The objective was to determine if a correlation exists between Streptococcus mutans and DMFT in the oral cavity. This study examined the feasibility of microbial screenings as an additional caries predictor tool. The sample included 108 participants (ages 18-25) in low, moderate, and high socioeconomic groups. Subjects were selected from one dental clinic and one college in Virginia. Subjects were assessed for DMFT, salivary and plaque bacterial load, and CRA. Salivary load positively correlated with the DMFT. Plaque bacterial load and CRA negatively correlated with DMFT. Comparison of salivary bacterial load among economic levels showed higher bacterial loads with lower economic level only. Twice the observed values were found in the low socioeconomic level with CRA. DMFT and economic level showed differences between economic levels. Microbial screenings may be a useful, additional tool in determining caries risk in oral hygiene programs for all income populations.

In this thesis, Density Functional Theory (DFT) and Dynamical Mean-Field Theory (DMFT) approaches are applied to study the magnetic properties of transition metal nanosystems of different sizes and compositions. In particular, in order to take into account dynamical electron correlation effects (time-resolved local charge interactions), we have adopted the DFT+DMFT formalism and made it suitable for application to nanostructures. Preliminary application of this DFT+DMFT approach, using available codes, to study the magnetic properties of small (2 to 5-atom) Fe and FePt clusters provide meaningful results: dynamical effects lead to a reduction of the cluster magnetic moment as compared to that obtained from DFT or DFT+U (U being the Coulomb repulsion parameter). We have subsequently developed our own nanoDFT+DMFT code and applied it to examine the magnetization of iron particles containing10-147 atoms. Our results for the cluster magnetic moments are in a good agreement with experimental data. In particular, we are able to reproduce the oscillations in magnetic moment with size as observed in the experiments. Also, DFT+DMFT does not lead to an overestimation of magnetization for the clusters in the size range of 10-27 atoms found with DFT and DFT+U. On application of the nanoDFT+DMFT approach to systems with mixed geometry – Fe2O3 film, which are periodic (infinitely extended), in two directions, and finite in the third. Similar to DFT+U, we find that the surface atom magnetic moments are smaller compared to the bulk. However, the absolute values of the surface atoms magnetic moments are smaller in DFT+DMFT. In parallel, we have carried out a systematic study of magnetic anisotropy in bimetallic L10 FePt nanoparticles (20-484 atoms) by using two DFT-based approaches: direct and the torque method. We find that the magnetocrystalline anisotropy (MCA) of FePt clusters is larger than that of the pure Fe and Pt ones. We explain this effect by a large hybridization of 3d Fe- and 5d Pt-atom orbitals, which lead to enhancement of the magnetic moment of the Pt atom, and hence to a larger magnetic anisotropy because of large spin-orbit coupling of Pt atoms. In addition, we find that particles whose (large) central layer consists of Pt atoms, rather than Fe, have larger MCA due to stronger hybridization effects. Such 'protected' MCA, which does not require protective cladding, can be used in modern magnetic technologies.

Syfte: Syftet med denna studie är att framställa och identifiera om det finns en mer avgörande faktor för DMFT-index bland de undersökta biologiska och socioekonomiska faktorerna. Material och metod: En kvalitativ dokumentanalys har utförts med narrativ beskrivning av de undersökta faktorernas betydelse för 12-åriga barns DMFT-index i ett urval av länder över tid. Country Area Profile Project har använts för insamling av DMFT-index samt sockerkonsumtion. De biologiska faktorer som studeras är sockerkonsumtion och vattenfluoridering. De socioekonomiska faktorerna är samhällsomvälvningar, betydelsen av moderns utbildning, tandvårdssystem samt ekonomi. Resultat: Trots ökad sockerkonsumtion i sex av de åtta studerade länder har DMFT-index sänkts över tid. De länder som har fluoriderat sitt dricksvatten uppvisade inte en större sänkning i DMFT-index än de länder som inte använder sig utav vattenfluoridering. Samhällsomvälvningar har påverkat DMFT-index med både sänkningar och höjningar. Mödrar med lägre utbildningsnivå, färre tandvårdsbesök och sämre egenvård ökade risken för ett högre DMFT hos deras barn. Sex av de åtta undersökta länderna har gratis tandvård för barn, men ett minskande DMFT-index kunde studeras i samtliga undersökta länder. Ett högt BNP per capita eller låg ginikoeffiecient innebär inte nödvändigtvis ett lägre DMFT-index. Slutsats: Minskningen av DMFT-index är ett resultat av samtliga undersökta faktorer, biologiska och socioekonomiska. Därför är ingen av de undersökta faktorerna av större betydelse för DMFT och bör respekteras till samma grad i det fortsatta kariespreventiva