Stepped-bend Substrate Integrated Waveguide to Rectangular Waveguide Transition

A new wideband transition between substrate integrated waveguide (SIW) and rectangular waveguide (RWG) that resembles a right angle waveguide E-bend at Ku/K band is presented. The transition has removable but stable mounting, requires only PCB fabrication and has adaptable quality and bandwidth characteristics depending on the number of substrate layers used.

Développement de la polymérisation par (hétéro)arylation directe pour l’électronique organique

L’électronique organique suscite un intérêt grandissant en recherche grâce aux nouvelles possibilités qu’elle offre pour faciliter l’intégration de dispositifs électroniques dans nos vies. Grâce à elle, il est possible d’envisager des produits légers, flexibles et peu coûteux à produire. Les classes majeures de dispositifs étudiées sont les cellules photovoltaïques organiques (CPO) et les transistors organiques à effet de champ (TOEC). Dans les dernières années, une attention particulière a été portée sur les méthodes de polymérisation des matériaux organiques entrant dans la fabrication de ces dispositifs. La polymérisation par (hétéro)arylation directe (PHAD) catalysée au Pd offre une synthèse sans dérivé organométallique utilisant simplement un lien C-H aromatique, ce qui facilite la purification, diminue le nombre d’étapes et rend possible la production de matériaux à plus faible coût. De plus, la PHAD permet la préparation de matériaux qui était difficile, voire impossible, à obtenir auparavant. Cependant, l’inconvénient majeur de la PHAD reste sa limitation à certaines classes de polymères possédant des monomères ayant des positions bloquées favorisant qu’une seule paire de liaisons C-H. Dans le cadre de ces travaux de doctorat, l’objectif général est d’étudier la polymérisation par PHAD afin d’accéder à des classes de monomères qui n’étaient pas envisageables auparavant et à étendre l’application de cet outil dans le domaine des polymères conjugués. Plus spécifiquement, nous avons étudié l’utilisation de groupements protecteurs et partants sur des unités de benzodithiophènes et de bithiophène-silylés. Suivant ces résultats, nos travaux ont porté sur la polymérisation de dérivés de bithiophènes avec des bromo(aryle)s, une classe de polymères fréquemment utilisée en électronique organique mais qui était jugée impossible à polymériser par PHAD auparavant. Cette étude a montré l’importance de contrôler la PHAD afin d’obtenir le polymère souhaité. Finalement, nous avons étudié l’effet du système catalytique sur le taux de β−ramifications lors de la synthèse de polymères à base de thiophènes. Dans cette dernière étude, nous avons démontré l’importance d’utiliser des outils de caractérisation adéquats afin de confirmer la qualité des polymères obtenus.

Tratamento da classe II divisão 1 na dentição mista

Introdução: Os indivíduos portadores da má oclusão de Classe II Divisão 1 possuem diversas etiologias e podem ser encontrados em todas as etnias. As suas características clínicas e radiográficas se agravam com o crescimento e uma vez não tratada, continuam com esta má oclusão por toda sua vida. Para o tratamento ortodôntico na dentição mista recorre-se a dispositivos como aparelhos extra-orais, aparelhos funcionais fixos e removíveis. Objetivo: O objetivo deste trabalho é fazer uma revisão sobre o diagnóstico e tratamento da Classe II Divisão 1 na dentição mista, salientando a importância do tratamento nesta fase. Materiais e Métodos: Para a concretização do presente trabalho foi realizada uma revisão bibliográfica no presente ano, recorrendo-se ao livro “Ortodontia Contemporânea” do autor William Proffit, diversos motores de busca online, nomeadamente, PubMed, Medline, Elsevier e Scholar Google, utilizando como palavras-chave: “Class II Division 1”, “Mixed Dentition”, “Functional Appliance”, “Extra-Oral Appliance”, e revistas de Ortodontia, nomeadamente, American Journal of Orthodontics, Seminars in Orthodontics, The Angle Orthodontist e Dental Press de Ortodontia e Ortopedia Facial. A pesquisa foi realizada sem qualquer tipo de limites temporais, sendo dada uma maior importância a artigos mais recentes. Os artigos foram selecionados segundo o seu rigor científico e interesse para o tema. Numa fase mais avançada de revisão bibliográfica foram usados artigos citados na bibliografia dos artigos selecionados na primeira pesquisa efetuada. Conclusão: A dentição mista é considerada a fase ideal para iniciar o diagnóstico, prevenção, interceção e possível correção dos problemas dentários e/ou esqueléticos associados a uma Classe II Divisão 1. A Ortopedia Funcional dos Maxilares, removível ou fixa, e o uso de aparelhos extra-orais constituem recursos terapêuticos disponíveis para o tratamento desta má oclusão.

