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From lymph node embryogenesis to homeostasis : new insights into the functions of stromal RANKL (TNFSF11) / Etude de l'influence du TNFSF11 (RANKL) sur le développment et homéostasie des organes lymphoïdes secondairesCordeiro, Olga 07 December 2015 (has links)
RANKL et RANK sont membres de la superfamille des TNF et de la superfamille des TNF-récepteurs, respectivement. Ils sont connus pour jouer un rôle important dans la régulation de la masse osseuse et dans le développement et la fonction du système immunitaire. Cependant des questions restent. Nous avons utilisé des souris génétiquement modifiées pour répondre à certaines de ces questions, en particulier en utilisant une souris dont les cellules stromales réticulaires marginales manquent RANKL dans les ganglions lymphatiques. Les résultats obtenus lors de cette thèse fournissent de nouvelles informations importantes sur l'impact positif de RANKL stromal sur les macrophages des ganglions lymphatiques concomitantes avec une fonction des cellules B amélioré et une pathogénicité virale réduit. Nous avons constaté que RANKL stromal régule l'expression de lymphotoxine et CXCL13, deux molécules clés de l'homéostasie des cellules B et de l'intégrité cellulaire des organes lymphoïdes secondaires. L’activité du RANKL semble suivre une hiérarchie temporelle sur lymphotoxine/TNFα, vu que le phénotype causé par le déficit en RANKL a une pénétrance augmenté avec l'âge. De plus, nous démontrons que RANKL active les cellules endotheliales lymphatiques des ganglions lymphatiques et on a trouvé que l'intégrine ITGA2b est un nouvel indicateur pour les cellules endotheliales lymphatiques activés. Ainsi, avec MAdCAM-1, ITGA2b sert comme un nouveau marqueur pour les cellules endothéliales lymphatiques qui sont constitutivement activés par le RANKL stromal. Au total, les données confirment l'importance de RANKL pour l'homéostasie des ganglions lymphatiques et dévoile les mécanismes ci-inconnus des fonctions de RANKL. À la lumière de cela et le fait que RANKL est sensible aux hormones féminines, nous avons étudié le rôle de RANKL dans le syndrome de Sjögren, une maladie inflammatoire chronique des glandes salivaires et lacrymales avec une forte polarisation de sexe féminin. Nous apportons la preuve que la neutralisation du RANKL réduit la taille des organes lymphoïdes tertiaire. En perspective, une éventuelle diaphonie entre les cellules endothéliales lymphatiques et les macrophages ou les cellules réticulaires marginales reste à clarifier. En outre, d'autres travaux sont nécessaires pour élucider le mécanisme par lequel RANKL stimule les maladies inflammatoires chroniques présentant des structures lymphoïdes tertiaires, afin de faire RANKL une nouvelle cible pour la thérapie. / RANKL and RANK are members of the TNF-superfamily and TNF-receptor superfamily, respectively. They are known to play an important role in the regulation of bone mass and in the development and the function of the immune system. However questions still remain. We have used genetically modified mice to address some of these questions, in particular by using a mouse whose lymph node marginal reticular stromal cells lack RANKL. The results obtained during this PhD provide important new insights into the positive impact of stromal RANKL on lymph node macrophages concomitant with enhanced B cell function and reduced viral pathogenicity. We found that stromal RANKL regulates lymphotoxin and CXCL13 expression, two key molecules for B cell homeostasis and secondarylymphoid organ cellular integrity. RANKL activity seems to follow a temporal hierarchy over lymphotoxin/TNFα, as the phenotype caused by stromal RANKL-deficiency has increased penetrance with age. Furthermore, we demonstrate that RANKL activates lymph node lymphatic endothelial cells and found that the integrin ITGA2b is a new indicator for activated lymphatic endothelial cells. Thus, together with MAdCAM-1, ITGA2b serves as a novel marker for those lymphatic endothelial cells that are constitutively activated by stromal RANKL. Altogether, the data reinforce the importance of RANKL for the lymph node homeostasis and uncover here to unknown mechanisms of RANKL functions.In light of this and the fact that RANKL is responsive to female hormones, we studied the role of RANKL in the Sjögrens syndrome, a chronic inflammatory disease of salivary and lacrimal glands with a strong female sex bias. We provide evidence that RANKL neutralization reduces tertiary lymphoid organ size. On the perspective side, a possible cross talk between lymph node lymphatic endothelial cells and macrophages or marginal reticular cells remains to be clarified.Furthermore, further work is required to elucidate the mechanism by which RANKL stimulates chronic inflammatory diseases presenting tertiary lymphoid structures, in order to make RANKL a new target for therapy.