arbetet. Nyckelord: 12-åringar, biologiska faktorer, CAPP, DMFT-index, socioekonomiska faktorer. / Aim: The purpose of this study is to present and identify a more decisive factor for the DMFT-index among the examined biological and socio-economic factors. Methods: A qualitative document analysis has been carried out with a narrative review of the importance of biological and socio-economic factors for 12-year-old children’s DMFT-index in a selection of countries over time. The Country Area Profile Project has been used for the collection of DMFT-index and sugar consumption. The studied biological factors are sugar consumption and water fluoridation. The socio-economic factors are social unrest, the importance of the mother’s education, dental care and economics. Results: Despite increased sugar consumption in six of the eight countries studied, the DMFT-index has been reduced over time. The countries that have fluoridated their drinking water did not show a larger reduction in the DMFT-index compared to those countries that do not use waterfluoridation. Social unrest has affected the DMFT-index in both directions. Mothers with lower levels of education, rarer dental visits and poorer self-care increased the risk of a higher DMFT in their children. Six of the eight countries studied offer free dental care for children, but a diminishing DMFT-index could still be observed in the other countries. A high GDP per capita or low ginicoefficient does not necessairily result in a lower DMFT-index. Conclusion: The decrease in DMFT-index is a result of all factors studied, biological and socio-economical. Therefore, none of the factors are of greater importance for DMFT and should be respected equally in future caries-preventive work. Key words: 12-year-olds, biological factors, CAPP, DMFT-index, socio-economic factors.

La transition de phase isostructurale du cérium a été et reste l'objet de nombreuses études pour tester les méthodes permettant de décrire les matériaux fortement corrélés.La Théorie du Champ Moyen Dynamique (DMFT) jointe à la Théorie de la fonctionnelle de la densité à permis de décrire de tels systèmes.Pourtant, le calcul des propriétés de l'état fondamental nécessite une très bonne précision de calcul à la fois de la part de la DFT et de la DMFT.Nous utilisons un résolveur Monte Carlo Quantique en Temps Continu (CT-QMC), rapide et capable de simuler les basses températures, combiné à une implantation ondes planes augmentées par projection de la DMFT pour calculer les énergies internes et libres -- et par conséquent l'entropie -- au cours de la transition de phase du cérium.D'importants calculs, utilisant cette implantation, nous ont permis de reconsidérer les propriétés de l'état fondamental et une grande partie de la thermodynamique de la transition de phase α<->γ du cérium à basses températures.En particulier, le bruit stochastique est suffisamment faible pour interpréter, sans ambiguïté, les courbes énergie en fonction du volume.Sur ces dernières, un double point d'inflexion est clairement visible pour l'énergie interne jusqu'à une température relativement basse.Les courbes d'énergie libre mettent, de plus, en évidence l'importance de l'entropie pour ce système.D'autre part, les spectres de photoemission tout au long de la transition de phase sont analysés.Le schéma DMFT est comparé avec des calculs DFT récents et des données expérimentales récentes.Enfin, nous mettons en avant les approximations utilisées et nous nous interrogeons sur leurs validité. / The isostructural phase transition of cerium has been and remains the aim of many studies in order to test methods developed to describe strongly correlated materials.The Dynamical Mean Field Theory (DMFT) combined with density functional theory (DFT) has been successful to describe such systems.However, the computation of the ground state properties requires a very good accuracy from both DFT and DMFT sides.We use thus a strong coupling Continuous Time Quantum Monte Carlo (CT-QMC) solver, which is fast and able to reach low temperatures, in combination with a projector augmented wave (PAW) DMFT implementation to calculate internls and free energies -- and thus the entropy -- during the phase transition of cerium.Extensive calculations using this implementation allows us to carefully reassess the ground state properties and almost all thermodynamics of the α<->γ phase transition in cerium at low temperatures.In particular, stochastic noise is small enough to avoid any ambiguity on the interpretation of energy versus volume curves.On those curves, a double inflexion point is clearly observable ont the internal energy curves untill a relatively low temperature.Moreover, free energy curves highlight the importance of including the entropy contribution.The DMFT picture is put in perspective with recent DFT calculations and recent experimental investigations.Furthermore, photoemission spectra are analysed while the phase transition.Finaly, we discuss the approximations used and raise curiosity about their consideration.