A importância da impressão funcional - técnica modelo modificado em prótese parcial removível de extremo livre

A Prótese Parcial Removível esquelética na reabilitação de pacientes edêntulos parciais tem sido uma opção acessível, rápida e viável de restabelecer a função estética e fonética dos dentes perdidos, porém a grande problemática em torno deste tipo de reabilitação está nos casos de extremos livres uni e bilaterais que dependem do rebordo residual para sustentação, devido à falta de pilar posterior que pode comprometer a retenção e principalmente a estabilidade da prótese que estará sujeita a deslocamentos constantes durante a dinâmica dos movimentos funcionais. Na literatura é relatado que todos os conhecimentos devem ser observados a quando da confecção deste tipo de prótese, as explicações e orientações como se comporta este tipo de prótese e os cuidados que o paciente tem que ter, e principalmente as condições biológicas dos tecidos de suporte são da responsabilidade do Médico Dentista o qual ao ter em conta e transmitir estes conhecimentos no momento do planeamento consegue assim minimizar os riscos de fracasso. A impressão funcional é de extrema importância para o sucesso da reabilitação com este tipo de prótese, mais especificamente a técnica do modelo modificado, que o objeto deste trabalho é realçar a sua utilização. Sendo de especial interesse para a Medicina Dentária pela necessidade e demanda do tratamento clínico, quanto para o ensino nas universidades. Dessa forma este trabalho visa mostrar a importância da impressão funcional na Prótese Parcial Removível esquelética de extremo livre, em especial o modelo modificado, pois ela visa obter melhor estabilidade, suporte e retenção para conseguir um melhor conforto para o paciente, mantendo a integridade do periodonto e dos dentes de apoio, obtendo assim um bom prognóstico e sucesso no procedimento realizado, como forma de fazer com que este procedimento responda tanto a expectativa do paciente como da equipe que a confecciona.

The TOMO-ETNA experiment: an imaging active campaign at Mt. Etna volcano. Context, main objectives, working-plans and involved research projects

The TOMO-ETNA experiment was devised to image of the crust underlying the volcanic edifice and, possibly, its plumbing system by using passive and active refraction/reflection seismic methods. This experiment included activities both on-land and offshore with the main objective of obtaining a new high-resolution seismic tomography to improve the knowledge of the crustal structures existing beneath the Etna volcano and northeast Sicily up to Aeolian Islands. The TOMO ETNA experiment was divided in two phases. The first phase started on June 15, 2014 and finalized on July 24, 2014, with the withdrawal of two removable seismic networks (a Short Period Network and a Broadband network composed by 80 and 20 stations respectively) deployed at Etna volcano and surrounding areas. During this first phase the oceanographic research vessel “Sarmiento de Gamboa” and the hydro-oceanographic vessel “Galatea” performed the offshore activities, which includes the deployment of ocean bottom seismometers (OBS), air-gun shooting for Wide Angle Seismic refraction (WAS), Multi-Channel Seismic (MCS) reflection surveys, magnetic surveys and ROV (Remotely Operated Vehicle) dives. This phase finished with the recovery of the short period seismic network. In the second phase the Broadband seismic network remained operative until October 28, 2014, and the R/V “Aegaeo” performed additional MCS surveys during November 19-27, 2014. Overall, the information deriving from TOMO-ETNA experiment could provide the answer to many uncertainties that have arisen while exploiting the large amount of data provided by the cutting-edge monitoring systems of Etna volcano and seismogenic area of eastern Sicily.

Análise mecânica e microestrutural das ligas de cobalto-cromo de uso odontológico após sucessivas refundições

The cobalt-chromium alloy is extensively used in the Odontology for the confection of metallic scaffolding in partial removable denture. During the last few years, it has been reported an increasing number of premature imperfections, with a few months of prosthesis use. The manufacture of these components is made in prosthetic laboratories and normally involves recasting, using parts of casting alloy and parts of virgin alloy. Therefore, the objective of the present study was to analyze the mechanical properties of a commercial cobalt-chromium alloy of odontological use after successive recasting, searching information to guide the dental prosthesis laboratories in the correct manipulation of the cobalt-chromium alloy in the process of casting and the possible limits of recasting in the mechanical properties of this material. Seven sample groups were confectioned, each one containing five test bodies, divided in the following way: G1: casting only with virgin alloy; G2: casting with 50% of the alloy of the G1 + 50% of virgin alloy; G3: casting with 50% of the alloy of the G2 + 50% of virgin alloy; G4: casting with 50% of the alloy of the G3 + 50% of virgin alloy; G5: 50% of alloy of the G4 + 50% of virgin alloy; G6: 50% of alloy of the G5 + 50% of virgin alloy and finally the G7, only with recasting alloy. The modifications in the mechanical behavior of the alloy were evaluated. Moreover, it was carried the micro structural characterization of the material by optic and electronic scanning microscopy, and X ray diffraction.and fluorescence looking into the correlatation of the mechanical alterations with structural modifications of the material caused by successive recasting process. Generally the results showed alterations in the fracture energy of the alloy after successive recasting, resulting mainly of the increasing presence of pores and large voids, characteristic of the casting material. Thus, the interpretation of the results showed that the material did not reveal significant differences with respect to the tensile strength or elastic limit, as a function of successive recasting. The elastic modulus increased from the third recasting cycle on, indicating that the material can be recast only twice. The fracture energy of the material decreased, as the number of recasting cycles increased. With respect to the microhardness, the statistical analyses showedno significant differences. Electronic scanning microscopy revealed the presence of imperfections and defects, resulting of the recasting process. X ray diffraction and fluorescence did not show alterations in the composition of the alloy or the formation of crystalline phases between the analyzed groups. The optical micrographs showed an increasing number of voids and porosity as the material was recast. Therefore, the general conclusion of this study is that the successive recasting of of Co-Cr alloys affects the mechanical properties of the material, consequently leading to the failure of the prosthetic work. Based on the results, the best recommendadition is that the use of the material should be limited to two recasting cycles

Adhesives for fixed orthodontic bands

Background: Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. :Objectives: To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of: (1) how often the bands come off during treatment; and (2) whether they protect the banded teeth against decay during fixed appliance treatment. Search methods: The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Selection criteria: Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. Data collection and analysis: All review authors were involved in study selection, validity assessment and data extraction without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. Main results: Five RCTs and three CCTs were identified as meeting the review's inclusion criteria. All the included trials were of split-mouth design. Four trials compared chemically cured zinc phosphate and chemically cured glass ionomer; three trials compared chemically cured glass ionomer cement with light cured compomer; one trial compared chemically cured glass ionomer with a chemically cured glass phosphonate. Data analysis was often inappropriate within the studies meeting the inclusion criteria. Authors' conclusions: There is insufficient high quality evidence with regard to the most effective adhesive for attaching orthodontic bands to molar teeth. Further RCTs are required.