A compreensão dos caminhos de desativação não radiativa em polímeros conjugados é fundamental para o uso desses materiais em dispositivos luminescentes, células fotovoltaicas e sensores. Nesta tese, os processos não radiativos em filmes automontados de polímero luminescente foram investigados via análise da supressão de intensidade de fotoluminescência, utilizando a técnica de fluorescência estacionária, e através da medida do tempo de vida do estado excitado com fluorescência resolvida no tempo em arranjo de contagem de fótons. A camada emissiva constituída por poli(p-fenileno vinileno) (PPV) obtido da conversão térmica do precursor poli(cloreto de xilideno tetraidrotiofeno) (PTHT) apresentou tempos de vida entre 150 e 250 ps, e fraca dependência com o comprimento de onda de detecção da emissão. Na presença de uma monocamada contendo azocorante Vermelho do Congo (CR) ou ftalocianina tetrassulfonada de níquel (NiTsPc) atuando como receptor de energia foi observada supressão da fluorescência e encurtamento do tempo de vida (50-100ps). À medida que se aumenta a distância entre as camadas de doador e receptor via interposição de bicamadas de espaçador, a dinâmica do sistema tende à dinâmica de decaimento do estado excitado do PPV na ausência de receptor. A dependência da eficiência com a distância 1/r2 ou 1/r3 apontam para transferência de energia ressonante (RET) típica da interação plano-plano ou plano-camada. Os processos não radiativos foram também estudados em função da diluição de segmentos PPV dispersos em matriz de polieletrólito poli(cloreto de dodecildimetilamônio) PDAC. A diluição dos segmentos conjugados aumenta a eficiência quântica de emissão, torna o mecanismo de desativação mais lento (500 ps) e diminui a dependência do tempo de vida com o comprimento de onda de detecção, devido à menor eficiência dos mecanismos de desativação não radiativa. Na presença de uma camada receptora, a eficiência de transferência de energia é maior para amostras com segmentos mais diluídos indicando que esse mecanismo compete com os processos internos à própria camada emissiva. O tempo de vida aumenta em filmes com mais baixo grau de conjugação e a dependência com o comprimento de onda de emissão é mais forte. Em resumo, a técnica de automontagem se mostrou adequada para obter filmes com propriedades fotofísicas controláveis no nível molecular, que puderam ser estudadas com espectroscopias de fluorescência. / Understanding the pathway of excitation in conjugated polymers is important for using these materials as active layer in devices, photovoltaic cells and sensors. In this thesis, non-radiative processes in layer-by-layer (LbL) films were investigated with measurements of fluorescence quenching in steady-state fluorescence spectroscopy and of the singlet excited state lifetime using time-resolved fluorescence spectroscopy in a single photon counting (SPC) apparatus. The emissive layer of poly(p-phenylene vinylene) (PPV) obtained via thermal conversion of the soluble precursor poly(xylylidene tetrahydrothiophenium) chloride (PTHT) showed lifetime 150-250 ps and weak dependence on the emission wavelength. In the presence of an acceptor layer of either Congo Red (CR) or nickel tetrasulfonated phthalocyanine (NiTsPc) the PL intensity was quenched and the lifetime was shorter (50 -100 ps). Upon increasing the distance between the energy donor (PPV) and acceptor layers by interposing bilayers of inert polyelectrolytes the dynamics tended to the PPV dynamics. The distance-dependence of the energy transfer efficiency (1/r2 or 1/r3) points to a resonant process (RET) with a plane-to-plane or plane-to-slab interaction. The non-radiative processes were also studied for varying dilutions of the PPV segments in a matrix of the polyelectrolyte poly(dodecyl methylamonium chloride) (PDAC). This dilution increased the quantum efficiency and led to longer lifetimes (500 ps) owing to a less effective non-radiative energy transfer. When an energy acceptor layer is present, energy transfer is more efficient for the most diluted systems, indicating that such transfer competes with internal processes in the emissive layer. The lifetime increased in films with low degree of conjugation, for which there was a stronger dependence on the emission wavelength. It is concluded that the LbL methodology was suitable to obtain photophysical film properties that could be controlled at the molecular level, and investigated with varied fluorescence spectroscopies.

