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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Que lugar é esse, União VI? O pertencer às favelas de Londrina-PR / What place is this, Union VI? The belong to shanty town of Londrina PR

Okamura, Júlia Luciana Pereira das Dores 16 September 2016 (has links)
É expressiva no espaço urbano brasileiro a presença de um grande número de moradores vivendo em situação de risco e vulnerabilidade social. Isso é visível diante da precariedade de suas moradias, da infraestrutura dos bairros, da condição socioeconômica entre outros fatores, chamando a atenção para a rapidez com que essas moradias favelas - se proliferaram na cidade de Londrina. Diante deste contexto, esta tese tem como objetivo desenvolver um estudo centrado nas reflexões sobre o pertencimento ao lugar favela por parte dos moradores do Jardim União da Vitória VI, localizado na zona sul da cidade de Londrina, bem como analisar a temática sobre o termo lugar e do conceito de favela. Além disso, averiguar sua percepção por um grupo de pessoas, e alunos do 7ºano de duas escolas públicas localizadas na área de estudo ou próxima, e as intervenções do poder público local na elaboração e implantação de politicas públicas, levando em conta a questão habitacional e o contexto histórico da formação da cidade de Londrina. / It is expressive in the Brazilian urban area the presence of a great number of dweller living in a risk situation and social vulnerability. It is visible before preciosity of their dwellings, the districts infrastructure, social-economic condition among other factors, calling the attention to rapidity with which theses dwellings shanty town, proliferate in Londrina city. Ahead this context, this thesis has as objective develops a center study in the reflection about the belonging to the shanty town place by its dwellers of Victory Union Garden VI, situated in the South Zone of Londrina city, as well as to analyze the theme about place term and the concept of shanty town. Beyond that, ascertain its perception by a group of people, and pupils of 7º year of two public schools situated in the study area or close to it, and the local Public Authority interventions in elaboration and implementation of public politics, taking in account the housing issue and the historical context of the formation of Londrina city.
62

Design and Optimization of Recombinant Antibodies Directed Against Platelet Glycoprotein VI with Therapeutic and Diagnostic Potentials / Conception et optimisation d'anticorps recombinants à potentiel thérapeutique et diagnostique, dirigés contre la Glycoprotéine VI (GPVI) plaquettaire

Zahid, Muhammad 24 November 2011 (has links)
La glycoprotéine VI (GP VI) des plaquettes sanguines humaines est le récepteur principal du collagène, composé le plus thrombogénique d'une paroi vasculaire lésée. Ainsi, GPVI est souvent considérée comme une cible de premier plan pour développer des tests diagnostiques ou des stratégies thérapeutiques innovantes, efficaces et sûres afin d'améliorer encore la prise en charge des accidents ischémiques. Les anticorps monoclonaux et leurs fragments actifs produits par ingénierie moléculaire constituent aujourd'hui une nouvelle classe de biomolécules en plein essor avec des propriétés bien adaptées à des applications thérapeutiques et diagnostiques. Notre groupe a produit plusieurs anticorps monoclonaux anti-GPVI par immunisation génique de souris. Ces anticorps ont une affinité élevé pour leur cible. Ils de distinguent les uns des autres par leur spécificité épitopique ainsi que par les effets engendrés par leur liaison à GPVI. Parmi ces anticorps, l'un présente un fort potentiel diagnostique parce qu'il reconnait les formes mono- et dimériques de GPVI, mais sa liaison aux plaquettes peut induire une activation ou la perte de GPVI. Un autre anticorps présente un fort potentiel thérapeutique parce que ses fragments actifs monovalents obtenus par papaïnolyse neutralisent l'interaction entre les plaquettes et le collagène, sans activer les plaquette. Cependant, l'origine xénogénique de cet anticorps est responsable d'une forte immunogénicité qui en interdit des applications en médecine humaine. Dans cette étude, nous avons conçus un fragments variable d'anticorps simple chaine (scFv) utile pour quantifier l'expression de la GPVI à la surface des plaquettes sanguines. Ce scFv a été reformaté de façon à lui insérer un motif de reconnaissance de la Protéine L (PpL) qui facilite sa détection et sa purification sans avoir recours à un peptide "drapeau". Nous avons également humanisé et créé plusieurs fragments d'anticorps recombinants monovalents inhibiteurs de l'interaction GPVI / collagène. Ces fragments d'anticorps présentent un potentiel thérapeutique élevé. / Human platelets glycoprotein VI (GPVI) is evidenced to be a platelet receptor of major importance in the occurrence of arterial thrombosis. Thus, it can be considered to be of great interest in diagnosis and therapeutic of atheriosclerotic diseases. Antibodies are powerful molecules which can be used in both diagnostic as well as for therapeutic purposes due to their unique characteristics. Monoclonal and recombinant antibodies have antigen restricted specificity, high affinity and can be used in various assays. Moreover, the good knowledge of their structure and molecular engineering facilities now allows the antibody modulation according to desired properties.Our group has already produced several monoclonal antibodies to human GPVI by gene gun immunization against the immunoadhesin hGPVI-Fc, which differ in fine epitopespecificity, affinity and other functional properties (Lecut et al. 2003). One, 3J24, with diagnostic potential while the other, 9O12, has a therapeutic potential because it blocks the binding of GPVI to collagen. Its Fab fragment has been extensively characterized in vitro,ex vivo and in vivo for its antithrombotic properties.Here, we designed and reshaped a single-chain antibody fragment (scFv) based on 3J24variable domains for the quantification of GPVI with diagnostic potential. We were also involved in the design, production and functional evaluation of humanized anti-GPVI recombinant antibody fragments (scFvs and Fabs) with therapeutic properties.
63

