Dissertationen zum Thema „Imagerie à particules magnétiques“
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Billotey, Claire. „Etude des propriétés des nanoparticules magnétiques anioniques pour l' application au marquage cellulaire direct et la détection in vivo par imagerie par résonance magnétique“. Paris 7, 2003. http://www.theses.fr/2003PA077015.
Der volle Inhalt der QuelleWandelt, Burkhard. „Analyse de la formation des dépôts de particules lors d'un procédé d'ultrafiltration tangentielle : visualisation par imagerie à résonance magnétique nucléaire“. Toulouse, INPT, 1993. http://www.theses.fr/1993INPT029H.
Der volle Inhalt der QuellePedron, Swannie. „Ιmagerie mοléculaire utilisant des micrοparticules d'οxyde de fer pοur la détectiοn de l'inflammatiοn cardiaque (par Ιmagerie par Résοnance Μagnétique) et de l'inflammatiοn pulmοnaire (par Ιmagerie à Ρarticules Μagnétiques - ΙΡΜ οu ΜΡΙ)“. Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC419.
Der volle Inhalt der QuelleConventional imaging methods such as cardiac MRI and thoracic CT scans are commonly used for diagnosing cardiovascular and pulmonary diseases. However, they only identify functional and anatomical abnormalities, and detecting the inflammatory component involved in these pathologies remains challenging. In this thesis, we develop a new molecular imaging approach called "immunoMRI," which targets endothelial adhesion molecules involved in recruiting leukocytes to inflammatory sites. Using iron oxide microparticles conjugated with a VCAM-1 antibody (MPIO@αVCAM-1), we assessed the ability of immuno-MRI to specifically detect cardiac inflammation in vivo in animal models of septic cardiac dysfunction and experimental autoimmune myocarditis (EAM). We also compared the effectiveness of immuno-MRI in detecting cardiac inflammation to late gadolinium enhancement, which is used in clinical practice and considered the gold standard for myocarditis diagnosis. In the second part of this work, we developed the use of a new imaging device called "Magnetic Particle Imaging" (MPI), which detects iron oxide particles to create whole-body images without using ionizing radiation. Through models of sepsis and infectious respiratory disease, we demonstrated that MPI coupled with MPIO@αVCAM-1 is a rapid, sensitive, and non-invasive tool for detecting pulmonary inflammation. Our data provide the first evidence suggesting the potential future application of immuno-MRI and MPI for diagnosing inflammatory cardiac and pulmonary conditions
Babataheri, Avin. „Cils artificiels : modèle physique pour la propulsion ciliée“. Phd thesis, Paris 6, 2009. http://pastel.archives-ouvertes.fr/pastel-00566532.
Der volle Inhalt der QuelleDeviers, Alexandra. „Imagerie par résonnance magnétique multimodale, en particulier imagerie spectroscopique, du glioblastome : évaluation de facteurs prédictifs de réponse à la radiothérapie“. Toulouse 3, 2014. http://www.theses.fr/2014TOU30057.
Der volle Inhalt der QuelleGlioblastoma (GBM), the most common primary brain tumor in adults, is associated with poor prognosis as local relapse occurs several months after chemo-radiotherapy (RT). New therapeutic strategies are coming to the fore, some of which propose to use imaging biomarkers in order to provide relevant prognostic information or identify pre-RT high relapse risk areas needing to be boosted. The aim of this work was to identify pre-RT MRI markers able to predict relapse location and survival in a cohort of 18 GBM patients included in a phase II clinical trial and treated with RT and Tipifarnib. Data from 3D 1H-Magnetic Resonance Spectroscopic Imaging (3D-MRSI) and diffusion MRI were analysed using a voxel-based spatial comparison of baseline (pre-RT) and relapse images. Three relevant metabolic indices were thus identified: Lactate/N-Acetyl-Aspartate (NAA)> 0. 4; Choline (Cho)/Creatine >1. 63 and Cho/NAA >1. 12. The spatial distribution of these MRSI biomarkers is significantly associated with the site of relapse; furthermore, the magnitude of these metabolic disturbances seems to be correlated with early relapse. These interesting results should be validated in a larger cohort of GBM patients currently included in a prospective phase III clinical trial. The various techniques implemented in this work shall be used in this new study, not only for the evaluation of MRSI and MR diffusion biomarkers, but also for the analysis of perfusion and tensor diffusion imaging
Carletto, Philippe. „Structures et rhéologie d'une suspension de particules magnétiques“. Nice, 2001. http://www.theses.fr/2001NICE5608.
Der volle Inhalt der QuelleWe have studied and worked out a model which predicts the formation of structures obtained by application of a magnetic field on a Magneto-Rheological suspension (MR). This reversible aggregation is due to a magnetization of the particles, itself connected to a difference in permeability between the particles and the suspending fluid. Two forces intervene in this process : the force of magnetic interaction between the particles and the thermodynamic force. We determined experimentally the parameters characterizing the structures formed in unidirectional field (structure of columns) and in rotating field. In this last case one observes the formation of a periodic structure in parallel plans situated in the plan of rotation of the field. A theoretical model based on a minimization of energy allows finding quantitatively the observations obtained in unidirectional field. On the other hand, in rotating field, the agreement is quantitative only to decrease the energy of surface. During this study we put in evidence a new instability of collective rotation of the aggregates. The last part of my work consisted in measuring the shear moduli in the presence of various types of structure. We showed that for the same magnetic field, the shear moduli depended strongly on the structure. We also put in evidence a critical deformation bounding the passage between a regime of oscillation of the aggregates in a nonlinear regime of fragmentation-restructuration, we were able to find, by means of a model the critical shear observed for perpendicular plans in the shear
Prevot, Geoffrey. „Plateforme de nanoémulsions destinées au diagnostic et à la thérapeutique“. Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0195.