Orientador: Eduardo Miranda / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-23T18:51:04Z (GMT). No. of bitstreams: 1 SuarezVillagran_MarthaYolima_D.pdf: 7321255 bytes, checksum: d76479a0e0c1143207cb4ee380a8034d (MD5) Previous issue date: 2013 / Resumo: Estudamos nesta tese alguns aspectos da transição metal-isolante de Mott no caso desordenado. O modelo no qual baseamos nosso estudo é o modelo de Hubbard desordenado, que é o modelo mais simples a apresentar a transição metal-isolante de Mott. Analisamos esse modelo através da Teoria Dinâmica de Campo Médio Estatística (StatDMFT). Essa teoria é uma extensão natural da Teoria Dinâmica de Campo Médio (DMFT), que foi usada com relativo sucesso nos últimos anos para analisar a transição de Mott no caso limpo. Como no caso dessa última, a StatDMFT incorpora os efeitos de correlação eletrônica apenas nos seus aspetos locais. A desordem é tratada de maneira a incorporar todos os efeitos de localização de Anderson. Com essa técnica, analisamos a transição de Mott desordenada no caso bi-dimensional, usando o Monte Carlo quântico para resolver os problemas de impureza única de Anderson requeridos pela StatDMFT. Encontramos as linhas espinodais nas quais o metal e o isolante deixam de ser meta-estáveis. Também estudamos os padrões espaciais das flutuações de quantidades locais, como a auto-energia e a função de Green local, e mostramos como há o aparecimento de regiões metálicas dentro do isolante e viceversa. Analisamos efeitos de tamanho finito e mostramos que, em consonância com os teoremas de Imry e Ma, a transição de primeira ordem desaparece no limite termodinâmico. Analisamos as propriedades de transporte desse sistema através de um mapeamento a um sistema de resistores aleatórios clássicos e calculamos a corrente média e sua distribuição através da transição metal-isolante. Finalmente, estudamos o comportamento da parede de domínio que se forma entre o isolante e o metal no caso limpo. Isso foi feito através de um modelo de uma cadeia unidimensional conectada a reservatórios, um metálico e um isolante, cada um em uma de suas extremidades. Nesse caso, utilizamos o método da Teoria de Perturbação Iterada para a solução dos modelos de impureza única. Encontramos o comportamento da parede como função da temperatura e das interações / Abstract: In this thesis, we studied some aspects of the Mott metal-insulator transition in the disordered case. The model on which we based our analysis is the disordered Hubbard model, which is the simplest model capable of capturing the Mott metal-insulator transition. We investigated this model through the Statistical Dynamical Mean-Field Theory (statDMFT). This theory is a natural extension of the Dynamical Mean-Field Theory (DMFT), which has been used with relative success in the last several years with the purpose of describing the Mott transition in the clean case. As is the case for the latter theory, the statDMFT incorporates the electronic correlation effects only incorporate Anderson localization effects.. With this technique, we analyzed the disordered two-dimensional Mott transition, using Quantum Monte Carlo to solve the associated single-impurity problems. We found the spinodal lines at which metal and insulator cease to be meta-stable. We also studied the spatial fluctuations of local quantities, such as the self-energy and the local Green¿s function, and showed the appearance of metallic regions within the insulator and vice-versa. We carried out an analysis of finite-size effects and showed that, in agreement with the theorems of Imry and Ma, the first-order transition is smeared in the thermodynamic limit. We analyzed transport properties by means of a mapping to a random classical resistor network and calculated both the average current and its distribution across the metalinsulator transition. Finally, we studied the behavior of the domain wall which forms between the metal and the insulator in the clean case. This was done by means of a model of a one-dimensional chain connected to two reservoirs, one metallic and the other insulating, each attached to one of the chain¿s ends. In this case, we used the Iterated Perturbation Theory technique in order to solve the associated singleimpurity problems. We then established the behavior of the domain wall width as a function of temperature and interactions / Doutorado / Física / Doutora em Ciências

