177 research outputs found

    Synchronized Measurement System for Railway Application

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    In the light of the recent European directives that regulate railway networks in EU, in order to implement the monitoring and controlling of the railways power supply network, an accurate and reliable knowledge of the exchanged energy between the train and the railway grid is an essential task. Therefore, a measurement system for railway applications must accurately evaluate energy and power quality. In order to do this, the synchronization to a common time reference of all the measurement devices of the network is mandatory. In this paper, a flexible measurement instrument for analysing different types of signals that could be found in railway systems is presented. The proposed instrument has extreme flexibility about the nature of input signals and it implements a synchronization technique to the absolute time via Global Positioning System (GPS). The implementation of the measurement system, along with evaluation of synchronization accuracy, is discussed

    Power Quality Assessment in Railway Traction Supply Systems

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    The assessment of the power quality (PQ) could be a valuable tool to foster the efficiency of the railway systems. PQ is a well-addressed topic in conventional ac 50/60 Hz power systems, and many procedures, algorithms and measurement systems were presented in the international standards and widely discussed in the scientific literature. A less explored research field is the assessment of the PQ in the railway traction supply systems, in particular with reference to the dc and 16.7 Hz systems. The article explores this theme, proposing an extension of the definitions and of the standard measurement procedures for some of the main PQ indexes, well defined and widely used for conventional power systems, in order to be used also in all railway traction supply systems. The limits or difficulties of applicability are discussed with reference to measurements performed both on-board and in substation. The proposed procedures are applied to an experimental case of a real dc railway system with a large measurement campaign

    Early anti IL-1 treatment replaces steroids in refractory Kawasaki disease: clinical experience from two case reports

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    Refractory Kawasaki disease (KD) is related to a major risk of coronary arteries abnormalities and its treatment is not standardized. In this regard, anakinra (ANA), an interleukin (IL)-1 receptor antagonist, represents an emerging therapeutic option. We report two cases of children, diagnosed with KD, nonresponsive to two doses of intravenous immunoglobulins, successfully treated with ANA, without a prior use of steroids. Patient 2 developed a coronary dilatation, that improved significantly after ANA therapy. Our experience highlights IL-1 blockade effectiveness in reducing KD inflammation and suggests ANA adoption as second-line therapy, with a timesaving and steroid-sparing strategy. Our results, combined with the evidence of the IL-1 key role in KD and coronary arteritis pathogenesis and to the recent clinical evidence reported by the KAWAKINRA trial, encourage an earlier recourse to ANA in patients with refractory KD, in order to fight inflammation, and to treat and prevent the development of coronary artery aneurysms. Further studies are needed to better define the place of IL-1 blockade in KD step-up treatment

    Calibration System for DC Power/Energy Measurement chain in Railway applications

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    In order to guarantee the European interoperability of rolling stock, the European Union (EU) established that all the trains shall be equipped with an Energy Measurement Function (EMF) for billing purposes. The measurement accuracy of such devices should be assessed and periodically re-verified, as required by EN 50462-2. This paper describes a setup for the calibration of combined voltage and current transducers and EMFs for on-board Direct Current (DC) train installation. The reference system is able to generate an arbitrary DC phantom power up to 6 MW with voltage up to 5 kV and a current up to 1.2 kA. Furthermore, in order to perform tests as close as possible to real operating conditions, the system allows performing dynamic tests, reproducing waveforms obtained in real measurement campaigns. The computed uncertainty for steady state tests is 0.025%, whereas the target uncertainty for dynamic tests is 0.1%. The generation system can also be applied for on-board reverification of EMF

    Detection of SF3B1 p.Lys700Glu Mutation by PNA-PCR Clamping in Myelodysplastic Syndromes and Myeloproliferative Neoplasms

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    Mutations in SF3B1 are found in 20% of myelodysplastic syndromes and 5–10% of myeloproliferative neoplasms, where they are considered important for diagnosis and therapy decisions. Sanger sequencing and NGS are the currently available methods to identify SF3B1 mutations, but both are time-consuming and expensive techniques that are not practicable in most small-/medium-sized laboratories. To identify the most frequent SF3B1 mutation, p.Lys700Glu, we developed a novel fast and cheap assay based on PNA-PCR clamping. After setting the optimal PCR conditions, the limit of detection of PNA-PCR clamping was evaluated, and the method allowed up to 0.1% of mutated SF3B1 to be identified. Successively, PNA-PCR clamping and Sanger sequencing were used to blind test 90 DNA from patients affected by myelodysplastic syndromes and myeloproliferative neoplasms for the SF3B1 p.Lys700Glu mutation. PNA-PCR clamping and Sanger sequencing congruently identified 75 negative and 13 positive patients. Two patients identified as positive by PNA-PCR clamping were missed by Sanger analysis. The discordant samples were analyzed by NGS, which confirmed the PNA-PCR clamping result, indicating that these samples contained the SF3B1 p.Lys700Glu mutation. This approach could easily increase the characterization of myelodysplastic syndromes and myeloproliferative neoplasms in small-/medium-sized laboratories, and guide patients towards more appropriate therapy

    The use of virtual surgical planning and navigation in the treatment of orbital trauma

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    Virtual surgical planning (VSP) has recently been introduced in craniomaxillofacial surgery with the goal of improving efficiency and precision for complex surgical operations. Among many indications, VSP can also be applied for the treatment of congenital and acquired craniofacial defects, including orbital fractures. VSP permits the surgeon to visualize the complex anatomy of craniofacial region, showing the relationship between bone and neurovascular structures. It can be used to design and print using three-dimensional (3D) printing technology and customized surgical models. Additionally, intraoperative navigation may be useful as an aid in performing the surgery. Navigation is useful for both the surgical dissection as well as to confirm the placement of the implant. Navigation has been found to be especially useful for orbit and sinus surgery. The present paper reports a case describing the use of VSP and computerized navigation for the reconstruction of a large orbital floor defect with a custom implant

    Severe Corneal Morphological Alterations after Excimer Laser Surface Ablation for a High Astigmatism

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    We report long-term alterations of anterior corneal stroma after excimer laser surface ablation for a high astigmatism. The patient claimed progressive visual loss in his right eye (RE) during the last 3 years after bilateral laser-assisted subepithelial keratectomy (LASEK) surgery. His examination comprised visual acuity (UDVA and CDVA), slit-lamp examination, corneal topography and tomography, AS-OCT, and confocal microscopy. The UDVA was 0.1 in his RE and 1.0 in the left eye. The CDVA in the RE was 0.8. The slit-lamp examination showed a stromal lesion in the inferior paracentral corneal zone, with multiple vertical tissue bridges and severe thinning. Corneal topography and tomography showed central flattening with inferior steepening and severe alteration in elevation maps. AS-OCT showed void areas in the anterior stroma with thinning of the underlying tissue, and confocal images were not specific. In this case, progressive corneal steepening and thinning that manifest topographically as inferior ectasia occurred in correspondence to the singular stromal alterations after LASEK
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