39 research outputs found
Agrocombustibles: ¿Otro negocio es posible?
Hoy en día, los agrocombustibles (principalmente biodiesel y bioetanol) son objeto de políticas públicas e incentivos, y se ha acelerado su producción a gran escala, con la intención de reducir las emisiones de gases de efecto invernadero, y por tanto contribuir a la mitigación del cambio climático. Las y los autores de este libro integran el Grup de Bionegocis, un espacio multidisciplinario impulsado desde la Campaña “No te Comas el Mundo”, que investiga en Cataluña desde el año 2007 sobre la temática de los agrocombustibles. El principal objetivo de esta publicación se ubica en profundizar algunos aspectos con el objetivo de brindar herramientas de reflexión y de acción. Pretende responder a preguntas tales como: ¿Qué son los agrocombustibles? ¿Es positivo su rendimiento energético? ¿Cuál es la huella hídrica de estos carburantes? ¿Son realmente una respuesta ante el calentamiento global? ¿De dónde proviene la materia prima? ¿Mejoran las condiciones de vida en los países del Sur? ¿Cuáles son los intereses corporativos en este rubro? ¿Generarán los agrocombustibles una mayor Deuda ecológica? ¿Es la segunda generación una respuesta adecuada? ¿Qué perspectivas tenemos ante la Soberanía alimentaria y la Soberanía energética?Peer reviewe
Obesity Indexes and Total Mortality among Elderly Subjects at High Cardiovascular Risk: The PREDIMED Study
BackgroundDifferent indexes of regional adiposity have been proposed for identifying persons at higher risk of death. Studies specifically assessing these indexes in large cohorts are scarce. It would also be interesting to know whether a dietary intervention may counterbalance the adverse effects of adiposity on mortality.MethodsWe assessed the association of four different anthropometric indexes (waist-to-height ratio (WHtR), waist circumference (WC), body mass index (BMI) and height) with all-cause mortality in 7447 participants at high cardiovascular risk from the PREDIMED trial. Forty three percent of them were men (55 to 80 years) and 57% were women (60 to 80 years). All of them were initially free of cardiovascular disease. The recruitment took place in 11 recruiting centers between 2003 and 2009.ResultsAfter adjusting for age, sex, smoking, diabetes, hypertension, intervention group, family history of coronary heart disease, and leisure-time physical activity, WC and WHtR were found to be directly associated with a higher mortality after 4.8 years median follow-up. The multivariable-adjusted HRs for mortality of WHtR (cut-off points: 0.60, 0.65, 0.70) were 1.02 (0.78–1.34), 1.30 (0.97–1.75) and 1.55 (1.06–2.26). When we used WC (cut-off points: 100, 105 and 110 cm), the multivariable adjusted Hazard Ratios (HRs) for mortality were 1.18 (0.88–1.59), 1.02 (0.74–1.41) and 1.57 (1.19–2.08). In all analyses, BMI exhibited weaker associations with mortality than WC or WHtR. The direct association between WHtR and overall mortality was consistent within each of the three intervention arms of the trial.ConclusionsOur study adds further support to a stronger association of abdominal obesity than BMI with total mortality among elderly subjects at high risk of cardiovascular disease. We did not find evidence to support that the PREDIMED intervention was able to counterbalance the harmful effects of increased adiposity on total mortality.Trial RegistrationControlled-Trials.com ISRCTN3573963
Natural History of MYH7-Related Dilated Cardiomyopathy
BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare
Dietary inflammatory index and anthropometric measures of obesity in a population sample at high cardiovascular risk from the PREDIMED trial
The dietary inflammatory index (DII) is a new tool to assess the inflammatory potential of diet. We aimed to determine the association between the DII and body mass index (BMI), waist circumference and waist to height ratio (WHtR). We conducted a cross-sectional study of 7,236 participants recruited into the PREDIMED trial (PREvención con DIeta MEDiterránea). Information from a validated 137-item food frequency questionnaire was used to calculate energy, foods and nutrients. A 14-item dietary screener was used to assess adherence to the Mediterranean diet (MeDiet). Sex-specific multivariable linear regression models were fitted to estimate differences (and 95% confidence intervals) in BMI, waist circumference and WHtR across quintiles of the DII. All nutrient intakes, healthy foods and adherence to the MeDiet were higher in the quintile with lowest DII score (more anti-inflammatory values) except for animal protein, saturated and monounsaturated fat. Though an inverse association between DII and total energy was apparent, the DII was associated with higher average BMI, waist circumference and WHtR after adjusting for known risk factors. The adjusted difference in WHtR for women and men between the highest and lowest quintile of DII was 1.60% (95% CI 0.87-2.33) and 1.04% (95% CI 0.35-1.74), respectively. Pro-inflammatory scores remained associated with obesity after controlling for the effect that adherence to a MeDiet had on inflammation. In conclusion, this study shows a direct association between the DII and indices of obesity and supports the hypothesis that diet may have a role in the development of obesity through inflammatory modulation mechanisms
