Early-age shrinkage and bond of LC-TRM strengthening in rammed earth

The wide dissemination of earth-based structures as contemporary, vernacular or heritage constructions in re-gions with important seismic hazard demands the design of solutions that improve the typical low structural performance resulting from intrinsic material limitations. Only in this way, it is possible to promote a comprehensive seismic protection of this heritage and of the life of their inhabitants. One relevant and innovative solution proposed recently to address this problem consists in the strengthening with low-cost textile meshes embedded in a mortar matrix (LC-TRM). The purpose of this solution is similar to that of fibre reinforced polymers (FRP) systems used in masonry structures, where it works as an externally bonded reinforcement. Nevertheless, LC-TRM is addressed to elements constituted by materials with low mechanical properties, such as rammed earth and adobe. The further development of this strengthening solution demands comprehending with detail the interaction between the substrate and the matrix, where the shrinkage behaviour is relevant for the success of the system. The capacity of non-destructive tests based on digital image correlation (DIC) suggest the possibility of using this technique to monitor mortar shrinkage in LC-TRM strengthened rammed earth walls. On this regard, an experimental program was conducted and provided many important conclusions, among which are that DIC provides an adequate monitoring of the shrinkage behaviour of LC-TRM strengthened systems and that the strengthening mesh is a key element for controlling shrinkage development. Additionally, the interaction between the substrate and the LC-TRM system was characterised by the means of pull-off tests, favouring a discussion on the suitability and limitations of these tests on rammed-earth/LC-TRM systems.This work was partly financed by FEDER funds through the Opera-tional Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth-PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737) . This research was partly funded by the Portuguese Foundation for Science and Technology (FCT) through the Grant No PD/BD/150385/2019. The funding provided by the Erasmus ELARCH (Euro Latin-America Partnership in Natural Risk mitigation and protection of the Cultural Heritage) 552129-EM-1-2014-1-IT-ERA MUNDUS-EMA21 Program is also gratefully acknowledged

Effect of light-curing units and activation mode on polymerization shrinkage and shrinkage stress of composite resins

The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (p<0.05), and the stress data were analyzed by one-way ANOVA and Tukey's test (p<0.05). Shrinkage and stress means of Bisfil 2B were statistically significant lower than those of Z100, A110 and SureFil. In general, the PD mode reduced the contraction and the stress values when compared to CM. LED generated the same stress as QTH in conventional mode. Regardless of the activation mode, SureFil produced lower contraction and stress values than the other light-cured resins. Conversely, Z100 and A110 produced the greatest contraction and stress values. As expected, the chemically cured resin generated lower shrinkage and stress than the light-cured resins. In conclusion, The PD mode effectively decreased contraction stress for Z100 and A110. Development of stress in light-cured resins depended on the shrinkage value

Effect of light-curing units and activation mode on polymerization shrinkage and shrinkage stress of composite resins

The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation upon polymerization was measured by the strain gauge method. The shrinkage stress was measured by photoelastic analysis. The polymerization shrinkage data were analyzed statistically using two-way ANOVA and Tukey test (

Testing allele homogeneity: the problem of nested hypotheses

Background: The evaluation of associations between genotypes and diseases in a case-control framework plays an important role in genetic epidemiology. This paper focuses on the evaluation of the homogeneity of both genotypic and allelic frequencies. The traditional test that is used to check allelic homogeneity is known to be valid only under Hardy-Weinberg equilibrium, a property that may not hold in practice. Results: We first describe the flaws of the traditional (chi-squared) tests for both allelic and genotypic homogeneity. Besides the known problem of the allelic procedure, we show that whenever these tests are used, an incoherence may arise: sometimes the genotypic homogeneity hypothesis is not rejected, but the allelic hypothesis is. As we argue, this is logically impossible. Some methods that were recently proposed implicitly rely on the idea that this does not happen. In an attempt to correct this incoherence, we describe an alternative frequentist approach that is appropriate even when Hardy-Weinberg equilibrium does not hold. It is then shown that the problem remains and is intrinsic of frequentist procedures. Finally, we introduce the Full Bayesian Significance Test to test both hypotheses and prove that the incoherence cannot happen with these new tests. To illustrate this, all five tests are applied to real and simulated datasets. Using the celebrated power analysis, we show that the Bayesian method is comparable to the frequentist one and has the advantage of being coherent. Conclusions: Contrary to more traditional approaches, the Full Bayesian Significance Test for association studies provides a simple, coherent and powerful tool for detecting associations

