Conception, réalisation et caractérisation d'inductances planaires à couches magnétiques

Ce travail de thèse concerne la miniaturisation et l intégration de composants magnétiques comme les inductances utilisées dans les convertisseurs DC-DC et les circuits haute fréquence. Cette thèse a pour objectifs : - de développer une méthodologie d étude des inductances à couches magnétiques - de montrer la faisabilité de tels composants utilisant des couches épaisses de ferrite (50 à 500 m). Le contenu de notre document s articule ainsi autour de trois axes : la simulation, la réalisation et la caractérisation. En simulation, le logiciel HFSS, nous a permis de concevoir, de prédire le comportement du composant et d'étudier l influence des différents entrefers et épaisseurs du matériau magnétique. La réalisation fait appel aux différentes et nombreuses étapes micro technologiques qui sont décrites en détail. Ces étapes concernent les techniques de dépôt sous vide, les procédés de photolithographie, les techniques de dépôt électrolytique, les techniques de sciage et de collage. Enfin, la caractérisation des inductances réalisées a été effectuée en basses, moyennes et hautes fréquences respectivement au LCR mètre (20Hz à 1MHz), à l impédance mètre (40Hz à 110MHz) et à l analyseur vectoriel de réseaux (10MHz à 67GHz)This thesis concerns the miniaturization and integration of magnetic components such as inductors used in DC-DC converters and high frequency circuits. This thesis aims to: - to develop a methodology for the study of magnetic layers inductors; - to show the feasibility of such components using thick layers of ferrite (50 to 500 m). The content of our document is structured around three axes: simulation, realization and characterization. In simulation, HFSS software allowed us to design, predict the behavior of the component and to study the influence of different air gaps and layers of magnetic material. The realization involves numerous and different micro technology steps which are described in detail. These steps are technical of vacuum deposition, photolithography processes, electroplating deposition techniques, techniques of sawing and sticking. Finally, the characterization of inductors achieved was done in low, medium and high frequencies respectively with a LCR meter (20Hz to 1MHz), an impedance meter (40Hz to 110MHz) and a vector network analyzer (10MHz to 67GHz)ST ETIENNE-Bib. électronique (422189901) / SudocSudocFranceF

Large scale analysis of routine dose adjustments of mycophenolate mofetil based on global exposure in renal transplant patients.

International audienceBACKGROUND: : We report a feasibility study based on our large-scale experience with mycophenolate mofetil dose adjustment based on mycophenolic acid interdose area under the curve (AUC) in renal transplant patients. METHODS: : Between 2005 and 2010, 13,930 requests for 7090 different patients (outside any clinical trial) were posted by more than 30 different transplantation centers on a free, secure web site for mycophenolate mofetil dose recommendations using three plasma concentrations and Bayesian estimation. RESULTS: : This retrospective study showed that 1) according to a consensually recommended 30- to 60-mg*h/L target, dose adjustment was needed for approximately 35% of the patients, 25% being underexposed with the highest proportion observed in the first weeks after transplantation; 2) when dose adjustment had been previously proposed, the subsequent AUC was significantly more often in the recommended range if the dose was applied than not at all posttransplantation periods (72-80% vs. 43-54%); and 3) the interindividual AUC variability in the "respected-dose" group was systematically lower than that in the "not respected-dose" group (depending on the posttransplantation periods; coefficient of variation %, 31-41% vs 49-70%, respectively). Further analysis suggested that mycophenolic acid AUC should best be monitored at least every 2 weeks during the first month, every 1 to 3 months between months 1 and 12, whereas in the stable phase, the odds to be still in the 30- to 60-mg*h/L range on the following visit was still 75% up to 1 year after the previous dose adjustment. CONCLUSION: : This study showed that the monitoring of mycophenolate mofetil on the basis of AUC measurements is a clinically feasible approach, apparently acceptable by the patients, the nurses, and the physicians owing to its large use in routine clinics

