Thesis (Ph. D.)--University of Michigan, 1937. / Cover title. "Reprinted from the Physical review, vol. 52, no. 6, September 15, 1937" with E.R. Gaerttner and H.R. Crane given as authors. Includes bibliographical references.

Thesis (Ph. D.)--University of Michigan, 1937. / Cover title. "Reprinted from the Physical review, vol. 52, no. 6, September 15, 1937" with E.R. Gaerttner and H.R. Crane given as authors. Bibliographical footnotes.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

The expansion of [¹⁸F]-radiolabelling methodologies is vital for the advancement of Positron Emission Tomography (PET) as a medical imaging tool. Novel protocols will simplify access to current PET tracers and allow development of original tracers, potentially enhancing the imaging quality or permit imaging of a wider range of clinical problems. A general introduction is presented in <b>Chapter 1</b>, covering PET, application of fluorine-19 in the pharmaceutical industry, the production of fluorine-18 and the current state-of -art for [¹⁸F]-radiolabelling. The results chapters are divided in to two parts; <b>Part 1</b> (<b>Chapters 2 - 4</b>) concern the synthesis of [18F]fluoroarenes and <b>Part II</b> (<b>Chapters 5</b> and <b>6</b>) discuss diversity oriented radiofluorination techniques, targeting novel [¹⁸F]motifs. In <b>Part I</b>, Chapter 2 describes the use of hypervalent iodine reagents to meditate an umpolung approach for fluorination and radiofluorination of N-arylsulfonamides and anilides. <b>Chapter 3</b> again utilises hypervalent iodine reagents, but as spirocyclic iodonium(III) ylide precursors, being applied to semi-automated and automated microfluidic conditions. <b>Chapter 4</b> discusses the development of conditions for the production and isolation of radiopharmaceuticals employing Cu(II)-mediated radiofluorination of aryl boronic pinacol esters. In <b>Part II, Chapter 5</b> discusses the applicability of halogen exchange reactions to reach polyfluorinated motfis and <b>Chapter 6</b> focuses on the application of a single diazo precursor to access three polyfluorinated motifs with single-step reactions. Finally, <b>Chapter 7</b> provides experimental data for compounds discussed in this thesis.

Fluorocarbons are versatile molecules that are used in multiple industries ranging from pharmaceuticals to refrigerants, insecticides and advanced materials. More particularly hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) are current replacements for ozone-depleting chlorofluorocarbons (CFCs) that were used for decades as refrigerants, propellants, solvents and blowing agents. However, syntheses of HFCs and HFOs involve energy-intensive processes and toxic compounds such as heavy metals and anhydrous HF. Development of more sustainable, energy efficient and "greener" synthesis of small fluorocarbons is needed, which draws attention to organometallic catalysis, especially with abundant, inexpensive and non-toxic transition metals. One approach to new organometallic routes to hydrofluorocarbons involves the formation and functionalization of fluorometallacycles. Previous work in the 1990’s by Baker et al. demonstrated the catalytic hydrodimerization of tetrafluoroethylene (TFE) using Ni catalysts with π-acidic phosphite ligands. They also demonstrated the hydrogenolysis of the d6 ferracyclopentane, Fe(CO)4(1,4-C4F8), 2-1, under high pressure and temperature with different additives to give mixtures of different hydrofluorocarbons. Since that time the reactivity of d8 fluorometallacyles has been extensively studied, leading to fundamental understanding and new catalytic applications. However less attention has been paid to d6 systems, the synthesis and reactivity of which are the focus of this Thesis. Following introduction and background in Chapter 1, Chapter 2 presents the synthesis and characterization of a series of new NHC-, phosphine- and