Дисертації з теми "Coupled tags"

The upcoming Internet of Things is realizing the vision of a fully connected world: one of the key enablers for such technological revolution is the development of low-cost long-lasting sensors, able to become the physical interface to the real-world. In such a quest, the Radio Frequency Identication (RFID) is establishing itself as the most promising technology for passive sensing, thanks to its standardized communication protocol and its massive use in nowaday's logistics, which has driven down the costs of commercial components. The extensive research eort of the latest years on the topic has achieved remarkable results, but there are some open issues that still inhibit a full adoption of the technology, among which the current sacrice in communication capability experienced along with the sensing process. The present Work tries to tackle the current issues, by investigating the potentialities of using two or more coupled RFID tags and exploiting the mutual interaction between them to enable better solutions to the present questions. Both theoretical and experimental aspects will be considered: the mathematical formulation will show the eects of the interaction between tags, highlighting the potentialities in terms of concurrent sensing and communication, and also exhibiting new and visionary capabilities of communication from tag to tag. The design of a specic sensor (a crack enlargement sensor) as well as the analysis and synthesis of a generic wireless sensing platform based on RFID couplets will be presented, exhibiting the desired properties of stable communication during the sensing process. Moreover, suitable sensing parameters and advanced measurement techniques will be introduced, allowing for improved sensitivity and measurement-setup independence. Finally, the experimental part will provide a better insight into some possible applications of RFID grids, as sketched in the theory, and will demonstrate practical implementations of the proposed functionalities.

Différentes études empiriques montrent que l'effet du couplage mutuel et la position et l'orientation aléatoires des antennes tags dans un volume réduit entraînent une dégradation des indicateurs de performance d'un système RFID, tels que la distance et le taux de lecture. Cette thèse participe à l'analyse des performances d'un tel système RFID en explorant les phénomènes physiques à l'origine de la dégradation et en introduisant des techniques statistiques dans les investigations. Avant de procéder à l'étude du comportement de groupe, la sensibilité et l'impédance de deux puces RFID (Higgs-3 et Higgs-9) ont été mesurées. Deux tag RFID ont été utilisées, un tag commercial (ALN-9662) associé à la puce Higgs-3 et tag artisanal fabriqué au laboratoire pour s’adapter à la puce Higgs-9. La distance de lecture des deux tags a été mesurée ainsi que l'impédance de leur antenne. Les résultats des mesures ont été confrontés à des simulations électromagnétiques. Afin d'étudier différents cas de figure faisant intervenir des tags positionnés de manière aléatoire, un modèle électromagnétique et des outils de simulation (HFSS et NEC) ont été utilisés et les conclusions sont basées sur leurs résultats, tout en les validant dans quelques cas par des mesures. Pour simplifier davantage, les tags RFID sont modélisés par un ensemble de dipôles demi-onde, avec et sans le circuit d’adaptation sous forme de T-match, et le lecteur est remplacé par une onde plane. L'objectif est de confronter le comportement d'un tag isolé à celui du même tag entouré par d'autres tags et de conclure sur l'impact du type d'antenne, de la densité des tags, de l’impédance de charge et de la polarisation de l'onde sur l’observable de sortie. La liaison RFID est étudiée à travers son lien forward et reverse, et en utilisant un modèle multiport conventionnel pour les tags intégrant le couplage. Une analyse approfondie du bilan de puissance est effectuée et la puissance absorbée au niveau des charges (puces) et la puissance re-rayonnée au niveau des antennes sont évaluées. En ce qui concerne la liaison forward, le rapport entre la puissance absorbée par la puce d'un tag environné et celle d'un tag isolé est appelé puissance absorbée normalisée et constitue un outil utile pour estimer le pourcentage de tags inactifs dans un ensemble de tags. En ce qui concerne la liaison reverse, la surface équivalente radar (SER) des antennes chargées par une charge adaptée et par un court-circuit a été étudiée. La SER différentielle du tag isolé et celle du tag environné a également été évaluée et l'impact du couplage sur la puissance re-rayonnée a été étudié. Étant donné que dans un contexte aléatoire à haute densité, il est impossible de prédire les performances du système de manière réaliste avec une approche purement déterministe, plusieurs configurations de tags et de dipôles positionnés et orientés de manière aléatoire ont été simulées et les conclusions sont tirées à l'aide d'une analyse statistique. En d'autres termes, à la fin de cette étude, la dégradation des performances d'un tag particulier dans une configuration donnée de tags environnants doit être évaluée individuellement, mais les moments statistiques ainsi que les fonctions de répartition permettent de prédire le comportement d'une population de tags sous certaines conditions. Cette thèse aide le concepteur RFID à évaluer la performance d'un scénario RFID et éventuellement à ajuster certains paramètres d'entrée tels que la densité des tags afin d'atteindre les objectifs visés
Different empirical studies show that the effect of mutual coupling and the random position and orientation of tag antennas in a reduced volume result in a degradation of key performance indicators of an RFID system such as the read-range and the read-rate. This thesis takes part in the performance analysis of such an RFID system by exploring the physical phenomena behind the degradation and by introducing statistical techniques into investigations. Prior to the group behaviour investigations, the sensitivity and the impedance of two RFID chips (Higgs-3 and Higgs-9) have been measured. Two RFID tags have been used, a commercial one (ALN-9662) associated with the Higgs-3 chip and a home-made tag, which has been fabricated in laboratory to match the Higgs-9 chip. The read range of both tags has measured along with their antenna impedance. The measurement results have been confronted to electromagnetic simulations. In order to study various cases involving randomly positioned tags, an electromagnetic model and simulation tools (HFSS and NEC) have been used and the conclusions are based on their results while cross-validated in a few cases by measurements. To simplify any further, the RFID tags are modelled by a set of half-wave dipoles, with and without T-match, and the reader is replaced by a plane wave. The objective is to confront the behaviour of a single isolated tag to that of the same tag while surrounded by other tags and to conclude on the impact of the antenna type, the density of tags, the terminating load and the wave polarisation on the output under observation. The RFID link is studied through its forward and reverse links and by using a conventional grid model for tags including coupling. A thorough power budget analysis is conducted and the absorbed power at the level of the loads (chips) and the reradiated power at the level of the antennas are assessed. Regarding the forward link, the ratio of the absorbed power by the chip of a surrounded tag to that of an isolated tag is called normalised absorbed power and constitutes a useful tool to estimate the percentage of inactivated tags in the set. Regarding the reverse link, the Radar Cross Section (RCS) of loaded antennas with short-circuit and matched loads have been studied. The differential RCS of the isolated tag and that of the surrounded one has also been evaluated and the impact of coupling on the backscattered power have been studied. As in a high-density random context, predicting the system performances in a realistic way with a deterministic approach is impossible, several configurations of randomly positioned and oriented tags and dipoles have been simulated and the conclusions are drawn using statistical analysis. In other words, at the end of this study, the performance degradation of a particular tag in a given configuration of surrounding tags needs to be evaluated individually but the statistical moments as well as cumulative distribution functions allow to predict the behaviour of a population tags under given conditions. This thesis helps the RFID designer to assess the performance of an RFID scenario and eventually adjust some input parameters such as the density of tags in order to attain the desired objectives

Questions have been raised about the genomic complexity of the human genome, since it was reported that it only consisted of 32,000 genes. Alternative splicing is considered the explanation of the enormous difference between the number of genes and the number of proteins. Aligning expressed sequence tags (ESTs) to the genomic sequence has become a popular approach for gene prediction, revealing alternative splice variants. The aim in this thesis is to identify and analyse splice variants of the adhesion family of G protein-coupled receptors using EST data. 75% of the genes in the data set of 33 sequences were found to have a total of 51 splice variants. About half of the variants were considered functional.

