29 research outputs found

    Classification Scheme of Heating Risk during MRI Scans on Patients with Orthopaedic Prostheses

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    Due to the large variety of possible clinical scenarios, a reliable heating-risk assessment is not straightforward when patients with arthroplasty undergo MRI scans. This paper proposes a simple procedure to estimate the thermal effects induced in patients with hip, knee, or shoulder arthroplasty during MRI exams. The most representative clinical scenarios were identified by a preliminary frequency analysis, based on clinical service databases, collecting MRI exams of 11,658 implant carrier patients. The thermal effects produced by radiofrequency and switching gradient fields were investigated through 588 numerical simulations performed on an ASTM-like phantom, considering four prostheses, two static field values, seven MR sequences, and seven regions of imaging. The risk assessment was inspired by standards for radiofrequency fields and by scientific studies for gradient fields. Three risk tiers were defined for the radiofrequency, in terms of whole-body and local SAR averages, and for GC fields, in terms of temperature elevation. Only 50 out of 588 scenarios require some caution to be managed. Results showed that the whole-body SAR is not a self-reliant safety parameter for patients with metallic implants. The proposed numerical procedure can be easily extended to any other scenario, including the use of detailed anatomical models

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Recovering the Jiu Qu River, Urban Renewal Project in Zhongshan

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    Il disseppellimento di un antico fiume che attraversava il centro della città di Zhongshan in Cina è il singolare esperimento di cui si scrive in questo libro. E' il frutto di una collaborazione tra le Scuole Universitarie di Architettura di Venezia, Ascoli e Pescara con l'Istituto di Pianificazione di Zhongshan. Il recupero delle preesistenze architettoniche - desunto dalle esperienze italiane - viene integrato da interventi di riqualificazione delle sponde del fiume e di nuove costruzioni per restituire valore e vitalità all'antico centro della citt

    Charge selectivity of proteinuria in type 1 diabetes explored by immunoglobulin subclass clearance

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    To investigate the role of protein charge in early diabetic proteinuria, the clearance of proteins differing in charge and/or size (anionic and cationic Igs, albumin) was evaluated in 98 insulin-dependent (type I) diabetic patients selected as a representative sample of the 418 patients attending our clinics. Of the patients, 12.9% were microalbuminuric and 4.8% were macroalbuminuric. Anionic and total IgG clearances were significantly increased in 30.6 and 12.2% of patients and were correlated with duration of disease. Anionic IgG4 clearances were increased in patients (9.2%) with normal IgG excretion, suggesting that charge-selectivity impairment is responsible for protein loss. Anionic Ig clearances were also higher in some patients (14.3%) with normal albumin clearance, probably as a result of different glomerular filtration and/or tubular reabsorption. The anionic-cationic IgG clearance ratio tended to increase in parallel with albumin clearance, but once above macroalbuminuric levels, it tended to fall again, indicating the concomitant presence of size-selectivity loss. The anionic IgG clearance and the anionic-cationic IgG ratio, in addition to albumin excretion, may be valuable in assessing early kidney protein charge-selectivity impairment and better characterizing normoalbuminuric patients and those in the preclinical stage of diabetic nephropathy
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