Der volle Inhalt der QuelleOil in water (O/W) nanoemulsions have been used for over 50 years in human clinics as a lipids source in parenteral nutrition. Even if nanoemulsions have recently emerged as vehicles for lipophilic active pharmaceutical ingredient (API) their use as a therapeutic or diagnostic agent is still under-exploited. The objective of this Ph.D thesis was to develop an nanoemulsions platform as an alternative to conventionally used nanosystems. In this work, 2 applications have been studied: the diagnosis of vulnerable plaque in atherosclerosis, and the treatment of Parkinson's disease. Nanoemulsions have been functionalized with humanized antibody targeting atheroma and loaded with magnetic particles as molecular contrast agents for magnetic resonance imaging (MRI) and an emerging technique: magnetic particle imaging (MPI). The successful plaque targeting has been demonstrated in atheromatous mice. The inclusion of original and ultra-bright lipophilic chromophores as well as the loading of API have paved the way to the development of multimodal and theranostic formulations. Therapeutic nanoemulsions against Parkinson’s disease have been developed to restore lysosomal pH of dopaminergic neurons with acidic polymer (PLGA). Acidification dysfunction leads to cell death due to the accumulation of waste inside neurons. The formulation has been optimized for brain delivery through intravenous or intranasal administration. The results show brain delivery in vivo trough intravenous injection associated with a pH rescue in vitro. The perspectives will focus on optimizing this platform and use it for new applications such as magnetic hyperthermia in cancers
Germain, Matthieu. „Applications des nanomatériaux en biologie : de l’encapsulation de cellules aux particules magnétiques“. Toulouse 3, 2006. http://www.theses.fr/2006TOU30136.
Der volle Inhalt der QuelleThe aim of our studies was to translate nanomaterials progresses in biological applications. The assembly of polyelectrolytes by electrostatic interactions leads to the formation of multilayer films with tunable properties. Here we have applied this technique for polyelectrolytes multilayer formation onto the surface of adherent mammalian cells. Polyelectrolytes properties allow a better control of molecule diffusion across the film and give new outlooks for cells encapsulation and its applications. Nanomaterials were also used for the elaboration of two kinds of composite capsules: (liposome / reticulated polyelectrolytes) and (liposome / silica) capsules which present a better stability and allow a more efficient control of their permeability. In collaboration with the start-up Nanobiotix, magnetic nanoparticles activable by external magnetic field and specifically targeted against tumoral cells have been designed, leading to new development of nanotechnologies in physical anticancer therapies
Chong, Céline. „Élaboration de particules de polymère magnétiques multifonctionnelles pour la préparation d'échantillons biologiques“. Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10333/document.
Der volle Inhalt der QuelleThis thesis describes the synthesis of magnetic latexes which are able to capture and release various microorganisms via non-specific and electrostatic interactions. Cationic iron oxide nanoparticles stabilized by nitrate counterions were synthesized by the co-precipitation of iron salts in water. The surface of the asobtained maghemite was then modified by a sol-gel process using a methacrylate-functionalized organosilane, in order to incorporate the iron oxide nanoparticles into latex particles by copolymerization reactions. Magnetic particles were obtained by dispersion, emulsion or miniemulsion polymerization of styrene or methyl methacrylate, performed in the presence of iron oxide. Due to the interaction between the stabilizers and iron oxides, dispersion polymerization was not a suitable approach. On the other hand, (mini-)emulsion polymerization led to a large range of particle diameters (140 – 650 nm), according to the process used to disperse iron oxides prior to the polymerization. These latexes contained between 2 and 37 % of magnetic particles, incorporating up to 91% of iron oxide. But the size distribution remained quite broad in all cases. The functionalization of the as-prepared magnetic particles was then undertaken by the introduction of either a charged co-monomer or polyelectrolytes or polyampholytes reactivable during the polymerization process. These kinds of polymers were synthesized by RAFT polymerization. Their ability to capture and release microorganisms was tested on silica-based model systems. Polyampholytes displayed good results on several microorganisms
Datta, Subhadeep. „Propriétés de transport électronique de nanotubes de carbone remplis de particules magnétiques“. Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENY008.
Der volle Inhalt der QuelleCarbon Nanotubes at low temperature behave as Quantum Dots for which charging processes become quantized, giving rise to Coulomb Blockade depending upon the coupling to the leads. Any small change in the electrostatic environment (tuned by the gate electrode) can induce shift of the stability diagram (so called Coulomb Diamonds) of the device, leading to conductivity variation of the Quantum Dot. A carbon nanotube can therefore be a very accurate electrometer. For example, if a magnetic system is electronically coupled to a nanotube, its electron conduction may be influenced by the spin state of the magnetic system (magneto- Coulomb effect). In this thesis, we report on the electrical transport measurements of such hybrid systems where a carbon nanotube is filled with magnetic nanoparticles such as Iron(Fe). We find that low-temperature (~40mK) current-voltage measurements of such devices can show a hysteretic behaviour in conductance with sharp jumps at certain magnetic fields. We explain the results in terms of the magneto-Coulomb effect where the spin flip of the iron island at non-zero magnetic field causes an effective charge variation in the Nanotube due to the Zeeman energy. Our studies are a step forward towards the study of the magnetic anisotropy of individual nanoparticles. We believe our findings have important implications for sensitive magnetic detectors to study the magnetization reversal of individual magnetic nanoparticle or molecule, even weakly coupled to a carbon nanotube
Zaloylo, Guy. „Etude et conception d'un dispositif de détection de fines particules métalliques“. Nancy 1, 1992. http://docnum.univ-lorraine.fr/public/SCD_T_1992_0037_ZALOYLO.pdf.
Der volle Inhalt der QuelleGay, Benoît. „Caractérisation de milieux diffusants chargés en particules par imagerie polarisée“. Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0111/these.pdf.
