This thesis is dedicated to the development, implementation and application of a combination of Density Functional Theory and Dynamical Mean Field Theory. The resulting program is shown through several examples to be a powerful and flexible tool for calculating the electronic structure of strongly correlated materials. The main part of this work is focused on the development and implementation of three methods for solving the effective impurity model arising in the Dynamical Mean Field Theory: Hubbard-I approximation (HIA), Exact Diagonalization (ED), and Spin-Polarized T-matrix Fluctuation-exchange (SPTF). The Hubbard-I approximation is limited to systems where the hybridization between the 4f-orbitals and the rest of the material can be completely neglected, and can therefore not capture any Kondo physics. It has been used to study the atomic-like multiplet spectrum of the strongly localized 4f-electrons in the Lanthanide compounds YbInCu4, YbB12, Yb2Pd2Sn, YbPd2Sn, SmB6, SmSn3, and SmCo5. The calculated spectral properties are shown to be in excellent agreement with experimental direct and inverse photoemission data, clearly affirming the applicability of the Hubbard-I approximation for this class of systems if we are not focusing on Kondo physics. Full self-consistence in both self-energy and electron density is shown to be of key importance in the extraction of the magnetic properties of the hard permanent magnet SmCo5. The Exact Diagonalization solver is implemented as an extension of the Hubbard-I approximation. It takes into account a significant part of the hybridization between the correlated atom and the host through the use of a few effective bath orbitals. This approach has been applied to the long-standing problem of the electronic structure of NiO, CoO, FeO, and MnO. The resulting spectral densities are favorably compared to photoemission spectroscopy. Apart from predicting the correct spectral properties, the Exact Diagonalization solver also provides full access to the many-body density operator. This feature is used to make an in-depth investigation of the correlations in the electronic structure, and two measures of the quantum entanglement of the many-body ground-states are presented. It is shown that CoO possesses the most intricate entanglement properties, due to a competition between crystal field effects and Coulomb interaction, and such a mechanism likely carries over to several classes of correlated electron systems. The Exact Diagonalization solver has also been applied to the prototypical dilute magnetic semiconductor Mn doped GaAs, a material of great importance in the study of future spintronics applications. The problem of Fe impurities in Cs has been used to study the dependence of the spectral properties on the local environment. Finally, the Spin-polarized T-matrix Fluctuation-exchange solver has been implemented and applied to more delocalized electron systems where the effective impurity problem can be solved as a perturbation with respect to the strength of the local Coulomb interaction. This approach has been used to study the magnetic and spectral properties of the late transition metals, Fe, Co and Ni, and NiS.

This thesis focus on the magnetic behavior, from single atoms to bulk materials. The materials considered in this thesis have been studied by computational methods based on ab initio theory, density functional theory (DFT), including treatment of the spin-orbit coupling, non-collinear magnetism, and methods capable of treating discorded systems. Furthermore strongly correlated materials have been investigated using the dynamical mean field theory (DMFT). The uniaxial magnetic anisotropy energy (MAE) of the Fe2P was investigated using the full-potential linear muffin tin orbital (FP-LMTO) method. Based on a band structure analysis, the microscopical origin of the large magnetic anisotropy found for this system is explained. It is also shown that by straining the crystal structure, the MAE can be enhanced further. This opens up for the possibility of obtaining a room temperature permanent magnet based on the Fe2P. The spectral properties of Fe impurities in a Cs host have been investigated, for both surface and bulk systems, by means of combination of density-functional theory in the local density approximation and the dynamical mean-field theory (LDA+DMFT), using two different impurity solvers, the Hubbard I approximation (HIA) and the Exact Diagonalization (ED) method were used. It is shown that noticeable differences can be seen in the unoccupied part of the spectrum for different positions of Fe atoms inside the host. The calculations show good agreement with the experimental photoemission spectra. The stability of the 12-fold metal-phosphorous coordination, existing in the meteorite mineral melliniite has been investigated trough total energy calculations using the coherent potential approximation (CPA) combined with an analysis of the chemical bonds, performed by balanced crystal overlap population (BCOOP). It was shown that its uniquely high metal–phosphorous coordination is due to a balance between covalent Fe–P binding, configurational entropy and a weaker nickel–phosphorus binding. Supported clusters have drawn a lot of attention as possible building blocks for future data storage applications. This topic was investigated using a real space noncollinear formalism where the exchange interactions between Co atoms were shown to be tuned by varying the substrate surface composition. Furthermore the spin dynamics of small Co clusters an a Cu(111) surface have been investigated and a new kind of dynamics, where magnetization switching can be accelerated by decreasing the switching field, has been found. A method for calculating the electronic structure for both ordered and disordered alloys, the augmented space recursion (ASR) method, have been extended to treat non-collinear magnetic order. The method has been used to investigate the energy stability of non-collinear arrangements of MnPt and Mn3Rh alloys.

