Síntesis hidrotermal de nanoparticulas de circona dopada con itria e itria/escandia y su procesamiento en película delgada por EPD

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias ; Instituto de Cerámica y Vidrio (CSIC). Fecha de lectura: 28-06-201

Contrast sensitivity evaluation with filter contact lenses in patients with retinitis pigmentosa: a pilot study

Purpose: the aim of this pilot study was to test whether retinitis pigmentosa patients would benefit from filter contact lenses as an effective optical aid against glare and photophobia. Methods: fifteen subjects with retinitis pigmentosa were enrolled in this study. All of them were evaluated with filter soft contact lenses (MaxSight), filter glasses (CPF 527) and without filters (control). All patients were assessed for the three aid conditions by means of best corrected visual acuity (BCVA), contrast sensitivity (without glare and with central and peripheral glare)(CSV-1000) and a specific subjective questionnaire about quality of vision. Results: BCVA was slightly better with filters than without filter but the differences were not statistically significant. Contrast sensitivity without glare improved significantly with the contact lenses (p<0.05). The central glare had significant differences for the frequencies of 3 cpd and 18 cpd between the contact lens filter and the control group (p=0.021 and p=0.044, respectively). For the peripheral glare contrast sensitivity improved with contact lens versus control group for highest frequencies, 12 and 18 cpd (p<0.001 and p=0.045, respectively). According to the questionnaire the contact lens filter gave them more visual comfort than the glasses filter under the scenarios of indoors glare, outdoors activities and indoors comfort. Conclusion: the filter contact lenses seem to be a good option to improve the quality of vision of patients with retinitis pigmentosa

Facile Preparative Access to Bioactive Silicon Oxycarbides with Tunable Porosity

In the present work, Ca-containing silicon oxycarbides (SiCaOC) with varying Ca content have been synthesized via sol-gel processing and thermal treatment in inert gas atmosphere (pyrolysis). It has been shown that the as-prepared SiCaOC materials with low Ca loadings (Ca/Si molar ratios = 0.05 or 0.12) were X-ray amorphous; their glassy network contains Q(3) sites, indicating the presence of Ca2+ at non-bridging-oxygen sites. SiCaOC with high Ca content (i.e., Ca/Si molar ratio = 0.50) exhibits the presence of crystalline calcium silicate (mainly pseudowollastonite). Furthermore, it has been shown that the incorporation of Ca into the SiOC glassy network has a significant effect on its porosity and specific surface area. Thus, the as-prepared Ca-free SiOC material is shown to be non-porous and having a specific surface area (SSA) of 22.5 m(2)/g; whereas SiCaOC with Ca/Si molar ratio of 0.05 exhibits mesoporosity and a SSA value of 123.4 m(2)/g. The further increase of Ca content leads to a decrease of the SSA and the generation of macroporosity in SiCaOC; thus, SiCaOC with Ca/Si molar ratio of 0.12 is macroporous and exhibits a SSA value of 39.5 m(2)/g. Bioactivity assessment in simulated body fluid (SBF) confirms the hydroxyapatite formation on all SiCaOC samples after seven days soaking, unlike the relatively inert ternary silicon oxycarbide reference. In particular, SiCaOC with a Ca/Si molar ratio of 0.05 shows an increased apatite forming ability compared to that of SiCaOC with Ca/Si molar ratio of 0.12; this difference is considered to be a direct consequence of the significantly higher SSA of the sample with the Ca/Si ratio of 0.05. The present work indicates two effects of Ca incorporation into the silicon oxycarbide glassy network on its bioactivity: Firstly, Ca2+ is shown to contribute to the slight depolymerization of the network, which clearly triggers the hydroxyapatite formation (compare the bioactive behavior of SiOC to that of SiCaOC with Ca/Si molar ratio 0.12 upon SBF exposure); secondly, the Ca2+ incorporation seems to strongly affect the porosity and SSA in the prepared SiCaOC materials. There is an optimum of Ca loading into the silicon oxycarbide glassy network (at a Ca/Si molar ration of 0.05), which provides mesoporosity and reaches maximum SSA, both highly beneficial for the bioactive behavior of the materials. An increase of the Ca loading leads, in addition to the crystallization of calcium silicates, to a coarsening of the pores (i.e., macroporosity) and a significant decrease of the SSA, both negatively affecting the bioactivity

