Th. licence--Droit--Paris, 1864-03-17.

Th. licence--Droit--Paris, 1869-08-12.

L’analyse protéomique par spectrométrie de masse s’est imposée comme une méthode incontournable pour la caractérisation des protéines. Grâce aux progrès de l’instrumentation et de la bioinformatique, l’interprétation automatisée des spectres MS/MS permet aujourd’hui d’identifier des milliers de protéines dans un type cellulaire. Cependant, cette méthodologie s’applique encore difficilement aux organismes dont les génomes n’ont pas été séquencés, et donc pour lesquels il n’existe pas de banques de séquences peptidiques de référence. Notre travail a porté sur le développement et l’application d’une méthodologie d’interprétation des données MS/MS pour les organismes à génomes non séquencés. Cette méthodologie est basée sur le séquençage de novo suivi de recherche MS-BLAST. Ainsi nous avons pu : Identifier les différents partenaires de complexes protéiques tels que les protéines des complexes TgGAP50, TgAlba, TgSORTLR impliqués dans la motilité, la virulence ou le trafic intracellulaire des protéines du parasite Toxoplasma gondii, Identifier et caractériser des variants d’hémoglobine humaine, Identifier les protéines différentiellement exprimées lors des interactions vigne et champignons à génomes non séquencés dans la maladie de l’esca, Caractériser finement la N-glycosylation de l’invertase vacuolaire du raisin. Nous avons pu réaliser nos études sur des échantillons d’origines très différentes : homme, plantes, champignons, parasites et nous avons apporté des éléments de réponses moléculaires aux questions biologiques. / The proteomic analysis by mass spectrometry is now an essential method for the characterization of proteins. Thanks to advances in instrumentation and bioinformatics, automated interpretation of MS/MS spectra can now identify thousands of proteins in a cell type. However, this methodology remains poorly applied to the organisms that genomes are not sequenced and therefore where there is no database of reference for peptides sequences. Our work has focused on the development and application of a methodology for the interpretation of MS/MS data for the organisms that genomes are not sequenced. This methodology is based on the de novo sequencing followed by MS-BLAST search. Thus we have: Identify different partners of protein complexes such as proteins TgGAP50, TgAlba and TgSORTLR complex, involved in motility, virulence or intracellular protein trafficking of Toxoplasma gondii, Identify and characterize human hemoglobin variants, Identify the proteins differentially expressed during interaction of vines and fungi that genomes are not sequenced in esca disease, Finely characterize the N-glycosylation of the grape vacuolar invertase. We have achieved our studies on samples of very different origins: human, plants, fungi, parasites, and we provided evidence of molecular responses to biological questions.

Le comportement en fluage et à la relaxation d’aciers au chrome est étudié par indentation instrumentée, ce qui permet de solliciter le matériau dans des conditions de chargement proches de celles des essais classiques. L’objectif principal n’est pas ici de se substituer à eux mais de proposer un classement des matériaux selon leur sensibilité en fluage / relaxation par indentation.Pour cela, nous déterminons, d’abord à température ambiante, les conditions optimales d’indentation en termes de temps de maintien, de charge de maintien, de vitesse de chargement et de forme de l’indenteur. La méthodologie proposée est appliquée ensuite à plus hautes températures jusqu’à 400 °C (limitation de l’instrument). A température ambiante, le coefficient de sensibilité à la contrainte obtenu correspond à la valeur extrapolée à température ambiante des données obtenues par fluage classique à hautes températures. Malheureusement, cette corrélation n’est pas vérifiée par indentation à chaud probablement à cause de la dérive thermique subie par l’instrument. Le comportement en relaxation par indentation a également été étudié à température ambiante. Nous proposons deux méthodes analytiques permettant de déterminer le coefficient d’homothétie défini dans la théorie de Hart. L’inverse de ce coefficient, déduit de la relaxation par indentation, est comparable au coefficient de sensibilité à la contrainte déterminé par fluage, ce qui permet de comparer les deux modes de sollicitation. Malgré les difficultés expérimentales rencontrées, nous proposons un classement des matériaux selon leur sensibilité au fluage. / The creep and relaxation behaviors of based-chromium steels are studied by instrumented indentation, which allows the application of loading conditions close to those of conventional tests to the material. The main objective here is not to substitute the classical tests by the indentation one, but to give a classification of materials according to their sensitivity in creep/relaxation by indentation.For that, we first determine at room temperature the optimum conditions of indentation in terms of holding time, indentation loading, the unloading and loading rates and indenter shape. The proposed methodology is afterwards applied at higher temperatures below 400 °C due to instrument limitation. At room temperature, we obtained the stress sensitivity exponent that corresponds to the extrapolated value at ambient temperature of data obtained by classical creep tests performed at high temperatures. Unfortunately, this correlation is not obtained by indentation at higher temperatures probably due to thermal drift of the instrument. We have also studied at room temperature the behavior in relaxation by indentation. We propose two analytical methods for determining the coefficient of scale defined in Hart's theory. The interest of this coefficient inferred from the relaxation by indentation is that its inverse is comparable to the stress sensitivity exponent determined by indentation creep, which allows to compare these two modes of solicitation. Despite the experimental difficulties encountered, we propose a classification of the tested materials according to their creep sensitivity.