The performance of commercial Radio Frequency Identification (RFID) tags is primarily limited by present techniques used for tag antenna design. Currently, industry techniques rely on identifying the RFID tag application (books, clothing, etc.) and then building antenna prototypes of different configurations in order to satisfy minimum read range requirements. However, these techniques inherently lack an electromagnetic basis and are unable to provide a low cost solution to the tag antenna design process. RFID tag performance characteristics (read-range, chip-antenna impedance matching, surrounding environment) can be very complex, and a thorough understanding of the RFID tag antenna design may be gained through an electromagnetic approach in order to reduce the tag antenna size and the overall cost of the RFID system. The research presented in this thesis addresses RFID tag antenna design process for passive RFID tags. With the growing number of applications (inventory, supply-chain, pharmaceuticals, etc), the proposed RFID antenna design process demonstrates procedures to design tag antennas for such applications. Electrical/geometrical properties of the antennas designed were investigated with the help of computer electromagnetic simulations in order to achieve optimal tag performance criteria such as read range, chip-impedance matching, antenna efficiency, etc. Experimental results were performed on the proposed antenna designs to compliment computer simulations and analytical modelling.

Les récepteurs couplés aux protéines G (RCPG) constituent la plus grande famille de récepteurs transmembranaires. Ils sont impliqués dans une large variété de processus physiologiques et par conséquent ils représentent une cible thérapeutique d'intérêt pour le développement de médicaments. Plusieurs études ont démontré que les RCPGs sont capables d'interagir entre eux pour former des complexes oligomériques. Cependant, leur existence in vivo et leur rôle fonctionnel reste sujet à débats. Afin de mieux appréhender ce phénomène, nous avons utilisé un RCPG de classe C comme modèle d'étude, le récepteur de l'acide γ-aminobutyrique (GABAB), qui est impliqué dans une grande variété de désordres neurologiques et psychiatriques. Son originalité réside dans le fait qu'il est un hétérodimère obligatoire composé de deux sous-unités : GABAB1 et GABAB2 (GB1 et GB2). La liaison de l'agoniste sur GB1 conduit à l'activation de GB2. Au cours de ma thèse, nous avons montré en utilisant une nouvelle approche biophysique basée sur un marquage fluorescent enzymatique appelé Snap-tag que, contrairement aux récepteurs métabotropiques du glutamate, le récepteur GABAB forme des dimères de dimères (tétramères). Cette organisation hétéro-oligomérique est assurée par des contacts stables entre les domaines extracellulaires des sous-unités GB1. De plus, nous avons apporté des données en faveur de l'existence physiologique de cet assemblage en utilisant des membranes de cerveau de rat et de souris. Dans une seconde partie, nous avons souhaité déterminer les conséquences fonctionnelles de cette organisation. Nos résultats suggèrent une efficacité de couplage à la protéine G réduite du récepteur GABAB lorsqu'il est associé en dimères de dimères. Collectivement, nos données rapportent pour la première fois, l'existence de larges complexes allostériques de RCPGs dans le cerveau
The G-protein coupled receptors (GPCR) constitute the main family of transmembrane receptors. They are involved in many physiological processes and, as a consequence, they represent a therapeutic target of interest for the development of new drugs. Few studies have demonstrated that GPCRs are able to interact with each other to form oligomeric complexes. However, the existence in vivo and the functional interest of these oligomers remain a subject of intense debates. To address this issue, we have used a class C GPCR as a model, the γ-aminobutyrate B receptor (GABAB), which is involved in a wide variety of neurological and psychiatric disorders. This receptor has the particularity to be an obligatory heterodimer composed of two subunits GABAB1 and GABAB2 (GB1 and GB2). Agonist binding on GB1 leads to G-protein activation by GB2. During my thesis, we developed a new biophysical approach based on an enzyme-mediated fluorescent labeling calle d Snap-Tag and showed that, unlike metabotropic glutamate receptors, GABAB forms dimers of dimers (tetramers). This oligo-heterodimers organization is mediated via stable contacts between extracellular domains of GB1 subunits. Furthermore, we brought evidence of the physiological reality of this assembly using rat and mouse brain membranes. Then, we aimed at assessing what would be the functional rational of the GABAB dimer of heterodimers. Our results suggest that the GABAB receptor has a lower G protein-coupling efficacy when associated into dimers of dimers. Altogether, our data report for the first time, the existence of large allosteric GPCR complexes in the brain

Radio frequency identification (RFID) is a well-known and fast-growing technology used to identify people, animals and products. RFID tags are used to replace bar codes in a wide range of applications, to mention just a few, retail, transportation, logistics and healthcare. The two main driving aspects for most of research and development projects concerning RFID tags are the reduction of assembly costs and the downsizing of microchips. In that respect and considering an Industry 4.0 scenario, the study of a new assembly approach for passive and high frequency RFID tags has been proposed and studied in this thesis. In this new approach, which is based on the inkjet printing technology, a specifically designed radio frequency integrated circuit (RFIC) will be delivered, inside a liquid dielectric droplet, onto the antenna and no longer placed and oriented precisely as it happens nowadays with pick-and-place and flip chip machines. After a landing phase, the liquid droplet (with the encapsulated chip) will self-aligns with respect to the contact thanks to capillary forces driven by specifically designed wetting conditions on the substrate of the antenna. Finally, with few additional steps, the complete RFID tag is created. This research project brings to light a considerable simplification and a very high potential of parallelization, compatible with large volume manufacturing methods, in comparison to nowadays existing technologies. This may substantially drive down the fabrication costs. An in-depth analysis of electrical performances have been carefully undertaken and compliance with the ISO/IEC 144443 standard has been verified. Mathematical models have been developed showing fundamental limits for the maximum tag reading range and power requirements of the RFID reader.