Preload and torque removal evaluation of three different abutment screws for single standing implant restorations

Several authors still consider the mechanical problems of fracture and component loosening as the main causes of failure of implant-supported restorations. The purpose of this in vitro study was to compare the preload of three types of screw for transmucosal abutment attachment used in single implant-supported prosthesis through strain gauge and removal torque measurements. Three external hex fixtures were used, and each received a transmucosal abutment (Cera One®), which was fixed to the implant with its respective screw: Group A- gold screw, Group B- titanium screw and Group C- surface-treated titanium screw (Ti-Tite®). Ten screws of each type were attached applying a 30.07&plusmn;0.28 Ncm torque force and maintained in position for 5 minutes. After this, the preload values were measured using strain gauges and a measurement cell. Gold screws presented higher preload values (131.72&plusmn;8.98 N), followed by surface-treated titanium screws (97.78&plusmn;4.68 N) and titanium screws (37.03&plusmn;5.69 N). ANOVA (

Prognostic value of the immunohistochemistry correlation of Ki-67 and p53 in squamous cell carcinomas of the larynx

Prognostic histological factors may contribute to determine the evolution of this neoplasia. AIM: To correlate p53 and Ki-67 immunohistochemical expression with age, histological degree, lymph node involvement and pathological staging in patients with laryngeal epidermoid carcinomas. METHODS: We assessed thirty consecutive cases of laryngeal epidermoid carcinomas submitted to immunohistochemistry to check the expression of p53 e Ki-67 antibodies. RESULTS: Mean age was of 56.2 years and the immunoexpression of the markers was observed in the group with more than 50 years of age, especially that o the ki-67 antibody (p=0.032). There was no relation between p53 and Ki-67 with lymph node involvement. Ki-67 was expressed in 70% of the high histology level cases and in 80% in the low histology ones; while p53 was of 70% only in the high level cases. Pathology staging showed that in the group of advanced carcinomas, p53 expression was of 61.5%, while Ki-67 proved positive for the early cases (100%) and advanced (73.1%). CONCLUSION: There were no significant differences between p53 and Ki-67 immunoexpression in laryngeal epidermoid carcinoma, except in the group of patients with more than 50 years of age, when Ki-67 expression was significantly higher.Os fatores prognósticos histológicos podem colaborar para determinar a evolução desta neoplasia. OBJETIVO: Correlacionar a expressão imunoistoquímica do p53 e Ki-67 com idade, grau histológico, comprometimento de linfonodos e estadiamento patológico de pacientes com carcinomas epidermóides de laringe. MÉTODO: Foram avaliados trinta casos consecutivos de carcinomas epidermóides de laringe, submetidos à técnica de imunoistoquímica para verificar a expressão dos anticorpos p53 e Ki-67. RESULTADO: A idade média foi de 56,2 anos e a imunoexpressão dos marcadores foi mais observada no grupo com mais de 50 anos de idade, especialmente a do anticorpo Ki-67 (p=0,032). Não houve relação do p53 e Ki-67 com o comprometimento de linfonodos. O Ki-67 se expressou em 70% nos casos de alto grau histológico e 80% nos de baixo, enquanto o p53 em 70% apenas nos de alto grau. O estadiamento patológico mostrou que no grupo dos carcinomas avançados a expressão do p53 foi de 61,5%, enquanto o Ki-67 mostrou positividade para os casos precoces (100%) e avançados (73,1%). CONCLUSÃO: Não houve diferenças significantes entre a imunoexpressão do p53 e do Ki-67 em carcinomas epidermóides de laringe, exceto no grupo de pacientes com mais de 50 anos, onde a expressão do Ki-67 foi significativamente maior.Universidade Luterana do Brasil Serviço de Anatomia PatológicaUniversidade Luterana do BrasilFFFCMPA Programa de Pós Graduação em PatologiaFFFCMPAUFRGSUniversidade Luterana do Brasil Serviço de PatologiaUNIFESPUniversidade de PittsburghUniversidade Luterana do Brasil Serviço de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoUFRGS Departamento de Ciências MorfológicasUNIFESPSciEL