Der volle Inhalt der QuelleLa caractérisation de milieux semi-transparents à l’aide de méthodes non-intrusives présente un grand intérêt pour de nombreux défis technologiques et scientifiques. L’idée du présent travail est de sonder un milieu diffusant chargé en particules, à partir d’une source radiative externe, en analysant les distributions spatiale 2D des états de polarisation des radiations émergentes. La taille, la fraction volumique ainsi que la morphologie des particules, qui influencent des propriétés radiatives du milieu, sont examinées. Plus particulièrement, des agrégats fractals sont considérés de part leur grande importance dans de nombreux domaines. Une configuration originale d’imagerie polarisée est conçue pour révéler des effets de diffusion multiple. Ainsi un dispositif expérimental et un modèle correspondant ont été mis en oeuvre. Ce dernier est une partie clé pour comprendre les phénomènes intervenants. La signature en polarisation sous forme d’images est modélisée à partir du formalisme de Stokes qui permet de rendre compte du transfert radiatif polarisé. Le problème est résolu à partir d’une méthode d’intégration de Monte Carlo, qui permet une interprétation physique des motifs de polarisation observés. La méthode est appliquée à des suspensions aqueuses de polystyrène qui peuvent être utilisées dans des processus d’agrégation. La question de la modélisation de l’agrégation est discutée en termes de nécessité d’utilisation de morphologies complexes et de compositions réalistes (moyenne sur l’orientation, la configuration spatiale et la dispersion de taille). Pour ce faire, les effets de diffusion multiple intra et inter particules sont pris en compte. La sensibilité de la méthode au processus d’agrégation et à des paramètres morphologiques est discutée
Iqbal, Muhammad. „Préparation de particules submicroniques pour applications théranostiques : imagerie et thérapie“. Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10227/document.
Der volle Inhalt der QuelleThe objective of this study was to prepare and characterize multifunctional submicron particles that can be used for diagnosis and therapy of several fatal diseases including cancer (i.e theranostic). For this purpose, a systematic study was performed in order to optimize the process parameters for preparation of polymeric particle that can be used as a platform for effective delivery of drugs and imaging labels. The imaging agent (FluoSpheres®) was encapsulated via double emulsion solvent evaporation technique to be used fluorescent contrast agent and their in vitro evaluation was performed. Then, gold nanoparticles were prepared by using NaBH4 reduction method, characterized and encapsulated by polycaprolactone polymer for in vitro applications. Finally, the gold nanoparticle were loaded into polycaprolactone particle along with a hydrophilic drug (Nefopam) and a hydrophobic drug (benzyl benzoate) simultaneously. The prepared particles were then characterized physicochemically and in vitro skin penetration study was performed
Delestre, Barbara. „Reconstruction 3D de particules dans un écoulement par imagerie interférométrique“. Electronic Thesis or Diss., Normandie, 2022. http://www.theses.fr/2022NORMR116.
Der volle Inhalt der QuelleFor many industrial or environmental applications, it is important to measure the size and volume of irregularly shaped particles. This is for example the case in the context of aircraft icing which occurs during flights, where it is necessary to measure in situ the water content and the ice content in the troposphere in order to detect and avoid risk areas. Our interest has been on interferometric out-of-focus imaging, an optical technique offering many advantages (wide measurement field, extended range of sizes studied [50 μm: a few millimeters], distance particle / measuring device several tens of centimeters ...). During this thesis, we showed that the 3D reconstruction of a particle can be done from a set of three interferometric images of this particle (under three perpendicular viewing angles). This can be done using the error reduction (ER) algorithm which allows to obtain the function f(x,y) from the measurements of the modulus of its 2D Fourier transform |F(u,v)| , by reconstructing the phase of its 2D Fourier transform. The implementation of this algorithm allowed us to reconstruct the shape of irregular particles from their interferometric images. Experimental demonstrations were carried out using a specific assembly based on the use of a micro-mirror array (DMD) which generates the interferometric images of programmable rough particles. The results obtained are very encouraging. The volumes obtained remain quite close to the real volume of the particle and the reconstructed 3D shapes give us a good idea of the general shape of the particle studied even in the most extreme cases where the orientation of the particle is arbitrary. Finally, we showed that an accurate 3D reconstruction of a "programmed" rough particle can be performed from a set of 120 interferometric images
Nodot, Émilie. „Détection et caractérisation d'objets anthropiques par méthodes géophysiques et en particulier par méthode magnétique“. Electronic Thesis or Diss., Strasbourg, 2014. http://www.theses.fr/2014STRAH019.
Der volle Inhalt der QuelleLast three wars have left millions of tons of unexploded ordnance (UXO) in French subsoil. They put the population and the environment at risk. Geophysics and particularly the magnetic methods present some solutions to characterise and locate those generally magnetised objects. The multi-sensor magnetic cartography device designed at EOST has some faults. Consequently, (i) the production of a new digitizer, (ii) the acquisition of a new geo-spatial positioning system and (iii) the use of an extra sensor to correct the time-related variations of the magnetic field allow us to improve our cartography quality. Likewise, multi-altitude measurement allow us to optimise the time in relation to the wanted cartography definition. According to the approximation generally used in magnetism theory, the anomaly is insignificant compared to the regional magnetic field. At the same time as my previously described field work, a thorough study of the dipole theory, allowed me to evaluate that this approximation results in a non-negligible mistake reaching 16% of the anomaly. The inversion results are sensible to this mistake. Moreover, l've developed an algorithm based on Euler deconvolution and l've re-evaluated the method already used which is based on analytic signal. After I compared some of the inversion methods, the one based on the analytic signal seems to ascertain the better the object characteristics
Faucon, Adrien. „Nanomatériaux moléculaires fluorescents et magnétiques pour la bio-imagerie multi-échelle“. Nantes, 2014. http://archive.bu.univ-nantes.fr/pollux/show.action?id=19e2fb12-75a7-4527-a030-3b8b6c2acd4a.
