Corrosion experiments in metals and alloys. Comparison between field and laboratory tests: a research work in high school degree

The aim of this work is to show the experimental results corresponding to comparative corrosion studies carried out with five commercially pure different metals (iron, lead, zinc, aluminum, and copper) together with the alloy stainless steel 316. Field tests were performed in two different environments. The first, urban environment was represented by a zone corresponding to metropolitan area of Barcelona (Spain). The second environment, a marine environment, was selected on the coast line of the same metropolitan area. The time corresponding to field tests was a half year and the subsequent results were compared with laboratory accelerated tests from robotized equipment, chosen to simulate urban and marine environments, by using aqueous sodium hydrogen sulphite and sodium chloride solutions, respectively. Equivalent time between both field and accelerated tests has been obtained. The results allow a good correlation between both types of exposures and make it possibleto study morphological and quantitative aspects of corrosion process, as well as the influence of different variables that influence the corrosion resistance of each metal and alloy. The main feature of this work is the collaboration between high school students and university faculty , to illustrate, by active participation, the concept of “research work”, in the second year of high school, just before beginning their higher education studies.Postprint (published version

Corrosion experiments in metals and alloys. Comparison between field and laboratory tests: a research work in high school degree

The aim of this work is to show the experimental results corresponding to comparative corrosion studies carried out with five commercially pure different metals (iron, lead, zinc, aluminum, and copper) together with the alloy stainless steel 316. Field tests were performed in two different environments. The first, urban environment was represented by a zone corresponding to metropolitan area of Barcelona (Spain). The second environment, a marine environment, was selected on the coast line of the same metropolitan area. The time corresponding to field tests was a half year and the subsequent results were compared with laboratory accelerated tests from robotized equipment, chosen to simulate urban and marine environments, by using aqueous sodium hydrogen sulphite and sodium chloride solutions, respectively. Equivalent time between both field and accelerated tests has been obtained. The results allow a good correlation between both types of exposures and make it possibleto study morphological and quantitative aspects of corrosion process, as well as the influence of different variables that influence the corrosion resistance of each metal and alloy. The main feature of this work is the collaboration between high school students and university faculty , to illustrate, by active participation, the concept of “research work”, in the second year of high school, just before beginning their higher education studies

Virological outcome among HIV infected patients transferred from pediatric care to adult units in Madrid, Spain (1997–2017)

The aim of this transversal study was to describe the virological and immunological features of HIV-infected youths transferred from pediatric to adult care units since 1997 vs. the non-transferred patients from the Madrid Cohort of HIV-infected children and adolescents in Spain. We included 106 non-transferred and 184 transferred patients under clinical follow-up in 17 public hospitals in Madrid by the end of December 2017. Virological and immunological outcomes were compared in transferred vs. non-transferred patients. ART drug resistance mutations and HIV-variants were analyzed in all subjects with available resistance pol genotypes and/or genotypic resistance profiles. Among the study cohort, 133 (72.3%) of 184 transferred and 75 (70.7%) of 106 non-transferred patients had available resistance genotypes. Most (88.9%) of transferred had ART experience at sampling. A third (33.3%) had had a triple-class experience. Acquired drug resistance (ADR) prevalence was significantly higher in pretreated transferred than non-transferred patients (71.8% vs. 44%; p = 0.0009), mainly to NRTI (72.8% vs. 31.1%; p < 0.0001) and PI (29.1% vs. 12%; p = 0.0262). HIV-1 non-B variants were less frequent in transferred vs. non-transferred (6.9% vs. 32%; p < 0.0001). In conclusion, the frequent resistant genotypes found in transferred youths justifies the reinforcement of HIV resistance monitoring after the transition to avoid future therapeutic failures

Psychological risk factors and cardiovascular disease: Is it all in your head?

Psychological stress has been shown to be associated with cardiovascular disease. Over the past few decades, there has been an increasing interest in this relationship, leading to a growing pool of clinical and epidemiological data on the subject. Psychological stress has multiple etiologies, which include behavioral causes, acute events or stressors, and/or chronic stress. Cardiac rehabilitation and exercise therapy have been shown to provide protection in primary and secondary coronary heart disease prevention, as well as improve overall morbidity and mortality. In this article, we review the available data regarding the association between psychological stress and cardiovascular disease, as well as the impact of cardiac rehabilitation and exercise therapy on psychological stress-related cardiovascular events