Experimental study on bond performance of GFRP bars in self-compacting steel fiber reinforced concrete

Reinforcing bars made of Glass-Fiber-Reinforced Polymers (GFRP) are more and more common as internal reinforcement of concrete structures and infrastructures. Since the design of GFRP reinforced concrete members is often controlled by serviceability limit state criteria (i.e., deflection or crack width control), an accurate knowledge of the GFRP-concrete bond behavior is needed to formulate sound design equations. Furthermore, bond laws currently available and widely accepted for conventional steel rebars cannot be straightforwardly applied for GFRP ones. Hence, an experimental program consisting of 36 pullout bending tests was carried out to evaluate the bond performance between GFRP bars and steel fiber reinforced self-compacting concrete (SFRSCC) by analyzing the influence of the following parameters: GFRP bar diameter, surface characteristics of the GFRP bars, bond length, and SFRSCC cover thickness. Based on the results obtained in this study, pullout failure was occurred for almost all the specimens. SFRSCC cover thickness and bond length plaid important role on the ultimate value of bond stress of GFRP bars. Moreover, the GFRP bars with ribbed and sand-coated surface treatment showed different interfacial bond behaviors.Fundação para a Ciência e a Tecnologia (FCT

Numerical calibration of bond laws for GFRP bars embedded in steel fiber-reinforced self-compacting concrete

An experimental program was carried out at the Laboratory of Structural Division of the Civil Engineering Department of the University of Minho (LEST-UM) to investigate the bond behaviour of glass fibre reinforced polymer (GFRP) bars embedded in steel fibre reinforced self-compacting concrete (SFRSCC) for the development of an innovative structural system. Thirty-six pull-out-bending tests were executed to assess the influence of the bond length, concrete cover, bar diameter and surface treatment on the bond of GFRP bars embedded in SFRSCC. This paper reports the results of a numerical study aiming to identify an accurate GFRP–SFRSCC bond-slip law. Thus, the above mentioned pullout bending tests were simulated by using a nonlinear finite element (FE) constitutive model available in FEMIX, a FEM based computer program. The bond-slip relationship adopted for modelling the FE interface that simulates the interaction between bar and concrete is the key nonlinear aspect considered in the FE analyses, but the nonlinear behaviour of SFRSCC due to crack initiation and propagation was also simulated. The evaluation of the values of the relevant parameters defining such a bond-slip relationship was executed by fitting the force versus loaded end slip responses recorded in the experimental tests. Finally, correlations are proposed between the parameters identifying the bond-slip relationship and the relevant geometric and mechanical properties of the tested specimens.Fundação para a Ciência e a Tecnologia (FCT

Critical properties of Ising model on Sierpinski fractals. A finite size scaling analysis approach

The present paper focuses on the order-disorder transition of an Ising model on a self-similar lattice. We present a detailed numerical study, based on the Monte Carlo method in conjunction with the finite size scaling method, of the critical properties of the Ising model on some two dimensional deterministic fractal lattices with different Hausdorff dimensions. Those with finite ramification order do not display ordered phases at any finite temperature, whereas the lattices with infinite connectivity show genuine critical behavior. In particular we considered two Sierpinski carpets constructed using different generators and characterized by Hausdorff dimensions d_H=log 8/log 3 = 1.8927.. and d_H=log 12/log 4 = 1.7924.., respectively. The data show in a clear way the existence of an order-disorder transition at finite temperature in both Sierpinski carpets. By performing several Monte Carlo simulations at different temperatures and on lattices of increasing size in conjunction with a finite size scaling analysis, we were able to determine numerically the critical exponents in each case and to provide an estimate of their errors. Finally we considered the hyperscaling relation and found indications that it holds, if one assumes that the relevant dimension in this case is the Hausdorff dimension of the lattice.Comment: 21 pages, 7 figures; a new section has been added with results for a second fractal; there are other minor change

Entanglement of two-mode Gaussian states: characterization and experimental production and manipulation

A powerful theoretical structure has emerged in recent years on the characterization and quantification of entanglement in continuous-variable systems. After reviewing this framework, we will illustrate it with an original set-up based on a type-II OPO with adjustable mode coupling. Experimental results allow a direct verification of many theoretical predictions and provide a sharp insight into the general properties of two-mode Gaussian states and entanglement resource manipulation

Reactividad del sistema bifásico tricloroacetonitrilo-CH2Cl2/H2O2 en la epoxidación del aceite de soja