Mestrado em Ciências do Mar e das Zonas Costeiras
Given the close proximity between the Tagus and Sado estuaries, it is understandable that these two hydrodynamic systems have their discharges on the same coastal region. Several studies focus on the investigation of the complex circulation at the mouth of Tagus or Sado estuaries, however, the interaction between these two systems is not taken into account and there are no studies which contemplate the interaction between the two estuaries. With this objective, the three-dimensional model Delft3D-Flow was implemented in order to investigate the complex flows in Tagus and Sado estuaries and adjacent shelf. The numerical model was calibrated and validated using sea surface height, currents, salinity and water temperature data, and then applied to research the role of river discharge and wind effects under mesoscale currents and coastal dynamics at open ocean boundaries on the plumes interaction. The chosen period was the winter of 2009-2010. To examine the response of the estuarine plumes to different wind directions, five scenarios of moderate winds were considered blowing from each of the main four compass points, and with the absence of wind. Through the use of two distinct tracers, three different idealized scenarios were chosen: low, moderate and high Tagus and Sado river discharges. The results showed an evidence of estuarine plumes, filaments and mesoscale eddies caused by the interactions between the estuaries and the nearby coastal region. The obtained results also reveal a intrusion caused by the Sado plume in Tagus estuary after a 10-day simulation. This pattern was not observed for Tagus plume. It was also observed that the Sado estuarine water propagates to Tagus estuary in just 36 hours with coastal dynamics, when compared to the mesoscale currents forcing took around 120 hours. In summary, the model application developed in this study contributed to the characterization and understanding of the interaction between Tagus and Sado estuary’s, and in which conditions these occur.
Dada a proximidade entre os estuários do Tejo e do Sado, é reconhecido que as descargas destes estuários ocorrem na mesma região costeira. O conhecimento atual relativo à hidrodinâmica dos estuários do Tejo e do Sado resulta maioritariamente da exploração de resultados de modelos numéricos, que descrevem as propriedades físicas e padrões gerados pelas correntes de maré e descargas fluviais. Não obstante, verificou-se que a interação entre estes dois sistemas não é considerada, não havendo esforços no sentido de estudar os dois sistemas simultaneamente, bem como de descrever as relações que partilham e identificar as mútuas influências a nível dinâmico. Com este objetivo, foi implementado o modelo numérico tridimensional Delft3D-Flow, de forma a investigar a dinâmica do estuário do Tejo, do Sado e da região costeira adjacente. O modelo numérico foi calibrado e validado com a altura de maré, correntes, salinidade e temperatura da água, sendo aplicado para a investigação do efeito das descargas fluviais e do efeito do vento na interação das plumas destes estuários. O período escolhido para as simulações foi o Inverno de 2009-2010. Foram impostos dois tipos de forçamentos na fronteira aberta oceânica, um que comtempla as correntes de mesoescala e outro apenas a dinâmica costeira. Foram considerados cinco cenários para ventos moderados nos quatro principais quadrantes e para a ausência deste. Através do uso de dois traçadores distintos, foram escolhidos três cenários idealizados com descargas baixas, moderadas e altas dos rios Tejo e Sado. Os resultados evidenciaram a presença de plumas estuarinas, filamentos e eddies causados pela interação entre os estuários e a região costeira. Os resultados obtidos revelam ainda uma intrusão da pluma estuarina do Sado no estuário do Tejo após descargas fluviais significativas durante dez dias, contudo, este padrão não foi observado na pluma estuarina do Tejo. Foi ainda observado que a água estuarina do Sado se propaga para o estuário do Tejo em apenas 36 horas com apenas a dinâmica costeira, ao passo que com as correntes de mesoescala só se observou a intrusão após 120 horas. Sumariamente, o modelo desenvolvido para este estudo contribuiu para a caracterização e compreensão da interação entre os estuários do Tejo e Sado, e definição das condições em que esta ocorre.

Master of Arts
Department of Modern Languages
Amy L. Hubbell
Much of the critical work on Marie Cardinal's Les Mots pour le dire has focused primarily on the hysteria of the novel‘s narrator and her subsequent journey through psychoanalysis. More recently, research on the novel has expanded to include the issues of the narrator‘s pied-noir identity, nostalgia and memory. While such criticisms shed light on the intent of the novel, they do not necessarily explain the enigmatic and oftentimes overlooked final line of the text: "Quelques jour plus tard c‘était Mai 1968." In this thesis, I propose that this line is the key to understanding the novel; as such, I seek to re-examine Les Mots pour le dire through a feminist lens in order to explicate the seemingly malapropos reference to May 1968 and use it to explain central elements of the novel, including the narrator‘s madness, her tumultuous mother-daughter relationship and her eventual authorship. That the events of May 1968 represent one of the most subversive and socially destructive periods in recent French history as well as a giant shift towards the moral left establishes the value of revolt in Les Mots pour le dire. Specifically, I argue that Cardinal attacks the collusion of the ballasts of patriarchal society, religion, capitalism and class, and how these institutions have profited from the subjugation of women in society. When viewed in this light, the narrator‘s madness cannot simply be the product of her mother‘s psychological abuses. Instead, her madness and subsequent detachment from society symbolize the ultimate rejection of a world in which she finds herself oppressed and manipulated. She thus emerges not as a woman consumed by insanity but as a woman in revolt.

Cette thèse se place dans un contexte applicatif spécifique de la RFID (Radio Frequency Identification) UHF (Ultra-High Frequency) pour lequel un grand nombre de tags RFID est concentré dans un volume réduit. Ce contexte conduit à des configurations pour lesquelles les antennes associées aux tags sont fortement couplées. Dans ces conditions de fort couplage et de forte densité de tags, une antenne peut voir son impédance d’entrée désadaptée et son diagramme de rayonnement distordue. La conséquence de cette diminution des performances de l’antenne tag est la réduction globale du taux de lecture des tags liée à la dégradation du bilan de liaison individuel entre certains tags et l’antenne lecteur. Afin d’appréhender ce problème fortement aléatoire du fait de la distribution à priori inconnue des tags, il est nécessaire de développer une méthode statistique robuste. Pour atteindre des temps de simulation raisonnables malgré un grand nombre de réalisations de distributions aléatoires de tags, l’approche choisie dans cette thèse est de modéliser les antennes tags et le couplage entre antennes par des antennes dipôles grâce à des modèles analytiques basés sur la méthode IEMF. Ces dipôles peuvent être chargés sur des impédances adaptées ou non pour s’approcher du cas réel d’antennes tags chargées par l’impédance d’entrée des puces RFID. Les modèles analytiques sont validés par des méthodes numériques et des mesures. Les analyses statistiques des données concernent la désadaptation en impédance et le gain dans la direction du lecteur. Des analyses statistiques sont également effectuées sur des simulations de tags commerciaux avec une corrélation satisfaisante avec les résultats de dipôles. A terme, ce travail de thèse portant sur le « comportement de groupe » d’antennes doit fournir les outils d’analyse et de synthèse nécessaires pour évaluer la robustesse d’un design d’antenne RFID dans un environnement proche caractérisé par une forte densité de tags et un fort couplage
This context of this thesis is that of UHF RFID use cases where a large number of RFID tags is concentrated in a limited volume. This context leads to scenarios in which the tag antennas can be strongly coupled electromagnetically. Under the conditions of high coupling and high density of tags, an antenna can be mismatched and its radiation pattern distorted. As a result of the antenna’s loss of performance, a global reduction of the tags reading rate can be observed as well as a drop of the reading distance for some of the tags. In order to tackle this highly random problem flowing from the unknown distribution of tags, the approach developed in this work is to assume that the electromagnetic coupling between antennas can be modeled by analytical formulas of self and mutual impedances valid for straight resonant dipoles. These dipoles can be loaded by complex impedances corresponding to the chip input impedances of real commercial RFID tags. The analytical models are validated by numerical simulations and experimental results. Statistical studies are performed for a large number of dipole distributions in terms of impedance mismatch and embedded gain variations in the direction of the reader. A statistical analysis of simulated commercial tags is also performed showing a good correlation with the dipole statistics. In the future, this work on the “group behavior” of antennas should provide the analysis and synthesis tools required for a robust evaluation of the tag performances in an environment characterized by a high tag density

