dependerá de la formación del propio terapeuta y de las necesidades de los niños y familias con los que intervenga. Se pretende establecer una relación entre el marco de referencia de integración sensorial y el trabajo en estos servicios de atención temprana y postemprana, con la finalidad de entender un poco más la trascendencia de este tipo de intervención de carácter tan lúdico en estas edades

Hacia una pedagogia afectiva del movimiento

Entender la pedagogía desde el concepto de afecto permite adentrarnos a las transformaciones que los cuerpos viven dentro de eventos de aprendizaje. En concreto, este artículo indaga sobre cómo los afectos circulan en situaciones pedagógicas de movimiento localizadas, en 3 sesiones de psicomotricidad, para ir hacia una pedagogía afectiva que explora las transiciones de los cuerpos como manera de repensar las formas de hacer en educación. La metodología usada en este artículo es de una Investigación Basada en las Artes desde una perspectiva de los Nuevos Materialismos. Cómo método, se explora el proceso de elaboración de las cartografías de investigación y cart(e)ografías que aterrizan el movimiento y los afectos de un momento en concreto. Este artículo entiende como resultados aquellos conocimientos surgidos en el proceso de investigación. En ellos, se puede ver como el movimiento permite circular afectos que pueden ser retenidos en la especificidad de cada cuerpo para transformar y aprender. Acercarse a una pedagogía afectiva del movimiento significa ir hacia métodos experimentales pero localizados. De esta manera se pueden explorar estrategias pedagógicas que invitan a repensar la educación a partir de desdibujar las dualidades y las jerarquías, atender a las relaciones, a los movimientos de los cuerpos que nunca son estables y empezar a entender la necesidad de afectar y ser afectado para poder transformarse y aprender

Beyond the H2/CO2 upper bound: one-step crystallization and separation of nano-sized ZIF-11 by centrifugation and its application in mixed matrix membranes

The synthesis of nano-sized ZIF-11 with an average size of 36 ± 6 nm is reported. This material has been named nano-zeolitic imidazolate framework-11 (nZIF-11). It has the same chemical composition and thermal stability and analogous H2 and CO2 adsorption properties to the conventional microcrystalline ZIF-11 (i.e. 1.9 ± 0.9 μm). nZIF-11 has been obtained following the centrifugation route, typically used for solid separation, as a fast new technique (pioneering for MOFs) for obtaining nanomaterials where the temperature, time and rotation speed can easily be controlled. Compared to the traditional synthesis consisting of stirring + separation, the reaction time was lowered from several hours to a few minutes when using this centrifugation synthesis technique. Employing the same reaction time (2, 5 or 10 min), micro-sized ZIF-11 was obtained using the traditional synthesis while nano-scale ZIF-11 was achieved only by using centrifugation synthesis. The small particle size obtained for nZIF-11 allowed the use of the wet MOF sample as a colloidal suspension stable in chloroform. This helped to prepare mixed matrix membranes (MMMs) by direct addition of the membrane polymer (polyimide Matrimid®) to the colloidal suspension, avoiding particle agglomeration resulting from drying. The MMMs were tested for H2/CO2 separation, improving the pure polymer membrane performance, with permeation values of 95.9 Barrer of H2 and a H2/CO2 separation selectivity of 4.4 at 35 °C. When measured at 200 °C, these values increased to 535 Barrer and 9.1.Financial support from the Spanish MINECO (MAT2013-40566-R, CTQ2012-31762, and RyC-2009-03913), the Aragón Government and the ESF is gratefully acknowledged. In addition, research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 608490, project M4CO2. Finally, the use of the Servicio General de Apoyo a la Investigación-SAI (Universidad de Zaragoza) is acknowledged

Melt processing and properties of linear low density polyethylene-graphene nanoplatelet composites

Composites of Linear Low Density Polyethylene (LLDPE) and Graphene Nanoplatelets (GNPs) were processed using a twin screw extruder under different extrusion conditions. The effects of screw speed, feeder speed and GNP content on the electrical, thermal and mechanical properties of composites were investigated. The inclusion of GNPs in the matrix improved the thermal stability and conductivity by 2.7% and 43%, respectively. The electrical conductivity improved from 10-11 to 10-5 S/m at 150 rpm due to the high thermal stability of the GNPs and the formation of phonon and charge carrier networks in the polymer matrix. Higher extruder speeds result in a better distribution of the GNPs in the matrix and a significant increase in thermal stability and thermal conductivity. However, this effect is not significant for the electrical conductivity and tensile strength. The addition of GNPs increased the viscosity of the polymer, which will lead to higher processing power requirements. Increasing the extruder speed led to a reduction in viscosity, which is due to thermal degradation and/or chain scission. Thus, while high speeds result in better dispersions, the speed needs to be optimized to prevent detrimental impacts on the properties.</p

