67 research outputs found

    Corrosion Behaviour of Room Temperature Cured Polysilazane-Derived Silica Coatings on Al 5086

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    Silica coatings from polysilazane precursors were prepared to protect aluminium substrates from corrosion. Polysilazane can be converted to silica by simple exposition to air or basic vapours and the properties of the synthesized film make this precursor a valuable choice to obtain solid, crack-free, highly adhesive and protective coatings. The optimal deposition, obtained at 15 cm min-1 of dip-coating withdrawal speed, 20% PHPS precursor in n-butyl ether, 24 hours of exposition to 10% ammonia vapours and 6 days of ageing in air, manages to slow down the corrosion process by three orders of magnitude, therefore providing a longer lasting commodity. Specimens have been characterized by IR and XPS spectroscopy, AFM imaging and electrochemical studies

    Acoustic quality of auditoria: Relationship between acoustical energy parameters and subjective perception

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    The acoustic design auditoria is founded on objective acoustic parameters determined on the basis of the computed or measured impulse response. Such objective parameters are related on the average response of the human ear to transient sounds, without considering the subjective perception of the individual, which, in turn, is related also to social and education aspects. The aim of this study is to investigate the relationship between individual sound perceptions and energy parameters. In detail, a questionnaire has been submitted to a sample of people listening to tracks of different musical genres. The questionnaire has been conceived to come up with a classification model for the audience allowing to express the listener's experience according to different indicators, such as overall acoustic quality and overall acoustic experience. Results of this experiment are analyzed by means of Random Forest non-parametric model belonging to the data mining algorithms. The final purpose of the study is to define which physical and acoustical characteristics are the most suitable to represent the subjective perceptions of the listeners

    Calcium-sensing receptor and calcium kidney stones

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    Calcium nephrolithiasis may be considered as a complex disease having multiple pathogenetic mechanisms and characterized by various clinical manifestations. Both genetic and environmental factors may increase susceptibility to calcium stones; therefore, it is crucial to characterize the patient phenotype to distinguish homogeneous groups of stone formers. Family and twin studies have shown that the stone transmission pattern is not mendelian, but complex and polygenic. In these studies, heritability of calcium stones was calculated around 50

    Trehalose induces autophagy via lysosomal-mediated TFEB activation in models of motoneuron degeneration

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    Macroautophagy/autophagy, a defense mechanism against aberrant stresses, in neurons counteracts aggregate-prone misfolded protein toxicity. Autophagy induction might be beneficial in neurodegenerative diseases (NDs). The natural compound trehalose promotes autophagy via TFEB (transcription factor EB), ameliorating disease phenotype in multiple ND models, but its mechanism is still obscure. We demonstrated that trehalose regulates autophagy by inducing rapid and transient lysosomal enlargement and membrane permeabilization (LMP). This effect correlated with the calcium-dependent phosphatase PPP3/calcineurin activation, TFEB dephosphorylation and nuclear translocation. Trehalose upregulated genes for the TFEB target and regulator Ppargc1a, lysosomal hydrolases and membrane proteins (Ctsb, Gla, Lamp2a, Mcoln1, Tpp1) and several autophagy-related components (Becn1, Atg10, Atg12, Sqstm1/p62, Map1lc3b, Hspb8 and Bag3) mostly in a PPP3- and TFEB-dependent manner. TFEB silencing counteracted the trehalose pro-degradative activity on misfolded protein causative of motoneuron diseases. Similar effects were exerted by trehalase-resistant trehalose analogs, melibiose and lactulose. Thus, limited lysosomal damage might induce autophagy, perhaps as a compensatory mechanism, a process that is beneficial to counteract neurodegeneration

