Dissertations / Theses: 'Near infrared imagery'

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Costa, Posada Carlos Rufino. "The topographic effect in visible and near infrared satellite imagery." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624720.

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Roldan, Stephanie Marie. "Eye Movements and Hemodynamic Response during Emotional Scene Processing: Exploring the Role of Visual Perception in Intrusive Mental Imagery." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/86165.

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Unwanted and distressing visual imagery is a persistent and emotionally taxing symptom characteristic of several mental illnesses, including depression, schizophrenia, and posttraumatic stress disorder. Intrusive imagery symptoms have been linked to maladaptive memory formation, abnormal visual cortical activity during viewing, gaze pattern deficits, and trait characteristics of mental imagery. Emotional valence of visual stimuli has been shown to alter perceptual processes that influence the direction of attention to visual information, which may result in enhanced attention to suboptimal and generalizable visual properties. This study tested the hypothesis that aberrant gaze patterns to central and peripheral image regions influence the formation of decontextualized visual details which may facilitate involuntary and emotionally negative mental imagery experiences following a stressful or traumatic event. Gaze patterns and hemodynamic response from occipital cortical locations were recorded while healthy participants (N = 39) viewed and imagined scenes with negative or neutral emotional valence. Self-report behavioral assessments of baseline vividness of visual imagery and various cognitive factors were combined with these physiological measures to investigate the potential relationship between visual perception and mental recreation of negative scenes. Results revealed significant effects of task and valence conditions on specific fixation measures and hemodynamic response patterns in ventral visual areas, which interacted with cognitive factors such as imagery vividness and familiarity. Findings further suggest that behaviors observed during mental imagery reveal processes related to representational formation over and above perceptual performance and may be applied to the study of disorders such as PTSD.
Ph. D.

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Roth, Guy W., and n/a. "Agronomic measurements to validate airborne video imagery for irrigated cotton management." University of Canberra. Resource and Environmental Sciences, 1993. http://erl.canberra.edu.au./public/adt-AUC20050801.124927.

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Water is a major factor limiting cotton production and farmers must aim to optimise crop water use through timely irrigation scheduling decisions. Airborne video imagery when calibrated with a low density of ground based observations, offers the potential for near real time monitoring of crop condition, through sequential coverages of entire cotton fields. Using commercially available video equipment mounted on a light aircraft images were acquired of field experiments that were established in commercial cotton fields to test if the imagery could monitor changes in crop condition. Ground data collected from these experiments were used to evaluate green, red, near infrared and thermal band imagery for irrigated crop management. Prior to acquiring imagery, a ground radiometer study was conducted to investigate if canopy reflectance changed with the onset of crop water stress. Canopy reflectance decreased in the near infrared and green bands during the five day period prior to the crop's normal irrigation date. Red reflectance increased only after the crop irrigation was due, when the crop was suffering from water stress. The greatest change in canopy reflectance was in the near infrared region, attributable in part to a decrease in ground cover caused by canopy architectural changes including leaf wilting. The results of this experiment were used to select spectral filters for the video cameras. A range of crop conditions were identified in the imagery including; crop waterlogging, wheeltrack soil compaction, crop nitrogen status, different varieties, crop maturity, canopy development, soil moisture status, cotton yield and nutgrass weeds. Thermal imagery was the most successful for distinguishing differences in the crop soil moisture status. Near infrared imagery was most closely related to crop canopy development and is recommended for monitoring crop growth. Linear relationships were found between spectral responses in the imagery, crop reflectance (%) and crop temperature measured on the ground. Near infrared reflectance linearly increased, while spectral responses in the green, red and thermal bands exhibited an inverse relationship with plant height and ground cover. Imagery collected early in the season was affected by the soil background. Final lint yield was related to imagery in the red band. As the soil moisture level declined, crop temperature increased while reflectance in the green band decreased. To ensure an accurate relationship between soil moisture and thermal imagery, separate calibration equations are recommended for different stages in the season. Green, red and near infrared imagery were affected by the sun angle that caused one side of the imagery to appear brighter than the other. This problem was greatest in the green and red bands, but was not evident in the thermal imagery. Changes in solar radiation and air temperature on some occasions caused greater variation to the imagery between flights, than changes in crop condition per se. Therefore, it is not aIways possible to directly determine the soil moisture status from canopy temperature. Further research is required to correct imagery for environmental variables such as solar radiation, air temperature and vapour pressure deficit. Thermal imagery offers many improvements to current irrigation scheduling techniques including the facilitation of locating more representative ground sampling points. Thermal imagery also enables cotton fields on a farm to be ranked according to their soil moisture status. This then provides farmers with a visual picture of the crop water status across the whole farm, which is not possible using conventional ground scheduling techniques. At this stage, airborne video imagery will not replace soil moisture data collected for irrigation scheduling, however offers potential to enhance irrigation scheduling methods by addressing the problem of crop variability within cotton fields.

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Lange, Frédéric. "Développement d’un système de Topographie Optique Diffuse résolu en temps et hyperspectral pour la détection de l’activité cérébrale humaine." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI012.

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La Tomographie Optique Diffuse (TOD) est désormais une modalité d’imagerie médicale fonctionnelle reconnue. L’une des applications les plus répandues de cette technique est celle de l’imagerie fonctionnelle cérébrale chez l’Homme. En effet, cette technique présente de nombreux avantages, notamment grâce à la richesse des contrastes optiques accessibles. Néanmoins, certains verrous subsistent et freinent le développement de son utilisation, spécialement pour des applications chez l’Homme adulte en clinique ou dans des conditions particulières comme lors du suivi de l’activité sportive. En effet, le signal optique mesuré contient des informations venant de différentes profondeurs de la tête, et donc de différents types de tissus comme la peau ou le cerveau. Or, la réponse d’intérêt étant celle du cerveau, la réponse de la peau peut dégrader l’information recherchée. Dans ce contexte, ces travaux portent sur le développement d’un nouvel instrument de TOD permettant d’acquérir les dimensions spatiale, spectrale et de temps de vol du photon de façon simultanée, et ce à haute fréquence d’acquisition. Au cours de cette thèse, l’instrument a été développé et caractérisé sur fantôme optique. Ensuite, il a été validé in-vivo chez l’Homme adulte, notamment en détectant l’activité du cortex préfrontal en réponse à une tâche de calcul simple. Les informations multidimensionnelles acquises par notre système ont permis d’améliorer la séparation des contributions des différents tissus (Peau/Cerveau). Elles ont également permis de différencier la signature de la réponse physiologique de ces tissus, notamment en permettant de détecter les variations de concentration en Cytochrome-c-oxydase. Parallèlement à ce développement instrumental, des simulations Monte-Carlo de la propagation de la lumière dans un modèle anatomique de tête ont été effectuées. Ces simulations ont permis de mieux comprendre la propagation de la lumière dans les tissus en fonction de la longueur d’onde et de valider la pertinence de cette approche multidimensionnelle. Les perspectives de ces travaux de thèse se dirigent vers l’utilisation de cet instrument pour le suivi de la réponse du cerveau chez l’Homme adulte lors de différentes sollicitations comme des stimulations de TDCS, ou en réponse à une activité sportive
The Diffuse Optical Tomography (DOT) is now a relevant tool for the functional medical imaging. One of the most widespread application of this technic is the imaging of the human brain function. Indeed, this technic has numerous advantages, especially the richness of the optical contrast accessible. Nevertheless, some drawbacks are curbing the use of the technic, especially for applications on adults in clinics or in particular environment like in the monitoring of sports activity. Indeed, the measured signal contains information coming from different depths of the head, so it contains different tissues types like skin and brain. Yet, the response of interest is the one of the brain, and the one of the skin is blurring it. In this context, this work is about the development of a new instrument of DOT capable of acquiring spatial and spectral information, as well as the arrival time of photons simultaneously and at a high acquisition speed. During the PhD thesis the instrument has been developed and characterised on optical phantoms. Then, it has been validated in-vivo on adults, especially by detecting the cortical activation of the prefrontal cortex, in response to a simple calculation task. Multidimensional information acquired by our system allowed us to better distinguish between superficial and deep layers. It also allowed us to distinguish between the physiological signature of those tissues, and especially to detect the variations of concentration in Cytochrom-c-oxydase. Concurrently to this experimental work, Monte-Carlo simulation of light propagation in a model off a human head has been done. Those simulations allowed us to better understand the light propagation in tissues as function as their wavelength, and to validate the relevance of our multidimensional approach. Perspectives of this work is to use the developed instrument to monitor the brain’s response of the Human adult to several solicitations like tDCS stimulation, or sports activity

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Li, Kefeng. "Biometric person identification using near-infrared hand-dorsa vein images." Thesis, University of Central Lancashire, 2013. http://clok.uclan.ac.uk/9238/.

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Biometric recognition is becoming more and more important with the increasing demand for security, and more usable with the improvement of computer vision as well as pattern recognition technologies. Hand vein patterns have been recognised as a good biometric measure for personal identification due to many excellent characteristics, such as uniqueness and stability, as well as difficulty to copy or forge. This thesis covers all the research and development aspects of a biometric person identification system based on near-infrared hand-dorsa vein images. Firstly, the design and realisation of an optimised vein image capture device is presented. In order to maximise the quality of the captured images with relatively low cost, the infrared illumination and imaging theory are discussed. Then a database containing 2040 images from 102 individuals, which were captured by this device, is introduced. Secondly, image analysis and the customised image pre-processing methods are discussed. The consistency of the database images is evaluated using mean squared error (MSE) and peak signal-to-noise ratio (PSNR). Geometrical pre-processing, including shearing correction and region of interest (ROI) extraction, is introduced to improve image consistency. Image noise is evaluated using total variance (TV) values. Grey-level pre-processing, including grey-level normalisation, filtering and adaptive histogram equalisation are applied to enhance vein patterns. Thirdly, a gradient-based image segmentation algorithm is compared with popular algorithms in references like Niblack and Threshold Image algorithm to demonstrate its effectiveness in vein pattern extraction. Post-processing methods including morphological filtering and thinning are also presented. Fourthly, feature extraction and recognition methods are investigated, with several new approaches based on keypoints and local binary patterns (LBP) proposed. Through comprehensive comparison with other approaches based on structure and texture features as well as performance evaluation using the database created with 2040 images, the proposed approach based on multi-scale partition LBP is shown to provide the best recognition performance with an identification rate of nearly 99%. Finally, the whole hand-dorsa vein identification system is presented with a user interface for administration of user information and for person identification.

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Font, Aragonès Xavier. "Visible, near infrared and thermal hand-based image biometric recognition." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/117685.

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Biometric Recognition refers to the automatic identification of a person based on his or her anatomical characteristic or modality (i.e., fingerprint, palmprint, face) or behavioural (i.e., signature) characteristic. It is a fundamental key issue in any process concerned with security, shared resources, network transactions among many others. Arises as a fundamental problem widely known as recognition, and becomes a must step before permission is granted. It is supposed that protects key resources by only allowing those resources to be used by users that have been granted authority to use or to have access to them. Biometric systems can operate in verification mode, where the question to be solved is Am I who I claim I am? or in identification mode where the question is Who am I? Scientific community has increased its efforts in order to improve performance of biometric systems. Depending on the application many solutions go in the way of working with several modalities or combining different classification methods. Since increasing modalities require some user inconvenience many of these approaches will never reach the market. For example working with iris, face and fingerprints requires some user effort in order to help acquisition. This thesis addresses hand-based biometric system in a thorough way. The main contributions are in the direction of a new multi-spectral hand-based image database and methods for performance improvement. The main contributions are: A) The first multi-spectral hand-based image database from both hand faces: palmar and dorsal. Biometric database are a precious commodity for research, mainly when it offers something new like visual (VIS), near infrared (NIR) and thermography (TIR) images at a time. This database with a length of 100 users and 10 samples per user constitute a good starting point to check algorithms and hand suitability for recognition. B) In order to correctly deal with raw hand data, some image preprocessing steps are necessary. Three different segmentation phases are deployed to deal with VIS, NIR and TIR images specifically. Some of the tough questions to address: overexposed images, ring fingers and the cuffs, cold finger and noise image. Once image segmented, two different approaches are prepared to deal with the segmented data. These two approaches called: Holistic and Geometric define the main focus to extract the feature vector. These feature vectors can be used alone or can be combined in some way. Many questions can be stated: e.g. which approach is better for recognition?, Can fingers alone obtain better performance than the whole hand? and Is thermography hand information suitable for recognition due to its thermoregulation properties? A complete set of data ready to analyse, coming from the holistic and geometric approach have been designed and saved to test. Some innovative geometric approach related to curvature will be demonstrated. C) Finally the Biometric Dispersion Matcher (BDM) is used in order to explore how it works under different fusion schemes, as well as with different classification methods. It is the intention of this research to contrast what happen when using other methods close to BDM like Linear Discriminant Analysis (LDA). At this point, some interesting questions will be solved, e.g. by taking advantage of the finger segmentation (as five different modalities) to figure out if they can outperform what the whole hand data can teach us.
El Reconeixement Biomètric fa referència a la identi cació automàtica de persones fent us d'alguna característica o modalitat anatòmica (empremta digital) o d'alguna característica de comportament (signatura). És un aspecte fonamental en qualsevol procés relacionat amb la seguretat, la compartició de recursos o les transaccions electròniques entre d'altres. És converteix en un pas imprescindible abans de concedir l'autorització. Aquesta autorització, s'entén que protegeix recursos clau, permeten així, que aquests siguin utilitzats pels usuaris que han estat autoritzats a utilitzar-los o a tenir-hi accés. Els sistemes biomètrics poden funcionar en veri cació, on es resol la pregunta: Soc jo qui dic que soc? O en identi cació on es resol la qüestió: Qui soc jo? La comunitat cientí ca ha incrementat els seus esforços per millorar el rendiment dels sistemes biomètrics. En funció de l'aplicació, diverses solucions s'adrecen a treballar amb múltiples modalitats o combinant diferents mètodes de classi cació. Donat que incrementar el número de modalitats, representa a la vegada problemes pels usuaris, moltes d'aquestes aproximacions no arriben mai al mercat. La tesis contribueix principalment en tres grans àrees, totes elles amb el denominador comú següent: Reconeixement biometric a través de les mans. i) La primera d'elles constitueix la base de qualsevol estudi, les dades. Per poder interpretar, i establir un sistema de reconeixement biomètric prou robust amb un clar enfocament a múltiples fonts d'informació, però amb el mínim esforç per part de l'usuari es construeix aquesta Base de Dades de mans multi espectral. Les bases de dades biomètriques constitueixen un recurs molt preuat per a la recerca; sobretot si ofereixen algun element nou com es el cas. Imatges de mans en diferents espectres electromagnètics: en visible (VIS), en infraroig (NIR) i en tèrmic (TIR). Amb un total de 100 usuaris, i 10 mostres per usuari, constitueix un bon punt de partida per estudiar i posar a prova sistemes multi biomètrics enfocats a les mans. ii) El segon bloc s'adreça a les dues aproximacions existents en la literatura per a tractar les dades en brut. Aquestes dues aproximacions, anomenades Holística (tracta la imatge com un tot) i Geomètrica (utilitza càlculs geomètrics) de neixen el focus alhora d'extreure el vector de característiques. Abans de tractar alguna d'aquestes dues aproximacions, però, és necessària l'aplicació de diferents tècniques de preprocessat digital de la imatge per obtenir les regions d'interès desitjades. Diferents problemes presents a les imatges s'han hagut de solucionar de forma original per a cadascuna de les tipologies de les imatges presents: VIS, NIR i TIR. VIS: imatges sobre exposades, anells, mànigues, braçalets. NIR: Ungles pintades, distorsió en forma de soroll en les imatges TIR: Dits freds La segona àrea presenta aspectes innovadors, ja que a part de segmentar la imatge de la ma, es segmenten tots i cadascun dels dits (feature-based approach). Així aconseguim contrastar la seva capacitat de reconeixement envers la ma de forma completa. Addicionalment es presenta un conjunt de procediments geomètrics amb la idea de comparar-los amb els provinents de l'extracció holística. La tercera i última àrea contrasta el procediment de classi cació anomenat Biometric Dispersion Matcher (BDM) amb diferents situacions. La primera relacionada amb l'efectivitat respecte d'altres mètode de reconeixement, com ara l'Anàlisi Lineal Discriminant (LDA) o bé mètodes com KNN o la regressió logística. Les altres situacions que s'analitzen tenen a veure amb múltiples fonts d'informació, quan s'apliquen tècniques de normalització i/o estratègies de combinació (fusió) per millorar els resultats. Els resultats obtinguts no deixen lloc per a la confusió, i són certament prometedors en el sentit que posen a la llum la importància de combinar informació complementària per obtenir rendiments superiors.