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Topics In Effective Field Theories for the Strong InteractionThapaliya, Arbin 23 September 2016 (has links)
No description available.
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Estudo de dispositivos orgânicos emissores de luz empregando complexos de terras raras e de metais de transição. / Study of organic light-emitting devices using rare earth and transition metals complexes.Santos, Gerson dos 21 August 2008 (has links)
Neste trabalho foram projetados, fabricados e caracterizados funcionalmente dispositivos eletroluminescentes empregando complexos de Terras Raras (TR) e de Metais de Transição (MT) tanto como em filmes finos termicamente evaporados quanto formados através da técnica de spin-coating. O estudo foi iniciado com os complexos de TRs (especificamente o complexo de Európio e de Térbio) com filmes termicamente evaporados, com vistas à análise da eficiência externa dos dispositivos em função do ligante principal (CL). Desta análise observou-se que a particular estrutura química do CL resulta em diferenças perceptíveis ao nível da caracterização eletro-óptica (de 0,73x10-3 [BTA] para 1,05x10-3 [DBM]). Dando seqüência à análise de dispositivo com camada emissiva termicamente evaporada, foi realizada a análise do complexo de Térbio com dois tipos de ligante neutro (NL). Com base nos resultados obtidos, neste foco do estudo, observou-se que a configuração estrutural do NL implica em diferenças na eficiência externa (de 0,8x10-3 [PHEN] para 4,1x10- 3 [BIPY]) e no comprimento de onda dominante emitido (de 542 nm [BIPY] para 563 [PHEN]). Ainda explorando os complexos de TRs, foram estudados dispositivos empregando estes dispersos em um polímero com função de matriz, neste caso o polivinilcarbazol (PVK), em filmes formados por spin-coating, os quais apresentaram maior eficiência (de 0,72x10-3 [evaporado] para 1,24x10-3 [spincoating]) externa em comparação aos termicamente evaporados. Ainda nesta linha de estudo foi explorada uma nova estrutura de dispositivo empregando filmes automontados, cujos resultados apresentaram uma melhor eficiência externa para três bicamadas de PAni/PEDOT:PSS. Na seqüência, foram empregados os complexos de MT, especificamente de Rutênio e de Rênio, em filmes finos formados por spincoating. Com o primeiro destes, foi avaliada a conseqüência da variação do seu ligante, seus processos de transporte de portadores de carga e os fenômenos relacionados com sua luminescência. Já com o segundo, que foi disperso em PVK em diversas concentrações, foi feita a análise da eficiência externa com a mesma idéia adotada com o complexo de Európio, cujo estudo revelou uma eficiente transferência de energia, descrita pelo mecanismo de Transferência de Carga Metal- Ligante (3MLCT). / This work presents the study of the Rare Earth (RE) and Transition Metals (TM) complexes, as emissive layers of Organic Light-Emitting Devices (OLEDs) designed, built and electro-optically characterized. The thin films were thermally evaporated or spin-coated. This research started with the study of Europium complex changing its central ligand (CL), which showed that its electrical response exhibits external efficiency differences (from 0.73x10-3 [BTA] to 1.05x10-3 [DBM]). It was observed that the particular chemical structure of the CL results in significant differences as seen in the electro-optical characterization. Giving continuity to the thermally evaporated device characterization, an analysis was done with the Terbium complexes with two different neutral ligands (NL). It was noticed, in this work, that an NL change in Terbium complex imply in changes in external efficiency (from 0.8x10-3 [PHEN] to 4.1x10-3 [BIPY]) and in the emitted dominant wavelength (from 542 nm [BIPY] to 563 nm [PHEN]). Following the study using RE complex, we used it as a dye dispersed in polyvinylcarbazole (PVK) matrix, in a spin-coated deposited thin-film, which results showed a better external efficiency in comparison with thermally evaporated thin-films (from 0.72x10-3 [thermal evaporation] to 1.24x10-3 [spin-coating]). Besides, it was studied a new structure of electroluminescent device with thin-film Self-Assembled deposition, which results showed a better external efficiency for three bilayers of PAni/PEDOT:PSS. In the sequence, TM complexes, namely Ruthenium and Rhenium, were studied using spincoated thin-films. With the first of them, the implications of different ligands (bipyridyne and phenanthroline) were evaluated aiming the charge carrier transport and the luminescence related phenomena. The Rhenium complex was dispersed as a dye in the PVK, using the same approach as that used to study the Europium complex showing a very efficient energy transfer process, described in literature as the Metal-Ligand Charge Transfer (3MLCT) mechanism.
