Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution

[EN] The tribo-electrochemical behavior of AISI 316L has been investigated under tribocorrosion conditions in a 3% NaCl solution and the material damage evolution with time has been analyzed. A numerical contact model based on a Boundary Element Method (BEM) has been developed in order to determine the contact pressure distribution and to quantify the worn material as a function of time. The time dependence of the tribological behavior of the material has been described. At the initial state, the high contact pressures generate a material flow causing an increase in the worn area. After around 300 cycles, the Archard wear model linearly describes the wear evolution with time. The proposed model describes the evolution with time of the wear profiles of the tested material and takes into account the plastic behavior of the material during the first cycles.This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Ref. MAT2014-53764-C3-3-R and the Generalitat Valenciana under the PROMETEO program Ref. 2016/040.Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2018). Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution. Wear. 394-395:166-175. https://doi.org/10.1016/j.wear.2017.10.015S166175394-39

Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva

[EN] In this paper, the degradation mechanisms of the ceramic and the metal in Titanium/Zirconia pairs for biomedical applications were analyzed. To do that, an experimental set-up with well-controlled mechanical and chemical conditions was used based on a unidirectional ball-on-disk tribometer coupled to a potentiostat. Tribocorrosion tests were carried out in artificial saliva at different applied potentials, this is, different chemical conditions of the surface. Wear damage of the titanium/zirconia pair was influenced by the properties and the behavior of wear debris in the contact. Under passive conditions metallic and oxidized titanium particles (formed by the cyclic removal of the passive film and subsequent repassivation) were smeared and mechanically mixed within the contact forming compacted wear debris through which the loading was carried out. Properties and amount of oxidized titanium lead to low wear at low passive conditions (OCP) and higher wear at high passive conditions. Zirconia did not suffer any damage under all the studied conditions and oxidized titanium was transferred to the ball at anodic applied potentials.Authors would like to acknowledge the Generalitat Valenciana for the financial support under the PROMETEO/2016/040 and GV/2017/042 projects. A. Dalmau acknowledges the Generalitat Valenciana for her contract (APOSTD/2017/051).Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2019). Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva. Wear. 426-427:162-170. https://doi.org/10.1016/j.wear.2018.12.052162170426-42

MR imaging findings in primary spinal cord glioblastoma

Tumors glials; Tumors primaris de medul·la espinal; Glioblastoma de la medul·la espinalTumores gliales; Tumores primarios de la médula espinal; Glioblastoma de la médula espinalGlial tumors; Primary spinal cord tumors; Spinal cord glioblastomaSpinal cord glioblastoma is a rare disease, with an aggressive course and a poor prognosis. We describe magnetic resonance imaging (MRI) findings, in 3 adult cases of biopsy-confirmed glioblastoma. Conventional MRI findings were unclear with regard to the differential diagnosis between this rare tumor and other more common spinal cord lesions, including less aggressive tumors such as ependymoma or pilocytic astrocytoma, abscesses or tumefactive demyelinating lesions. After reasonable exclusion of infectious/inflammatory conditions, a final diagnosis of glioblastoma was established based on histopathological analysis. The cases reported reflect the difficulty of early radiological diagnosis of spinal cord glioblastoma, and indicate the need to perform a biopsy once inflammatory-infectious conditions are excluded with appropriate laboratory tests

MR imaging findings in primary spinal cord glioblastoma

Spinal cord glioblastoma is a rare disease, with an aggressive course and a poor prognosis. We describe magnetic resonance imaging (MRI) findings, in 3 adult cases of biopsy-confirmed glioblastoma. Conventional MRI findings were unclear with regard to the differential diagnosis between this rare tumor and other more common spinal cord lesions, including less aggressive tumors such as ependymoma or pilocytic astrocytoma, abscesses or tumefactive demyelinating lesions. After reasonable exclusion of infectious/inflammatory conditions, a final diagnosis of glioblastoma was established based on histopathological analysis. The cases reported reflect the difficulty of early radiological diagnosis of spinal cord glioblastoma, and indicate the need to perform a biopsy once inflammatory-infectious conditions are excluded with appropriate laboratory tests