Monolithic Heterovalent Integration of Compound Semiconductors and Their Applications

January 2019 (has links)
abstract: Compound semiconductors tend to be more ionic if the cations and anions are further apart in atomic columns, such as II-VI compared to III-V compounds, due in part to the greater electronegativity difference between group-II and group-VI atoms. As the electronegativity between the atoms increases, the materials tend to have more insulator-like properties, including higher energy band gaps and lower indices of refraction. This enables significant differences in the optical and electronic properties between III-V, II-VI, and IV-VI semiconductors. Many of these binary compounds have similar lattice constants and therefore can be grown epitaxially on top of each other to create monolithic heterovalent and heterocrystalline heterostructures with optical and electronic properties unachievable in conventional isovalent heterostructures. Due to the difference in vapor pressures and ideal growth temperatures between the different materials, precise growth methods are required to optimize the structural and optical properties of the heterovalent heterostructures. The high growth temperatures of the III-V materials can damage the II-VI barrier layers, and therefore a compromise must be found for the growth of high-quality III-V and II-VI layers in the same heterostructure. In addition, precise control of the interface termination has been shown to play a significant role in the crystal quality of the different layers in the structure. For non-polar orientations, elemental fluxes of group-II and group-V atoms consistently help to lower the stacking fault and dislocation density in the II-VI/III-V heterovalent heterostructures. This dissertation examines the epitaxial growth of heterovalent and heterocrystalline heterostructures lattice-matched to GaAs, GaSb, and InSb substrates in a single-chamber growth system. The optimal growth conditions to achieve alternating layers of III-V, II-VI, and IV-VI semiconductors have been investigated using temperature ramps, migration-enhanced epitaxy, and elemental fluxes at the interface. GaSb/ZnTe distributed Bragg reflectors grown in this study significantly outperform similar isovalent GaSb-based reflectors and show great promise for mid-infrared applications. Also, carrier confinement in GaAs/ZnSe quantum wells was achieved with a low-temperature growth technique for GaAs on ZnSe. Additionally, nearly lattice-matched heterocrystalline PbTe/CdTe/InSb heterostructures with strong infrared photoluminescence were demonstrated, along with virtual (211) CdZnTe/InSb substrates with extremely low defect densities for long-wavelength optoelectronic applications. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
64

The sorption of uranium(VI) and neptunium(V) onto surfaces of selected metal oxides and alumosilicates studied by in situ vibrational spectroscopy