Made available in DSpace on 2015-04-14T14:41:23Z (GMT). No. of bitstreams: 1 431733.PDF: 1937133 bytes, checksum: f4fcf980828011732b02f93581dea988 (MD5) Previous issue date: 2011-03-31 / A ?poca atual explicita um contexto de tecnocracia, consumismo e predom?nio da imagem na sociedade. Deflagra a progressiva influ?ncia do meio digital na cultura e nos processos comunicativos, de modo que, das novas m?dias da Era Digital que coexistem com as pr?-digitais destaca-se o ciberespa?o. Por outro lado, as identidades e identifica??es v?m sofrendo modifica??es significativas advindas dos paradigmas p?smodernos. Assim, este trabalho procurou abordar a identidade visual nos suportes impresso e digital a partir do contexto atual, tendo como estudo de caso a Unimed Noroeste/RS. Buscou-se analisar a linguagem e a imagem na identidade visual da institui??o focalizando o impacto de cada suporte na comunica??o gr?fica, atrav?s do m?todo da ret?rica visual aliado a no??es de semiologia de Roland Barthes e teorias de formas. Percebeu-se que os suportes impresso e digital influenciam-se mutuamente em organiza??o e estrutura de informa??es, compartilhando c?digos culturais, por?m o ciberespa?o organiza as informa??es hierarquicamente e a partir de menus de escolha, dando ? identidade visual novas possibilidades de apresenta??o a partir de maior interatividade com o leitor e de recursos visuais que n?o s?o poss?veis no suporte impresso.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-03-29T12:52:31Z No. of bitstreams: 1 DIS_DANIEL_MULETALER_PINTO_COMPLETO.pdf: 613088 bytes, checksum: 1120699c03f85eb5116aa6082ac9f32a (MD5) / Made available in DSpace on 2016-03-29T12:52:32Z (GMT). No. of bitstreams: 1 DIS_DANIEL_MULETALER_PINTO_COMPLETO.pdf: 613088 bytes, checksum: 1120699c03f85eb5116aa6082ac9f32a (MD5) Previous issue date: 2016-01-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present thesis aims to analyze Milton Hatoum?s four long narratives from the observation of common traits in the family situation of the narrators. The innominate character in Relato de um Certo Oriente attempts to understand his mother's abandonment. In Dois Irm?os, Nael learns that his father is a member of the family in which he and his mother are aggregated, and the narrator has no doubt that the assumption of paternity will never be aired, for the very reason that the two will never be accepted as equals by this family. In Cinzas do Norte, Lavo?s parents die when he is still a child. As for Arminto, in ?rf?os do Eldorado, he was born to a mother who died during his birth, and the father does not hesitate to blame him for that. All of these narrators are somehow abandoned or orphaned. The interpretative hypothesis is that the status of narrators is intrinsically related to the very activity of narrating. This is because the one who has the task of telling a story must deal with the loss that the passage of time represents, for the access to the past is hindered by various situations, such as the death of those who witnessed the facts one wishes to narrate. The absence of the father, the mother or both, which characterizes Hatoum?s storytellers is consistent with this lack, a situation that affects the melancholic look that is directed to the past. Nevertheless, the melancholic state is overcome in the narrative process itself, a task that requires the organization of fragmentary reports and scattered memories as well as the collection of documents and objects from the past, all being set in a narrative. The image of melancholy associated with those who have to write is analogous to the condition of the translator, as Walter Benjamin problematized in The Task of the Translator, a text that appears as an interpretative aid, as well as the work of Suzana Kampff Lages, Walter Benjamin: tradu??o e melancolia, and Mourning and Melancholia, by Freud. The always fragmentary nature of memory, the degradation that the passage of time imposes on everything and everyone, characteristics that grant to Hatoum's novels the aspect of true inventories of ruins, gave rise to the search for a new theoretical framework in Benjamin, this time in The Origin of German Tragic Drama, and in some of his commentators. In Benjamin, I also found the overcoming of the melancholic condition through the translator / writer task, the same that happens to the narrators to which this study is dedicated. However, the analysis of Milton Hatoum?s novelistic production also provided an opportunity to attempt to interpret the narratological issues raised here from Time and Narrative, by Paul Ricoeur, especially on the approach that the philosopher places between historical and fictional narratives. / Este trabalho tem como objetivo analisar as quatro narrativas longas de Milton Hatoum, partindo da observa??o de tra?os comuns na situa??o familiar dos narradores. A personagem inominada de Relato de um certo Oriente tenta compreender o abandono materno. Em Dois irm?os, Nael descobre que seu pai ? um dos membros da fam?lia na qual ele e a m?e s?o agregados, e o narrador n?o tem d?vidas de que a assun??o da paternidade nunca ser? sequer aventada, pois os dois jamais ser?o aceitos como iguais por essa fam?lia. Em Cinzas do Norte, Lavo perdeu os pais quando ainda era crian?a. Arminto, em ?rf?os do Eldorado, ? ?rf?o de m?e, que morreu durante o parto dele, e o pai n?o hesita em culp?