Preparation and Characterisation of Binder-Free All-Cellulose Composites

The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the authorA recent emerging concept of all-cellulose composites within the field of environmentally friendly materials has received increasing attention. The main advantage of these materials is the lack of using additional bonding agents such as polymer resins as in the case of e.g. phenolic resin based panel products or natural fibre reinforced plastics that increase their environmental impact. Two different routes for the production of all-cellulose composites have been followed. The obtained materials were characterised by scanning electron microscopy, X-ray diffraction, flexure and tensile mechanical tests, thermogravimetric analysis, pycnometry and water absorption tests. The first strategy makes use of the selective dissolution method where the cellulose fibre skins are partially dissolved to form a matrix phase that bonds the fibres together, while the strong core fibres are maintained and impart a reinforcing effect to the composites. The influence of the dissolution time, activation time and the fibre source were assessed. It was found that a dissolution time of 18 h led to materials with the best overall mechanical performance (5.5 GPa and 145 MPa for Young’s modulus and tensile strength, respectively), as this time allowed for the dissolution of a sufficient amount of fibre surface to obtain good interfacial bonding between fibres, while keeping a considerable amount of remaining fibre cores that provide a strong reinforcement to the composite, leading to materials that outperform natural fibres reinforced polypropylene composites. Still, the previous methodology has the drawback of using chemical substances of high environmental impact (solvents). In order to overcome this, a new concept in the production of all-cellulose composites is proposed in this work, which makes use of the intrinsic bonding capability between cellulose fibres to enhance the hydrogen bond network in order to produce materials of good mechanical performance. A new experimental procedure was developed, based on the refinement Abstract 5 of cellulose fibres in order to increase their specific surface area, thus increasing the interfibre bonding capability, and achieving materials with excellent mechanical properties, up to 17 GPa and 119 MPa for flexural modulus and strength, respectively, and low water absorption. These new high-performing environmentally friendly materials are based on renewable resources and are 100% recyclable and biodegradable.Financial support from the Engineering and Physical Sciences Research Council through a Technology Strategy Board project REFLECT no. MATH1E2R, under the Design & Manufacture of Sustainable Products Call, is gratefully acknowledged

Preparation and Characterisation of Binder-Free All-Cellulose Composites

A recent emerging concept of all-cellulose composites within the field of environmentally friendly materials has received increasing attention. The main advantage of these materials is the lack of using additional bonding agents such as polymer resins as in the case of e.g. phenolic resin based panel products or natural fibre reinforced plastics that increase their environmental impact. Two different routes for the production of all-cellulose composites have been followed. The obtained materials were characterised by scanning electron microscopy, X-ray diffraction, flexure and tensile mechanical tests, thermogravimetric analysis, pycnometry and water absorption tests. The first strategy makes use of the selective dissolution method where the cellulose fibre skins are partially dissolved to form a matrix phase that bonds the fibres together, while the strong core fibres are maintained and impart a reinforcing effect to the composites. The influence of the dissolution time, activation time and the fibre source were assessed. It was found that a dissolution time of 18 h led to materials with the best overall mechanical performance (5.5 GPa and 145 MPa for Young’s modulus and tensile strength, respectively), as this time allowed for the dissolution of a sufficient amount of fibre surface to obtain good interfacial bonding between fibres, while keeping a considerable amount of remaining fibre cores that provide a strong reinforcement to the composite, leading to materials that outperform natural fibres reinforced polypropylene composites. Still, the previous methodology has the drawback of using chemical substances of high environmental impact (solvents). In order to overcome this, a new concept in the production of all-cellulose composites is proposed in this work, which makes use of the intrinsic bonding capability between cellulose fibres to enhance the hydrogen bond network in order to produce materials of good mechanical performance. A new experimental procedure was developed, based on the refinement of cellulose fibres in order to increase their specific surface area, thus increasing the interfibre bonding capability, and achieving materials with excellent mechanical properties, up to 17 GPa and 119 MPa for flexural modulus and strength, respectively, and low water absorption. These new high-performing environmentally friendly materials are based on renewable resources and are 100% recyclable and biodegradable.Engineering and Physical Sciences Research Council through a Technology Strategy Board project REFLECT no. MATH1E2R, under the Design & Manufacture of Sustainable Products Cal