Der volle Inhalt der QuelleThe aim of this PhD work deals with the development, the structural and physico-chemical characterizations of nanomaterials which can combine emission properties after excitation using one or two photons, and magnetism. The association of these two distinct properties, fluorescence and magnetism, allowed us to obtain bimodal functional materials. Over the past years, this kind of nano-objet has raised a large interest in bio-imaging, cancer treatment using hyperthermia, as well as in optical data storage. The bimodal nanomaterials are elaborated by self-assembling iron oxide nanoparticles with small organic fluorophores able to form nanospheres upon nano-precipitation, yielding core-shell nanoassemblies. The development and studies of organic nano-objects, based on small molecules, represent an expanding field, mainly due to the high density of active units. To the best of our knowledge, this tight non-covalent association between a non-doped fluorescent core and a shell composed of iron oxide nanoparticles has never been studied. Before using such magneto-fluorescent nanoassemblies, several studies have to be performed in order to fully understand and characterize the photophysical properties of the fluorophores in solution as well as in the solid state. After a stabilization process compatible with physiological conditions, the resulting nanoassemblies will be used for in vitro and in vivo bioimaging studies. The studies of the biodistribution and the possible degradation of the assemblies will also be performed
Cros, Ghislaine. „Exploitation des propriétés magnétiques du sang en IRM : veinographie, imagerie fonctionnelle“. Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10219.
Der volle Inhalt der QuelleBenadjal, Youb. „Recherche de monopôles magnétiques auprès du détecteur du Fréjus“. Montpellier 2, 1989. http://www.theses.fr/1989MON20189.
Der volle Inhalt der QuelleNaud, Cécile. „Particules magnétiques pour le traitement du cancer par effet magnéto-mécanique, application au glioblastome“. Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAS005/document.
Der volle Inhalt der QuelleGlioblastoma is a brain cancer with a very poor prognosis. Existing therapies improve only slightly the median survival. In this work, we study a new treatment by magneto-mechanical actuation of particles (TMMAP). A low frequency (20 Hz) rotating magnetic field is applied to stimulate magnetic particles localized near cancer cells. Magnetic particles are produced by a top-down approach in clean room. Permalloy disks with a vortex configuration have a low remanence and are well dispersed in suspension. Multilayers of Co/Pt with a perpendicular anisotropy and permalloy vortex particles with an ellipse shape are also studied. TMMAP efficiency is tested in-vitro on glioblastoma cell line and the parameters are optimized. A huge diminution of living cells and an affected behavior of the remaining cells are observed after treatment. TMMAP is then adapted to an in-vivo study on glioblastoma orthotopic model on nude mice and the intratumoral injection of the particles is developed. Few differences are observed between tissues submitted to TMMAP or injected with particles, and survival is slightly increased. To mimic mechanical properties of the brain in a more relevant model, an in-vitro 3D model is proposed and validated. Based on cells grown as a spheroid and encapsulated in an agarose gel, this model brings optimization tracks
Leulmi-Pichot, Selma. „Destruction de cellules cancéreuses par vibrations magnéto-mécaniques de micro/nano particules magnétiques : Elaboration des particules par approche top-down, biofonctionnalisation et tests in-vitro“. Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY063/document.
Der volle Inhalt der QuelleIn the coming years, the treatment of serious diseases (cancer, brain diseases, etc.) could benefit more intensely from advances in materials science and nanotechnology. From the medical point of view, it is well known that cancer cells tend to develop resistance to chemotherapy, and the side effects encountered seriously limit the effectiveness of treatments. For these reasons, the search for alternative therapies that target cancer cells without affecting healthy tissues is currently one of the most active areas of research on cancer. In this context, magnetic nanoparticles are receiving an increasing interest in a variety of applications ranging from biomedical diagnostic to targeted treatments. Indeed, due to their remote actuation by external magnetic fields, the magnetic particles have the ability to locally perform actuations on targeted biological species.This thesis describes an approach based on interfacing cancer cells with bio-functionalized magnetic particles. When these particles are bound to the cancer cells, applying an external alternating magnetic field induces the particles oscillations, which then transmits a mechanical stress to the cancer cells.For this application, specific magnetic particles were prepared. Unlike conventional magnetic particles made by chemical routes ("bottom-up"), the particles studied in this thesis have been specially designed by techniques used in micro / nanoelectronics ("top-down"). Thus, two types of magnetic particles were compared; synthetic antiferromagnetic particles (SAF) consisting of magnetic multilayer stacks and microparticles consisting of a single magnetic layer with a magnetic vortex configuration.Once these particles released in a solution, the self-polarization phenomenon that contributes to the agglomeration / dispersion of these particles by magnetostatic interactions were compared for both types of particles as well as the mechanical torques that they can exert on cancer cells when subjected to an external magnetic field.Although SAF particles generate higher torques, finding biocompatible materials that may replace the constituents of the magnetic stack remains difficult, while vortex-particles would be easier to make in magnetic iron oxides.By exploiting the properties of NiFe magnetic vortices, we have developed an approach for the targeted destruction of the human renal carcinoma cells. The tests launched in vitro show that the magneto-mechanical stimulus creates two dramatic effects: a significant decrease in the rate of alive cancer cells, and the initiation of the apoptosis (programmed cell death). These results were achieved by applying low field values (~ 100 Oe i.e.10mT) at low frequencies (~ 20 Hz). Studies for the quantification of cell death by flow cytometry were conducted. The results already obtained even at the stage of "proof of Concept" are very encouraging for new perspectives of cancer therapies
Génot, Vincent Nathanaël. „Etude des phénomènes d'accélération de particules dans les régions aurorales des magnétosphères“. Versailles-St Quentin en Yvelines, 1999. http://www.theses.fr/1999VERS0011.