nitrogen-ligand-substituted Fe(II) perfluorometallacycles derived from complex 2-1. This led to the discovery of the first example of a fluorinated metallacyclocarbene obtained from in situ Cα–F bond activation that afforded FeF(triphos)(1,4-C4F7), 2-6, (triphos = bis(2-diphenylphosphinoethyl)phenylphosphine) during the P-based linear tridentate ligand substitution reaction. [Fe(triphos)(1,4-C4F7)(NCMe)]+BPh4-, 2-7, and Fe(OTf)(triphos)(1,4-C4F7), 2-8, were derived from 2-6 by treatment with NaBPh4 in acetonitrile and Me3Si-OTf, respectively (Tf = triflate, SO2CF3). The same phenomenon was not observed with hard-donor N-based linear tridentate ligand, terpy’, (terpy’ = 4′-(4-methylphenyl)-2,2′:6′,2′′-terpyridine), presumably because of the less Lewis acidic metal center. Fluoride abstraction from Fe(terpy’)(CO)(1,4-C4F8), 2-9, by a Lewis acid, however allowed for Cα–F bond activation to give the cationic iron monocarbonyl carbene complex, [Fe(terpy’)(CO)(1,4-C4F7)]+OTf–, 2-10. Chapter 3 investigates further the reactivity of these new Fe(II) perfluorometallacycle complexes. The lack of reactivity of the mono- and di-substituted Fe carbonyl perfluorometallacycles with Lewis acids confirmed that Cα–F bond activation only occurs when there is enough π-backbonding into the Cα–F anti-bonding orbital, as π-acceptor phosphines and carbonyl ligands can compete for the metal back-bonding. Indeed, Cα–F abstraction is only observed with Fe(terpy’)(CO)(1,4-C4F8), 2-9, due to the poor acceptor ability of the nitrogen ligand. On the other hand, the lack of electron density on the metal center can cause the Fe center to act as an internal Lewis acid, promoting Cα–F migration as observed in situ during the triphos substitution reaction. These results show that d6 [Fe] perfluorometallacycles do not share similar reactivity with d8 [Ni] perfluorometallacycles. Moreover, the study of the character of the Fe=CF bonds suggests a nucleophilic carbene for 2-6, while 2-7, 2-8 and 2-10 all displayed electrophilic carbene character. Furthermore, hydrogenolysis of Fe(OTf)(triphos)(1,4-C4F7), 2-8, and [Fe(triphos)(1,4-C4F7)(NCMe)]+BPh4-, 2-7, at low pressure and room temperature, generated exclusively H(CF2)3CFH2, HFC-347pcc, and iron hydrides, confirming a previous hypothesis that attributed formation of this hydrofluoroalkane to an Fe carbene intermediate. In contrast, [Fe(terpy’)(CO)(1,4-C4F7)]+OTf–, 2-10, reacts with H2 to yield HF and an unidentified iron complex, showing that the nature of the ancillary ligands greatly influences the reactivity. Chapter 4 explores the reactivity of phosphine-substituted cobalt(I) carbonyl hydride complexes towards TFE to expand our work on d6 perfluorometallacycles. The most electron-rich ligands prevented metallacycle formation or slowed it down possibly due to strong π-backbonding into the CO ligands, making it harder to generate an open coordination site. Indeed, a mixture of the Co-tetrafluoroethyl complex, derived from insertion of TFE into Co–H, and the zerovalent dimer/hydrogenated TFE products, derived from the reaction of the Co–H with the 16e- CoLn(CO)3-n(CF2CF2H) intermediate, were obtained with the bulkiest ligands, CoH(dcppe)(CO)2 and CoH(Pcp3)(CO)3 (dcppe = 1,2-bis(dicyclopentylphosphino)ethane, cp = cyclopentyl). With the slightly less bulky PiBu3 ligand, further reactivity of the insertion product with TFE slowly formed a d6 metallacycle hydride complex. In contrast, with the dppe and tripod cobalt carbonyl hydrides, metallacycle product formation was evident even at short reaction times with insertion/hydrogenation ratios of 1:1, showing that using less electron-rich, steric bulky ligands prevented the bimolecular Co dimer formation, but left enough room for binding a second equivalent of TFE for metallacycle formation. Finally, Chapter 5 summarizes the findings of this Thesis and discusses future directions based on this work.