Assessment of the use of technical software by the students in the context of mechanical engineering

[EN] In the framework of the European Higher Education area, university teaching has focused in recent years on adapting Master's and Bachelor's degrees to the demands of the professional sector. To do this, the training and development of the generic and specific skills recommended for the incorporation of students into the job market have been priority objectives in the approach to study plans. However, there is no consensus on the methodologies for evaluating these skills, especially regarding how to separate the acquisition and / or improvement of the skills from the specific knowledge and skills of the subjects. Due to the lack of time, teaching staff seek methodologies that do not involve additional tests for the evaluation of competences, which would increase the number of tests to a non-realistic number with the corresponding assessment duties for the professors. In order to make a contribution in this regard, this work presents an approach for evaluating the ability to handle specific software applied to problems in the area of mechanical engineering. This work proposes a methodology for acquiring the required skills and an evaluation system to grade the degree of expertise in the manipulation of the software. In our University, this skill is called the Specific Instrumental Skill, which measures the ability of the students for using the tools in engineering, like, in this case, the use of software to run structural numerical simulations as ANSYS®. The methodology proposed is based on an a priori training. This training is based on 2 hours weekly sessions where the students should solve, in groups of 2 or 3 students, a set of labs with the help of the professor. The students do not need to deliver any report to the professor since the objective of the sessions is the training of the students. Therefore, the pressure over the student is low and the professor avoid to mark a high number of student¿s reports, allowing him to focus only on the learning process of the students and not on the evaluation during the training sessions. These labs increase the difficulty along a number of sessions. The last session consists in an exam in which the students must solve a lab similar to those already solved during the training sessions. This time, each student will work individually without the help of the professor and with a control of the time. Finally, the performance of the methodology is checked by a cross-test for the same students who are part of the group of students of another subject (control subject) where the same tool (ANSYS®) is used. The collected data showed that the students following this methodology acquire the sufficient expertise for handling the software and their skills outperform those of the students of the control subject who did not follow the proposed methodology. As a conclusion, the methodology proposed in this work guarantees a good level of expertise for the students, as shown by the results. Since the results in the final lab exam and the results of the cross-test coincides, the use of the final test exam could be interpreted as a good indicator of the degree of expertise in the use of the software. Additionally, the proposed methodology reduces the work load for the professor as it only requires assessing 1 report per student (instead of several reports for each group of 2 or 3 students in each of the session) while ensuring the authorship of the report.Authors gratefully acknowledge the financial support of the Vicerrectorado de Estudios, Calidad y Acreditación and the Vicerrectorado de Recursos Digitales y Documentación of the Universitat Politècnica de València (project PIME B/19-20/165) and the Instituto de Ciencias de la Educación of the Universitat Politècnica de València (EICE INTEGRAL).Nadal, E.; Rupérez Moreno, MJ.; Giner Navarro, J.; Rovira, A.; Ródenas, JJ.; Martínez Casas, J.; Pedrosa, AM. (2020). Assessment of the use of technical software by the students in the context of mechanical engineering. IATED Academy. 3344-3348. https://doi.org/10.21125/iceri.2020.0756S3344334

Inferring source attribution from a multi-year multi-source dataset of Salmonella in Minnesota

