Microfluidic model of bubble lodging in microvessel bifurcations

The lodging mechanisms and dynamics of cardiovascular gas bubbles are investigated in microfluidic model bifurcations made of poly(dimethylsiloxane). This work is motivated by gas embolotherapy for the potential treatment of cancer by tumor infarction. The results show that the critical driving pressure below which a bubble will lodge in a bifurcation is significantly less than the driving pressure required to dislodge it. From the results the authors estimate that gas bubbles from embolotherapy can lodge in vessels 20 μm20μm or smaller in diameter, and conclude that bubbles may potentially be used to reduce blood flow to tumor microcirculation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87802/2/244103_1.pd

Hydraulic fracture behavior in the presence of hydrogen in notched miniature cylindrical specimens of a 42CrMo4 steel

The influence of internal hydrogen on the mechanical behavior of the 42CrMo4 steel grade has been evaluated by means of internal pressure fracture tests performed on hydrogen precharged notched cylindrical specimens. The notched cylindrical specimens were precharged in a 1 M H2SO4 solution + 0.25 g/l As2O3 for 3 h and 1.2 mA/cm2. Thereupon, hydraulic fracture tests were done under different ramps of pressure: 208, 100, 52, 35 and 25 MPa/h, respectively. Hydrogen content introduced into the notched cylindrical specimens (∼1 ppm) was determined by thermal desorption analysis (TDA), using a LECO DH 603 hydrogen analyser. Hydrogen damage was observed as testing time increased until 2 h. The burst pressure is reduced around 28 % while the Notch Mouth Opening Displacement decreased around 50 %. Hydrogen embrittlement susceptibility is discussed through the hydrogen embrittlement micromechanisms.The authors would like to thank the Spanish Government for the financial support received to perform the research projects RTI2018-096070-B-C33 and PID2021-124768OB-C21. L.B. Peral is grateful for his Margarita Salas Postdoctoral contract (Ref.: MU-21-UP2021-030) funded by the University of Oviedo through the Next Generation European Union

Influence of hydrogen on the hydraulic fracture behavior of a 42CrMo4 steel welds: Effect of the prior austenite grain size

The influence of hydrogen on the mechanical behavior of a quenched and tempered 42CrMo4 steel has been evaluated by means of high internal pressure fracture tests carried out on hydrogen precharged notched cylindrical specimens. The notched cylindrical specimens were precharged in a 1 M H2SO4 + 0.25 g/l As2O3 solution for 3 h with 1.2 mA/cm2. Hydraulic fracture tests were performed at different loading rates. Hydrogen embrittlement resistance increased with grain size refinement although the fine grained specimen had a higher hydrogen content than the coarse grained one. Fractographic analysis showed hydrogen enhanced decohesion fracture was less pronounced with decreasing grain size. Hydrogen embrittlement susceptibility is discussed in terms of the prior austenite grain size (PAGS) and the operative fracture mechanisms.The authors would like to thank the Spanish Government for the financial support received to perform the research projects TED2021-130413B-I00 and PID2021-124768OB-C21. This work was supported by the Regional Government of Castilla y León (Junta de Castilla y León) and by the Ministry of Science and Innovation MICIN and the European Union Next Generation EU/PRTR (MR5W.P3) and PRTR (MR4W.P2). L.B. Peral is grateful for his Margarita Salas Postdoctoral contract (Ref.: MU-21-UP2021-030) funded by the University of Oviedo through the Next Generation European Union

Parameter Optimisation in Selective Laser Melting on C300 Steel

Additive manufacturing (AM) of metallic materials is increasingly being adopted in numerous sectors, such as biomedicine, aerospace or automotive industries, due to its versatility in the creation of complex geometries and the minimisation of material waste when compared to traditional subtractive methods. In order to ensure a reliable operation of these parts, however, an in-depth study of the effect of additive manufacturing on mechanical properties, including tensile, fatigue and fracture resistance, is necessary. Among the vast number of methods and materials, this project is focused in one of the most promising techniques for the industry: Selective Laser Melting (SLM) for the production of a tools steel, in particular C300 steel components for the automotive sector. The main objective of this paper is to optimise some of the key parameters in the printing process, such as laser power, laser speed and hatch spacing. These variables are essential to obtain parts with good resistance. To that purpose, tensile tests were performed in 3D printed specimens, and then elastoplastic properties were extracted, organised and analysed through a design of experiments for the subsequent output fitting using the response surface methodology.This research was funded by: INVESTUN/22/BU/0003 // BU-002-P20 // MU-21-UP2021-030

Revista de Vertebrados de la Estación Biológica de Doñana

Datos sobre la fauna de anfibios del Bajo GuadalquivirDiet of the Black Vulture (Aegypius monachus) in the Iberian PeninsulaBiología de reproducción de una pareja de Hieraetus fasciatus en España central.Sobre la migraclon de la focha común (Fulica atra) en el Mediterráneo Occidental en base a la información de la Estación Biológica de laTour du Valat (Camargue, Francia)Problemática y medidas de conservación de la Foca fraile (Monachus monachus, Hermann 1779) en el Sahara OccidentaNuevas citas de sifonápteros parásitos de mamíferos en España.Contribución al estudio de Lacerta monticola en la Sierra de Gredos (Avila. España)A melanistic Spanish smooth snake (Coranella a. austriaca)Nueva localidad para Vipera b. berus en el. Norte de EspañaSegunda cita en España de Porphyrula alleni (Thomson, 1842)Peer reviewe

Vivienda Social y Cooperativismo: Acercamiento de una Propuesta de Vivienda Alternativa.