-lo por isso. Todos esses narradores s?o, de alguma forma, abandonados ou ?rf?os. A hip?tese interpretativa ? a de que esse estatuto dos narradores est? intrinsecamente relacionado ? pr?pria atividade de narrar. Isso porque aquele que tem a tarefa de contar uma hist?ria deve lidar com a perda que a passagem do tempo representa, pois o acesso ao passado ? dificultado por diversas situa??es, como, por exemplo, a morte daqueles que testemunharam os fatos que se quer narrar. A aus?ncia do pai, da m?e ou de ambos, que caracteriza os narradores de Hatoum, se coaduna com essa falta, situa??o que condiciona o olhar, sempre melanc?lico, dirigido ao passado. O estado melanc?lico ? superado, entretanto, no pr?prio fazer narrativo, tarefa que exige a organiza??o de relatos fragment?rios, lembran?as dispersas, bem como a reuni?o de documentos e objetos do passado, tudo sendo configurado em uma narrativa. A imagem da melancolia associada ?queles que t?m de escrever ? an?loga ? condi??o do tradutor, conforme Walter Benjamin problematizou em A tarefa do tradutor, texto que aparece como subs?dio interpretativo, assim como o trabalho de Suzana Kampff Lages, Walter Benjamin: tradu??o e melancolia, al?m de Luto e melancolia, de Freud. O car?ter sempre fragment?rio da mem?ria, a degrada??o que a passagem do tempo imp?e a tudo e a todos, caracter?sticas que conferem aos romances de Hatoum o aspecto de verdadeiros invent?rios de ru?nas, ensejou a busca de novo aporte te?rico em Benjamin, dessa vez em Origem do drama tr?gico alem?o, e em alguns de seus comentadores. Em Benjamin ainda se encontrou a supera??o da condi??o melanc?lica atrav?s do trabalho do tradutor/escritor, como acontece aos narradores aos quais este estudo se dedica, mas a an?lise da produ??o romanesca de Milton Hatoum tamb?m oportunizou uma tentativa de interpreta??o das quest?es narratol?gicas aqui levantadas a partir de Tempo e narrativa, de Paul Ricoeur, sobretudo na aproxima??o que o fil?sofo realiza entre narrativas hist?rica e ficcional.

Made available in DSpace on 2015-04-14T13:38:32Z (GMT). No. of bitstreams: 1 436418 - Parcial.pdf: 369872 bytes, checksum: 7abbdae05b7aaa5e127dcb3f421e7370 (MD5) Previous issue date: 2012-01-02 / The study in question plans to discuss the relation between writing a literary text and the teaching of Creative Writing. For that purpose, the idea of some authors and theorists are verified about the subject. Aside from that, it presents briefly the process of creating a fictional novel entitled Amor ? Guilhotina, describing the trajectory out of the literary text since the germ of the literary work until its relation with philosophy. / O presente estudo pretende discutir a rela??o entre a escrita de um texto liter?rio e o ensino da Escrita Criativa. Para tanto, verificam-se as ideias de alguns escritores e te?ricos sobre o assunto. Al?m disso, apresenta de forma breve o processo de cria??o ficcional da novela intitulada Amor ? guilhotina, descrevendo a trajet?ria percorrida fora do texto liter?rio desde o germe Liter?rio da obra at? a sua rela??o com a filosofia.

Thesis deals with relationship between histomorphological and molecular-genetic findings of selected salivary gland tumors. Author, as a molecular-cytogeneticist mainly focused on detection of tumor-specific translocations of the salivary gland tumors which can serve as differential diagnostic markers. The thesis is composed as a commented files of authors own publications, and it is divided into four parts. First part deepens the knowledge of salivary adenoid cystic carcinoma. It was proved, that t(6;9)(q22-23;p23-24) resulting in fusion of transcription factors MYB-NFIB, or more rarely t(8;9) resulting in MYBL1-NFIB fusion represent robust differential diagnostic marker of adenoid cystic carcinoma. Further it was proved, that the 1p36 deletion can serve as an unfavorable prognostic indicator of adenoid cystic carcinoma, as the patients with 1p36 deletion had significantly lower survival. Second part summarizes new developments about mammary analogue secretory carcinoma (MASC), which was described by our group as a new salivary tumor entity characterized by translocation t(12;15)(p13;q25) resulting in ETV6-NTRK3 fusion. Another novel observation is a discovery of ETV6-RET fusion in a subset of MASC cases. Further, the first two MASCs of nasal mucosa origin have been described. Third part consists...

