166 research outputs found

    Hypercrosslinked materials

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    This chapter describes the chemistry of hypercrosslinked materials, and presents a description of their synthesis, defining physico-chemical features and their most important applications. The synthesis section will examine the different monomers, precursor polymers, reagents and synthetic strategies used to prepare hypercrosslinked materials. Each synthesis section also details the chemical and morphological properties of the hypercrosslinked materials and the main field of application

    Hypercrosslinked materials : preparation, characterisation and applications

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    This review article provides an overview of hypercrosslinking technology. In particular, it covers the preparation and characterisation of hypercrosslinked materials and their applications. The synthesis section examines the different monomers, precursor polymers and reagents used to prepare hypercrosslinked materials, but also the different synthetic approaches disclosed in the literature. The various chemical modification reactions relevant to this area are also reviewed. Several examples of applications for hypercrosslinked materials are described; these applications are grouped into thematic areas such as chromatography, gas storage and the trapping of organic contaminants

    Estudio del inicio y la finalización de la dentición permanente en un grupo de escolares de una población catalana

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    Este estudio pretende observar la erupción de la dentición permanente en niños y niñas residentes en una población de la provincia de Barcelona. La muestra se estudió en cuanto al sexo, la edad y los primeros y segundos molares erupcionados, encontrando que la primera pieza en aparecer es el primer molar a partir de los 5,33 años de edad, y de la misma forma, el segundo molar permanente es el que cierra todo el proceso eruptivo. Se adjuntan tablas para complementar la secuencia eruptiva

    Análisis crítico del programa de cirugía general para alumnos de la carrera de medicina A critical analysis of the subject " General Surgery " for Medical Students

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    Con el Triunfo Revolucionario, Cuba sufre una transformación radical que abarca todos los campos. Dentro de ellos, la Salud Pública, tan desatendida en todos los años anteriores, sufre la transformación tan demandada para dar respuesta a las necesidades de la población, que incluye la Educación Medica Superior, la cual va ha tener la responsabilidad de formar un nuevo egresado capaz de dar cobertura a la población y sus necesidades. En el presente trabajo hacemos un estudio del diseño curricular del Programa de la Asignatura de Cirugía General para Alumnos de 4to año de la Carrera de Medicina. Veinte años después de realizado dicho programa en el marco de los nuevos requerimientos que se le imponen a dicho egresado, analizándolo objetivamente, exponiendo las conclusiones y dando sugerencias con vistas a mejorar el aprovechamiento docente de nuestros alumnos y su desempeño ulterior en la atención Primaria de Salud. Palabras clave: ESTUDIANTES DE MEDICINA, EDUCACIÓN MÉDICA, PROGRAMAS DE ESTUDIO, CIRUGÍA, CURRICULUM. ABSTRACTWith the revolutionary triumph Cuba experiencedmented radical transformations in all fields, Public Health System among them. This field demanded changes to respond to the needs of the population, including High Medical Education, which has had the responsibility of forming a new graduate being able to solve the needs of the people. A curricular design was analyzed for the subject of General Surgery in 4th academic year of the medical major, 20 years teaching the same syllabus requires a new analysis of the objectives considering the skills the students must develop. Conclusions and proposals were expressed in view of improving teaching -learning process and the further performance of the graduate in Primary Health Care. Key words: MEDICAL STUDENTS, MEDICAL EDUCATION, SYLLABUS, SURGERY, CURRICULAR DESIGN

    Análisis crítico del programa de cirugía general para alumnos de la carrera de medicina A critical analysis of the subject " General Surgery " for Medical Students

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    Con el Triunfo Revolucionario, Cuba sufre una transformación radical que abarca todos los campos. Dentro de ellos, la Salud Pública, tan desatendida en todos los años anteriores, sufre la transformación tan demandada para dar respuesta a las necesidades de la población, que incluye la Educación Medica Superior, la cual va ha tener la responsabilidad de formar un nuevo egresado capaz de dar cobertura a la población y sus necesidades. En el presente trabajo hacemos un estudio del diseño curricular del Programa de la Asignatura de Cirugía General para Alumnos de 4to año de la Carrera de Medicina. Veinte años después de realizado dicho programa en el marco de los nuevos requerimientos que se le imponen a dicho egresado, analizándolo objetivamente, exponiendo las conclusiones y dando sugerencias con vistas a mejorar el aprovechamiento docente de nuestros alumnos y su desempeño ulterior en la atención Primaria de Salud. Palabras clave: ESTUDIANTES DE MEDICINA, EDUCACIÓN MÉDICA, PROGRAMAS DE ESTUDIO, CIRUGÍA, CURRICULUM. ABSTRACTWith the revolutionary triumph Cuba experiencedmented radical transformations in all fields, Public Health System among them. This field demanded changes to respond to the needs of the population, including High Medical Education, which has had the responsibility of forming a new graduate being able to solve the needs of the people. A curricular design was analyzed for the subject of General Surgery in 4th academic year of the medical major, 20 years teaching the same syllabus requires a new analysis of the objectives considering the skills the students must develop. Conclusions and proposals were expressed in view of improving teaching -learning process and the further performance of the graduate in Primary Health Care. Key words: MEDICAL STUDENTS, MEDICAL EDUCATION, SYLLABUS, SURGERY, CURRICULAR DESIGN

    ESAR-Net: a collaborative effort to expand the application of wastewater epidemiology in Spain

