Inverse homogenization using the topological derivative

Purpose: The purpose of this study is to solve the inverse homogenization problem, or so-called material design problem, using the topological derivative concept. Design/methodology/approach : The optimal topology is obtained through a relaxed formulation of the problem by replacing the characteristic function with a continuous design variable, so-called density variable. The constitutive tensor is then parametrized with the density variable through an analytical interpolation scheme that is based on the topological derivative concept. The intermediate values that may appear in the optimal topologies are removed by penalizing the perimeter functional. Findings: The optimization process benefits from the intermediate values that provide the proposed method reaching to solutions that the topological derivative had not been able to find before. In addition, the presented theory opens the path to propose a new framework of research where the topological derivative uses classical optimization algorithms. Originality/value: The proposed methodology allows us to use the topological derivative concept for solving the inverse homogenization problem and to fulfil the optimality conditions of the problem with the use of classical optimization algorithms. The authors solved several material design examples through a projected gradient algorithm to show the advantages of the proposed method.This research was partially supported by Serra Húnter Research Program (Spain), PID-UTN (Research and Development Program of the National Technological University, Argentina) and CONICET (National Council for Scientific and Technical Research, Argentina). The supports of these agencies are gratefully acknowledged.Peer ReviewedPostprint (author's final draft

Topological sensitivity analysis in heterogeneous anisotropic elasticity problem: theoretical and computational aspects

The topological sensitivity analysis for the heterogeneous and anisotropic elasticity problem in two-dimensions is performed in this work. The main result of the paper is an analytical closed-form of the topological derivative for the total potential energy of the problem. This derivative displays the sensitivity of the cost functional (the energy in this case) when a small singular perturbation is introduced in an arbitrary point of the domain. In this case, we consider a small disc with a completely different elastic material. Full mathematical justification for the derived formula, and derivations of precise estimates for the remainders of the topological asymptotic expansion are provided. Finally, the influence of the heterogeneity and anisotropy is shown through some numerical examples of structural topology optimization.Peer ReviewedPostprint (author's final draft

A two-scale failure model for heterogeneous materials: numerical implementation based on the finite element method

This is the accepted version of the following article: Toro, S., Sánchez, P.J., Huespe, A.E., Giusti, S.M., Blanco, P.J. and Feijóo, R.A. (2014), A two-scale failure model for heterogeneous materials: numerical implementation based on the finite element method. Int. J. Numer. Meth. Engng., 97: 313–351. doi: 10.1002/nme.4576, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/nme.4576/abstractIn the first part of this contribution, a brief theoretical revision of the mechanical and variational foundations of a Failure-Oriented Multiscale Formulation (FOMF) devised for modeling failure in heterogeneous materials is described. The proposed model considers two well separated physical length scales, namely: (i) the “macro” scale where nucleation and evolution of a cohesive surface is considered as a medium to characterize the degradation phenomenon occurring at the lower length scale, and (ii) the “micro” scale where some mechanical processes that lead to the material failure are taking place, such as strain localization, damage, shear band formation, etc. These processes are modeled using the concept of Representative Volume Element (RVE). On the macro scale, the traction separation response, characterizing the mechanical behavior of the cohesive interface, is a result of the failure processes simulated in the micro scale. The traction separation response is obtained by a particular homogenization technique applied on specific RVE subdomains. Standard, as well as, Non-Standard boundary conditions are consistently derived in order to preserve “objectivity” of the homogenized response with respect to the micro-cell size. In the second part of the paper, and as an original contribution, the detailed numerical implementation of the two-scale model based on the Finite Element Method is presented. Special attention is devoted to the topics which are distinctive of the FOMF, such as: (i) the finite element technologies adopted in each scale along with their corresponding algorithmic expressions, (ii) the generalized treatment given to the kinematical boundary conditions in the RVE and (iii) how these kinematical restrictions affect the capturing of macroscopic material instability modes and the posterior evolution of failure at the RVE level. Finally, a set of numerical simulations is performed.Peer ReviewedPostprint (author’s final draft