Müller, K. 22 September 2010 (has links) (PDF)
The migration behavior of actinides and other radioactive contaminants in the environment is controlled by prominent molecular phenomena such as hydrolysis and complexation reactions in aqueous solutions as well as the diffusion and sorption onto minerals present along groundwater flow paths. These reactions significantly influence the mobility and bioavailability of the metal ions in the environment, in particular at liquid-solid interfaces. Hence, for the assessment of migration processes the knowledge of the mechanisms occurring at interfaces is crucial. The required structural information can be obtained using various spectroscopic techniques. In the present study, the speciation of uranium(VI) and neptunium(V) at environmentally relevant mineral – water interfaces of oxides of titania, alumina, silica, zinc, and alumosilicates has been investigated by the application of attenuated total reflection Fouriertransform infrared (ATR FT-IR) spectroscopy. Moreover, the distribution of the hydrolysis products in micromolar aqueous solutions of U(VI) and Np(V/VI) at ambient atmosphere has been characterized for the first time, by a combination of ATR FT-IR spectroscopy, near infrared (NIR) absorption spectroscopy, and speciation modeling applying updated thermodynamic databases. From the infrared spectra, a significant change of the U(VI) speciation is derived upon lowering the U(VI) concentration from the milli- to the micromolar range, strongly suggesting the dominance of monomeric U(VI) hydrolysis products in the micromolar solutions. In contradiction to the predicted speciation, monomeric hydroxo species are already present at pH ≥ 2.5 and become dominant at pH 3. At higher pH levels (> 6), a complex speciation is evidenced including carbonate containing complexes. For the first time, spectroscopic results of Np(VI) hydrolysis reactions are provided in the submillimolar concentration range and at pH values up to 5.3, and they are comparatively discussed with U(VI). For both actinides, the formation of similar species is suggested at pH ≤ 4, whereas at higher pH, the infrared spectra evidence structurally different species. At pH 5, the formation of a carbonate-containing dimeric complex, that is (NpO2)2CO3(OH)3^-, is strongly suggested, whereas carbonate complexation occurs only under more alkaline conditions in the U(VI) system. The results from the experiments of the sorption processes clearly demonstrate the formation of stable U(VI) surface complexes at all investigated mineral phases. This includes several metal oxides, namely TiO2, Al2O3, and SiO2, serving as model systems for the elucidation of more complex mineral systems, and several alumosilicates, such as kaolinite, muscovite and biotite. From a multiplicity of in situ experiments, the impact of sorbent characteristics and variations in the aqueous U(VI) system on the sorption processes was considered. A preferential formation of an inner-sphere complex is derived from the spectra of the TiO2 and SiO2 phases. In addition, since the in situ FT-IR experiments provide an online monitoring of the absorption changes of the sorption processes, the course of the formation of the U(VI) surface complexes can be observed spectroscopically. It is shown that after prolonged sorption time on TiO2, resulting in a highly covered surface, outer-sphere complexation predominates the sorption processes. The prevailing crystallographic modification, namely anatase and rutile, does not significantly contribute to the spectra, whereas surface specific parameters, e.g. surface area or porosity are important. A significant different surface complexation is observed for Al2O3. The formation of innerspheric species is assumed at low U(VI) surface coverage which is fostered at low pH, high ionic strength and short contact times. At proceeded sorption the surface complexation changes. From the spectra, an outer-spheric coordination followed by surface precipitation or polymerization is deduced. Moreover, in contrast to TiO2, the appearance of ternary U(VI) carbonate complexes on the γ-Al2O3 surface is suggested. The first results of the surface reactions on more complex, naturally occurring minerals (kaolinite, muscovite and biotite) show the formation of U(VI) inner-sphere sorption complexes. These findings are supported by the spectral information of the metal oxide surfaces. In this work, first spectroscopic results from sorption of aqueous Np(V) on solid mineral phases are provided. It is shown that stable inner-sphere surface species of NpO2 ^+ are formed on TiO2. Outer-sphere complexation is found to play a minor role due to the pH independence of the sorption species throughout the pH range 4 – 7.6. The comparative spectroscopic experiments of Np(V) sorption onto TiO2, SiO2, and ZnO indicate structurally similar bidentate surface complexes. The multiplicity of IR spectroscopic experiments carried out within this study yields a profound collection of spectroscopic data which will be used as references for future investigations of more complex sorption systems in aqueous solution. Furthermore, from a methodological point of view, this study comprehensively extends the application of ATR FT-IR spectroscopic experiments to a wide range in the field of radioecology. The results obtained in this work contribute to a better understanding of the geochemical interactions of actinides, in particular U(VI) and Np(V/VI), in the environment. Consequently, more reliable predictions of actinides migration which are essential for the safety assessment of nuclear waste repositories can be performed.
65