Made available in DSpace on 2015-06-17T19:34:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-13. Added 1 bitstream(s) on 2015-06-18T12:47:02Z : No. of bitstreams: 1 000829949_20151201.pdf: 153790 bytes, checksum: 66612d7396e959ac945af3d74af96514 (MD5) Bitstreams deleted on 2015-12-01T09:08:30Z: 000829949_20151201.pdf,. Added 1 bitstream(s) on 2015-12-01T09:09:23Z : No. of bitstreams: 1 000829949.pdf: 786808 bytes, checksum: 1524b77f55a10e10c03ebf457f31a356 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Define-se a osteoporose como uma doença sistêmica, caracterizada pela degradação microarquitetônica do osso e diminuição da massa óssea, que promove aumento da fragilidade óssea com risco de fratura. Vários estudos investigaram a utilização de fluoreto de sódio (NaF) para o tratamento contra a osteoporose. O flúor, quando ingerido, pode acumular-se em tecidos calcificados, como dentes e ossos, podendo alterar a qualidade destes tecidos. Além de influenciar o metabolismo ósseo, o flúor também pode alterar a homeostase glicídica. Estudos em ratos demonstraram que o tratamento crônico com NaF (20 mg/L) na água de beber promoveu a diminuição do sinal insulínico e resistência à insulina. Pesquisas apontam o desenvolvimento de um novo eixo endócrino envolvendo os ossos e o metabolismo da glicose e, isto, abre uma perspectiva de opções terapêuticas para o tratamento de várias patologias. Portanto o objetivo do trabalho foi avaliar o efeito da ingestão hídrica com fluoreto de sódio na dose de 50 mg/L em ratas ovariectomizadas em: 1) grau de fosforilação em tirosina do substrato do receptor de insulina (pp185 - IRS-1/IRS-2) em tecido adiposo branco (TAB); 2) concentrações plasmáticas de glicose, insulina, colesteróis, triacilglicerol, TNF-, IL-6, cálcio, osteocalcina e flúor; 3) densidade óssea e propriedades biomecânicas (rigidez, força máxima e tenacidade) em tíbias; 4) análise histomorfométrica. Quarenta e duas ratas Wistar (dois meses de idade) ovariectomizadas foram distribuídas aleatoriamente em dois grupos: 1) grupo controle (OVX-C), o qual foi submetido ao tratamento sem NaF, mas com uma solução de NaCl (9,54 mg/kg p.c.) que contém a mesma quantidade de sódio em relação à do grupo NaF; 2) grupo NaF (OVX-F) que foi submetido ao tratamento com NaF (50 mg/L) administrado na água de beber durante 42 dias. Após esse... / Osteoporosis is defined as a systemic disease characterized by bone degradation microarchitectonic and decreased bone mass, which promotes increased bone fragility and eventual fracture risk. Several studies have investigated the use of sodium fluoride (NaF) in the treatment for osteoporosis. Fluoride when ingested can accumulate in calcified tissues such as teeth and bones and may alter the quality of these tissues. Besides influencing bone metabolism, fluoride can also alter glucose homeostasis. Studies in rats have shown that chronic treatment with NaF (20 mg/L) in the drinking water has promoted the reduction in insulin signaling, and insulin resistance. Researches indicate the developing of a new endocrine axis involving the bones and glucose metabolism, and this opens a perspective of therapeutic options for the treatment of several pathologies. Therefore the aim of the study was to evaluate the effect of water intake with sodium fluoride at a dose of 50 mg/L in ovariectomized rats: 1) tyrosine phosphorylation status of insulin receptor substrate (pp185 - IRS-1 / IRS- 2) in white adipose tissue (WAT); 2) plasma glucose, insulin, cholesterols, triglyceride, TNF-, IL-6, calcium, fluoride and osteocalcin; 3) bone density and biomechanical properties (stiffness, maximum force and toughness) in the tibia; 4) tibia histomorphometric analysis. Fourty-two female Wistar rats (two months old) were ovariectomized and randomly distributed into two groups: 1) control (OVX-C), which was subjected to the treatment without NaF group but with a solution of NaCl (9.54 mg/kg bw) containing the same amount of sodium in relation to the NaF group; 2) NaF group (OVX-F) which was subjected to treatment with NaF (50 mg/L) administered in drinking water for 42 days. After this period, the following evaluations were carried out: 1) tyrosine...