In this work we report on the epoxidation of soybean oil by the trichloroacetonitrile -CH2Cl2/H2O2 byphasic system. The reaction was carried out at room temperature and, most importantly, in non acid conditions which prevent the opening of the oxirane ring. The epoxidized soybean oil was characterized by infrared, 1H and 13C NMR. A maximum conversion of 81 % was achieved in two hours with 86% of selectivity in epoxy groupsEn el presente trabajo informamos sobre la epoxidación de aceite de soja mediante el sistema bifásico tricloroacetonitrilo-CH2Cl2/H2O2. La reacción fue realizada bajo condiciones de temperatura ambiente y, lo más importante, en condición no ácida, lo que evita la apertura del anillo oxirano. El aceite de soja fue caracterizado por infrarrojo y RMN de 1H and 13C. En dos horas se alcanzó una conversión máxima del 81 % obteniéndose una selectividad del 86 % en grupos epóxido

Klebsiella pneumoniae is able to trigger epithelial-mesenchymal transition process in cultured airway epithelial cells

The ability of some bacterial pathogens to activate Epithelial-Mesenchymal Transition normally is a consequence of the persistence of a local chronic inflammatory response or depends on a direct interaction of the pathogens with the host epithelial cells. In this study we monitored the abilities of the K. pneumoniae to activate the expression of genes related to EMT-like processes and the occurrence of phenotypic changes in airway epithelial cells during the early steps of cell infection. We describe changes in the production of intracellular reactive oxygen species and increased HIF-1α mRNA expression in cells exposed to K. pneumoniae infection. We also describe the upregulation of a set of transcription factors implicated in the EMT processes, such as Twist, Snail and ZEB, indicating that the morphological changes of epithelial cells already appreciable after few hours from the K. pneumoniae infection are tightly regulated by the activation of transcriptional pathways, driving epithelial cells to EMT. These effects appear to be effectively counteracted by resveratrol, an antioxidant that is able to exert a sustained scavenging of the intracellular ROS. This is the first report indicating that strains of K. pneumoniae may promote EMT-like programs through direct interaction with epithelial cells without the involvement of inflammatory cells

Genetic and epigenetic alterations of cdh1 regulatory regions in hereditary and sporadic gastric cancer

E-cadherin is a key player in gastric cancer (GC) and germline alterations of CDH1, its encoding gene, are responsible for Hereditary Diffuse Gastric Cancer (HDGC) syndrome. This study aimed at elucidating the role of genetic variants and DNA methylation of CDH1 promoter and enhancers in the regulation of gene expression. For this purpose, we analyzed genetic variants of the CDH1 gene through Next-Generation Sequencing (NGS) in a series of GC cell lines (NCI-N87, KATO-III, SNU-1, SNU-5, GK2, AKG, KKP) and the corresponding CDH1 expression levels. By bisulfite genomic sequencing, we analyzed the methylation status of CDH1 regulatory regions in 8 GC cell lines, in a series of 13 sporadic GC tissues and in a group of 20 HDGC CDH1-negative patients and 6 healthy controls. The NGS analysis on CDH1 coding and regulatory regions detected genetic alterations in 3 out of 5 GC cell lines lacking functional E-cadherin. CDH1 regulatory regions showed different methylation patterns in patients and controls, GC cell lines and GC tissues, expressing different E-cadherin levels. Our results showed that alterations in terms of genetic variants and DNA methylation patterns of both promoter and enhancers are associated with CDH1 expression levels and have a role in its regulation.This research and its authors were funded by IRCCS IRST (G.T., C.M., R.D. V.A., M.R., F.R., M.C., S.P., G.M., D.C., P.U.) and by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020–Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT–Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274) (C.S.J., R.B.-M., A.A., C.O.). This work was also financed by the project NORTE-01-0145-FEDER-000029 (CANCER)-supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF)–project POCI-01-0145-FEDER-016390 (CancelStem) and PTDC/BTM-TEC/30164/2017 (3DChroMe), funded by ERDF, POCI and FCT

ESTRESSE PERCEBIDO E TRANSTORNOS NÃO-PSICÓTICOS: UMA CORRELAÇÃO ENTRE OS SINTOMAS EM PROFISSIONAIS DE ENFERMAGEM NA PANDEMIA COVID-19