Salmonella enterica is a global health concern because of its widespread association with foodborne illness. Bayesian models have been developed to attribute the burden of human salmonellosis to specific sources with the ultimate objective of prioritizing intervention strategies. Important considerations of source attribution models include the evaluation of the quality of input data, assessment of whether attribution results logically reflect the data trends and identification of patterns within the data that might explain the detailed contribution of different sources to the disease burden. Here, more than 12,000 non-typhoidal Salmonella isolates from human, bovine, porcine, chicken and turkey sources that originated in Minnesota were analysed. A modified Bayesian source attribution model (available in a dedicated R package), accounting for non-sampled sources of infection, attributed 4,672 human cases to sources assessed here. Most (60%) cases were attributed to chicken, although there was a spike in cases attributed to a non-sampled source in the second half of the study period. Molecular epidemiological analysis methods were used to supplement risk modelling, and a visual attribution application was developed to facilitate data exploration and comprehension of the large multiyear data set assessed here. A large amount of within-source diversity and low similarity between sources was observed, and visual exploration of data provided clues into variations driving the attribution modelling results. Results from this pillared approach provided first attribution estimates for Salmonella in Minnesota and offer an understanding of current data gaps as well as key pathogen population features, such as serotype frequency, similarity and diversity across the sources. Results here will be used to inform policy and management strategies ultimately intended to prevent and control Salmonella infection in the state

Mechanisms of glucosa hypersensitivity in ß-cells from normoglycemic, partially pancreatectomized mice

Increased beta-cell sensitivity to glucose precedes the loss of glucose-induced insulin secretion in diabetic animals. Changes at the level of beta-cell glucose sensor have been described in these situations, but it is not clear whether they fully account for the increased insulin secretion. Using a euglycemic-normolipidemic 60% pancreatectomized (60%-Px) mouse model, we have studied the ionic mechanisms responsible for increased beta-cell glucose sensitivity. Two weeks after Px (Px14 group), Px mice maintained normoglycemia with a reduced beta-cell mass (0.88 +/- 0.18 mg) compared with control mice (1.41 +/- 0.21 mg). At this stage, the dose-response curve for glucose-induced insulin release showed a significant displacement to the left (P < 0.001). Islets from the Px14 group showed oscillatory electrical activity and cytosolic Ca2+ ([Ca2+]i) oscillations in response to glucose concentrations of 5.6 mmol/l compared with islets from the control group at 11.1 mmol/l. All the above changes were fully reversible both in vitro (after 48-h culture of islets from the Px14 group) and in vivo (after regeneration of beta-cell mass in islets studied 60 days after Px). No significant differences in the input resistance and ATP inhibition of ATP-sensitive K+ (K(ATP)) channels were found between beta-cells from the Px14 and control groups. The dose-response curve for glucose-induced MTT (C,N-diphenyl-N''-4,5-dimethyl thiazol 2 yl tetrazolium bromide) reduction showed a significant displacement to the left in islets from the Px14 group (P < 0.001). These results indicate that increased glucose sensitivity in terms of insulin secretion and Ca2+ signaling was not due to intrinsic modifications of K(ATP) channel properties, and suggest that the changes are most likely to be found in the glucose metabolism