Porous materials have application in adsorption based processes due to their high internal surface area and tailorable pore size. They find uses in fields such as catalysis, separation, biotechnology, and microelectronics. Fluids confined in such materials exhibit interesting behavior in regards to the condensation and evaporation mechanisms. Understanding study the behavior of fluids confined in these porous materials is necessary for the efficient design of these materials. The adsorption/desorption isotherm provides valuable information about the effect of network features like pore connectivity and pore size distribution on fluid behavior during pore condensation and evaporation. Such insight can be useful in the characterization of these porous materials. Three dimensionally ordered mesoporous (3DOm) carbon is a porous material that has recently emerged and is of interest. These porous structures are obtained from templating colloidal crystals formed from lysine-silica nanoparticles. The resulting structure consist of spherical pores connected to each other by windows. Due to the use of silica nanoparticles a range of tunable pore sizes can be obtained. These structures have high degree of order. They find applications in the synthesis of zeolites due to their highly controllable pore size. Hence a study of the adsorption properties of these structures is of importance. Molecular modeling has proved effective in the study of porous materials. The development of the density functional theory (DFT) and the dynamic mean field theory (DMFT) has led to great advances in the study of the behavior of confined fluids. The DFT enables the study of the adsorption desorption hysteresis phenomena of confined fluids. The DMFT describes the density profile versus time for a step change in relative pressure on the isotherm. These theories have been applied in the past to two dimensional model pore networks to investigate the mechanisms of adsorption and desorption. In this research project we aim to apply the same to various model 3DOm carbon pore networks. Studying the density distributions in these networks can help understand the thermodynamics of fluid adsorption and desorption in these structures. The results could be useful in understanding the effect of pore structure features like pore size and windows on adsorption and desorption. Also the effect of disorder in the pore network as well as effect of variation in pore size on fluid behavior can be studied. Study of the dynamics of adsorption gives an insight into the nucleation mechanisms that govern the condensation of fluid in the pore. These results could prove useful in the characterization of these porous structures.