Made available in DSpace on 2014-08-20T14:30:14Z (GMT). No. of bitstreams: 1 Dissertacao_Eduarda_Rodrigues_Dutra.pdf: 1414666 bytes, checksum: ec6fdd591603266bfd4c19955d49f0b0 (MD5) Previous issue date: 2012-05-10 / The aim of this study was to test the accuracy of three partial protocols of oral examination, assessing only first molars, to estimate dental caries prevalence, severity and its association with risk factors. A representative sample of 1,211 children with 8-12 years of age from 20 public and private schools from urban area of Pelotas, Brazil was assessed. DMFT index was obtained by full mouth examination and three partial protocols: P1 all first molars; P2 e P3 first molars from two random diagonal quadrants (1 and 3, 2 and 4). Socioeconomic, behavioral and oral health variables were also collected. Sensitivity, absolute and relative bias and inflation factor were calculated for each partial protocol using dental caries prevalence (DMFT ≥ 1).Risk factors were assessed for all protocols using Poisson Regression for both dental caries prevalence and severity (mean DMFT). Prevalence of dental caries was 32.4% for full mouth examination, 30.2% for P1, 22.2% for P2 and 21.4% for P3. In comparison with full-mouth examination, P1 showed a higher sensitivity [93.1% (CI 95% 91.5; 94.5)]. All protocols showed similar magnitude of association measures for all risk factors investigated, using caries prevalence and mean DMFT. The partial protocols showed potential applicability in epidemiological studies assessing dental caries prevalence and associated factors in schoolchildren aging 8-12 years / O estudo teve como objetivo testar a acurácia de três protocolos de exame parcial da cavidade bucal, avaliando somente primeiros molares, para estimativa da prevalência e severidade de cárie, assim como da sua associação com variáveis socioeconômicas, comportamentais e de saúde bucal em escolares com faixa etária entre 8 e 12 anos. Uma amostra representativa de 1211 escolares, proveniente de 20 escolas (públicas e privadas) de Pelotas-RS, foi avaliada. Através de exame bucal da boca inteira, foi obtido o índice CPOD (número de dentes cariados, perdidos e obturados). A partir deste exame, estimou-se o índice CPOD para outros três protocolos parciais de exame avaliando somente os primeiros molares: P1 avaliação dos quatro elementos e; P2 e P3 avaliação de dois molares de quadrantes contralaterais.Variáveis socioeconômicas, comportamentais e de saúde bucal foram também coletadas. Utilizando a prevalência de cárie (CPOD ≥ 1) foram calculadas a sensibilidade, viés absoluto, viés relativo e fator de inflação para cada um dos protocolos parciais em relação ao exame de boca inteira. A associação entre a prevalência e a média do CPOD com as variáveis independentes também foi avaliada para os diferentes protocolos, utilizando Regressão de Poisson. A prevalência de cárie foi de 32,4% para o exame de boca inteira, 30,2% para P1, 22,2% para P2 e 21,4% pra P3. O P1, comparado à avaliação de boca inteira, mostrou alta sensibilidade [93,1% (IC 95% 91,5; 94,5)]. Utilizando a prevalência de cárie dentária e o CPOD médio, foi possível constatar a similaridade dos quatro protocolos quanto a magnitude de associação dos fatores de risco investigados.Os protocolos parciais estudados demonstram potencial da aplicabilidade em levantamentos epidemiológicos que avaliem a prevalência da cárie dentária e a sua associação com fatores demográficos e sócio comportamentais em crianças entre 8 e 12 anos

The transition-metal oxides (TMOs) are a material class host to a number of intriguing and potentially technologically useful phenomena as a result of many-body correlation effects, from superconductivity, magnetic and orbital ordering, to ferroelectricity and metal-insulator transitions. Here, materials with similar structures and seemingly equivalent electronic configuration often exhibit wildly different properties as a result of strong competition between different ground states from the many degrees of freedom, whose balance can be further tuned through the use of pressure, doping, magnetic fields or temperature. To investigate these materials, we make use of photoelectron spectroscopy (PES), probing elementary excitations possible in the material and thus providing linked information both about the ground state and possible excited states, closely related to the physical properties of a material such as its response to external fields. Angle-resolved PES (ARPES) provides additional momentum information and as a result, it is uniquely suited to investigate the character of the electronic structure of solids as it resolves the dispersion, meaningful in the independent-electron view where crystal momentum is a well-defined quantum number, but which can retain