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We study the frictional drag between two graphene layers placed inside a cavity. We show that the drag has two contributions: the well-known Coulomb drag, and a novel photon-mediated drag. The latter arises from a cavity-mediated interaction in which the backscattering is not suppressed and the screening is relatively weak. As a result, the photon-mediated drag resistivity in the Fermi-liquid regime acquires corrections to the usual quadratic temperature dependence, has a slow decay as the interlayer separationdincreases, and depends on the carrier densitynasρD∼1/n2. Thus, whereas for smalldandnthe Coulomb drag dominates, as these parameters increase the drag transitions to a purely photon-mediated drag. The onset of this transition depends on the electromagnetic field enhancement inside the cavity.

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This data article comprises experimental data to investigate the nonlinear dynamic behavior of the Orion beam structure, which consists of two duraluminum beams assembled by bolted joints. To retain contact on a small area between both beams, this new lap-joint configuration proposes contact patches at each bolt connection. The Orion beam suggests an assembly configuration that associates bolts dedicated to 'static' functions and to those to perform 'damping' functions. This ensures a significant increase in the structural damping without degrading the structural stiffness. Experiments have been performed on the laboratory ple Vibration and Acoustic, located at FEMTO-ST Institute, CNRS/UFC/ENSMM/UTBM, Department of Applied Mechanics, 24 chemin de lEpitaphe, 25000 Besanon, France. This data aim to provide the geometrical step and all the experimental measurements performed on our lap-joint for several excitation amplitudes and tightening torques, as far as possible and with the degree of uncertainties of the measurements. By doing so, we intend to provide experimental data, as precise and reliable as possible, which are required to progress on the numerical modelling of the dry friction damping in assembly structures. This Data in Brief article is an additional research item alongside the following paper published in the Mechanical Systems and Signal Processing journal: R. O. Teloli, P. Butaud, G. Chevallier and S. da Silva, Good practices for designing and experimental testing of dynamically excited jointed structures: the Orion beam.

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Tectonic pseudotachylytes are thought to be unique to certain water-deficient seismogenic environments and their presence is considered to be rare in the geological record. Here, we present field and experimental evidence that frictional melting can occur in hydrothermal fluid-rich faults hosted in the continental crust. Pseudotachylytes were found in the >40 km-long Bolfín Fault Zone of the Atacama Fault System, within two ca. 1 m-thick (ultra)cataclastic strands hosted in a damage-zone made of chlorite-epidote-rich hydrothermally altered tonalite. This alteration state indicates that hydrothermal fluids were active during the fault development. Pseudotachylytes, characterized by presenting amygdales, cut and are cut by chlorite-, epidote- and calcite-bearing veins. In turn, crosscutting relationship with the hydrothermal veins indicates pseudotachylytes were formed during this period of fluid activity. Rotary shear experiments conducted on bare surfaces of hydrothermally altered rocks at seismic slip velocities (3 m s-1) resulted in the production of vesiculated pseudotachylytes both at dry and water-pressurized conditions, with melt lubrication as the primary mechanism for fault dynamic weakening. The presented evidence challenges the common hypothesis that pseudotachylytes are limited to fluid-deficient environments, and gives insights into the ancient seismic activity of the system. Both field observations and experimental evidence, indicate that pseudotachylytes may easily be produced in hydrothermal environments, and could be a common co-seismic fault product. Consequently, melt lubrication could be considered one of the most efficient seismic dynamic weakening mechanisms in crystalline basement rocks of the continental crust.

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ABSTRACT Introduction: Proximal stripping of enamel is a routine clinical procedure employed in orthodontics to create space or for balancing tooth size discrepancies. This procedure may result in heat transfer to the pulp, predisposing it to histopathological changes and necrosis of the pulp tissue. Objective: To measure the temperature changes in the pulp chamber during different stripping procedures. Methods: 80 proximal surfaces of 40 extracted human premolar teeth were stripped using four techniques: diamond burs in air-rotor handpiece with air-water spray; diamond burs in micromotor handpiece, with and without a coolant spray; and hand-held diamond strips. A J-type thermocouple connected to a digital thermometer was inserted into the pulp chamber for evaluation of temperature during the stripping procedure. Results: An increase in the pulpal temperature was observed for all stripping method. Diamond burs in micromotor handpiece without coolant resulted in the higher increase in temperature (3.5oC), followed by hand-held diamond strips (2.8oC), diamond burs in air-rotor with air-water spray (1.9oC); and the smallest increase was seen with diamond burs in micromotor handpiece with coolant (1.65oC). None of the techniques resulted in temperature increase above the critical level of 5.5oC. Conclusion: Frictional heat produced with different stripping techniques results in increase in the pulpal temperature, therefore, caution is advised during this procedure. A coolant spray can limit the increase in temperature of the pulp.