En el presente trabajo se aborda la producción social de la vivienda, así como el cooperativismo como una forma de esta misma producción. Una vez que en México, el 40% de la población vive bajo la línea de pobreza, en este sentido una de las necesidades es la falta o la calidad de la vivienda para este sector de la población, por lo que en el desarrollo de este trabajo se aborda lo que es el cooperativismo, mencionando algunas características y ejemplos de Uruguay como uno de los países más representativos en este tipo de producción de vivienda, también se abordan dos de los ejemplos más representativos de producción de vivienda por cooperativismo en México y se concluye con una propuesta de vivienda y de la utilización de los Bloques de Tierra Comprimida (BTC) para la producción de vivienda enfocada a este sector. Este trabajo es parte de la investigación financiada por Programa para el desarrollo Profesional Docente (PRODEP). Ha sido construido un prototipo de vivienda con BTC como parte de este, con el objetivo de evaluar su viabilidad de uso

Bienvenidos al Norte: Explotación de la nueva emigración española en el corazón logístico de Europa

Este estudio es la continuación del realizado por miembros de este equipo en el año 2017 y que la Fundación 1º de Mayo publicó en su colección de Estudios1. A raíz de aquella primera publicación, basada en el trabajo de campo realizado en Holanda en febrero del mismo año, fueron numerosas y diversas las reacciones suscitadas por parte de administraciones, medios de comunicación, empresas y trabajadores. Este interés y las nuevas informaciones que íbamos recogiendo en ese intercambio nos llevaron a plantear un proyecto de investigación de mayor envergadura y con un equipo más amplio que constituye la base para la publicación de este segundo estudio2. En esta nueva publicación, analizamos las condiciones de vida y trabajo reales de las y los nuevos emigrantes españoles en Europa central, pero aportamos también datos y reflexiones para comprender los desequilibrios territoriales del modelo productivo europeo que se ha perfilado a partir de los años noventa. Es decir, el nuevo modelo que despunta tras la deslocalización de parte del tejido industrial radicado en los países del sur a nuevos países emergentes comunitarios y extracomunitarios, y que se visibiliza con mucha mayor claridad a partir de la crisis económica de 2007

Role of biological and non biological factors in congestive heart failure mortality: PREDICE-SCORE: A clinical prediction rule

Background: Congestive heart failure (HF) is a chronic, frequent and disabling condition but with a modifiable course and a large potential for improving. The aim of this project was to develop a clinical prediction model of biological and non biological factors in patients with first diagnosis of HF that facilitates the risk-stratification and decision-making process at the point of care. Methods and Results: Historical cohort analysis of 600 patients attended at three tertiary hospitals and diagnosed of a first episode of HF according Framingham criteria. There were followed 1 year. We analyzed sociodemographic, clinical and laboratory data with potential prognostic value. The modelling process concluded into a logistic regression multivariable analysis and a predictive rule: PREDICE SCORE. Age, dependency for daily basic activities, creatinine clearance, sodium levels at admission and systolic dysfunction diagnosis (HF with left ventricular ejection fraction < 40%) were the selected variables. The model showed a c-statistic of 0.763. PREDICE Score, has range of 22 points to stratifications of 1-year mortality. Conclusions: The follow-up of 600 patients hospitalized by a first episode of congestive HF, allowed us to obtain a predictive 1 year mortality model from the combination of demographic data, routine biochemistry and easy handling social and functional variables at the point of care. The variables included were non-invasive, undemanding to collect, and widely available. It allows for risk stratification and therapeutical targeting and may help in the clinical decisions process in a sustainable way

Evaluación de las propiedades de tracción mediante ensayos Small Punch en la zona afectada por los cortes térmicos

Los sistemas de corte térmico provocan una alteración de la zona de material anexa a los bordes de corte, pudiendo así afectar a su comportamiento en servicio. Este artículo pretende aplicar la técnica Small Punch para comparar las propiedades a tracción en el material base y en la Zona Afectada Térmicamente (ZAT) generada por los distintos procesos de corte. El material seleccionado es un acero estructural S460M y se consideran tres métodos de corte térmico con gran trascendencia en ingeniería (oxicorte, corte por plasma y corte por láser). En los bordes de corte resultantes tras cada uno de estos tres procedimientos se ha obtenido la microestructura, se han realizado perfiles de dureza y se han determinado las propiedades de tracción mediante probetas Small Punch. Se ha observado una modificación significativa de las propiedades en la ZAT respecto de las obtenidas en el material base y una variación de las mismas en función de la técnica de corte seleccionada.Thermal cutting processes cause variations in the material next to cutting edges, which may affect its subsequent inservice behaviour. The aim of this paper is to apply the Small Punch technique in order to compare the tensile properties of the base material and the Heat Affected Zone (HAZ) generated by different cutting processes. S460M structural steel has been chosen for this purpose, analysing three different thermal cutting methods of great influence in engineering (oxy-fuel, plasma and laser cutting). Microstructure, hardness profiles and tensile properties by means of Small Punch specimens have been obtained at the resulting cutting edges after the employment of each of these three processes. As a result, a significant deviation of the HAZ properties from the ones obtained for the base material has been observed, as well as an influence of the applied cutting method on the alteration of these properties

Ebola Preparedness and Risk in Latin America

Until today, February 22, 2016, no confirmed Ebola cases have been diagnosed in Americas (except USA, four cases with one death). Confusion, lack of knowledge, and fear have led to quickly misclassify cases as suspected, when in fact most of them are false alarms. Nevertheless, European governments summoned to mobilize resources to attend the Ebola outbreak in West Africa. And also Latin American governments should contribute to halt this humanitarian crisis and to be prepared for the potential arrival of this deadly virus in the Caribbean, Central, and South American mainland. In this chapter, we described the experience of preparedness as well as risk assessment done in Latin America regarding the threat of Ebola for the region