1,097 research outputs found

    Pigments in extra virgin olive oils produced in different mediterranean countries in 2014: Near UV-vis spectroscopy versus HPLC-DAD

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    Carotenoids and chlorophyll derivatives play a key role in Extra Virgin Olive Oils (EVOOs). Many factors, such as cultivar, geographic origin, maturity of olives, climate and storage conditions, influence the pigments’ content. The quantification of pigments is usually done by chromatographic techniques. However, recent works evidenced the potentialities of UV-visible-related methodologies. In this research, a selection of EVOO samples produced from olives harvested at the beginning of November 2014 in Greece, Tunisia, Italy and Spain, was investigated in terms of pigments by means of two methods. The first one is a recent approach based on the mathematical treatment of near UV-vis absorption spectra of olive oils to quantify in a fast, cheap and non-destructive way four main pigments, namely b-carotene, lutein, pheophytin A and pheophytin B. The second one is a more standard HPLC-DAD method. From the comparison between the two methods, we can conclude that the new near UV-vis approach gives reliable results, with good precision and high reproducibility. Pigments quantified by these two methods in EVOOs produced in four countries from different cultivars are analyzed by principal component analysis (PCA). Results indicate that pigments can be correlated to several factors such as ripeness stage, geographic origin and cultivars

    Block-Based Models and Theorem Proving in Model-Based Development

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    This paper presents a methodology to integrate computer-assisted theorem proving into a standard workflow for model-based development that uses a block-based language as a modeling and simulation tool. The theorem prover provides confidence in the results of the analysis as it guides the developers towards a correct formalization of the system under development

    Design and Validation of Cyber-Physical Systems Through Co-Simulation: The Voronoi Tessellation Use Case

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    This paper reports on the use of co-simulation techniques to build prototypes of co-operative autonomous robotic cyber-physical systems. Designing such systems involves a mission-specific planner algorithm, a control algorithm to drive an agent performing its task; and the plant model to simulate the agent dynamics. An application aimed at positioning a swarm of unmanned aerial vehicles (drones) in a bounded area, exploiting a Voronoi tessellation algorithm developed in this work, is taken as a case study. The paper shows how co-simulation allows testing the complex system at the design phase using models created with different languages and tools. The paper then reports on how the adopted co-simulation platform enables control parameters calibration, by exploiting design space exploration technology. The INTO-CPS co-simulation platform, compliant with the Functional Mock-up Interface standard to exchange dynamic simulation models using various languages, was used in this work. The different software modules were written in Modelica, C, and Python. In particular, the latter was used to implement an original variant of the Voronoi algorithm to tesselate a convex polygonal region, by means of dummy points added at appropriate positions outside the bounding polygon. A key contribution of this case study is that it demonstrates how an accurate simulation of a cooperative drone swarm requires modeling the physical plant together with the high-level coordination algorithm. The coupling of co-simulation and design space exploration has been demonstrated to support control parameter calibration to optimize energy consumption and convergence time to the target positions of the drone swarm. From a practical point of view, this makes it possible to test the ability of the swarm to self-deploy in space in order to achieve optimal detection coverage and allow unmanned aerial vehicles in a swarm to coordinate with each other

    Formal verification and co-simulation in the design of a synchronous motor control algorithm

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    Mechatronic systems are a class of cyber-physical systems, whose increasing complexity makes their validation and verification more and more difficult, while their requirements become more challenging. This paper introduces a development method based on model-based design, co-simulation and formal verification. The objective of this paper is to show the applicability of the method in an industrial setting. An application case study comes from the field of precision servo-motors, where formal verification has been used to find acceptable intervals of values for design parameters of the motor controller, which have been further explored using co-simulation to find optimal values. The reported results show that the method has been applied successfully to the case study, augmenting the current model-driven development processes by formal verification of stability, formal identification of acceptable parameter ranges, and automatic design-space exploration

    Ultrasound delivery of Surface Enhanced InfraRed Absorption active gold-nanoprobes into fibroblast cells: a biological study via Synchrotron-based InfraRed microanalysis at single cell level

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    Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation fourier transform infrared micro-spectroscopy (SR-microftiR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR- microftiR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies

    Polyamine oxidase is involved in spermidine reduction of transglutaminase type 2-catalyzed βh-crystallins polymerization in calcium-induced experimental cataract