Positron annihilation study of defect distribution in 8YSZ nanostructure

The impact of the interfacial contribution on overall properties increases with decreasing grain size of polycrystalline materials. It is well known that distribution and size of cluster defects are rather different in bulk than grain boundaries. In light of "bottom-up" approaches, a study at the atomic level determining the distribution of crystallographic defects could clarify their contribution to the macroscopic properties, and then differentiate materials for outstanding or precise applications. In this work, Positron Annihilation Spectroscopy (PAS) is used to characterize the distribution of defects within 8 mol% Y₂O₃-stabilized zirconia (8YSZ) structures prepared by sintering through three different thermal treatments, i.e. a conventional thermal cycle in air and N₂/H₂ atmosphere, and a fast firing cycle in air, which lead to average grain sizes < 260 nm.The authors would like to acknowledge the financial support from the Spanish Government through the projects MAT2009-14448-C02-01 and IPT-310000-2010-12.Publicad

Responsabilidad social universitaria: Estudio iberoamericano sobre la influencia de la educación en la formación de profesionales responsables en la sociedad

Resumen: El objeto de análisis en esta investigación desarrollada en población universitaria de diferentes países y áreas de estudio se centra en la influencia que tendría la educación superior desde la formación académica, en generar un sentido de responsabilidad social en alumnado. Participan equipos de investigación de universidades españolas , de Chile, Colombia y Perú . Este trabajo presenta un marco teórico que entiende como responsabilidad social de la educación superior la orientación en materia de valores hacia el bien común, que favorece el desarrollo de comportamientos socialmente responsables, así como habilidades empáticas para comprender a las demás personas, consiguiendo así formar a excelentes profesionales comprometidos con la sociedad. Así mismo, ofrece un modelo de metodología colaborativa e innovadora que permita afrontar los retos que supone para la investigación universitaria, la creación de un espacio iberoamericano de conocimiento, enmarcado en la globalización de nuestras sociedades. Constituye una experiencia de trabajo que todavía viene siendo desarrollada y su importancia radica en la descripción del proceso que se está llevando a cabo. Abstract: The study about the influence of higher education on social responsibility is analyzed in this research developed in college students from different countries and areas of study. Research teams are from universities of Spain, Chile, Colombia and Peru . In this paper it is proposed a theoretical framework, understanding social responsibility of higher education focused on the academic teaching of values for the common good, promoting the development of socially responsible behavior and providing empathic abilities to understand other people, thus forming excellent professionals committed to society. Also, we encourage the promotion of innovative methods of research in order to meet the challenges proposed under the formulation of an Iberoamerican context of knowledge. The present paper is the first part of a research on development, with the intention of offer a perspective about the theory and methodology used

Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers. Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers. Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (). However, no significant differences were found () for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery () but no statistical differences were found in SCT (). Correlations between pre- and postsurgery were found for all tonometers used, with and for the air pulse tonometer, and for Perkins, and and for Diaton. Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment

Preliminary Studies of the Toxicity of Agaricus Bisporous Aqueous Enzymatic Extracts (AbAEE) In Rats

The health benefits of extracts from Agaricus bisporus greatly extend its use as components of new functional foods for the treatment and prevention of diseases, rather than restricting it to a good food with high nutritional value and good flavor. A. bisporus aqueous enzymatic extracts (AbAEE) have unique flavor, good taste, and health benefits which makes it a good candidate for its incorporation in different matrices for development of new functional foods and nutraceuticals. The potential use of AbAEE as nutraceutical or incorporated as a part of new functional foods requires its characterization and a subsequent food safety study. The focus of this paper was to carry out a preliminary toxicological study on experimental animals (rats in this case) by acute and sub-chronic oral administration. To evaluate potential adverse effects of AbAEE at high doses the acute toxic class method was used. After administration of the preset doses, behavior changes, toxic symptoms, and deaths were observed continuously for 1 h after treatment and then intermittently at 4th, 8th and 24th h. After these initial observations, the rats were further observed for up to 14 consecutive days for any signs of toxicity and/or death. Because of the likelihood that the results obtained in this preliminary acute toxicity test have a direct relevance for protecting human health with respect to the use of AbAEE as a functional food or nutraceutial, an additional upper dose level of 5000 mg/kg b.wt. was used. Since no death was observed, the LD50 could not be estimated but is expected to exceed 5000 mg/kg and this extract could be classified as hazard category 5 (in Globally Harmonized Classification System for Chemical Substances and Mixtures.) or even unclassified for its acute toxicity by the oral route. The sub-chronic oral toxicity study of AbAEE (250 and 500 mg/kg b.wt. day) did not induce significant alterations in almost all hematological and biochemical parameters in rats. Therefore, the overall results of the present study provide supportive data on the use of AbAEE and provide a promising first step for their use as component of new functional foods or as nutraceutical. Though, further studies in both, animals and humans are needed for better evaluation of the food safety of this extract.Ministerio de Economía y Competitividad (MINECO). España IPT- 2011-1418-060000FEDER IPT- 2011-1418-06000