Dans cette thèse on s'intéresse aux propriétés spectrales et optiques des matériaux aux corrélations fortes de Coulomb. En introduisant un schéma pour la continuation analytique des énergies propres de Matsubara sur l'axe réel dans le cadre le plus général de la théorie de champ moyen dynamique des clusters, les propriétés spectrales résolues en angles deviennent accessibles. De plus, dans certaines approximations, ceci permet la détermination des propriétés optiques. Notamment, on développe dans cette thèse un formalisme pour la conductivité optique dans le langage d'une base localisée. En généralisant la substitution de Peierls pour les cas réalistes de plusieurs atomes par cellule élémentaire, nous obtenons une approche très flexible et facile a implémenter. Ces techniques sont appliquées à plusieurs composés: *l'oxyde de vanadium VO2* Alors que sa phase métallique est caractérisée par des forts effets de corrélations dynamiques, le spectre du VO2 isolant est bien décrit dans un langage à un particule, que l'on définira. L'image de l'isolant qui se forme à partir de notre analyse est celle d'un "isolant de Peierls à N particules". De plus, on calcule la conductivité optique des deux phases et on trouve un accord satisfaisant avec des expériences récentes. Finalement, on en déduit aussi la couleur du matériau. *les sesqui-oxyde des terres rares RE2O3 (RE=Ce, Pr, Nd, Pm)* Dans cette série on trace l'influence des orbitales 4f dans la bande interdite d'excitation et dans les spectres optiques. On trouve un accord raisonnable avec des expériences. *le sesqui-oxyde de vanadium V2O3" Dans notre analyse on trouve que la transition métal-isolant en fonction du dopage avec du chromium est causée par un agrandissement de l'écart due au champ cristallin, résultante des corrélations. Egalement, on trouve une sélectivité orbitale de la cohérence des quasi-particules dans le métal, qui permet à expliquer des résultats expérimentaux optiques récentes.

The purpose of this observational cross-sectional study was to assess the oral health of children between the ages of 6 to 18 with neutropenia attending the Marrow Failure and Myelodysplasia Program at The Hospital for Sick Children and compare the results to healthy control patients attending the Children’s Clinic, Faculty of Dentistry, University of Toronto. Fifteen patients with neutropenia and 26 healthy controls participated in this study. Patients with neutropenia reported an increased incidence of mouth sores and bleeding gums while brushing. However, clinical examination showed no statistical differences in the presence of ulcerations, gingival recession, tooth mobility, gingival inflammation or plaque and calculus levels. The dmft/t and DMFT/T scores were lower for the group with neutropenia, but only the dmft/t score was significant. This data suggests that patients with neutropenia that are being treated by a haematologist do not experience any more severe oral problems than healthy dental patients.

The purpose of this observational cross-sectional study was to assess the oral health of children between the ages of 6 to 18 with neutropenia attending the Marrow Failure and Myelodysplasia Program at The Hospital for Sick Children and compare the results to healthy control patients attending the Children’s Clinic, Faculty of Dentistry, University of Toronto. Fifteen patients with neutropenia and 26 healthy controls participated in this study. Patients with neutropenia reported an increased incidence of mouth sores and bleeding gums while brushing. However, clinical examination showed no statistical differences in the presence of ulcerations, gingival recession, tooth mobility, gingival inflammation or plaque and calculus levels. The dmft/t and DMFT/T scores were lower for the group with neutropenia, but only the dmft/t score was significant. This data suggests that patients with neutropenia that are being treated by a haematologist do not experience any more severe oral problems than healthy dental patients.

Sammanfattning Syfte: En systematisk översikt gjordes vars syfte var att undersöka förekomsten av karies hos vuxna individer som genomgått obesitaskirurgi.  Material och metod: Databaserna som användes för sökningar av artiklar var: PubMed, Web of Science och Cochrane. Ursprungligen identifierades 81 artiklar och fem artiklar bedömdes lämpliga utifrån inklusionskriterierna. Fördelningen var: två kohortstudier, två longitudinella icke-randomiserade interventionsstudier och en tvärsnittsstudie. Totalt utvärderades 345 individer i åldrarna 18–64 år. Uppföljningstiden varierade mellan 6 och 16,9 månader. Litteraturöversikten utformades och dokumenterades enligt PRISMAs metodbeskrivning. Risken för partiskhet bedömdes enligt bland andra NOS och SBU:s granskningsmallar. Resultat: Av de fem artiklar som bedömdes relevanta för inklusion i denna studie var det tre studier som drog slutsatsen att kariesförekomsten ökade hos individer som genomgått obesitaskirurgi. De resterande två artiklarna visade ingen förändring respektive en minskning relaterad till kariesindex.  