L’emballage intelligent (EI) est une technologie émergente basée sur la fonction communicative des emballages. La radio-identification (RFID) est considérée comme le concept le plus prometteur de l’EI. La RFID fait référence aux technologies et systèmes qui utilisent les ondes radio (sans fil) pour transmettre et identifier de manière exclusive et/ou suivre des objets avec une information précise en temps réel.Cette thèse est basée sur une recherche innovante des propriétés électriques (capacité, permittivité réelle et perte) de la protéine de soja isolée, de la gélatine et du caséinate de sodium, et vise leur utilisation comme capteurs de température, associés à l’étiquette RFID. Les variables étaient la température (20°C jusqu’à 80°C) et l’humidité (90% HR) qui sont normalement utilisées pour la cuisson de la viande. La gélatine s’est révélée être le capteur le plus sensible. Après cette partie, plusieurs étapes ont été menées :• L’analyse de l’impact de l’épaisseur du film de gélatine sur la capacité et la détermination de plusieurs paramètres tels que la sensibilité, l’hystérésis et la répétabilité;• La couverture de gélatine sur l’étiquette RFID, testée à 90% HR et à température variable (de 20°C à 80°C) en condition pilote. L’impact sur la bande de lecture a été analysé.Le potentiel de la gélatine en tant que capteur a été démontré à une épaisseur de 38 µm à laquelle la capacité était stable de 20°C à 80°C et à Ultra-Haute Fréquence (300-900 MHz). L’échantillon de 125 µm a subi une dégradation électrothermique entre 60°C et 80°C. Pour surmonter ce phénomène, 600 MHz ont été appliqués. Un équilibre entre l’épaisseur et la fréquence devrait être considéré pour augmenter la sensibilité qui était de 0,14 pF/°C (125 µm à 600 MHz) et 0,045 pf/°C (38 µm à 868 MHz), influençant les résultats lors de la simulation de cuisson de la viande. La réutilisation du même capteur a conduit à une perte de masse réduisant la sensibilité. L'étiquette RFID couverte d’un film de gélatine sur l'antenne a pu donner de différence significative (p <0,05) dans la bande de lecture théorique (BLT) à 868, 915 et 960 MHz. Également dans cette layout, la BLT a été la même pour la même température croissante et décroissante (pas de hystérésis) dans la zone critique (60°C-80°C et 60°C-20°C) à 915 MHz. Ces résultats prometteurs ouvrent une porte à une nouvelle conception de capteurs de température basés sur les biomatériaux, renouvelable at à faible coût, couplé avec des étiquettes RFID passives pour l’emballage intelligent
Intelligent packaging (IP) is an emerging technology based on the communication function of packages. Radio frequency Identification (RFID) is considered the most promising concept of IP. RFID refers to technologies and systems that use radio waves (wireless) to transmit and uniquely identify and/or track objects with accurate information in a real time.The present thesis is based on an innovative study of the electrical (capacitance) and dielectric properties (real permittivity and loss factor) of soybean isolated protein, gelatin and sodium caseinate aiming at their use as a sensor of temperature coupled with RFID tags. The environmental variables were temperature (range from 20°C up to 80°C) and humidity (90% RH) that are normally used for meat cooking. Gelatin was the most sensitive sensor. After this first part, several steps have been set up:• Analysing the impact of gelatin film thickness on electrical capacitance and the determination of several parameters such as sensitivity, hysteresis and repeatability;• The coating of gelatin on a RFID tag tested at 90% RH and variation of temperature (20°C up to 80°C) in a pilot condition. The impact on the reading range was analysed.The potential of gelatin as a sensor was demonstrated at thickness of 38 µm and 125 µm. For the first case, the capacitance was stable at 20°C up to 80°C and at Ultra High Frequency band (300-900 MHz). Sample with 125 µm has suffered the electro-thermal breakdown between 60-80°C. To overcome this phenomenon, 600 MHz was applied. A balance between thickness and frequency should be consider to increase the sensitivity that was 0.14 pF/°C (125 m at 600 MHz); this value was higher than 0.045 pF/°C (38 m at 868 MHz) influencing the results in the simulation of meat cooking. Reuse of the same sensor has led to mass loss reducing the sensitivity. The feasibility of gelatin sensor-enable RFID tag was demonstrated. The tag covered by gelatin film in the whole antenna was suitable because it was able to deliver different Theoretical Reading Range (TRR) (p<0.05) for 868 MHz, 915 MHz and 960 MHz. At this layout also, the TRR was the same (without hysteresis) for the rising and descending temperature at the critical zone (60°C- 80°C and 60°C-20°C) at 915 MHz. These promisor results open a window for new conception of temperature sensor based on biomaterial that confers advantages, such as low cost and eco-friendly property sought to be interfaced to passive RFID tags for intelligent packaging