Impacto de la ecografía volumétrica portátil en el sondaje vesical por retención urinaria en una unidad de medicina interna

Aim: To estimate the impact of the use of portable bladder volumetric ultrasound on bladder catheterization due to suspicion of urinary retention in an internal medicine unit. Methodology: Study of retrospective cohorts, comparing the cohort exposed to the availability of bladder ultrasound, with the not exposed the previous year. All records in the Electronic Medical Record (EHR) of short-term permanent bladder catheters in adult patients admitted to the Internal Medicine hospitalization unit of the University Hospital Fundación Alcorcón (HUFA) during the years 2015 and 2016 were analyzed. The urinary retention frequency is estimated as the cause of the catheterization after the device has been incorporated into the unit and compared with the frequency of catheterization during the same period of the previous year in the same unit. It is estimated that the impact of having this device on the urinary retention frequency is the reason for the catheterization. Results: 134 catheters are included in 113 patients, 62 in the group without ultrasound and 72 in the group with ultrasound. The frequency of catheterizations due to retention is reduced from 47.5% to 21.4% after introducing the ultrasound unit into the unit. This represents a 50% reduction (adjusted RR=0.48; CI95%:0.27-0.84, p=0.01) in the frequency of urinary catheterization for suspected urinary retention.Objetivo: Estimar el impacto que el uso de ecógrafo vesical tiene en los sondajes vesicales por sospecha de retención urinaria de una unidad de Medicina interna.Metodología: Estudio de cohortes retrospectivas, comparando la cohorte expuesta a la disponibilidad del ecógrafo vesical, con la no expuesta el año previo. Se analizan todos los registros en la Historia Clínica Electrónica (HCE) de sondajes vesicales permanentes de corta duración en pacientes adultos que ingresaron en la unidad de hospitalización de Medicina Interna del Hospital Universitario Fundación Alcorcón (HUFA) durante los años 2015 y 2016. Se estima la frecuencia de retención urinaria como causa del sondaje después de la incorporación del dispositivo en la unidad y se compara con la frecuencia en sondajes durante el mismo periodo del año anterior en la misma unidad. Se estima el impacto que disponer de este dispositivo tiene en la frecuencia de retención urinaria como motivo del sondaje.Resultados: Se incluyen 134 sondajes en 113 pacientes, 62 en el grupo sin ecógrafo y 72 en el grupo con ecógrafo. La frecuencia de sondajes por retención se reduce del 47.5% al 21.4% después de introducir el ecógrafo en la unidad. Esto supone una reducción del 50% (RR ajustado= 0.48; IC95%:0.27-0.84, p=0.01) en la frecuencia de sondaje vesical por sospecha de retención urinaria

Design and rationale of a multicentre, randomised, double-blind, placebo-controlled clinical trial to evaluate the effect of vitamin D on ventricular remodelling in patients with anterior myocardial infarction: the VITamin D in Acute Myocardial Infarction (VITDAMI) trial

