514 research outputs found

    Improved Zn-based coatings for ipersandelin steel products

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    The protection of iron-based alloy products against corrosion is fundamental to preserve their mechanical properties in aggressive environments. Hot-dip galvanizing process represents one of the most used techniques to make protective coatings for such products. In order to improve both mechanical and chemical properties of coating, metallic elements may be added to the traditional zinc bath. In the present paper, two types of improved zinc-based coating are proposed: (i) A coating obtained employing a tin addition (3% in weight); (ii) A coating obtained employing aluminium (5% in weight), tin (1% in weight) and copper (0.5% in weight) additions. Firstly, the performance of such two types of coatings is experimentally investigated through bending tests on ipersandelin steel plate specimens, treated through different bath dipping times. The intermetallic phase thicknesses of coatings are measured for each dipping time, in order to evaluate the kinetic formation. Then, a Finite Element (FE) model is proposed in order to simulate the bending behaviour of the above specimens, both employing the measured phase thickness and implementing the loading and boundary conditions of the experimental tests. A numerical non-linear static analysis is performed. A quite satisfactory agreement between experimental and numerical results is observed, especially under plastic behaviour regime

    Mechanical behaviour and phase transition mechanisms of a shape memory alloy by means of a novel analytical model

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    The aim of the present paper is to examine both the fatigue behaviour and the phase transition mechanisms of an equiatomic pseudo-elastic NiTi Shape Memory Alloy through cyclic tests (up to 100 loading cycles). More precisely, miniaturised dog-bone specimens are tested by using a customised testing machine and the contents of both austenite and martensite phase are experimentally measured by means of X-Ray diffraction (XRD) analyses. On the basis of such experimental results in terms of martensite content, an analytical model is here formulated to correlate the stress-strain relationship to the phase transition mechanisms. Finally, a validation of the present model by means of experimental data pertaining the stress-strain relationship is performed

    Dysregulated homeostasis of acetylcholine levels in immune cells of RR-multiple sclerosis patients

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    Multiple sclerosis (MS) is characterized by pro-inflammatory cytokine production. Acetylcholine (ACh) contributes to the modulation of central and peripheral inflammation. We studied the homeostasis of the cholinergic system in relation to cytokine levels in immune cells and sera of relapsing remitting-MS (RR-MS) patients. We demonstrated that lower ACh levels in serum of RR-MS patients were inversely correlated with the increased activity of the hydrolyzing enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Interestingly, the expression of the ACh biosynthetic enzyme and the protein carriers involved in non-vesicular ACh release were found overexpressed in peripheral blood mononuclear cells of MS patients. The inflammatory state of the MS patients was confirmed by increased levels of TNF alpha, IL-12/IL-23p40, IL-18. The lower circulating ACh levels in sera of MS patients are dependent on the higher activity of cholinergic hydrolyzing enzymes. The smaller ratio of ACh to TNF alpha, IL-12/IL-23p40 and IL-18 in MS patients, with respect to healthy donors (HD), is indicative of an inflammatory environment probably related to the alteration of cholinergic system homeostasis

    Real-life Evidence of Lower Lung Virulence in COVID-19 Inpatients Infected with SARS-CoV-2 Omicron Variant Compared to Wild-Type and Delta SARS-CoV-2 Pneumonia

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    In vitro and animal models described lower replication capacity and virulence of SARS-CoV-2 Omicron lineage in lower respiratory airways compared to wild type and other variants of concern (oVOCs). Among adult subjects admitted to our hospital (Turin, Italy) due to wild type, oVOCs, and Omicron SARS-CoV-2-related pneumonia (n = 100 for each lineage), the cases of Omicron pneumonia showed lower degree of lung parenchyma involvement (aβ -1.471, p = 0.037), less tendency to parenchyma consolidation (aOR 0.500, p = 0.011), and better respiratory functions (assessed by ambient air arterial blood gas analysis). After adjusting for demographic, previous immunity, and comorbidities, Omicron pneumonia still associated with lower risk of respiratory failure (for severe respiratory failure, Wild-type versus Omicron aOR 15.6, p = 0.005 and oVOCs versus Omicron aOR 31.7, p < 0.001). These observations are in line with preliminary findings from in vitro and animal models and could explain why Omicron infection has been associated with lower mortality and hospitalization in human

    Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome

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    Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7±3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p<0.005) and BTT (p<0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p<0.0001) and significantly lower 25(OH)D (p<0.0001), osteocalcin (p<0.05), and bone alkaline phosphatase levels (p<0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages

    Precursor and mature NGF live tracking: one versus many at a time in the axons

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    The classical view of nerve growth factor (NGF) action in the nervous system is linked to its retrograde axonal transport. However, almost nothing is known on the trafficking properties of its unprocessed precursor proNGF, characterized by different and generally opposite biological functions with respect to its mature counterpart. Here we developed a strategy to fluorolabel both purified precursor and mature neurotrophins (NTs) with a controlled stoichiometry and insertion site. Using a single particle tracking approach, we characterized the axonal transport of proNGF versus mature NGF in living dorsal root ganglion neurons grown in compartmentalized microfluidic devices. We demonstrate that proNGF is retrogradely transported as NGF, but with a lower flux and a different distribution of numbers of neurotrophins per vesicle. Moreover, exploiting a dual-color labelling technique, we analysed the transport of both NT forms when simultaneously administered to the axon tips

    Precursor and mature NGF live tracking: one versus many at a time in the axons

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    The classical view of nerve growth factor (NGF) action in the nervous system is linked to its retrograde axonal transport. However, almost nothing is known on the trafficking properties of its unprocessed precursor proNGF, characterized by different and generally opposite biological functions with respect to its mature counterpart. Here we developed a strategy to fluorolabel both purified precursor and mature neurotrophins (NTs) with a controlled stoichiometry and insertion site. Using a single particle tracking approach, we characterized the axonal transport of proNGF versus mature NGF in living dorsal root ganglion neurons grown in compartmentalized microfluidic devices. We demonstrate that proNGF is retrogradely transported as NGF, but with a lower flux and a different distribution of numbers of neurotrophins per vesicle. Moreover, exploiting a dual-color labelling technique, we analysed the transport of both NT forms when simultaneously administered to the axon tips

    Machine-Learning-Based Tool to Predict Target Prostate Biopsy Outcomes: An Internal Validation Study

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    Abstract: The aim of this study is to present a personalized predictive model (PPM) with a machine learning (ML) system that is able to identify and classify patients with suspected prostate cancer (PCa) following mpMRI. We extracted all the patients who underwent fusion biopsy (FB) from March 2014 to December 2019, while patients from August 2020 to April 2021 were included as a validation set. The proposed system was based on the following four ML methods: a fuzzy inference system (FIS), the support vector machine (SVM), k-nearest neighbors (KNN), and self-organizing maps (SOMs). Then, a system based on fuzzy logic (FL) + SVM was compared with logistic regression (LR) and standard diagnostic tools. A total of 1448 patients were included in the training set, while 181 patients were included in the validation set. The area under the curve (AUC) of the proposed FIS + SVM model was comparable with the LR model but outperformed the other diagnostic tools. The FIS + SVM model demonstrated the best performance, in terms of negative predictive value (NPV), on the training set (78.5%); moreover, it outperformed the LR in terms of specificity (92.1% vs. 83%). Considering the validation set, our model outperformed the other methods in terms of NPV (60.7%), sensitivity (90.8%), and accuracy (69.1%). In conclusion, we successfully developed and validated a PPM tool using the FIS + SVM model to calculate the probability of PCa prior to a prostate FB, avoiding useless ones in 15% of the cases
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