72 research outputs found

    Challenges in network science: Applications to infrastructures, climate, social systems and economics

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    [Ascending aortic and pulmonary trunk aneurysms]

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    A case of two non-atherosclerotic aneurysms localised in the ascending aorta and in the pulmonary trunk is presented. Histopathologically, a severe granulomatous inflammation affecting the whole aneurysms wall was documented. To the best of our knowledge it is the second ever documented case of simultaneous occurrence of aneurysms in the aorta and the pulmonary artery

    Magnesium silicide TEGs as self-sufficient power supply for smart systems

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    Thermoelectric generators (TEGs) can be used as a self-sufficient power supply. Thereby, the application in smart systems is promising because of the large number of sensors which often also have a low power consumption. To ensure cost effective TEGs a mass producible cold pressed process was developed for Mg2Si. By adapting the process set-up, the sintering temperature and the process atmosphere, densities of spark plasma sintering materials were almost reached

    Anodized aluminum as effective and cheap alternative substrate for thermoelectric generators

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    The wide usage of thermoelectric generators (TEG) is still blocked by very high product costs. This paper presents anodized aluminum (Al) as an effective and cheap alternative for ceramics like alumina (Al2O3) or aluminum nitride (AlN). Al has a significantly higher thermal conductivity as both named ceramics. In addition, the lower thermal stability of Al is still high enough to work with bismuth telluride based modules, which are most common. To show the advantages of the changed substrate, finite element method (FEM) simulations were performed. These simulations show that by changing the cold side substrate material the temperature drop across the substrate is reduced by 60 K. This correlates to a theoretical power gain of more than 20 %. Furthermore, Al can be shaped much easier than a ceramic material. The biggest advantage is obviously the price. Anodized Al is around twenty times cheaper than Al2O3. To demonstrate the easy fabrication of the proposed substrate, samples were prepared only with widely used processes like those used for conventional printed circuit boards

    Efficacy and Safety of Heparinization before Deployment of Endograft for Blunt Traumatic Aortic Injury in Severely Injured Patients

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    Background: The administration of unfractionated heparin (UFH) during endovascular repair of blunt traumatic aortic injury (BTAI) is controversial. The aim of the study is to report the early outcomes of patients undergoing thoracic endovascular aortic repair (TEVAR) for BTAI, and to assess the individualized intraoperative use and dose of UFH. Methods: This is a retrospective analysis including consecutive patients treated with TEVAR for BTAI of the descending aorta between January 1st, 2005 and December 31st, 2018. Intraoperative use and doses of UFH were analyzed. Primary outcome included a reintervention because of new onset bleeding and/or thromboembolic complication and 30-day mortality. Technical success, injury severity score (ISS), timing of treatment, and neurologic deterioration were secondary outcome. Results: Thirty-six patients with a mean age of 47 ± 18 years, 30 males (83%), were included. Intraoperative administration of UFH was recorded in 30/36 patients (83%) with a mean dose of 4750 ± 2180 IU. Two patients had no UFH because of extensive intracranial hemorrhage or suspected relevant liver laceration, respectively; 1 died in theatre, 1 was already anticoagulated having a mechanical aortic valve, and in 2 no information about heparin use was found. During 30 days of follow-up, 3 patients died (8%; 3/36): 1 patient with completely transected aorta died on-table and 2 on the fifth postoperative day, 1 from trauma-associated brain injury and 1 with multi organ failure. No bleeding or thromboembolic complication requiring reintervention occurred in any patient during 30 days follow-up. In 3 patients partial unintentional coverage of the left common carotid artery occurred, resulting in technical success of 89% (32/36). Mean ISS was 43 ± 15. Thirty-five patients (97%) were severely injured having an ISS ≥ 25. Twenty-nine patients (81%) were treated within 24 hr and 6 patients (17%) within 1 week. No stroke or spinal cord ischemia was observed. Conclusions: Systemic heparinization in different doses during TEVAR for BTAI can be safe with no intraoperative bleeding or thromboembolic complications in early postoperative period. © 202
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