Resumo: O reimplante dentário é a melhor opção para o tratamento da avulsão. Todavia, período extrabucal prolongado ocasiona danos ao ligamento periodontal, que desencadeiam processos de reabsorção radicular externa. O objetivo desse estudo foi avaliar histomorfometricamente, a viabilidade da solução de própole e a de flúor no controle da reabsorção radicular externa no processo de reparo do reimplante tardio. Trinta ratos (Rattus norvegicus albinus, variedade Wistar) tiveram seu incisivo superior direito extraído. Os dentes foram mantidos em meio seco por 60 minutos. Após esse período a papila dentária, o órgão do esmalte e o ligamento periodontal removidos com lâmina de bisturi e a polpa foi extirpada. Os dentes foram divididos em três grupos experimentais: grupo I - dentes imersos em 20 ml de solução de soro fisiológico; grupo II - dentes imersos em 20 ml de solução de fluoreto de sódio fosfato acidulado a 2%; grupo III - imersão dos dentes em 20 ml de solução de própole a 15%. Após 10 minutos de imersão nas soluções, os canais radiculares foram secos e preenchidos com pasta de hidróxido de cálcio e os dentes reimplantados. A eutanásia dos animais ocorreu 60 dias após o ato operatório. Os resultados mostraram presença de reabsorção inflamatória, por substituição e anquilose nos três grupos experimentais, não apresentando diferença significativa quando submetidos à análise comparativa, o que levou a conclusão de que o tratamento da superfície radicular com própole se mostrou semelhante ao do flúor com relação à reabsorção radicular externa. Apesar de não apresentarem diferença estatisticamente significante, houve maior quantidade de reabsorção inflamatória do soro fisiológico quando comparado ao flúor e à própole. / Abstract: Tooth replantation is the best option for treatment of an avulsed tooth. Nevertheless, an extended extraoral period damages the periodontal ligament, and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 minutes. After this time the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided in to three experimental groups: group I - teeth immersed in 20 ml of physiologic saline; group II - teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; group III - teeth immersed in 20 ml of 15% propolis. After 10 minutes of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed the similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared to those treated with fluoride or propolis. However, the comparative analysis did not reveal any statistically signifant differences between the treatment modalities when used for delayed tooth replantation. / Orientador: Sônia Regina Panzarini Barioni / Coorientadora: Cristiane Mara Ruiz de Sousa Fattah / Banca: Ana Paula Farnezi Bassi / Banca: Celso Koogi Sonoda / Mestre

Made available in DSpace on 2014-06-11T19:27:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-12Bitstream added on 2014-06-13T20:56:49Z : No. of bitstreams: 1 barbosa_tf_me_araca.pdf: 715889 bytes, checksum: f9c4cf0b3fff1513c875f5ce77fdf964 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A fluoretação das águas de abastecimento público tem ocasionado significante redução na prevalência da cárie em diferentes populações, entretanto, a exposição ao flúor pelo uso de diferentes métodos tem trazido preocupações quanto ao aumento na prevalência de fluorose dentária. Por isso, estudos sobre os fatores de risco associados à fluorose são necessários, além do acompanhamento contínuo e efetivo da exposição ao flúor, por diferentes meios, incluindo mais recentemente os marcadores biológicos para esse íon, como a unha, que também reflete o nível de exposição crônica, desde que um indivíduo tenha uma ingestão de flúor relativamente constante. Assim, objetivou-se analisar o teor de fluoreto das águas de abastecimento público em diferentes áreas de um município, uma abastecida por poços profundos e outra pela estação de tratamento de água (ETA), e verificar se os teores de fluoretos encontrados refletem diferenças nas concentrações de flúor observadas nas unhas