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Clarke, Fiona Catherine. "Near-infrared microscopy and image analysis for pharmaceutical process control." Thesis, University College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432883.

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Karlsson, Jonas. "FPGA-Accelerated Dehazing by Visible and Near-infrared Image Fusion." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28322.

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Fog and haze can have a dramatic impact on vision systems for land and sea vehicles. The impact of such conditions on infrared images is not as severe as for standard images. By fusing images from two cameras, one ordinary and one near-infrared camera, a complete dehazing system with colour preservation can be achieved. Applying several different algorithms to an image set and evaluating the results, the most suitable image fusion algoritm has been identified. Using an FPGA, a programmable integrated circuit, a crucial part of the algorithm has been implemented. It is capable of producing processed images 30 times faster than a laptop computer. This implementation lays the foundation of a real-time dehazing system and provides a significant part of the full solution. The results show that such a system can be accomplished with an FPGA.

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Touse, Michael P. "Demonstration of a near and mid-infrared detector using multiple step quantum wells." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FTouse.pdf.

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Quartel, John Conrad. "A study of near-field optical imaging using an infrared microscope." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313413.

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Flowerdew, Roland John. "Atmospheric correction for the visible and near-infrared channels of ATSR-2." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283392.

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Sabin, Guilherme Post 1977. "Estratégias quimiométricas aplicadas ao estudo de imagens químicas : novas possibilidades para caracterização de produtos e processos farmacêuticos." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249323.

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Orientador: Ronei Jesus Poppi
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
Made available in DSpace on 2018-08-22T17:44:22Z (GMT). No. of bitstreams: 1 Sabin_GuilhermePost_D.pdf: 9789223 bytes, checksum: 0f451c3cf56a345b71358f196448c6d9 (MD5) Previous issue date: 2013
Resumo: A indústria farmacêutica está em constante busca por novas tecnologias analíticas capazes de fornecer informações relevantes sobre produtos e processos industriais. Esta tese sugere novas possibilidades no estudo de medicamentos através de imagens químicas obtidas por microespectroscopia na região do infravermelho próximo e as seguintes ferramentas quimiométricas: MLR, CLS, MCR e PLS. Os trabalhos estão divididos em quatro tópicos e contribuem para o avanço analítico neste campo de conhecimento. Na primeira aplicação, foi realizado um estudo da similaridade entre imagens obtidas por técnicas quimiométricas distintas. O trabalho mostra como estimar limites de confiabilidade para a concentração por pixel de imagem. Assim, foi possível diminuir o tempo de aquisição de imagens mantendo a confiabilidade analítica no estudo de comprimidos de carbamazepina. O segundo estudo mostra uma aplicação onde a vantagem de segunda ordem foi requerida. Este estudo traz uma abordagem nova sobre o reconhecimento de padrões de imagem na caracterização de produtos farmacêuticos. Na terceira aplicação, o objetivo foi acompanhar o desenvolvimento industrial de um produto farmacêutico com baixo teor de ativo, auxiliando no processo de decisão em termos de micro-homogeneidade da formulação. O estudo mostrou que a concentração local pode ser explorada como vantagem analítica. Na quarta aplicação, foi abordado pela primeira vez na literatura, o estudo da estrutura de pellets farmacêuticos através de informações químicas obtidas por espectroscopia de imagem química na região do infravermelho próximo. Este trabalho abre alternativas para o estudo de medicamentos de entrega controlada.
Abstract: The pharmaceutical industry is constantly searching for new analytical technologies capable of providing relevant information about products and industrial processes. This thesis suggests new possibilities in the study of drugs by using chemical images obtained by microspectroscopy in the near infrared region and the following chemometric tools: MLR, CLS, MCR e PLS. The work is divided into four topics and it contributes to the advancement in the field of analytical knowledge. In the first application, a study was performed about the similarity between images obtained by different chemometric techniques. The work demonstrates how to estimate concentration reliability limits per image pixel. Thus, it was possible to shorten the time of image acquisition while maintaining analytical reliability in the study of carbamazepine tablets. The second study presents an application where the advantage of the second order was required. This study presents a new approach to the recognition of image patterns in the characterization of pharmaceuticals. In the third application, the aim was to follow the industrial development of a pharmaceutical product with a low active content, assisting in the decision about the process in terms of micro-homogeneity of the formulation. The study showed that the local concentration can be exploited for analytical advantage. In the fourth application, addressed in a publication for the first time, is the study of the structure of pharmaceutical pellets through chemical information obtained by near infrared chemical imaging. This work opens up alternatives for the study of controlled delivery drugs.
Doutorado
Quimica Analitica
Doutor em Ciências

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Carson, Kathryn Jane. "Contributions towards image reconstruction for functional imaging using time-resolved near-infrared measurements." Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240034.

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Laborde, Antoine. "Detection of minor compounds in food powder using near infrared hyperspectral imaging." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASB017.

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L’imagerie hyperspectrale proche infrarouge (PIR) permet d’obtenir une carte spectrale d’un échantillon organique. La mesure d’un spectre pour chaque pixel de la caméra permet notamment la recherche de composés minoritaires dans les poudres agroalimentaires. Cependant, l’analyse spectrale PIR est limitée à une couche de profondeur donnée. De plus, la taille des particules associée à une résolution insuffisante des caméras PIR actuelles induisent un mélange des signaux spectraux dans les pixels de l’image. Ces deux problèmes sont une limitation pour l’analyse des composés minoritaires dans les poudres agroalimentaires.Nous proposons une méthode permettant de déterminer la profondeur de détection d’une cible composite placée dans un produit pulvérulent tel que la farine de blé. Basée sur une régression par projection sur les structures latentes, cette méthode permet d’appréhender l’atténuation du signal PIR lorsque la couche de poudre augmente, et ce malgré les problèmes inhérents à la détection en profondeur.De plus, deux stratégies de démélange de spectres sont proposées dans le but de détecter les pixels contenant des signatures de particules minoritaires. Le manque de valeur de référence utilisées en tant que données de validation des algorithmes ainsi que l’ambiguïté des spectres des composés pures à démélanger sont deux difficultés majeures. Une première stratégie consiste à modélisation la variabilité des spectres étudiés via l’Analyse en Composantes Principales afin de construire un algorithme de détection performant. La deuxième stratégie, basée sur la Multivariate Curve Resolution Alternating Least-Squares permet le démélange des signaux par pixels dans un cas plus complexe
Near-infrared (NIR) hyperspectral imaging provides a spectral map for organic samples. Minor compounds in food powder can be looked for by analyzing the pixel spectra. However, the NIR spectral analysis is limited to a given depth. Besides, particles smaller than the pixel size induce a mixed spectral signature in the pixels. These two issues are an obstacle to the analysis of minor compounds in food powders.We propose a method to determine the detection depth of a composite target under a layer of powder such as wheat flour. It is based on the Partial Least Squares regression and provides an understanding of how the NIR signal is attenuated when the layer of powder despite the penetration depth issues.Two spectral unmixing strategies are proposed to detect pixel with minor compound NIR signatures. The lack of reference values to validate the model and the ambiguity of the spectral signature to unmix are two major difficulties. The first method models the spectral variability using Principal Component Analysis to design a performant detection algorithm. Then, for a more complex situation, the Multivariate Curve Resolution Alternating Least-Squares algorithm is used to unmix each pixel

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Rameau, Julien, Katherine B. Follette, Laurent Pueyo, Christian Marois, Bruce Macintosh, Maxwell Millar-Blanchaer, Jason J. Wang, et al. "An Optical/Near-infrared Investigation of HD 100546 b with the Gemini Planet Imager and MagAO." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/624214.

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We present H band spectroscopic and H alpha photometric observations of HD 100546 obtained with the Gemini Planet Imager and the Magellan Visible AO camera. We detect H band emission at the location of the protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2 sigma level with a Keplerian clockwise orbit at 59 au in the disk plane. The H band spectrum of the emission is inconsistent with any type of low effective temperature object or accreting protoplanetary disk. It strongly suggests a scattered-light origin, as this is consistent with the spectrum of the star and the spectra extracted at other locations in the disk. A nondetection at the 5 sigma level of HD 100546 b in differential H alpha imaging places an upper limit, assuming the protoplanet lies in a gap free of extinction, on the accretion luminosity of 1.7 x 10(-4) L-circle dot and M(M) over dot < 6.3 x 10(-7) M-Jup(2) yr(-1) for 1 R-Jup. These limits are comparable to the accretion luminosity and accretion rate of T-Tauri stars or LkCa 15 b. Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. This non-detection is consistent with the non-detection in the K. band reported in an earlier study but does not exclude the possibility that HD 100546 b is deeply embedded.

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Teresi, Michael Bryan. "Multispectral Image Labeling for Unmanned Ground Vehicle Environments." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/53998.

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Described is the development of a multispectral image labeling system with emphasis on Unmanned Ground Vehicles(UGVs). UGVs operating in unstructured environments face significant problems detecting viable paths when LIDAR is the sole source for perception. Promising advances in computer vision and machine learning has shown that multispectral imagery can be effective at detecting materials in unstructured environments [1][2][3][4][5][6]. This thesis seeks to extend previous work[6][7] by performing pixel level classification with multispectral features and texture. First the images are spatially registered to create a multispectral image cube. Visual, near infrared, shortwave infrared, and visible/near infrared polarimetric data are considered. The aligned images are then used to extract features which are fed to machine learning algorithms. The class list includes common materials present in rural and urban scenes such as vehicles, standing water, various forms of vegetation, and concrete. Experiments are conducted to explore the data requirement for a desired performance and the selection of a hyper-parameter for the textural features. A complete system is demonstrated, progressing from the data collection and labeling to the analysis of the classifier performance.
Master of Science

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Wong, Gerald. "Snapshot hyperspectral imaging : near-infrared image replicating imaging spectrometer and achromatisation of Wollaston prisms." Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2615.

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Conventional hyperspectral imaging (HSI) techniques are time-sequential and rely on temporal scanning to capture hyperspectral images. This temporal constraint can limit the application of HSI to static scenes and platforms, where transient and dynamic events are not expected during data capture. The Near-Infrared Image Replicating Imaging Spectrometer (N-IRIS) sensor described in this thesis enables snapshot HSI in the short-wave infrared (SWIR), without the requirement for scanning and operates without rejection in polarised light. It operates in eight wavebands from 1.1μm to 1.7μm with a 2.0° diagonal field-of-view. N-IRIS produces spectral images directly, without the need for prior topographic or image reconstruction. Additional benefits include compactness, robustness, static operation, lower processing overheads, higher signal-to-noise ratio and higher optical throughput with respect to other HSI snapshot sensors generally. This thesis covers the IRIS design process from theoretical concepts to quantitative modelling, culminating in the N-IRIS prototype designed for SWIR imaging. This effort formed the logical step in advancing from peer efforts, which focussed upon the visible wavelengths. After acceptance testing to verify optical parameters, empirical laboratory trials were carried out. This testing focussed on discriminating between common materials within a controlled environment as proof-of-concept. Significance tests were used to provide an initial test of N-IRIS capability in distinguishing materials with respect to using a conventional SWIR broadband sensor. Motivated by the design and assembly of a cost-effective visible IRIS, an innovative solution was developed for the problem of chromatic variation in the splitting angle (CVSA) of Wollaston prisms. CVSA introduces spectral blurring of images. Analytical theory is presented and is illustrated with an example N-IRIS application where a sixfold reduction in dispersion is achieved for wavelengths in the region 400nm to 1.7μm, although the principle is applicable from ultraviolet to thermal-IR wavelengths. Experimental proof of concept is demonstrated and the spectral smearing of an achromatised N-IRIS is shown to be reduced by an order of magnitude. These achromatised prisms can provide benefits to areas beyond hyperspectral imaging, such as microscopy, laser pulse control and spectrometry.

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Erickson, Sarah J. "Clinical Translation of a Novel Hand-held Optical Imager for Breast Cancer Diagnosis." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/407.

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Optical imaging is an emerging technology towards non-invasive breast cancer diagnostics. In recent years, portable and patient comfortable hand-held optical imagers are developed towards two-dimensional (2D) tumor detections. However, these imagers are not capable of three-dimensional (3D) tomography because they cannot register the positional information of the hand-held probe onto the imaged tissue. A hand-held optical imager has been developed in our Optical Imaging Laboratory with 3D tomography capabilities, as demonstrated from tissue phantom studies. The overall goal of my dissertation is towards the translation of our imager to the clinical setting for 3D tomographic imaging in human breast tissues. A systematic experimental approach was designed and executed as follows: (i) fast 2D imaging, (ii) coregistered imaging, and (iii) 3D tomographic imaging studies. (i) Fast 2D imaging was initially demonstrated in tissue phantoms (1% Liposyn solution) and in vitro (minced chicken breast and 1% Liposyn). A 0.45 cm3 fluorescent target at 1:0 contrast ratio was detectable up to 2.5 cm deep. Fast 2D imaging experiments performed in vivo with healthy female subjects also detected a 0.45 cm3 fluorescent target superficially placed ~2.5 cm under the breast tissue. (ii) Coregistered imaging was automated and validated in phantoms with ~0.19 cm error in the probe’s positional information. Coregistration also improved the target depth detection to 3.5 cm, from multi-location imaging approach. Coregistered imaging was further validated in-vivo, although the error in probe’s positional information increased to ~0.9 cm (subject to soft tissue deformation and movement). (iii) Three-dimensional tomography studies were successfully demonstrated in vitro using 0.45 cm3 fluorescence targets. The feasibility of 3D tomography was demonstrated for the first time in breast tissues using the hand-held optical imager, wherein a 0.45 cm3 fluorescent target (superficially placed) was recovered along with artifacts. Diffuse optical imaging studies were performed in two breast cancer patients with invasive ductal carcinoma. The images showed greater absorption at the tumor cites (as observed from x-ray mammography, ultrasound, and/or MRI). In summary, my dissertation demonstrated the potential of a hand-held optical imager towards 2D breast tumor detection and 3D breast tomography, holding a promise for extensive clinical translational efforts.