Der volle Inhalt der QuelleRigal, Claire. „Comportement de fluides complexes sous écoulement : approche expérimentale par résonance magnétique nucléaire et techniques optiques et simulations numériques“. Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0091/document.
Der volle Inhalt der QuelleThis thesis is an experimental and numerical study of structured fluids bidimensional flows in a cylindrical pipe with singularity and in an annular geometry with eccentric cylinders. The objective of this thesis is to characterize the influence of the shear thinning properties on the recirculation zones by using efficient and non-intrusive techniques: particle image velocimetry and velocimetry by nuclear magnetic resonance imaging. Materials are xanthane solutions at different concentrations. In the first part, we determine the rheological and viscoelastic properties of the fluids used. The second part concerns the measured velocity field. It is shown that the shear thinning behavior have a strongly influence on the structure and the morphology of these flows and the pattern of the recirculation zones. Simultaneously, numerical simulations performed by Fluent and using the rheological behavior. A good concordance is observed between the experimental and numerical results. For the flows considered here, this comparison allows to validate the computational code and the behavior law used in the numerical simulations and modelling by a Cross model
Roullier, Victor. „Micelles de nanocristaux fluorescentes et magnétiques comme sondes pour la bio-imagerie“. Rennes 1, 2009. http://www.theses.fr/2009REN1S159.
Der volle Inhalt der QuelleWe report the synthesis of both fluorescent and magnetic nanoprobes for labelling and tracking individual biomolecules by bio-imaging (fluorescence microscopy, MRI, …). Both fluorescent semi-conductors (quantum dots) and magnetic (iron oxide) nanocristals were co-encapsulated by using amphiphiles which self-organise into stable micelles with a diameter of 18 to 30 nm. These amphiphiles (PEGylated gallates) present 3 undecanoyl chains, a 34 units polyethylene glycol (PEG) and a terminal functional group such as : OH, NH₂, COOH or N₃. The magnetic properties of the micelles permit to guide them collectively under magnetic field. Furthermore, effect on the contrast in MRI was quantified. Finally, recognition groups such as biotin (targeting avidin derivatives) or tris-NTA (targeting polyhistidine tag by complexation with Ni²⁺) were introduced. We achieved a specific and selective labelling of transmembranar proteins onto HeLa cells, using tris-NTA
Nodot, Émilie. „Détection et caractérisation d'objets anthropiques par méthodes géophysiques et en particulier par méthode magnétique“. Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAH019/document.
Der volle Inhalt der QuelleLast three wars have left millions of tons of unexploded ordnance (UXO) in French subsoil. They put the population and the environment at risk. Geophysics and particularly the magnetic methods present some solutions to characterise and locate those generally magnetised objects. The multi-sensor magnetic cartography device designed at EOST has some faults. Consequently, (i) the production of a new digitizer, (ii) the acquisition of a new geo-spatial positioning system and (iii) the use of an extra sensor to correct the time-related variations of the magnetic field allow us to improve our cartography quality. Likewise, multi-altitude measurement allow us to optimise the time in relation to the wanted cartography definition. According to the approximation generally used in magnetism theory, the anomaly is insignificant compared to the regional magnetic field. At the same time as my previously described field work, a thorough study of the dipole theory, allowed me to evaluate that this approximation results in a non-negligible mistake reaching 16% of the anomaly. The inversion results are sensible to this mistake. Moreover, l've developed an algorithm based on Euler deconvolution and l've re-evaluated the method already used which is based on analytic signal. After I compared some of the inversion methods, the one based on the analytic signal seems to ascertain the better the object characteristics
Fromen, Marie-Claire. „Etude expérimentale et modélisation de la structure de nanoparticules magnétiques : des particules isolées aux assemblages“. Phd thesis, INSA de Toulouse, 2003. http://tel.archives-ouvertes.fr/tel-00003695.
Der volle Inhalt der QuelleTrévisan, Marie. „Biofonctionnalisation, caractérisation et mise en oeuvre de particules magnétiques sur biocapteurs : application au génotypage plaquettaire“. Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00713534.
Der volle Inhalt der QuelleDarud, Véronique. „Relations synthèse-structure-propriétés de polyuréthannes linéaires susceptibles d’être utilises comme liant de particules magnétiques“. Lyon, INSA, 1988. http://www.theses.fr/1988ISAL0073.
Der volle Inhalt der QuelleDesaubry, Christophe. „Conception de deux dispositifs expérimentaux pour la vélocimétrie par imagerie de particules : Application aux écoulements basse vitesse“. Lyon, INSA, 1995. http://www.theses.fr/1995ISAL0111.
Der volle Inhalt der Quelle[The study of heat transfer that appears in convective flows needs a very good knowledge of low velocity flow dynamic. The laser visualization is actually a technic witch is commonly used for qualitative flow description. Particle Image Velocimetry (P. I. V), recently developed, is derived from the proceeding technical. The P. I. V quantitative method allows to extract informations concerning two dimensionnal velocity field from a double-exposed image of the fluid in motion. Two experimental setups are described in this work. Both are based on the standard video catching technical and on numerical technical often used in P. I. V measurements. A systematic and comparative analysis of the two setups is made by considering different applications allowing several fluid flow mechanisms. ]
Piraux, Hélène. „Nanoparticules magnétiques : Vectorisation par la voie principale d'acquisition du fer : Elaboration et physico-chimie“. Paris 7, 2014. http://www.theses.fr/2014PA077219.