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Estudo de dispositivos orgânicos emissores de luz empregando complexos de terras raras e de metais de transição. / Study of organic light-emitting devices using rare earth and transition metals complexes.Gerson dos Santos 21 August 2008 (has links)
Neste trabalho foram projetados, fabricados e caracterizados funcionalmente dispositivos eletroluminescentes empregando complexos de Terras Raras (TR) e de Metais de Transição (MT) tanto como em filmes finos termicamente evaporados quanto formados através da técnica de spin-coating. O estudo foi iniciado com os complexos de TRs (especificamente o complexo de Európio e de Térbio) com filmes termicamente evaporados, com vistas à análise da eficiência externa dos dispositivos em função do ligante principal (CL). Desta análise observou-se que a particular estrutura química do CL resulta em diferenças perceptíveis ao nível da caracterização eletro-óptica (de 0,73x10-3 [BTA] para 1,05x10-3 [DBM]). Dando seqüência à análise de dispositivo com camada emissiva termicamente evaporada, foi realizada a análise do complexo de Térbio com dois tipos de ligante neutro (NL). Com base nos resultados obtidos, neste foco do estudo, observou-se que a configuração estrutural do NL implica em diferenças na eficiência externa (de 0,8x10-3 [PHEN] para 4,1x10- 3 [BIPY]) e no comprimento de onda dominante emitido (de 542 nm [BIPY] para 563 [PHEN]). Ainda explorando os complexos de TRs, foram estudados dispositivos empregando estes dispersos em um polímero com função de matriz, neste caso o polivinilcarbazol (PVK), em filmes formados por spin-coating, os quais apresentaram maior eficiência (de 0,72x10-3 [evaporado] para 1,24x10-3 [spincoating]) externa em comparação aos termicamente evaporados. Ainda nesta linha de estudo foi explorada uma nova estrutura de dispositivo empregando filmes automontados, cujos resultados apresentaram uma melhor eficiência externa para três bicamadas de PAni/PEDOT:PSS. Na seqüência, foram empregados os complexos de MT, especificamente de Rutênio e de Rênio, em filmes finos formados por spincoating. Com o primeiro destes, foi avaliada a conseqüência da variação do seu ligante, seus processos de transporte de portadores de carga e os fenômenos relacionados com sua luminescência. Já com o segundo, que foi disperso em PVK em diversas concentrações, foi feita a análise da eficiência externa com a mesma idéia adotada com o complexo de Európio, cujo estudo revelou uma eficiente transferência de energia, descrita pelo mecanismo de Transferência de Carga Metal- Ligante (3MLCT). / This work presents the study of the Rare Earth (RE) and Transition Metals (TM) complexes, as emissive layers of Organic Light-Emitting Devices (OLEDs) designed, built and electro-optically characterized. The thin films were thermally evaporated or spin-coated. This research started with the study of Europium complex changing its central ligand (CL), which showed that its electrical response exhibits external efficiency differences (from 0.73x10-3 [BTA] to 1.05x10-3 [DBM]). It was observed that the particular chemical structure of the CL results in significant differences as seen in the electro-optical characterization. Giving continuity to the thermally evaporated device characterization, an analysis was done with the Terbium complexes with two different neutral ligands (NL). It was noticed, in this work, that an NL change in Terbium complex imply in changes in external efficiency (from 0.8x10-3 [PHEN] to 4.1x10-3 [BIPY]) and in the emitted dominant wavelength (from 542 nm [BIPY] to 563 nm [PHEN]). Following the study using RE complex, we used it as a dye dispersed in polyvinylcarbazole (PVK) matrix, in a spin-coated deposited thin-film, which results showed a better external efficiency in comparison with thermally evaporated thin-films (from 0.72x10-3 [thermal evaporation] to 1.24x10-3 [spin-coating]). Besides, it was studied a new structure of electroluminescent device with thin-film Self-Assembled deposition, which results showed a better external efficiency for three bilayers of PAni/PEDOT:PSS. In the sequence, TM complexes, namely Ruthenium and Rhenium, were studied using spincoated thin-films. With the first of them, the implications of different ligands (bipyridyne and phenanthroline) were evaluated aiming the charge carrier transport and the luminescence related phenomena. The Rhenium complex was dispersed as a dye in the PVK, using the same approach as that used to study the Europium complex showing a very efficient energy transfer process, described in literature as the Metal-Ligand Charge Transfer (3MLCT) mechanism.