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Martinić, Ivana. "Novel perspectives in near-infrared optical imaging with lanthanide based molecules, macromolecules and nanomaterials." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2033.

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Le domaine du proche infrarouge a une importance majeure pour l'imagerie optique en raison de la faible autofluorescence des systèmes biologiques et de la diffusion limitée de la lumière permettant l’amélioration du rapport signal-sur-bruit et une pénétration plus profonde dans les tissus. Les sondes fluorescentes proche-infrarouges les plus couramment utilisées à ce jour sont les fluorophores organiques ou les nanocristaux semi-conducteurs qui sont affectés par un certain nombre d’inconvénients. Plusieurs cations lanthanide possèdent des propriétés optiques uniques comme des bandes d'émissions étroites dont les longueurs d'ondes sont très peu sensibles à l’environnement, de grandes différences d’énergie entre longueurs d’onde d’excitation et d'émission et une forte résistance au photoblanchiment. Afin de bénéficier de la luminescence des lanthanides, les faibles absorbances des cations lanthanides libres doivent être compensées par l'utilisation de groupes chromophores appropriés fonctionnant comme sensibilisateurs. On parle d’effet d’"antenne". Nous présentons dans ce travail plusieurs familles de sondes à base de lanthanides (i) de petites molécules, plus spécifiquement des complexes monométalliques constitués par la coordination de Ln³⁺ par un ligand de type TTHA-anthraquinone et des métallacrowns polymétalliques Ln³⁺/Zn²⁺ auto-assemblés; (ii) de nouveaux nanomatériaux basés sur des billes de polystyrène possédant deux types de chargements différents, à savoir (i) un complexe bimétallique d-f Cr³⁺-Ln³⁺ ainsi que (ii) des antennes dérivées d’hydroxyanthraquinone et des cations lanthanide libres; (iii) des macromolécules de type dendrimère polyamidoamine de génération 3 fonctionnalisés avec sensibilisateurs aza-BODIPY en leurs périphéries et qui encapsulent des lanthanide luminescents. Les propriétés photophysiques, la cytotoxicité et l'incorporation cellulaire ont été décrites et discutées pour chacun des types de sondes. En outre, ces sondes ont été testées en imagerie in vitro visible et/ou proche-infrarouge par des expériences de microscopie confocale et d’épifluorescence. L’ensemble des sondes décrites dans ce travail, en raison de leurs propriétés avantageuses et nouvelles, constituent des avancées majeures pour le développement de nouvelles générations d'agents d'imagerie optique
The near-infrared (NIR) region has a significant importance for optical imaging due to the minimal autofluorescence and reduced light scattering thus allowing for improved signal-to-noise ratio and deeper penetration through tissues. Nowadays, the most commonly used NIR-emitting fluorescent probes rely mainly on organic fluorophores or quantum dots and exhibit drawbacks. Several lanthanide(III) ions (Ln³⁺) possess unique optical properties e.g. sharp emission bands the wavelengths of which have minimal sensitivity to the microenvironment, large differences between excitation and emission wavelengths and strong resistance toward photobleaching. In order to obtain the luminescence of lanthanides, the low absorbances of the free Ln³⁺ have to be overcome by the use of appropriate chromophoric groups functioning as a sensitizing “antenna”. We present here several families of Ln³⁺-based probes: (i) small molecules, in particular monometallic complexes constituted by the TTHA-anthraquinone moiety and Ln³⁺, and polymetallic self-assembled Ln³⁺/Zn²⁺ metallacrowns; (ii) novel nanomaterials based on polystyrene beads with two different loadings, i.e. d-f bimetallic Cr³⁺- Ln³⁺+ complex and hydroxyanthraquinone antennae and Ln³⁺ ; (iii) macromolecular generation-3 polyamidoamine dendrimers functionalized with aza-BODIPY sensitizers at their periphery and encapsulating the luminescent Ln³⁺. The photophysical properties, cytotoxicity and cellular uptake were reported and discussed for each of the presented types of Ln³⁺-based probes. Moreover, these probes were successfully tested for visible and/or NIR in vitro imaging by confocal or epifluorescence microscopy experiments. Finally, the reported Ln³⁺-based probes, due to the number of advantageous properties, represent significant breakthroughs toward the developments of new generations of optical imaging agents

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Khalaf, Reem. "Image reconstruction for optical tomography using photon density waves." Thesis, University of Hertfordshire, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302304.

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Bouccara, Sophie. "Time-gated detection of near-infrared emitting quantum dots for in vivo cell tracking in small animals." Paris 7, 2014. https://pastel.archives-ouvertes.fr/tel-01083824.

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Le suivi de cellules in vivo est essentiel afin de déterminer par exemple les voies de migration de cellules tumorales circulantes ou encore pour suivre l'activité de cellules immunitaires. La microscopie de fluorescence assure une bonne résolution ainsi qu'une grande sensibilité et semble adaptée à la détection de cellules uniques in vivo dans un modèle de souris. Néanmoins, sa sensibilité est limitée par deux principaux facteurs: le signal d'autofluorescence des tissus d'une part, et l'absorption et la diffusion de la lumière visible dans les tissus d'autre part. Nous présentons la synthèse et la caractérisation optique des quantum dots Zn-Cu¬In-Se/ZnS composés de matériaux peu toxiques. Ces nanoparticules possèdent un maximum d'émission centré autour de 800 nm, où l'absorption et la diffusion par les tissus biologiques sont limitées. Elles sont rendues biocompatibles grâce à une chimie de surface développée au laboratoire qui permet d'obtenir des sondes petites, brillantes et stables en milieu intracellulaire pendant plusieurs jours. Grâce à leur temps de vie fluorescence beaucoup plus long (150 ns) que celui de l' autofluorescence des tissus (< 5ns), nous avons développé un microscope de fluorescence résolu en temps qui permet de sélectionner le signal d'une cellule isolée marquée par des quantum dots et rejeter l'autofluorescence du tissu environnant. Nous présentons également les premières images in vivo de veines marquées avec ces sondes et observées avec notre microscope
In vivo cell tracking is a promising tool to improve our understanding of certain biological processes (circulating tumour cells migration, immune cells activity). Fluorescence microscopy ensures a high resolution and a good sensitivity. The latter is however limited by the high tissue autofluorescence and poor visible light penetration depth. We present the synthesis and characterization of Zn-Cu-In-Se / ZnS (core/shell) QDs made of low toxicity materials. These QDs exhibit a bright emission centred around 800 nm, where absorption and scattering of tissues are minimal. These nanocrystals are coated with a new surface chemistry, which yields small and bright probes in the cell cytoplasm for several days after labelling. These QDs also present a fluorescence lifetime much longer (150 ns) than the tissue autofluorescence (<5 ns). By combining a pulsed excitation source to a time-gated fluorescence imaging system, we show that we can efficiently discriminate the intracellular QDs signal from autofluorescence in an ex vivo sample and thus increase the detection sensitivity of labelled cells into tissues. We also report preliminary results obtained in an in vivo sample

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BRITO, Lívia Rodrigues e. "Determinação de aditivos detergentes dispersantes em gasolinautilizando a técnica do ring-oven e imagens hiperespectrais na região doinfravermelho próximo." Universidade Federal de Pernambuco, 2014. https://repositorio.ufpe.br/handle/123456789/17177.

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CNPq
A adição de aditivos detergentes dispersantes nas gasolinas brasileiras será obrigatória a partir de julho de 2015. É necessário, portanto, desenvolver uma metodologia que permita quantificar esses aditivos para verificar o cumprimento da lei. Neste trabalho, é proposto um método que associa a técnica do ring-oven com as imagens hiperespectrais no infravermelho próximo (NIR-HI). Como os aditivos são adicionados em baixas concentrações, a técnica do ring-oven foi empregada para concentrá-los previamente à análise por NIR-HI. Anéis foram produzidos a partir de amostras de gasolinas comum adicionadas dos aditivos (denominados G, T, W e Y) fornecidos pela Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) e as imagens adquiridas utilizando uma câmera hiperespectral (SisuCHEMA). Três estratégias de extração dos espectros do anel foram testadas a fim de se escolher a mais rápida e objetiva. A estratégia escolhida se baseia nos histogramas dos escores da primeira componente principal das imagens analisadas individualmente. Modelos de calibração individuais para cada aditivo foram construídos empregando a regressão por mínimos quadrados parciais (PLS), por isso, fez-se necessária uma etapa prévia de classificação. O melhor resultado para classificação foi obtido empregando a análise discriminante linear (LDA) associada ao algoritmo genético (GA) para seleção de variáveis, o qual apresentou uma taxa de classificações corretas de 92,31 %. Observou-se que a maioria dos erros de classificação envolveram amostras dos aditivos G e W. Um único modelo de regressão para esses dois aditivos foi, então, construído e seu erro foi equivalente aos dos modelos individuais. Os modelos de regressão apresentaram erros médios de predição entre 2 e 15 %. Esses resultados mostram que a metodologia proposta pode ser utilizada para determinar as concentrações dos aditivos com confiabilidade e garantir que eles estão sendo adicionados conforme a lei.
The addition of detergent dispersant additives to Brazilian gasoline will be mandatory from July 2015. It is necessary, therefore, to develop a methodology that allows quantifying these additives to verify their compliance with the law. In this work, a method that associates the ring-oven technique with near infrared hyperspectral images (NIR-HI) is proposed. Because the additives are added in low concentrations, the ring-oven technique was employed to concentrate them prior to the NIR-HI analysis. Rings were produced from samples of gasolines without additives spiked with additives (called G, T, W and Y) provided by the National Agency of Petroleum, Natural Gas and Biofuels (ANP) and the images were acquired using a hyperspectral camera (SisuCHEMA). Three strategies for extraction of the ring spectra were tested in order to select the faster and most objective. The chosen strategy is based on the histograms of the first principal component scores of the images analyzed individually. Regression models were built for each additive using partial least squares (PLS) regression, so it was necessary to have a previous classification stage. The best classification result was obtained using the linear discriminant analysis (LDA) associated with the genetic algorithm (GA) for variable selection, which showed a correct classification rate of 92.31 %. It was observed that most of the misclassification errors involved the samples of the G and W additives. A single regression model was then built for these two additives and its error was equivalent to the errors of the individual models. The regression models showed average prediction errors between 2 and 15 %. These results show that the proposed methodology can be used to determine the additive concentrations with reliability and to ensure that they are been added according to the law.

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Vidas, Dario. "Performance Evaluation of Stereo Reconstruction Algorithms on NIR Images." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191148.

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Stereo vision is one of the most active research areas in computer vision. While hundreds of stereo reconstruction algorithms have been developed, little work has been done on the evaluation of such algorithms and almost none on evaluation on Near-Infrared (NIR) images. Of almost a hundred examined, we selected a set of 15 stereo algorithms, mostly with real-time performance, which were then categorized and evaluated on several NIR image datasets, including single stereo pair and stream datasets. The accuracy and run time of each algorithm are measured and compared, giving an insight into which categories of algorithms perform best on NIR images and which algorithms may be candidates for real-time applications. Our comparison indicates that adaptive support-weight and belief propagation algorithms have the highest accuracy of all fast methods, but also longer run times (2-3 seconds). On the other hand, faster algorithms (that achieve 30 or more fps on a single thread) usually perform an order of magnitude worse when measuring the per-centage of incorrectly computed pixels.

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Williams, Paul James. "Near infrared (NIR) hyperspectral imaging for evaluation of whole maize kernels: chemometrics for exploration and classification." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1696.

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Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2009.
The use of near infrared (NIR) hyperspectral imaging and hyperspectral image analysis for distinguishing between whole maize kernels of varying degrees of hardness and fungal infected and non-infected kernels have been investigated. Near infrared hyperspectral images of whole maize kernels of varying degrees of hardness were acquired using a Spectral Dimensions MatrixNIR camera with a spectral range of 960-1662 nm as well as a sisuChema SWIR (short wave infrared) hyperspectral pushbroom imaging system with a spectral range of 1000-2498 nm. Exploratory principal component analysis (PCA) on absorbance images was used to remove background, bad pixels and shading. On the cleaned images, PCA could be used effectively to find histological classes including glassy (hard) and floury (soft) endosperm. PCA illustrated a distinct difference between floury and glassy endosperm along principal component (PC) three. Interpreting the PC loading line plots important absorbance peaks responsible for the variation were 1215, 1395 and 1450 nm, associated with starch and moisture for both MatrixNIR images (12 and 24 kernels). The loading line plots for the sisuChema (24 kernels) illustrated peaks of importance at the aforementioned wavelengths as well as 1695, 1900 and 1940 nm, also associated with starch and moisture. Partial least squares-discriminant analysis (PLS-DA) was applied as a means to predict whether the different endosperm types observed, were glassy or floury. For the MatrixNIR image (12 kernels), the PLS-DA model exhibited a classification rate of up to 99% for the discrimination of both floury and glassy endosperm. The PLS-DA model for the second MatrixNIR image (24 kernels) yielded a classification rate of 82% for the discrimination of glassy and 73% for floury endosperm. The sisuChema image (24 kernels) yielded a classification rate of 95% for the discrimination of floury and 92% for glassy endosperm. The fungal infected and sound whole maize kernels were imaged using the same instruments. Background, bad pixels and shading were removed by applying PCA on absorbance images. On the cleaned images, PCA could be used effectively to find the infected regions, pedicle as well as non-infected regions. A distinct difference between infected and sound kernels was illustrated along PC1. Interpreting the PC loading line plots showed important absorbance peaks responsible for the variation and predominantly associated with starch and moisture: 1215, 1450, 1480, 1690, 1940 and 2136 nm for both MatrixNIR images (15 and 21 kernels). The MatrixNIR image (15 kernels) exhibited a PLS-DA classification rate of up to 96.1% for the discrimination of infected kernels and the sisuChema had a classification rate of 99% for the same region of interest. The The iv sisuChema image (21-kernels) had a classification rate for infected kernels of 97.6% without pre-processing, 97.7% with multiplicative scatter correction (MSC) and 97.4% with standard normal variate (SNV). Near infrared hyperspectral imaging is a promising technique, capable of distinguishing between maize kernels of varying hardness and between fungal infected and sound kernels. While there are still limitations with hardware and software, these results provide the platform which would greatly assist with the determination of maize kernel hardness in breeding programmes without having to destroy the kernel. Further, NIR hyperspectral imaging could serve as an objective, rapid tool for identification of fungal infected kernels.

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Rémond, Maxime. "Développement de nouveaux chromophores dipolaires pour l'imagerie de fluorescence et l'imagerie photoacoustique." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN062.