Der volle Inhalt der QuelleDue to their magnetic properties, iron oxide nanoparticles are widely used for their significant role in the diagnostic and treatment of cancer. One of the main challenges of magnetic nanoparticles in nanomedicine is their effective targeting, which consists of their fast and precis( delivery directly into destination cells. Transferrin is one of the two proteins involved in the major iron acquisition pathway. Indeed, via its interaction with Receptor 1, transferrin crosses the plasma membrane within few minutes by receptor-mediated endocytosis. Furthermore, the overexpression of transferrin-receptor 1 in cancer tells enhances transferrin internalization making it a perfect Trojan horse for nanoparticles delivery. In this work, 3 different sizes of maghemite nanoparticles (5, 10 and 15 nm) were synthetized by the polyol method, coated with 3-aminopropyltriethoxysilane and coupled to transferrin. For each size, the ratio of transferrin per nanoparticle was determined and the interaction in vitro with the receptor was investigated. Then a comparative study of internalization was conducted in cellulo between raw and grafted to transferrin nanoparticles. The efficiency of the targeting was analyzed by magnetophoresis and confocal fluorescence microscopy. All grafted nanoparticles were rapidly internalized in HeLa cells. Thus a relationship between the size of th( constructs and their efficacy in nanoparticles delivery was established. A comparison of our resuits with those of the literature shows a promising model for theragnostic devices
Villette, Carole. „Elaboration et caractérisation de fines particules de ferrites spinelles substitués (cuivre/cobalt/manganèse) : relations structure-propriétés magnétiques“. Toulouse 3, 1995. http://www.theses.fr/1995TOU30286.
Der volle Inhalt der QuelleBoyajian, Taline. „Etude et réalisation d'un circulateur hyperfréquence à nano particules magnétiques orientées dans la bande 40-60GHz“. Phd thesis, Université Jean Monnet - Saint-Etienne, 2011. http://tel.archives-ouvertes.fr/tel-00670799.
Der volle Inhalt der QuelleTomchuk, Bogdan. „Diffusion des particules transversalement au champ magnétique et diffusion exacerbée des ondes électromagnétiques“. Palaiseau, Ecole polytechnique, 2000. http://www.theses.fr/2000EPXX0006.
Der volle Inhalt der QuelleReithinger, Valérian. „Assurance qualité des traitements par hadronthérapie carbone par imagerie de particules promptes chargées“. Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10171/document.
Der volle Inhalt der QuelleHadrontherapy is an innovative radiotherapy modality in which light ions -such as protons or carbon ionsare accelerated to a relativistic speed and focused to irradiate a tumoral area. This technique differs from the conventional radiotherapy -which uses photons- by the existence of an energy deposition peak, called Bragg peak, which stands at the end of the ions path. However, different phenomena that lead to uncertainty in the real ion range exist, and limit the intrinsic accuracy of this modality. This justifies the need for a treatments quality assurance and motivates the development of in-line and real-time monitoring techniques to follow the real ions range. This PhD thesis work aims the characterization of an ion range monitoring technic, called interaction vertex imaging. It has been observed that during the ion path in the patient, a significant part of incoming ions undergoes nuclear reactions, causing a prompt secondary charged particles radiation. A telescope made up of pixelated sensors is proposed to locate these particles interaction vertex and to measure their correlation with the ions range, correlation predicted by a previous in-silico work. The first experimental results for this technique has been obtained with the realization of several experiments during which homogeneous and heterogeneous targets were irradiated under realistic conditions. Simulations were also performed to compare with experimental results. Before discussing the overall results, this manuscript details the hardware and software aspects of important developments that was made and that resulted in a complete and working prototype imager, with Monte Carlo simulations based on the Geant4 software
Mairesse, Fabrice. „Contrôle dimensionnel de panneaux de particules de grandes dimensions par traitement d’images“. Dijon, 2007. http://www.theses.fr/2007DIJOS074.
Der volle Inhalt der QuelleThis thesis deals with the dimensional control, in industrial conditions, of large manufactured particleboards. Two principal problematics were broached: the mosaicking due to acquisition conditions and the measure of distorted circular forms. For the first problematic, a solution based on interest points search by hessian matrix combined with a local characterization by Census transform was revealed as an efficient method. The second problematic, due to the crumbly nature of the material and obstructions by the coating, is the measure of imperfect edge drillings. In order to compensate distortions, a multi-scale approach by active contours was developed. This one gives, in one pass, a set of approximations of the initial outline around a global scale factor. More regularized outlines are then generated more or less close to the original form following a second scale parameter. The estimator of obtained circular forms characteristics is done with a new estimator based on the Radon transform. Circle's tangents allow to find the center and the radius. The method is based on an accumulation principle in discrete geometry and discretized parametric fitting, giving a subpixel precision. This new approach is more accurate than classical estimators in the framework of distorted circles
Grisollet, Alain. „Contribution à une étude multinucléaire ¹H, ² ³ Na, ³¹ P, sur une machine d'imagerie médicale par résonance magnétique à haut champ (1. 5 tesla)“. Paris 11, 1985. http://www.theses.fr/1985PA112302.
Der volle Inhalt der QuelleBoucard, Joanna. „Nanomatériaux magnéto-fluorescents pour la bio-imagerie multimodale et la libération contrôlée de principes actifs“. Thesis, Nantes, 2018. http://www.theses.fr/2018NANT4051/document.
Der volle Inhalt der QuelleThese PhD studies consist in the design and characterizations of theranostic nano-tools to meet two requirements. The first one is cell-targeted diagnostics (cancer and muscle cells, bacteria, macrophages) using nanomaterials detectable by fluorescence microscopy and MRI. The second aims at controlling the release of drugs, including anticancerous ones, encapsulated in nanomaterials. The nanometric size of these objects enables enhanced accumulation in tumor tissue (cells), thereby decreasing toxicity side-effects. These objects are supramolecular nanoassemblies composed of a fluorescent solvatochrom organic core coated by a shell of magnetic iron oxide nanoparticles. The emissive core, named FON for fluorescent organic nanoparticle, shows a bright redshifted emission signal compatible with the first biological tissue transparency window. FONs exhibit no cytotoxicity and little photobleaching. The ability of FONs to disassemble once internalized in cellulo and their hydrophobicity enable hydrophobic drugs vectorization. In this way, in cellulo drug delivery can be followed-up by fluorescence microscopy. Drug delivery can be controlled with magnetic hyperthermia thanks to the heating properties due to an alternative magnetic field applied to magnetic nanoparticles. Furthermore, magnetic nanoparticles allow tumor evolution to be monitored in vivo using MRI. All these combined properties pave the way toward theranostic potentialities where personalized nanomedicine is highly requested
Montagne, Franck. „Elaboration de latex magnétiques à partir d'émulsions directes de ferrofluide : forces de surface entre conjugués particules-oligodésoxyribonucléotides“. Lyon 1, 2002. http://www.theses.fr/2002LYO10241.
Der volle Inhalt der QuelleNoël, Céline. „Auto-structuration de particules magnétiques dans un cristal liquide nématique : vers un nouveau type de composite adaptatif“. Nice, 2005. http://www.theses.fr/2005NICE4059.
Der volle Inhalt der QuelleThis work is relative to the self-structuring of magnetic particles in a nematic liquid crystal (NLC) matrix. The elaboration of new materials, combining magnetic properties and particles structuring, is part of the full expansion field of the research of adaptive materials. P. Poulin, the first, reported on new colloidal interactions induced by the elasticity of a nematic suspending fluid. To obtain a controlled structuring of micronic particles by the nematic matrix, an accurate control of the anchorage of the NLC molecules on the iron particles surface is necessary. Thus, after a thorough characterization of the state of the iron surface, various treatments, which ensure a homeotropic anchoring of the nematogens in contact with that surface, have been realized on plates used as model system. Two approaches have been explored: the first consists in modifying the iron surface state, the other one, much more promising, consists in modifying the surface by deposition of amphiphilic molecules. These treatments, successfully transposed to the iron particles, allow us to obtain strong homeotropic anchorage. This is absolutely necessary to create the topological defects inducing the self-alignment of the particles. The magnetic response of the iron particles under external field, observed by optical microscopy, allows us to calculate precisely, thanks to a finite elements method of magnetic force calculation, both the repulsive and the attractive contributions to the force. Then the complete profile of this force, due to the distortions of the NLC around the particles, for the first time, is built
Perrier, Marine. „Elaboration de nanoparticules magnétiques à base de polymères de coordination cyano-ponté pour l'imagerie médicale“. Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20262/document.
Der volle Inhalt der QuelleThe goal of the present research is to elaborate new magnetic nanoparticles for medical imaging. This manuscript will describe the nanoparticles' synthesis method, their characterization and their evaluation as contrast agent for magnetic resonance imaging (MRI) and functional probe for scintigraphy.In a first time, we will propose synthesis processes allowing to obtain cyano-bridged coordination polymer based magnetic nanoparticles elaborated from transition metals or lanthanides molecular precursors using cyano-bridged ligands and stabilizing ligands soluble in water and biocompatible. We will introduce the synthesis, structural and textural characterizations and magnetic properties of these nano-objects with general formula My[M'(CN)6]z @stabilizer with M = Fe, Gd, Tb, Y, Ni, Cu ; M' = Fe, Co and stabilizer = PEG NH2, PEG400, Glu-TEG, D-Mannitol, NADG.In a second time, we will evaluate their potential as nanoprobles for application in medical imaging. For that, we will discuss about their capacity to act as a contrast agent for MRI and as a functional probe for scintigraphy or more specifically single photon emission computed tomography (SPECT). We will develop discussion about fundamental parameters which must be optimized to obtain contrast agent nano-objects for MRI and to understand nano-object relaxivity mechanisms. Then, we will test these contrast agents and functional probes in vitro and in vivo on mice. Also, we will evaluate the cytotoxicity, the kinetics and way of elimination, the biodistribution, the genotoxicity and the carcinogenesis of the used nanoparticles
Pillin, Béatrice. „Utilisation des champs magnétiques intenses pour la séparation d'inclusions : application aux particules solides immergées dans les métaux liquides“. Grenoble INPG, 1997. http://www.theses.fr/1997INPG0017.
Der volle Inhalt der QuelleBasly, Brice. „Conception et caractérisation de nano-objets magnétiques pour l’imagerie par résonance magnétique (IRM)“. Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/BASLY_Brice_2010.pdf.
Der volle Inhalt der QuelleFunctionalized iron oxide nanoparticles (NPs) have attracted an increasing interest as contrast agents for MRI. However, challenges remain to overcome: to optimize the functionalization of nanoparticles without affecting their magnetic properties while ensuring their biocompatibility and stealth in the human body, to prevent desorption of the grafted molecules under in vivo conditions, to ensure a small particle size distribution below 100 nm… In this context, we propose a novel strategy which involves the grafting, at the surface of NPs, of dendritic molecules (favoring the suspensions stability by steric hindrance and constituting a platform for the grafting of functional molecules) via a phosphonate coupling agent (allowing a direct grafting and a stronger binding) to develop innovative and competitive contrast agents. Thus, NPs with an average size of 10 nm were synthesized by two methods: co-precipitation and thermal decomposition. Three hydrophilic oligoethyleneglycol-based dendrons displaying a phosphonic acid at the focal point and three biocompatible chains (oligoethylene glycol) bearing functional groups such as COOH or NH2 were designed. The grafting conditions have been adapted according to the NPs and dendron natures. Numerous characterizations of the nanoparticles and their suspensions showed the preservation of the NPs magnetic and structural properties after the grafting step. Relaxivity measurements, in vivo tests and MRI measurements have shown the great potential of these dendronized nanoparticles for MRI
Ouldarbi, Lila. „Imagerie interférométrique en défaut de mise au point pour des mesures de particules discrètes en volume et la reconnaissance de forme de particules irrégulières“. Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR050/document.
