415 research outputs found

    Comparative study on properties of starch films obtained from potato, corn and wheat using 1-ethyl-3-methylimidazolium acetate as plasticizer

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    Starch films are gaining attention as substitutes of synthetic polymers due to their biodegradability and low cost. Some ionic liquids have been postulated as alternatives to glycerol, one of the best starch plasticizers, due to their great capacity to form hydrogen bonds with starch and hence great ability of preventing starch retrogradation and increasing film stability. In this work, [emim+][Ac−]-plasticized starch films were prepared from potato, corn and wheat starch. The effect of starch molecular structure in terms of granular composition (amylose and phosphate monoester contents) and molecular weight (Mw) on film properties was evaluated. Potato starch films were the most amorphous because of the higher Mw and phosphate monoester content of potato starch, both contributing to a lower rearrangement of the starch chains making the crystallization process difficult. In contrast, corn and wheat starches lead to more crystalline films because of their lower Mw, which may imply higher mobility and crystal growth rate, and lower phosphate monoester content. This more crystalline structure could be the responsible of their better mechanical properties. [emim+][Ac−] can be considered suitable for manufacturing starch films showing corn and wheat starch films similar properties to synthetic low-density polyethylene, but involving a simple and environmentally-friendly process.This work was partially supported from the European Commission, European-Union and Ministerio de Economía y Competitividad (MINECO), Spain (Ref. CTQ2016-78246-R) and Generalitat Valenciana (Project PROMETEOII/2014/007). M.G. Montalbán acknowledges support from Ministerio de Economía y Competitividad (MINECO) (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081)

    ¿Estamos de acuerdo con la calidad técnica de nuestras radiografías de tórax? Un radiólogo, un técnico especialista en radiodiagnóstico y un médico de familia intentan corroborarlo

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    ObjetivoValorar el grado de concordancia en la interpretación de la calidad técnica de las radiografías de tórax de un centro de salud entre el técnico especialista en radiodiagnóstico (TER), el médico de familia y el radiólogo.DiseñoEstudio transversal.EmplazamientoAtención primaria. Centro de Salud de Cartuja en Granada.ParticipantesPacientes del Centro de Salud de Cartuja con estudio radiológico simple de tórax durante 2002. Mediante muestreo aleatorio simple se seleccionaron 150 estudios. Se rechazaron 2 por tratarse de exploraciones repetidas del mismo paciente y 7 porque no presentaban una calidad mínima. La muestra final fue de 141 exploraciones.Mediciones principalesLos observadores cumplimentaron independientemente, para cada exploración, un protocolo de 11 ítems sobre calidad técnica de la imagen. Para cada ítem se calculó el índice kappa entre parejas de observadores, así como el índice kappa global.ResultadosEl 96% de las exploraciones fuerealizado con placas radiográficas de gran tamaño (35×43). Sólo en 2 preguntas hubo una concordancia aceptable o buena entre los 3 observadores (kappa=0,559-0,858). En 5 preguntas, la concordancia fue homogéneamente baja (kappa=0,034-0,375). En algunas preguntas se apreció una fuerte discrepancia entre la valoración del TER y la realizada por los otros 2 observadores.ConclusionesLa concordancia general puede considerarse baja, aunque algo mayor entre el radiólogo y el médico de familia que entre cada uno de éstos y el TER. Esto plantea la necesidad de mejorar la formación de los profesionales en cuanto a la valoración de la calidad técnica de las imágenes. Además, se detecta un gasto innecesario de placas radiográficas de gran tamaño.ObjectiveTo appraise the degree of concordance in the interpretation of the technical quality of chest x-rays at a health centre between an expert in x-ray diagnosis, a family doctor, and a radiologist.DesignTransversal study.SettingPrimary care. Cartuja Health Centre, Granada, Spain.ParticipantsPatients at the Cartuja Health Centre who had a simple chest x-ray in 2002. 150 studies were chosen by simple randomised sampling.Two were rejected because they dealt with a repeat examination of the same patient and seven because they did not reach minimum quality. The final sample was 141 x-rays.Main measurementsThe observers filled in independently, for each examination, an 11- item protocol on the technical quality of the images. The kappa index between pairs of observers was calculated for each item, as was the overall kappa index.Results96% of the examinations were conducted with large x-ray plates (35×43). There was only acceptable or good concordance between the 3 observers in 2 questions (kappa, 0.559-0.858). In 5 questions concordance was homogeneously low (kappa, 0.034-0.375). In some questions there was a strong discrepancy between the appraisal of the expert and that of the 2 other observers.ConclusionsGeneral concordance can be considered low, although it is somewhat greater between the radiologist and the family doctor than between either of these and the expert. This poses the need to improve professional training in evaluation of the technical quality of images. In addition, there was unnecessary expense in large-size x-ray plates

    Preparation and characterization of 33-S samples for 33-S(n,alpha)30-Si cross-section measurements at the n_TOF facility at CERN

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    Thin 33S samples for the study of the 33S(n,a)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.Ministerio de Economía y Competitividad de España-FPA2013-47327- C2-1-R, FPA2014-53290-C2-2-P, FPA2016-77689-C2-1-RJunta de Andalucía-P11-FQM-8229Ministerio de Economía y Empresa de España (Fondos FEDER)-FIS2015-69941-C2-1-PAECC (Asociación Española Contra el Cáncer)-PS16163811POR