validity even in strongly correlated systems through the concept of quasiparticles. While ARPES is a well-established technique, it is rarely used in the soft X-ray regime (SX-ARPES) due to significant experimental challenges posed. However, the higher energies in SX-ARPES allow it to be significantly more bulk-sensitive, an extremely important fact since the properties of the bulk material and its surface are often extremely, or worse, subtly different. Critically, this permits measurements on single crystals of TMOs, whose surfaces may show roughness or reconstruction, for example as a result of a polar surface compensation, but whose bulk properties are well-defined in contrast to thin films which are additionally subject to substrate effects. We demonstrate on three rather different perovskite oxides, a three-dimensional class of TMOs, that is worthwhile to overcome these issues since it provides access to the true momentum-resolved bulk electronic properties of materials and allows filling noticeable gaps in literature of k-resolved electronic structure measurements for this class of compounds stemming from the impossibility of such measurements at lower energy. A commonality between the materials studied in this thesis is the absence of a strong electronic symmetry-breaking order, such as local-moment antiferromagnetism or charge ordering, that could suppress the existence of sufficiently long-lived quasiparticles to observe dispersion (or equivalently prevent a mobile photo-hole). We first establish that SX-ARPES is indeed capable and suited to measure the bulk-representative electronic structure by measurements on the perfect cubic d1 perovskite ReO3. We present the first k-resolved electronic structure for this material which is rather well explained by band structure, especially close to the Fermi level. In particular, we show and quantify the impact of the significant spin-orbit coupling on the Fermi surface and bands. However, the oxygen bands are less well reproduced by calculations and are correctable by use of hybrid functionals, taken as a sign of spurious self-interaction effects - likely due to the large extent and density differences between delocalised Re 5d and more localised O 2p. We also show that there are signs of some hitherto unknown distortion in ReO3. We then turn to LaNiO3, a metallic oxide in a family of formally d7 rare-earth nickelates which otherwise all undergo metal-insulator and antiferromagnetic (AFM) transitions as well as oxygen bond disproportionation, with a strong competition between these ground states and possible exotic resulting states in the phase diagram. We are able to resolve the dispersion of the eg quasiparticle spectrum along high symmetry cuts of this material as well as its Fermi surface, the latter of which is accurately reproduced by band theory calculations. We investigate the influence of the rhombohedral distortion present in the material through unfolding methods to better compare their influence to measurement, and show how significantly it affects the dispersion, confirming again the importance of single crystals. Its effects are shown to be similar to correlation-induced mass enhancement and their effects are untangled with the help of first DFT+U and later rhombohedral multi-band dynamical mean-field theory (DMFT) calculations. Local correlation effects prove to be the dominant influence on the spectrum, although certain k-dependent mismatches remain, pointing to a possible simultaneous importance of non-local mechanisms. Finally, on the d6 system LaCoO3 that is close to a spin-state transition, we show that this method can also be applied to insulating oxides. Absent a Fermi surface, we naturally concentrate more on the full valence band, where we show that the observed dispersion is well-described by mean-field band methods in the low-spin (LS) regime of LaCoO3 provided that static energy corrections of DFT+U are accounted for (which show a good match to local LS many-body configuration interaction calculations), thus providing k-resolved evidence that one may effectively consider LS LaCoO3 a band insulator, despite possibly strong correlations. We further unveil clear evidence of crystal periodicity doubling by observation of a backfolded oxygen band, and show evidence of a significant asymmetry in the k-resolved lineshape in the valence band and lastly we take a look at the spin state of Co at the surface, which, contrary to prior results, appears to be the same as in the bulk, but which we show to be complicated by significant orbital-shape matrix element effects.