Slutsats: Det finns en möjlig koppling mellan obesitaskirurgi och en ökad kariesförekomst, dock krävs mer forskning för att kunna styrka sambandet. Att obesitaskirurgin i sig påverkar kariesförekomsten hos vuxna individer kan inte bekräftas. Den faktor som misstänks fortsatt ha en stor påverkan på kariesförekomsten är kostval och ätbeteende. Med den begränsade forskning som finns inom området, bör framtida studier fokusera på längre uppföljningstider och att göra individuella kariesriskbedömningar före och efter obesitaskirurgi. / Abstract Purpose: The purpose of this systematic review was to investigate the caries prevalence in adults having undergone obesity surgery.  Materials and methods: The following databases were used: PubMed, Web of Science and Cochrane. Originally 81 articles were identified and 5 of those were assessed for eligibility for this current study. Two cohort studies, one cross-sectional study and two longitudinal non-randomized studies of intervention were included. In total 345 individuals in the ages between 18 and 64 were evaluated. The evaluation period varied from 6 to 16,9 months. The review was conducted and reported in accordance with the PRISMA guidelines. For assessing risk of bias, the NOS and SBU checklists were used. Results: Three of five studies concluded that a higher caries prevalence was noticed in individuals after bariatric surgery. The remaining two studies could not prove any statistically significant differences regarding to the mean DMFT-index.  Conclusion: There might be a possible link between caries and bariatric surgery, though more research is needed to verify the connection. Considering the limited research available in this field, future studies ought to focus on longer follow-up periods and individual caries risk assessments both before and after bariatric surgery.

Bei der Stippelung handelt es sich um eine Oberflächenstruktur des Gingivaepithels, die der Gingiva ein orangenschalenartiges Aussehen verleiht. Ziel dieser Studie war es, die Stippelung der Gingiva von Kindern zu untersuchen und deren Merkmale sowie Prävalenz zu charakterisieren. Material und Methode: Für diese Querschnittsuntersuchung wurden insgesamt 274 Kinder untersucht (148 Jungen, 126 Mädchen; Durchschnittsalter 4,98 Jahre) und dabei der Zahnbefund, der Mundhygienezustand (API), der Entzündungszustand (PBI) und die ethnische Herkunft aufgenommen. Die Stippelung wurde photographisch und mit Abformung aus niedrig viskösem additionsvernetzenden Silikon dokumentiert. Die davon hergestellten Modelle wurden unter einem Stereomikroskop mit einer Kamera digitalisiert. Das Programm analySIS 3.0 diente zur Bildanalyse. Ergebnisse: Insgesamt zeigten 187 Kinder (68,2%) Stippelung (Jungen 67,2%, Mädchen 69%). Sie trat ab einem Alter von einem Jahr auf. Geschlecht, ethnische Herkunft, Karieserfahrung, API und PBI hatten keinen Einfluss auf die Häufigkeit. Sie kam signifikant häufiger im Wechselgebiss vor, ebenso im Oberkiefer und im Frontzahnbereich. Im Seitenvergleich konnte keine symmetrische Verteilung festgestellt werden. Die Tüpfelung kam bis auf eine Ausnahme ausschließlich auf der befestigten Gingiva vor und war dabei bevorzugt interradikulär, danach radikulär und zuletzt im subpapillären Bereich zu finden. Die Auswertung der Photographien und Replikas ergab eine durchschnittliche Dichte von 2,54 Stippel/mm2 bei einer Höhe von 0,10 mm bzw. einer Breite von 0,09 mm je Vertiefung. Ältere Kinder wiesen eine höhere Dichte der Tüpfelung auf. Alter und Geschlecht keinen Einfluss auf die morphometrischen Daten. Anzahl, Höhe und Breite der Stippelung waren im Oberkiefer und im Frontzahnbereich größer als im Unterkiefer bzw. im Seitenzahnbereich. Schlussfolgerung: Als alleiniges Kriterium zur Beurteilung des klinischen Entzündungszustandes der Gingiva bei Kindern ist die Stippelung nicht geeignet, da das Fehlen von Stippelung nicht immer mit dem Vorhandensein von gingivaler Entzündung übereinstimmt. Für eine korrekte Diagnose müssen vielmehr weitere Kriterien wie Farbe, Dicke, Festigkeit, Kontur der Gingiva, die Sondierungstiefe und Sondierungsblutung einbezogen werden. / Background: The aim of this study was to examine the gingival stippling in children and to characterize it. The prevalence of stippling was a special interest. Stippling is a structure of the gingival epithelium, which causes an orange peel like appearance of the gingiva. Material and methods: In this cross-sectional study 274 children (148 boys and 126 girls; average age 4.98 years) were examined. Oral status, approximal plaque index (API), papillary bleeding index (PBI) and race were noted. Photographs or replicas with a silicone