A compreensão dos caminhos de desativação não radiativa em polímeros conjugados é fundamental para o uso desses materiais em dispositivos luminescentes, células fotovoltaicas e sensores. Nesta tese, os processos não radiativos em filmes automontados de polímero luminescente foram investigados via análise da supressão de intensidade de fotoluminescência, utilizando a técnica de fluorescência estacionária, e através da medida do tempo de vida do estado excitado com fluorescência resolvida no tempo em arranjo de contagem de fótons. A camada emissiva constituída por poli(p-fenileno vinileno) (PPV) obtido da conversão térmica do precursor poli(cloreto de xilideno tetraidrotiofeno) (PTHT) apresentou tempos de vida entre 150 e 250 ps, e fraca dependência com o comprimento de onda de detecção da emissão. Na presença de uma monocamada contendo azocorante Vermelho do Congo (CR) ou ftalocianina tetrassulfonada de níquel (NiTsPc) atuando como receptor de energia foi observada supressão da fluorescência e encurtamento do tempo de vida (50-100ps). À medida que se aumenta a distância entre as camadas de doador e receptor via interposição de bicamadas de espaçador, a dinâmica do sistema tende à dinâmica de decaimento do estado excitado do PPV na ausência de receptor. A dependência da eficiência com a distância 1/r2 ou 1/r3 apontam para transferência de energia ressonante (RET) típica da interação plano-plano ou plano-camada. Os processos não radiativos foram também estudados em função da diluição de segmentos PPV dispersos em matriz de polieletrólito poli(cloreto de dodecildimetilamônio) PDAC. A diluição dos segmentos conjugados aumenta a eficiência quântica de emissão, torna o mecanismo de desativação mais lento (500 ps) e diminui a dependência do tempo de vida com o comprimento de onda de detecção, devido à menor eficiência dos mecanismos de desativação não radiativa. Na presença de uma camada receptora, a eficiência de transferência de energia é maior para amostras com segmentos mais diluídos indicando que esse mecanismo compete com os processos internos à própria camada emissiva. O tempo de vida aumenta em filmes com mais baixo grau de conjugação e a dependência com o comprimento de onda de emissão é mais forte. Em resumo, a técnica de automontagem se mostrou adequada para obter filmes com propriedades fotofísicas controláveis no nível molecular, que puderam ser estudadas com espectroscopias de fluorescência. / Understanding the pathway of excitation in conjugated polymers is important for using these materials as active layer in devices, photovoltaic cells and sensors. In this thesis, non-radiative processes in layer-by-layer (LbL) films were investigated with measurements of fluorescence quenching in steady-state fluorescence spectroscopy and of the singlet excited state lifetime using time-resolved fluorescence spectroscopy in a single photon counting (SPC) apparatus. The emissive layer of poly(p-phenylene vinylene) (PPV) obtained via thermal conversion of the soluble precursor poly(xylylidene tetrahydrothiophenium) chloride (PTHT) showed lifetime 150-250 ps and weak dependence on the emission wavelength. In the presence of an acceptor layer of either Congo Red (CR) or nickel tetrasulfonated phthalocyanine (NiTsPc) the PL intensity was quenched and the lifetime was shorter (50 -100 ps). Upon increasing the distance between the energy donor (PPV) and acceptor layers by interposing bilayers of inert polyelectrolytes the dynamics tended to the PPV dynamics. The distance-dependence of the energy transfer efficiency (1/r2 or 1/r3) points to a resonant process (RET) with a plane-to-plane or plane-to-slab interaction. The non-radiative processes were also studied for varying dilutions of the PPV segments in a matrix of the polyelectrolyte poly(dodecyl methylamonium chloride) (PDAC). This dilution increased the quantum efficiency and led to longer lifetimes (500 ps) owing to a less effective non-radiative energy transfer. When an energy acceptor layer is present, energy transfer is more efficient for the most diluted systems, indicating that such transfer competes with internal processes in the emissive layer. The lifetime increased in films with low degree of conjugation, for which there was a stronger dependence on the emission wavelength. It is concluded that the LbL methodology was suitable to obtain photophysical film properties that could be controlled at the molecular level, and investigated with varied fluorescence spectroscopies.