Ultrasound-modulated optical imaging using a powerful long pulse laser

Peer reviewed: YesNRC publication: Ye

Acousto-optical imaging using a powerful long pulse laser

Peer reviewed: YesNRC publication: Ye

Improvement of sensitivity of acousto-optical imaging using a powerful long pulse laser

Peer reviewed: YesNRC publication: Ye

Ultrasound-modulated optical imaging using a confocal Fabry-Perot interferometer and a powerful long pulse laser

Ultrasound-modulated optical imaging combines the good spatial resolution of ultrasonic waves (mm scale) and the spectroscopic properties of light to detect optically absorbing objects inside thick (cm scale) highly scattering media. Light propagating in a scattering medium can interact with an ultrasonic wave thereby being tagged by a frequency shift equal to the ultrasound frequency or its harmonics. In this paper, a confocal Fabry-Perot interferometer(CFPI) is used as a tunable spectral filter to detect selectively the ultrasound-tagged photons. The CFPI allows obtaining high spectral resolution (MHz scale) while maintaining a high light gathering power when compared to other spectroscopic devices of comparable resolution. The contrast between the tagged photons and the untagged photons can be further enhanced by cascading CFPI. Moreover, the fast response of the CFPI allows performing measurements within the speckle decorrelation time typically encountered in biomedical applications. In this paper, the use of a single-frequency laser emitting powerful optical pulses allows illuminating the scattering medium only during the transit time of the probing ultrasonic pulses. Consequently, the acoustic and the optical power are both concentrated in time to enhance the signal-to-noise ratio of the tehcnique while remaining below the biomedical safety limits. The detection of optically absorbing objects (mm size) inside 30- and 60-mm thick scattering media is presented.L\u2019imagerie optique modul\ue9e aux ultrasons combine la bonne r\ue9solution spatiale des ondes ultrasoniques (\ue0 l\u2019\ue9chelle du mm) et les propri\ue9t\ue9s spectroscopiques de la lumi\ue8re pour d\ue9tecter des objets optiquement absorbants \ue0 l\u2019int\ue9rieur de milieux \ue9pais (\ue0 l\u2019\ue9chelle du cm) \ue0 forte diffusion. La propagation de la lumi\ue8re dans un milieu diffusant peut interagir avec une onde ultrasonique, \ue9tant ainsi marqu\ue9e par un d\ue9calage de fr\ue9quence \ue9gal \ue0 la fr\ue9quence des ultrasons ou de leurs harmoniques. Pour le pr\ue9sent travail, on a utilis\ue9 un interf\ue9rom\ue8tre confocal de Fabry-Perot (ICFP) comme filtre spectral r\ue9glable pour d\ue9tecter s\ue9lectivement les photons marqu\ue9s par les ultrasons. L\u2019ICFP permet d\u2019obtenir une r\ue9solution spectrale \ue9lev\ue9e (\ue0 l\u2019\ue9chelle du MHz) tout en maintenant un pouvoir de convergence de la lumi\ue8re \ue9lev\ue9 comparativement \ue0 d\u2019autres dispositifs spectroscopiques ayant une r\ue9solution comparable. Le contraste entre les photons marqu\ue9s et les photons non marqu\ue9s peut \ueatre am\ue9lior\ue9 par des ICFP en cascade. De plus, la r\ue9ponse rapide de l\u2019ICFP permet de r\ue9aliser des mesures pendant le temps de d\ue9corr\ue9lation du speckle observ\ue9 typiquement dans des applications biom\ue9dicales. L\u2019utilisation d\u2019un laser \ue0 fr\ue9quence unique \ue9mettant des impulsions optiques puissantes permet d\u2019illuminer le milieu diffusant uniquement pendant le temps de transit des impulsions ultrasoniques de d\ue9tection. En cons\ue9quence, la puissance optique et la puissance acoustique sont toutes deux concentr\ue9es dans le temps afin d\u2019am\ue9liorer le rapport signal/bruit de la technique, tout en restant sous les limites de s\ue9curit\ue9 pour des applications biom\ue9dicales. On pr\ue9sente la d\ue9tection d\u2019objets optiquement absorbants (taille de l\u2019ordre du mm) \ue0 l\u2019int\ue9rieur de milieux diffusants de 30 et 60 mm d\u2019\ue9paisseur.Peer reviewed: YesNRC publication: Ye