RESUMO Introdução: o desgaste proximal do esmalte é um procedimento clínico rotineiro utilizado na Ortodontia para se criar espaços ou equilibrar discrepâncias de tamanho dentário. Esse procedimento pode resultar em transferência de calor para a polpa, predispondo-a a mudanças histopatológicas e necrose do tecido pulpar. Objetivo: medir as mudanças de temperatura na câmara pulpar durante diferentes procedimentos de desgaste interproximal. Métodos: 80 superfícies proximais de 40 pré-molares humanos foram desgastadas utilizando-se quatro técnicas diferentes: brocas diamantadas em motor a ar (alta rotação) com spray de água e ar; brocas diamantadas em micromotor (baixa rotação) com e sem spray de resfriamento; e tiras diamantadas manuais. Um par termoelétrico do tipo J conectado a um termômetro digital foi inserido na câmara pulpar para avaliação da temperatura durante o desgaste proximal. Resultados: foi observado um aumento da temperatura da câmara pulpar em todos os métodos de desgaste proximal. As brocas diamantadas em micromotor sem resfriamento foram responsáveis pelo maior aumento da temperatura (3,5oC), seguidas pelas lixas diamantadas manuais (2,8oC) e brocas diamantadas em motor a ar (alta rotação) com spray de água e ar (1,9oC). O menor aumento foi observado com as brocas diamantadas em micromotor (baixa rotação) com resfriamento (1,65oC). Nenhuma das técnicas elevou a temperatura acima do nível crítico de 5,5oC. Conclusão: o aquecimento friccional produzido pelas diferentes técnicas de desgaste proximal levou ao aumento da temperatura da câmara pulpar; assim, cuidados devem ser tomados durante esse procedimento. O spray de água e ar pode limitar o aumento da temperatura da polpa.

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Objetivo: Presentamos una serie de pacientes con dolor crónico de tobillo y estudios por imágenes negativos, en los que hallamos solamente una banda fibrosa intraarticular como causa probable del dolor en la artroscopia diagnóstica. Métodos: Entre el año 2010 y 2016 se realizaron 212 artroscopias anteriores de tobillo. En 19 pacientes (8,96%) se encontró una banda fibrosa intrarticular. En 13 pacientes se encontraban asociadas con otras patologías y solo en 6 pacientes (2,83%) fueron aisladas, sin lesión asociada. El promedio de edad fue de 40,42 años. El seguimiento promedio de 20,42 meses. La mayoría de los pacientes fueron atendidos en centros de aseguradoras de riesgo de trabajo. Resultados: Se utilizó el score AOFAS con un promedio para el preoperatorio de 55,63 y para el postoperatorio de 92.26. No hubo complicaciones en esta serie. Conclusiones: La banda fibrosa es una patología infrecuente, con sintomatología clínica similar a la de otras patologías que producen un síndrome friccional anterior de partes blandas del tobillo. La mayoría tenía antecedentes traumáticos. Los estudios por imágenes utilizados fueron la radiografía y la Resonancia. Ninguno de ellos fue de utilidad en el diagnóstico. La banda fibrosa es una de las diferentes formas de impingement en la cara anterior del tobillo y puede ser una causa de fricción y dolor. Dado que los estudios por imágenes no fueron concluyentes, la artroscopía fue nuestro método de elección para el diagnóstico y tratamiento en los pacientes con dolor crónico de tobillo con imágenes negativas. Tipo de trabajo: Serie de casos. Nivel de evidencia: IV.

Purpose: We present a series of patients with chronic anterior ankle pain and negative imaging studies, in which we found an isolated fibrous intrarticular band as a probable cause of pain in diagnostic arthroscopy. Methods: Between 2010 and 2016 we performed 212 anterior ankle arthroscopies. In 19 patients (8,96%) a fibrous web like band was found. In 13 cases they were associated with other diseases and only 6 of them (2.83 %) were isolated. Average age was 42 years. Follow up was between 4 months and 3 years (average 20.42 months). Most of them were workers compensation patients. Results: We used the AOFAS scores with an average value of 55,63 preoperative and 92.26 points postoperative. No complications were found in this series. Conclusions: Intra articular fibrous band is an infrequent pathology, with clinical presentation similar to other soft tissues anterior impingement. Most of them had previous trauma. Imaging studies performed were radiographs and MRI, but they have not proven to be useful due to their low or none sensitivity to this condition. Intra articular fibrous bands is one of the causes of anterior impingement of the ankle, and may be a cause of friction and pain. Most of them had history of previous trauma. Imaging studies were not conclusive, and arthroscopy was our election method for diagnosis and treatment in patients with chronic ankle pain and negative imaging studies. Type of study: Case series. Level Of Evidence: IV.

