Search results for "imagerie"
showing 10 items of 88 documents
Caractérisation quantitative de la pulvérisation de pesticides par imagerie
2015
In recent years, advances in plant protection have contributed considerably to increasing crop yields in a sustainable way. Easy to apply and rather inexpensive, pesticides have proven to be very efficient. However, when pesticides are applied to crops some of the spray may not reach the target, but move outside the intended spray area. This can cause serious economic and environmental problems. Most of the pesticides are applied using agricultural sprayers. These sprayers use hydraulic nozzles which break the liquid into droplets with a wide range of droplet sizes and velocities and determine the spray pattern. Small droplets are prone to wind drift, while large droplets can runoff from th…
Development of fluorescent platforms for the design of multifunctional compounds for in vitro and in vivo applications in molecular imaging
2018
The objective of this thesis was the development and evaluation of new molecular platformsfor optical fluorescence imaging applications. This work sought to develop new tools that caneasily be modified and adapted to the specific needs of the intended use. This is required asthe fluorophore will influence the final properties and should thus be incorporated beforestructural optimization of the selected agent rather than at the very end. Two main axes wereexplored; the use of BODIPYs for the development of trackable therapeutic agents that areprimarily intended for in vitro applications and the use of azaBODIPYs for the design of an invivo compatible fluorescent platform.In the first part tw…
A new reading of Bronze Age funerary structures in Mongolia through the analysis of their architectural elements, arrangement and form
2022
The archaeological landscape of Mongolia is marked by the presence of numerous funerary monuments (khirigsuurs) and engraved stelae (deer stones), erected by nomadic populations at the end of the Bronze Age. The first observations indicate great regularity in the choice and arrangement of the architectural and iconographic elements at the time when these structures were built. This regularity suggests the existence of shared traditions and social coherence between nomadic communities in a territory covering almost twice that of France. The data available today do not provide sufficient perspective to establish social models at the level of a province, and even less so at the scale of the co…
Porphyrines et tétraazamacrocycles dérivés du DOTA : association de deux ligands pour la chélation de métaux d'intérêt en imagerie médicale multimoda…
2012
The goal of my PhD thesis was to synthesize new molecules, which give access to heterobimetallic complexes with interesting properties for multimodal imaging. In this manuscript, several main points have been studied. The first part of this work concerns the synthesis and characterization of ligands. We describe here the synthesis of five new ligands based on the association of one porphyrin and one or several cyclen derivatives. Those ligands are water-soluble. During the synthesis, we have targeted improvements to our work and developed a new synthetic pathway, which allowed us to obtain one ligand incorporating a porphyrin, a cyclen derivative and a free amine function. This function cou…
Development of an imaging system dedicated to the acquisition analysis and multispectral characterisation of skin lesion
2011
Visual evaluation of cutaneous lesions is the analysis the most commonly performedby dermatologists. This diagnostic is mainly done by naked eye and is based on criterionsuch as the size, shape, symmetry but principally on colour of the lesions. However, thisanalysis is subjective because it depends on the practician experience and the acquisitionconditions. We propose in this dissertation (1) the development of a multispectralcamera specifically dedicated for dermatological use. This device is based on a filterwheel composed of interferential filters and a neural network-based algorithm, generatinga hyperspectral cube of cutaneous data. This setting combines advantage of both spectrophotom…
Design of molecular imaging and theranostic agents for the detection and targeted therapy of cancers
2020
Despite significant advances in cancer detection and treatment, cancer is now the second leading cause of death worldwide. The aim of this thesis project was to design and optimize imaging agents for the diagnosis and/or therapy of various cancers.The first axis of this thesis focused on the development of a bimodal PET/fluorescence imaging agent capable of targeting neurotensin NTS1 receptors overexpressed in certain cancers. PET imaging would allow efficient detection of tumors and their metastases, while fluorescence imaging would facilitate the evaluation of tumor margins during surgery. Several compounds were synthesized, labelled with gallium-68 and studied in preclinical studies in a…
Study of new tellurite glasses in the TeO2-ZnO-La2O3 (TZL) system for the manufacturing of mid-infrared multimaterial optical fibers and specialty op…
2023
This thesis work was carried out using tellurite glasses from the TeO2-ZnO-La2O3 (TZL) ternary diagram for optical fibers manufacturing. The choice to use this system is motivated by the ambition to improve the transmission of optical signals within oxide glasses for which absorption bands related to OH groups are present in the transparency window. A structural study is first carried out on these glasses by Raman spectroscopy in order to understand the influence of the composition on physicochemical properties (especially on optical and thermal properties) but also to estimate the ability of a vitreous matrix to reorganize when subjected to a thermal solicitation such as the preform-to-fib…
Neurophysiological mechanisms of motor imagery : effects of associated somatosensory stimulation
2018
Mental training, which involves mentally simulating an action without motor output, is an effective stimulus to improve the maximal voluntary contraction. If only the motor pathway is activated, an activation of the somatosensory cortex is observed despite the lack of afferent feedback. Indeed, the motor imagery task efficiency is based in part on an interaction between motor and sensory pathway. Thus, it’s seems reasonable to think that the addition of sensory afferent feedback during motor imagery could potentiate the motor imagery effects and thus improve motor performance. In our first study, we showed that the addition of somatosensory stimulation of Ia-afferents during a motor imagery…
Alignement moléculaire : caractérisation et application à la mesure de thermalisation ultra-rapide et au contrôle de génération d'harmoniques
2013
The thematic of this thesis is molecular alignment. The latter is a very important topic that opens the way toward a much more thin control of many phenomenons. So, we have developed a new measurement technique of the molecular alignment along one axis that permits to preserve the sign of alignment. This one is, like other measurement techniques developed by the team,based on the measurement of the refractive index variation induced by the molecular alignment.The technique developed then also permits the molecular alignment measurement, being also an application of it because it allows the third harmonic generation. In the last study, molecular alignment is implemented to show that it bring…
Etude et modélisation du comportement des gouttelettes de produits phytosanitaires sur les feuilles de vignes par imagerie ultra-rapide et analyse de…
2013
In the domain of vineyard precision spraying research, one of the most importantobjectives is to minimize the volume of phytosanitary products ejected bya sprayer in order to be more environmentally respectful with more effectivevine leaf treatments. Unfortunaltely, even if lot of works have been carriedout at a parcel scale, mainly on losses caused by drift, less works have beencarried out at the leaf scale in order to understand which parameters influencethe spray quality. Since few years, recent improvements in image processing,sensitivity of imaging systems and cost reduction have increased the interestof high-speed imaging techniques. Analyzing the behavior of droplets afterimpact with…