Introdução - O envelhecimento da população tem implicações significativas para a organização da atenção odontológica. Objetivo - Este estudo teve por objetivo avaliar as condições de saúde bucal de idosos moradores na área urbana do município de São Paulo em 2006. Método - O Estudo SABE (Saúde Bem Estar e Envelhecimento) é um estudo multicêntrico envolvendo sete países da América Latina e Caribe cuja primeira fase teve início em 2000 e em 2006 transformou-se em um estudo longitudinal. Em 2006, foram examinadas 1.212 pessoas de 65 anos de idade e mais que representaram 515.040 idosos residentes na área urbana do município de São Paulo. Os exames foram realizados por 15 cirurgiões-dentistas calibrados segundo os critérios metodológicos recomendados pela Organização Mundial da Saúde. Resultados - A média do Índice CPOD (número de dentes cariados, perdidos e restaurados) nas mulheres foi de 29,87 e entre os homens de 27,42. A freqüência do CPOD variou de 7 a 32 nas mulheres e de 8 a 32 nos homens. Não houve idosos com todos os dentes presentes. A necessidade de tratamento mais prevalente foi de exodontia. Em relação à condição periodontal, nas mulheres, 90,84% dos sextantes superiores e 84,56% dos sextantes inferiores eram edêntulos e, nos homens, 82,11% e 74,96, respectivamente. Perda de inserção periodontal de 0 a 3 mm foi a alteração periodontal mais freqüente em ambos os sexos. A prevalência do edentulismo total foi de 69,40% nas mulheres e 30,60% nos homens; 74,48% das mulheres e 53,43% dos homens faziam uso de prótese total superior e 45,51% das mulheres e 33,77% dos homens faziam uso de prótese total inferior. Uso de prótese total superior e inferior teve prevalência de 44,40% em mulheres e 32,90% em homens. O uso de prótese parcial removível foi mais comum no arco dentário inferior em mulheres (16,38%). Necessitavam de prótese total, mas não a usavam 5,70% da população, sendo que a porcentagem foi maior na população masculina (14,78%). A necessidade de prótese total teve maior prevalência seguida da necessidade de prótese parcial removível. Dentre os idosos que usam outros tipos de prótese a média de dentes presentes foi de 11,62 nas mulheres e 13,84 nos homens. No que diz respeito a presença de lesão em tecidos moles da cavidade bucal, 18,93% da mulheres e 15,95% dos homens, apresentaram algum tipo de lesão. Conclusão - As mulheres apresentaram índice CPOD maior que os homens. Com exceção do número de dentes cariados que foi maior entre a população masculina, os demais componentes tiveram maior prevalência entre a população feminina. Quanto à condição periodontal, a maior prevalência de sextantes nulos ocorreu entre as mulheres. Também o número de mulheres edêntulas foi maior que o número de homens nessa condição, assim como o uso de próteses foi mais prevalente entre elas. A presença de lesões nos tecidos moles da boca foi mais prevalente na população feminina. Pode-se concluir que as mulheres tiveram mais acesso aos serviços odontológicos e que os homens apresentaram grandes necessidades de tratamento acumuladas. Pela medida de mutilação apresentada pelas mulheres e pelas grandes necessidades acumuladas entre os homens, pode-se concluir que se deve buscar uma nova abordagem no cuidado em saúde bucal para o idoso. / Introduction - The aging of the population has material effects on the dental assistance organization. Purpose - The purpose of this study was to evaluate the clinical conditions of dental health among the elderly population living in the city of São Paulo in 2006. Methodology - The SABE Study - Health, Welfare and Aging is a multicenter study made in seven countries of Latin America and Caribbean region. The first phase of this study began in 2000, having become a longitudinal study in 2006, year at which 1,212 people of 65 years old or more were examined, representing 515.040 elderly resident in the metropolitan area of São Paulo. 15 dental surgeons conducted the exams according to the methodological criteria established by the Wealth World Organization. Results - DMFT (number of lost or restored teeth or teeth with caries) rate average was 29.87 in the female population and 27.42 in the male population. The DMFT frequency had a variation from 7 to 32 in the female population and 8 to 32 in the male population. There were no elderly elements with all their permanent teeth. The more prevailing treatment was extraction. Among the female population 90.84% have no upper high sextant and 84.56% have no anterior sextant. Among the male population 82.11% and 74.96%, respectively, have no sextants. Attachment losses from 0 to 3 mm were more frequent in both male and female population. The prevalence of total edentulism was 69.40% in the female population and 30.60% in the male population; 74.48% of women and 53.43% of men have total superior prostheses implanted and 45.51% of women and 33.77% of men have total inferior prostheses implanted. The use of total superior and inferior prosthesis prevailed among 44.40% in the female population and 32.90% in the male population; on the other hand, the removable partial prosthesis was more common in the inferior arcade of the female population (16.38%). The average of population in the need but without a total prosthesis was 5.70%, and the largest percentage was found among the male population (14.78%). The necessity of total prosthesis was more prevailing, followed by removable partial prosthesis. Among the elderly population that has other prosthesis types implanted, the average of present teeth was 11.62 in the female population and 13.84 in the male population. As to the presence of injury in soft tissues in the oral cavity, 18.93% in the female population and 15.95% in the male population have any kind of injury. Conclusion - The female population had a higher DMFT ratio than the male population. Except the number of teeth with caries, which was higher among the male population, the other elements showed a higher prevalence among the female population. As to the periodontal condition, the higher prevalence of sextants inexistency was found, as well as the edentulous women, and the use o prosthesis. The presence of injury in the oral soft tissues was more prevailing among the female population. It is possible to conclude that the female population had more access to dental services and the male population has more accrued necessities. By the scope of the mutilation showed by women and accrued necessities found among the male population it is possible to conclude that a new approach should be use to address dental treatment in the elderly population.