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Cette thèse traite de la conception, la synthèse et la caractérisation de chromophores dipolaires D-π-A pour l’imagerie de fluorescence et l’imagerie photoacoustique.La première partie est consacrée à la synthèse et à l’étude de nouveaux fluorophores émettant à l’état solide dans le proche infrarouge, pour l’imagerie de fluorescence biphotonique. Afin d’améliorer les propriétés optiques à l’état solide, nous avons exploré différentes pistes en modifiant d’abord le groupement D donneur d’électron, puis le groupement A accepteur et enfin le pont π conjugué de nos structures dipolaires.La seconde partie concerne l’imagerie photoacoustique. Cette imagerie, basée sur une excitation optique et une détection acoustique, nécessite une forte absorption dans le proche infrarouge. Une des stratégies pour effectuer ce décalage bathochrome de l’absorption a été incorporation de groupements thiophènes à faible aromaticité, afin d’augmenter la délocalisation du système π. Parallèlement, nous avons aussi étudiés des hémicyanines, présentant de fortes absorptions au-delà de 650 nm.Enfin, les colorants ont été formulés en nanoparticules organiques afin d’acquérir une solubilité aqueuse pour leur application en imagerie. Deux types de nanoparticules ont été étudiés : la nanoprécipitation des colorants en présence d’un agent tensioactif, ainsi que l’encapsulation des colorants dans une matrice polymérique amphiphile stabilisée par une couche de silice. Les meilleurs chromophores ont permis l’acquisition d’images de cellules par microscopie biphotonique ainsi que d’images photoacoustiques de circuits microfluidiques et de la microvascularisation de souris in vivo
This thesis is focused on the conception, synthesis and characterization of dipolar dyes D-π-A for fluorescence imaging and photoacoustic imaging.The first part aim to synthesize and to study new fluorophores emitting in the solid-state in the near-infrared for fluorescence imaging with two-photon excitation. In order to improve the optical properties in the solid-state, we first explored various electron donating groups D, then acceptors A and finally we modified the π bridge. In a second part, we focused on dyes for photoacoustic imaging. This technique is based on an optical excitation and an acoustic detection. It requires a strong absorption in the biological window. To red shift the absorption we incorporated a thiophene bridge with low aromaticity to increase the delocalization. We also studied several hemicyanines with strong absorption above 650 nm.Finally, dyes were formulated as water-soluble nanoparticles for their final application for imaging. Two types of nanoparticles were studied: nanoprecipitated dyes stabilized by a surfactant to increase the colloidal stability or encapsulated dyes in a amphiphilic polymer matrix stabilized with a silica shell. Those nanoparticles enabled cells imaging with biphotonic florescence imaging as well as photoacoustic imaging of a microfluidic chip and of the microvascularisation of mice ears in vivo

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Edjlali, Ehsan. "Fluorescence diffuse optical tomographic iterative image reconstruction for small animal molecular imaging with continuous-wave near infrared light." Thèse, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10673.

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L’approximation par harmoniques sphériques (SPN) simplifiées de l’équation de transfert radiatif a été proposée comme un modèle fiable de propagation de la lumière dans les tissus biologiques. Cependant, peu de solutions analytiques ont été trouvées pour ce modèle. De telles solutions analytiques sont d’une grande valeur pour valider les solutions numériques des équations SPN, auxquelles il faut recourir dans le cas de tissus avec des géométries courbes complexes. Dans la première partie de cette thèse, des solutions analytiques pour deux géométries courbes sont présentées pour la première fois, à savoir pour la sphère et pour le cylindre. Pour les deux solutions, les conditions aux frontières générales tenant compte du saut d’indice de réfraction à l’interface du tissus et de son milieu environnant, telles qu’applicables à l’optique biomédicale, sont utilisées. Ces solutions sont validées à l’aide de simulations Monte Carlo basées sur un maillage de discrétisation du milieu. Ainsi, ces solutions permettent de valider rapidement un code numérique, par exemple utilisant les différences finies ou les éléments finis, sans nécessiter de longues simulations Monte Carlo. Dans la deuxième partie de cette thèse, la reconstruction itérative pour l’imagerie par tomographie optique diffuse par fluorescence est proposée sur la base d’une fonction objective et de son terme de régularisation de type Lq-Lp. Pour résoudre le problème inverse d’imagerie, la discrétisation du modèle de propagation de la lumière est effectuée en utilisant la méthode des différences finies. La reconstruction est effectuée sur un modèle de souris numérique en utilisant un maillage multi-échelle. Le problème inverse est résolu itérativement en utilisant une méthode d’optimisation. Pour cela, le gradient de la fonction de coût par rapport à la carte de concentration de l’agent fluorescent est nécessaire. Ce gradient est calculé à l’aide d’une méthode adjointe. Des mesures quantitatives utilisées en l’imagerie médicale sont utilisées pour évaluer la performance de l’approche de reconstruction dans différentes conditions. L’approche Lq-Lp montre des performances quantifiées élevées par rapport aux algorithmes traditionnels basés sur des fonction coût de type somme de carrés de différences.
Abstract : The simplified spherical harmonics (SPN) approximation to the radiative transfer equation has been proposed as a reliable model of light propagation in biological tissues. However, few analytical solutions have been found for this model. Such analytical solutions are of great value to validate numerical solutions of the SPN equations, which must be resorted to when dealing with media with complex curved geometries. In the first part of this thesis, analytical solutions for two curved geometries are presented for the first time, namely for the sphere and for the cylinder. For both solutions, the general refractiveindex mismatch boundary conditions, as applicable in biomedical optics, are resorted to. These solutions are validated using mesh-based Monte Carlo simulations. So validated, these solutions allow in turn to rapidly validate numerical code, based for example on finite differences or on finite elements, without requiring lengthy Monte Carlo simulations. provide reliable tool for validating numerical simulations. In the second part, iterative reconstruction for fluorescence diffuse optical tomography imaging is proposed based on an Lq-Lp framework for formulating an objective function and its regularization term. To solve the imaging inverse problem, the discretization of the light propagation model is performed using the finite difference method. The framework is used along with a multigrid mesh on a digital mouse model. The inverse problem is solved iteratively using an optimization method. For this, the gradient of the cost function with respect to the fluorescent agent’s concentration map is necessary. This is calculated using an adjoint method. Quantitative metrics resorted to in medical imaging are used to evaluate the performance of the framework under different conditions. The results obtained support this new approach based on an Lq-Lp formulation of cost functions in order to solve the inverse fluorescence problem with high quantified performance.

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Carneiro, Renato Lajarim. "Metodos quimiometricos aplicados a analise de medicamentos por espectroscopia de imagens." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249316.

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Orientador: Ronei Jesus Poppi
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Foram estudadas metodologias quimiométricas para análises exploratórias e quantitativas de preparações farmacêuticas utilizando a técnica de espectroscopia de imagens na região do infravermelho próximo (NIR) e início do infravermelho médio (MIR). Foram realizadas três aplicações como segue: 1ª Análise exploratória para diagnosticar separações de fases em um medicamento apresentado na forma de pomada. Foram utilizados os métodos de Análise das Componentes Principais (PCA) e Resolução Multivariada de Curvas ¿ Quadrados Mínimos Alternados (MCR-ALS). Foi possível constatar que o solvente do princípio ativo (API) não formava uma fase estável com o veículo utilizado, ocorrendo separação de fases; 2ª Análise exploratória para diagnosticar formação de cristais em um medicamento apresentado na forma de creme (emulsão). Foram utilizados os métodos PCA e MCR-ALS. Foi observada a cristalização do API com o solvente utilizado; 3ª Determinação da distribuição superficial do princípio ativo e excipientes em comprimidos, avaliando a homogeneidade da amostra. Foram utilizados modelos PCA para análise exploratória e modelos Quadrados Mínimos Parciais por Intervalos (iPLS) para quantificação. Os mapas de concentração mostraram que o medicamento em questão era homogêneo com exceção de alguns cristais presentes. De maneira geral, a técnica de espectroscopia de imagens mostrou grande potencial na determinação da homogeneidade de fármacos, gerando resultados que podem ser interpretados visualmente através dos mapas de absorção, escores ou de concentração.
Abstract: Chemometric methods were studied for exploratory and quantitative analysis of pharmaceutical preparations using near and mid infrared (NIR and MIR) imaging spectroscopy. Three applications were accomplished as follows: 1st Exploratory analysis to diagnose phase separation in a ointment formulation. It was used Principal Component Analysis (PCA) and Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) methods. Phase separation was observed between ointment base (vehicle) and solvent of the active ingredient (API); 2nd Exploratory analysis to diagnose crystallization process in a cream (emulsion). It was used PCA and MCR-ALS methods. Crystallization was observed after stability period due precipitation of a API salt; 3rd Determination of superficial distribution of the API and excipients in tablets in order to evaluate sample homogeneity. PCA models were used for exploratory analysis and Interval Partial Least Squares (iPLS) model was applied for API and excipient quantification. Concentration maps of tablets showed good API and excipient homogeneity, except for a few large crystals. These applications showed that imaging spectroscopy is a powerful tool for homogeneity studies of pharmaceutical preparations. Results of three applications could be visually interpreted through absorption, score and concentration maps.
Doutorado
Quimica Analitica
Doutor em Ciências

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Chen, Yu. "A Highly Efficient Biometrics Approach for Unconstrained Iris Segmentation and Recognition." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/310.

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This dissertation develops an innovative approach towards less-constrained iris biometrics. Two major contributions are made in this research endeavor: (1) Designed an award-winning segmentation algorithm in the less-constrained environment where image acquisition is made of subjects on the move and taken under visible lighting conditions, and (2) Developed a pioneering iris biometrics method coupling segmentation and recognition of the iris based on video of moving persons under different acquisitions scenarios. The first part of the dissertation introduces a robust and fast segmentation approach using still images contained in the UBIRIS (version 2) noisy iris database. The results show accuracy estimated at 98% when using 500 randomly selected images from the UBIRIS.v2 partial database, and estimated at 97% in a Noisy Iris Challenge Evaluation (NICE.I) in an international competition that involved 97 participants worldwide involving 35 countries, ranking this research group in sixth position. This accuracy is achieved with a processing speed nearing real time. The second part of this dissertation presents an innovative segmentation and recognition approach using video-based iris images. Following the segmentation stage which delineats the iris region through a novel segmentation strategy, some pioneering experiments on the recognition stage of the less-constrained video iris biometrics have been accomplished. In the video-based and less-constrained iris recognition, the test or subject iris videos/images and the enrolled iris images are acquired with different acquisition systems. In the matching step, the verification/identification result was accomplished by comparing the similarity distance of encoded signature from test images with each of the signature dataset from the enrolled iris images. With the improvements gained, the results proved to be highly accurate under the unconstrained environment which is more challenging. This has led to a false acceptance rate (FAR) of 0% and a false rejection rate (FRR) of 17.64% for 85 tested users with 305 test images from the video, which shows great promise and high practical implications for iris biometrics research and system design.

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Breitkreitz, Márcia Cristina 1979. "Desenvolvimento e caracterização de formulações de fármacos pouco solúveis em água empregando espectroscopia de imagem e quimiometria." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249322.

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Orientador: Ronei Jesus Poppi
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Este trabalho teve como objetivo demonstrar como a espectroscopia NIR e Raman de imagem, juntamente com diversos métodos quimiométricos podem auxiliar a tomada de decisões durante o desenvolvimento farmacêutico de formulações de fármacos pouco solúveis em água, tendo como modelo a atorvastatina cálcica. Foram avaliados dois excipientes inovadores, o Gelucire® 44/14 e o Soluplus® que serviram de base para o desenvolvimento das formulações. O Gelucire® 44/14 foi utilizado para o preparo de dispersões sólidas pelos métodos da fusão e da evaporação do solvente e formulações do tipo SEDDS (Self-Emulsifying drug Delivery Sytems), enquanto o Soluplus® foi utilizado para o preparo de dispersões sólidas pelo método da evaporação do solvente. Nas dispersões preparadas pelo método da fusão foram observados aglomerados do fármaco, enquanto o método de evaporação do solvente apresentou melhor homogeneidade na distribuição dos componentes, porém a amostra se apresentou enrijecida após a secagem. Com as formulacoes SEDDS foi possível contornar estes problemas. Foram obtidas dispersões sólidas homogêneas de atorvastatina em Soluplus® utilizando etanol como solvente e lactose como diluente. As imagens foram geradas por calibração univariada, análise de componentes principais (PCA), regressão em mínimos quadrados clássicos (CLS) e regressão em mínimos quadrados parciais (PLS) e os resultados foram comparados. O método CLS foi estudado com mais detalhes devido às suas vantagens para utilização na pesquisa farmacêutica. Os principais fatores que levaram à problemas de exatidão com este método foram identificados e procedimentos para contorná-los foram apresentados e discutidos.
Abstract: The aim of this work was to demonstrate how NIR and Raman image spectroscopy associated with different chemometric methods can support decision making during pharmaceutical development of formulations of low water soluble drugs, using atorvastatin calcium as a model drug. Two innovative excipientes were used, Gelucire® 44/14 and Soluplus®. The former was used to prepare solid dispersions by both hot melt and solvent evaporation methods and to formulate Self Emulsifying Drug Delivery Systems (SEDDS). The latter was used to prepare solid dispersions by the solvent evaporation method. In solid dispersions prepared by the hot melt method it was observed lumps of the drug, whereas the solvent evaporation method presented more homogeneous distribution of the components, even though the sample became stiffened after drying. By preparing SEDDS formulations, it was possible to overcome these problems. A homogeneous solid dispersion of atorvastatin in Soluplus® was achieved by using ethanol as solvent and lactose as diluent. Chemical images were generated by univariate calibration, principal component analysis (PCA), classical least squares (CLS) and partial least squares (PLS). The capability of these methods to generate chemical images were compared. CLS method was studied more carefully due to its advantages for pharmaceutical research use. The main features that lead to accuracy issues were identified both in Raman and in NIR spectroscopy and procedures to overcome them were presented and discussed.
Doutorado
Quimica Analitica
Doutora em Ciências

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30

Raes, Florian. "Imagerie photoacoustique couplée à l’échographie haute résolution et à la fluorescence infrarouge en oncologie préclinique translationnelle." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2082/document.