Micro-confinement of bacteria into w/o emulsion droplets for rapid detection and enumeration

International audienceToday, rapid detection and identification of bacteria in microbiological diagnosis is a major issue. Reference methods usually rely on growth of microorganisms, with the drawback of lengthy time-to-result. The method provides global information on a clonal population that is known to be inhomogeneous relative to metabolic states and activities. Therefore, there may be a significant advantage of methods that allow characterisation of individual bacteria from a large population, both for test time reduction and the clinical value of the characterisation. We report here a method for rapid detection and real-time monitoring of the metabolic activities of single bacteria. Water-in-oil emulsions were used to encapsulate single Escherichia coli cells into picolitre (pL)-sized microreactor droplets. The glucuronidase activity in each droplet was monitored using the fluorogenic reporter molecule MUG (4-methylumbelliferyl- - d-glucuronide) coupled to time-lapse fluorescence imaging of the droplets. Such bacterial confinement provides several major advantages. (1) Enzymatic activities of a large number of single bacterium-containing droplet could be monitored simultaneously, allowing the full characterisation of metabolic heterogeneity in a clonal population. We monitored glucuronidase enzymatic activity and growth over ∼200 single bacteria over a 24-h period. (2) Micro-confinement of cells in small volumes allows rapid accumulation of the fluorescent metabolite, hence decreasing the detection time. Independent of the initial concentration of bacteria in the sample, detection of the presence of bacteria could be achieved in less than 2 h. (3) Considering the random distribution of bacteria in droplets, this method allowed rapid and reliable enumeration of bacteria in the initial sample. Overall, the results of this study showed that confinement of bacterial cells increased the effective concentration of fluorescent metabolites leading to rapid (2 h) detection of the fluorescent metabolites, thus significantly reducing time to numeration

Near-Fatal Multiple Organ Dysfunction Syndrome Induced by Plasmodium malariae

International audienc

Study Protocol: A Randomized Controlled Trial of Patient Navigation-Activation to Reduce Cancer Health Disparities

Abstract Background Cancer health disparities affecting low-income and minority patients are well documented. Root-causes are multifactorial, including diagnostic and treatment delays, social and financial barriers, and poor communication. Patient navigation and communication coaching (activation) are potential interventions to address disparities in cancer treatment. The purpose of this clinical trial is to test the effectiveness of an intervention combining patient navigation and activation to improve cancer treatment. Methods/Design The Rochester Patient Navigation Research Program (PNRP) is a National Cancer Institute-sponsored, patient-level randomized trial (RCT) of patient navigation and activation, targeting newly-diagnosed breast and colorectal cancer patients in Rochester, NY. The goal of the program is to decrease cancer health disparities by addressing barriers to receipt of cancer care and promoting patient self-efficacy. The intervention uses trained, paraprofessional patient navigators recruited from the target community, and a detailed training and supervisory program. Recruited patients are randomly assigned to receive either usual care (except for baseline and follow-up questionnaires and interviews) or intervention. The intervention patients receive tailored assistance from their patient navigators, including phone calls, in-person meetings, and behind-the-scenes coordination of care. A total of 344 patients have been recruited. Outcomes measured at three month intervals include timeliness of care, patient adherence, patient satisfaction, quality of life, self-efficacy, health literacy, and cancer knowledge. Discussion This unique intervention combining patient navigation and patient activation is designed to address the multifactorial problem of cancer health disparities. If successful, this study will affect the design and implementation of patient navigation programs. Trials Registration clinicaltrials.gov identifier NCT00496678http://deepblue.lib.umich.edu/bitstream/2027.42/78254/1/1471-2407-10-551.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78254/2/1471-2407-10-551.pdfPeer Reviewe