689 research outputs found

    SYNTAX II and SYNTAX III trials: What is the take home message for surgeons?

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    Percutaneous coronary intervention (PCI) has evolved greatly in the last 40 years since its introduction by Andreas Grüntzig in 1977. Since then, we've observed an evolution in balloons, the development of stents, changes in stent structure, development of drug eluting stents, improvements in strut design, thickness and even their polymeric coating. Most recently we saw the rise and "fall" of bioabsorbable scaffolds for PCI. Trials with the most diverse devices for PCI and diagnostic techniques have been conducted. Two of the most recent trials were reported in the last year and deserve special attention-SYNTAX II and SYNTAX III. These trials are completely different in design but present valuable information for doctors managing coronary artery disease (CAD). Both trials take into account contemporary technology for assessing and treating CAD. The first uses so-called "state-of-the-art" PCI and compares the outcomes of that approach with the outcomes of the PCI arm of the pivotal SYNTAX trial. SYNTAX III Revolution on the other hand does not focus on clinical endpoints: it is a blinded trial that does not randomize patients but randomizes doctors ("the heart team") to make a decision on the best treatment for complex CAD. This decision was based either on multi-slice CT with physiological assessment using FFRCT or on conventional angiography. In this review we bring the most important aspects of those trials and the key messages for surgeons together; also, what the surgeon may expect in the future after the publication of these interesting concepts

    Avaliação da Influência de Implementos de Plantio Direto do Milho com Tomografia de Raios Gama.

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    Determinants of surgeon choice in cases of suspected implant rupture following mastectomy or aesthetic breast surgery: Clinical implications

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    Implant ruptures may be diagnosed by physical examination, ultrasound (US), and magnetic resonance imaging (MRI). The absence of standard guidelines to approach to implant ruptures may cause unnecessary surgical revisions in the absence of radiological confirmation of prosthetic damages.The purpose of this study was to analyze the diagnostic procedures applied to patients with suspected prosthetic rupture and surgeon choices to perform a revision or to plan a clinical and radiological follow-up.We conducted a retrospective study on 62 women submitted to revision surgery due to radiological diagnosis of suspected implant rupture, following mastectomy or aesthetic reconstruction, and admitted to a Plastic Surgery Department between 2008 and 2018.Seventy-three implants, believed to be ruptured, were explanted. One-third of these were intact and unnecessarily explanted. US associated with MRI evaluation resulted in the most helpful diagnostical method.A standardized clinical and radiological approach is essential to manage breast implant ruptures successfully. An innovative protocol is proposed in order to: ensure the appropriate management of implant ruptures and prevent unnecessary surgical revisions; reduce the risk of claims for medical malpractice in cases of unsatisfactory final aesthetic results or worse than before

    Uso da tomografia computadorizada para estudo do ambiente solo-semente de soja sob sistema de plantio direto.

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    bitstream/CNPDIA-2009-09/11890/1/CT93_2008.pd

    Failure Physics and Reliability of GaN-Based HEMTs for Microwave and Millimeter-Wave Applications: A Review of Consolidated Data and Recent Results

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    Herein, the results are reviewed concerning reliability of high-electron mobility transistors (HEMTs) based on GaN, which currently represent the technology of choice for high-efficiency microwave and millimeter-wave power amplifiers. Several failure mechanisms of these devices are extensively studied, including converse piezoelectric effects, formation of conductive percolation paths at the edge of gate toward the drain, surface oxidation of GaN, time-dependent breakdown of GaN buffer, and of field-plate dielectric. For GaN HEMTs with scaled gate length, the simultaneous control of short-channel effects, deep-level dispersion, and hot-electron-induced degradation requires a careful optimization of epitaxial material quality and device design

    Temporal variability of waves at the proton cyclotron frequency upstream from Mars: Implications for Mars distant hydrogen exosphere

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    We report on the temporal variability of the occurrence of waves at the local proton cyclotron frequency upstream from the Martian bow shock from Mars Global Surveyor observations during the first aerobraking and science phasing orbit periods. Observations at high southern latitudes during minimum-to-mean solar activity show that the wave occurrence rate is significantly higher around perihelion/ southern summer solstice than around the spring and autumn equinoxes. A similar trend is observed in the hydrogen (H) exospheric density profiles over the Martian dayside and South Pole obtained from a model including UV thermospheric heating effects. In spite of the complexity in the ion pickup and plasma wave generation and evolution processes, these results support the idea that variations in the occurrence of waves could be used to study the temporal evolution of the distant Martian H corona and its coupling with the thermosphere at altitudes currently inaccessible to direct measurements.Fil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Chaufray, J. Y.. LATMOS; FranciaFil: Gomez, Daniel Osvaldo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mazelle, C.. IRAP; FranciaFil: Delva, M.. IWF-ÖAW; AustriaFil: Modolo, R.. LATMOS; FranciaFil: González Galindo, F.. Instituto de Astrofísica de Andalucía; EspañaFil: Brain, D. A.. University of Colorado Boulder; Estados Unido

    An overview of solvent extraction processes developed in Europe for advanced nuclear fuel recycling, Part 2 — homogeneous recycling

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    The hydrometallurgical separation concepts for the recycling of irradiated nuclear fuels developed in Europe are presented and discussed. Whilst Part 1 of the review focused on concepts for heterogeneous recycling of minor actinides, this article focuses on group recycling of transuranic actinides, which would support homogeneous recycling scenarios. Most of these concepts were developed within European collaborative projects and involve solvent extraction processes separating all the actinides (U-Cm) in two cycles. The first cycle uses a monoamide extractant to recover uranium leaving all the transuranic actinides in the aqueous raffinate with the fission products. The second cycle aims for a group recovery of the transuranium elements and several strategies have been proposed for this stage. In this review article, the various solvent extraction processes are summarised and the key features of the process schemes are compared
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