38 research outputs found

    Modellversuche Einlaufbauwerk Hinterdorfbach, Dielsdorf

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    Aufsatz veröffentlicht in: "Wasserbau-Symposium 2021: Wasserbau in Zeiten von Energiewende, Gewässerschutz und Klimawandel, Zurich, Switzerland, September 15-17, 2021, Band 1" veröffentlicht unter: https://doi.org/10.3929/ethz-b-00049975

    Quality assurance process within the RAdiosurgery for VENtricular TAchycardia (RAVENTA) trial for the fusion of electroanatomical mapping and radiotherapy planning imaging data in cardiac radioablation

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    A novel quality assurance process for electroanatomical mapping (EAM)-to-radiotherapy planning imaging (RTPI) target transport was assessed within the multi-center multi-platform framework of the RAdiosurgery for VENtricular TAchycardia (RAVENTA) trial. A stand-alone software (CARDIO-RT) was developed to enable platform independent registration of EAM and RTPI of the left ventricle (LV), based on pre-generated radiotherapy contours (RTC). LV-RTC were automatically segmented into the American-Heart-Association 17-segment-model and a manual 3D-3D method based on EAM 3D-geometry data and a semi-automated 2D-3D method based on EAM screenshot projections were developed. The quality of substrate transfer was evaluated in five clinical cases and the structural analyses showed substantial differences between manual target transfer and target transport using CARDIO-RT

    Tropheryma whipplei tricuspid endocarditis: a case report and review of the literature

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    INTRODUCTION: The main clinical manifestations of Whipple's disease are weight loss, arthropathy, diarrhea and abdominal pain. Cardiac involvement is frequently described. However, endocarditis is rare and is not usually the initial presentation of the disease. To the best of our knowledge, this is the first reported case of a patient with Tropheryma whipplei tricuspid endocarditis without any other valve involved and not presenting signs of arthralgia and abdominal involvement. CASE PRESENTATION: We report a case of a 50-year-old Caucasian man with tricuspid endocarditis caused by Tropheryma whipplei, showing signs of severe shock and an absence of other more classic clinical signs of Whipple's disease, such as arthralgia, abdominal pain and diarrhea. Tropheryma whipplei was documented by polymerase chain reaction of the blood and pleural fluid. The infection was treated with a combined treatment of doxycycline, hydroxychloroquine and sulfamethoxazole-trimethoprim for one year. CONCLUSION: Tropheryma whipplei infectious endocarditis should always be considered when facing a blood-culture negative endocarditis particularly in right-sided valves. Although not standardized yet, treatment of Tropheryma whipplei endocarditis should probably include a bactericidal antibiotic (such as doxycycline) and should be given over a prolonged period of time (a minimum of one year)

    Carbon Fiber/Polyether Ether Ketone (CF/PEEK) Implants Allow for More Effective Radiation in Long Bones

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    Background: Metallic implants show dose-modulating effects in radiotherapy and complicate its computed tomography (CT)-based planning. Dose deviations might not only affect the surrounding tissues due to backscattering and inadvertent dose increase but might also compromise the therapeutic effect to the target lesion due to beam attenuation. Later on, follow-up imaging is often obscured by metallic artefacts. Purposes: This study investigates the dosimetric impact of titanium and radiolucent carbon fiber/polyether ether ketone (CF/PEEK) implants during adjuvant radiation therapy in long bones. (1) Does the use of CF/PEEK implants allow for a more homogenous application of radiation? (2) Is the dose delivery to the target volume more efficient when using CF/PEEK implants? (3) Do CF/PEEK implants facilitate CT-based radiation therapy planning? Materials and methods: After CT-based planning, bone models of six ovine femora were irradiated within a water phantom in two immersion depths to simulate different soft-tissue envelopes. Plates and intramedullary nails of both titanium and CF/PEEK were investigated. Radiation dosage and distribution patterns were mapped using dosimetry films. Results: First, the planned implant-related beam attenuation was lower for the CF/PEEK plate (1% vs. 5%) and the CF/PEEK nail (2% vs. 9%) than for corresponding titanium implants. Secondly, the effective decrease of radiation dosage behind the implants was noticeably smaller when using CF/PEEK implants. The radiation dose was not significantly affected by the amount of surrounding soft tissues. A significant imaging artefact reduction was seen in all CF/PEEK models. Conclusion: CF/PEEK implants lead to a more reliable and more effective delivery of radiation dose to an osseous target volume. With regard to radiation therapy, the use of CF/PEEK implants appears to be particularly beneficial for intramedullary nails

    Hydropower potential in the periglacial environment of Switzerland under climate change

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    Hydropower is the most important domestic source of renewable energy in Switzerland. Many reservoirs are located in the periglacial environment of the Swiss Alps. Climate change and the changeover to a new energy system will challenge the existing infrastructure, but will also provide perspectives for new hydropower plants (HPPs). This study presents a framework for the systematic analysis of the hydropower potential of the periglacial Swiss Alps. The results are referenced to the Swiss Energy Strategy and other potential courses of action, such as upgrade of existing infrastructure. An evaluation matrix with 16 economical, environmental and social criteria for the consistent rating of all feasible sites is proposed. All criteria and their ratings are explained. It is demonstrated that the chosen methodology leads to a relatively stable ranking even for significantly different weighting models. Although being affected by uncertainties and remaining challenges, the methodology and results are sufficiently detailed for decision-making. Therefore, recommendations for future hydropower investments can be given. The results are strongly linked to Swiss boundary conditions, but the methodology itself is generally applicable for all glaciers worldwide, if the required input data are available.ISSN:2071-105

    Hydropower Potential in the Periglacial Environment of Switzerland under Climate Change

    No full text
    Hydropower is the most important domestic source of renewable energy in Switzerland. Many reservoirs are located in the periglacial environment of the Swiss Alps. Climate change and the changeover to a new energy system will challenge the existing infrastructure, but will also provide perspectives for new hydropower plants (HPPs). This study presents a framework for the systematic analysis of the hydropower potential of the periglacial Swiss Alps. The results are referenced to the Swiss Energy Strategy and other potential courses of action, such as upgrade of existing infrastructure. An evaluation matrix with 16 economical, environmental and social criteria for the consistent rating of all feasible sites is proposed. All criteria and their ratings are explained. It is demonstrated that the chosen methodology leads to a relatively stable ranking even for significantly different weighting models. Although being affected by uncertainties and remaining challenges, the methodology and results are sufficiently detailed for decision-making. Therefore, recommendations for future hydropower investments can be given. The results are strongly linked to Swiss boundary conditions, but the methodology itself is generally applicable for all glaciers worldwide, if the required input data are available
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