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

I Congresso Ibero-Americano de Bibliotecas Escolares

Actas de la primera edición del I Congreso Iberoamericano de Bibliotecas Escolares, CIBES 2015, organizado por la Universidad Carlos III de Madrid (España), la Universidad Estatal Paulista (Brasil) y el Ayuntamiento de Getafe (España). Celebrado: 21 - 23 de octubre de 2015 en la Universidad Estatal Paulista (Marília) y 26 - 28 de octubre de 2015 en la Universidad Carlos III de Madrid (Getafe)Universidad Carlos III de Madrid (España)Universidad Estatal Paulista (Brasil)Ayuntamiento de Getafe (España)Dimensiones y visiones de la biblioteca escolar en una Educación por competencias: la necesidad de una política estratégica / Miguel Ángel Marzal. -- Getafe ciudad educadora, lectora y escritora: Bibliotecas escolares / Lourdes Muñoz Santiuste. -- Presente y futuro: biblioteca escolar-CREA y proyectos interdisciplinares / Rosa Piquín. -- Cultura en información: un reto esencial de la biblioteca escolar / Mónica Baró. -- Bibliotecas escolares de Galicia: un mundo de oportunidades a favor de la Educación / Cristina Novoa. -- 10 años de la Red de Bibliotecas Escolares de Extremadura (REBEX) / Casildo Macías Pereira. -- Biblioteca Escolar y uso ético de la información para una Cultura de Paz / Ana Barrero Tíscar. -- Dinamización de la Biblioteca Escolar Plumita durante el curso escolar 2014/15 / María Antonia Cano Cañada. -- Experiencia de la creación de una biblioteca escolar / Susana Santos Martín. -- Grupo cooperativo Bibliotecas escolares en Red-Albacete / José Manuel Garrido Argandoña y Eva Leal Scasso. -- La BCREA "Juan Leiva". El fomento de la lectura desde la web social / Andrés Pulido Villar. -- Proceso de implantación de una herramienta de autoevaluación en la red de bibliotecas escolares de Extremadura (REBEX) / Casildo Macías Pereira. -- La biblioteca escolar: abriendo fronteras / Lorena Verónica Cabrera Orellana. -- O programa RBE e a avaliaçao das bibliotecas escolares: melhoria, desenvolvimiento e innovaçao / Elsa Conde. -- Profesional de Biblioteconomía y Documentación: esencial en la plantilla de la escuela / Pilar del Campo Puerta. -- Una mirada activa al proceso educativo desde la biblioteca escolar / María Jesús Fontela Fernández . -- Con otra mirada "La ilustración como vehículo de comunicación y aprendizaje en las bibliotecas escolares" / Pablo Jurado Sánchez-Galán. -- Fingertips. Recriar a biblioteca escolar na sala de aula / Rui Alfonso Mateus. -- Hablemos de libros. Cómo transformar una clase de literatura en una comunidad de interpretación de textos / Francisco César Díaz Rey. -- Inclusión social de familias inmigrantes a través de un programa de aprendizaje de la lengua castellana / Ana Carmen Tolino Fernández-Henarejos. -- O desenvolvimento de atividades de mediação de leitura em biblioteca escolar: o caso da biblioteca da Escola Sesc de Ensino Médio / Vagner Amaro. -- La biblioteca escolar. Proceso de enseñanza-aprendizaje de padres a hijos / Ana Carmen Tolino Fernández- Henarejos. -- Leo con y para los demás / Ismael Fernández Fernández, Ana María Moreno Vicente y Ana Beatriz Vicente Pérez. -- Nanas y arrullo. Poesía a la deriva / Bernardo Fuentes Navarrete y Carlos García-Romeral Pérez. -- Gestión y evaluación de servicios bibliotecarios para personas con dislexia: una biblioteca escolar inclusiva desde una perspectiva internacional / Carmen Jorge García-Reyes. -- Sueños lectores compartidos hechos realidad: la biblioteca escolar del C.E.I.P-S.E.S-A.A “LA PAZ” de Albacete / Ana Rosa Cabañero Tobarra, Juan Manuel Herráez, Eva Leal Scasso, María Marín Sánchez, Ana Belén Medrano Martínez y María José Nortes Ruipérez. -- El programa biblioteca escuela en Civican. La literatura como elemento motivador para la alfabetización informacional / Villar Arellano Yanguas. -- La competencia