Introduction:Decreased plasma vitamin D (VD) levels are linked to cardiovascular damage. However, clinical trials have not demonstrated a benefit of VD supplements on left ventricular (LV) remodelling. Anterior ST-elevation acute myocardial infarction (STEMI) is the best human model to study the effect of treatments on LV remodelling. We present a proof-of-concept study that aims to investigate whether VD improves LV remodelling in patients with anterior STEMI. Methods and analysis:The VITamin D in Acute Myocardial Infarction (VITDAMI) trial is a multicentre, randomised, double-blind, placebo-controlled trial. 144 patients with anterior STEMI will be assigned to receive calcifediol 0.266 mg capsules (Hidroferol SGC)/15 days or placebo on a 2:1 basis during 12 months. Primary objective:to evaluate the effect of calcifediol on LV remodelling defined as an increase in LV end-diastolic volume >= 10\% (MRI). Secondary objectives:change in LV end-diastolic and end-systolic volumes, ejection fraction, LV mass, diastolic function, sphericity index and size of fibrotic area; endothelial function; plasma levels of aminoterminal fragment of B-type natriuretic peptide, galectin-3 and monocyte chemoattractant protein-1; levels of calcidiol (VD metabolite) and other components of mineral metabolism (fibroblast growth factor-23 (FGF-23), the soluble form of its receptor klotho, parathormone and phosphate). Differences in the effect of VD will be investigated according to the plasma levels of FGF-23 and klotho. Treatment safety and tolerability will be assessed. This is the first study to evaluate the effect of VD on cardiac remodelling in patients with STEMI. Ethics and dissemination: This trial has been approved by the corresponding Institutional Review Board (IRB) and National Competent Authority (Agencia Espanola de Medicamentos y Productos Sanitarios (AEMPS)). It will be conducted in accordance with good clinical practice (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use-Good Clinical Practice (ICH-GCP)) requirements, ethical principles of the Declaration of Helsinki and national laws. The results will be submitted to indexed medical journals and national and international meetings.The VITDAMI trial is an investigator initiated study, sponsored by the Instituto de Investigacion Sanitaria Fundacion Jimenez Diaz (IIS-FJD). Funding has been obtained from Fondo de Investigaciones Sanitarias (PI14/01567; http://www.isciii.es/) and Spanish Society of Cardiology (http://secardiologia.es/). In addition, the study medication has been provided freely by the pharmaceutical Company FAES FARMA S.A. (Leioa, Vizcaya, Spain; http://faesfarma.com/). This company was the only funder who collaborated in study design (IG-H).S

Effectiveness of Modified Vaccinia Ankara-Bavaria Nordic Vaccination in a Population at High Risk of Mpox: A Spanish Cohort Study

Background: With over 7,500 cases notified since April 2022, Spain has experienced the highest incidence of mpox in Europe. From July 12th onwards, the Modified Vaccinia Ankara-Bavaria Nordic (MVA-BN) smallpox vaccine was offered as pre-exposure prophylaxis for individuals at high-risk of mpox, including those receiving pre-exposure prophylaxis for HIV (HIV-PrEP). Our aim was to assess the effectiveness of one dose of MVA-BN vaccine as pre-exposure against mpox virus (MPXV) infection in persons on HIV-PrEP. Methods: We conducted a national retrospective cohort study between July 12 and December 12, 2022. Individuals ≥18 years, receiving HIV-PrEP as of July 12 and with no previous MPXV infection or vaccination were eligible. Each day, we matched individuals receiving a first dose of MVA-BN vaccine and unvaccinated controls of the same age group and region. We used a Kaplan-Meier estimator and calculate risk ratios (RR) and vaccine effectiveness (VE = 1-RR). Results: We included 5,660 matched pairs, with a median follow-up of 62 days (interquartile range 24-97). Mpox cumulative incidence was 5.6 per 1,000 (25 cases) in unvaccinated and 3.5 per 1,000 (18 cases) in vaccinated. No effect was found during days 0-6 post-vaccination (VE -38.3; 95% confidence interval (95%CI): -332.7; 46.4), but VE was 65% in ≥7 days (95%CI 22.9; 88.0) and 79% in ≥14 days (95%CI 33.3; 100.0) post-vaccination. Conclusions: One dose of MVA-BN vaccine offered protection against mpox in a most-at-risk population shortly after the vaccination. Further studies need to assess the VE of a second dose and the duration of protection over time.S

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

SymC++: un depurador simbólico para C++

En este proyecto se estudia y desarrolla una herramienta basada en depuración simbólica que permite conocer el funcionamiento de programas informáticos sin ser ejecutados en base a observar todas sus posibles ramas de ejecución (hasta un cierto nivel), así como los correspondientes pares entrada-salida. Dicha herramienta está ideada con la idea de ayudar a los estudiantes de iniciación a la programación, y en general a programadores inexpertos a la hora de razonar acerca de la corrección de sus programas. El núcleo de la herramienta está basado en la ejecución simbólica, una de las técnicas más potentes para hacer estudios estáticos del comportamiento de los programas. La ejecución simbólica consiste en el análisis de un programa usando valores simbólicos (o variables) en lugar de valores concretos. Esto permite comprender la ejecución del programa gracias a la observación de los comportamientos de sus diferentes caminos de ejecución, así como determinar las condiciones que deben ser verificadas por los datos de entrada para obtener un resultado particular, y la relación entre los valores ingresados y producidos en la ejecución de un programa. La herramienta desarrollada, denominada SymC++, recibe una serie de parámetros de entrada sobre la función a testear, partiendo de un código C++, obteniendo así información de las distintas ramas generadas. Dichos resultados se generan en formato XML lo cual facilita la portabilidad y escalabilidad del proyecto ofreciendo un depurador que se puede adaptar a diferentes interfaces de usuario