Intervention divine et violence sacrée dans les Gesta Dei per Francos de Guibert de Nogent et la Vita Ludovici Grossi regis de Suger

Thériault, Gabriel January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
66

The reign of Leo VI (886-912) : personal relationships and political ideologies

Tougher, Shaun F. January 1994 (has links)
Leo VI (886-912) is an emperor who has suffered from a hostile and inadequate press. He has been portrayed as a weak and careless emperor, known mainly for his dubious parentage and marital exploits. This thesis questions these popular perceptions of Leo, and attempts to present a more realistic account of the emperor and the politics of his age. The aspects of the reign tackled focus on essential elements of Leo's life and rule, presented in a rough chronological framework, and the themes of personal relationships and political ideologies are recurrent. Chapter One examines Leo's relationship with Basil I and his attitude to his Macedonian heritage. Chapter Two considers the fate of the monumental figure of Photios at the emperor's hands. Chapter Three deals with the position and role of the 'all powerful' Stylianos Zaoutzes during the first half of the reign. Chapter Four ponders the origin and meaning of Leo's 'wise' epithet. Chapter Five focuses on the emperor's four marriages. Chapter Six turns to the course of foreign affairs during the reign, concentrating on Bulgaria and the Arab navy, and considers the emperor's attitude towards these military problems. Chapter Seven examines the emperor's relationship with his senatorial officials, focusing on two distinct groups, eunuchs and the generals who originated from families of the eastern frontier. Finally Chapter Eight addresses the tense relationship that existed between Leo and his brother and co-emperor Alexander. What emerges from a consideration of these aspects of Leo and his reign is that this is an emperor who does not deserve the popular perceptions that still persist about him. He was an emperor who forged a 'new' and distinctive imperial style, a style that should not deceive us; he may have been literate, sedentary and city-based, but he was also forceful, strong-willed and conscientious.
67

Correlação entre os achados da fibronasolaringoscopia e da polissonografia em pacientes com mucopolissacaridose Tipo VI

Pereira, Denise Rotta Ruttkay January 2015 (has links)
INTRODUÇÃO: As mucopolissacaridoses (MPSs) formam um grupo raro de doenças congênitas lisossômicas de depósito, relacionadas a desordens do metabolismo dos glicosaminoglicanos (GAG). Os GAG, parcialmente degradados, acumulam-se nos diversos tecidos do organismo, principalmente das vias aéreas superiores, levando a apneia obstrutiva do sono nesses pacientes. OBJETIVO: Descrever os achados em vias aéreas de pacientes com mucopolissacaridose tipo VI, identificados pela fibronasolaringoscopia (FNL), e compará-los com as alterações na polissonografia (PSG). DELINEAMENTO: Estudo transversal. MÉTODOS: Incluíram-se todos os pacientes com MPS tipo VI, com idade entre 14 e 24 anos, que fazem acompanhamento no Serviço de Genética do Hospital de Clínicas de Porto Alegre. Coletaram-se informações clinico-epidemiológicas dos pais ou responsáveis por meio de entrevista. Realizou-se PSG de noite inteira, classificada em normal, leve, moderada ou gravemente alterada. FNL foi efetuada em consultório, sem sedação, entre 7 dias antes e 7 dias após a PSG. As fibronasolaringoscopias foram gravadas em DVD e analisadas com cegamento para os achados na PSG. A FNL foi classificada em 1- sem obstrução, 2- obstrução leve, 3 - obstrução moderada ou 4 - obstrução grave de vias aéreas, de acordo com o maior escore obtido nas diferentes regiões. RESULTADOS: Avaliaram-se 11 pacientes com MPS tipo VI, sendo 7 (63,6%) do sexo masculino. Na FNL, oito (72,7%) apresentaram obstrução grave, dois (18,2%) obstrução moderada e um (9,1%), obstrução leve de vias aéreas. Na PSG, nove pacientes (81,8%) apresentaram síndrome da apneia obstrutiva do sono (SAOS). Destes, cinco (45,5%) apresentaram SAOS leve, três (27,2%) SAOS moderada e um (9,1%) SAOS grave. Encontrou-se hipertrofia moderada a grave das conchas nasais em 81,8% dos sujeitos e 64% apresentaram obstrução grave em região supraglótica. Não houve associação entre os achados da FNL e da PSG (p=0,454; kappa = - 0,09; IC 95%: - 0,34 a 0,17), demonstrando que não há concordância entre os métodos de avaliação. CONCLUSÃO: A apneia apresenta alta prevalência na amostra e não se correlaciona com o grau de obstrução da via aérea superior. / INTRODUCTION: Mucopolysaccharidosis (MPS) is a lysosomal storage disease that affects an enzyme responsible for the degradation of glycosaminoglycans (GAGs). Partially degraded GAGs accumulate in several tissues, such as the upper airways, which leads to the development of obstructive sleep apnea (OSA) in these patients. OBJECTIVE: To describe airway findings in mucopolysaccharidosis type VI patients, identified with flexible fiberoptic laryngoscopy (FFL), and compare it with polysomnography (PSG) abnormalities. STUDY DESIGN: Cross-sectional study. METHODS: All MPS VI diagnosed patients, age ranging from 14 to 24 years, followed at the Genetic Division of Hospital de Clinicas de Porto Alegre were included. Clinical and epidemiological data were obtained by an interview with parents. Overnight PSG was performed, and results were classified as normal or mildly, moderately or severely abnormal. FFL was performed at the outpatient clinics, without sedation, between 7 days prior and seven days after PSG. Flexible fiberoptic laryngoscopies were recorded in DVD and analyzed by a blind researcher. FFL was classified as 1 - no obstruction, 2 - mild obstruction, 3 - moderate obstruction or 4 - severe obstruction of the airways, using the highest score obtained in all the regions. RESULTS: Eleven patients with MPS VI were included, and seven (63.6%) were males. Eight (72.7%) had severe obstruction of the airways, two (18.2%) had moderate obstruction, and one (9.1%) had mild obstruction at FFL. At PSG, nine (81.8%) patients had obstructive sleep apnea syndrome (OSAS). Of these, five (45.5%) were mild, three (27.2%) moderate, and one (9.1%) severe OSAS. Moderate to severe hypertrophy of the nasal turbinates was found in 81.8% of the patients, and 64% had severe infiltration of the supraglotic area. There was no association between FFL and PSG findings (p=0.454; kappa= -0.09; CI= -0.34 to 0.17), demonstrating no agreement between the two methods. CONCLUSIONS: In the present study, all patients with MPS showed some degree of airway obstruction. As there was no correlation between FFL and PSG findings, we suggest performing PSG in all subjects with MPS in order to determine disease severity.
68

Domus regis: a Casa Real portuguesa no Rio de Janeiro (1808-1821) / Domus regis: the portuguese Royal Household in Rio de Janeiro (1808-1821)

Santiago Silva de Andrade 14 April 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Instituição fundamental à monarquia lusitana, a Casa Real portuguesa abrangia, em seu espaço, centenas de criados, homens e mulheres das mais diversas origens. Com a transferência da Corte para o Rio de Janeiro, em 1808, o príncipe regente d. João reestruturou o seu universo doméstico, estabelecendo aqui, e à semelhança de Portugal, todos os departamentos imperativos à correta execução das tarefas cotidianas da sua Casa: cavalariça, cozinha, serviço de copa, câmara, aquisição de gêneros alimentícios, etc. Esta tese tem como objeto a conformação da Casa Real portuguesa no Rio de Janeiro, entre os anos de 1808 e 1821. Serão analisados aqui a estrutura organizacional da Casa Real; os conflitos suscitados entre os recém-emigrados agentes do espaço doméstico régio e os súditos fluminenses; os mecanismos de remuneração peculiares ao universo doméstico joanino; as formas de acesso à Casa Real; e, finalmente, a estrutura financeira da Casa Real portuguesa. Num quadro mais amplo, procurou-se relacionar a Casa do Rei aos outros poderes instituídos na cidade, agora Corte, do Rio de Janeiro, de forma a demonstrar que o espaço doméstico da monarquia era, também, uma instituição relevante na montagem da administração joanina na América e, conseqüentemente, na transformação de um espaço historicamente colonial em centro do império português. / Lusitanian monarchy's fundamental institution, the portuguese Royal Household covered in it's space hundreds of servants, men and women from different social backgrounds. After the transfer of the portuguese court to Rio de Janeiro, prince regent d. João restructured his domestic universe, setting here, the same way as in Portugal, all the required departments for the correct execution of everyday tasks of his House: stable, kitchen, pantry service, câmara, purchase of food articles, etc. This thesis intends to analyze the conformation of the portuguese Royal Household in Rio de Janeiro, between the years of 1808 and 1821. Will be analyzed here the Royal Household's organizacional structure; the disputes among the recent immigrants domestic servants and the Rio de Janeiro's inhabitants; the peculiar paying mechanisms of the royal domestic world; the forms of access to the Royal Household; and the financial structure of the portuguese Royal Household. Within a broader framework, we tried to relate the King's House to the others established powers on the court of Rio de Janeiro, in order to demonstrate that the monarchy's domestic space was also a relevant institution on the assembling of the royal administration in America and, consequently, on the transformation of an historically colonial area in the center of the portuguese empire.
69