digital en el diseño curricular: desde la biblioteca al aula / Felicidad Campal García. -- O deselvomimento da pesquisa escolar por meio da competência em informaçao / Luciane de Fátima Cavalcante Beckman y Marta Leandro da Mata. -- Proyecto escolar de investigación documental "Te pillé leyendo" / José Manuel Garrido Argandoña. -- Aprender com a Biblioteca Escolar: formar para as literacias / Paula Correia y Isabel Mendinhos. -- Sucedió en el siglo XX / María Antonia Becerra Montalbán, Ángel Bernabé Muñoz y Sofía Vaz Romero. -- El Club de lectura en la nube / Belén Benito Blázquez y Ana Ordás García. -- Promover a leitura e a escrita na era digital: prácticas nas bibliotecas escolares / María Raquel Ramos. -- A biblioteca escolar e o desafío da interculturalidade: o projeto Ser + cidadao / María da Conceição Tomé. -- Cuando la competencia digital encontró a la alfabetización informacional o Mucho ruido y pocas nueces / Felicidad Campal García. -- Hora de ler, un programa para el fomento de la lectura en contexto educativo / Cristina Novoa. -- Hábitos de lectura para las competencias en información y alfabetización en información en bibliotecas escolares de Puerto Rico / Karen Denise Centeno Casillas. -- Repositorios digitales en las bibliotecas escolares andaluzas: situación, modelos y herramientas para su creación / Dolores Olmos Olmos y Andrés Pulido Villar. -- Trabajando las competencias clave con las aventuras de Mozarito en Extremadura / María Teresa Carballosa González y María Esther Nieto Vidal. -- Análisis de modelos de evaluación de la web de la biblioteca escolar / Raúl Cremades García. -- Emociónate con las historias: El bosque de las emociones e historias con mucho teatro / Esther Luis Pérez y Ana María Peromingo Fernández. -- Biblioteca escolar de innovación y continuación / E. María Guerrero Palacios y Silvia Mora Ramírez. -- Uso de estándares y licencias para la creación y difusión de contenidos en las bibliotecas escolares / José Luis Barreiro Cebey. -- La biblioteca escolar digital móvil / Javier Fernández Delgado. -- Uso de aplicaciones móviles para el desarrollo de la competencia lingüística. Proyecto Hansel App Gretel / Dolores Olmos Olmos. -- A memória e a mediação segundo Vigotski / Leda Maria Araújo, Patricia Celia Santana, Sueli Bortolin y Leticia Gorri Molina. -- Bibliotecas escolares como tema de estudo dos alunos de graduação em blioteconomia do Instituto de Ensino Superior da FUNLEC: estado da arte / Tiago Pereira Nocera y Rodrigo Pereira. -- Ações de mediação da leitura e da informação em bibliotecas escolares: um olhar sobre as bibliotecas dos Colégios de Aplicação / Tatyanne Christina Gonçalves Ferreira Valdez y Alberto Calil Júnior. -- Mediação pedagógica numa biblioteca de escola pública em Londrina / Rovilson José da Silva, Teba Silva Yllana y Sueli Bortolin. -- Utilização de categorias por cores em sistema de biblioteca voltado ao público infanto-juvenil / Liliana Giusti Serra. -- Atividades de ensino dos atos de leitura com crianças em risco social / Adriana Naomi Fukushima da Silva y Dagoberto Buim Arena. -- Biblioteca escolar: espaço de significados entre alunos, professores e bibliotecários / Rodrigo Barbosa Paulo, Marisa Xavier, Helen Castro Casarin y Creuza Barbaroto. -- A Biblioteca Escolar no Contexto da Legislação e do Processo Educativo / Eliane Lourdes da Silva Moro, Francisca Rosaline Leite Mota y Raimundo Martins de Lima. -- O jornal impresso como fonte de informação: a importância da formação de leitores críticos / Mariana Pícaro Cerigatto. -- Bibliotecas escolares no estado do Rio Grande do Sul: a trajetória de realização dos fóruns gaúchos pela melhoria das bibliotecas escolares / Eliane Lourdes da Silva Moro y Lizandra Brasil Estabel. -- O acesso à informação dos usuários surdos na biblioteca escolar / André Luís Onório Coneglian y Mayara Melo