impression material of low viscosity were taken if stippling was found. The replicas were used to make stone casts, which were scanned by a video camera. The obtained pictures were analysed with the software analysis 3.0. Results: 68.2% of the children showed stippling, in 67.2% of the boys and 69.0% of the girls. It was evident from an age of one year. Sex and race did not show any influence on prevalence. There was also no relation between stippling and caries, oral hygiene or gingival inflammation. Stippling was more frequent in mixed dentition than in deciduous dentition. The children showed more stippling in the upper jaw and in the anterior region. It was not spread symmetrically. Usually, it was localized to the attached gingiva with the highest frequency in the interradicular area, followed by the radicular area, and subpapillar area. Only one child showed stippling in the free gingiva, too, but this seemed to be an exception from the rule. The data obtained from photographs and replicas showed a density of 2,54 stipples per mm2, a height of 0.10 mm and a width of 0.09 mm. Older children showed a higher density. Height and width were neither influenced by sex nor by age. But stippling in upper arch and anterior region had a higher density and a larger height and width than in lower arch or posterior region. Conclusion: Gingival Stippling is not a major criterion in clinical assessment of gingival or periodontal inflammation, because missing stippling does not always coincide with presence of gingival inflammation. For a correct diagnosis more criteria, e.g. colour, contour, thickness, consistency, pocket depth and bleeding on probing, have to be considered, too.

Objetivos. Avaliar a associação entre experiência de cárie dental com fatores socioeconômicos e a influência desses fatores na redução dos índices de cárie em crianças de 12 anos de idade nas capitais brasileiras. Métodos. Dados oficiais sobre a experiência de cárie dental (CPO-D) em cada município foram reunidos a partir dos resultados de levantamentos epidemiológicos a respeito de saúde bucal realizados em âmbito nacional nos anos de 1996 e 2002-2003. Dados censitários e provenientes de publicações governamentais a respeito dos indicadores socioeconômicos foram associados à experiência de cárie em 2002-2003, e ao percentual de redução nos índices CPO-D entre 1996 e 2002-2003 utilizando-se análise de regressão linear múltipla. Resultado. Análise de regressão linear simples indicou associação significante entre experiência de cárie e diferentes indicadores socioeconômicos. Resultados da análise de regressão linear múltipla revelaram que menor experiência de cárie esteve associada positivamente ao índice de desenvolvimento humano do município (IDH) e renda per capita. Capitais com menores desigualdades na distribuição de renda (Coeficiente de Gini), menores índices de CPO-D e maior porcentagem de crianças livres de cárie em 2002-2003 apresentaram maiores níveis de redução de cárie. Conclusão. Municípios com melhores perfis socioeconômicos apresentaram uma menor experiência de cárie dental indicando que estratégias públicas de saúde devem ser direcionadas para esses determinantes. Os resultados também sugerem que redução de cárie dental demanda ações governamentais amplas que busquem diminuir as ineqüidades socioeconômicas. / Objectives. Investigate the association between dental caries and socioeconomic indicators in 12-years-old children from Brazilian capitals. Assess the influence of these socioeconomic indicators to dental caries decrease in this population between 1996 and 2003 Methods. Dental caries experience was estimated by gathering data on DMFT index supplied by two country-wide surveys performed in 1996 and 2002- 2003. Measurements of socioeconomic status at city-level used census data and official publications. Association between socioeconomic status with dental caries experience in 2002-2003 and percentage of reduction in DMFT indexes between 1996 and 2002-2003 were fitted using multiple linear regression analysis. Results. Simple linear regression analysis indicated significant associations between DMFT and different socioeconomic factors. Results from multiple linear regression analysis showed that a lower DMFT index was associated with higher values of human development index (HDI) and income. Capitals with lower levels of income inequalities, lowers values of DMFT and highest percentage of caries-free children in 2002-2003, presented highest percentage of DMFT reduction between 1996 and 2002-2003. Conclusions. Capitals with lower socioeconomic status presented highest levels of dental caries than better-off capitals, indicating that public health strategies should target these determinants. The results also suggest that improvements in dental caries experience demand broad governments actions to reduce socioeconomic inequalities.