Complexation of actinides Am(III), Th(IV), Pu(IV) and U(VI) with poly-N-dentate ligands SO3-Ph-BTP and SO3-Ph-BTBP / Complexation des actinides Am(III), Th(IV), Pu(IV) et U(VI) par les ligands polyazotés SO3PhBTP et SO3PhBTBP

Steczek, Lukasz 12 December 2016 (has links)
La complexation des ions Th(IV), U(VI), Am(III) et Pu(IV) avec le ligand hydrophile SO3-Ph-BTP4- et des ions Th(IV) et Pu(IV) avec le ligand hydrophile SO3-Ph-BTBP4– a été étudiée. Ces nouveaux ligands ont été proposés dans le cadre du recyclage des combustibles nucléaires usés, pour la séparation sélective d’actinides(III) par rapport aux lanthanides(III) et aux produits de fission. L’objectif de ce travail était d’étudier la capacité de ces ligands à complexer les actinides de degré supérieur, soit IV et VI. Après des essais infructueux par spectroscopie directe, la méthode appliquée pour atteindre cet objectif est une étude par extraction liquide-liquide. Le système d'extraction est composé de deux ligands chélatants qui sont en compétition pour complexer les ions actinides: l’extractant tétraoctyldiglycolamide (TODGA), molécule neutre, lipophile, donneur oxygéné tridenté et le complexant anionique hydrophile tridenté (ou tétradenté) SO3-Ph-BT(B)P4–. La méthode consiste à mesurer l’évolution de l’extraction du cation par le TODGA (DM) lors de l’ajout de quantité croissante de complexant en phase aqueuse, tout en fixant une force ionique constante en phase aqueuse. Un modèle mathématique est établi en prenant en compte les équilibres d’extraction et de complexation, il permet d’évaluer la stœchiométrie des complexes formés et leurs constantes de stabilité relatives. Les expériences réalisées ont permis de conclure à la présence des complexes An:SO3-Ph-BTP4– 1:1 et 1:2 pour tous les actinides testés et du complexe 1:1 pour An(IV):SO3-Ph-BTBP4–.Deux séries de constantes conditionnelles de stabilité de ces complexes ont été déterminées dans nos expériences: des constantes de stabilité conditionnelles, αL,i, valables pour une solution 1 M en nitrate et faciles à évaluer et des constantes ßL,i, considérant de manière explicite la complexation des cations par les nitrates, toujours pour une force ionique I = 1 M. En considérant les constantes conditionnelles de stabilité ßL,i, des actinides pour les ligands SO3-Ph-BTP4- et SO3-Ph-BTBP4-, l'ordre suivant est observé: UO22+ < Am3+ < Th4+ < Pu(IV), conformément à l’augmentation du potentiel ionique z/r2, où z est la charge formelle et r est le rayon de l'ion métallique. L'analyse des valeurs ßL,i suggère que les effets électrostatiques jouent un rôle plus important dans la formation des complexes entre les ligands azotés polydentés et les ions actinide.Pour les complexes de Am3+ avec le ligand SO3-Ph-BTP4– tridenté, si on compare nos résultats avec l’étude menée par TRLFS (fluorescence laser à résolution temporelle) pour des complexes analogues de Cm3+, les constantes de stabilité de stoechiométrie 1:1 et 1:2, déterminées par extraction liquide-liquide sont plus faibles. En outre, la stœchiométrie 1:3 décrite pour Cm3+ n'a pas été détectée dans notre étude. Les constantes de stabilité des complexes SO3-Ph-BTP et SO3-Ph-BTBP avec les actinides(IV) n'ont pas été rapportées dans la littérature. Néanmoins les complexes supérieurs n’ont pas été observés: 1:3 avec le ligand tridenté SO3-Ph-BTP4– et 1:2 avec le ligand tétradenté SO3-Ph-BTBP4–. Ces observations surprenantes à priori peuvent provenir du traitement mathématique simplifié des équilibres chimiques et nécessiteraient des vérifications supplémentaires par des techniques permettant d’identifier les complexes en solution. Cependant, les données de partage obtenues ont permis de proposer des constantes de stabilité conditionnelles qui peuvent être exploitées pour modéliser le comportement des actinides (III), (IV) et (VI) dans un procédé de séparation. / The complexation of Th(IV), U(VI), Pu(IV) and Am(III) with the hydrophilic ligand SO3-Ph-BTP4–, and of Th(IV) and Pu(IV) with the hydrophilic SO3-Ph-BTBP4– ligand was studied. These new hydrophilic aromatic poly-N-dentate ligands are proposed, in the frame of recycling spent nuclear fuel, for a selective separation of actinides(III) from lanthanides(III) and from other fission products. The aim of this work was to compare the ability of the actinide ions to coordinate these N-dentate molecules. After some disappointing tests with classical spectroscopies, the method of liquid-liquid (solvent) extraction was applied to reach this goal. The extraction system consisted of two chelating ligands that competed for the actinide ions: a lipophilic tri-O-dentate neutral molecule of dioctylamide (TODGA) and a hydrophilic tri(or tetra)-N-dentate anion SO3-Ph-BT(B)P4–. The simple model we applied, well known in literature, considered chemical equilibria resulting in accumulation of the metal complexes with the lipophilic ligand in the organic phase, and those with the hydrophilic ligand – in the aqueous phase. With increasing concentration of the hydrophilic ligand (the concentration of the lipophilic ligand being constant) the equilibrium shifted towards the complexes with the hydrophilic ligand, and the distribution ratio of the metal decreased.The results have been interpreted in terms of the formation of 1:1 and 1:2 actinide complexes with tridentate SO3-Ph-BTP4– and only single 1:1 An(IV) complexes with tetradentate SO3-Ph-BTBP4– ligands in the two-phase systems studied. Two series of conditional stability constants of the complexes have been determined in our experiments: one set of the conditional stability constants, αL,i, related to 1 M nitrate media, whereas the other, βL,i, – to aqueous solutions of ionic strength I = 1 M, where the complexation by nitrates was taken into account. In the latter case, when the effect of the actinide complexation by nitrates was deducted, the conditional stability constants, βL,1, of the actinide complexes with SO3-Ph-BTP4– increase in the order UO22+ < Am3+ < Th4+ < Pu(IV), in accordance with the increasing z/r2 ratio (where z is the formal charge and r is the radius of the metal ion). The analysis of the βL,i values suggests that the electrostatic effects play the major role in the formation of the complexes between the poly-N-dentate ligands and actinides ions.Concerning the complexation of Am3+ with the tri-N-dentate SO3-Ph-BTP4– ligand, if we compare our results with the literature values for the analogous Cm3+ complexes studied by a spectroscopic (TRLFS) technique, the stability constants of 1:1 and 1:2 complexes of Am3+ are much lower, and its 1:3 complex has not been found by the solvent extraction method. The stability constants of the SO3-Ph-BTP and SO3-Ph-BTBP complexes with the actinides(IV) have not been reported yet in literature, therefore such comparison was impossible in this case. However, the expected 1:3 complexes of Pu(IV) and Th(IV) with the SO3-Ph-BTP4– ligand have not been found in our solvent extraction experiments as well. Similarly, only 1:1 Pu and Th complexes with the tetra-N-dentate SO3-Ph-BTBP4– ligand have been found by solvent extraction, in spite of that the 1:2 complexes were also expected. These surprising results could be a result of oversimplification of the used model of extraction, and should be completed by further spectroscopic studies to identify all the complexes formed in the two-phase system studied. Nevertheless, the stability constants determined in the solvent extraction experiments (“practical” stability constants) allow us to correctly describe and to predict the behaviour of metal ions in such two-phase systems.
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Avaliação da concentração da enzima anidrase carbônica VI e sua relação com cárie dentária em crianças obesas / Evaluation of the concentration of the carbonic anydrase VI and its relation with dental caries in obese children