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L’imagerie préclinique est devenue une ressource incontournable pour l’évaluation de paramètres physiopathologiques, pour le suivi du développement tumoral ainsi que pour le développement de thérapies anticancéreuses. Les évolutions technologiques apparues ces dernières années ont conduit au développement de nouvelles modalités d’imagerie ayant un fort potentiel de translation vers la clinique. Ce manuscrit présente diverses approches par imagerie échographique, photoacoustique et de fluorescence dans le proche infrarouge pour le suivi de la pathologie cancéreuse. Dans un premier temps, nous nous sommes intéressés à la caractérisation de l’hypoxie et son suivi au cours du temps dans différents modèles de cancers humains. Différentes stratégies d’imagerie multimodale ont ensuite été mises en oeuvre pour évaluer l’efficacité d’une nouvelle prodrogue thérapeutique permettant la libération d’une molécule active dans le proche environnement tumoral sur des modèles humains de tumeurs pancréatiques, mammaires, pulmonaires. Enfin, dans un contexte de recherche translationnelle, nous avons exploré le potentiel de l’imagerie photoacoustique et de la fluorescence infrarouge pour la mise en évidence de l’invasion ganglionnaire tumorale en mettant en oeuvre des modèles de ganglions sentinelles minimalement envahis. Au cours de ce travail, nous avons montré l’intérêt du suivi de l’hypoxie tumorale en onco-pharmacologie et mis en évidence le fort potentiel de l’imagerie PA pour les approches translationnelles en oncologie. La principale limitation correspond à la profondeur relativement faible des régions explorables, mais ce point suscite actuellement de nombreux développements technologiques. Les études de faisabilité réalisées ainsi que la validation de protocoles de preuves de concept permettront l’exploitation en routine de ces nouvelles modalités d’imagerie
Preclinical imaging has become an unavoidable step for pathophysiological parameters assessments, for the follow up of tumor growth and for the anticancer therapies development. Technological improvements have emerged in recent years, allowing the emergence of new imaging modalities with a high potential for translation into clinical practice. This manuscript presents several approaches by ultrasound imaging, photoacoustics and near infrared fluorescence in order to monitor the cancer pathology. Initially, we focused on the characterization of hypoxia and its longitudinal assessment in various preclinical models of human cancers. Various multimodal imaging strategies were implemented to assess the efficacy of a new therapeutic prodrug allowing the release of an active molecule in the tumor microenvironment on human models of pancreatic, breast and lung tumors. Finally, in a context of translational research, we explored the potential of photoacoustic and near infrared fluorescence imaging to highlight the lymph node invasion by cancer cells implementing minimally invaded sentinel lymph node models. In this work, we have shown the interest in monitoring the tumor hypoxia in onco-pharmacology and highlighted the high potential of photoacoustic imaging for oncology translational approaches. The main limitation is the relatively shallow depth of regions that we can explore, but this point is currently subject to many technological developments. Feasibility studies performed and validation of proof of concept protocols will enable routine exploitation of these new imaging modalities

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Foucault-Collet, Alexandra. "Luminescent lanthanide metal-organic frameworks and dendrimer complexes for optical biological imaging." Thesis, Orléans, 2013. http://www.theses.fr/2013ORLE2027/document.

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Les composés à base de lanthanides luminescents possèdent des propriétés uniques offrant de nombreux avantages pour l’étude de problèmes biologiques et pour le diagnostic. Ils résistent notamment à la photodécomposition, possèdent des temps de vie de luminescence longs ainsi que des bandes d’émissions étroites qui ne se recouvrent pas. De plus, certains lanthanides émettent dans le proche infrarouge, ce qui les rend particulièrement intéressants pour des applications d'’imagerie in vivo. De part l’interdiction des transitions f → f, les cations lanthanides ont des coefficients d’extinction très faibles. C’est la raison pour laquelle, il est nécessaire d’utiliser un ou plusieurs sensibilisateur(s) (comme un chromophore organique) pour exciter le lanthanide par « effet antenne ». Nous proposons ici de nouveaux composés émettant dans le proche infrarouge dont la structure permet d’incorporer une densité importante de lanthanides et de sensibilisateurs par unite de volume : i) les nano-MOF Yb-PVDC-3 constitués de chromophores dérivés de dicarboxylates de phenylènevinylène qui sensibilisent les cations Yb3+ du réseau. ii) les complexes formés avec des ligands dendrimères dérivés de polyamidoamine de génération 3 capables de sensibiliser 8 lanthanides (Eu3+, Yb3+, Nd3+) par le biais de 32 antennes dérivées du groupe 1,8-naphthalimide. La caractérisation physique, photophysique et la biocompatibilité de ces composés ont été réalisées. Ils ont montré une bonne stabilité dans différents environnements. Leur faible cytotoxicité a permis d’obtenir des images de microscopie proche infrarouge sur cellules vivantes. La preuve de principe que les nano-MOFs et les dendrimères complexant des lanthanides peuvent être utilisés comme rapporteurs luminescents in cellulo et in vivo a été ici établie. Les résultats obtenus valident la stratégie d’utiliser ce type de matériel pour augmenter le nombre de photons émis par unité de volume afin d’obtenir une meilleure sensibilité de détection
Unique properties of luminescent lanthanides reporters explain their emergence for bioanalytical and optical imaging applications. Lanthanide ions possess long emission lifetimes, a good resistance to photodecomposition and sharp emission bands that do not overlap. In addition, several lanthanides emit in the near infrared (NIR) region of the electromagnetic spectrum making them very interesting for in vivo imaging. Free lanthanide cations have low extinction coefficients due to the forbidden nature of the f → f transition. Therefore, lanthanides must be sensitized using a photonic converter such as an organic chromophore through the “antenna effect". We report here new near-infrared emitting compounds whose structure allows to incorporate a high density of lanthanide cations and sensitizers per unit volume: i) nano-MOF Yb-PVDC-3 based on Yb3+ sensitized by phenylenevinylene dicarboxylates. ii) polymetallic dendrimer complexes formed with derivatives of new generation-3 polyamidoamine dendrimers. In these complexes, 8 lanthanide ions (Eu3+, Yb3+, Nd3+) can be sensitized by the 32 antenna derived from 1,8-naphthalimide. These two families of compounds were fully characterised for their physical, photophysical properties as well as for their biological respective compatibilities. They are stable in various media and their low cytotoxicity and emission of a sufficient number of photons are suitable for near-infrared live cell imaging. One of the main goal outcomes of this work is the establishment of the proof of principle that nano- MOFs and lanthanide derived dendrimers can be used for the sensitization of NIR emitting lanthanides to create a new generation of NIR optical imaging agents suitable for both in cellulo and in vivoapplications.The present work also validates the efficiency of the strategy to use both types of nanoscale systems described here to increase the number of emitted photons per unit volume for an improved detection sensitivity and to compensate for low quantum yields

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32

Bordy, Mathieu. "Synthèse et évaluation biologique de sondes fluorogènes pour la détection d’activités enzymatiques." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEN072.

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Cette thèse de doctorat traite de la conception et de l’évaluation de sondes fluorogènes pour la détection d’activités enzymatiques dans des contextes biologiques d’intérêt. L’élaboration de sondes fluorogéniques stables incorporant l’ELF-97 est une des thématiques de recherche activement poursuivie par notre équipe. Le développement avec succès de sondes peptidases et glycosidases a ouvert de nombreuses perspectives. Un premier chapitre sera dédié à la diversification de ces sondes, tout d’abord par la variation de substrats pour la détection de nouvelles glycosidases, puis par le développement d’un espaceur innovant dans un contexte particulier de sénescence cellulaire. Une sonde pour la détection de la β-galactosidase en milieu acide a notamment pu être synthétisée et testée. En parallèle, des travaux ont porté sur une nouvelle génération de sondes ciblant une famille d’enzymes à fort intérêt scientifique et sociétal : les β-lactamases. La synthèse et l’évaluation biologique préliminaire d’une première sonde modèle a démontré l’efficacité de cette nouvelle architecture moléculaire. Cette sonde a, par la suite, permis l’élaboration de premiers résultats d’imagerie dans le cadre d’une collaboration active avec une équipe de recherche japonaise. Enfin, un dernier volet sera consacré à un projet dont l’objectif n’est pas récent dans l’équipe : le développement d’alternatives à l’ELF-97 présentant une émission décalée vers le rouge ou le proche infrarouge. Ainsi, la synthèse de nouveaux fluorophores, leurs caractérisations physico-chimiques et des tests d’incorporation dans des dispositifs répondeurs ont notamment été réalisés. Plusieurs candidats se sont révélés à fort potentiel pour leur émission fortement décalée vers le rouge ou leur haute insolubilité. Ils pourraient permettre à terme l’adaptation de la technologie à une utilisation in vivo, but ultime de la technologie dans le cadre de l’imagerie moléculaire
This doctoral thesis deals with the design and evaluation of fluorogenic probes for the detection of enzymatic activities in biological contexts of interest.The development of stable fluorogenic probes incorporating ELF-97 is one of the research themes actively pursued by our team. The successful development of peptidases and glycosidases probes have opened many perspectives. A first chapter will be dedicated to the diversification of these probes, firstly by the variation of substrates for the detection of new glycosidases, then by the development of an innovative spacer in the context of cell senescence. In particular, a probe for the detection of β-galactosidase in acidic medium has been synthesized and tested.In parallel, work has focused on a new generation of probes targeting an enzyme family with strong scientific and societal interest : β-lactamases. The synthesis and the preliminary biological evaluation of a first model probe demonstrated the effectiveness of this new molecular architecture. This probe subsequently led to the development of first imaging results as part of an active collaboration with a Japanese research team.Finally, a last part will be devoted to a project whose objective is not recent in the team : the development of alternatives to the ELF-97 presenting a shifted emission towards the red or the near infrared. For this purpose, the synthesis of new fluorophores, their physicochemical characterizations and incorporation tests in responding devices have been carried out. Several candidates have proved to have high potential for two main reasons : strongly red-shifted emission or high insolubility. They could eventually allow the adaptation of the technology to an in vivo use, the ultimate goal of the technology in the context of molecular imaging

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33

Watson, Jeffrey R., Summer Garland, and Marek Romanowski. "Intraoperative visualization of plasmon resonant liposomes using augmented microscopy." SPIE-INT SOC OPTICAL ENGINEERING, 2017. http://hdl.handle.net/10150/625390.

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Plasmon resonance associated with nanoparticles of gold can enable photothermal ablation of tissues or controlled drug release with exquisite temporal and spatial control. These technologies may support many applications of precision medicine. However, clinical implementations of these technologies will require new methods of intraoperative imaging and guidance. Near-infrared laser surgery is a prime example that relies on improved image guidance. Here we set forth applications of augmented microscopy in guiding surgical procedures employing plasmon resonant gold-coated liposomes. Absorption of near-infrared laser light is the first step in activation of various diagnostic and therapeutic functions of these novel functional nanoparticles. Therefore, we demonstrate examples of near-infrared visualization of the laser beam and gold-coated liposomes. The augmented microscope proves to be a promisingimage guidance platform for a range of image-guided medical procedures.

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34

Silva, Carlos Juliano da 1985. "Comparação entre reflectância difusa convencional e imagem hiperespectral na região do infravermelho próximo para determinação de viscosidade Mooney e plasticidade Wallace em borracha natural." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249951.

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Orientador: Celio Pasquini
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: No presente trabalho foi feita uma comparação entre as técnicas de reflectância difusa convencional e imagem hiperespectral na região do infravermelho próximo para determinação de viscosidade Mooney (VM), plasticidade inicial (Po), plasticidade após envelhecimento acelerado (P30) e Índice de Retenção de Plasticidade (PRI) em amostras de borracha natural pré-vulcanizadas. Os espectros foram adquiridos utilizando dois espectrofotômetros com transformada de Fourier e uma câmera hiperespectral e os valores de referência determinados de acordo com suas respectivas normas ASTM. Foram construídos modelos de regressão PLS e os seus respectivos valores de erro médio quadrático da previsão (RMSEP) avaliados. Como resultados, foi possível observar um ganho na capacidade preditiva dos modelos PLS com o aumento da área medida de cada amostra. Os modelos obtidos por ambos os pré-processamentos (MSC e derivada de segunda ordem) não apresentaram diferenças significativas quanto às suas capacidades preditivas, ao passo que a seleção de variáveis usando o método Jack-Knife possibilitou a obtenção de modelos com menor número de fatores. Os valores de RMSEP dos modelos otimizados foram de 4,6; 2,9; 3,0 e 5,3 para a determinação da VM, Po, P30 e PRI. Embora os resultados para os três instrumentos possam ser considerados equivalentes, o uso da câmera hiperespectral apresenta algumas vantagens, tais como: tempo de aquisição espectral aproximadamente seis vezes menor quando comparada aos equipamentos convencionais e maior robustez para determinação da viscosidade e plasticidade na presença de contaminantes
Abstract: In this work a comparison between conventional diffuse reflectance (FT-NIR) and hyperspectral image (HI-NIR) in the Near-Infrared region for determination of Mooney viscosity (VM), initial Plasticity (Po), plasticity after accelerated aging and plasticity retention index (PRI) in pre-vulcanized rubber samples was made. The spectra were acquired by using two Conventional Fourier Transform Spectrometer and one hyperspectral camera. The reference values of the rheological parameters were determined according to their respective ASTM standards. Partial least squares (PLS) regression models were constructed and their respective root mean square error of prediction (RMSEP) were evaluated. As results, it was possible to observe a gain in the prediction ability of the PLS models with increasing probed area. The models obtained for both pretreatments (MSC and second derivative) showed no significant differences. However, the variables selection using the Jack-Knife method allowed to obtain models with a low number of factors. The RMSEP values of the optimized models were 4.6, 2.9, 3.0 and 5.3 for determination of MV, Po, P30 and PRI, respectively. Though the results for the three instruments can be considered equivalent, the hyperspectral image instrument presents some relevant advantages, being about six times faster than most of conventional bulk spectrometers, and producing robust spectral data by ensuring sample representativeness, and minimizing the degrading effect of the presence of contaminants
Mestrado
Quimica Analitica
Mestre em Química

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35

Pellerin, Morgane. "Elaboration de nanoparticules à luminescence persistante pour l'imagerie optique dans le domaine du visible et du proche infrarouge." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066537/document.

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Cette thèse porte sur l'élaboration de nanoparticules (NPs) à luminescence persistante pour l'imagerie optique dans le domaine du rouge profond et du proche infrarouge. Leur utilisation présente un avantage indéniable, l'étape d'irradiation pour obtenir l'état excité pouvant être réalisée avant injection, il est possible d'éviter tout stress des tissus et autres phénomènes d'autofluorescence. Dans les compositions chimiques étudiées, elles sont par ailleurs ré-excitables in vivo. Nous présentons une synthèse originale pour l'élaboration de " petites " NPs de ZnGa2O4 :Cr3+ par voie hydrothermale assistée par chauffage micro-onde qui peut être suivi d'un traitement thermique. Les caractérisations avancées des propriétés de luminescence persistante et la structure fine du matériau a montré une corrélation directe entre la luminescence et l'ordre local des cations dans la structure (répartition et distorsion des sites cationiques). Ainsi, nous avons montré l'effet bénéfique d'une calcination sans frittage sur l'amélioration des propriétés de luminescence. Nous avons également mis en évidence le gain apporté par l'ajout d'un codopant comme l'ion Bi3+ ou la modification de la matrice avec la substitution d'une partie des ions Ga3+ par des ions Ge4+. Les limites d'optimisation de ce matériau étant atteinte, une toute nouvelle voie a été ouverte dans cette thématique en dopant la matrice avec des ions Ni2+ pour déplacer la luminescence persistante dans le domaine du proche infrarouge. L'exploitation de cette nouvelle fenêtre pour l'imagerie optique devrait permettre d'imager plus profond dans les tissus avec un meilleur rapport signal/bruit
This thesis aims to develop persistent luminescent nanoparticles (NPs) for optical imaging in the deep red and near infrared range. Their use has a clear advantage as the irradiation step can be performed before injection, avoiding tissue stress and other autofluorescence phenomena. The chemical compositions studied are also re-excitable in vivo. We propose an original way of synthesis for the elaboration of “small” ZnGa2O4:Cr3+ NPs. Hydrothermal synthesis assisted by microwave heating followed by a heat treatment is used to obtain the NPs. The extensive characterization of the persistent luminescence properties and of the material’s fine structure showed a direct correlation between luminescence and local cation order in the structure (distribution and distortion of cationic sites). Thus, we have shown the benefits of a heat treatment without sintering on the improvement of luminescence properties. We have also highlighted the enhancement provided by the addition of a codopant such as Bi3+ ions or the modification of the matrix by substituting a part of Ga3+ ions by Ge4+ ions. The optimization limits of this material being reached, doping the matrix with Ni2+ ions to move the persistent luminescence in the near infrared range, opens a new pathway in this research field. Exploiting this new window for optical imaging should allow imaging deeper into tissue with a better signal-to-noise ratio

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Sitbon, Gary. "Synthèse et caractérisation de sondes bimodales à base de nanocristaux I-III-VI pour l'imagerie de fluorescence et l'IRM in vivo." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066596/document.