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    In an in vitro Ca2+-induced cataract model, the progression of opacification is paralleled by a rapid decrease of the endogenous levels of spermidine (SPD) and an increase of transglutaminase type 2 (TG2, EC 2.3.2.13)-catalyzed lens crystallins cross-linking by protein-boundN(1)-N-8-bis(gamma-glutamyl) SPD. This pattern was reversed adding exogenous SPD to the incubation resulting in a delayed loss of transparency of the rabbit lens. The present report shows evidence on the main incorporation of SPD by the catalytic activity of TG2, toward beta H-crystallins and in particular to the beta B2- and mostly in beta B3-crystallins. The increase of endogenous SPD in the cultured rabbit lens showed the activation of a flavin adenine dinucleotide (FAD)-dependent polyamine oxidases (PAO EC 1.5.3.11). As it is known that FAD-PAO degrades theN(8)-terminal reactive portion ofN(1)-mono(gamma-glutamyl) SPD, the protein-boundN(8)-mono(gamma-glutamyl) SPD was found the mainly available derivative for the potential formation of beta B3-crystallins cross-links by protein-boundN(1)-N-8-bis(gamma-glutamyl)SPD. In conclusion, FAD-PAO degradation of theN(8)-terminal reactive residue of the crystallins boundN(1)-mono(gamma-glutamyl)SPD together with the increased concentration of exogenous SPD, leading to saturation of glutamine residues on the substrate proteins, drastically reducesN(1)-N-8-bis(gamma-glutamyl)SPD crosslinks formation, preventing crystallins polymerization and avoiding rabbit lens opacification. The ability of SPD and MDL 72527 to modulate the activities of TG2 and FAD-PAO involved in the mechanism of lens opacification suggests a potential strategy for the prevention of senile cataract

    Plasma protein biomarkers for depression and schizophrenia by multi analyte profiling of case-control collections.

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    Despite significant research efforts aimed at understanding the neurobiological underpinnings of psychiatric disorders, the diagnosis and the evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms. Therefore, biological markers which could improve the current classification of psychiatry disorders, and in perspective stratify patients on a biological basis into more homogeneous clinically distinct subgroups, are highly needed. In order to identify novel candidate biological markers for major depression and schizophrenia, we have applied a focused proteomic approach using plasma samples from a large case-control collection. Patients were diagnosed according to DSM criteria using structured interviews and a number of additional clinical variables and demographic information were assessed. Plasma samples from 245 depressed patients, 229 schizophrenic patients and 254 controls were submitted to multi analyte profiling allowing the evaluation of up to 79 proteins, including a series of cytokines, chemokines and neurotrophins previously suggested to be involved in the pathophysiology of depression and schizophrenia. Univariate data analysis showed more significant p-values than would be expected by chance and highlighted several proteins belonging to pathways or mechanisms previously suspected to be involved in the pathophysiology of major depression or schizophrenia, such as insulin and MMP-9 for depression, and BDNF, EGF and a number of chemokines for schizophrenia. Multivariate analysis was carried out to improve the differentiation of cases from controls and identify the most informative panel of markers. The results illustrate the potential of plasma biomarker profiling for psychiatric disorders, when conducted in large collections. The study highlighted a set of analytes as candidate biomarker signatures for depression and schizophrenia, warranting further investigation in independent collections

    Different gene expression modulation is the major effect fue to shear stress and stent application in huvecs model: preliminary results

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    Although it is known that disturbed shear stress may cause endothelial damage, the mechanism by which a stent procedure may affect the endothelium is not yet fully clarify. We present the preliminary data on gene expression analysis of human endothelial cells in a laminar flow bioreactor (LFB) system submitted to different physical (flow changes) and/or mechanical (stent application) stimuli. Our preliminary results show that low shear stress together with stent procedure are the experimental conditions that mainly modulate the highest number of genes in human endothelial model. Those genes belong to pathways specifically involved in the endothelial dysfunctio

    High-resolution tracking in a GEM-Emulsion detector

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    SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the CERN SPS aiming at the observation of long lived particles very weakly coupled with ordinary matter mostly produced in the decay of charmed hadrons. The beam dump facility of SHiP is also a copious factory of neutrinos of all three kinds and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus. The neutrino detector exploits the Emulsion Cloud Chamber technique with a modular structure, alternating walls of target units and planes of electronic detectors providing the time stamp to the event. GEM detectors are one of the possible choices for this task. This paper reports the results of the first exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the emulsion detector, the position resolution of the GEM chamber as a function of the particle inclination was evaluated in two configurations, with and without the magnetic fiel
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