Natural History of MYH7-Related Dilated Cardiomyopathy
BACKGROUND Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVES We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 +/- 19.2 years) recruited from 29 international centers. RESULTS At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% +/- 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of <= 35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation
Thermoformable and recyclable CFRP pultruded profile manufactured from an epoxy vitrimer
In the present work a recyclable and reprocessable vitrimer suitable for pultrusion process has been formulated and a pultruded profile reshaped by thermoforming has been manufactured therefrom. A DGEBA epoxy resin with medium range viscosity and a bis(a-aminophenyl disulfide) as dynamic crosslinker were used for the synthesis of the vitrimer. The thermal stability was studied by thermogravimetric analysis (TGA) and curing behaviour and curing kinetics were studied by means of dynamic scanning calorimeter (DSC) and rheology measurements. Mechanical properties of the dynamic resins and its counterpart epoxy resin and of the fabricated carbon fibre reinforced polymers (CFRP) were determined. The dynamic resin showed a fast stress relaxation at temperatures above 150 °C. Finally, as a proof of concept, mechanical recyclability and the thermoforming of the vitrimer-based pultruded profile have been validated
Aero Grade Epoxy Vitrimer towards Commercialization
Traditional crosslinked aero grade epoxy resins have excellent thermal-mechanical properties
and solvent resistance, but they cannot be remolded, recycled, or repaired. Vitrimers can be
topologically rearranged via an associative exchange mechanism, endowing them with thermoplasticity.
Introducing dynamic bonds into crosslinked networks to obtain more sustainable thermosets
is currently an interesting research topic. While recent research into vitrimers has indicated many
advantages over traditional thermosets, an important shortcoming has been identified: susceptibility
to creep at service temperature due to the dynamic bonds present in the network. In addition,
designing aero grade epoxy vitrimers (similar to RTM6 resin) still remains a challenge. Herein, low
creep aero grade epoxy vitrimer with thermal and mechanical properties similar to those of aero
grade epoxy resins and with the ability to be recyclable, repairable, and reprocessable, has been
prepared. In this manuscript, we demonstrate that aero grade epoxy vitrimer with reduced creep can
be easily designed by the introduction of a certain fraction of permanent crosslinks, without having a
negative effect on the stress relaxation of the material. Subsequently, the mechanical and relaxation
properties were investigated and compared with those of classical aero grade epoxy resin. A high Tg
(175 C) epoxy vitrimer was obtained which fulfilled all mechanical and thermal specifications of
the aero sector. This work provides a simple network design to obtain aero grade epoxy resins with
excellent creep resistance at elevated temperatures while being sustainable.This research has received funding from the European Union’s Horizon 2020 research and
innovation program under grant agreement No 769274, “AIRPOXY”
Thermoforming of thermoset composites manufactured by pultrusion
In this work the development of a profile manufactured by pultrusion and thereafter curved by thermoforming is presented. The pultrusion profile is based on a new thermostable epoxy resin with dynamic bonds capable of being reprocessed, repaired and recycled thanks to the incorporation of reversible links within its reticulated structure (3R Technology). Being a resin that contains dynamic bonds, the cured composite shows unexpected properties for thermosetting materials.
In a first phase, a new resin/hardener formulation processable by pultrusion with a viscosity, adhesion to the fibre and speed of curing similar to a conventional formulation have been developed and in a second phase, taking into account the properties of the new composite material, the parameters of the thermoforming process (pressure, temperature or speed of thermoforming) have been analysed and optimized.
Thanks to the combination of pultrusion and thermoforming processes, longitudinal 3R composite profiles acquire a new curved geometry defined by the design of a mould. In this way, the thermoforming of the straight profiles will allow manufacturing curved parts from profiles of thermostable composites with high mechanical performance manufactured by pultrusion in medium-high rates, typical of the automotive sector. Additionally, it will be shown that the profiles manufactured using these composites can be recycled, reducing the amount of waste generated and offering these materials a second useful life