76 research outputs found

    Microwave processing of high entropy alloys: A powder metallurgy approach

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    Microwaves at the ISM frequency of 2450 and 5800 MHz have been exploited to prepare FeCoNiCrAl-family high entropy alloys by direct heating of pressed mixtures of metal powders. The aim of this work is to explore a new microwave assisted near-net-shape technology, using powder metallurgy approach for the preparation of high entropy alloys, able to overcome the limits of current melting technologies (defects formation) or solid state ones (time demanding). Results show that direct microwave heating of the powder precursors occurs, and further heating generation is favored by the ignition of exothermal reactions in the compound. Microwave processing, exploited both for the ignition and sustaining of such reactions, has been compared to reactive sintering in laboratory furnace and mechanical alloying in a planetary ball milling. Results demonstrate that microwave required the shortest time and lowest energy consumption, thus it is promising time- and cost-saving synthetic route

    Lipoprotein glomerulopathy associated with a mutation in apolipoprotein e

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    Lipoprotein glomerulopathy is a pathological condition characterized by lipid accumulation in the glomerular capillaries that has been associated with the presence of rare mutants of apolipoprotein E (ApoE). We describe a 51-year-old Italian patient presenting Type III hyperlipidemia and proteinuria in whom renal biopsy showed capillary ectasia and intraluminal lipid deposits, suggesting the diagnosis of lipoprotein glomerulopathy. The patient, who had elevated plasma ApoE level, was found to be heterozygous for a mutation in ApoE (Arg150Cys), designated apoEMODENA. This mutation induces the formation of ApoE dimers that are detectable under non-reducing conditions. Treatment with hypolipidemic drugs did not result in a complete remission of the proteinuria and was accompanied by a slow but progressive worsening of renal function with the persistence of intracapillary lipid thrombi. The introduction of low-density lipoprotein aphaeresis combined with a more aggressive lipid lowering and antihypertensive therapy resulted in the remission of proteinuria and a substantial improvement of renal function. Switching from low-density lipoprotein aphaeresis to plasma filtration did not result in an equivalent control of renal damage. The patient died of intracranial hemorrhage during an acute episode of malignant hypertension

    Sustainable Chromium Encapsulation: Alkali Activation Route

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    This article highlights recent experimental advances in the use of inorganic substances in the encapsulation of pollutants and, in particular, discusses the potential applicability and constraints of the geopolymerization process for the treatment of wastewater containing chromium. A great percentage of waste containing chromium salts is produced by the leather industry during the tannery process. Such industrial waste is in the form of liquor containing almost 40% of the initial chromium combined with many other pollutants. The stabilization/solidification (S/S) treatment of this type of waste must be combined with chromium encapsulation in an economic, environmentally friendly and efficient process to be industrially feasible. Here we present a novel process in which the wastewater is used as a component of the formulation together with a clay by-product and with the addition of NaOH pellets with the goal of a no-water plus no-waste technology approach. The final solidified “ceramic-like” material successfully immobilized the heavy metal cations as well as anions and macromolecules of surfactants, avoiding environmental damages to soil and groundwater. The article is completed by mentioning other S/S processes where wastewater has been treated and the resulting sludge encapsulated. The future of the S/S technologies in the tannery industry should progress in the direction of significantly reducing the amount of wastewater directed to the treatment plants, with associated reductions in transport and their CO2 emissions. This article intends to be a contribution in the direction of preventing waste, aligning circular economy and waste management objectives

    Pair distribution function analysis and Mössbauer study of defects in microwave-hydrothermal LiFePO 4

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    Olivine-type LiFePO 4 is nowadays one of the most important cathode materials of choice for high-energy lithium ion batteries. Its intrinsic defectivity, and chiefly the so-called lithium iron anti-site, is one of the most critical issues when envisaging electrochemical applications. This paper reports a combined diffractometric (Synchrotron Radiation XRD with Rietveld and PDF analyses) and spectroscopic (Mössbauer) approach able to give a thorough characterization of the material defectivity. Such analytical procedure has been applied to a sample prepared following an innovative microwave-assisted hydrothermal synthesis route that, in a few minutes, allowed us to obtain a well crystallized material. PDF analysis, which is applied for the first time to this type of battery material, reveals the presence of disorder possibly due to Li/Fe exchange or to a local symmetry lowering. A 5% amount of iron on the lithium site has been detected both by PDF as well as by Mössbauer spectroscopy, which revealed a small percentage of Fe 3+ on the regular sites. © 2012 The Royal Society of Chemistry

    Evaluation of the Classification Accuracy of the Kidney Biopsy Direct Immunofluorescence through Convolutional Neural Networks