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ABSTRACT Glass microbeads are frequently used in analog physical modeling to simulate weak detachment zones but have been neglected in models of thrust wedges. Microbeads differ from quartz sand in grain shape and in low angle of internal friction. In this study, we compared the structural characteristics of microbeads and sand wedges. To obtain a better picture of their mechanical behavior, we determined the physical and frictional properties of microbeads using polarizing and scanning electron microscopy and ring-shear tests, respectively. We built shortening experiments with different basal frictions and measured the thickness, slope and length of the wedges and also the fault spacings. All the microbeads experiments revealed wedge geometries that were consistent with previous studies that have been performed with sand. However, the deformation features in the microbeads shortened over low to intermediate basal frictions were slightly different. Microbeads produced different fault geometries than sand as well as a different grain flow. In addition, they produced slip on minor faults, which was associated with distributed deformation and gave the microbeads wedges the appearance of disharmonic folds. We concluded that the glass microbeads may be used to simulate relatively competent rocks, like carbonates, which may be characterized by small-scale deformation features.

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The flavoprotein old yellow enzyme of Trypanosoma cruzi (TcOYE) is an oxidoreductase that uses NAD(P)H as cofactor. This enzyme is clinically relevant due to its role in the action mechanism of some trypanocidal drugs used in the treatment of Chagas' disease by producing reactive oxygen species. In this work, the recombinant enzyme TcOYE was produced and collectively, X-ray crystallography, small angle X-ray scattering, analytical ultracentrifugation and molecular dynamics provided a detailed description of its structure, specificity and hydrodynamic behavior. The crystallographic structure at 1.27Å showed a classical (α/ß)8 fold with the FMN prosthetic group buried at the positively-charged active-site cleft. In solution, TcOYE behaved as a globular monomer, but it exhibited a molecular envelope larger than that observed in the crystal structure, suggesting intrinsic protein flexibility. Moreover, the binding mode of ß-lapachone, a trypanocidal agent, and other naphthoquinones was investigated by molecular docking and dynamics suggesting that their binding to TcOYE are stabilized mainly by interactions with the isoalloxazine ring from FMN and residues from the active-site pocket.

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Introducción: este reporte clínico pretende presentar los resultados obtenidos con un sistema de implantes que modifica el protocolo convencional quirúrgico en cuanto a las revoluciones de fresado, no uso de irrigación, recolección del hueso nativo y opciones protésicas como la corona integrada al pilar, la cementación extraoral y la posición universal del pilar. En cuanto a su diseño se destaca el uso de implantes cortos, plataforma reducida, aletas laterales, conexión al pilar por cierrefriccional y superficie alterada. Métodos: se colocaron treinta implantes Bicon® de seis milímetros de longitud para restauración de diente único en veintidós pacientes. Se hizo el protocolo quirúrgico de acuerdo con las recomendaciones del fabricante y endos fases quirúrgicas. Se hizo la cirugía de destape de cada implante y se cementaron todas las restauraciones metal-cerámicas. Resultados: se reporta 100% de oseointegración de los implantes al momento de la cirugía de destape, con ausencia de movilidado dolor durante la función, ausencia de exudado y normalidad de los tejidos blandos periimplantares; se reporta ausencia de radiolucidez en la evaluación radiográfica. Conclusión: en este estudio podemos concluir que con el protocolo quirúrgico modificado y el diseño del implante Bicon® (Bicon™ Dental Implants, Boston, MA) se logró el 100% de éxito en la oseointegraciónde treinta implantes cortos al momento de la cirugía de destape, con superficie alterada y plataforma reducida, colocados para la restauración de diente único en diferentes zonas de la cavidad oral.

Introduction: the purpose of this clinical report is to present the collected results with an implant system that modifies the classical protocol regarding drilling speed, use of irrigation, native bone collecting and prosthetic options including crown integrated to the abutment, extraoral cementing of the crown and universal position of abutment screw. Regarding implant design, it´s important to highlight the use of short implants, with reduced platform, lateral wings instead of screw threads, abutmentconnection by means of friction and modified implant surface. Methods: 30 Bicon® implants, all six-mm of length, were placed in order to perform single tooth restorations in 22 patients. The surgical protocol was performed according to indications of themanufacturer in two surgical stages. The implants were uncovered and all metal-ceramic crowns were cemented. Results: the percentage of osseointegration success was 100% at the time of uncovering, without pain or mobility during function, no signs ofinfection and healthy appearance of peri-implant tissues. There were no radiographic changes at the x-ray evaluation. Conclusion: considering the limitations of this study, it can be concluded that with the modified surgical protocol and the structural design of the Bicon® Implant (Bicon™ Dental Implants, Boston, MA) a 100% osseointegration success was achieved on 30 implants with modified surface and reduced platform, placed in different areas of the oral cavity for single-tooth restoration.

