444 research outputs found

    Intraluminal recanalization of long infrainguinal chronic total occlusions using the Crosser system

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    Purpose: To assess the safety and efficacy of a device for vibrational angioplasty in the percutaneous intraluminal recanalization of long infrainguinal chronic total occlusions (CTO). Technique: The Crosser CTO Recanalization System is a mechanical recanalization device that uses high-frequency vibrational energy to disrupt and channel through fibrocalcific plaque without harming the vessel wall, thus assisting in the recanalization of an occluded artery. In 12 diabetic patients (7 men; median age 71 years, range 58–80) with critical limb ischemia owing to long (median length 26 cm, range 21–32) infrainguinal CTOs resistant to conventional guidewire techniques, the Crosser CTO Recanalization System was successful in intraluminally crossing the occlusion in 9 (75%) patients in ,5 minutes (mean 4:03 minutes). The safety endpoint (distal lumen guidewire position with no vessel perforation or dissection) was achieved in all successful cases. Conclusion: In our preliminary experience, the Crosser CTO Recanalization Catheter decreased crossing time, was safe, and achieved a high rate of intraluminal recanalization of long infrainguinal CTOs. J Endovasc Ther. 2009;16:23–27 Key words: critical limb ischemia, chronic total occlusion, percutaneous interventions, infrainguinal occlusion, intraluminal recanalization, vibrational energ

    Chronic Contained Rupture of an Abdominal Aortic Aneurysm: From Diagnosis to Endovascular Resolution

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    A male patient, 69 years old, presented with fever, leucocytosis, and persistent low back pain; he also had an abdominal aortic aneurysm (AAA), as previously diagnosed by Doppler UltraSound (US), and was admitted to our hospital. On multislice computed tomography (msCT), a large abdominal mass having no definite border and involving the aorta and both of the psoas muscles was seen. This mass involved the forth-lumbar vertebra with lysis, thus simulating AAA rupture into a paraspinal collection; it was initially considered a paraspinal abscess. After magnetic resonance imaging examination and culture of the fluid aspirated from the mass, no infective organisms were found; therefore, a diagnosisof chronically contained AAA rupture was made, and an aortic endoprosthesis was subsequently implanted. The patient was discharged with decreased lumbar pain. At 12-month follow-up, no evidence of leakage was observed. To our knowledge, this is the first case of endoprosthesis implantation in a patient, who was a poor candidate for surgical intervention due to renal failure, leucocytosis and high fever, having a chronically contained AAA ruptured simulatingspodilodiscitis abscess. Appropriate diagnosis and therapy resolved potentially crippling pathology and avoided surgical graftrelated complications. Keywords Abdominal aortic aneurysm Endoprosthesis implantation Vertebral erosio

    Life cycle assessment of the biofuel production from lignocellulosic biomass in a hydrothermal liquefaction - aqueous phase reforming integrated biorefinery

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    The use of biofuels in the transport sector is one of the strategies for its decarbonization. Here, the LCA meth-odology was used for the first time to assess the environmental impacts of a biorefinery where hydrothermal liquefaction (HTL) and aqueous phase reforming (APR) were integrated. This novel coupling was proposed to valorize the carbon loss in the HTL-derived aqueous phase, while simultaneously reducing the external H2 de-mand during biocrude upgrading. Corn stover (residue) and lignin-rich stream (waste) were evaluated as possible lignocellulosic feedstocks. The global warming potential (GWP) was 56.1 and 58.4 g CO2 eq/MJbiofuel, respec-tively. Most of the GWP was attributable to the electrolysis step in the lignin-rich stream case and to the thermal duty and platinum use in the corn stover case. Other impact categories were investigated, and an uncertainty analysis was also carried out. A sensitivity analysis on biogenic carbon, electricity/thermal energy source and alternative hydrogen supply was conducted to estimate their influence on the GWP. Finally, the two scenarios were compared with the environmental impact of fossil-and other biomass-derived fuels, also considering fuel utilization. HTL-APR allowed a 37% reduction compared to fossil diesel, further reduced to 80% with the lignin -rich stream when green energy was used

    THE MAIN PORTAL OF THE CATHEDRAL OF MONREALE: FIRST GEOMETRIC ANALYSIS AND INTERPRETIVE ASSESSMENT OF ARCHITECTURAL FEATURES