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    Background and objectives: Immunohistopathology is an essential technique in the diagnostic workflow of a kidney biopsy. Deep learning is an effective tool in the elaboration of medical imaging. We wanted to evaluate the role of a convolutional neural network as a support tool for kidney immunofluorescence reporting. Design, setting, participants, & measurements: High-magnification ( 7400) immunofluorescence images of kidney biopsies performed from the year 2001 to 2018 were collected. The report, adopted at the Division of Nephrology of the AOU Policlinico di Modena, describes the specimen in terms of \u201cappearance,\u201d \u201cdistribution,\u201d \u201clocation,\u201d and \u201cintensity\u201d of the glomerular deposits identified with fluorescent antibodies against IgG, IgA, IgM, C1q and C3 complement fractions, fibrinogen, and \u3ba- and \u3bb-light chains. The report was used as ground truth for the training of the convolutional neural networks. Results: In total, 12,259 immunofluorescence images of 2542 subjects undergoing kidney biopsy were collected. The test set analysis showed accuracy values between 0.79 (\u201cirregular capillary wall\u201d feature) and 0.94 (\u201cfine granular\u201d feature). The agreement test of the results obtained by the convolutional neural networks with respect to the ground truth showed similar values to three pathologists of our center. Convolutional neural networks were 117 times faster than human evaluators in analyzing 180 test images. A web platform, where it is possible to upload digitized images of immunofluorescence specimens, is available to evaluate the potential of our approach. Conclusions: The data showed that the accuracy of convolutional neural networks is comparable with that of pathologists experienced in the field

    The prevalence of autosomal dominant polycystic kidney disease (ADPKD): A meta-analysis of European literature and prevalence evaluation in the Italian province of Modena suggest that ADPKD is a rare and underdiagnosed condition

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    ADPKD is erroneously perceived as a not rare condition, which is mainly due to the repeated citation of a mistaken interpretation of old epidemiological data, as reported in the Dalgaard's work (1957). Even if ADPKD is not a common condition, the correct prevalence of ADPKD in the general population is uncertain, with a wide range of estimations reported by different authors. In this work, we have performed a meta-analysis of available epidemiological data in the European literature. Furthermore we collected the diagnosis and clinical data of ADPKD in a province in the north of Italy (Modena). We describe the point and predicted prevalence of ADPKD, as well as the main clinical characteristics of ADPKD in this region

    An X-ray and computational study of liquid pentylammonium nitrate

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    In this article we report the study of liquid pentylammonium nitrate with Wide Angle X-ray scattering and AIMD simulations. Static and dynamical features were characterized by comparing the experimental X-ray pattern with ab initio molecular dynamics simulation trajectories. From the analysis, we were able to focus our attention on the nature and time duration of the hydrogen bond network established between cation and anion. Such H-bond interactions occur around 2.8 Å, last about 1.55 ps and lead to the loss of degeneracy of the asymmetric stretching normal mode of the anion, with a splitting of about 84 cm−

    Indagini chimico-fisiche sui suoli del Bacino del Sarno

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    Per la definizione del Piano Stralcio di Tutela delle Acque l’Autorità di Bacino del Sarno ha dato incarico al Dipartimento di Chimica dell’Università “Federico II” di Napoli di effettuare analisi chimico- fisiche su un lotto di 40 - 50 unità di campioni di suolo relativamente ai parametri: granulometria, pH, capacità di scambio cationici, metalli “pesanti” (antimonio, arsenico, berillio, cadmio, cobalto, cromo totale, cromo (VI), mercurio, nichel, piombo, rame, selenio, stagno, tallio, vanadio, zinco), anioni inorganici (cloruri, fosfati, solfati, fluoruri, cianuri), azoto ammoniacale, nitroso e nitrico, % materiale organico, IPA, PCB e pesticidi organoclorurati, Idrocarburi (C12). Dai risultati ottenuti per i vari campioni di suolo prelevati è emerso che in nessun caso e per nessun parametro chimico vengono superati i limiti della colonna B, il che significa che non ci troviamo mai in condizioni di grave inquinamento. Al contrario invece, in diversi casi, abbiamo suoli con uno o più parametri che superano i limiti di colonna A

    The effects of carboxylic acids on the aqueous dispersion and electrophoretic deposition of ZrO2

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    The agglomeration, electrokinetic properties and electrophoretic deposition behaviour of aqueous suspensions of ZrO2 with carboxylic acid additives were studied in comparison with conventional pH adjustment. It was found that citric acid imparted negative zeta-potential values and electrosteric stabilisation to particles in suspensions at all pH levels. The examination of additions of carboxylic acids to ZrO2 suspensions revealed that these reagents cause a sharp drop in zeta-potential at distinct addition levels, which correspond to surface saturation of the particles with negatively charged carboxylate groups. Adsorption cross sections of citric acid, EDTA and oxalic acid were evaluated from these results, showing that both citric acid and EDTA coordinate to ZrO2 surfaces by two carboxylate groups while oxalic acid is coordinated by one group. The use of carboxylic acids was shown to facilitate superior electrophoretic deposition in comparison with zeta-potential modification by conventional pH adjustment through improved suspension stability. \ua9 2011 Elsevier Ltd
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