Modélisation et commande d'un robot parallèle à câbles pour la rééducation des membres inférieurs

L'utilisation de systèmes robotiques en réadaptation médicale présente un certain nombre d'avantages par rapport à la thérapie traditionnelle, tels qu'une bonne répétabilité de mouvement, une assistance contrôlable avec précision et des mesures de performance quantifiables. Récemment, une nouvelle classe de systèmes robotiques, appelés robots parallèles à câbles, a été introduite dans le domaine de la réadaptation médicale. Dans de tels mécanismes, l'effecteur est entraîné directement par des câbles au lieu de liaisons rigides. L'objectif de ce projet de recherche est de modéliser et contrôler un robot parallèle à câbles dédié à la rééducation des membres inférieurs. Pour y parvenir, nous avons d’abord établi les modèles cinématiques et dynamiques. Ensuite, pour le suivi de trajectoire dans l’espace cartésien, nous avons résolu le problème de la cinématique directe pour ce robot parallèle en utilisant la méthode numérique de Newton-Raphson. Après, deux contrôleurs basés sur les méthodes du couple calculé et du mode de glissement ont été conçus et mis en oeuvre. Enfin, un algorithme d'estimation en ligne a été mis en oeuvre avec le contrôleur afin de maintenir les tensions dans les câbles positives pendant le mouvement du robot, ce qui est nécessaire pour la commande des robots à câbles. Les méthodes développées ont été validées avec succès en simulation et les résultats ont montré de bonnes performances

Portuguese honeys as antimicrobial agents against Candida species

Background and aim Honey has been recognized worldwide for its antioxidant, anti-tumor, anti-inflammatory and antimicrobial properties. Among them, the antifungal properties associated to honey make it an attractive alternative treatment for Candida-associated infections, particularly for topical application to the mucous membranes and skin. In this sense, the main purpose of this work was to evaluate physicochemical properties of five Portuguese honeys and Manuka honey (an Australian honey with well recognized medical proprieties, used as control) and to evaluate the antifungal activity in Candida species planktonic and biofilm assays. Experimental procedure Pollen analysis, pH determination, color, concentration of protein and methylglyoxal, conductivity, total phenolics and flavonoids, hydrogen peroxide concentration, and characterization by differential scanning calorimetry in honey samples were determined. Additionally, the effect of honeys on planktonic growth of Candida was initially evaluated by determination of the minimum inhibitory concentrations. Then, the same effect of those honeys was evaluated in biofilms, by Colony Forming Units enumeration. Results and conclusion It has been shown that Portuguese heather (Erica cinereal) honey presented the most similar physicochemical properties to manuka honey (specially phenolic and flavonoids contents). The five Portuguese honeys under study, presented in general a potent activity against planktonic multi-resistant yeast pathogens (several clinical isolates and reference strains of Candida species) and S. aureus and P. aeruginosa bacteria cultures. Additionally, it was also concluded that Portuguese heather honey (50% and 75% (w/v)) can also act as a good Candida species biofilm reducer, namely for C. tropicalis.This study was supported by the Portuguese Foundation for Science and Technology (FCT), Portugal, under the scope of the strategic funding of UIDBB/04469/2020020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund, Portugal, under the scope of Norte 2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Antimicrobial activity and rutin identification of honey produced by the stingless bee Melipona compressipes manaosensis and commercial honey

Background: Honey has been identified as a potential alternative to the widespread use of antibiotics, which are of significant concern considering the emergence of resistant bacteria. In this context, this study aimed to evaluate the antimicrobial activity of honey samples produced by a stingless bee species and by Apis sp. against pathogenic bacteria, as well as to identify the presence of phenolic compounds.Methods: Honey samples from the stingless bee M. compressipes manaosensis were collected twice, during the dry and rainy seasons. Three commercial honey samples from Apis sp. were also included in this study. Two different assays were performed to evaluate the antibacterial potential of the honey samples: agar-well diffusion and broth macrodilution. Liquid-liquid extraction was used to assess phenolic compounds from honey. HPLC analysis was performed in order to identify rutin and apigenin on honey samples. Chromatograms were recorded at 340 and 290 nm.Results: Two honey samples were identified as having the highest antimicrobial activity using the agar diffusion method. Honey produced by Melipona compressipes manaosensis inhibited the growth of Staphylococcus aureus, Escherichia coli (0157: H7), Proteus vulgaris, Shigella sonnei and Klebsiella sp. A sample of honey produced by Apis sp. also inhibited the growth of Salmonella paratyphi. The macrodilution technique presented greater sensitivity for the antibacterial testing, since all honey samples showed activity. Flavonoid rutin was identified in the honey sample produced by the stingless bee.Conclusions: Honey samples tested in this work showed antibacterial activity against Gram-positive and Gram-negative bacteria. The results reported herein highlight the potential of using honey to control bacterial growth. © 2013 Pimentel et al.; licensee BioMed Central Ltd

Managing a fragmented XML data cube with oracle and timesten

International audienc

Modèle multidimensionnel d'objets complexes. Du modèle d'objets aux cubes d'objets complexes

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A Layered Multidimensional Model of Complex Objects

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