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    Nowadays, 3D documentation of architectural assets is becoming a demanding task for the valorisation of Cultural Heritage especially after a restoration project. The 3D documentation can be used for detailed analysis of specific elements, for monitoring the state of conservation and for valorisation actions. The paper describes the results of the 3D close-range photogrammetry survey of the main portal of the Cathedral of Monreale (Palermo, Italy). The Cathedral is one the most important monumental complexes in Sicily that, for its high historical and artistic importance has been inscribed on UNESCO\u2019s World Heritage List since 2015. The main portal of the Cathedral has been recently restored. The restoration work has given the opportunity to evidence small details of the sculptural decorations and to carry out new interpretative analysis of the bas-reliefs. The main purpose of the work is to obtain a detailed 3D model and a high-resolution ortophoto of the entire portal and of some architectural details. The study was used to evaluate the most appropriate technical solutions for the 3D survey and to define the most suitable parameters for image acquisition and data processing

    Moral Mediators in the Metaverse: Exploring Artificial Morality through a Talking Cricket Paradigm

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    As technological innovations continue to shape our social interactions, the Metaverse introduces immersive experiences that reflect real-life practices, accessible by users through their avatars. However, these interactions also bring forth potential negative aspects, including discrimination and cyberbullying. While current automatic detection systems exist, educating users on appropriate behaviour remains crucial. Leveraging recent advancements in Artificial Intelligence, the paper focuses on creating virtual AI-controlled moral agents within the Metaverse to guide users in dealing with moral dilemmas. The research aims to understand how such agents impact users' perceptions and behaviours in ethically challenging virtual environments

    Aqueous phase reforming of pilot-scale Fischer-Tropsch water effluent for sustainable hydrogen production

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    Fischer-Tropsch (FT) synthesis produces an aqueous stream containing light oxygenates as major by-product. The low carbon concentration of the organics makes its thermal recovery unprofitable. Thus, novel processes are needed to utilize this waste carbon content. In this work, the aqueous phase reforming of the wastewater obtained from a 15 kWth Fischer-Tropsch plant was explored as a promising process to produce hydrogen at mild temperatures. The FT product water was firstly characterized and afterward subjected to the reforming at different reaction temperatures and time, using a platinum catalyst supported on activated carbon. It was observed that, besides activity, the selectivity towards hydrogen was favored at higher temperatures; equally, increasing the reaction time allowed to obtain the total conversion of most molecules found in the solution, without decreasing the selectivity and reaching a plateau at 4 hours in the hydrogen productivity. In order to get more insights into the reaction mechanism and product distribution derived from the APR of FT product water, several tests were performed with single compounds, finding characteristic features. The importance of the position of the hydroxyl group in the molecule structure was highlighted, with secondary alcohols more prone to dehydrogenation pathways compared to primary alcohols. Moreover, no interference among the substrates was reported despite the mixture is constituted by several molecules: in fact, the results obtained with the real FT product water were analogous to the linear combination of the single compound tests. Finally, the reuse of the catalyst showed no appreciable deactivation phenomena

    Aqueous phase reforming of the residual waters derived from lignin-rich hydrothermal liquefaction: investigation of representative organic compounds and actual biorefinery streams

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    Secondary streams in biorefineries need to be valorized to improve the economic and environmental sustainability of the plants. Representative model compounds of the water fraction from the hydrothermal liquefaction (HTL) of biomass were subjected to aqueous phase reforming (APR) to produce hydrogen. Carboxylic and bicarboxylic acids, hydroxyacids, alcohols, cycloketones and aromatics were identified as model compounds and tested for APR. The tests were performed with a Pt/C catalyst and the influence of the carbon concentration (0.3–1.8 wt. C%) was investigated. Typically, the increase of the concentration negatively affected the conversion of the feed toward gaseous products, without influencing the selectivity toward hydrogen production. A synthetic ternary mixture (glycolic acid, acetic acid, lactic acid) was subjected to APR to evaluate any differences in performance compared to the tests with single compounds. Indeed, glycolic acid reacted faster in the mixture than in the corresponding single compound test, while acetic acid remained almost unconverted. The influence of the reaction time, temperature and carbon concentration was also evaluated. Finally, residual water resulting from the HTL of a lignin-rich stream originating from an industrial-scale lignocellulosic ethanol process was tested for the first time, after a thorough characterization. In this framework, the stability of the catalyst was studied and found to be correlated to the presence of aromatics in the aqueous feedstock. For this reason, the influence of an extraction procedure for the selective removal of these compounds was explored, leading to an improvement in the APR performance
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