La proliferation cellulaire, element important dans le developpement et la dissemination des tumeurs peut etre calculee en utilisant une reaction immunohistochimique sur coupes tissulaires congelees avec l'anticorps monoclonal ki-67. Le pourcentage de surface nucleaire marquee est mesure par 2 analyseurs d'image (tas et samba 2005), et applique a 32 lm b et 46 lm t. Ce parametre est hautement correle au nombre de cellules positives. - l'analyse d'image permet des mesures objectives plus rapides, sur des territoires plus larges et strictement lymphomateux, que le comptage manuel des cellules positives et negatives habituellement utilise; ceci est realisable en pratique avec le samba 2005 et au mieux avec reaction immunohistochimique en 3 couches de type alcaline phosphatase/fast red. - des differences significatives sont observees entre les lm de faible et de haut grade de malignite, classes selon la classificaiton de kiel. La formulation internationale est revisee par l'analyse de variance, reproduisant la classification de kiel. Les lm t de type lymphadenopathie-angio-immunoblastique, classes dans les lm de faible grade, ont des valeurs semblables aux lm t pleomorphes a cellules de moyenne et/ou de grande taille, de haut grade; - un grand ecart des valeurs est observe particulierement au sein de 3 types de lm dont l'evolution clinique est variable: ceci incite a etudier ce parametre en tant que facteur pronostique, sur un plus grand nombre de cas