Introdução - O envelhecimento da população tem implicações significativas para a organização da atenção odontológica. Objetivo - Este estudo teve por objetivo avaliar as condições de saúde bucal de idosos moradores na área urbana do município de São Paulo em 2006. Método - O Estudo SABE (Saúde Bem Estar e Envelhecimento) é um estudo multicêntrico envolvendo sete países da América Latina e Caribe cuja primeira fase teve início em 2000 e em 2006 transformou-se em um estudo longitudinal. Em 2006, foram examinadas 1.212 pessoas de 65 anos de idade e mais que representaram 515.040 idosos residentes na área urbana do município de São Paulo. Os exames foram realizados por 15 cirurgiões-dentistas calibrados segundo os critérios metodológicos recomendados pela Organização Mundial da Saúde. Resultados - A média do Índice CPOD (número de dentes cariados, perdidos e restaurados) nas mulheres foi de 29,87 e entre os homens de 27,42. A freqüência do CPOD variou de 7 a 32 nas mulheres e de 8 a 32 nos homens. Não houve idosos com todos os dentes presentes. A necessidade de tratamento mais prevalente foi de exodontia. Em relação à condição periodontal, nas mulheres, 90,84% dos sextantes superiores e 84,56% dos sextantes inferiores eram edêntulos e, nos homens, 82,11% e 74,96, respectivamente. Perda de inserção periodontal de 0 a 3 mm foi a alteração periodontal mais freqüente em ambos os sexos. A prevalência do edentulismo total foi de 69,40% nas mulheres e 30,60% nos homens; 74,48% das mulheres e 53,43% dos homens faziam uso de prótese total superior e 45,51% das mulheres e 33,77% dos homens faziam uso de prótese total inferior. Uso de prótese total superior e inferior teve prevalência de 44,40% em mulheres e 32,90% em homens. O uso de prótese parcial removível foi mais comum no arco dentário inferior em mulheres (16,38%). Necessitavam de prótese total, mas não a usavam 5,70% da população, sendo que a porcentagem foi maior na população masculina (14,78%). A necessidade de prótese total teve maior prevalência seguida da necessidade de prótese parcial removível. Dentre os idosos que usam outros tipos de prótese a média de dentes presentes foi de 11,62 nas mulheres e 13,84 nos homens. No que diz respeito a presença de lesão em tecidos moles da cavidade bucal, 18,93% da mulheres e 15,95% dos homens, apresentaram algum tipo de lesão. Conclusão - As mulheres apresentaram índice CPOD maior que os homens. Com exceção do número de dentes cariados que foi maior entre a população masculina, os demais componentes tiveram maior prevalência entre a população feminina. Quanto à condição periodontal, a maior prevalência de sextantes nulos ocorreu entre as mulheres. Também o número de mulheres edêntulas foi maior que o número de homens nessa condição, assim como o uso de próteses foi mais prevalente entre elas. A presença de lesões nos tecidos moles da boca foi mais prevalente na população feminina. Pode-se concluir que as mulheres tiveram mais acesso aos serviços odontológicos e que os homens apresentaram grandes necessidades de tratamento acumuladas. Pela medida de mutilação apresentada pelas mulheres e pelas grandes necessidades acumuladas entre os homens, pode-se concluir que se deve buscar uma nova abordagem no cuidado em saúde bucal para o idoso. / Introduction - The aging of the population has material effects on the dental assistance organization. Purpose - The purpose of this study was to evaluate the clinical conditions of dental health among the elderly population living in the city of São Paulo in 2006. Methodology - The SABE Study - Health, Welfare and Aging is a multicenter study made in seven countries of Latin America and Caribbean region. The first phase of this study began in 2000, having become a longitudinal study in 2006, year at which 1,212 people of 65 years old or more were examined, representing 515.040 elderly resident in the metropolitan area of São Paulo. 15 dental surgeons conducted the exams according to the methodological criteria established by the Wealth World Organization. Results - DMFT (number of lost or restored teeth or teeth with caries) rate average was 29.87 in the female population and 27.42 in the male population. The DMFT frequency had a variation from 7 to 32 in the female population and 8 to 32 in the male population. There were no elderly elements with all their permanent teeth. The more prevailing treatment was extraction. Among the female population 90.84% have no upper high sextant and 84.56% have no anterior sextant. Among the male population 82.11% and 74.96%, respectively, have no sextants. Attachment losses from 0 to 3 mm were more frequent in both male and female population. The prevalence of total edentulism was 69.40% in the female population and 30.60% in the male population; 74.48% of women and 53.43% of men have total superior prostheses implanted and 45.51% of women and 