Nanofibrillated cellulose (NFC) as a potential reinforcement for high performance cement mortar composites

In this work, nanofibrillated cellulose (NFC) has been evaluated as a potential reinforcement for cement mortar composites. Two types of vegetable fibres with different composition and properties (cellulose content and microfibrillar angle), sisal, and cotton linters pulps, were initially characterized in order to assess their reinforcement capability. Sisal pulp was found to be most suitable as reinforcement for their brittle cementitious matrix. Nanofibrillated cellulose was produced by the application of a high intensity refining process of the sisal pulp. It was found that 6 hours of refining time was required to obtain the desired nanofibrillation of the fibers. Cement mortar composites reinforced with both the sisal fibers and the nanofibrillated cellulose were prepared, and the mechanical properties were determined under flexural test. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited enhanced flexural properties, but lower values of fracture energy, than the ones reinforced with the conventional sisal fibres.Peer ReviewedPostprint (published version

Propuesta de intervenci\uf3n para una escuela de padres: la comunicaci\uf3n entre padres e hijos adolescentes, factor clave para un buen clima familiar

La comunicaci\uf3n es un elemento clave para generar un buen clima familiar, sin embargo, muchas veces, y especialmente durante el periodo de la adolescencia, puede sufrir un deterioro. Conocer los cambios que se producen en esta etapa evolutiva, as\ued como las necesidades del adolescente puede ser de ayuda para establecer una comunicaci\uf3n m\ue1s emp\ue1tica y eficaz en el hogar. En este art\uedculo se presenta una propuesta de intervenci\uf3n dirigida a padres con hijos adolescentes a trav\ue9s de un taller formativo y pr\ue1ctico con la intenci\uf3n de mantener y/o mejorar la comunicaci\uf3n y el v\uednculo entre ellos, generando as\ued un buen clima familiar y una convivencia positiva. La metodolog\ueda planteada ser\ue1 participativa y de interacci\uf3n propia de las escuelas de padres. A partir del an\ue1lisis del tipo de comunicaci\uf3n que se da en los hogares, se explicar\ue1n los estilos comunicativos invitando a la reflexi\uf3n y facilitando t\ue9cnicas y estrategias para una escucha activa y un di\ue1logo eficaz entre los miembros de la familia. Se animar\ue1 a los padres a compartir vivencias y se profundizar\ue1 en los beneficios de un buen clima familiar

Efecto del grado de fibrilación sobre las propiedades mecánicas de morteros de cemento reforzados con fibras vegetales

En este trabajo se han llevado a cabo la preparación y caracterización de nuevos compuestos a base de morteros de cemento reforzados con fibras celulósicas nanofibriladas. El efecto del grado de fibrilación de las fibras sobre las propiedades mecánicas de los composites resultantes se presenta y analiza en base al tamaño final del refuerzo obtenido según la intensidad del tratamiento mecánico aplicado. Para ello se ha partido de fibras de sisal que han sido sometidas a un pulpeado mecánico suave para obtener las pulpas convencionales y a un pulpeado mecánico muy intenso para obtener celulosa nanofibrilada. Las pastas obtenidas han sido incorporadas y dispersadas homogéneamente en morteros de cemento, para posteriormente curar los compuestos durante 28 días. Finalmente se han determinado las propiedades mecánicas de los compuestos con ensayos de flexión. Los resultados indican como las fibras con un alto grado de fibrilación conducen a compuestos con un mayor módulo y resistencia comparados con los obtenidos con las fibras que únicamente han sido sometidas a un pulpeado mecánico suave.Postprint (published version