374 research outputs found

    TWO CASES OF NON-ALCOHOLIC WERNICKE ENCEPHALOPATHY SUCCESSFULLY TREATED BY THIAMINE REPLACEMENT: DIAGNOSTIC AND THERAPEUTIC CONSIDERATIONS

    Get PDF
    Wernicke\u2019s encephalopathy (WE) is an acute neurologi- cal disorder, due to a lack of thiamin (vitamin B1) which is observed mainly in alcoholic patients. Unfortunately, the syn- drome is underestimated in clinical practice and most often recognized only on autopsy, especially among non-alcoholics. The common clinical picture include mental status changes, ocular dysfunction, and gait ataxia. Treatment consists of timely thiamine replacement through intravenous infusion. We describe the case of two patients who developed a non-alcoholic WE post-surgical, regressed completely after intravenous infusion of thiamine. These cases suggest intere- sting diagnostic and therapeutic implications

    ODEF: an interactive tool for optimized design of EMI filters

    Get PDF
    The impact of EMI filters on volume and weight of power converters is significant. For this reason, filter’s size optimization is a strategic step towards the improvement of the power converter’s power density. An EMI filter design that follows a conventional procedure does not guarantee the selection of components/configuration leading to the best power density. Therefore, in order to help EMI engineers and scientists in pursuing a fast and effective choice of optimal discrete EMI filter components and configuration, a novel tool is proposed in this paper, namely ODEF (Optimized Design of EMI Filters). ODEF is an interactive software application running in Matlab® environment. It suitably improves a previously validated EMI filter design procedure that extends the conventional filter design method in order to achieve optimal power density. Features and operation of ODEF tool are illustrated. Moreover, the experimental assessment of an input EMI filter, designed according to the optimized procedure for an inverter-fed induction motor drive, is performed

    Role of endocannabinoids and TRPV1 channels in the bioelectric activity of hippocampal neurons

    Get PDF
    It has been reported that endocannabinoid system is an important player in the regulation of neuronal bioelectrical activity, relying on receptor-mediated mechanisms. Amongst these, Cannabinoid receptor type 1 (CB1r) and Transient Receptor Potential Vanilloid type 1 (TRPV1) are both modulated by endocannabinoids, involved in the transduction of stimuli in the pre-synaptic neuron and prompt downstream pathways in the post-synaptic neuron. To investigate the role of CB1r/TRPV1 interplay, we applied whole-cell patch clamp technique to visualize the eventual variations in terms of membrane current and action potentials induced by pharmacological manipulation in rat hippocampal neurons. We modulated the activity of the CB1r and TRPV1 exploiting anandamide (AEA), CB1r and TRPV1 agonist, capsaicin (CAP), a TRPV1 agonist and capsazepine (CPZ), a TRPV1 antagonist. Our data show that AEA influences steady membrane current with respect to controls. Furthermore, drug application significantly modifies action potentials amplitude, duration and frequency. In particular, the co-treatment of AEA and CPZ increases the amplitude of action potentials, reduces their duration and thus increases their frequency. These preliminary results support the involvement of TRPV1 in the cannabinoid modulation of the bioelectrical activity in rat hippocampal neurons. Indeed, the concurrent blockade of these channels and activation of CBr influences basic properties of neuronal function

    Optimized design of high power density EMI filters for power electronic converters

    Get PDF
    Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance and size reduction, by a comparison between an EMI filter designed using the optimized procedure and a conventionally designed one, for two different case studies

    Design and Performance Evaluation of a High Power-Density EMI Filter for PWM Inverter-Fed Induction-Motor Drives

    Get PDF
    This paper presents the design of an electromagnetic interference (EMI) filter for a low-voltage high-current induction-motor drives supplied by dc power grids. In order to effectively design the EMI filter, a suitable common-mode/differential-mode (CM/DM) separation technique has been used. Due to the high operating currents, the software-based separation technique using time-domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e., without the need of a dedicated hardware or costly radio frequency (RF) instrumentation. The design has been done according to a power-density criterion. The effectiveness of the proposed CM/DM separation technique and the EMI filter features/performance has been assessed by experimental tests, carried out with an 1.1-kW pulsewidth modulation (PWM) inverter-fed induction-motor drive, supplied by a 48-V dc power grid