Stress is defined as a natural and necessary process of the body to react to danger. This adaptive process is always active, causing physical and emotional changes. In order to raise, among nursing professionals, the psychic suffering stemming from the COVID-19 pandemic, this study used the cross-sectional, descriptive, quantitative observational method. The research was carried out in two public hospitals in the city of São Luís/MA, from the application of questionnaires of sociodemographic data, SRQ-20 and Perceived Stress Scale, through the Google Forms platform to the selected group, and for analysis the Software SPSS (version 21) was used in order to obtain descriptive statistics (mean, deviation and frequencies), Pearson r correlation and mean difference tests. The results describe the degree of suffering to which they were exposed during the work exercise, mostly by female nursing professionals, aged between 26 and 36 years, brown, single and Catholic. It was also noticed that these professionals have children, most of them are of higher education, with a workload of 36 h, having only one bond and earning between 1 and 2 salaries, part of the sample presented psychic suffering and stress at work. It was concluded that coping with stressors causing psychic suffering, psychosocial support and active participation of managers from all spheres involved would result in the construction of resilient professionals for the health system.El estrés se define como un proceso natural y necesario del cuerpo para reaccionar ante el peligro. Este proceso adaptativo está siempre activo, causando cambios físicos y emocionales. Con el objetivo de elevar, entre los profesionales de enfermería, el sufrimiento psíquico derivado de la pandemia de COVID-19, este estudio utilizó el método observacional transversal, descriptivo y cuantitativo. La investigación fue realizada en dos hospitales públicos de la ciudad de São Luís/MA, a partir de la aplicación de cuestionarios de datos sociodemográficos, SRQ-20 y Escala de Estrés Percibido, a través de la plataforma Google Forms al grupo seleccionado, y para el análisis se utilizó el Software SPSS (versión 21) para obtener estadística descriptiva (media, desviación y frecuencias), correlación r de Pearson y pruebas de diferencia de medias. Los resultados describen el grado de sufrimiento al que fueron expuestas durante el ejercicio laboral, en su mayoría por mujeres profesionales de enfermería, con edades entre 26 y 36 años, morenas, solteras y católicas. También se notó que estos profesionales tienen hijos, la mayoría de ellos son de educación superior, con una carga de trabajo de 36 h, teniendo un solo vínculo y ganando entre 1 y 2 salarios, parte de la muestra presentó sufrimiento psíquico y estrés en el trabajo. Se concluyó que el enfrentamiento de los factores estresantes que causan sufrimiento psíquico, el apoyo psicosocial y la participación activa de los gestores de todas las esferas involucradas resultarían en la construcción de profesionales resilientes para el sistema de salud.O estresse é definido como um processo natural e necessário do organismo para reagir ao perigo. Esse processo adaptativo está sempre ativo, causando alterações físicas e emocionais. Com objetivo de levantar, dentre os profissionais da enfermagem, os sofrimentos psíquicos advindos em decorrência da pandemia do COVID-19, este estudo se utilizou do método observacional transversal, descritivo, de abordagem quantitativa. A pesquisa foi realizada em dois hospitais da rede pública da cidade de São Luís/MA, a partir da aplicação de questionários de dados sociodemográficos, SRQ-20 e Escala de Estresse Percebido, através da plataforma Google Forms ao grupo selecionado, e para análise se utilizou o software SPSS (versão 21), com o intuito de obter as estatísticas descritivas (média, desvio padrão e frequências), correlação r Pearson e testes de diferença de média. Os resultados descrevem o grau de sofrimento ao qual foram expostos durante o exercício laboral, em sua maioria, por profissionais de enfermagem do sexo feminino, com faixa etária entre 26 e 36 anos, de cor parda, solteiros e católicos. Percebeu-se também que estes profissionais possuem filhos, a maioria é de nível superior, com carga horária de 36h, possuindo apenas um vínculo e ganhando entre 1 e 2 salários, parte da amostra apresentou sofrimento psíquico e estresse no trabalho. Concluiu-se que enfrentamento aos fatores estressores causadores de sofrimento psíquico, o suporte psicossocial e participação ativa dos gestores de todas as esferas envolvidas, resultariam na construção de profissionais resilientes para o sistema de saúde.  O estresse é definido como um processo natural e necessário do organismo para reagir ao perigo. Esse processo adaptativo está sempre ativo, causando alterações físicas e emocionais. Com objetivo de levantar, dentre os profissionais da enfermagem, os sofrimentos psíquicos advindos em decorrência da pandemia do COVID-19, este estudo se utilizou do método observacional transversal, descritivo, de abordagem quantitativa. A pesquisa foi realizada em dois hospitais da rede pública da cidade de São Luís/MA, a partir da aplicação de questionários de dados sociodemográficos, SRQ-20 e Escala de Estresse Percebido, através da plataforma Google Forms ao grupo selecionado, e para análise se utilizou o software SPSS (versão 21), com o intuito de obter as estatísticas descritivas (média, desvio padrão e frequências), correlação r Pearson e testes de diferença de média. Os resultados descrevem o grau de sofrimento ao qual foram expostos durante o exercício laboral, em sua maioria, por profissionais de enfermagem do sexo feminino, com faixa etária entre 26 e 36 anos, de cor parda, solteiros e católicos. Percebeu-se também que estes profissionais possuem filhos, a maioria é de nível superior, com carga horária de 36h, possuindo apenas um vínculo e ganhando entre 1 e 2 salários, parte da amostra apresentou sofrimento psíquico e estresse no trabalho. Concluiu-se que enfrentamento aos fatores estressores causadores de sofrimento psíquico, o suporte psicossocial e participação ativa dos gestores de todas as esferas envolvidas, resultariam na construção de profissionais resilientes para o sistema de saúde.