25 research outputs found

    Analisi Numerica di una Bobina a Radiofrequenza per Applicazione di Risonanza Magnetica Articolare

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    Il presente lavoro di tesi ù il risultato della collaborazione tra l’Istituto di Fisiologia Clinica del CNR di Pisa e l’azienda Paramed Medical System di Genova. E’ stata utilizzata una bobina commerciale dalla geometria complessa per scanner a basso campo per indagine del ginocchio realizzata dalla Paramed. Parallelamente alle prove al banco sono state effettuate simulazioni numeriche grazie al software Remcom XFDTD e sono state calcolate la resistenza indotta dal campione, le mappe di sensitività e l’omogeneità di campo magnetico generato e i parametri di disaccoppiamento. Il capitolo 1 sarà diviso in due parti: una prima che si proporrà di descrivere i principi fisici alla base della risonanza magnetica; una seconda che descriverà i componenti di in comune scanner di risonanza con particolare attenzione ai diversi tipi di bobine. Il capitolo 2 introdurrà i principali metodi numerici e si soffermerà sulla descrizione del metodo alle differenze finite (FDTD) alla base del software XFDTD da noi utilizzato. Nel capitolo 3 verrà fatta un descrizione dei vari materiali e delle metodiche usate: a partire dallo sviluppo in XFDTD del nostro modello, fino all’uso anche del software Matlab per l’analisi dei dati forniti dalla simulazione. Il capitolo 4 mostrerà i risultati ottenuti sia con i software sia a seguito delle prove al banco allo scopo di confrontare i dati e valutare una correlazione tra le due metodiche. Infine, l’ultimo capitolo, conterrà una discussione conclusiva sui risultati mostrati nel capitolo precedente e una riflessione in base agli obbiettivi prefissati all’inizio di questo lavoro

    Analyzing the interaction between the reader's voice and the linguistic structure of the text: a preliminary study

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    In this study, we present a preliminary analysis of the relationship between the linguistic profile of a text and the voice properties of the reader aiming to improve the speech-based emotion recognition systems. To this aim, we recorded the speech signals from a group of 32 healthy volunteers reading aloud neutral and affective texts and used the BioVoice toolbox to compute some of the main speech features. The selected texts were analyzed to quantify their lexical, morpho-syntactic, and syntactic content. Correlation and Support Vector Regressor analyses between linguistic and speech features have shown a significant modulation of some voice acoustic properties performed by the linguistic structure of the text. Particularly, a significant effect was shown on some specific speech features often used for the assessment of human emotional state (e.g., F0). This suggests that the lexical, morpho-syntactic, and syntactic properties could play an important role in the emotional dynamics of a person

    The value of some Corsican sub-populations for genetic association studies

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    <p>Abstract</p> <p>Background</p> <p>Genetic isolates with a history of a small founder population, long-lasting isolation and population bottlenecks represent exceptional resources in the identification of disease genes. In these populations the disease allele reveals Linkage Disequilibrium (LD) with markers over significant genetic intervals, therefore facilitating disease locus identification. In a previous study we examined the LD extension on the Xq13 region in three Corsican sub-populations from the inner mountainous region of the island. On the basis of those previous results we have proposed a multistep procedure to carry out studies aimed at the identification of genes involved in complex diseases in Corsica. A prerequisite to carry out the proposed multi-step procedure was the presence of different degrees of LD on the island and a common genetic derivation of the different Corsican sub-populations. In order to evaluate the existence of these conditions in the present paper we extended the analysis to the Corsican coastal populations.</p> <p>Methods</p> <p>Samples were analyzed using seven dinucleotide microsatellite markers on chromosome Xq13-21: DXS983, DXS986, DXS8092, DXS8082, DXS1225, DXS8037 and DXS995 spanning approximately 4.0 cM (13.3 Mb). We have also investigated the distribution of the DXS1225-DXS8082 haplotype which has been recently proposed as a good marker of population genetic history due to its low recombination rate.</p> <p>Results</p> <p>the results obtained indicate a decrease of LD on the island from the central mountainous toward the coastal sub-populations. In addition the analysis of the DXS1225-DXS8082 haplotype revealed: 1) the presence of a particular haplotype with high frequency; 2) the derivation from a common genetic pool of the sub-populations examined in the present study.</p> <p>Conclusion</p> <p>These results indicate the Corsican sub-populations useful for the fine mapping of genes contributing to complex diseases.</p

    Molecularly Imprinted Polymers: Present and Future Prospective

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    Molecular Imprinting Technology (MIT) is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs), the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented

    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

    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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    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

    Numerical Analysis of Electromagnetic Field Exposure from 5G Mobile Communications at 28 GHZ in Adults and Children Users for Real-World Exposure Scenarios

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    The recent development of millimeter-wave (mmW) technologies, such as the fifth-generation (5G) network, comes with concerns related to user exposure. A quite large number of dosimetry studies above 6 GHz have been conducted, with the main purpose being to establish the correlation between different dosimetric parameters and the skin surface temperature elevation. However, the dosimetric studies from 28 GHz user equipment using different voxel models have not been comprehensively discussed yet. In this study, we used the finite-difference time-domain (FDTD) method for the estimation of the absorption of radiofrequency (RF) energy from a microstrip patch antenna array (28 GHz) in different human models. Specifically, we analyzed different exposure conditions simulating three real common scenarios (a phone call scenario, message writing scenario, and browsing scenario) regarding the use of smartphones/tablets by four different individuals (adult male and female, child male and female). From the results of Absorbed Power Density (Sab), it is possible to conclude that all the considered exposure scenarios comply with the safety limits, both for adult and children models. However, the high values of the local Specific Absorption Rate (SAR) in the superficial tissues and the slight differences in its distribution between adults and children suggest the need for further and more detailed analysis

    Numerical evaluation of human exposure to WiMax patch antenna in tablet or laptop

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    The use of wireless communication devices, such as tablets or laptops, is increasing among children. Only a few studies assess specific energy absorption rate (SAR) due to exposure from wireless-enabled tablets and laptops, in particular with Worldwide Interoperability for Microwave Access (WiMax) technology. This paper reports the estimation of the interaction between an E-shaped patch antenna (3.5 GHz) and human models, by means of finite-difference time-domain (FDTD) method. Specifically, four different human models (young adult male, young adult female, pre-teenager female, male child) in different exposure conditions (antenna at different distances from the human model, in different positions, and orientations) were considered and whole-body, 10 and 1 g local SAR and magnetic field value (Bmax) were evaluated. From our results, in some worst-case scenarios involving male and female children's exposure, the maximum radiofrequency energy absorption (hot spots) is located in more sensitive organs such as eye, genitals, and breast. Bioelectromagnetics. 39:414–422, 2018. © 2018 Wiley Periodicals, Inc
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