Santana. -- Aprendizagem coletiva de bibliotecários e a competência de pesquisa dos docentes: o caso do Instituto Federal do Espírito Santo / Maristela Almeida Mercandeli Rodrigues y Beatriz Quiroz Villardi. -- Biblioteca escolar: atores, parâmetros e competências / Mavi Galante Mancera Dall´Acqua Carvalho y Claudio Marcondes de Castro Filho. -- Estratégias de aprendizagem de escrita no Ensino Fundamental II / Érika Christina Kohle. -- Bebês e livros: leitura nas bebetecas. Kenia Adriana de Aquino Modesto Silva, Juliane Francischeti Martins Motoyama y Renata Junqueira de Souza. -- Práticas alternativas para organização de acervos nos espaços de leitura em ambientes escolares / Luciana Souza Gracioso, Ariovaldo Alves, Débora Nascimento, Suelen Redondo, Tainara Torika Kiri de Castro, Elizabete Angelon y Eduardo Barbosa. -- Reflexões sobre a modelagem e criação de uma Rede Virtual de Leitores para Bibliotecas Escolares / Carla Floriana Martins y Raoni Guerra Rajão. -- Biblioteca escolar: espaço de formação leitora? / Silvana Ferreira de Souza Balsan y Renata Junqueira de Souza. -- “Se a Biblioteca Escolar é minha mãe, o Google é meu pai”: representações da relação entre Biblioteca Escolar e Google no imaginário de alunos do ensino técnico / Adriana Bogliolo Sirihal-Duarte, Maria L. Amorim Antunes y Raquel Miranda Vilela Paiva. -- Desafios e propostas para a universalização das bibliotecas escolares no Brasil e na Espanha / Rodrigo Pereira, Daniela Spudeit y Fernanda de Sales. -- Bibliotecário educador: possibilidades de atuação no contexto da biblioteca escolar / André Carlos da Silva, Valéria Martin Valls y Mariana de Paula Silva. -- Uma ONG para Bibliotecas Escolares : estratégia para ampliar a igualdade e capacidade de acesso e uso da informação e educação escolar de qualidade / Suelen Camilo Ferreira y Luciana de Souza Gracioso. -- O aluno com deficência: o papel do bibliotecário na disponibilidade de recursos acessíveis na biblioteca escolar / Adriano de Sales Coelho, Rosilene de Melo Oliveira y Marcos Pastana Santos. -- Biblioteca digital virtual e o uso do tablete: uma possibilidade de construção de novas práticas de leitura na escola / Barbara Cibelli da Silva Monteagudo y Dagoberto Buim Arena. -- A importância da biblioteca na educação de crianças de 0 a 3 anos / Yngrid Karolline Mendonça Costa y Cyntia Graziella Guizelim Simões Girotto. -- Comportamento Informacional de adolescentes: a relação com bibliotecas e escolas / Nelson Sebastian Silva-Jerez y Helen de Castro S. Casarin

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Design of bi-metallic devices based on the topological derivative concept

In this work the topological derivative concept is applied in the context of topology design of thermo-mechanical devices, where the linear elasticity system (modeled by the Navier equation) is coupled with the steady-state heat conduction problem (modeled by the Laplace equation). The mechanical coupling term comes out from the thermal stress induced by the temperature field. We consider the topology design of bi-metallic devices. The idea is to maximize the displacement in a given direction defined on the boundary of the thermo-elastic body with respect to a bi-metallic material distribution. The topological derivative is obtained by considering the nucleation of a small circular inclusion with different thermal expansion coefficients. A level-set domain representation method is used, together with the derived topological sensitivity formula, to devise a topology design algorithm. Finally, some numerical experiments regarding the conceptual design of thermo-mechanical devices are presented.Fil: Giusti, Sebastian Miguel. Universidad Tecnológica Nacional. Facultad Regional Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Novotny, A. A.. Laboratorio Nacional de Computacao Cientifica; Brasi