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Intraocular lenses with surfaces functionalized by biomolecules in relation with lens epithelial cell adhesion / Fonctionnalisation de lentilles intraoculaires acryliques par greffage de biomolécules limitant la cataracte secondaireHuang, Yi-Shiang 08 December 2014 (has links)
L’Opacification Capsulaire Postérieure (OCP) est la fibrose de la capsule développée sur la lentille intraoculaire implantée (LIO) suite à la dé-différenciation de cellules épithéliales cristalliniennes (LECs) subissant une transition épithélio-mésenchymateuse (EMT). La littérature a montré que l'incidence de l’OCP est multifactorielle, dont l'âge ou la maladie du patient, la technique de chirurgie, le design et le matériau de la LIO. La comparaison des LIOs en acryliques hydrophiles et hydrophobes montre que les premières ont une OCP plus sévère, médiée par la transition EMT. En outre, il est également démontré que l'adhérence des LECs est favorisée sur des matériaux hydrophobes par rapport à ceux hydrophiles. Une stratégie biomimétique destinée à promouvoir l’adhérence des LECs sans dé-différenciation en vue de réduire le risque de développement de l’OCP est proposée. Dans cette étude, les peptides RGD, ainsi que les méthodes de greffage et de quantification sur un polymère acrylique hydrophile ont été étudiés. La surface fonctionnalisée des LIOs favorisant l'adhérence des LECs via les récepteurs de type intégrine peut être utilisée pour reconstituer la structure capsule-LEC-LIO en sandwich, ce qui est considéré dans la littérature comme un moyen de limiter la formation de l‘OCP. Les résultats montrent que le biomatériau innovant améliore l'adhérence des LEC, et présente également les propriétés optiques (transmission de la lumière , banc optique) similaires et mécaniques (force haptique de compression, force d'injection de la LIO) comparables à la matière de départ. En outre, par rapport au matériau hydrophobe IOL, ce biomatériau bioactif présente des capacités similaires vis à vis de l’adhérence des LECs, le maintien de la morphologie, et l'expression de biomarqueurs de l’EMT. Les essais in vitro suggèrent que ce biomatériau a le potentiel de réduire certains facteurs de risque de développement de l’OCP. / Posterior Capsular Opacification (PCO) is the capsule fibrosis developed onto the implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LEC) undergoing Epithelial-Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including patient’s age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs show the former has more severe PCO after EMT transition. Additionally, the LEC adhesion is favored onto the hydrophobic materials compared to the hydrophilic ones. A biomimetic strategy to promote LEC adhesion without de-differentiation to reduce PCO development risk is proposed. RGD peptides, as well as their grafting and quantification methods on a hydrophilic acrylic polymer were investigated. The surface functionalized IOL promoting LEC adhesion via integrin receptors can be used to reconstitute the capsule-LEC-IOL sandwich structure, which is considered to prevent PCO formation in literature. The results show the innovative biomaterial improves LEC adhesion, and also exhibits similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties comparing to the starting material. In addition, comparing to the hydrophobic IOL material, this bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression. The in vitro assays suggest this biomaterial has the potential to reduce some risk factors of PCO development.