Objetivos. Avaliar a associação entre experiência de cárie dental com fatores socioeconômicos e a influência desses fatores na redução dos índices de cárie em crianças de 12 anos de idade nas capitais brasileiras. Métodos. Dados oficiais sobre a experiência de cárie dental (CPO-D) em cada município foram reunidos a partir dos resultados de levantamentos epidemiológicos a respeito de saúde bucal realizados em âmbito nacional nos anos de 1996 e 2002-2003. Dados censitários e provenientes de publicações governamentais a respeito dos indicadores socioeconômicos foram associados à experiência de cárie em 2002-2003, e ao percentual de redução nos índices CPO-D entre 1996 e 2002-2003 utilizando-se análise de regressão linear múltipla. Resultado. Análise de regressão linear simples indicou associação significante entre experiência de cárie e diferentes indicadores socioeconômicos. Resultados da análise de regressão linear múltipla revelaram que menor experiência de cárie esteve associada positivamente ao índice de desenvolvimento humano do município (IDH) e renda per capita. Capitais com menores desigualdades na distribuição de renda (Coeficiente de Gini), menores índices de CPO-D e maior porcentagem de crianças livres de cárie em 2002-2003 apresentaram maiores níveis de redução de cárie. Conclusão. Municípios com melhores perfis socioeconômicos apresentaram uma menor experiência de cárie dental indicando que estratégias públicas de saúde devem ser direcionadas para esses determinantes. Os resultados também sugerem que redução de cárie dental demanda ações governamentais amplas que busquem diminuir as ineqüidades socioeconômicas. / Objectives. Investigate the association between dental caries and socioeconomic indicators in 12-years-old children from Brazilian capitals. Assess the influence of these socioeconomic indicators to dental caries decrease in this population between 1996 and 2003 Methods. Dental caries experience was estimated by gathering data on DMFT index supplied by two country-wide surveys performed in 1996 and 2002- 2003. Measurements of socioeconomic status at city-level used census data and official publications. Association between socioeconomic status with dental caries experience in 2002-2003 and percentage of reduction in DMFT indexes between 1996 and 2002-2003 were fitted using multiple linear regression analysis. Results. Simple linear regression analysis indicated significant associations between DMFT and different socioeconomic factors. Results from multiple linear regression analysis showed that a lower DMFT index was associated with higher values of human development index (HDI) and income. Capitals with lower levels of income inequalities, lowers values of DMFT and highest percentage of caries-free children in 2002-2003, presented highest percentage of DMFT reduction between 1996 and 2002-2003. Conclusions. Capitals with lower socioeconomic status presented highest levels of dental caries than better-off capitals, indicating that public health strategies should target these determinants. The results also suggest that improvements in dental caries experience demand broad governments actions to reduce socioeconomic inequalities.