    Coronavirus e ambiente: una sfida per il pianeta e per la salute

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    In late December 2019, some patients were hospitalized with an initial diagnosis of pneumonia of unknown etiology. These patients were epidemiologically linked to a wholesale market of seafood, wild animals and meat located in Wuhan, Hubei province, China. Acute respiratory disease caused by a new Coronavirus SARS-CoV-2, formerly known as 2019-nCoV, afterwards as Coronavirus disease 2019 (COVID-19), spread throughout China and received the attention of the entire world. Analysis of the genomic sequence of COVID-19 showed 88% of identity with two bat-derived severe acute respiratory syndrome-like Coronaviruses. Illegal and sustainable wildlife trade is the second largest direct threat to species after habitat destruction. Each year, hundreds of millions of plants and animals are captured or collected in the wild to be sold as food, pets, medicines, ornaments and for a variety of other reasons. Even the climate crisis could offer dangerous scenarios in addition to another fundamental chapter of the environmental pillar which is the one concerning air quality. There is a solid scientific literature which correlates the incidence of viral infection cases with concentrations of atmospheric particulate matter (e.g. PM10 and PM2.5). Despite the current regulations, which limit the levels of certain atmospheric pollutants, there are still numerous negative health effects deriving from exposure to these agents. However, it can be said that chronic air pollution, such as peaks of concentration of fine dust and other pollutants, acts as a pejorative factor in cases of epidemics. (GCND_planet

    L'infermiere e la percezione del Moral Distress nella cura del fine vita nel paziente dializzato

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    The phenomenon of Moral Distress in nursing practice is described as a situation of suffering that arises when the nurse recognizes the ethically appropriate action to be taken and yet institutional impediments make it impossible for him to follow the right course of action. Dialysis patients often have a complex disease trajectory that sometimes involves professional and emotional challenges for staff, especially at the end of life. The objective of this review is to identify which strategies are useful for preserving emotional integrity and awareness in operational settings, for the benefit of both operators and patients

    The small heat shock protein B8 (HSPB8) efficiently removes aggregating species of dipeptides produced in C9ORF72-related neurodegenerative diseases

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    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two neurodegenerative diseases in which similar pathogenic mechanisms are involved. Both diseases associate to the high propensity of specific misfolded proteins, like TDP-43 or FUS, to mislocalize and aggregate. This is partly due to their intrinsic biophysical properties and partly as a consequence of failure of the neuronal protein quality control (PQC) system. Several familial ALS/FTD cases are linked to an expansion of a repeated G4C2 hexanucleotide sequence present in the C9ORF72 gene. The G4C2, which localizes in an untranslated region of the C9ORF72 transcript, drives an unconventional repeat-associated ATG-independent translation. This leads to the synthesis of five different dipeptide repeat proteins (DPRs), which are not âclassicalâ misfolded proteins, but generate aberrant aggregation-prone unfolded conformations poorly removed by the PQC system. The DPRs accumulate into p62/SQSTM1 and ubiquitin positive inclusions. Here, we analyzed the biochemical behavior of the five DPRs in immortalized motoneurons. Our data suggest that while the DPRs are mainly processed via autophagy, this system is unable to fully clear their aggregated forms, and thus they tend to accumulate in basal conditions. Overexpression of the small heat shock protein B8 (HSPB8), which facilitates the autophagy-mediated disposal of a large variety of classical misfolded aggregation-prone proteins, significantly decreased the accumulation of most DPR insoluble species. Thus, the induction of HSPB8 might represent a valid approach to decrease DPR-mediated toxicity and maintain motoneuron viability

    Tdp-25 Routing to Autophagy and Proteasome Ameliorates its Aggregation in Amyotrophic Lateral Sclerosis Target Cells

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that primarily affects motoneurons, while non-neuronal cells may contribute to disease onset and progression. Most ALS cases are characterized by the mislocalization and aggregation of the TAR DNA binding protein 43 (TDP-43) in affected cells. TDP-43 aggregates contain C-terminal TDP-43 fragments of 35 kDa (TDP-35) and 25 kDa (TDP-25) and have been mainly studied in motoneurons, while little is currently known about their rate of accumulation and clearance in myoblasts. Here, we performed a comparative study in immortalized motoneuronal like (NSC34; i-motoneurons) cells and stabilized myoblasts (C2C12; s-myoblasts) to evaluate if these two cell types differentially accumulate and clear TDP forms. The most aggregating specie in i-motoneurons is the TDP-25 fragment, mainly constituted by the \u201cprion-like\u201d domain of TDP-43. To a lower extent, TDP-25 also aggregates in s-myoblasts. In both cell types, all TDP species are cleared by proteasome, but TDP-25 impairs autophagy. Interestingly, the routing of TDP-25 fragment to proteasome, by overexpressing BAG1, or to autophagy, by overexpressing HSPB8 or BAG3 decreased its accumulation in both cell types. These results demonstrate that promoting the chaperone-assisted clearance of ALS-linked proteins is beneficial not only in motoneurons but also in myoblasts
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