26 research outputs found

    A numerical model for NVH analysis of gearboxes employed on agricultural equipment

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    The aim of this paper is to describe a numerical vibro-acoustic methodology, experimentally assessed, for the estimation of the overall vibratory and acoustic level of a gearbox employed on agricultural equipment. The process is carried out in order to create the NVH digital twin of the real gearbox. The vibro-acoustic model is the combination of three sub-models: a lumped-parameter (LP) model, a structural finite-element (SFE) model and an acoustical finite-element (AFE) model. The LP model is used to obtain the reaction forces on the bearings during working conditions. Reaction forces are employed as an input for the further SFE dynamic model to evaluate the dynamic response of the gearbox’s case, which is the only meshed part. The dynamic response is exploited to set-up an AFE model which allows to estimate the noise generation in terms of overall acoustic pressure. The numerical simulation results are validated using experimental data acquired on a real gearbox. Testing activities have been carried out at Comer Industries facility in Reggiolo, where specimens and test benches have been set. Advantages and limitations of the model are reported

    Differential activation of Fyn kinase distinguishes saturated and unsaturated fats in mouse macrophages.

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    Diet-induced obesity is associated with increased adipose tissue activated macrophages. Yet, how macrophages integrate fatty acid (FA) signals remains unclear. We previously demonstrated that Fyn deficiency (fynKO) protects against high fat diet-induced adipose tissue macrophage accumulation. Herein, we show that inflammatory markers and reactive oxygen species are not induced in fynKO bone marrow-derived macrophages exposed to the saturated FA palmitate, suggesting that Fyn regulates macrophage function in response to FA signals. Palmitate activates Fyn and re-localizes Fyn into the nucleus of RAW264.7, J774 and wild-type bone marrow-derived macrophages. Similarly, Fyn activity is increased in cells of adipose tissue stromal vascular fraction of high fat-fed control mice, with Fyn protein being located in the nucleus of these cells. We demonstrate that Fyn modulates palmitate-dependent oxidative stress in macrophages. Moreover, Fyn catalytic activity is necessary for its nuclear re-localization and downstream effects, as Fyn pharmacological inhibition abolishes palmitate-induced Fyn nuclear redistribution and palmitate-dependent increase of oxidative stress markers. Importantly, mono-or polyunsaturated FAs do not activate Fyn, and fail to re-localize Fyn to the nucleus. Together these data demonstrate that macrophages integrate nutritional FA signals via a differential activation of Fyn that distinguishes, at least partly, the effects of saturated versus unsaturated fats

    Alteration of de novo glucose production contributes to fasting hypoglycaemia in fyn deficient mice

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    Previous studies have demonstrated that glucose disposal is increased in the Fyn knockout (FynKO) mice due to increased insulin sensitivity. FynKO mice also display fasting hypoglycaemia despite decreased insulin levels, which suggested that hepatic glucose production was unable to compensate for the increased basal glucose utilization. The present study investigates the basis for the reduction in plasma glucose levels and the reduced ability for the liver to produce glucose in response to gluconeogenic substrates. FynKO mice had a 5-fold reduction in phosphoenolpyruvate carboxykinase (PEPCK) gene and protein expression and a marked reduction in pyruvate, pyruvate/lactate-stimulated glucose output. Remarkably, de novo glucose production was also blunted using gluconeogenic substrates that bypass the PEPCK step. Impaired conversion of glycerol to glucose was observed in both glycerol tolerance test and determination of the conversion of 13C-glycerol to glucose in the fasted state. α-glycerol phosphate levels were reduced but glycerol kinase protein expression levels were not changed. Fructose-driven glucose production was also diminished without alteration of fructokinase expression levels. The normal levels of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate observed in the FynKO liver extracts suggested normal triose kinase function. Fructose-bisphosphate aldolase (aldolase) mRNA or protein levels were normal in the Fyn-deficient livers, however, there was a large reduction in liver fructose-6-phosphate (30-fold) and fructose-1,6-bisphosphate (7-fold) levels as well as a reduction in glucose-6-phosphate (2-fold) levels. These data suggest a mechanistic defect in the allosteric regulation of aldolase activity

    Chemical characterization of cherry (Prunus avium) extract in comparison with commercial mimosa and chestnut tannins

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    In a growing context of green and circular economy, gaining knowledge of the composition of every crop is crucial, as this will allow for their full exploitation. Cherry (Prunus avium L.) is a widespread tree of particular interest for its fruits and its valuable timber. Its wood is rich in extractives and its characterization will allow to consider other applications for this feedstock. In this study, chipped cherry wood was extracted and chemically analysed to determine its total phenolic content, total condensed tannin, antioxidant capacity, and polysaccharide content through wet chemistry analysis. These investigations were coupled with C-13-NMR and FTIR spectrometry, with HPLC as well as elemental analysis to conduct a comprehensive chemical characterization. Thermogravimetric measurements were also taken to understand the behaviour of the extract when exposed to high temperature. The registered findings were benchmarked against commercial mimosa (Acacia mearnsii De Wild.) and chestnut (Castanea sativa Mill.) tannins which were selected as template for condensed and hydrolysable tannins, respectively. Cherry extract was found to be the poorest in phenolics which are mainly constituted of pyrogallic flavonoids strongly interconnected with significant amounts of polysaccharides

    The obesity gene and colorectal cancer risk: a population study in northern Italy

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    Background: Representing the second cause of cancer-related death after lung cancer in men and breast cancer in women, colorectal cancer (CRC) is a major health problemin Italy. Obesity is reckoned to favor CRC; however, the underlying mechanisms are unclear. Recently, a single nucleotide polymorphism (SNP) in the fat mass and obesity associated (FTO) gene was found to be significantly associated with obesity. Aims: To establish whether the FTO SNP rs9939609 may represent a risk factor for CRC and adenoma in the Italian population. Patients and methods: 1,037 subjects were enrolled in the study and divided in 3 groups: CRC (341 pts., M/ F=197/144, mean age=65.17±11.16 years), colorectal adenoma (385 pts., M/F=247/138, mean age=62.49±13.01 years), healthy controls (311 pts., M/F=150/161, mean age=57.31±13.84 years). DNA was extracted from whole blood, and stored frozen for rs9939609 genotyping by real-time PCR. Results: The frequency of the obesity-associatedmutated A allele (AA+AT) on the FTO gene was 69.77% among controls, and 71.85% and 65.71% respectively among CRC and polyp patients. Compared to control subjects the AA+AT genotype had no significant effect on the risk for either CRC (OR=1.106; CI 95%=0.788–1.550; p=0.561) or colorectal adenomas (OR=0.830; CI 95%=0.602–1.144; p=0.255). We did not observe any association between the AA genotype and CRC/polyp localization and age at diagnosis. As measured in a patient subset, carriership of the risk alleles did not reflect in a significantly altered BMI. Conclusion: The obesity-linked FTO variants do not play a significant role in modulating the colorectal cancer risk in the Italian population
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