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Développement de nouveaux complexes organométalliques de métaux de transition polyvalents pour la scintillation et la chimie médicinale / Development of new versatile organometallic complexes for scintillation and medicinal chemistryElie, Margaux 06 October 2017 (has links)
Deux nouvelles familles de complexes de cuivre(I) cationiques, de formules [Cu(NHC)(N^N)][X] et [Cu(P^P)(N^N)][PF6], ont été synthétisées avec des ligands 2,2’ bis pyridyl pontés, chélates à six chaînons, facilement modulables. Ces complexes présentent des émissions à l’état solide centrées entre 455 et 520 nm (bleu à vert), avec de larges décalages de Stokes et des rendements quantiques pouvant atteindre 0,86. De plus, l’émission via un phénomène de fluorescence retardée activée thermiquement (TADF) a été prouvée pour les complexes [Cu(NHC)(N^N)][X]. Les premiers scintillateurs plastiques dopés avec des complexes de cuivre(I) détectant les radiations nucléaires de type gammas ont été obtenus avec des complexes de formule générale [Cu(P^P)(N^N)][PF6]. Les complexes de formule [Cu(NHC)(N^N)][X] ont permis l’obtention des premières Cellules Electrochimiques Luminescentes (LECs) émettant dans le bleu et incorporant des complexes de cuivre(I). Enfin, les complexes de formule [Cu(NHC)(N^N)][X] à ligand 2,2’ dipyridylamine présentent une activité cytotoxique envers différentes lignées de cellules cancéreuses et apportent la possibilité d’une action ciblée sur les cellules tumorales via l’ajout d’un vecteur. La polyvalence de ces complexes de cuivre(I) repose sur les ligands 2,2’-bis-pyridyl pontés, chélates à six chaînons, dont la synthèse est facile d’accès et les propriétés électroniques et structurales sont modulables. / New cationic copper(I) complexes of general formula [Cu(NHC)(N^N)][X] and [Cu(P^P)(N^N)][PF6] were developed with 6-membered-ring 2,2’-bis-pyridyl derivatives as ligand. These complexes exhibited blue (420 nm) to green (520 nm) emissions in solid state, with large Stokes shifts and photoluminescence quantum yields up to 0.86. Furthermore, the emission of the [Cu(NHC)(N^N)][X] complexes via a thermally activated delayed fluorescence (TADF) was demonstrated. The first plastic scintillators incorporating copper(I) complexes and detecting gamma radiations were obtained with [Cu(P^P)(N^N)][PF6] complexes. Application of the [Cu(NHC)(N^N)][X] complexes to the LEC technology led to the first copper(I)-based blue emitting device. In the last chapter, we also demonstrated that copper(I) complexes [Cu(NHC)(N^N)][X] bearing a 2,2’-dipyridylamine as N^N ligand exhibited high cytotoxycity against different cancer cells lines. These complexes paved the way for the design of a new type of copper(I) anti-cancer agents with the opportunity to increase the selectivity against cancer cells via a vectorization of the N^N ligand. The versatility of these copper(I) complexes demonstrated in this work relied on the easy to handle and highly modular 2,2’-bis-pyridyl ligands.