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La chirurgie guidée par l’imagerie de fluorescence est une technique prometteuse mais limitée par la faible profondeur de pénétration (inférieure au millimètre dans le visible) à cause de l’absorption et de la diffusion par les tissus. Elle est plus élevée dans la gamme du proche infrarouge (700-1000 nm) mais reste limitée à quelques centimètres. L’imagerie par résonance magnétique (IRM) permet d’obtenir des images sur corps entier mais ne peut être utilisée pour le suivi peropératoire. Le développement de sondes bimodales, fluorescentes et magnétiques, permet de coupler les avantages des deux techniques.Nous avons choisi de développer des sondes basées sur des nanocristaux fluorescents de CuIn(S,Se)2 car ils présentent une longueur d’onde d’émission modulable sur toute la gamme du proche infrarouge ainsi que des rendements quantiques, sections efficace d’absorption et photostabilités élevés. La croissance d’une coque épaisse de ZnS permet d’augmenter le rendement quantique qui peut atteindre 60 % dans les solvants organiques. L’incorporation d'ions Mn2+ dans la coque de nos objets permet de leur conférer un caractère paramagnétique. Les propriétés optiques et structurales ont été étudiées par spectroscopie (fluorescence et absorbance), RPE, DRX, MET/METHR et analyse élémentaire. Nos sondes sont transférées en milieu aqueux par un échange de ligands qui ne modifie pas leurs propriétés. Des mesures de relaxivités longitudinales ont permis de confirmer leur potentiel comme agent de contraste pour l’IRM pondérée en T1 et nous avons apporté une preuve de principe de l’utilisation de nos sondes in vivo en marquant des ganglions lymphatiques chez la souris
Fluorescence imaging is a promising technique for image-guided surgery. Because of diffusion and absorption of light by tissues, the low penetration depth (less than a millimeter) in the visible spectral range, which can reach a few centimeters in the near infrared (NIR) spectral range (700-1000 nm), limits its use. To overcome this limitation, fluorescence imgaging can be coupled with magnetic resonance imaging (MRI) which provides whole body images but cannot be used for intraoperative monitoring. Thus, the development of bimodal fluorescent and magnetic (for MRI) probes offers the opportunity to combine advantages from both imaging modalities.In this regard, we chose to use CuIn(S,Se)2 fluorescent semiconductor nanocrystals(or quantum dots) as a platform for the development of our probes. They display a size-tunable emission wavelength over the NIR spectral range and high quantum yield, absorption cross section and photostability. The growth of a thick shell of ZnS on these nanoparticles can increase the quantum yield up to 60 % in organic media.The incorporation of Mn2+ ions in the shell gives our probes a paramagnetic behavior. The influence of doping level on structural and optical properties is investigated using fluorescence and absorbance spectroscopy, EPR, XRD, TEM/HRTEM and elemental analysis. Our probes are solubilized in water through a ligand exchange and their properties remain stable in water. Longitudinal relaxivity measurements show that these probes can be used as MRI T1 contrast agents. As a proof-of-principle, we demonstrate that these probes can be used for the detection of lymph nodes in vivo

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Gonzalez, Jean. "Development and Testing of a Second Generation Hand-held Optical Imager." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/596.

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Hand-held optical imagers are developed towards clinical breast cancer imaging. Herein, a Gen-2 hand-held optical imager has been developed with unique features: (i) image curved breast tissues with ~86% surface contact, and (ii) perform reflectance and transillumination imaging using the novel forked probe heads. Extensive phantom studies were performed using 1% Liposyn solution (background, ~ 300 ml and 1000 ml volumes) and 0.45 cc India Ink (absorption) targets, under different target:background contrast ratios and target depths. Two-dimensional surface images detected target(s) up to 2.5 cm deep via reflectance imaging, and up to 5 cm deep via transillumination imaging. Preliminary studies on gel-based breast phantoms (~700 ml) detected targets via reflectance and transillumination imaging. Preliminary in-vivo reflectance studies on normal and cancerous breast tissues also detected targets, although with artifacts. In future, the portable Gen-2 imager has potential for clinical breast imaging via reflectance and transillumination approach after extensive in-vivo studies.

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Lescure, Robin. "Développement d’azaBODIPYs fonctionnalisables pour la conception de sondes d’imagerie bimodale et d’agents théranostiques." Thesis, Bourgogne Franche-Comté, 2020. https://nuxeo.u-bourgogne.fr/nuxeo/site/esupversions/21e2771a-9c75-46d7-9377-50e8f2536c32.

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L’utilisation in vivo de l’imagerie optique est encore aujourd’hui principalement limitée par le manque de sondes capables d’émettre dans le proche infrarouge, où les tissus biologiques sont plus transparents à la lumière. Les travaux présentés dans ce manuscrit abordent l’optimisation et la valorisation d’une plateforme fluorescente hydrosoluble dont les propriétés optiques peuvent permettre une utilisation in vivo. Deux applications distinctes ont été envisagées pour cette plateforme WazaBY (Water-soluble azaBODIPY) : une utilisation comme sonde bimodale TEP (ou TEMP) et optique, et une utilisation en tant qu’agent théranostique. Lors du premier projet issu de ces travaux de thèse, nous avons pu développer une sonde bimodale TEMP/optique radiométallée par l’indium-111 et vectorisée par un anticorps (trastuzumab). Sur modèles murins porteurs de tumeurs xénogreffées, il a été possible de réaliser une imagerie bimodale optique/TEMP, témoignant d’une très nette accumulation au sein de la tumeur dès 24 heures après injection. La sonde a également été validée pour la réalisation de chirurgie assistée par fluorescence. Dans le cadre du second projet de cette thèse, une première génération d’agents théranostiques, porteurs de complexes d’or pour la thérapie, ont été synthétisées. L’objectif de ce projet a été de développer une nouvelle entité thérapeutique traçable in vitro et in vivo par imagerie optique. Les résultats préliminaires in vitro ont indiqué une activité antiproliférative des théranostiques sur lignées cellulaires cancéreuses (4T1, MDA MB 231, CT26 et SW480) voisine de celle de l’auranofine. Dans une seconde partie, nous nous sommes focalisés sur le développement de sondes théranostiques dites « intelligentes », pour lesquelles une modification des propriétés photophysiques est attendu lors du relargage éventuel du centre métallique. Deux molécules ont ainsi pu être synthétisées, chacune présentant un comportement de type on/off
The in vivo use of optical imaging is still limited by the lack of near infrared emitting probes. This thesis work focuses on the optimization and valorization of a water-soluble fluorescent platform whose optical properties enable an in vivo use. Two distinct applications were investigated for this WazaBY (Water-soluble azaBODIPY) platform: use as a PET (or SPECT) / optical bimodal probe, and as a theranostic agent. Concerning the first project, we were able to develop a targetted SPECT/optical bimodal probe, which was radiometallated with indium 111. Using xenografted murine models, we were able to show a clear accumulation of the probe in the tumor 24 hours after injection. Moreover, the probe was validated as a contrast agent for fluorescence guided surgery experiment. The second project of this thesis began by the synthesis of a first generation of gold based theranostic agents. The goal was to develop a new therapeutic complex, which can be tracked in vitro and in vivo thanks to optical imaging. In vitro preliminary results showed that the theranostics displayed a cytotoxicity comparable to auranofin on the tested cell lines (4T1, MDA MB 231, CT26 and SW480). A second part of this project focused on the develoment of « smart » probes for a theranostic use. Those probes are designed to undergo photophysical properties changes, when their metallic centre, responsible for the therapeutic role, is released. Two molecules were synthesized, both displaying an on/off behavior

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Gofas, Salas Elena. "Manipulation of the illumination of an Adaptive Optics Flood Illumination Ophthalmoscope for functional imaging of the retina in-vivo High loop rate adaptive optics flood illumination ophthalmoscope with structured illumination capability In vivo near-infrared autofluorescence imaging of retinal pigment epithelial cells with 757 nm excitation." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS195.

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L’œil étant la seule fenêtre optique transparente de notre corps, il donne un accès unique à l’observation de réseaux neuronaux et vasculaires. Mais aujourd’hui une nouvelle ère s’ouvre pour l’imagerie haute résolution, qui ne doit plus se contenter de donner accès aux structures des tissus, mais aussi d’en apprécier les fonctions. En effet, on peut trouver dans l’imagerie rétinienne des biomarqueurs du fonctionnement de l’ensemble du corps humain. Des maladies neurodégénératives (Parkinson,Alzheimer) ou l’hypertension artérielle pourraient être ainsi précocement diagnostiquées par une imagerie de haute précision de la rétine. L’optique adaptative, adaptée à l’imagerie rétinienne dès 1997, a amélioré nettement la résolution spatiale des images rétiniennes entraînant la multiplication des études de rétine par ophtalmoscope. Elle a notamment été couplée avec l’ophtalmoscope à balayage, qui devint le choix le plus populaire par sa supériorité en résolution spatiale et sectionnement optique par rapport au plein champ. Cependant, contrairement aux systèmes à balayage, l’ophtalmoscope plein champ produit des images grand champ à forte cadence d’acquisition et sans distorsion. Dans mon travail de thèse, j’ai cherché à montrer qu’un tel système, associé à des modalités d’imagerie jouant sur la géométrie d’éclairement, pourrait apporter à la recherche sur la rétine. Pour atteindre cet objectif ambitieux, nous avons modiﬁé l’ophtalmoscope plein champ construit au Centre Hospitalier National des Quinze-Vingts avec un traitement d’image spéciﬁque et deux nouveaux instruments inspirés de la microscopie plein champ. Nous avons intégré ces instruments dans le trajet d’illumination de l’ophtalmoscope aﬁn de manipuler la géométrie de l’éclairage de la rétine. Ces nouvelles implémentations nous permettent de mettre en œuvre des techniques d’imagerie plus avancées, comme par exemple l’imagerie en champ sombre ou l’angiographie non invasive en proche infrarouge. Ces modalités d’imagerie ont été exploitées pour imager la rétine de façon fonctionnelle. Nous nous sommes intéressés principalement à la fonction de couplage de lumière des photorécepteurs et à la perfusion sanguine
As the only transparent optical window of our body, the eye gives a unique access to the observation of neural and vascular networks. Today however, a new era is opening up for high-resolution imaging, which should no longer be limited to giving access to tissue structures, but may also tackle their functions. In fact, biomarkers for the functioning of the whole human body can be found in retinal imaging. Neurodegenerative diseases (Parkinson's, Alzheimer's) or arterial hypertension could thus be diagnosed early by high precision imaging of the retina. In my thesis work, I intended to show how the full-field ophthalmoscope, associated to imaging modalities adjusting geometrical settings of the illumination, could contribute to research on the retina. To achieve this ambitious goal, we modified the full-field ophthalmoscope built at the National Hospital Center of Quinze-Vingts with a specific image processing and two new instruments inspired by full-field microscopy. We have integrated these instruments into the illumination path of the ophthalmoscope to manipulate the geometry of the retinal illumination. These new implementations allow us to make use of more advanced imaging techniques, such as dark field imaging or noninvasive near infrared angiography. These imaging modalities have been exploited to image the retina functionally. We focused mainly on the light coupling function of photoreceptors and on blood perfusion

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Clement, Benjamin. "Recherche de galaxies avec un grand décalage spectral vers le rouge (z=7.7) par imagerie en bande étroite." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10122/document.

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Briser la frontière observationnelle de l’Univers lointain suscite de nombreux axes de recherches dans la cosmologie moderne. Exigeantes par la sensibilité demandée, ces observations constituent aussi bien un défi technologique pour les prochaines générations d’instruments qu’une étape nécessaire à la compréhension des différentes étapes d’évolution de l’Univers. Une des étapes importantes est la réionisation du milieu intergalactique, époque charnière marquant la fin des “Âges Sombres”. Déterminer quand et comment ce processus s’est déroulé et quelles ont été les sources l’ayant déclenché et entretenu sont les principales questions motivant ces recherches. Les travaux présentés dans cette thèse participent à l’effort de la communauté scientifique internationale dans la caractérisation de l’histoire de l’époque de la réionisation en recherchant des galaxies à grand décalage spectral vers le rouge (redshift). Après un panorama complet des contraintes observationnelles actuelles sur l’époque de la réionisation, sont ensuite présentés les deux projets ayant fournis les données constituant la matière première de cette analyse. En utilisant une même technique d’imagerie en bande étroite dans le domaine de longueurs d’onde proche-infrarouge, des observations avec l’instrument WIRCAM (CFHT) et d’autres avec l’instrument HAWK-I (VLT) ont permis d’établir des contraintes robustes sur la fonction deluminosité des Emetteurs Lyman-α au redshift z = 7.7. A l’occasion de la présentation du second projet, la problématique de la stratégie observationnelle est abordée, notamment via l’utilisation des amas de galaxies comme lentilles gravitationnelles amplifiant le flux des sources d’arrière-plan. L’absence de confirmation spectroscopique des Emetteurs Lyman-– sélectionnés durant l’analyse des données WIRCAM et l’absence de candidats dans le sondage HAWK-I suggèrent une évolution de la fonction de luminosité des Emetteurs Lyman-– entre les redshifts z = 6.5, telle quedéterminée dans d’autres études, et z = 7.7. La tendance de cette évolution, en luminosité ou en densité de galaxies, ne peut pas encore être déterminée compte tenu de la variabilité des résultats obtenus à plus bas redshift. Si cette évolutions’effectuait en luminosité, ce pourrait être le signe d’une augmentation de l’opacité du milieu intergalactique au rayonnement Lyman-α causée par une plus importante fraction d’hydrogène neutre, ce qui est une signature attendue de la réionisation
Breaking through the observational frontier of the distant universe motivates numerous scientific cases in modern cosmology. Demanding by the required sensitivity, high-redshift observations provide both a technological challenge for next generation instruments and a necessary step toward the understanding of cosmic evolution. One critical epoch is the reionization of the intergalactic medium bringing to light the end of the so-called “Dark Ages”. Determine when and how this process took place and what were the sources that started and maintained the reionization are the mainquestions motivating this research. The work presented in this thesis contributes to the effort of the internationalscientific community in characterizing the reionization epoch history by searching for galaxies at high redshift. First, I describe the current observational constraints in a comprehensive chapter. Then the two datasets used in that work are presented. From narrow-band observations in the near-infrared with WIRCAM at the CFHT and HAWK-I at the VLT, I put strong constraints on the luminosity function of Lyman-α Emitters at z = 7.7. The best strategy for this type of survey is discussed, in particular with the use of massive galaxy clusters acting as gravitational lenses that amplify the flux from background sources. The lack of spectroscopic confirmation of candidates found with WIRCAM and the lack of candidates found with HAWK-I suggest an evolution of the luminosity function from z = 6.5. This evolution could be either in luminosity or in number density but somewhat discrepant results at lower redshift prevent any definitive answer to this question. If the evolution was mostly in luminosity, it could be interpreted as an increase in the opacity of the intergalactic medium caused by an increased fraction of neutral hydrogen, which is an expected signature of reionization

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Carter, John. "Étude des minéraux hydratés à la surface de Mars par les imageurs hyperspectraux OMEGA/MEx et CRISM/MRO." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00657804.