This thesis consists of two parts. The first part deals with the visible emission of ZnO Nanocrystals and its possible application in Resonance Energy Transfer (RET) studies. The second part of the thesis is on the magnetic properties of the layered transition metal Thiophosphates MPS3 (M = Mn, Fe), their solid solutions and intercalation compounds. Recent advances in semiconductor nanocrystals or quantum dots (QDs) as inorganic fluorophores have pioneered a new direction in the fluorescent based techniques to investigate fundamental processes in lifesciences. Their broad absorption spectra with narrow, Size-tunable emissions with high quantum e±ciency and stability under relative harsh environments have made inorganic QD's the fluorophores of choice in many applications. Among inorganic fluorophores the II-VI semiconductors based on cadmium chalcogenides are the front-runners. The cytotoxicity associated with these QDs is, however, a major drawback and has lead to the search for new nanocrystalline fluorophores that are non-toxic and possess the same favorable fluorescence properties as the Cd based QDs, viz, tunability and narrow spectral profile. ZnO Nano particles are known to exhibit two emission bands; a narrow emission band in UV around 380 nm (3.25 eV) at a wavelength just below the onset of the band gap excitation in the absorption spectra and a broad emission band in the blue-green part of the visible spectrum, with a maximum between 500 and 550 nm (2.5-2.2 eV). The UV Emission originates from the recombination of bound excitons - excited electrons in the Conduction band with holes in the valence band. The visible emission of ZnO nanocrystals is known to involve deep trap states that lie approximately midway between the Conduction and valence bands and surface defects that exist as shallow traps. In principle, visible-light-emitting ZnO nanocrystals would be ideal candidates as replacement for Cd-based fluorescent labels since they are nontoxic, less expensive, and chemically stable in air. Nanoscale ZnO, however, tends to aggregate and/or undergo Ostwald ripening be-Cause of high surface free energy resulting in an increase in crystallite size and consequent Disappearance of the visible emission. Most attempts to stabilize the ZnO nanocrystals by Capping has usually resulted in the quenching of the visible trap emission. The objective of the present study was to stabilize the visible light emission of ZnO nanocrystals, to Understand the origin and mechanism of the visible emission and to explore the possibility Of using the visible emission of ZnO in RET studies. The stabilization of visible light emission in ZnO nanocrystals was achieved by forming ZnO:MgO core-shell nanocrystals. The nanocrystals were synthesized by a sequential preparative procedure that involved formation of a ZnO core followed by an MgO shell. The Nanocrystals were characterized by using XRD, TEM, optical absorption and photoluminescence spectroscopy. These are described in Chapter 2 of the thesis. The ZnO: MgO Core-shell nanostructures exhibit stable emission in the visible for extended periods. Application of the ZnO: MgO nanocrystals either as fluorescent probes or RET studies require that they be dispersible in both polar and non-polar solvents. This as realized by appropriate choice of the capping agents (Chapter 3). ZnO: MgO nanocrystals with hydrophobic surface were obtained by capping the nanocrystals with oleic acid. The oleate capped ZnO: MgO nanocrystals are soluble in a variety of non-polar organic solvents with no change in their emission properties. Water-soluble ZnO: MgO nanocrystals were obtained by capping the ZnO:MgO nanocrystals with carboxymethyl-β-cyclodextrin (CMCD). The hydroxyl groups located at the rim of the cyclodextrin cavity renders the surface hydrophilic. The integrity of the CMCD molecules are preserved on capping and their by hydrophobic cavities available for host-guest chemistry. The visible emission of The ZnO: MgO nanocrystals are unaltered by the nature of the capping agent. The origin and mechanism of the visible emission from ZnO: MgO nanocrystals has been Investigated using time-resolved emission spectroscopy technique (Chapter 4). The time-evolution of the photoluminescence spectra show that there are, in fact, two features in the visible emission whose relative importance and efficiencies vary with