Anorexia nervosa is an eating disorder whose onset emerges at an increasingly early age and whose prognosis, even among adolescents, can be grave. Current scientific literature and practice guidelines on the treatment of adolescent patients with anorexia point to the key role that is played by parents and family in influencing the therapeutic possibilities and the outcomes of young patients. The aims of the thesis are to explore the relational and emotional dynamics in families of adolescents with anorexia that may influence the treatment possibilities and the outcome of the young patients. Three different research studies are presented in the thesis, all examined families of adolescents with restricting type anorexia nervosa, and explored aspects of family relations, relating in particular to the internalized parental bonding, emotion regulation and triadic mother-father-daughter interactions. The first study aims to identify any specific pattern of parental bonding and address the intergenerational transmission of these patterns in families of newly diagnosed adolescents with restricting type anorexia. The second study instead deals with emotion regulation in families with an adolescent with anorexia, exploring alexithymia in the daughter, mother and father based on clinical versus self- assessment. Whereas in the third study, a direct observational procedure based on a videotaped play section was used to explore triadic interactions. The results of the studies seem to suggest that both in the research, as well as in treatment of patients with anorexia nervosa, attention needs to be shifted from the exclusive mother-daughter relation to the involvement of the father, of the parental couple and of the family as a whole. Since family functioning is well established as a maintaining factor of anorexia nervosa or vice versa as a facilitating factor in the therapeutic process, studying the family relations may not only help clinicians to select the most suitable treatment for each patient and each family but also to predict the possibility of establishing a therapeutic alliance with the family and thus to improve the possibility of reaching a good outcome.
L’anoressia, patologia eclatante nelle sue manifestazioni eppure sfuggente, paradossale ed inquietante, tentativo di redenzione e rischio di morte allo stesso tempo, pone ai suoi clinici e ai suoi teorici questioni di grande complessità, che si riflettono nella varietà delle teorie differenti e contraddittorie formulate nei diversi ambiti. Patologia di confine fra il somatico e lo psichico, l’anoressia ha da sempre suscitato il dibattito fra i sostenitori delle origini psicologiche della malattia e coloro che invece parteggiano per cause primariamente organiche. L’anoressia nervosa, la più studiata e la più nota fra le forme di disturbo del comportamento alimentare, conserva anche nell'età evolutiva aspetti di prognosi molto grave con un’elevata percentuale di esito mortale. Nonostante l’età di esordio dell’anoressia nervosa sia sempre più precoce e la prevalenza del disturbo in età evolutiva in crescita, sono ancora carenti gli studi in letteratura che riguardano specificamente questa fascia d’età. Eppure ben il 40% dei nuovi casi di anoressia esordisce proprio fra i 15 e i 19 anni, età in cui si rilevano tuttavia anche i più elevati tassi di guarigione. Nelle prime fasi del suo esordio, che avviene di solito in adolescenza, appare perciò cruciale predisporre una presa in carico precoce e tempestiva di questo disturbo dagli esiti potenzialmente molto gravi. L’insorgenza del disturbo, la cui eziologia appare complessa e multifattoriale, sembra precipitata dall'interazione di diversi fattori: biologici, psicologici, ambientali, culturali e sociali. Se i dati riguardanti le componenti genetiche e neurobiologiche sembrano offrire per ora limitate prospettive per un reale progresso nel trattamento di questa complessa patologia, più interessanti sul piano clinico e terapeutico appaiono attualmente i dati della letteratura che indicano il ruolo cardine delle componenti famigliari, sia per quanto riguarda l’evoluzione del disturbo sia per quanto riguarda gli indirizzi terapeutici valutati come più efficaci. Se è noto che i trattamenti familiari si sono dimostrati molto efficaci nel trattamento di questa psicopatologia, i meccanismi di funzionamento di queste terapie e le peculiari dinamiche familiari cui indirizzare più fruttuosamente il trattamento restano campi potenzialmente fertili, da esplorare per la ricerca. E’ convinzione generale che il complesso problema della eziopatogenesi rimanga al di fuori degli obiettivi degli studi volti ad analizzare e fotografare le dinamiche familiari presenti in un determinato momento nelle famiglie delle pazienti con anoressia. Tuttavia - obiettivo forse prioritario rispetto ad ogni altro - cogliere e descrivere il funzionamento delle pazienti con anoressia all'interno delle loro famiglie può essere utile e forse indispensabile per stabilire quali siano le misure terapeutiche più valide da attivare in ogni specifico caso. Una presa in carico tempestiva ed efficace di questa grave psicopatologia, potenzialmente mortale, può essere fondamentale e la ricerca in questo campo può arricchire in maniera sostanziale il ventaglio degli interventi disponibili e l’efficacia della loro applicazione alle diverse situazioni cliniche. Questa tesi si propone di esplorare all'interno delle famiglie di adolescenti con anoressia alcune dinamiche relazionali ed emotive che potrebbero influenzare il decorso e le possibilità di cura delle giovani pazienti. Nella tesi sono presentati tre diversi lavori di ricerca, svolti tutti all'interno di famiglie di adolescenti con anoressia nervosa di tipo restrittivo, volti ad esaminare aspetti delle relazioni familiari, relativi in particolare ai legami genitoriali interiorizzati, alla regolazione emotiva e alle interazioni madre-padre-figlia. Il primo studio esamina il legame genitoriale percepito dalle adolescenti con anoressia e dei loro genitori, nell'intento di cogliere la possibile continuità e influenza degli stili di attaccamento tra le diverse generazioni (genitori verso i propri genitori – figli verso i genitori) all'interno delle famiglie dei pazienti. La ricerca sulla potenziale trasmissione trasgenerazionale dei legami parentali e dell’attaccamento è infatti ancora molto limitata e non vi è inoltre alcuna evidenza che riguardi le famiglie di pazienti adolescenti. Questo studio controllato ha visto la partecipazione di 168 partecipanti, adolescenti e genitori, cui è stato somministrato il Parental Bonding Instrument (PBI) per la valutazione dei legami genitoriali interiorizzati. L’analisi dei legami parentali dei membri della famiglia, svolta a livello latente (Latent Class Analysis), ha permesso di evidenziare alcune peculiarità a livello familiare. Se da una parte i risultati dello studio confermano che gli adolescenti con anoressia restrittiva riferiscono di percepire positivamente il rapporto con i propri genitori, dall'altra i genitori dei pazienti mostrano di ricordare i propri genitori come apprensivi e autoritari ma non particolarmente affettuosi. Tali specificità del legame parentale ricordate dai genitori dei pazienti rispetto ai propri genitori aprono la questione di quanto i modelli di attaccamento genitoriali possano influenzare la relazione stessa con i figli e dunque essere possibili target di un intervento volto a modificare in senso migliorativo le relazioni all'interno delle famiglie dei pazienti con anoressia. Ulteriori ricerche sui modelli di attaccamento nelle famiglie di pazienti con anoressia potrebbero chiarire l’eventuale ruolo di questi modelli come fattore di vulnerabilità rispetto ai disturbi alimentari e soprattutto la loro influenza rispetto al decorso della malattia. D’altra parte il disegno trasversale dello studio non permette di chiarire se le percezioni genitoriali negative rispetto al legame con i propri genitori preesistano alla malattia della figlia o se invece siano conseguenza di quest’ultima. Le relazioni in atto e le esperienze successive possono infatti influenzare i ricordi e le rappresentazioni del passato e ciò specialmente nel caso di esperienze fortemente traumatiche come può essere per i genitori delle pazienti la diagnosi di anoressia delle figlie con il concreto pericolo di vita che spesso essa comporta. Questa considerazione rende conto dell’importanza di studiare le percezioni interne dei genitori e delle figlie, superando la sterile e probabilmente insolubile controversia su quali siano le cause e quali le conseguenze. Dal punto di vista della cura considerare la reciproca e vicendevole connessione tra rappresentazioni interne (per esempio le rappresentazioni del legame con i genitori del passato) e le relazioni e le interazioni attuali offre infatti due importanti punti di accesso al lavoro terapeutico con le famiglie: se da una parte il lavoro sulle rappresentazioni può favorire la modificazione dei comportamenti genitoriali e delle interazioni reali fra genitori e figlie malate, dall'altro è altrettanto vero che lavorare direttamente sulle relazioni concrete in corso fra genitori e figli può giungere a modificare anche le rappresentazioni interne di questi rapporti. Da qui l’interesse di studiare non solo le rappresentazioni interne dei legami familiari ma anche le interazioni in atto fra