    Computer aided optimal design of high power density EMI filters

    Get PDF
    Power density of power converter systems is becoming an increasing crucial design constraint for a wide range of technical applications. Size reduction of EMI filter in power converters is an important challenge due to its significant impact on the overall converter volume and weight. In order to take on this issue, a computer aided procedure for a fast selection of optimal discrete EMI filter components and layout is described in this paper. The proposed technique is a rule-based automatic procedure based on a suitable database that considers the commercially available data sheets of passive components (e.g. magnetic cores, capacitors). It allows the minimization of the filter’s volume and therefore the improvement of the converter’s power density. The size and the performance of an EMI filter designed by using the proposed procedure, have been compared with those of a conventionally designed one. The comparison demonstrates the effectiveness of the proposed method

    The inhomogeneous mechanical behaviour of Ascending Thoracic Aortic Aneurism (ATAA)

    Get PDF
    Surgical management of ascending thoracic aortic aneurysms (aTAAs) relies on maximum diameter, growth rate, and presence of connective tissue disorders. The surgical decision however is often not considering that dissection and rupture do occur in patients who do not meet criteria for surgical repair [1,2]. In this study the authors aim to investigate the mechanical properties of aTAAs to be implemented in computational biomechanics models for a preclinical risk evaluation. Additionally, in some recent studies, some data about the biomechanical properties of the aTAAs have been reported [3], but without any relation to bicuspidal or tricuspidal aTAA. The aim of this study was to investigate aTAA mechanical properties using a biaxial system to compare the circumferential and axial stress-strain relations for bicuspidal and tricuspidal aTAAs

    FILTRI EMI COMPATTI NEI CONVERTITORI ELETTRONICI DI POTENZA

    Get PDF
    The goal of the research recently started is to create efficient EMI filters compact that allow to obtain converters with low dimensions and economically competitive

    Evaluation of trace calls by Xpert MTB/RIF ultra for clinical management in low TB burden settings

    Get PDF
    Background Clinical interpretation of trace results by Xpert MTB/RIF Ultra assay (Ultra) used as an initial diagnostic test for tuberculosis (TB) may be challenging. The aim of the study was to evaluate the frequency and epidemiology of trace readouts in routine clinical practice in a low TB prevalence setting and to propose guidance on how to manage patients with trace calls considering the data available (clinical, radiological, bacteriological etc.). Materials and methods A retrospective, observational, monocentric study was conducted at IRCCS Azienda Ospedaliero-Universitaria of Bologna, Italy between November 2017—December 2020. Presumptive TB patients with at least one Ultra trace result during diagnostic workup before treatment were included in the study. Patients with ongoing anti-TB treatment at the time of the trace call result or with no clinical data available were excluded from the study. Results Fifty-nine presumptive TB patients with Ultra trace readouts were included in the study (mean age 37.0 years, 61% males). Four patients had a history of TB in the last 2 years. Twenty-five (42.4%) of the 59 samples with trace results were respiratory material. 57/59 (96.6%) patients started anti-TB treatment soon after obtaining trace results, based on clinical, radiological or other information available, while for two patients with a recent history of TB the trace result did not lead to anti-TB treatment. Culture was positive for M. tuberculosis for 31/59 (52.5%) samples with trace calls: 13/25 (52.0%) were respiratory samples and 18/33 (54.5%) non-respiratory samples. The clinical and/or radiological findings of 47/57 (82.4%) patients given anti-TB therapy improved during treatment. Conclusion In low TB incidence settings, Ultra trace calls in presumptive TB patients should be considered as true-positive and treatment should be started promptly, except in cases of recent history of TB, where careful evaluation of other diagnostic criteria is necessary before starting anti-TB treatment. A decisional algorithm for clinical management is proposed

    PROGETTAZIONE OTTIMIZZATA DI FILTRI EMI AD ELEVATA POWER DENSITY PER CONVERTITORI ELETTRONICI DI POTENZA

    Get PDF
    In molti dei campi di impiego dei convertitori elettronici di potenza (aeronautico, aerospaziale, automotive, etc.) è richiesta la realizzazione di sistemi di conversione che, in relazione a stringenti vincoli di progetto, presentino, a parità di potenza, dimensioni sempre più compatte e pesi ridotti. In tale ottica, l’ottimizzazione della densità di potenza (power density) del convertitore diventa un obiettivo essenzial
    • …
    corecore