Der volle Inhalt der QuelleSubmerged structures such as tidal turbines generate turbulent flows that can strongly disrupt the seabed. Understanding the impact of the presence of these structures requires understanding the three-dimensional dynamics of the vortices they generate. Optical methods, by their non-intrusive aspect, make it possible to analyze these dynamics. Interferometric Particle Imaging is a technique originally developed for the measurement of transparent spherical particles such as droplets orbubbles. We offer here an extension of this technique for the simultaneous characterization of irregular and spherical particles in a flow. A first experimental set-up has confirmed the validity of the method for the size and three-dimensional position measurement of grains of sand and air bubbles in water. A second device was used on a wave flume of bigger dimensions, introducing the notions of three-dimensional tracking of irregular particles and the analysis of the variation of their orientation.A third device made of two Interferometric Particle Imaging set-ups at two angles of observation is described for the shape recognition of different families of irregular particles. Through comparisons with simulations, dimensions and orientations of these particles are determined. This kind of device should be suitable for the characterization of ice crystals for which various shapes are known. The prospects that such results provide include the extension of the technique to the particle velocitymeasurement in hostile conditions, combined with the shape recognition and the determination of rotation of particles
Dulinski, Wojciech. „Conception et realisation d'un identificateur de particules a imagerie cerenkov pour le spectrometre lep-delphi“. Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13245.
Der volle Inhalt der QuelleDulinski, Wojciech. „Conception et réalisation d'un identificateur de particules à imagerie Cherenkov pour le spectromètre LEP-DELPHI“. Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37613319j.
Der volle Inhalt der QuelleTalbi, Mohamed. „Caractérisation morphologique de particules de glace par imagerie interférométrique multi-vues pour des applications aéroportées“. Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR070/document.
Der volle Inhalt der QuelleThe icing phenomenon that occurs during aircraft flights during their troposphere crossings (an area where the temperature can drop to -60 ° C) is manifested by an accretion of ice on different parts of the apparatus (wings, reactors, measurement probes ...) endangering the safety of this latter. This phenomenon is therefore a major problem for the safety of civil aviation, that's why it is necessary to develop new measurement techniques to detect and avoid risk's areas. Our interest has been on interferometric out-of-focus imaging, an optical technique offering many advantages (wide measurement field, range of studied sizes extended [50 μm: a few millimeters], distance particle / measuring device several tens of centimeters ...). During this thesis, we have developed a multi-view Interferometric Particle Imaging (IPI) device to characterize suspended ice crystals in the troposphere. Indeed, by comparison with measurements obtained on in-focus images recorded simultaneously, we have validated the use of multi-view IIP for the estimation of ice particle dimensions with an error rate lower than 20%. We also proposed different approaches to estimate ice particle volumes and highlighted the typical "signature" of a droplet during icing from IIP images.In a second part, we validated the use of multi-view IIP for the complex case where the interferograms of a pair of ice particles close to each other overlap and discuss about Moiré phenomena that may appear and disrupt our measurements. In addition, we have extended the field of use of IIP to less diluted media. Finally, in the last part, we have developed an innovative experimental device allowing us to perform experimental IIP measurements from particles "programmed" on a matrix of micro-mirrors (DMD : Digital Micromirror Device)
Chassaing, Isabelle. „Elaboration, caractérisation de fines particules et de couches minces de ferrites spinelles lacunaires cobalt-manganèse en vue de leur application à l'enregistrement magnéto-optique“. Toulouse 3, 1993. http://www.theses.fr/1993TOU30094.
Der volle Inhalt der QuelleBouard, Chloé. „Elaboration et caractérisation de systèmes magnétiques pour l'observation de skyrmions“. Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY084/document.
Der volle Inhalt der QuelleNew technology needs huge storage capacity together with high speed and low-cost transport of information. Current devices meeting their limits, research on new storage solutions is needed.One of them, proposed a few years ago, consists in using magnetic domain walls. Aligning them in nanowires and using the thickness of the layers could enable the realization of a tridimensional recording device and then improve the storage capacity.A new object more robust and less sensitive to perturbations has been discovered since. Skyrmion is now widely studied. It has been experimentally observed in two kinds of systems. The first one is helimagnet, with non centrosymmetric crystal structure. FeGe is one of them, with the highest critical temperature observed yet. Skyrmion has been observed as well at the interface between a heavy metal with strong spin-orbit coupling and a ferromagnet. In particular, multilayers with non-symmetric interfaces are very promising systems for manipulation of skyrmions at room temperature.Nevertheless, the elaboration of systems for industrial devices and reliable detection of skyrmions is still challenging. These two problematics are explored in this thesis, applied to two different systems. A protocol to grow helimagnetic FeGe thin films was first established, thanks to structural characterization mainly based on X-ray diffraction. Growth of multilayers with non symmetrical interfaces [heavy metal 1/ferromagnet/heavy metal 2]n was studied as well. These systems were then magnetically characterized, using numerous techniques such as magnetic imaging, magneto transport measurements and magnetic spectroscopy
Caro, Dominique De. „Synthèse et caractérisations physico-chimiques de petites particules métalliques en solution organique. Etude de leurs propriétés optiques et magnétiques“. Toulouse 3, 1995. http://www.theses.fr/1995TOU30231.
Der volle Inhalt der QuelleCajgfinger, Thomas. „Étude théorique et expérimentale du suivi de particules uniques en conditions extrêmes : imagerie aux photons uniques“. Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00770124.
Der volle Inhalt der QuelleCajgfinger, Thomas. „Etudes théorique et expérimentale du suivi de particules uniques en conditions extrêmes : imagerie aux photons uniques“. Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00999629.
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