Comunicación efectiva: un enfoque para distintas asignaturas de la UPV

[EN] To proceed to the accreditation of its degrees, the UPV has developed the concept of competency dimensions in order to group the different academic profiles. This concept allows to homogenize the generic competencies acquired in its degrees, compare and simplify the assessment process to provide adapted tools. In this context, the work presented in this paper is twofold: firstly, it proposes a method for obtaining disaggregated grades for the different competencies in each subject; and, secondly, it develops materials and tools to work with and evaluate different generic competencies associated with the competency dimension of effective communication. Diverse experiences of subjects taught at the UPV are presented in the text, where the approach, materials, and the results achieved in the academic year 2013-2014 are shown. This work was performed under an Educational Improvement and Innovation Project.[ES] Para proceder a la acreditación de sus titulaciones, la UPV ha desarrollado el concepto de dimensiones competenciales con el objeto de agrupar los distintos perfiles formativos. Este concepto permite homogeneizar las competencias genéricas que se adquieren en sus títulos, compararlos y simplificar el proceso de evaluación al poder proporcionar herramientas adaptadas. En este contexto, el trabajo presentado en este artículo tiene un doble objetivo: en primer lugar, propone un procedimiento para obtener una calificación desagregada de las distintas competencias que se trabajan en cada asignatura; y, en segundo lugar, desarrolla materiales e instrumentos para trabajar y evaluar las distintas competencias genéricas asociadas a la dimensión competencial de comunicación efectiva. En el texto se presentan diversas experiencias de asignaturas impartidas en la UPV donde se muestran el planteamiento, los materiales y los resultados conseguidos en el curso académico 2013-2014. Este trabajo se ha realizado bajo un Proyecto de Innovación y Mejora Educativa (PIME).Los autores del trabajo agradecen la ayuda prestada por los técnicos del ICE de la Universitat Politècnica de València (UPV). Este trabajo ha sido financiado por el Vicerrectorado de Estudios, Calidad y Acreditación y la Escuela Técnica Superior de Ingeniería del Diseño (ETSID) a través de la convocatoria de ayudas para PIME 2013-2014 de la UPV, con el proyecto código B15/13Bañón Gomis, AJ.; Clemente-Císcar, M.; Cortés Meseguer, L.; Lajara-Camilleri, N.; Montalva Subirats, JM.; Rovira, A.; Trinidad Tornel, Á.... (2014). Comunicación efectiva: un enfoque para distintas asignaturas de la UPV. Editorial Universitat Politècnica de València. 1191-1205. http://hdl.handle.net/10251/168741S1191120

Experiencias docentes en la UPV en torno a la competencia tranversal "trabajo en equipo y liderazgo"

[Otros] Finished the studies of the first promotions under the EHEA, it is time to evaluate experiences in order to carry out the necessary adjustments. One of the first obstacles that have been pointed out froom its implementation is the way to approach generic skills. Additionally internacional accreditations through certifications such as ABET, highlight the need to work in generic skills in coordination and the necessity of developing tools to assess and to quantify the degree of acquisition of such skills by the students. These evidences are key to certify that the students have reached at least the standards included in the Curriculum of the degree. This paper sets out proposals for the development and assessment of the competency ¿Teamwork and leadership¿, which is the competency dimension nº8 of the Universitat Politécnica de València. Educational experiences included in this text can be easily extrapolated to other courses.[ES] Finalizadas las primeras promociones de estudiantes que han desarrollado sus estudios bajo el Espacio Europeo de Educación Superior (EEES), llega el momento de evaluar las experiencias para poder llevar a cabo los ajustes necesarios. Uno de los primeros escollos que se vienen señalando desde su implantación es la forma de abordar las competencias transversales. Adicionalmente la acreditación internacional a través de certificaciones como ABET (Accreditation Board for Engineering and Technology), pone de manifiesto la necesidad de trabajar de forma coordinada las competencias genéricas y de desarrollar herramientas que permitan evaluar y cuantificar el grado de adquisición de dichas competencias por parte de los estudiantes para certificar la consecución de los niveles mínimos recogidos en la titulación de Grado. Esta comunicación expone propuestas de desarrollo y evaluación de la competencia liderazgo y trabajo en equipo , que constituye la dimensión competencial nº8 de la Universitat Politècnica de València. Se recogen experiencias docentes que por su enfoque generalista pueden ser fácilmente extrapolables a otras titulaciones. El trabajo expuesto forma parte de los resultados obtenidos en el PIME B14/13 de la convocatoria 2013-2014 de la UPV, titulado Desarrollo de metodologías de adquisición y evaluación de la competencia trabajo en equipo y liderazgo .This work is part of the results of the PIME B14/13 of the UPV, entitled "Development of methods for the acquisition and assessment of the competency teamwork and leadership"Bañón Gomis, AJ.; Clemente Císcar, M.; Cortés Meseguer, L.; Lajara-Camilleri, N.; Pérez De Los Cobos Cassinello, M.; Rodrigo Molina, A.; Rovira, A.... (2014). Experiencias docentes en la UPV en torno a la competencia tranversal "trabajo en equipo y liderazgo". Editorial Universitat Politècnica de València. 1-14. http://hdl.handle.net/10251/168626S11

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age