genitori e figlie (terzo studio di questa tesi) e la regolazione delle emozioni all'interno della famiglia (secondo studio), aspetto quest'ultimo che potrebbe collegare le due dimensioni del mondo interno delle rappresentazioni e della realtà esterna delle interazioni. Le rappresentazioni di sé e dell’altro (modelli operativi interni di attaccamento) sono infatti strettamente connesse alla regolazione, più o meno funzionale, degli affetti ed ai comportamenti parentali messi in atto nel concreto. Il secondo studio, presentato nella tesi, si occupa quindi di esaminare le potenziali peculiarità del funzionamento psichico dei membri delle famiglie di pazienti con anoressia in relazione alla qualità della percezione e del contatto col mondo emozionale interno, utilizzando il costrutto di alessitimia. Molti studi sull'anoressia nervosa si sono concentrati sulla regolazione emotiva, ed in particolare sull'alessitimia, a livello individuale, mentre ci sono solo pochi e contrastanti dati sull'alessitimia a livello famigliare, nonostante le evidenze più recenti segnalino l'importanza delle dinamiche familiari rispetto all'evoluzione del disturbo anoressico, soprattutto nei pazienti adolescenti. Si è ritenuto opportuno in questo secondo studio non limitarsi all'indagine delle percezioni interne di pazienti e genitori rispetto alla qualità dei propri vissuti emotivi attraverso questionari autovalutativi, ricorrendo in aggiunta ad una valutazione clinica svolta attraverso un’intervista strutturata specificamente studiata per valutare l’alessitimia. L'alessitimia rappresenta infatti uno specifico deficit nella regolazione degli affetti che implica proprio una difficoltà nell'identificare, elaborare e descrivere verbalmente le emozioni, che si accompagna di solito ad un limitata capacità immaginativa e fantasmatica. Lo scopo dello studio è stato dunque quello di valutare l’alessitimia nelle pazienti adolescenti anoressiche e nei loro genitori, utilizzando una misurazione multi-metodo al fine di acquisire una conoscenza più diretta e approfondita del problema. A 46 partecipanti, pazienti adolescenti con anoressia e genitori, è stata proposto il noto questionario self-report Toronto Alexithymia Scale (TAS-20), accanto all’intervista strutturata Toronto Structured Interview for Alexithymia (TSIA), che rappresenta la prima intervista clinica strutturata completa per la valutazione dell’alessitimia. L’uso del modello a tratti latenti di Rasch ha permesso di confrontare la sensibilità dei due diversi strumenti, evidenziando una significativa discordanza fra i due: l’intervista clinica infatti permette di riscontrare un grado di alessitimia maggiore sia nei genitori sia nelle figlie con anoressia. Inoltre all’interno delle famiglie ed in particolare della coppia genitoriale è emerso un significativo divario nei livelli di alessitimia. Grazie all’utilizzo dell’intervista clinica, che si è dimostrata in grado di minimizzare le tendenze alla negazione, si è rilevato che i padri delle pazienti si trovano molto più in difficoltà nell’identificare, elaborare e descrivere verbalmente i propri sentimenti rispetto alle madri. Queste ultime si collocano piuttosto su una polarità opposta di grande recettività e capacità di comprendere e analizzare i sentimenti, che potrebbero all’opposto coinvolgerle eccessivamente fino talvolta a travolgerle. I risultati aprono la via a dare maggior spazio, accanto alle caratteristiche individuali di pazienti e genitori, anche all’impatto del funzionamento emotivo familiare (per esempio le antitetiche modalità materne e paterne di gestire e vivere le emozioni all’interno della coppia genitoriale), come aspetto fondamentale rispetto alla possibilità di stabilire un’alleanza terapeutica con paziente e genitori e dunque influenzare in senso positivo l’outcome. Gli studi più recenti e le linee guida per il trattamento di pazienti adolescenti con anoressia nervosa concordano infatti nel sottolineare il ruolo chiave svolto dai genitori per quanto riguarda gli esiti dei trattamenti per le giovani pazienti. Tuttavia il funzionamento familiare è stato per ora studiato quasi esclusivamente con metodi autovalutativi. Eppure, come è emerso nel secondo studio presentato, proprio nelle difficili circostanze vissute dalle famiglie che si trovano ad affrontare la malattia, spesso grave e pericolosa, della figlia che soffre di anoressia, le valutazioni cliniche e i metodi osservativi possono aiutare a riconoscere in maggior misura aspetti delle relazioni familiari e del funzionamento psichico dei membri della famiglia, che essi stessi non sono sempre in grado di cogliere appieno. Il terzo studio, che compone questa tesi, mira infatti ad indagare le interazioni triadiche all’interno delle famiglie di adolescenti con anoressia nervosa attraverso una procedura osservativa semistandardizzata. 120 genitori e figlie adolescenti, consecutivamente giunti all’attenzione di servizi neuropsichiatrici per l’età evolutiva, hanno partecipato allo studio e hanno preso parte ad una seduta di gioco videoregistrata, secondo la procedura del Lausanne Trilogue Play (LTP). In questa innovativa applicazione alle famiglie di pazienti con anoressia restrittiva, il Lausanne Trilogue Play segnala alcune peculiarità nell’interazione, che differenziano queste ultime famiglie da un altro gruppo di famiglie con figlie diagnosticate come sofferenti di disturbi psichiatrici differenti (disturbi dell’umore di tipo depressivo o disturbi d’ansia), le quali hanno preso parte allo studio come gruppo di controllo con altra psicopatologia. I risultati mostrano che nelle famiglie delle pazienti con anoressia i ruoli all’interno della triade madre-padre-figlia non sono sempre chiari e definiti e ciò soprattutto quando è richiesta una rilevante capacità di triangolazione e di coinvolgimento di tutti e tre i protagonisti nell’interazione. Il rapporto sembra infatti più spesso mantenuto a livello diadico attraverso la creazione di coalizioni familiari. I genitori mostrano una notevole difficoltà a ritagliarsi uno spazio relazionale di coppia da cui la figlia malata possa essere momentaneamente esclusa. Il padre è posto o tende a porsi lui stesso ai margini dell’interazione fra madre e figlia, rimanendone spesso escluso. Padre e figlia si collocano inoltre su una polarità di maggior autocontrollo e distacco emotivo, aliena alle madri che mostrano invece una maggiore reattività e un più marcato coinvolgimento. Il presente lavoro, essendo controllato, fornisce indicazioni in linea con la medicina dell'evidenza, anche se con un grado di evidenza inferiore a quello fornito da un trial controllato randomizzato. Ad esempio si dimostra la presenza di caratteristiche di funzionamento famigliare in cui il padre acquisisce un ruolo di primo piano, suggerendo dunque l’opportunità di spostare l'attenzione dall’indagine dalla relazione esclusiva madre-figlia al coinvolgimento del padre, della coppia dei genitori e della famiglia nel suo complesso. Dal momento che proprio il funzionamento familiare può rivelarsi un fattore di rischio o viceversa un fattore di facilitazione del processo di cura, l’utilizzo della metodica LTP può consentire l’osservazione diretta delle dinamiche familiari, aprendo la via ad un eventuale lavoro terapeutico mirato su queste ultime. Lavorare sugli elementi disfunzionali delle interazioni attuali, che siano acquisiti dopo l’esordio della malattia oppure antecedenti, può infatti mobilizzare le relazioni familiari, favorendo un outcome positivo per la giovane paziente. Con la consapevolezza del rischio di operare un’indebita trasformazione dei risultati dell’osservazione diretta in dati di fatto assoluti, interpretati poi a vantaggio di letture eziopatogenetiche dell’anoressia, diviene necessario sottolineare che in un campo di studio così complesso e articolato, come quello della psicopatologia dell’anoressia nervosa e delle relazioni familiari, la ricerca scientifica, e così i dati presentati in questa tesi, non possono che offrire risultati sempre limitati e destinati a ulteriori arricchimenti, conferme e disconferme. I tre studi presentati in questa tesi rappresentano un tentativo di cogliere e analizzare, con metodologie diverse e complementari, alcuni aspetti del funzionamento familiare pressochè inesplorati per quanto riguarda i pazienti adolescenti. I tre studi convergono nell’indicare che la coppia genitoriale e l’ambiente famigliare nel suo complesso possono avere un ruolo chiave rispetto alle possibilità evolutive e di cura delle giovani con anoressia. Non a caso il trattamento familiare, trattamento di prima linea raccomandato dalle linee guida internazionali, è particolarmente efficace proprio per le pazienti nella fascia di età adolescenziale e con recente esordio di malattia. Una miglior comprensione delle dinamiche familiari può essere prioritaria proprio per la cura di pazienti che non hanno ancora concluso il proprio sviluppo, anche dal punto di vista psicologico, e che vivono inoltre ancora all’interno della propria famiglia di origine. In adolescenza infatti il gioco di rimandi fra realtà esterna e realtà interna, fra genitori reali e imago parentali interiorizzate è ancora fluido e aperto. Il processo di soggettivazione stesso, l’evolversi del mondo interno dell’adolescente si gioca in questa complessa articolazione di relazioni ed emozioni, attuali e interiorizzate (Jeammet, 2010).