time. These features originate from recombination involving trapped electrons and holes, respectively, And with efficiencies that depend on the occupancy of the trap density of states. The application of the visible emission of ZnO: MgO nanocrystals as resonance energy transfer (RET) donors in water and hydrophobic media are demonstrated. In aqueous media, the carboxymethyl β-cyclodextrin (CMCD) capped ZnO: MgO nanocrystals is able to accommodate the organic dye Nile Red by an inclusion in the anchored hydrophobic cyclodextrin cavity forming a 1:1 complex. Nile Red was chosen as the guest molecule because its absorption has appreciable overlap with ZnO: MgO visible emission, a prerequisite for RET to occur. The resonance energy transfer on the band gap excitation of The ZnO core to included Red molecules in the CMCD-ZnO: MgO-Nile Red supramolecular assembly is demonstrated in aqueous media. A similar RET process is shown to occur in the non-polar media in the oleate capped ZnO: MgO nanocrystals when Nile Red is partitioned from the solvent into hydrophobic anchored oleate chains. The wavelength dependent energy transfer in the system has been studied using time-resolved emission spectroscopic technique. The importance of trap states in giving rise to non-Forster distance dependence for the RET is highlighted. The second part of the thesis deals with magnetism in low dimensional layered transition metal thiophophates, MPS3 (M = Mn, Fe). Low dimensional magnetic systems continue to be a fertile ground for discovering new phenomena and properties. Among two-dimensional magnetic systems the insulating transition metal thiophosphates are one of the few known layered systems, in which both magnetic and crystallographic lattices are two dimensional (2D). In the metal chalcogenophosphates, the magnetic MPX3 layers are separated by a van der Waals gap that effectively rules out interlayer exchange and hence these systems are nearly perfect 2D magnetic systems, with the magnetic ions forming a honeycomb arrangement within the layer. Due to the crystallographic two-dimensional nature these materials may be intercalated by variety of molecules or ions leading to change in magnetic properties. The objective of this thesis work is to try and modify the magnetic properties of the transition metal thiophosphates either by forming solid solutions of the type, M1-xMxPS3, (M, M = Mn, Fe) or by intercalating hydrated metal ions within the layers. The structure, Bonding, reactivity and magnetic properties are briefly introduced in Chapter 7. The Scope and nature of the present work in presented towards the end of the chapter. MnPS3 and FePS3 have identical crystal structures and both order antiferromagnetically at low temperatures, TN. The in-plane magnetic structures of the antiferromagnetically ordered the Neel state in the two compounds are, however, different. In MnPS3 the spins Alternate up-down whereas in FePS3 the spins are arranged as ferromagnetic chains with Alternate chains coupled antiferromagnetically. Since the crystal structures are identical, These two compounds can form solid solutions, Mn1-xFexPS3(0≤x≥1) over the entire concentration range. The magnetic properties of the single crystals of the solid solutions was measured by using a SQUID magnetometer. This system is of interest since the contrasting Neel states of the end-members may give rise to new magnetic phenomena at intermediate composition. It is shown that the magnetic behavior falls into three distinct categories. The Mn-rich compositions behave like a dilute MnPS3 lattice, the Fe-rich compositions behave like dilute FePS3 and in the intermediate compositions a spin-glass like phase appears. The phase boundaries for these regime in Mn1-xFexPS3, 0≤x≥1 is shown to be related to the percolation threshold for a honeycomb lattice. MnPS3 is known to undergo a unusual ion-exchange intercalation reaction. Intercalation occurs by the inclusion of hydrated metal ions in the galleries of MnPS3 with charge neutrality maintained by loss of the Mn2+ ions from the layer (Equation). MnPS3 + 2xG+ (aq) → Mn1-xPS3 [G (H2O) y] 2x + xMn2+ (aq) Where G is a neutral guest species. This chemistry has been exploited to intercalate hydrated Mn2+ ions in the interlamellar space to give Mn1-xPS3[Mn(H2O)6]x. the magnetic properties of this 3D analogue of MnPS3 has been investigated in Chapter 9.

La progression tumorale repose sur l'acquisition progressive d'anomalies génétiques qui vont conduire à la prolifération dérégulée de ces cellules. Il existe cependant des systèmes de protection contre cette progression tumorale que l'on appelle systèmes de sauvegarde. Ainsi, pour se transformer, la cellule tumorale doit franchir ces barrières anti-tumorales. Les résultats de mon travail de thèse, qui avait pour objectif initial d'identifier les altérations moléculaires précoces de l'oncogenèse, m'ont permis de mettre en évidence un nouveau mécanisme de sauvegarde anti-tumoral. Pour cette étude, un modèle d'étude in vitro de l'initiation et de la progression tumorale déclenchée par l'oncogène RET développé par notre équipe a été utilisé. Grâce à l'utilisation de ce système, nous avons pu montrer que le Réticulum Endoplasmique (RE) est un senseur efficace de l'altération du métabolisme glucidique déclenchée par les signalisations oncogéniques, et que le stress qu'il subit alors, conduit à l'apoptose. Ce travail a permis de mettre mis en évidence que les cellules malignes qui franchissent cette barrière peuvent alors bénéficier d'un effet pro-tumorale du SRE. Ainsi, les résultats présentés dans ce manuscrit offrent une meilleure compréhension du rôle complexe que joue le SRE dans la cancérogénèse / Carcinogenesis involves not only inactivation of tumourigenesis barriers, but also alterations in energy metabolism to fulfil the synthetic and bioenergetic requirements for fast and uncontrolled growth. Our study supports a model in which the ER acts as a node between altered glucose metabolism and tumourigenesis barriers. This major site in the cell for protein folding and maturation, can sense glucose limitation that results from oncogenic-mediated increased glucose demand, and consequently trigger unfolded protein response-dependent apoptosis. As such, the ER functions as a surveillance mechanism that suppresses the emergence of tumour cells. Overcoming this early barrier involves a specific attenuation of the pro-apoptotic PERK-CHOP branch of the unfolded protein response, a cellular adaptation that in turn may favour malignant progression. These observations bring new insights into the complex role of the unfolded protein response during tumourigenesis

Thesis deals with relationship between histomorphological and molecular-genetic findings of selected salivary gland tumors. Author, as a molecular-cytogeneticist mainly focused on detection of tumor-specific translocations of the salivary gland tumors which can serve as differential diagnostic markers. The thesis is composed as a commented files of authors own publications, and it is divided into four parts. First part deepens the knowledge of salivary adenoid cystic carcinoma. It was proved, that t(6;9)(q22-23;p23-24) resulting in fusion of transcription factors MYB-NFIB, or more rarely t(8;9) resulting in MYBL1-NFIB fusion represent robust differential diagnostic marker of adenoid cystic carcinoma. Further it was proved, that the 1p36 deletion can serve as an unfavorable prognostic indicator of adenoid cystic carcinoma, as the patients with 1p36 deletion had significantly lower survival. Second part summarizes new developments about mammary analogue secretory carcinoma (MASC), which was described by our group as a new salivary tumor entity characterized by translocation t(12;15)(p13;q25) resulting in ETV6-NTRK3 fusion. Another novel observation is a discovery of ETV6-RET fusion in a subset of MASC cases. Further, the first two MASCs of nasal mucosa origin have been described. Third part consists...

Introdução: A Neoplasia endócrina múltipla do tipo 2 (NEM-2) é uma síndrome tumoral de herança autossômica dominante, na qual os tumores associados são carcinoma medular de tireoide (CMT), feocromocitoma (FEO) e hiperparatireoidismo primário (HPT). Esta síndrome ocorre devido a mutações ativadoras no proto-oncogene RET que alteram a via do receptor tirosina quinase RET. Essas mutações levam à ativação constitutiva de vias de sinalização desregulando o ciclo celular. Segundo os Consensos Internacionais de 2001 e 2009 sobre CMT/NEM-2, portadores de mutações no gene RET, inclusive indivíduos assintomáticos, devem ser submetidos a tireoidectomia total (TT) preventiva, aumentando a chance de cura da doença. Não é recomendado rastreamento clínico em portadores que apresentem somente polimorfismos isolados (variante não patogênica). No entanto, existem indivíduos que carregam variantes genéticas de significado clínico desconhecido (VUS), gerando dúvida quanto à conduta clínica. Atualmente, não se tem conhecimento se essas variantes podem ou não estar envolvidas no aumento do risco ao desenvolvimento de CMT. Dessa forma, o presente projeto analisou diversos aspectos como frequência alélica, estudo in silico, dados na literatura e nos bancos genéticos com o intuito de abranger o entendimento dessas variantes e auxiliar na indicação de conduta clínica adequada aos portadores de RET VUS. Objetivo: Expandir o conhecimento do potencial patogênico das VUS do gene RET, focando na classificação controversa da variante p.Y791F. Métodos: Foi realizado o rastreamento dos exons hotspots do gene RET em indivíduos adultos/idosos-controle e em pacientes com CMT através da técnica de Sequenciamento de Nova Geração (NGS) e Sequenciamento de Sanger. Foi também analisada a predição computacional da patogenicidade dessas variantes em seis diferentes programas preditivos. Foi feito o levantamento de dados em diversos bancos genéticos. Resultados: As variantes p.Y791N, p.Y791F e p.E511K foram encontradas no rastreamento genético das amostras-controle sequenciadas. Além dessas variantes, foram identificadas e estudadas famílias de pacientes com CMT portadoras das variantes p.V648I e p.K666N. A variante p.Y791F foi identificada em um novo caso somente com FEO. A análise in silico demonstrou que 4/6 programas foram mais informativos, e que 25/48 VUS demonstram alterar a estrutura físico-química da proteína RET. A frequência alélica encontrada nos bancos de dados de indivíduos-controle e indivíduos com tumores foram bastante baixas. Apenas 15/48 VUS possuem dados sobre estudos in vitro. Conclusão: Nossos dados sugerem que a variante RET p.Y791F, quando isolada e sem coocorrência com mutações conhecidas RET, se comporta como um polimorfismo benigno raro, sem associação do aumento do risco ao CMT. Já a associação de p.Y791F com mutações conhecidas RET, como a C634Y, pode levar ao desenvolvimento de fenótipos atípicos, como maior risco ao feocromocitoma. A variante p.V648I é provavelmente um polimorfismo benigno raro, evidenciado pelo seguimento clínico de aproximadamente 15 anos de uma família portadora dessa variante, sem evidências de CMT, FEO ou HPT. Há necessidade de mais dados para classificar apropriadamente as demais VUS; no entanto, devido a possibilidade das variantes p.E511K, K666N e Y791N poderem ser patogênicas, portadores devem ser monitorados clinicamente / Introduction: Multiple endocrine neoplasia type 2 (MEN-2) is a tumor syndrome with autosomal dominant inheritance, in which tumors are associated with medullary thyroid carcinoma (MTC), pheochromocytoma (FEO) and primary hyperparathyroidism (HPT). This syndrome occurs due to activating mutations in the RET proto-oncogene, which lead to constitutive activation of tyrosine kinase signaling pathways that deregulate the cell cycle. According to the International Consensus on MTC/MEN-2 of 2001 and 2009 one should recommend that RET mutation carriers, including asymptomatic individuals, should undergo prophylactic total thyroidectomy (TT), increasing the chance of cure of the disease. It is not recommended clinical screening in patients that show only isolated polymorphisms (non-pathogenic variant). However, there are individuals who carry genetic variants of unknown clinical significance (VUS), generating doubt about the best clinical management. Currently, there is no consistent knowledge whether these variants may or may not be involved with the increased risk to MTC. The present project has approached the several aspects of these VUS, such as the allele frequency, in silico pathogenic prediction, published data and public databases, in order to increase our knowledge about VUS, in an attempt to contribute by offering appropriate clinical management to VUS carriers. Objective: To expand the knowledge of the pathogenic potential of some of the VUS of the RET gene, focusing especially on the controversial genetic variant p.Y791F. Methods: We performed the mutation screening of hotspots exons of the RET gene of DNA samples of 2061 adult/elderly healthy individuals and of patients with CMT by Sanger sequencing and Next Generation Sequencing (NGS) techniques. Pathogenic predictions of the studied variants were generated using six genetic softwares. Allelic frequency of RET VUS was assessed in different public databanks. Results: Genetic screening of control samples identified the presence of p.Y791N, p.Y791F and p.E511K germline variants. Patients with MTC carrying p.V648I and p.K666N germline variants were localized and family members were screened and clinically investigated. In addition, a new case with pheochromocytoma was found to carry the p.Y791F germline variant. The in silico analyses showed that 4 out of 6 packages were more informative, suggesting physico-chemical structure alteration caused by 25 out of 48 RET VUS. Very low allele frequencies were found in the public databases including healthy individuals and tumor samples. In vitro studies have been performed only for 15 out of 48 RET VUS. Conclusion: Our data strongly suggest that the p.Y791F variant, when occurring in an isolated form, is a benign polymorphism not associated with increased risk of MTC. Conversely, its co-occurrence with bona fide RET mutations as C634Y may lead to modulation of the phenotype, as increasing the frequencies of large and bilateral pheochromocytomas in MEN2A families. Family members carrying the p.V648I variant isolate have been followed clinically for approximately 15 years. As no indication of MCT, pheochromocytoma or hyperparathyroidism development has been documented, we conclude that this variant is a rare RET benign polymorphism. More information is needed to a better characterization of other VUS as E511K, K666N and Y791N. Thus, carriers with these variants should be necessarily examined through a periodic clinical follow up