Lesões pancreáticas em Doença de Chagas aguda experimental

BACKGROUND: Chagas' disease is an endemic tropical affliction found from southern United States to Argentina. The acute phase of this disease is difficult to study in man because the symptoms are non-specific and most cases require no medical assistance. Experimental models have been developed for sequential studies, and intense parasitism in all organs and tissues, including the pancreas, have been detected in the acute phase. PURPOSE: To evaluate the involvement of the pancreas in acute experimental Chagas' disease in a mouse model by histopathological characterization. CASUISTIC AND METHODS: Ten BALBc mice, about 20 g, injected i.p. with 100 000 forms of the Y strain of Trypanosoma cruzi were used. The animals were sacrificed after 14 days of infection. Fragments of pancreas were processed by conventional paraffin embedding and hematoxylin-eosin staining. RESULTS: Ruptured pseudocysts and release of parasites to the extracellular medium caused by necrosis of acinar and duct cells and foci of fat were the most striking histopathological features of acute Chagasic pancreatitis. CONCLUSION: Parasitism is the main cause of acute pancreatitis in Chagas' disease.INTRODUÇÃO: A Doença de Chagas é uma endemia tropical encontrada desde o sul dos Estados Unidos até a Argentina. Os estudos de fase aguda da doença são difíceis de serem realizados em seres humanos porque os sintomas são inespecíficos e a maioria dos casos não requer socorro médico. Em modelos experimentais desenvolvidos a doença aguda aparece com intenso parasitismo em todos os órgãos e tecidos. OBJETIVO: Caracterizar histopatologicamente o envolvimento pancreático na Doença de Chagas aguda experimental. CASUÍSTICA E MÉTODOS: Com esta finalidade utilizamos animais inoculados intraperitonialmente com 100.000 formas de cepa Y de Trypanosoma cruzi. Os animais foram sacrificados após 14 dias de infecção e os fragmentos colhidos foram processados em parafina e corados pela H&E. RESULTADOS: As características histopatológicas mais importantes da pancreatite aguda na Doença de Chagas experimental são: pseudocistos intensamente parasitados, íntegros ou rompidos, parasitas no espaço extracelular, necrose de células acinares e ductais, além de focos de esteatonecrose. CONCLUSÃO: O parasitismo dos tecidos é o principal mecanismo patogenético da pancreatite aguda na Doença de Chagas

Diagnóstico estratégico: um estudo de caso na empresa comércio de componentes automotivos Lazzaretti Ltda. / Strategic diagnosis: a case study in the company comércio de componentes automotivos Lazzaretti Ltda.

O objetivo foi analisar através de um diagnóstico estratégico na empresa Comércio de Componentes Automotivos Lazzaretti Ltda, como a vantagem competitiva pode contribuir estruturalmente para seu resultado financeiro. Para isso, buscou-se através de uma metodologia exploratória/descritiva, com a abordagem de estudo de caso e de pesquisa qualitativa, informações sobre a visão intrínseca dos clientes, dos funcionários, dos fornecedores e gerentes da organização, que pudessem responder aos objetivos da pesquisa. Paralelamente, construiu-se a matriz de SWOT com o intuito de potencializar análises de seu potencial de mercado. Concluiu-se que os gestores têm ciência da importância do planejamento estratégico e infere-se que a falta de tempo é o que impede o seu desenvolvimento das estratégias empresariais. Identifica-se na desorganização, a falta de comunicação e o atraso na entrega dos automóveis os principais pontos a se melhorar na organização, visto que esta encontra-se em postura estratégica de desenvolvimento