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    Resumen del trabajo presentado en el SETAC Europe 30th Annual Meeting, celebrado en modalidad virtual del 3 al 7 de mayo de 2020.Data obtained from wastewater analysis can provide rapid and complementary insights in illict drug consumption at community level. Drug use has been assessed through wastewater analysis at national level in, for example, Australia, Belgium, Finland and South Korea and has also provided annually a one week snapshot of illicit drug volumes consumed in European cities (http://www.emcdda.europa.eu/topics/ pods/waste-water-analysis). However, a wastewater monitoring program did not exist in Spain, but leading experts have formed a network (https://www.esarnet.es/) to promote wastewater-based epidemiology at national level and communicate their findings to authorities and policymakers. Within Europe, Spain is an important country of transit of both cocaine and cannabis, due to its cultural, linguistic and colonial ties to Latin America and its proximity to Morocco. The quantity of seized cocaine and cannabis and prevalence of use, locates Spain at the top of Europe. In this work, a national wastewater campaign has been performed to get more insight on the consumption of illicit drugs and NPS within Spain for the first time. Wastewater results from 14 Spanish cities were compared with previously reported data and other national indicators. The cities, located in 7 of the 17 autonomous communities, cover approximately 6 million inhabitants (12.8 of the Spanish population). Untreated wastewater samples were analyzed for urinary biomarkers of amphetamine, methamphetamine, MDMA, cocaine and cannabis. In addition to these conventional drugs, weekend samples were monitored for several new psychoactive substances (NPS) (i.e. phenethylamines and cathinones). The selected NPS are known as possible replacement of these conventional drugs or among those previously reported. Finally, enantiomeric profiling of amphetamine was performed for one city in order to assure the results were due to consumption and not illegal dumping of production residues. This demonstrates another application of wastewater-based epidemiology, which allows to identify the originof drugs in wastewater.This work has been supported by the Spanish State Research Agency (Agencia Estatal de Investigación, AEI) through the “Redes de Excelencia” programme, ESAR-Net, ref. CTM2016-81935-RED

    Cranial biomechanics in basal urodeles: the Siberian salamander (Salamandrella keyserlingii) and its evolutionary and developmental implications

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    Developmental changes in salamander skulls, before and after metamorphosis, afect the feeding capabilities of these animals. How changes in cranial morphology and tissue properties afect the function of the skull are key to decipher the early evolutionary history of the crown-group of salamanders. Here, 3D cranial biomechanics of the adult Salamandrella keyserlingii were analyzed under diferent tissue properties and ossifcation sequences of the cranial skeleton. This helped unravel that: (a) Mechanical properties of tissues (as bone, cartilage or connective tissue) imply a consensus between the stifness required to perform a function versus the fxation (and displacement) required with the surrounding skeletal elements. (b) Changes on the ossifcation pattern, producing fontanelles as a result of bone loss or failure to ossify, represent a trend toward simplifcation potentially helping to distribute stress through the skull, but may also imply a major destabilization of the skull. (c) Bone loss may be originated due to biomechanical optimization and potential reduction of developmental costs. (d) Hynobiids are excellent models for biomechanical reconstruction of extinct early urodeles

    Sources of skill in lake temperature, discharge and ice-off seasonal forecasting tools

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    Despite high potential benefits, the development of seasonal forecasting tools in the water sector has been slower than in other sectors. Here we assess the skill of seasonal forecasting tools for lakes and reservoirs set up at four sites in Australia and Europe. These tools consist of coupled hydrological catchment and lake models forced with seasonal meteorological forecast ensembles to provide probabilistic predictions of seasonal anomalies in water discharge, temperature and ice-off. Successful implementation requires a rigorous assessment of the tools' predictive skill and an apportionment of the predictability between legacy effects and input forcing data. To this end, models were forced with two meteorological datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF), the seasonal forecasting system, SEAS5, with 3-month lead times and the ERA5 reanalysis. Historical skill was assessed by comparing both model outputs, i.e. seasonal lake hindcasts (forced with SEAS5), and pseudo-observations (forced with ERA5). The skill of the seasonal lake hindcasts was generally low although higher than the reference hindcasts, i.e. pseudo-observations, at some sites for certain combinations of season and variable. The SEAS5 meteorological predictions showed less skill than the lake hindcasts. In fact, skilful lake hindcasts identified for selected seasons and variables were not always synchronous with skilful SEAS5 meteorological hindcasts, raising questions on the source of the predictability. A set of sensitivity analyses showed that most of the forecasting skill originates from legacy effects, although during winter and spring in Norway some skill was coming from SEAS5 over the 3-month target season. When SEAS5 hindcasts were skilful, additional predictive skill originates from the interaction between legacy and SEAS5 skill. We conclude that lake forecasts forced with an ensemble of boundary conditions resampled from historical meteorology are currently likely to yield higher-quality forecasts in most cases.</p

    Attribution of global lake systems change to anthropogenic forcing

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    Lake ecosystems are jeopardized by the impacts of climate change on ice seasonality and water temperatures. Yet historical simulations have not been used to formally attribute changes in lake ice and temperature to anthropogenic drivers. In addition, future projections of these properties are limited to individual lakes or global simulations from single lake models. Here we uncover the human imprint on lakes worldwide using hindcasts and projections from five lake models. Reanalysed trends in lake temperature and ice cover in recent decades are extremely unlikely to be explained by pre-industrial climate variability alone. Ice-cover trends in reanalysis are consistent with lake model simulations under historical conditions, providing attribution of lake changes to anthropogenic climate change. Moreover, lake temperature, ice thickness and duration scale robustly with global mean air temperature across future climate scenarios (+0.9 °C °Cair–1, –0.033 m °Cair–1 and –9.7 d °Cair–1, respectively). These impacts would profoundly alter the functioning of lake ecosystems and the services they provide
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