Development of exfoliated layered stannosilicate for hydrogen adsorption

The use of hydrogen as an energy vector leads to the development of materials with high hydrogen adsorption capacity. In this work, a new layered stannosilicate, UZAR-S3, is synthesized and delaminated, producing UZAR-S4. UZAR-S3, with the empirical formula Na4SnSi5O14·3.5H2O and lamellar morphology, is a layered stannosilicate built from SnO6 and SiO4 polyhedra. The delamination process used here comprises three stages: protonation with acetic acid, swelling with nonylamine and the delamination itself with an HCl/H2O/ethanol solution. UZAR-S4 is composed of sheets a few nanometers thick with a high aspect ratio and a surface area of 236 m2/g, twenty times higher than that of UZAR-S3. At −196 °C for UZAR-S4, H2 adsorption reached remarkable values of 3.7 and 4.2 wt% for 10 and 40 bar, respectively, the latter value giving a high volumetric H2 storage capacity of 26.2 g of H2/L.Financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) is gratefully acknowledged through projects with grant numbers: MAT2010-15870, CTQ2012-31229 and CTQ2012-31762, as well as from the Fondo Europeo de Desarrollo Regional (FEDER), Regional Government of Aragón (DGA) and the European Social Fund (ESF). A. Berenguer-Murcia and C. Casado-Coterillo thank the MINECO for Ramón y Cajal fellowships (RyC 2009-03913 at the University of Alicante and RYC-2011-08550 at the University of Cantabria)

Mild cognitive impairment and progression to dementia of Alzheimer's disease

The increase in life expectancy in the Brazilian population raises questions about the preparation of the public health system in identifying elderly patients with signs of cognitive impairment. Currently, as a consequence of the long duration of preclinical phase of Alzheimer's disease, efforts of early detection have been emphasized. Clinical dementia presents an important impact on the individual's caregivers, family, society and economy. Identifying individuals who already have some cognitive impairment, despite remaining functional, as well as analyzing associated comorbidities, constitutes an opportunity to analyze possibilities for future interventions. Dementias are clinical conditions that impose a burden on the health system with its high costs, whereas the identification of individuals with cognitive impairment without dementia can aid patients and their families to plan the future and mitigate costs. This narrative revision can provide general practitioners with more information on the subject.Univ Fed Sao Paulo, UNIFESP, Escola Paulista Med, Psychiat Dept, Sao Paulo, SP, BrazilUniv Estadual Paulista, UNESP, Fac Med Botucatu, Dept Internal Med,Geriatr, Botucatu, SP, BrazilFMB Unesp, Botucatu, SP, BrazilUniv Sao Paulo, Sao Paulo, BrazilHosp Santa Marcelina, Neurol Residency Program, Sao Paulo, BrazilUniv Sao Paulo, Grp Neurol Cognitiva & Comportamento, Sao Paulo, SP, Brazil|Univ Sao Paulo, Ctr Referencia Disturbios Cognit Ceredic, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, UNIFESP, Escola Paulista Med, Psychiat Dept, Sao Paulo, SP, BrazilWeb of Scienc

Andalusian program for early detection of diabetic retinopathy: implementation and 15-year follow-up of a population-based screening program in Andalusia, Southern Spain

Introduction Diabetic retinopathy (DR) is a preventable cause of vision loss and blindness worldwide. We aim at analyzing the impact of a population-based screening program of DR using retinal photography with remote reading in terms of population coverage, diagnosis of asymptomatic DR and impact on visual disability, in the region of Andalusia, Spain, in the period 2005-2019. Research design and methods Descriptive study. Sociodemographic and clinical features included in the Andalusian program for early detection of diabetic retinopathy (APDR) were analyzed. Population coverage, annual incidence of DR, and DR severity gradation were analyzed. Estimated data on prevalence and incidence of legal blindness due to DR were included. Results 407 762 patients with at least one successful DR examination during the study period were included. Most of the performed retinographies (784 584, 84.3%) were 'non-pathological.' Asymptomatic DR was detected in 52 748 (5.9%) retinographies, most of them (94.2%) being classified as 'mild to moderate non-proliferative DR.' DR was detected in 44 815 patients, while sight-threatening DR (STDR) in 6256 patients; cumulative incidence of DR was 11.0% and STDR was 1.5%, as DR and STDR was detected in 44 815 and 6256 patients, respectively. Annual incidence risk per patient recruitment year progressively decreased from 22.0% by January 2005 to 3.2% by June 2019. Conclusions Implementation of a long-term population-based screening program for early detection of DR is technically feasible and clinically viable. Thus, after 15 years of existence, the program has enabled the screening of the vast majority of the target population allowing the optimization of healthcare resources and the identification of asymptomatic DR

Mujer e investigación en el CSIC de Aragón

2011: Año de la mujer investigadora.Peer Reviewe

Mujer e investigación

2 pdfs. de los paneles correspondientes a la Exposición "Mujer e investigación", organizada en 2011 por la Delegación del CSIC en Aragón