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La planète Mars a connu une période où l'eau liquide était durablement stable. Outre les vestiges morphologiques d'une activité hydrologique en surface, l'interaction chimique de l'eau avec la croûte basaltique s'est traduite par la formation d'argiles et de sels hydratés en surface et en profondeur. Ces minéraux hydratés ont été détectés à la surface de Mars en 2004 grâce à l'instrument OMEGA, l'imageur hyperspectral infrarouge proche embarqué sur la sonde européenne Mars Express. Leur étude permet de reconstruire l'histoire de l'activité aqueuse sur Mars et de caractériser une période ancienne où l'environnement a pu être favorable à l'apparition d'une chimie pré-biotique. Ce travail de thèse s'intéresse aux environnements aqueux de Mars en couplant les données minéralogiques des imageurs hyperspectraux embarqués OMEGA/Mars Express et CRISM/Mars Reconnaissance Orbiter avec la morphologie. De nouveaux outils de traitement et d'analyse des données sont développés et ont permis la détection et la caractérisation spectrale de plus d'un millier de dépôts de minéraux hydratés sur Mars, fournissant une vue d'ensemble de l'altération. Celle-ci a eu lieu principalement dans la première partie du Noachien et a surtout formé des phyllosilicates ferro-magnésiens de la famille des vermiculites et smectites. Une importante diversité minérale est par ailleurs constatée avec une dizaine de familles minérales différentes, traçants des conditions géo-chimiques variées. Placés dans leur contexte géologique, certaines détections permettent de proposer l'existence passée d'un système hydrologique sur l'ensemble de la planète qui a donné naissance à un cycle des argiles similaire au cycle terrestre. Il apparait par ailleurs que les cratères d'impact sont le contexte privilégié des minéraux hydratés, mais le lien entre ces derniers et les processus d'impact demeure ambigu. La découverte d'un cycle des argiles est compatible avec l'hypothèse d'une planète potentiellement habitable au Noachien mais qui devra être vérifiée par l'exploration in-situ.

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Nazarenko, Iuliia. "Lanthanide based dendrimers for photodynamic therapy and biological optical imaging." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2074.

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La thérapie photodynamique (PDT) est une méthode de lutte contre le cancer basée sur l’utilisation de la lumière et d’un composé sensible à la lumière, appelé photosensibilisateur (PS). Le PS absorbe la lumière et, en présence d’oxygène, engendre la production des dérivés réactifs de l'oxygène (DRO), lesquels sont toxiques et provoquent la régression de la tumeur. La limitation principale des PSs utilisés dans les tests cliniques est leur faible sélectivité envers les tissus cancéreux. Le but principal de ce projet est de créer des agents multifonctionnels combinant sur une même molécule l’activité PDT, la vectorisation et l’imagerie optique proche infrarouge. Dans cette région du spectre optique, les cellules possèdent une faible autofluorescence, et la lumière proche infrarouge pénètre plus profondément dans les tissus biologiques que la lumière visible. Nous proposons ici de modifier une structure dendrimérique de type poly(amidoamine) de génération 3, en tant que plateforme polyvalente. En effet, ce dernier possède trente-deux groupes terminaux qui peuvent être facilement substitués par des PSs. De plus, cette macromolécule peut complexer dans ses cavités jusqu’à 8 cations lanthanides émettant dans le proche infrarouge. Quatre nouveaux ligands dendrimère ont été synthétisés avec différents PSs tels que des dérivés de naphtalimide, d’anthraquinone et de tétraphénylporphyrine. De plus, le naphtalimide a été couplé avec des groupes dérivés de l’acide folique pour assurer la vectorisation envers les tissus cancéreux. Les complexes de lanthanide émettant dans le proche infrarouge ont été préparés pour chaque dendrimère. La caractérisation des performances des différents complexes a été réalisée. La production de DRO et la présence de complexes d’Yb(III) a été démontrée dans les cellules HL60. Les dendrimères modifiés par les groupes anthraquinone et tétraphénylporphyrine en tant que PS, ont montré, dans les cellules vivantes, une émission proche infrarouge lorsqu’ils sont sous la forme de complexe d’Yb(III). Les résultats obtenus montrent que les complexes de lanthanides formés avec des ligands dendrimères peuvent servir comme des agents de PDT et des rapporteurs luminescents proche infrarouge in cellulo
PDT is a cancer treatment that uses the combination of a nontoxic photoactivated molecule (photosensitizer), an appropriate source of light excitation and molecular oxygen to generate reactive oxygen species (ROS) leading to the decrease of size or to the destruction of tumors. However, the PDT efficiency of currently used drugs is limited by the selectivity for the cancer tissue. The main goal of this work is to develop a multifunctional agent which combines a PDT activity, a tumor targeting and near-infrared (NIR) optical imaging. The use of reporters that absorb at low energy is justified by low tissue autofluorescence and high tissue penetration depth in the NIR spectrum window. For this purpose, we have chosen the generation-3 poly(amidoamine) dendrimers as a versatile platform. Such macromolecules can incorporate eight NIR emitting lanthanide ions inside their branches forming species with thirty-two end groups at the periphery that can be substituted by suitable photosensitizers. Four new dendrimer ligands were synthesized with different photosensitizers, such as derivatives of naphthalimide, anthraquinone, and porphyrin. In addition the naphthalimide photosensitizer was functionalized with a targeting molecule, based on folic acid, to induce selectivity of the molecule towards cancer tissues. The corresponding NIR emitting lanthanide complexes were prepared for each dendrimer. Four Yb(III)-dendrimer complexes were characterized for their photophysical and ROS production properties. All complexes demonstrated a ROS production. The dendrimer functionalized with anthraquinone and tetraphenylporphyrin photosensitizers show strong NIR emission in living cells. These new multifunctional Yb(III)-dendrimer complexes have been designed to broaden the current scope of PDT agents and of NIR optical imaging agents

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Jouad, Kamal. "Développement de dendrimères PAMAMs à base de fluorophores organiques pour l’imagerie optique dans le proche infrarouge." Thesis, Orléans, 2020. http://www.theses.fr/2020ORLE3050.

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L’imagerie optique de fluorescence est l’une des nouvelles techniques peropératoires utilisées pour guider la chirurgie. En effet, cette technique permet au chirurgien de voir en temps réel pendant l'opération ce qu'il lui est impossible de discerner à l'œil nu. En outre, elle présente un fort potentiel car elle est non invasive et peu onéreuse. En principe, elle repose sur la détection de la fluorescence issue d’une molécule (appelée sonde) qui absorbe et émet dans le proche infrarouge (lambda >650 nm). Cependant, cette technique présente un certain nombre de limites qui se manifestent notamment par le manque de sondes proche infrarouge hydrosolubles. Le travail présenté dans cette thèse porte sur le développement de nouvelles molécules organiques fluorescentes dans le proche infrarouge à base de dendrimères de type polyamidoamine (PAMAM) de natures hydrophile et biocompatible. Une série de dendrimères PAMAMs, de plusieurs générations Gn (n= 0 à 3), à cœurs fluorescents a été efficacement synthétisée, caractérisée et leurs performances spectroscopiques ont été également établies in vitro et in vivo
Optical fluorescence imaging is one of the new intraoperative techniques used to guide the surgery. This technique allows the surgeon to see in real-time during the operation what it is impossible for him to discern with the naked eye. Furthermore, it has great potential because it is non-invasive and inexpensive. It is based on the detection of fluorescence from a molecule (called probe) which absorbs and emits in the near-infrared window NIR (lambda >650 nm). However, this technique has a certain number of limitations particularly the lack of water-soluble NIR probes. The work presented in this thesis concerns the development of new NIR fluorescent organic molecules based on polyamidoamine (PAMAM) dendrimers of hydrophilic and biocompatible nature. A series of PAMAMs dendrimers, of several Gn generations (n from 0 to 3), with fluorescent cores, has been efficiently synthesized, characterized, and were successfully used for in vitro and in vivo imaging

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Croset, Guillaume. "Caractérisation in situ par imagerie proche infrarouge en fabrication additive "fusion sur lit de poudre par faisceau d'électrons." Thesis, Université Grenoble Alpes, 2021. http://www.theses.fr/2021GRALI018.

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Le procédé de fabrication additive par fusion sur lit de poudre par faisceau d’électrons (E-PBF) permet la réalisation de pièces métalliques par fusion sélective de couches successives. Il peut cependant générer des défauts dans les pièces fabriquées. Afin d’améliorer la fiabilité de ce procédé, le besoin de contrôles in situ (pendant la fabrication) est devenu une exigence forte. L’objectif de ce travail est de mettre en place des stratégies de suivi in situ de la fabrication additive E-PBF. L’outil sélectionné est une caméra proche infrarouge (NIR) permettant d’obtenir des images des pièces en cours de fabrication. Un dispositif expérimental permettant de réaliser les acquisitions à l’aide d’une caméra proche infrarouge de façon automatisée a été mis en place en prenant en compte l’environnement contraignant (haute température, vide, dépôt de métal sur les parois). Deux stratégies de contrôle sont proposées. La première vise à prendre une image de chaque couche fabriquée, en l’occurrence à l’issue de l’étape de fusion. Des routines d’analyse d’images ont été développées et permettent d’identifier et de localiser les défauts (distorsions géométriques, porosités) à partir de leur signature thermique sur les images NIR. Une méthode de contrôle non destructif (tomographie aux rayons X) permet de valider la détection des défauts internes. La seconde stratégie de caractérisation consiste à réaliser l’acquisition d’images en continu afin d’analyser l’évolution temporelle des niveaux de gris, cette dernière apportant des informations reliées aux changements de température. Une méthodologie permettant de détecter, voire d’anticiper certains défauts liés à l’apport d’énergie délivrée par le faisceau d’électrons est proposée. Les deux stratégies de caractérisation doivent permettre de repérer les défauts au plus vite afin de mettre en place une action corrective dans la cadre d’un futur contrôle du procédé par une boucle fermée
Electron beam Powder Bed Fusion (E-PBF) is an additive manufacturing process that allows metallic parts to be built by selectively melting successive layers of powder. However, this process can generate defects in the fabricated parts. To improve the reliability of this process, there is a need to develop in-situ monitoring imaging techniques. The main objective of this work is to set up strategies to characterize in-situ the E-PBF process. The selected tool is a near-infrared (NIR) camera employed to obtain images of the parts being manufactured. The first part of the work has been dedicated to setting up an experimental device allowing to acquire near-infrared images in an automated way and by taking into account the constrained environment of E-PBF (high temperature, vacuum, metal deposit on the walls). Two strategies of in-situ monitoring of E-PBF are suggested. The first one aims at taking one image per layer, just after the melting stage. Image analysis routines were developed and allow to identify and determine the spatial distribution of the defects (geometrical distortions, porosity) from their thermal signatures on the NIR-images. The detection of internal defects is validated with a non-destructive characterization (X-rays computed tomography). The second strategy consists of carrying out continuous image acquisition to analyze the temporal evolution of the grey level which is directly related to temperature changes. A methodology allowing to detect, even to anticipate given defects related to the energy delivered by the electron beam has been proposed. Those two approaches should allow the defects to be identified as quickly as possible to apply a correction within the framework of future closed-loop process control

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Meyer, Yves. "Conception et développement de bras réactifs auto-immolables pour la synthèse de sondes pro-fluorescentes : applications à la détection de peptidases dans un contexte in-vivo." Thesis, Rouen, INSA, 2010. http://www.theses.fr/2010ISAM0018.

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L'objectif de cette thèse est la conception et le développement de bras espaceurs auto-immolables originaux situés entre le substrat peptidique et un fluorophore à phénol. Une première partie de ces travaux porte sur le développement de bras réactifs auto-immolables adaptés à la détection d'exopeptidases et à leur application pour la synthèse de sondes destinées à l'imagerie in-vivo de la caspase 3, une enzime impliquée dans le processus apoptotique. La seconde partie de ce travail relate les efforts effectués afin d'étendre l'utilisation des bras réactifs auto-immolables à la détection des endopeptidases, notamment les MMPs, une famille d'enzimes fortement impliquée dans la progression cancéreuse
The aim of this PhD work is the design and development of novel self-immolative species linking a peptide susbstrate to a phenolic fluorophore. A first part was dedicated to the development of self-immolative linkers for exopeptidases detection and their incorporation in caspase 3 probes to stain the apoptotic process. A second part was devoted to the extension of the strategy to endopeptidases, especially MMPs, an enzyme family mainly involved in cancer progression

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Larivière, Mélusine. "Nanoparticles functionalized with human antibodies for multimodal molecular imaging of atherosclerosis." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0389/document.

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L'athérosclérose, à l’origine de la plupart des maladies cardiovasculaires telles que l'infarctus du myocarde ou l'AVC, est la principale cause de décès dans le monde. Les cliniciens ont donc besoin de techniques d'imagerie fiables pour identifier les patients «vulnérables» porteur d’athérome à haut risque d'occlusion thrombotique. Cette pathologie est une maladie inflammatoire qui implique beaucoup d'acteurs cellulaires et moléculaires, parmi lesquels les cellules endothéliales et immunitaires, les lipoprotéines, les cellules apoptotiques et les plaquettes. L'imagerie moléculaire visant à détecter ces acteurs avant la survenue d'événements cardiovasculaires dramatiques est en plein essor. Des anticorps humains (HuAbs) sélectionnés par phage-display pour reconnaître des biomarqueurs de la pathologies ont ici proposés comme ligands servant à fonctionnaliser des vecteurs pour l'imagerie IRM, de fluorescence ou TEP. Les HuAbs ont été modifiés, en introduisant soit des Cystéines soit un site de reconnaissance pour la Sortase, afin de développer un greffage site-spécifique. Les agents ciblant ont été validés in vitro et ex vivo sur des coupes d'athérome de modèles animaux. Des résultats prometteurs ontété obtenus en injectant dans des souris ApoE-/- l’anticorps antiplaquettaire TEG4, apportant ainsi de nouvelles connaissances sur la biologie de l'athérome et la preuve de concept d'une possible détection des plaques à haut risque riches en plaquettes. Des améliorations sont en cours pour développer des agents de contraste multi-fonctionnalisés avec des HuAbs et permettant de réaliser une imagerie moléculaire multimodale de l'athérosclérose facilement transposable en clinique
Because cardiovascular diseases are the leading cause of death in the world, providing clinicians with reliable and straightforward imaging techniques to identify "vulnerable" patients from the general population appears like the Holy Grail of the cardiovascular field. Atherosclerosis, identified as the underlying condition for most acute cardiovascular events, is characterized by the constitution of a lipidrich atheroma plaque, driven both by excess cholesterol and inflammation, which eventual rupture triggers clotting into the blood flow. It involves a wealth of cellular and molecular actors, which are so many potential markers for molecular imaging, aiming at deciphering how to warn clinicians about the possible occurrence of myocardial infarction or stroke. Here, human antibodies (HuAbs) selected by phage-display for their recognition of over-expressed biomarkers of the pathology are proposed as targeting ligands. They were further engineered for site-specific grafting, either by introducing Cysteine or Sortase recognition tags, and used to target contrast agents for MRI, fluorescence, or PET imaging. In vitro and ex vivo validation studies were carried out on atheroma sections of animal models. In vivo studies in the ApoE-/- mouse model were realized with the anti-platelet TEG4 HuAb using MRI, which provided insights on the biological relevance and feasibility to detect platelets-rich, high-risk atheroma plaques. The development of contrast agents useful in multi-modality imaging, and multi-functionalized with HuAbs is underway. It should serve as an accurate molecular imaging method for atherosclerosis, further more easily translated into the clinical arena

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Gerbaud, Edouard. "Multi-modality imaging of atherosclerotic plaque using optical coherence tomography." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0132/document.