Ana Célia Panveloski Costa 14 August 2015 (has links)
A obesidade e a cárie dentária são problemas de saúde pública, que atingem a população infantil. O objetivo deste estudo foi identificar a prevalência de cárie dentária e relacioná-la com a concentração da enzima anidrase carbônica VI, do íon cálcio, fluxo salivar e quantidade de biofilme dentário em crianças com sobrepeso/obesidade. Foram avaliadas 112 crianças de 4 a 6 anos de idade, de ambos os gêneros. A análise antropométrica foi realizada (percentil do IMC) e através dessa análise as crianças foram divididas em dois grupos: G1 sobrepesos/obesos (n=41) e G2 normais (n=71). Os exames bucais realizados para a cárie dentária foram os índices ceo-s e ICDAS II, quantidade de biofilme dentário pelo Índice de Placa de Turesky e volume de fluxo salivar estimulado. A concentração do íon Cálcio na saliva foi analisada pelo kit colorimétrico e da enzima Anidrase Carbônica VI pelo kit ELISA. Na sequência, as crianças de cada grupo foram divididas em 3 subgrupos: LC (livres de cárie), LI (com lesões iniciais) e C (com cárie). Os testes Wilcoxon, Mann-Whitney, teste t e correlação de Spearman foram aplicados (p<0,05). Não houve diferença significativa no ceo-s entre os grupos. Houve maior concentração média de cálcio salivar no G1 (G1=2847,96mM; G2=1230,90mM;p=0,001) e maior concentração da Anidrase Carbônica VI no G2 (G1=3455,18 pg/mL; G2=442428,9pg/mL;p=0,000). No G1 houve correlação negativa entre o ceo-s e íon Cálcio (r=-0,444;p=0,010). Já no G2, houve correlação negativa entre placa e a Anidrase Carbônica VI (r=-0,551;p=0,014). Pode-se concluir que o íon cálcio é fator protetor para cárie dentária em crianças. Já a anidrase carbônica VI parece não ser biomarcador para a cárie dentária. / Obesity and dental caries are public health problems that affect the child population. The aim of this study was to identify the prevalence of dental caries and relate it to the concentration of the enzyme carbonic anhydrase VI, calcium ion, salivary flow, and dental plaque in overweight/obesity children. The study was conducted on 112 children aged 4-6, of both genders. Anthropometric analysis was performed (BMI percentile) and by this analysis the children were divided into two groups: G1 - overweight/obese (n=41) and G2 - normal (n=71). The oral examinations performed for dental caries were the dmfs and ICDAS II indexes, measurement of the amount of dental plaque by the Turesky Board Index and volume of stimulated salivary flow. The concentration of calcium ion in saliva was measured by a colorimetric kit and the enzyme carbonic anhydrase VI by an ELISA kit. Then, children from each group were divided into three subgroups: CF (caries-free), IL (initial lesions) and D (decayed teeth). The Wilcoxon test, Mann-Whitney, t test and Spearman correlation (p<0.05) were applied. There was no significant difference in the dmfs between groups. There was higher concentration of salivary calcium in G1 (G1=2847.96mM; G2=1230.90mM; p=0.001), and higher concentration of carbonic anhydrase VI in G2 (G1 = 3455.18 pg/ml; G2 = 442428.9pg/ml; p = 0.000). In G1, there was negative correlation between dmfs and salivary calcium (r = -0.444; p = 0.010). In G2, there was negative correlation between dental plaque and carbonic anhydrase VI (r=-0.551; p=0.014). It can be concluded that the calcium ion is a protective factor for dental caries in children. The carbonic anhydrase VI does not seem to be a biomaker of dental caries.

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