382 research outputs found

    Microscopic Polyangiitis With Selective Involvement of Central and Peripheral Nervous System : A Case Report

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    Background: Microscopic polyangiitis (MPA) is a necrotizing vasculitis that affects predominantly small-sized vessels in many organ systems. The disease generally causes glomerulonephritis, pulmonary damage, arthritis, and neuropathy. An exclusive involvement of both central nervous system (CNS) and peripheral nervous system (PNS) is extremely rare. Case Presentation: A 62-year-old woman was admitted to our hospital with a 3 months history of right foot drop, recently complicated by intense myalgia, arthralgia, and allodynia to tactile, vibratory, and pressure stimuli. Since blood tests revealed elevated inflammatory indexes, we suspected either infectious or immune-mediated disorders. Chest radiograph, blood culture series, and echocardiogram revealed normal findings, while urinalysis showed a bacterial infection that was successfully treated. The neurophysiological findings were compatible with multiple mononeuritis, and a brain MRI evidenced ischemic lesions of both basal ganglia and thalamus. A wide-spectrum autoantibody assay revealed the presence of high-titer perinuclear anti-neutrophil cytoplasmic antibodies specific for myeloperoxidase (MPO-ANCA). According to these findings, the diagnosis of MPA was made, and the patient was successfully treated with intravenous (IV) methylprednisolone, followed by two doses of rituximab. Conclusions: An assessment of both CNS and PNS should be included in the diagnostic evaluation of MPA. The involvement of the PNS may raise the risk of a relapsing course and treatment failure, therefore it should be considered in the choice of induction and maintenance therapy

    Structure-dependent optical and electrical transport properties of nanostructured Al-doped ZnO

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    The structure-property relation of nanostructured Al-doped ZnO thin films has been investigated in detail through a systematic variation of structure and morphology, with particular emphasis on how they affect optical and electrical properties. A variety of structures, ranging from compact polycristalline films to mesoporous, hierarchically organized cluster assemblies, are grown by Pulsed Laser Deposition at room temperature at different oxygen pressures. We investigate the dependence of functional properties on structure and morphology and show how the correlation between electrical and optical properties can be studied to evaluate energy gap, conduction band effective mass and transport mechanisms. Understanding these properties opens the way for specific applications in photovoltaic devices, where optimized combinations of conductivity, transparency and light scattering are required.Comment: 8 pages, 9 figure

    Hierarchical TiN-Supported TsFDH Nanobiocatalyst for CO2 Reduction to Formate

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    The electrochemical reduction of CO2 to value-added products like formate represents a promising technology for the valorization of carbon dioxide. We propose a proof-of-concept bioelectrochemical system (BES) for the reduction of CO2 to formate. For the first time, our device employs a nanostructured titanium nitride (TiN) support for the immobilization of a formate dehydrogenase (FDH) enzyme. The hierarchical TiN nanostructured support exhibits high surface area and wide pore size distribution, achieving high catalytic loading, and is characterized by higher conductivity than other oxide-based supports employed for FDHs immobilization. We select the oxygen-tolerant FDH from Thiobacillus sp. KNK65MA (TsFDH) as enzymatic catalyst, which selectively reduces CO2 to formate. We identify an optimal TiN morphology for the enzyme immobilisation through enzymatic assay, reaching a catalyst loading of 59 mu g cm(-2) of specifically-adsorbed TsFDH and achieving a complete saturation of the anchoring sites available on the surface. We evaluate the electrochemical CO2 reduction performance of the TiN/TsFDH system, achieving a remarkable HCOO- Faradaic efficiency up to 76 %, a maximum formate yield of 44.1 mu mol mg(FDH)(-1) h(-1) and high stability. Our results show the technological feasibility of BES devices employing novel, nanostructured TiN-based supports, representing an important step in the optimization of these devices