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Les technologies d'imagerie intravasculaire c’est à dire l’échographie endo-coronaire (IVUS)et la tomographie par cohérence optique (IV-OCT) sont des outils précieux pour aider audiagnostic de la plaque d’athérosclérose et guider les gestes thérapeutiques.Le chapitre 1 présente les inconvénients de la coronarographie dans la pratique clinique.Dans plusieurs circonstances, l’IVUS et l’OCT ont clairement une valeur supplémentaire quandils sont utilisés comme un outil diagnostique en cas d'ambiguïtés angiographiques. Nousavons récemment rapporté la première observation utilisant l’OCT pour décrire une dissectioncoronaire d'une branche septale perforante responsable d’un infarctus du myocarde.Le chapitre 2 porte sur la reproductibilité de I’OCT entre différents instituts concernant denombreux paramètres qualitatifs et quantitatifs de la plaque d'athérome. Le but de notre étudeétait d'étudier en plus de la reproductibilité inter- et intra-observateur, la variabilité inter-institutsde I’OCT concernant les mesures quantitatives et qualitatives et de la comparer à celle del’IVUS. Dans ce travail, nous avons observé que, dans la mesure de la surface de la lumièreendocoronaire, des diamètres minimum et maximum de cette même lumière endocoronaire,de la surface endo-luminale du stent, des diamètres minimum et maximum endo-luminaux dustent, par des analystes provenant de 2 laboratoires différents, la reproductibilité inter-institutsde I’OCT était nettement supérieure à celle de l’IVUS. Le Chapitre 3 présente 2 nouvelles technologies robustes d'imagerie intravasculaire hybridesdéveloppées dans le laboratoire du Professeur Guillermo J. Tearney: l’OCT couplée à laspectroscopie dans le proche infra-rouge (OFDI-NIRS) et l’OCT couplée à l’autofluorescencedans le proche infra-rouge (OFDI-NIRAF). Les premières procédures d’OFDI-NIRS chezl’homme sont prévues dans un avenir proche. Les premières procédures chez l’homme ontété réalisées chez 12 patients porteurs d’un angor stable entre Juillet 2014 et Janvier 2015.Les résultats de cette étude pilote ont montré que le signal d’autofluorescence recueilli(NIRAF) a été focalement trés élevé dans des endroits de la plaque d’athérome où la plupartdes phénotypes morphologiques en OCT d’une plaque à haut risque de rupture étaientévidents. Les substrats biochimiques de ce signal d’autofluorescence (NIRAF) sont encore àélucider
Intravascular imaging technologies i.e. IVUS and IV-OCT are valuable tools for interventionguidance and diagnostic plaque imaging.Chapter 1 introduces the drawbacks of coronary angiography in the clinical practice. In severalcircumstances, IVUS and IV-OCT have clearly an additional value when they are used as adiagnosis tool in case of angiographic ambiguities. We recently reported the first observationusing IV-OCT to describe a coronary dissection of a septal perforating branch causing AMI.Chapter 2 focuses on the inter-institute reliability of IV-OCT to determine qualitative andquantitative parameters of atherosclerotic plaque. The purpose of our study was to investigatefurther inter- and intra-observer reproducibility, the inter-institute variability for IV-OCT (OFDI)quantitative and qualitative measurements vs. IVUS measurements using publishedconsensus document definitions. In our work, we observed that in the measurement of lumenCSA, maximum and minimum lumen diameters, stent CSA, maximum and minimum stentdiameters by analysts from 2 different laboratories, inter-institute reproducibility of OFDI wasfound to be more consistent than IVUS.Chapter 3 present 2 new robust hybrid intravascular imaging technologies developed in Dr.Tearney’s laboratory i.e. OFDI-NIRS and OFDI-NIRAF, which may offer supplementary criteriafor plaque vulnerability. First-in-human OFDI-NIRS imaging procedures are anticipated in thenear future. First-in-human OFDI-NIRAF imaging procedures have been performed in a firstpioneering series of 12 stable patients between July 2014 and January 2015. Findings of thispilot study showed that NIRAF was focally elevated in plaque locations where most high-riskmorphologic phenotypes were evident. The biochemical substrates of the NIRAF signal stillhave to be elucidated

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Delmas, Anthony. "Contribution à l'étude de l'effet mirage : application aux mesures dimensionnelle et thermique par caméras visible proche infrarouge." Phd thesis, Toulouse, INPT, 2012. http://oatao.univ-toulouse.fr/8958/1/delmas.pdf.

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L’Institut Clément Ader Albi (ICAA) et l’Institut von Karman (IVK) mènent depuis un certain nombre d’années des travaux sur la radiométrie IR dans le but de faire de la thermographie quantitative (mesure de température vraie sans contact). Ces travaux ont permis d’explorer les potentialités de plusieurs bandes spectrales : 8-12µm, 3-5µm et plus récemment la bande 0,75-1,7µm (proche IR) à l’aide de caméras CCD (Si) ou VisGaAs. Les travaux effectués dans ce domaine spectral ont permis de mettre en évidence un certains nombre de perturbations renforcées par les hautes températures(T>800°C). Cette thèse aborde de façon détaillée le traitement d’un certain nombre de grandeurs d’influence liées à la mesure de différents paramètres dans le domaine du proche IR mais également étendus aux domaines du visible et de l’IR. La première de ces grandeurs est l’émissivité dont le traitement a déjà été abordé par d’autres études. La seconde grandeur d’influence touche plus particulièrement à la localisation des points chauds sur l’objet et la distorsion du champ de température apportée par les effets convectifs présents autour d’un objet à haute température, elle est le coeur de cette thèse. En effet, lorsqu’une pièce chaude se trouve dans un milieu ambiant beaucoup plus froid, il se crée un gradient de température et donc d’indice de réfraction autour de la pièce. Or les caméras travaillant dans les différentes bandes spectrales vont être plus ou moins sensibles à ces variations d’indices de réfraction du fait de la dépendance de l’indice optique avec la longueur d’onde et de la résolution spatiale de la caméra utilisée. Ce phénomène, appelé effet mirage, entraîne inévitablement une déformation des informations spatiales reçues par la caméra. Le but de cette thèse a donc été d’estimer et de proposer une première approche pour corriger l’erreur faite sur la mesure de température et/ou de déformation faites par caméras sur des pièces chaudes. La démarche générale du travail a donc été dans un premier temps de calculer le champ de température autour de l’objet considéré en se ramenant d’abord à des cas simplifiés. On en a déduit alors le champ de réfraction entraînant une « déformation » de l’objet, en faisant le lien entre T et n. Cette étape correspond à l’approche numérique de notre étude. Cette étape numérique a été réalisé à l’aide d’un outil de lancer de rayons développée à l’ICA. L’approche expérimentale a consisté à l’utilisation de méthodes telle que la BOS (Background Oriented Schlieren), la PIV, la srtioscopie afin de déduire le champ de déplacements provoqué par le panache convectif. Ces résultats ont été comparés à la méthode numérique et ceci pour différentes longueurs d’ondes. Enfin, une stratégie de correction d’images perturbées a été abordé à l’aide de méthodes telles que la transformée d’Abel inverse afin de remonter au champ d’indice de réfraction 2D axisymétrique à partir d’une déformation plane.

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Doulain, Pierre-Emmanuel. "Complexes de BODIPY - phosphine - or : application à la conception de théranostiques optiques." Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS036/document.

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Ce travail décrit de nouveaux composés thérapeutiques anticancéreux traçables par imagerie optique appelés théranostiques optiques.Après un premier chapitre bibliographique décrivant le contexte de l’imagerie et la thérapie des cancers, un deuxième chapitre présente une première série de théranostiques BODIPY-phosphine-or dont la synthèse a été optimisée (diminution du nombre d’étapes, baisse du temps de réaction, compatibilité avec une augmentation d’échelle). Leur conjugaison à des biomolécules (glucose, peptide) a été réalisée par une méthode simple et efficace par couplage entre l’atome d’or de la sonde et la fonction thiol de la biomolécule (modifiée ou non), conduisant à une liaison or-soufre. Elle permet une biovectorisation pour rendre les composés plus sélectifs des cellules tumorales vis à vis des cellules saines. Les études photophysiques et biologiques réalisées ont démontré tout le potentiel de ces théranostiques dans le cadre d’un suivi de composé in vitro et l’impact que pouvait avoir le vecteur choisi.Le troisième chapitre présente deux autres séries de théranostiques et précurseurs visant deux objectifs distincts pour rendre la sonde plus compatible avec une imagerie optique in vivo. La modification structurale de la plateforme BODIPY par introduction de groupements augmentant la conjugaison permet d’obtenir des BODIPYs absorbant et émettant dans la « fenêtre thérapeutique » (650 900 nm, proche infrarouge). Des études préliminaires in vivo ainsi que des tests en imagerie photoacoustique ont donné des résultats prometteurs. Une deuxième modification structurale par introduction de groupements encombrants sur chaque face du BODIPY vise à empêcher l’agrégation des BODIPYs en milieu biologique (phénomène connu pour affecter leurs propriétés optiques). Cette approche « Picket-Fence » des porphyrines transposée en série BODIPY a permis d’appliquer pour la première fois en série BODIPY le concept d’atropoisomérie et d’atropoisomères interconvertibles
This work describes new anticancer agents that could be detected by optical imaging, namely optical theranostics.After a first chapter describing the context of cancer imaging and therapy, a second chapter describes a first series of BODIPY-phosphine-gold theranostics, the synthesis of which has been optimized (less steps, shortening the reaction time, scale up). Their conjugation with biomolecules (glucose, peptide) has been achieved by developing a simple and efficient method that leads to the coupling between the gold atom of the probe and the thiol of the biomolecule (modified or not), leading to a gold sulfur bound. Hence, it makes the biovectorization of the probes possible in order to get selectivity against tumor cells compared with healthy cells. Subsequent photophysical and biological studies demonstrated the potential of such theranostics, such as in vitro monitoring, and the impact of a chosen biomolecule (vector).A third chapter presents two additional series of theranostics and precursors with two distinct objectives aimed at making the probe more suitable for in vivo optical imaging. A first structural modification of the BODIPY platform was achieved upon introducing chemical groups allowing an extention of the π conjugation. It leads to BODIPYs that absorb and emit in the « therapeutic window » (650 900 nm, NIR). Preliminary in vivo studies and preliminary photoacoustic imaging studies with such compounds led to promising results. A second structural modification upon introducing bulky groups on each face of the probe was aimed at preventing stacking of BODIPYs platforms in biological media (a phenomenon known to affect their optical properties). Hence, a porphyrin « Picket Fence » approach was successfully transposed to BODIPY together with the concept of atropisomery and atropisomer interconversion

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Yu, Tingting. "Solid state luminescent molecules, macromolecules and materials, their response to stimuli and their applications in devices." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN061.

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Au cours de cette thèse, nous avons développé de nouveaux chromophores conjugués luminescents présentant une alternance de groupements donneurs et accepteurs, avec une attention particulière quant à leurs propriétés d’émission dans le rouge et proche infra-rouge à l’état solide ou agrégats. Nous avons étudié l’influence de la longueur de chaine et de la nature de la substitution donneur/accepteur non seulement sur les propriétés optiques en solution mais aussi (et surtout) sur le matériau agrégé. Enfin, en utilisant les propriétés spécifiques de certains des composés développés selon cette approche, nous avons exploré leur potentiel pour des applications allant de matériaux fluorochrome stimuli-responsifs (sous forme de films) à l’élaboration de sondes à deux photons émettant dans le proche infra rouge pour l’imagerie biologique. Les principaux accomplissements de cette thèse sont les suivant: 1/ de nouveaux polymères alternant des motifs triarylamine (ou carbazole)/ tetraphenylethylene (TPE) dans leur chaine principale ont été synthétisés. Leurs propriétés d’émission à l’état solide présentent des caractéristiques d’agrégats-J, peu courant dans les dérivés TPE, ce que nous attribuons à l’arrangement linéaire des chaînes polymères; 2/ Une nouvelle famille de colorants diphenylamine/benzobisthiazole et leurs dérivés oligomères ont été synthétisés. Leurs propriétés de luminescence présentent une sensibilité marquée à la protonation, que nous avons utilisée dans la conceptions de dispositifs luminescents commutables par stimuli acide/base; 3/Nous avons exploré la possibilité d’introduire des modifications chimiques complémentaires sur cette nouvelle famille de chromophores, afin d’obtenir des composés luminescents à l’état solide dans le proche infrarouge, en particulier par un changement de la nature de la transition électronique à transfert de charge intramoléculaire vers une transition cyanine, par le biais d’une quaternarisation des fonction benzobisthiazole. D’autres modifications ont conduit à une amélioration de la biocompatibilté des molécules, de leurs propriétés AIE, ou encore de leur spécificité de marquage cellulaire; 4/ Ces nouveaux composés présentent une luminescence photo-commutable (de type allumé/éteint), qui pourrait présenter un intérêt dans l’élaboration d’agents de contraste pour l’imagerie de microscopie super-résolue
In this thesis, we developed new luminescent conjugated chromophores presenting an alternation of electron donor and acceptor groups, with a specific focus on their emission properties in aggregates or solid states in far-red or near infrared region. We studied the influence of chain length and donor/acceptor substitution not only on the optical properties of the isolated compounds, but also (and especially) on the material in its aggregated state. Finally, taking advantages of these specific properties of some of the as-designed candidates, we explored their potential applications ranging from fluorochromic stimuli-responsive sensors (in film form) to red and NIR luminescent two-photon probes for biological imaging. The main achievements of this thesis are the following: 1) new alternating triarylamine or carbazole / tetraphenylethylene (TPE) polymers were synthesized. Their solid state luminescence poseeses typical J-aggregates emission features in solid state, unusual in TPE derivatives that we relate to the linear polymeric nature of the object; 2) A new family of diphenylamine / benzobisthiazole chromophores and derived oligomers were synthesized . Their luminescence properties present a marked sensitivity to protonation, which we took advantage of in the making of acid-base responsive luminescent devices; 3) we explored the possibility of additional chemical transformations of the newly designed chromophore, in order to achieve solid state NIR emission, in particular by means of a change in the character of the electronic transition from Intra-Molecular Charge Tranfer (ICT) to Cyanine transition owing to benzothiazole quaternarization. Other modifications resulted in improvement of their AIE properties, bioavailability and selectivity of their cellular compartments staining ability; 4) These new compounds present a reversible photoinduced “on-off” switching of their luminescence properties, which might present an interest in the design of contrast-agents for super resolution imaging

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Dissertations / Theses on the topic 'Near infrared imagery'

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