    ERCP and splenic injury

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    Abstractendoscopic Retrograde Colangiopancreatography (eRCP) is an invasive procedure with important complications that occurs in 5%-10% of the cases. The most frequent procedure related complications are: acute pancreatitis, hemorrhage, perforation and infection. an infrequent but potentially life threatening eRCP complication is the splenic injury, with very few cases reported in the literature. We report a patient with cholecholithiasis and biliary pancreatitis who was diagnosed with a subcapsular splenic laceration a few hours after an eRCP. Clinicians should be alerted to this potential post-procedure complication associated with eRCP

    Influence of Starch Composition and Molecular Weight on Physicochemical Properties of Biodegradable Films

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    Thermoplastic starch (TPS) films are considered one of the most promising alternatives for replacing synthetic polymers in the packaging field due to the starch biodegradability, low cost, and abundant availability. However, starch granule composition, expressed in terms of amylose content and phosphate monoesters, and molecular weight of starch clearly affects some film properties. In this contribution, biodegradable TPS films made from potato, corn, wheat, and rice starch were prepared using the casting technique. The effect of the grain structure of each starch on microstructure, transparency, hydration properties, crystallinity, and mechanical properties of the films, was evaluated. Potato starch films were the most transparent and corn starch films the most opaque. All the films had homogeneous internal structures—highly amorphous and with no pores, both of which point to a good starch gelatinization process. The maximum tensile strength (4.48–8.14 MPa), elongation at break (35.41–100.34%), and Young’s modulus (116.42–294.98 MPa) of the TPS films were clearly influenced by the amylose content, molecular weight, and crystallinity of the film. In this respect, wheat and corn starch films, are the most resistant and least stretchable, while rice starch films are the most extensible but least resistant. These findings show that all the studied starches can be considered suitable for manufacturing resistant and flexible films with similar properties to those of synthetic low-density polyethylene (LDPE), by a simple and environmentally-friendly process.This work was partially supported by the European Commission (FEDER/ERDF), the Spanish MINECO (Ref. CTQ2016-78246-R), and Generalitat Valenciana (Project PROMETEOII/2014/007). M.G.M. acknowledges support from MINECO (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081)

    Study of the behavior of biodegradable starch/polyvinyl alcohol/rosin blends

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    Biodegradable potato starch/PVA samples containing different concentrations of rosin were prepared by melt-mixing in order to study the enhancement of the properties of native starch films. Glycerol and polyvinyl alcohol (PVA) are commonly used as plasticizers of starch. Their relatively low molecular weight (compared with starch) contributes to a good processability. Rosin is a renewable product whose incorporation in the starch/PVA matrix induces processing aid and reinforcing effects. Its relatively high molecular weight might prevent its migration to the surface of the final product. Water content, solubility in water, mechanical properties, microstructure and dynamic mechanical analysis of the samples were studied. The addition of 8% rosin to starch/PVA blends led to tensile strength values higher than 10 MPa and elongation at break values close to 2000%, values comparable to those offered by conventional polymers used in food packaging, for example LDPE. Furthermore, starch compounds have low cost and high biodegradability.This work was partially supported from the European Commission (FEDER/ERDF) and the Spanish MINECO (Ref. CTQ2016-78246-R) and Generalitat Valenciana (Project PROMETEOII/2014/007). M.G. Montalbán acknowledges support from MINECO (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081)

    First experiment: Fragmentation of ions relevant for space and therapy

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    Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon target

    Higher socioeconomic status is related to healthier levels of fatness and fitness already at 3 to 5 years of age: The PREFIT project: Relation between socioeconomic status, fatness and fitness in preschoolers

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    This study aimed to analyse the association between socioeconomic status (SES) and fatness and fitness in preschoolers. 2, 638 preschoolers (3–5 years old; 47.2% girls) participated. SES was estimated from the parental educational and occupational levels, and the marital status. Fatness was assessed by body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Physical fitness components were assessed using the PREFIT battery. Preschoolers whose parents had higher educational levels had lower fatness (P < 0.05). BMI significantly differed across occupational levels of each parent (P < 0.05) and WHtR across paternal levels (P = 0.004). Musculoskeletal fitness was different across any SES factor (P < 0.05), except handgrip across paternal occupational levels (P = 0.05). Preschoolers with high paternal occupation had higher speed/agility (P = 0.005), and those with high or low maternal education had higher VO2max (P = 0.046). Odds of being obese and having low musculoskeletal fitness was lower as SES was higher (P < 0.05). Those with married parents had higher cardiorespiratory fitness than single-parent ones (P = 0.010). School-based interventions should be aware of that children with low SES are at a higher risk of obesity and low fitness already in the first years of life

    Modeling Ecosystems Using P Systems: The Bearded Vulture, a Case Study

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    The Bearded Vulture (Gypaetus barbatus) is an endangered species in Europe that feeds almost exclusively on bone remains of wild and domestic ungulates. In this paper, we present a model of an ecosystem related to the Bearded Vulture in the Pyrenees (NE Spain), by using P systems. The evolution of six species is studied: the Bearded Vulture and five subfamilies of domestic and wild ungulates upon which the vulture feeds. P systems provide a high level computational modeling framework which integrates the structural and dynamic aspects of ecosystems in a comprehensive and relevant way. P systems explicitly represent the discrete character of the components of an ecosystem by using rewriting rules on multisets of objects which represent individuals of the population and bones. The inherent stochasticity and uncertainty in ecosystems is captured by using probabilistic strategies. In order to experimentally validate the P system designed, we have constructed a simulator that allows us to analyze the evolution of the ecosystem under different initial conditions.Ministerio de Educación y Ciencia TIN2006-13425Junta de Andalucía TIC-58
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