pH and ion-selective swelling behaviour of keratin and keratose 3D hydrogels

The oxidation of keratin hydrogels was optimized aiming to obtain keratose hydrogels while maintaining the original 3D structure and pH-responsive behaviour. In addition, we present a comparative study of their dual-stimuli responsive behaviour regarding the pH-responsiveness and their previously non-described ion selective responsiveness. Keratose and keratin hydrogels showed similar swellings when contracted at low pH, and the former showed steeper expansion and higher swelling than the latter at high pH. In addition, both hydrogels showed selective responsiveness toward Ca2+ ions when expanded, and toward Cu2+ ions when contracted. IR, Raman, ss-NMR, HRMAS NMR, SAXS, and thermal characterization demonstrated that oxidation does not interfere with the stimuli-responsive mechanisms related to protein conformation. The higher swelling of keratose hydrogels would be originated in the increase of the mobility of the chains after oxidation coupled to the hydration of sulfonic acid groups.Fil: Galaburri, Gonzalo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica Instrumental; ArgentinaFil: Peralta Ramos, María Luz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica Instrumental; ArgentinaFil: Lazaro Martinez, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Fernández de Luis, Roberto. No especifíca;Fil: Arriortua, María Isabel. Universidad del País Vasco; EspañaFil: Villanueva, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Copello, Guillermo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentin

Water quality assessment of the Burgos stream micro-basin (San Pedro, Buenos Aires Province) impacted by rural activities

En la región Pampeana (Argentina) se han producido profundos cambios en los agroecosistemas como resultado de los diversos contaminantes generados por las actividades agrícolas y ganaderas. El objetivo del pre-sente trabajo fue evaluar la calidad de las aguas de la microcuenca del arroyo Burgos (San Pedro, Provincia de Buenos Aires) a través de la aplicación de índices de calidad de aguas (ICAs), indicadores de contaminación fecal y bioensayos con algas. Se llevaron a cabo tres muestreos en el año 2015 y se seleccionaron seis sitios de muestreo, cuatro a lo largo de un arroyo tributario de orden 1, y dos en el arroyo Burgos. Se utilizaron dos índices de calidad ambiental: el ICA1, cuyas variables fueron temperatura, OD y NH4+, y el ICA2, cuyas variables fueron pH, OD, temperatura, nitratos, PRS y coliformes fecales. Según el ICA1, la calidad del agua osciló entre polución leve a muy elevada, y según el ICA2, fue de regular a pésima. La concentración de microorganismos indicadores de contami-nación fecal fue similar en todas las muestras, mientras que se observaros diferencias significativas en las concen-traciones de Salmonella spp. Según el análisis de correlación, las precipitaciones participarían en el transporte de microorganimos coliformes a las aguas superficiales a través de procesos de escorrentía superficial. Por otra parte, la inhibición del crecimiento algal no estaría relacionada con el glifosato, cuyas concentraciones fueron de entre 0,35 y 13,57 μg/L. Los resultados sugieren que la aplicación de diferentes indicadores podría ser una herramienta útil para evaluar la calidad ambiental de aguas superficiales de la llanura pampeana, en particular los índices que incluyan la concentración de microorganimos coliformes en su ecuación.The Pampas region (Argentina) have suffered profound changes in the agroecosystems as a result of many pollutants generated by agricultural and livestock activities. The objective of this study was to evaluate the water quality of a microbasin belonging to the Burgos stream (San Pedro, Province of Buenos Aires) through the application of water quality indexes (ICAs), faecal contamination indica-tors and algae bioassays. Three samplings were carried out in 2015 and six sampling sites were selected, four along the tributary stream of order 1, and two in the stream. Two ICAs were used: ICA1, whose variables were temperature, OD and NH4+, and ICA2, whose variables were pH, OD, temperature, nitrates, PRS and faecal coliforms. According to the ICA1, water quality ranged from slight to very high pollution, and according to the ICA2, from regular to dreadful quality. The concentration of faecal indicators microorganisms was similar in all the samples, while significant differences were observed in the concentrations of Salmonella spp. According to the correlation analysis, precipitation would participate in the transport of coliform microorganisms to surface waters through surface runoff processes. On the other hand, the inhibition of algal growth would not be related to glyphosate, whose concentrations were between 0.35 and 13.57 μg/L. The results suggest that the application of different indicators could be a very useful tool to evaluate the environmental quality of surface waters from the Pampas plain, in particular the use of indexes including coliform microorganisms in the calculation equation.Fil: Magdaleno, Anahí. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paz, Marta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Mantovano, Julian Gonzalo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: de Cabo, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Bollani, Sabrina Natalia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Chagas, Celio Ignacio. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Nuñez, Lidia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Tornello, Carina Sandra. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Moretton, Juan Agustin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin