Search

La enfermedad de Kimura se debe sospechar ante masas o nódulos linfoides en cabeza y cuello, con afectación del tejido celular subcutáneo y linfadenopatías regionales, con poca inflamación y pocos síntomas sistémicos, habitualmente acompañadas de eosinofilia periférica y elevación de IgE sérica. Presenta buen pronóstico incluso sin tratamiento, aunque con tendencia a la recidiva. Se presenta el caso de un varón caucásico de 66 años con una masa laterocervical de rápida aparición cuyo diagnóstico final se realizó con la biopsia, en la que se encontraron hallazgos mixtos con hiperplasia angiolinfoide con eosinofilia (HALE), que antes se pensaba que era la misma entidad.

In powder bed fusion laser beam (PBF-LB), powder reusability remains key to keeping cost-effectivity as well as sustainability. In this study, highly sensitive Ti6Al4V ELI powder typically used for medical and aerospace applications is studied. Powder properties of new and reused powders after 10 build cycles subjected to variations such as morphology, particle size distribution (PSD), chemical composition and flowability were analysed. The flow rate using Carney flowmeter increased from 6.8 s to 12 s. Oxygen content slightly increased from 0.11% to 0.12%. The dimensional deviations are measured in six builds of eight samples spread through the build plate. The density of the cubes does not show relevant differences in density (from 99.6% to 99.9%), only the last batch exhibits slightly lower density than the previous builds. Studied properties for the powder and builds are maintained throughout the experiment, demonstrating repeatability of industrial production of metal parts.

The high-energy milling is one of the most extended techniques to produce Oxide dispersion strengthened (ODS) powder steels for nuclear applications. The consequences of the high energy mill process on the final powders can be measured by means of deformation level, size, morphology and alloying degree. In this work, an ODS ferritic steel, Fe-14Cr-5Al-3W-0.4Ti-0.25Y2O3-0.6Zr, was fabricated using two different mechanical alloying (MA) conditions (Mstd and Mact) and subsequently consolidated by Spark Plasma Sintering (SPS). Milling conditions were set to evidence the effectivity of milling by changing the revolutions per minute (rpm) and dwell milling time. Differences on the particle size distribution as well as on the stored plastic deformation were observed, determining the consolidation ability of the material and the achieved microstructure. Since recrystallization depends on the plastic deformation degree, the composition of each particle and the promoted oxide dispersion, a dual grain size distribution was attained after SPS consolidation. Mact showed the highest areas of ultrafine regions when the material is consolidated at 1100 degrees C. Microhardness and small punch tests were used to evaluate the material under room temperature and up to 500 degrees C. The produced materials have attained remarkable mechanical properties under high temperature conditions. Authors want to acknowledge Ferro-Ness project and Ferro- Genesys project funded by MINECO under National I + D + I program MAT2016-80875-C3-3-R and MAT2013-47460-C5-5-P.

En este artículo pretendemos exponer al lector como hemos realizado el manejo de la patología mamaria por parte de la Sección de Radiología durante la pandemia de COVID-19 en un hospital de alta incidencia, como ha sido el “Complejo Hospitalario Universtiario de Albacete”, donde desarrollamos dicha actividad. Para ello, hemos revisado las principales guías de actuación propuestas por diferentes sociedades, haciendo una comparativa con el manejo que hemos realizado por parte de nuestro servicio y viendo si eran todas aplicables y óptimas o si nos hemos visto en la necesidad de modificar algunas de ellas en beneficio de las pacientes, debido tanto a la alta incidencia de patología mamaria no demorable como a la de COVID-19 en nuestra ciudad, siendo nuestro objetivo evitar al máximo el retraso diagnóstico de patología mamaria y sobre todo de cáncer de mama, así como evitar los contagios tanto del personal sanitario como de las pacientes.

BackgroundA strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association.MethodsMarkers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses.ResultWe found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5).ConclusionsThe results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient.

Long noncoding RNAs (lncRNAs) play key roles in cell processes and are good candidates for cancer risk prediction. Few studies have investigated the association between individual genotypes and lncRNA expression. Here we integrate three separate datasets with information on lncRNA expression only, both lncRNA expression and genotype, and genotype information only to identify circulating lncRNAs associated with the risk of gallbladder cancer (GBC) using robust linear and logistic regression techniques. In the first dataset, we preselect lncRNAs based on expression changes along the sequence “gallstones → dysplasia → GBC”. In the second dataset, we validate associations between genetic variants and serum expression levels of the preselected lncRNAs (cis-lncRNA-eQTLs) and build lncRNA expression prediction models. In the third dataset, we predict serum lncRNA expression based on individual genotypes and assess the association between genotype-based expression and GBC risk. AC084082.3 and LINC00662 showed increasing expression levels (p-value = 0.009), while C22orf34 expression decreased in the sequence from gallstones to GBC (p-value = 0.04). We identified and validated two cis-LINC00662-eQTLs (r2 = 0.26) and three cis-C22orf34-eQTLs (r2 = 0.24). Only LINC00662 showed a genotyped-based serum expression associated with GBC risk (OR = 1.25 per log2 expression unit, 95% CI 1.04–1.52, p-value = 0.02). Our results suggest that preselection of lncRNAs based on tissue samples and exploitation of cis-lncRNA-eQTLs may facilitate the identification of circulating noncoding RNAs linked to cancer risk.

In a selective laser melting process, it is common to reuse the powder in consecutive cycles of the route because it is more sustainable and cost effective. However, it is unknown whether reusing the material has an influence on the process. In this paper, Inconel 718, Ti6Al4V, AlSi10Mg and Scalmalloy are characterized to determine the impact of reusing powders on the additive manufacturing (AM) process under an argon high-purity atmosphere. Virgin powders were taken from the suppliers and compared to powders that had been used in the process for a long period of time with periodic ‘rejuvenation’. A well-structured characterization procedure, combining many existing techniques, is proposed, determining changes in the morphology, composition (chemical and microstructure) and flowability. Clear differences between the virgin and used state are revealed by the characterizations; AlSi10Mg, appears to be the most sensitive to reuse with changes in particle size distribution and morphology, and with an increase in the oxygen content. The main contribution of this paper is providing insight into the effects of reuse for four commonly used AM powders, by means of a simple but well-structured method that links the particle feature characterization process to the flowability of metal AM powders. The provided insights enable enhanced decision-making on recycling and reuse of powder for specific AM processes. This research has been supported by the Netherlands Organization for Scientific Research under project number 438-13-207, named SINTAS. The authors are grateful to the Netherlands Aerospace Centre, Additive Industries and the colleagues from Madrid Carlos III, especially Eric Macia and Enrique Herraiz for assisting in the experimental work.

One of the attractive characteristics of high entropy alloys (HEAs) is the ability to tailor their composition to obtain specific microstructures and properties by adjusting the stoichiometry to obtain a body-centered cubic (BCC) or face-centered cubic (FCC) structure. Thus, in this work, the target composition of an alloy of the FeCrCoNi family has been modified by adjusting the Al/Cu ratio in order to obtain a BCC crystalline structure. However, processing conditions always play a key role in the final microstructure and, therefore, in this work, the microstructure evolution of FeCrCoNiAl1.8Cu0.5 HEA sintered by different powder metallurgy (PM) techniques has been investigated. The techniques used range from the conventional PM sintering route, that uses high heating rates and sintering times, going through a fast sintering technique such as spark plasma sintering (SPS) to the novel and promising ultrafast sintering technique electrical resistance sintering (ERS). Results show that the increase in the processing time favours the separation of phases and the segregation of elements, which is reflected in a substantial change in the hardness of the alloy. In conclusion, the ERS technique is presented as a very promising consolidation technique for HEA. The authors gratefully acknowledge the financial support of MAT4.0-CM project funded by Madrid region under programme S2018/NMT-4381. J. Cornide also acknowledges funding from the Spanish Ministry of Science and Innovation (IJCI-2017-31348).

La meningoangiomatosis es una lesión intracraneal benigna y poco frecuente, que afecta fundamentalmente a las leptomeninges y a la corteza cerebral subyacente, siendo más frecuente en niños y adultos jóvenes. Aunque la mayoría de casos se presentan de forma aislada, se ha descrito su asociación con síndromes como la neurofibromatosis tipo 2, estos últimos más frecuentemente asintomáticos y con buena respuesta farmacológica; sin embargo, las presentaciones esporádicas presentan un amplio espectro clínico, abarcando desde cefaleas crónicas hasta crisis convulsivas refractarias, llegando incluso a asociarse a lesiones intracraneales como los meningiomas. En este artículo presentamos nuestra experiencia con una paciente joven que debutó con un episodio de crisis epiléptica focal motora con evolución tónico-clónica generalizada y buena respuesta al tratamiento antiepiléptico. Dada la alta inespecificidad asociada a esta patología, tanto clínica como radiológica, nuestro objetivo es sintetizar los hallazgos radiológicos que nos permiten el planteamiento diagnóstico de esta entidad en pacientes clínicamente compatibles.

The structure of FeCoNiCrAl1.8Cu0.5 high-entropy alloys (HEA) obtained by two different routes has been studied. The selection of the composition has followed the Hume–Rothery approach in terms of number of itinerant electrons (e/a) and average atomic radius to control the formation of specific phases. The alloys were obtained either from a mixture of elemental powders or from gas-atomised powders, being consolidated in both cases by uniaxial pressing and vacuum sintering at temperatures of 1200 °C and 1300 °C. The characterization performed in the sintered samples from both types of powder includes scanning electron microscopy, X-ray diffraction, differential thermal analysis, and density measurements. It was found that the powder production techniques give similar phases content. However, the sintering at 1300 °C destroys the achieved phase stability of the samples. The phases identified by all techniques and confirmed by Thermo-Calc calculations are the following: a major Co-Ni-Al-rich (P1) BCC phase, which stays stable after 1300 °C sintering and homogenising TT treatments, a complex Cr-Fe-rich (P2) B2 type phase, which transforms into a sigma phase after the 1300 °C sintering and homogenising TT treatments, and a very minor Al-Cu-rich (P3) FCC phase, which also transforms into Domain II and Domain III phases during the heating at 1300 °C and homogenising TT treatments.

ResumenEn este artículo presentamos una investigación enmarcada en el Enfoque Cognitivo en Educación Matemática y la hemos desarrollado con estudiantes del primer año de la formación de profesores de matemática en una institución argentina. Inicialmente identificamos una problemática docente que podemos sintetizar como la falta de comprensión de algunos objetos matemáticos que se consideran básicos y base para la construcción de otros de mayor complejidad. A partir de esta inquietud, planteamos un problema de investigación que asume la teoría de las representaciones semióticas de Raymond Duval como marco teórico. El objetivo general fue adquirir conocimiento respecto de la aprehensión conceptual de estudiantes respecto del objeto matemático inecuaciones. Específicamente, nos propusimos describir los registros de representación semiótica que estudiantes de primer año ponen en juego al resolver inecuaciones y al expresar sus conjuntos solución y además describir el grado de aprehensión conceptual alcanzado luego de la enseñanza recibida. Diseñamos, fundamentamos y aplicamos un test para recabar datos y propusimos un análisis en dos dimensiones. Una de ellas nos permitió reconocer los registros utilizados en la resolución de cada uno de los ejercicios mientras que, la otra, nos permitió valorar la aprehensión conceptual alcanzada. Asimismo, el análisis por estudiante nos permitió advertir que varios de ellos se desempeñan, ante las resoluciones de inecuaciones, de maneras semejantes. Esos rasgos comunes fueron plasmados en la construcción de una rúbrica que deja de manifiesto tipos de desempeño que realizan estudiantes que han logrado la aprehensión conceptual en distintas etapas de desarrollo. Finalmente hemos retomado la problemática docente que originó la investigación y dejamos una serie de consideraciones para la enseñanza de las inecuaciones que resultarían clave para favorecer su comprensión.Palabras clave: Aprehensión Conceptual de Inecuaciones. Teoría Semiótica. Inecuaciones. Registros de Representación Semiótica.Um estudo sobre a apreensão conceitual das inequaçõesResumoNeste artigo, apresentamos uma pesquisa enquadrada na Abordagem Cognitiva em Educação Matemática e a desenvolvemos com alunos do primeiro ano de formação de professores de matemática em uma instituição argentina. Inicialmente, identificamos um problema de ensino que podemos sintetizar como a falta de entendimento de alguns objetos matemáticos considerados básicos e a base para a construção de outros de maior complexidade. Com base nessa preocupação, colocamos um problema de pesquisa que assume como referencial teórico a teoria das representações semióticas de Raymond Duval. O objetivo geral foi adquirir conhecimentos sobre a apreensão conceitual dos alunos sobre as desigualdades matemáticas dos objetos. Especificamente, propusemos descrever os registros de representação semiótica que os alunos do primeiro ano colocam em jogo ao resolver desigualdades e expressar seus conjuntos de soluções, além de descrever o grau de apreensão conceitual alcançada após o ensino recebido. Projetamos, suportamos e aplicamos um teste para coletar dados e propusemos uma análise bidimensional. Um deles nos permitiu reconhecer os registros utilizados na resolução de cada um dos exercícios, enquanto o outro nos permitiu avaliar a apreensão conceitual alcançada. Da mesma forma, a análise por aluno permitiu perceber que vários deles realizam, de maneira semelhante, a resolução de desigualdades. Essas características comuns foram refletidas na construção de uma rubrica que revela tipos de desempenho realizados por estudantes que alcançaram apreensão conceitual em diferentes estágios de desenvolvimento.Finalmente, voltamos aos problemas de ensino que deram origem à pesquisa e deixamos uma série de considerações para o ensino de desigualdades que seriam fundamentais para favorecer sua compreensão.Palavras Chave: Apreensão Conceitual das inequações. Teoria semiótica. Inequações. Registros de Representação Semiótica.A study on the conceptual apprehension of inequalitiesAbstractIn this article we present a research framed in the Cognitive approach in Mathematical Education and we worked with students of the first year of the training of mathematics teachers in an argentine institution. Initially, we identified a teaching problem that we can synthesize as the lack of understanding of some mathematical objects that are considered basic and the basis for the construction of others of greater complexity. Based on this concern, we pose a research problem that assumes Raymond Duval's theory of semiotic representations as a theoretical framework. The general objective was to acquire knowledge regarding the conceptual apprehension of students regarding the mathematical object inequalities. Specifically, we pretend to describe the registers of semiotic representation that first-year students use when solving inequalities and expressing their solution sets, and also describing the degree of conceptual apprehension achieved after the teaching received. We designed, supported and applied a test to collect data and proposed a two-dimensional analysis. One of these dimensions allowed us to recognize the semiotic registers used in solving each of the exercises, while the other allowed us to assess the conceptual apprehension achieved by the students. Likewise, the analysis per student allowed us to notice that several of them perform, in the face of the resolution of inequalities, in similar ways. These common features were reflected in the construction of a rubric that reveals types of performance carried out by students who have achieved conceptual apprehension at different stages of development.Finally, we have returned to the teaching problem that originated the research and we leave a series of considerations for teaching inequalities that would be important to be considered for its understanding.Keywords: Conceptual Apprehension of Inequalities. Semiotic Theory. Inequalities. Registers of Semiotic Representation.

Resumen El objetivo del presente artículo derivado de investigación es develar las creencias sobre el proceso de enseñanza y aprendizaje de la habilidad de comprensión lectora que poseen estudiantes de Pedagogía en inglés de una universidad chilena. Se siguió una metodología cualitativa de investigación, empleando un estudio de caso. Los participantes fueron 20 futuros docentes, que estaban cursando su segundo año de formación. Se recogió información a través de una entrevista semiestructurada. Los datos se analizaron utilizando el software Atlas.Ti. Los resultados plantean que los participantes poseen creencias sobre esta habilidad basadas en las formas de procesamiento ascendente y descendente de la información. Al respecto, se señala que los futuros maestros requieren configurar una visión sobre la comprensión lectora desde una perspectiva estratégica. En este contexto, se sugiere que las instituciones formadoras de profesores de inglés los incentiven a realizar prácticas metacognitivas para transformar sus creencias tradicionales. Abstract The objective of the present article derived from research is to unveil the beliefs about the teaching and learning process of the reading comprehension skill that students of Pedagogy in English possess at a Chilean university. The authors followed a qualitative research methodology through a case study. The participants were 20 future teachers, who were in their second year of education. The authors conducted a semi-structured interview and analyzed the participants' answers using the Atlas. Ti software. The findings suggest that the participants hold beliefs concerning reading skills in English which are based on both bottom-up and top-down ways of processing information. In this respect, the authors state that future teachers need to build up a new look at reading comprehension from a strategic approach. In this context, it is suggested that English teacher training institutions encourage them to carry out metacognitive practices to transform their traditional beliefs. Resumo O objetivo do presente estudo é revelar as crenças sobre o processo de ensino e aprendizagem das habilidades de compreensão de leitura que têm alunos de Pedagogia em inglês de uma universidade chilena. A metodologia de pesquisa qualitativa foi considerada, utilizando um estudo de caso. Os participantes foram 20 futuros professores, estando em seu segundo ano de formação. As informações foram coletadas por meio de uma entrevista semiestruturada. Os dados foram analisados utilizando o software Atlas.Ti. Os resultados sugerem que os participantes têm crenças sobre essa habilidade com base nas formas de processamento de informações ascendente e descendente. Sugere-se que as instituições que treinam professores de inglês os incentivem a realizar práticas metacognitivas para transformar suas crenças tradicionais.

High entropy alloys have attracted much interest over the last 16 years due to their promising an unusual properties in different fields that offer many new possible application. Additionally, additive manufacturing has drawn attention due to its versatility and flexibility ahead of a new material challenge, being a suitable technology for the development of metallic materials. Moreover, high entropy alloys have demonstrated that many gaps exist in the literature on its physical metallurgy, and in this sense, additive manufacturing could be a feasible technology for solving many of these challenges. In this review paper the newest literature on this topic is condensed into three different aspects: the different additive manufacturing technologies employed to process high entropy alloys, the influence of the processing conditions and composition on the expected structure and microstructure and information about the mechanical and corrosion behavior of these alloys.

Título de la versión aceptada del artículo: Formation of a γ/γ' microstructure in Co-based superalloys produced by a powder metallurgy route A Co-based superalloy, Co-9Al-9W (at%), was processed by mechanical alloying by high-energy milling of elemental powders and consolidated by field assisted hot pressing (FAHP). The milled powder particles mainly consist of undissolved bcc-W as well as WC and an Al and W rich fcc-γ Co solid solution. After consolidation and heat treatment a fine grained microstructure with a high fraction of carbides and a γ/γ′ microstructure was obtained. The compressive yield strength at room temperature was found to be 45% higher than that of previously reported results for Co-based superalloys. A similar level of strength was found at 700 °C. These extraordinary properties can be explained due to the multitude of hardening mechanisms that sintered Co-based superalloys possess: γ′ precipitation, carbide formation and the ultra-fine γ-grain size promoted by the fast consolidation technique. This work has been developed within the international grant DAAD given by the German Academic Exchange Service. PilotManu (European Union, 7th Framework Programme NMP3-SE-2013-604344) funded by EU has supported as well the development. The authors acknowledge also funding by the Deutsche Forschungsgemeinschaft (DFG) of the Collaborative Research Center SFB/TR 103: “From Atoms to Turbine Blades – A Scientific Approach for Developing the Next Generation of Single Crystal Superalloys”. Publicado

Brazing can be considered as an attractive method for joining sintered steel components since it can be integrated into the sintering process. The behavior and quality of the joint rely on the braze filler design. Among others, the interaction between the base material and the filler depends on the brazing temperature, wettability, infiltration ability, holding time, and sintering atmosphere. The use of this joining technique in components based on Fe Cu C is very common, and in this case the presence of a second liquid phase during sintering can limit the response of braze fillers. In this study, with the aim of analyzing the effect of the base steel composition, a Ni Cu-based brazing will be used together with different Fe-base substrates for sinter-brazing tests: iron is considered as the reference, Fe C to assess the carbon addition effect, and finally Fe C Cu substrate tries to explain the interaction between the two liquid phases (the molten brazing alloy and the Cu transient liquid phase). Characterization of the final joint is supported with SEM and LOM microscopy, and EDS is used for determining the distribution of the alloying elements. Moreover, liquid phase features such as infiltration capacity and diffusion are evaluated by using image analysis. On the other hand, the study is completed with wetting evaluation of the brazing alloy.