Background: To describe the scoring methodology and MRI assessments used to evaluate the cross-sectional features observed in cases and controls, to define change over time for different MRI features, and to report the extent of changes over a 24-month period in the Foundation for National Institutes of Health Osteoarthritis Biomarkers Consortium study nested within the larger Osteoarthritis Initiative (OAI) Study. Methods: We conducted a nested case-control study. Cases (n = 406) were knees having both radiographic and pain progression. Controls (n = 194) were knee osteoarthritis subjects who did not meet the case definition. Groups were matched for Kellgren-Lawrence grade and body mass index. MRIs were acquired using 3 T MRI systems and assessed using the semi-quantitative MOAKS system. MRIs were read at baseline and 24 months for cartilage damage, bone marrow lesions (BML), osteophytes, meniscal damage and extrusion, and Hoffa- and effusion-synovitis. We provide the definition and distribution of change in these biomarkers over time. Results: Seventy-three percent of the cases had subregions with BML worsening (vs. 66 % in controls) (p = 0.102). Little change in osteophytes was seen over 24 months. Twenty-eight percent of cases and 10 % of controls had worsening in meniscal scores in at least one subregion (p < 0.001). Seventy-three percent of cases and 53 % of controls had at least one area with worsening in cartilage surface area (p < 0.001). More cases experienced worsening in Hoffa- and effusion synovitis than controls (17 % vs. 6 % (p < 0.001); 41 % vs. 18 % (p < 0.001), respectively). Conclusions: A wide range of MRI-detected structural pathologies was present in the FNIH cohort. More severe changes, especially for BMLs, cartilage and meniscal damage, were detected primarily among the case group suggesting that early changes in multiple structural domains are associated with radiographic worsening and symptomatic progression.

A poetry manuscript.

n.b. A. scabra

n.b. A. scabra

Disputats, Linköpings universitet, 2008. / Findes også på internet (PDF-format): http://www.diva-portal.org/diva/getDocument?urn_nbn_se_liu_diva-10489-1__fulltext.pdf. På cd-rom: Supplerende materiale i PDF-format. Med litteraturhenvisninger.

<p> </p><div> <div> <div> <p> </p><div> <div> <div> <p> </p><div> <div> <div> <p>The current state of the art in biopotential recordings rely on radiative electromagnetic (EM) fields. In such transmissions, only a small fraction of this energy is received since the EM fields are widely radiated resulting in lossy inefficient systems. Using the body as a communication medium (similar to a ’wire’) allows for the containment of the energy within the body, yielding order(s) of magnitude lower energy than radiative EM communication. The first part of this work introduces Animal Body Communication for untethered rodent biopotential recording and for the first time this work develops the theory and models for animal body communication circuitry and channel loss. In vivo experimental analysis proves that ABC successfully transmits acquired electrocardiogram (EKG) signals through the body with correlation greater than 99% when compared to traditional wireless communication modalities, with a 50x reduction in power consumption. The second part of this work focusses on the analysis and design of an Electro-Quasistatic Human Body Communication (EQS-HBC) system for simultaneous sensing and transmission of biopotential signals. In this work, detailed analysis on the system level interaction between the sensing and transmitting circuitry is studied and a design to enable simultaneous sensing and transmission is proposed. Experimental analysis was performed to understand the interaction between the Right Leg-Drive circuitry and the HBC transmission along with the effect of the ADC quantization on signal quality. Finally, experimental trials proves that EKG signals can be transmitted through the body with greater than 96% correlation when compared to Bluetooth systems at extremely low powers. </p> </div> </div> </div> </div> </div> </div> </div> </div> </div>