    Hierarchical TiN-Supported TsFDH Nanobiocatalyst for CO2 Reduction to Formate

    Get PDF
    The electrochemical reduction of CO2 to value-added products like formate represents a promising technology for the valorization of carbon dioxide. We propose a proof-of-concept bioelectrochemical system (BES) for the reduction of CO2 to formate. For the first time, our device employs a nanostructured titanium nitride (TiN) support for the immobilization of a formate dehydrogenase (FDH) enzyme. The hierarchical TiN nanostructured support exhibits high surface area and wide pore size distribution, achieving high catalytic loading, and is characterized by higher conductivity than other oxide-based supports employed for FDHs immobilization. We select the oxygen-tolerant FDH from Thiobacillus sp. KNK65MA (TsFDH) as enzymatic catalyst, which selectively reduces CO2 to formate. We identify an optimal TiN morphology for the enzyme immobilisation through enzymatic assay, reaching a catalyst loading of 59 μg cm−2 of specifically-adsorbed TsFDH and achieving a complete saturation of the anchoring sites available on the surface. We evaluate the electrochemical CO2 reduction performance of the TiN/TsFDH system, achieving a remarkable HCOO− Faradaic efficiency up to 76 %, a maximum formate yield of 44.1 μmol mg−1FDH h−1 and high stability. Our results show the technological feasibility of BES devices employing novel, nanostructured TiN-based supports, representing an important step in the optimization of these devices

    Hierarchically organized nanostructured TiO2 for photocatalysis applications

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    A template-free process for the synthesis of nanocrystalline TiO2 hierarchical microstructures by reactive Pulsed Laser Deposition (PLD) is here presented. By a proper choice of deposition parameters a fine control over the morphology of TiO2 microstructures is demonstrated, going from classical compact/columnar films to a dense forest of distinct hierarchical assemblies of ultrafine nanoparticles (<10 nm), up to a more disordered, aerogel-type structure. Correspondingly, film density varies with respect to bulk TiO2 anatase, with a degree of porosity going from 48% to over 90%. These structures are stable with respect to heat treatment at 400 centigrade degrees, which results in crystalline ordering but not in morphological changes down to the nanoscale. Both as deposited and annealed films exhibit very promising photocatalytic properties, even superior to standard Degussa P25 powder, as demonstrated by the degradation of stearic acid as a model molecule. The observed kinetics are correlated to the peculiar morphology of the PLD grown material. We show that the 3D multi-scale hierarchical morphology enhances reaction kinetics and creates an ideal environment for mass transport and photon absorption, maximizing the surface area-to-volume ratio while at the same time providing readily accessible porosity through the large inter-tree spaces that act as distributing channels. The reported strategy provides a versatile technique to fabricate high aspect ratio 3D titania microstuctures through a hierarchical assembly of ultrafine nanoparticles. Beyond photocatalytic and catalytic applications, this kind of material could be of interest for those applications where high surface-to-volume and efficient mass transport are required at the same time.Comment: 10 pages, 7 figures, Nanotechnology (accepted

    An Electrically Conductive Oleogel Paste for Edible Electronics

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    Edible electronics will facilitate point-of-care testing through safe devices digested/degraded in the body/environment after performing a specific function. This technology, to thrive, requires a library of materials that are the basic building blocks for eatable platforms. Edible electrical conductors fabricated with green methods and at a large scale and composed of food derivatives, ingestible in large amounts without risk for human health are needed. Here, conductive pastes made with materials with a high tolerable upper intake limit (≥mg kg−1 body weight per day) are proposed. Conductive oleogel composites, made with biodegradable and food-grade materials like natural waxes, oils, and activated carbon conductive fillers, are presented. The proposed pastes are compatible with manufacturing processes such as direct ink writing and thus are suitable for an industrial scale-up. These conductors are built without using solvents and with tunable electromechanical features and adhesion depending on the composition. They have antibacterial and hydrophobic properties so that they can be used in contact with food preventing contamination and preserving its organoleptic properties. As a proof-of-principle application, the edible conductive pastes are demonstrated to be effective edible contacts for food impedance analysis, to be integrated, for example, in smart fruit labels for ripening monitoring
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