Electrochemical Estimation of the Corrosion Rate of Magnesium/Aluminium Alloys

The corrosion rate of AZ31, AZ80, and AZ91D magnesium/aluminium alloys immersed in 3.5 wt.% NaCl was determined comparing gravimetric and electrochemical measurements. The findings revealed that, for all investigated materials, a fraction of the metallic surface exposed to the corrosive medium did not reveal a normal electrochemical response to the applied signal. This may be associated with phenomena such as partial disintegration of specimens into fine metallic particles, electrochemical formation of ions, and/or anomalous chemical attack occurring simultaneously with the normal electrochemical corrosion attack. The abnormal electrochemical behaviour was more evident for lower amounts of aluminium in the bulk composition of the investigated materials. Thus, the electrochemical estimates of pure Mg and the AZ31 alloy were not reliable and tended to underestimate corrosion losses.Peer Reviewe

Bibliotecas abiertas. El programa de visitas de la Biblioteca Valenciana Nicolau Primitiu

En un contexto de reducción de la financiación pública y de cambio de paradigma en el acceso a la información, la supervivencia de las bibliotecas está ligada a un mayor y mejor conocimiento de la ciudadanía de sus colecciones, productos y servicios. En este estudio se analiza el programa de visitas de la Biblioteca Valenciana Nicolau Primitiu, sus características, destinatarios y tipologías, así como los resultados alcanzados hasta ahora.In a context of reduced public funding and a paradigm shift in access to information, the survival of libraries is linked to greater and better knowledge by citizens of their collections, products, and services. This study analyzes the visits program of the Biblioteca Valenciana Nicolau Primitiu, its characteristics, recipients, and typologies, as well as the results achieved so fa

Linear models of activation cascades: analytical solutions and coarse-graining of delayed signal transduction

Cellular signal transduction usually involves activation cascades, the sequential activation of a series of proteins following the reception of an input signal. Here we study the classic model of weakly activated cascades and obtain analytical solutions for a variety of inputs. We show that in the special but important case of optimal-gain cascades (i.e., when the deactivation rates are identical) the downstream output of the cascade can be represented exactly as a lumped nonlinear module containing an incomplete gamma function with real parameters that depend on the rates and length of the cascade, as well as parameters of the input signal. The expressions obtained can be applied to the non-identical case when the deactivation rates are random to capture the variability in the cascade outputs. We also show that cascades can be rearranged so that blocks with similar rates can be lumped and represented through our nonlinear modules. Our results can be used both to represent cascades in computational models of differential equations and to fit data efficiently, by reducing the number of equations and parameters involved. In particular, the length of the cascade appears as a real-valued parameter and can thus be fitted in the same manner as Hill coefficients. Finally, we show how the obtained nonlinear modules can be used instead of delay differential equations to model delays in signal transduction.Comment: 18 pages, 7 figure

Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 °C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH)2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH)2. A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formedThanks to the MCYT for the financial support given to this work (Project MAT2006-13179-C02-01-02)Peer reviewe

Comportamiento del infarto agudo del miocardio en el hospital “León Cuervo Rubio”, 2006.

Se realizó un estudio descriptivo retrospectivo a los pacientes con infarto agudo del miocardio ingresados de enero de 2006 a enero de 2007, con el objetivo de describir el comportamiento de estos pacientes, identificar los factores de riesgos, los motivos de ingresos, la incidencia según edad, color de la piel y sexo. El sexo más afectado fue el masculino con 36 casos. La mayor incidencia ocurre entre los 66 y los 74 años. El principal factor de riesgo fue la hipertensión arterial con 21 pacientes. El color de la piel que más predominó fue el color blanco con 47 casos. El principal motivo de ingreso fue el dolor precordial seguido de la taquicardia. Prevaleció el infarto no Q y no ocurrieron complicaciones en la mayoría de los casos. Este estudio constituye un pilar vital en las futuras tomas de decisiones para la creación de una Unidad de Cuidados Intensivos Coronarios (UCIC) en hospital donde se realizó la investigación

Multimorbidity clusters in patients with chronic obstructive airway diseases in the EpiChron Cohort

Chronic obstructive airway diseases such as chronic obstructive pulmonary disease (COPD), asthma, rhinitis, and obstructive sleep apnea (OSA) are amongst the most common treatable and preventable chronic conditions with high morbidity burden and mortality risk. We aimed to explore the existence of multimorbidity clusters in patients with such diseases and to estimate their prevalence and impact on mortality. We conducted an observational retrospective study in the EpiChron Cohort (Aragon, Spain), selecting all patients with a diagnosis of allergic rhinitis, asthma, COPD, and/or OSA. The study population was stratified by age (i.e., 15–44, 45–64, and = 65 years) and gender. We performed cluster analysis, including all chronic conditions recorded in primary care electronic health records and hospital discharge reports. More than 75% of the patients had multimorbidity (co-existence of two or more chronic conditions). We identified associations of dermatologic diseases with musculoskeletal disorders and anxiety, cardiometabolic diseases with mental health problems, and substance use disorders with neurologic diseases and neoplasms, amongst others. The number and complexity of the multimorbidity clusters increased with age in both genders. The cluster with the highest likelihood of mortality was identified in men aged 45 to 64 years and included associations between substance use disorder, neurologic conditions, and cancer. Large-scale epidemiological studies like ours could be useful when planning healthcare interventions targeting patients with chronic obstructive airway diseases and multimorbidity

Cohort Profile: The epidemiology of chronic diseases and multimorbidity. The EpiChron cohort study

Why was the cohort set up? Greater life expectancy in Europe over the past few decades has been translated into an increasing burden of chronic diseases that accumulate as the population ages, whereas acute infectious diseases have been progressively pushed into the background. The incidence of conditions such as hypertension, obesity and asthma has increased dramatically worldwide, and cancer, diabetes and respiratory and cardiovascular diseases are responsible for almost 70% of global deaths. Concurrently, the prevalence of multimorbidity (as of people affected by more than one chronic disorder) is also increasing and appears as the most common chronic condition at present. Multimorbidity affects almost 3 in 4 individuals aged 65 years and older, although it represents a problem not only for the elderly but also for adult and even young populations, at whom prevention strategies should aim. People affected by multimorbidity often experience fragmentation of care, greater and inadequate use of health services and polypharmacy, which in turn may increase the risk of low adherence and adverse drug reactions. All of this leads to individuals’ quality of life deterioration and higher risk of mortality. Besides, handling patients with multimorbidity represents a daily challenge for physicians and health systems..