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Utilizing an efficient color-conversion layer for realization of a white light-emitting electrochemical cellVedin, Joel January 2016 (has links)
Organic semiconducting materials have received a lot of attention in recent years and can now be found in many applications. One of the applications, the light emitting electrochemical cell (LEC) has emerged due to its flat and lightweight device structure, low operating voltage, and possibility to be fully solution processed. Today LECs can emit light of various colors, but to be applicable in the lighting industry, white light need to be produced in an efficient way. White light on the other hand, is one of the toughest "colors" to achieve in an efficient way, and is of particular interest in general lighting applications, where high color-rendering index devices are necessary. In this thesis I show that blue light can be partially converted, into white light, by utilizing the photoluminescence of color conversion layers (CCLs). Furthermore, I show that a high color-quality white light can be attained by adopting a blue-emitting LEC with a CCL. Particularly, three different color-conversion materials were embedded onto a blue bottom-emitting LEC, to study the resulting spectrum. One of the materials, MEH-PPV, have good absorption compatibility with the electroluminescence of the blue emitters, but the materials photoluminescence do not cover the red to deep-red range of the spectrum. These parts of the spectrum are necessary to obtain high color rendering indices (≥80). A single layer of MEH-PPV adapted onto a blue-emitting LEC, led to a cold white LEC with CIE-coordinates x = 0.29, and y = 0.36, color-rendering index = 71, and correlated color temperature = 7200 K. These properties makes it potentially useful in outdoor-lighting applications. The photoluminescence of another studied color-converting material, polymer red, covers the red to deep-red range of the spectrum but the material lacks absorption in the green parts of the blue emitters electroluminescence spectrum. Thus it is necessary to combine it with MEH-PPV to be able to absorb all wavelengths from the blue-emitter and get a broad light-spectrum out of the device. In order to preserve a part of the blue light, a new device configuration was designed. It features a top-emitting blue LEC with a dual-layer CCL which reach an impressive color rendering index = 89 at a correlated color temperature = 6400 K (CIE-coordinates x = 0.31, y = 0.33). The color-rendering index is the highest reported for a white LEC. The absence of UV-, and IR-radiation, together with the high color rendering properties make the white LEC a possible candidate for even the most demanding lighting-applications, such as art galleries, and shop display windows, together with indoor lighting. In this thesis, I show that the CCLs function well. However, for the LECs to be worthy competitors, the efficiency and lifetime of the blue emitter need improvements.
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Changing from the silo model to the horizontal layers model in public policy regulations: the implications and potential for the telecommunications industrySpencer Logan, Lemuella C. 12 1900 (has links)
The end of the Twentieth Century and the start of the Twenty First Century has been a tumultuous time for the Telecommunications Industry. Even as it moves forward to embrace the new technologies the Industry finds itself embroiled in issues of governance. The Industry finds itself in a dilemma since innovations increase at a rate faster than the laws can be changed and these render its existing laws and policies to be in some cases obsolete and inappropriate for the reality of the present. In the past, the United States of America has relied on vertically integrated top down laws and methods of regulating all the different parts in its Telecommunications Industry. These laws are contained in the different numbered Titles of this Countrys Legal Codes. Since the inception of these laws, emphasis was placed in creating and documenting policies structured by industry, sector and type of content. This form of regulation is usually referred to as the Silo Method. However, in recent years, especially in the regulation of the Telephony industry, the method of law and rule formulation moved from content regulation to one in which the technologies are getting regulated in what has been described as a Layers Method. This paper first considered whether the Silo Method of regulation is in actuality the same as using the Horizontal Layers method and showed that this is the case. Then it determined that Enhanced Services are the same as Basic Services and that Telecommunications Services are the same as Information services and showed that given that the pair sets as noted were the same, it went on to conclude that all these services were essentially the same. While studying to some detail the technologies of VoIP, the paper also showed that VoIP although an Internet technology is similar to traditional telephony, and is both a Telecommunications Service and Information Service based on the definition as given in the law as well as the technologies that are used and that as a result of this, the current regulatory environment for this service with regards to telephony is inconsistent. It concluded that Telecommunications policies though now adequate may need to be modified.
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