17 research outputs found

    Developing models for future real-time platforms: Virtual simulation and design of new components and systems for aircraft and remotely piloted aircraft systems

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    In the development of electrified and other vehicle systems, the modelling and simulation of the vehicle is very important. With these tools the preliminary design, as well as later detailed studies of the systems developed, allow engineers to spend less time on each phase of their projects or address them with an integrated approach. In addition, this integrated approach provides the possibility of building hardware-in-the loop models with all the components required. This vehicle modelling and simulation has gained more interest with the increasing use of a wide variety of RPAS, ranging from light weight micro aircraft to large vehicles of various tons. For this reason, the previously-described building tools are the final objective of the developing models to be used in real-time platform projects. The first step presented in this paper is to build a simulator that reproduces the behaviour of a selected aircraft and validate it. This paper presents the study of the performances and behaviour of an OPV used to validate the simulator developed later. At the end, some preliminary tests and estimations of the performances for the selected OPV with an electric motor are presented

    Electrochemical Capacitance DNA Sensing at Hairpin-Modified Au Electrodes

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    An interfacial capacitance measurement electrochemical technique has been used for the sensing of self-assembled DNA hairpin probes (M. tuberculosis and B. anthracis) attached to Au electrodes. The double-layer capacitance (Cdl) was determined with electrochemical perturbations from 0.2 V to 0.5 V versus Ag/AgCl at a Au/M. tuberculosis DNA hairpin probe at surface coverage Au electrodes. The capacitance study was done at pH 7, which was necessary to maintain the M. tuberculosis and B. anthracis DNA probes closed during the electrochemical perturbation. Detailed experimental analysis carried out by repetitively switching the electrochemical potential between 0.2 and 0.5 V (versus Ag/AgCl) strongly supports the use of capacitance measurements as a tool to detect the hybridization of DNA targets. A large change in the capacitance deference between 0.2 and 0.5 V was observed in the DNA hybridization process. Therefore, no fluorophores or secondary transducers were necessary to sense a DNA target for both DNA hairpins

    Biosensing for the Environment and Defence: Aqueous Uranyl Detection Using Bacterial Surface Layer Proteins

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    The fabrication of novel uranyl (UO22+) binding protein based sensors is reported. The new biosensor responds to picomolar levels of aqueous uranyl ions within minutes using Lysinibacillus sphaericus JG-A12 S-layer protein tethered to gold electrodes. In comparison to traditional self assembled monolayer based biosensors the porous bioconjugated layer gave greater stability, longer electrode life span and a denser protein layer. Biosensors responded specifically to UO22+ ions and showed minor interference from Ni2+, Cs+, Cd2+ and Co2+. Chemical modification of JG-A12 protein phosphate and carboxyl groups prevented UO22+ binding, showing that both moieties are involved in the recognition to UO22+

    Direct association between pharyngeal viral secretion and host cytokine response in severe pandemic influenza

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    <p>Abstract</p> <p>Background</p> <p>Severe disease caused by 2009 pandemic influenza A/H1N1virus is characterized by the presence of hypercytokinemia. The origin of the exacerbated cytokine response is unclear. As observed previously, uncontrolled influenza virus replication could strongly influence cytokine production. The objective of the present study was to evaluate the relationship between host cytokine responses and viral levels in pandemic influenza critically ill patients.</p> <p>Methods</p> <p>Twenty three patients admitted to the ICU with primary viral pneumonia were included in this study. A quantitative PCR based method targeting the M1 influenza gene was developed to quantify pharyngeal viral load. In addition, by using a multiplex based assay, we systematically evaluated host cytokine responses to the viral infection at admission to the ICU. Correlation studies between cytokine levels and viral load were done by calculating the Spearman correlation coefficient.</p> <p>Results</p> <p>Fifteen patients needed of intubation and ventilation, while eight did not need of mechanical ventilation during ICU hospitalization. Viral load in pharyngeal swabs was 300 fold higher in the group of patients with the worst respiratory condition at admission to the ICU. Pharyngeal viral load directly correlated with plasma levels of the pro-inflammatory cytokines IL-6, IL-12p70, IFN-γ, the chemotactic factors MIP-1β, GM-CSF, the angiogenic mediator VEGF and also of the immuno-modulatory cytokine IL-1ra (p < 0.05). Correlation studies demonstrated also the existence of a significant positive association between the levels of these mediators, evidencing that they are simultaneously regulated in response to the virus.</p> <p>Conclusions</p> <p>Severe respiratory disease caused by the 2009 pandemic influenza virus is characterized by the existence of a direct association between viral replication and host cytokine response, revealing a potential pathogenic link with the severe disease caused by other influenza subtypes such as H5N1.</p

    In Situ Fluorescence Microscopy Study of the Interfacial Inhomogeneity of DNA Mixed Self-Assembled Monolayers at Gold Electrodes

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    Mixed self-assembled monolayers (SAMs) composed of a fluorescently labeled DNA and a mercaptobutanol diluent immobilized on gold electrodes were characterized by electrochemical measurements coupled with in situ fluorescence microscopy. The reductive desorption of the SAMs was monitored in real time through the variations of capacitance and fluorescence intensity. Desorption occurs in several steps, related to the substrate crystallinity. Fluorescence microscopy revealed the presence of spatial heterogeneities in the form of highly fluorescent aggregates that remain at the electrode surface even after a reductive desorption step.This in situ electrofluorescence microscopy technique is useful to optimize the formation of the mixed layer to obtain a homogeneous distribution of the probes and thus to improve the efficiency of the recognition process in the development of biosensors.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe
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