33.77% of men have total inferior prostheses implanted. The use of total superior and inferior prosthesis prevailed among 44.40% in the female population and 32.90% in the male population; on the other hand, the removable partial prosthesis was more common in the inferior arcade of the female population (16.38%). The average of population in the need but without a total prosthesis was 5.70%, and the largest percentage was found among the male population (14.78%). The necessity of total prosthesis was more prevailing, followed by removable partial prosthesis. Among the elderly population that has other prosthesis types implanted, the average of present teeth was 11.62 in the female population and 13.84 in the male population. As to the presence of injury in soft tissues in the oral cavity, 18.93% in the female population and 15.95% in the male population have any kind of injury. Conclusion - The female population had a higher DMFT ratio than the male population. Except the number of teeth with caries, which was higher among the male population, the other elements showed a higher prevalence among the female population. As to the periodontal condition, the higher prevalence of sextants inexistency was found, as well as the edentulous women, and the use o prosthesis. The presence of injury in the oral soft tissues was more prevailing among the female population. It is possible to conclude that the female population had more access to dental services and the male population has more accrued necessities. By the scope of the mutilation showed by women and accrued necessities found among the male population it is possible to conclude that a new approach should be use to address dental treatment in the elderly population.

L'étude et la connaissance des propriétés électroniques des matériaux ne constituent pas seulement un enjeu technologique : il s'agit aussi d'un problème fondamental. Au delà des isolants et des métaux usuels, il existe des systèmes plus complexes dans lesquels même l'approximation du liquide de Fermi, pourtant fructueuse dans de nombreux cas, est mise en défaut par les fortes interactions.<br /><br />Le cas des premiers oxydes de métaux de transition, pour lesquels les orbitales de valence sont des orbitales 3d, est particulièrement intéressant. Le nombre quantique principal n = 3 est le plus faible autorisé pour la valeur l = 2 du nombre quantique angulaire : ainsi, étant déjà orthogonales aux autres orbitales par leur partie angulaire, les orbitales 3d n'ont pas besoin de noeuds dans leur partie radiale et sont donc assez localisées autour du noyau. La formation de bandes de conduction est possible (malgré le faible recouvrement direct entre orbitales 3d), mais en même temps les porteurs de charge sont soumis à de fortes interactions locales. A cause de ces corrélations, certains oxydes de métaux de transition (comme LaTiO3) sont isolants bien que leur bande 3d ne soit que partiellement remplie et qu'on attendrait donc une conductivité métallique. La localisation électronique peut aussi mener à la formation de moments magnétiques locaux, et l'interaction de ces derniers avec les porteurs de charge mobiles confère aux<br />Manganates leur propriété de magnéto-résistance géante. Enfin, on ne peut ne pas mentionner la célèbre famille des Cuprates CuO, pour lesquelles une supraconductivité haute Tc a été découverte en 1986.<br /><br />Parmi les oxydes de métaux de transition, les Cobaltates dopées au sodium NaxCoO2 suscitent elles aussi un grand intérêt. Leur fort pouvoir thermoélectrique associé à une faible résistivité suggère de possibles applications en réfrigération. Leur diagramme des phases fait apparaître la coexistence d'électrons de conduction et de moments magnétiques localisés, ainsi qu'une phase supraconductrice (ce sont donc les seuls oxydes de transition 3d supraconducteurs, avec les Cuprates et les Titanates). Comme dans les Cuprates, leur structure cristallographique est lamellaire et quasi-bidimensionnelle, mais contrairement à ces dernières où les Cu forment un réseau carré, les Co sont agencés en un réseau triangulaire susceptible de frustrer des interactions magnétiques. Malgré les nombreux travaux qui ont été consacrés à ces composés, la description de base de leur structure de bandes est sujette à controverse et les calculs “premiers principes” demeurent en désaccord avec les expériences de photoémission.<br /><br />Le travail présenté ici vise à obtenir un modèle effectif capable de prédire les bonnes excitations de basse énergie des Cobaltates de sodium. Après un chapitre d'introduction générale sur ces composés, j'exposerai les limites des calculs théoriques déjà effectués puis je décrirai la dérivation de notre modèle effectif avant de présenter les résultats obtenus. Des annexes seront<br />consacrées plus précisément aux méthodes théoriques discutées dans ce manuscrit.