碩士
國立成功大學
光電科學與工程學系
104
The core-satellite nanostructures are applied to enhance electric field in SERS (Surface enhanced Raman scattering) tags. The method using electrostatic induction to produce core-satellite nanostructures is offered in this research. This method is simpler than those using DNA. The stability of Raman signal and whether the signal can be quantitative analysed depends on the stability and dispersion of nanostructures. There are several methods for improving the stability and dispersion of nanostructures in this research. Also, the purification of core-satellite nanostructures are provided in this research. The Raman signal’s intensity of a SERS tag depends on the number of satellites per core. The more satellites it has, the stronger Raman signal’s intensity it has. In this research, several chemicals were experimented for improving the number of satellites per core. Furthermore, the dispersion of the core-satellite nanostructures was improved by adjusting the satellites concentration and the method of mixture. The core-satellite nanostructures would be destroyed by the change of environment. Therefore, the core-satellite nanostructures was coated by silica chell in this research. The factors which would influence the dispersion or stability of the nanostructures were discussed in this research. In addition, the Raman signal of the core-satellite nanostructures with silica shell was measured in this research. The Raman signal of the single core-satellite nanostructure was measured successfully which could be applied to quantitative analysis.

Complex biological samples such as serum contain thousands of proteins and other molecules spanning up to 13 orders of magnitude in concentration. Present measurement techniques such as protein microarrays and quantum dot FRET do not permit the analysis of all pair-wise interactions between the components of such a complex mixture to a given target molecule. In this thesis, we explore the use of nanoparticle tags which encode the identity of the molecule to obtain the statistical distribution of pair-wise interactions using their Localized Surface Plasmon Resonance (LSPR) signals. The encoding is done through choice of shape, size and material of the nanoparticles. Protein interactions produce plasmonic coupling between pairs of such particles which are well resolved in the scattering spectra. In this thesis, we analyze the multiplexing capacity of such an approach and compare it with a FRET based method. It is observed that multiplexing capacity is significantly higher for plasmonic coupling based method proposed in this thesis compared to the use of commonly available FRET pairs. One of the practical disadvantages of single nano-particle resolved plasmonic sensing is the low scattering intensity causing a deteriorated signal to noise ratio of detection. As part of this work, we investigated the effect of substrate on light scattering from the nanoparticle and showed that high reflectivity substrates with field reflection coefficients approaching unity result in nearly an order of magnitude enhancement of scattered light intensity. Going further on the practical realizations of plasmonic sensors, we analyzed Grating Coupled Surface Plasmon Resonance (GC-SPR) sensors based on commercially available DVD gratings using Rigorous Coupled Wave Analysis (RCWA) technique implemented in the numerical package R-Soft. We showed that by using a multi-layer dielectric coating the linewidth of the plasmonic response can be reduced by more than an order of magnitude, consequently enhancing the limit of detection of the DVD based sensor.

碩士
國立交通大學
電信工程系所
95
Radio frequency identification (RFID) has received much attention.The RF to DC conversion efficiency is crucial for long range application in UHF band.The front end of the passive tag combined with the broadband antenna at 915MHz is investigated. Two subjects of high efficient charge-pump and antenna matching are focused in this study. This AC/DC charge-pump circuit is manufactured by TSMC 0.18um process.The multiplier factor is 8.575 for ten stage conversion.It can perform well at 0~80℃ and at 915MHz~2.4GHz.The dc voltage is regulated to 850mV with input power lying between -6~6dBm.Its Rising Time and Falling Time are 1.3776ms and 8.6546ms, respectively.Based on the Inductively-coupled mechanism, its bandwidth achieves 626MHz.The antenna gain is 2.701 dbi centered at 915MHz.Under complex conjugate matching between antenna and charge pump, the measured range can reach 4.3m with stable DC output voltage equal to 1.3V.

碩士
國立臺灣科技大學
資訊管理系
98
In Radio Frequency Identification (RFID) systems, the reader identifies tags through communication over a shared wireless channel. When multiple tags transmit their IDs simultaneously, their signals collide, increasing the identification delay. One important approach of the RFID tag identification protocol is Query Tree protocol (QT). In general RFID applications, a RFID system has a database, which owns all tag IDs that possibly occur. Thus, we consider the case that the RFID system has this knowledge and propose a Query Tree protocol with Shortcutting and Couple-resolution techniques (QTSC). From the database of RFID system, QTSC constructs a knowledge-based query tree, which stores each query that can identifies each tag stored in the database. Then, QTSC not only uses the shortcutting technique, which searches this knowledge-based query tree to skip many redundant queries, but also adopts the couple-resolution technique to couple two tags by simultaneously transmitting two ID prefixes from the reader for reducing the identification delay time. Our simulation results show that QTSC obviously outperforms QT and the previous method, namely, Knowledge-based Query Tree protocol (KQT).

L’étude de l’assemblage et de l’acheminement à la membrane plasmique des complexes de signalisation des RCPGs va jouer un rôle crucial dans le développement de nouveaux médicaments ayant moins d’effets secondaires. Des outils permettant l’étude de ces phénomènes existent déjà, mais un outil polyvalent qui permettrait d’étudier plusieurs aspects pourrait grandement faciliter et accélérer ces études. L’étiquette SNAP est un candidat intéressant puisqu’avec cette étiquette il est possible de marquer une seule construction avec une variété de différents substrats. Une construction encodant pour le récepteur β2AR avec une étiquette SNAP à son extrémité C-terminale a été ingénérée. Cette construction est apte à lier son ligand, à être acheminée à la membrane plasmique et à homodimériser. La protéine exprimée a été marquée avec le fluorophore BG-430. De la fluorescence non spécifique a été détectée dans la cellule (même en absence de l’étiquette SNAP sur le récepteur). Un essai BRET a été développé, utilisant la construction HA-β2AR-SNAP en tant qu’accepteur et est fonctionnel. L’étiquette SNAP, comme utilisée ici, ne présente pas un aussi bon candidat qu’attendu, puisque le substrat n’ayant pas réagi demeure coincé dans la cellule. Le facteur activateur de plaquette (PAF) et son récepteur (PAFR) jouent un rôle critique dans plusieurs réponses inflammatoires et le récepteur FP est impliqué dans l’accouchement prématuré. Une meilleure compréhension des complexes de signalisation associés à ces récepteurs pourrait être la première étape dans la compréhension de leur signalisation dans des situations normales ou de maladies. Des expériences de BRET étudiant des interactions de bases entre les récepteurs et leurs partenaires d’interactions connus ont été réalisées. Elles ont permis de déterminer que : les récepteurs PAF et FP homodimérisent, que les récepteurs PAF et FP hétérodimérisent, que les protéines Gβγ interagissent de manière constitutive avec ces récepteurs et qu’aucun signal de BRET n’a été détecté avec la protéine Gα et ce, en présence ou en absence de stimulation par un agoniste (suggérant qu’il est nécessaire d’optimiser le système présentement utilisé).
Studies of the assembly and plasma membrane trafficking of G protein-coupled receptor (GPCR) signalling complexes will play an important role in the development of new drugs with fewer side effects. Tools for this purpose have already been developed, but a more versatile tool which would allow assessment of multiple aspects of GPCR trafficking and protein/protein interaction could greatly facilitate and expedite these studies. The SNAP tag is without doubt an interesting candidate for this task. Using this tag, it is possible to label one receptor construct, with a variety of different substrates. A construct encoding the β2AR receptor was engineered with a C-terminal SNAP tag. This construct, when expressed in HEK 293 cells, was able to bind ligand, to traffic to the plasma membrane and to form homodimers. The expressed protein was then labelled with the BG-430 fluorophore. Non-specific fluorescence was detected in the cell, even in the absence of the SNAP tag. A BRET assay was developed using the HA-β2AR-SNAP as a BRET acceptor. The SNAP tag as used in this initial study was not as good as thought previously because uneacted substrate remains trapped in cells (i.e. the background was too high). Platelet-activating factor (PAF) and its receptor (PAF-R) play a critical role in many inflammatory responses and the receptor for prostaglandin F (FP) plays a role in pre-term labour. A better understanding of signalling complexes associated with these receptors might be the first step in a better understanding of their signalling in health and disease. As an initial step in this direction, we used BRET to study basic interactions between these receptors and known signalling partners. PAF-R and FP receptors homodimerize. A heterodimer between the FP and PAF receptors was also detected. Gβγ subunits interact with these receptors in a constitutive way. In the case of the Gα, no BRET signal was detected with or without agonist stimulation suggesting more work is required to optimize the system.