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Introdução: Uma das alternativas atuais para reabilitar pacientes com perda total ou parcial de dentes é o uso da carga imediata. Com a evolução das técnicas de cirurgia, o avanço dos métodos de diagnóstico, o conhecimento amplo da biologia dos tecidos envolvidos e a melhoria na qualidade dos implantes, a carga imediata, como modalidade reabilitadora, vem sendo consolidada cada vez mais. Objetivo: Descrever um caso inicial de carga imediata não funcional em um único elemento utilizando sistema friccional. Relato de caso: Ocaso refere-se a um paciente do gênero masculino, 35 anos de idade, com histórico de fratura do elemento 36. Após remoção de raízes e enxerto no alvéolo (homólogo, acompanhamento de seis meses), instalaram-se um implante e uma coroa temporária imediatamente. O sucesso da carga imediata pode estar ligado à ausência de micromovimentações do implante recém-colocado, à correta seleção do paciente, ao planejamento, ao desenho do implante e ao torque final. Conclusão: A carga imediata é uma opção viável de tratamento, até mesmo para implantação unitária, em que é indiscutível a presença de osso suficiente em qualidade e quantidade para que os resultados clínicos sejam positivos.

Introduction: A contemporary alternative to rehabilitate patients with partial or total loss of teeth is the immediate loading. Considering the evolution of surgical techniques, advances in diagnostic methods, wide biological knowledge of the involved tissues and improvements in the quality of implants, the immediate loading as a rehabilitative technique has been largely consolidated. Objective: To report an initial case of non-functional immediate loading of a single-tooth implant using frictional system. Case report: A 35-year-old male patient with a fracture history of the tooth 36 was treated. After removal of roots and alveolar grafting (homologous bone, 6 months monitoring) an implant was placed with immediate temporary crown. Success of the immediate loading technique can be related to absence of micromovements in the recently placed implant, to correct patient selection, to planning, to implant design and to final torque. Conclusion: Immediate loading of implants is a viable treatment option even for single-tooth implant, in which sufficient and adequate bone amount are essential for positive treatment outcomes.

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O objetivo do estudo foi avaliar o efeito da presença de canaleta metálica em braquetes estéticos, considerando-se a força de atrito, Clarity®(G1) e Transcend®(G2). Para tanto, foi utilizado um dispositivo adaptado a máquina EMIC DL2000 para simular uma situação de movimento de retração na mecânica de deslize. A movimentação simulada foi relacionada a um segmento da arcada superior do lado direito, de incisivo central ao segundo pré-molar. “Foram realizados 14 testes em duplicatas, com fios de aço inoxidável “.019X.025” e ligadura elástica convencional e de mesmo lote. A velocidade do ensaio foi de 10mm/min. Para cada teste realizado, foram trocados os fios e ligaduras. Os parâmetros avaliados foram atrito estático (AE), atrito dinâmico (AD) e força máxima (FM). Os dados foram tabulados e submetidos à análise estatística (Teste t de Student e Mann-Whitney, α=5%). Para G1, os resultados (Média±DP) foram: AE (681,2gf ± 26,4), AD (717,2gf ± 38,5), FM (787,8gf ± 40,8) e para G2: AE (442,3 gf ± 67,5), AD (466,0 gf ± 77,0) e FM (517,9gf ± 89,4). Houve diferença estatística significativa para todos os parâmetros avaliados (p<0,001). Concluiu-se que o braquete Clarity®, que possui canaleta metálica, gera maior atrito que o braquete Transcend®.

The aim of this study was to evaluate the effect of stainless steel slots in esthetic brackets considering frictional force. (Clarity®(G1) and Transcend®(G2). For this purpose a device adapted to an EMIC DL2000 machine was used to simulate a situation of the movement of retraction by sliding mechanics. The simulated movement was related to a segment of the maxillary arch on the right side, from the central incisor to the second premolar. Fourteen tests were performed in duplicate, with “.019X.025” stainless steel wires and conventional elastic ligatures of the same lot. The test speed was 10mm/min. For each test performed, the wires and ligatures were changed. The parameters evaluated were static friction (SF), dynamic friction (DF) and maximum force (MF). The data were tabulated and submitted to statistics analysis (Student’s-t and Mann-Whitney tests, α=5%). For G1, the results (Mean±SD) were: SF (681.2gf ± 26.4), DF (717.2gf ± 38.5), MF (787.8gf ± 40.8) and for G2: SF (442.3.2gf ± 67.5), DF (466.0.2gf ± 77.0), MF (517.8gf ± 89.4). There was statistically significant difference for all the parameters evaluated. (p<0.001). It was concluded that the Clarity® bracket which has a stainless steel slots, generates greater friction than the Transcend bracket®.

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