das crianças de 12 anos e na prevalência de fluorose dentária. Para isso, foram selecionados 43 pontos para coleta de amostras de água, abrangendo as 17 fontes de abastecimento existente no município. A população de estudo foi constituída por 60 crianças, de 12 anos de idade, nascidas e moradoras permanentes nas duas áreas de estudo, seguindo os critérios de inclusão, sendo uma com excesso e outra sem excesso de flúor nas águas de abastecimento público. As amostras de água, coletadas mensalmente nos pontos previamente estabelecidos, foram analisadas em duplicata no período de janeiro a dezembro de 2009, utilizando-se um analisador de íons acoplado a um eletrodo específico para flúor. Coletas e análise do flúor nas unhas das crianças foram realizadas, utilizando-se a técnica da microdifusão facilitada por HMDS. Para verificação da fluorose... / The fluoridation of public water supply has caused a significant reduction in the prevalence of caries in different populations, however, exposure to fluoride by using different methods has brought concerns about the increasing prevalence of dental fluorosis. Therefore, studies on the risk factors associated with fluorosis are needed, besides the efficient and continuous monitoring of fluoride exposure by various means, including most recently the biological markers for this ion, such as fingernail, that also reflects the level of chronic exposure, as long as an individual has a relatively constant intake of fluoride. The objective was to analyze the fluoride content of public water supply in different areas of a district, one served by deep wells and one by the water treatment station (WTS), and check if the levels of fluoride found reflect differences in the concentrations of fluoride observed in nails of 12 years old children and the prevalence of dental fluorosis. For this, 43 points were selected to collect water samples, covering the 17 existing sources of supply in the municipality. The study population consisted of 60 children, 12 years old, born and permanent residents in both areas of study, following the inclusion criteria, one with and one without too much fluoride excess in public water supply. Water samples collected monthly in points previously established, were analyzed in duplicate in the period from January to December of 2009, using an ion analyzer coupled to a specific electrode for fluoride. Sampling and analysis of fluoride in children nails were done, using the technique of facilitated microdiffusion HMDS. For verification of dental fluorosis we used the modified DEAN index .Of the total samples studied (n=512), 44% (n=224) had adequate levels and 56% (n =288) inadequate levels, and 10% (n=49) lower levels and 46% (n=239) higher... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:27:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-08Bitstream added on 2014-06-13T18:56:29Z : No. of bitstreams: 1 costa_lf_me_araca.pdf: 314560 bytes, checksum: 035e52d206ef64038c8bc5900df4f760 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A saliva mantém a integridade e saúde do ambiente bucal. Alterações em sua composição e atividade, associadas à hipertensão, poderiam favorecer aparecimento de patologias sistêmicas e na cavidade bucal. O objetivo deste estudo foi avaliar parâmetros bioquímicos da saliva de ratos espontaneamente hipertensos (SHR) aos 30 dias de vida (30d) e aos 3 meses (3M). Nos experimentos foram utilizados ratos machos Wistar e espontaneamente hipertensos (SHR), aos 30 dias e 3 meses de vida. A medida da pressão arterial sistólica foi realizada pelo método indireto de pletismografia de cauda, com a utilização de pletismógrafo adaptado para medidas em ratos. Para a coleta da saliva os animais, sobre efeito de anestesia e estimulados com nitrato de pilocarpina, foram colocados em prancha inclinada e a saliva foi coletada em beckers, mantidos em gelo, por 15 minutos. Para a medida do pH foi utilizado eletrodo específico acoplado ao pHmetro calibrado, a capacidade tamponante foi calculada de acordo com o volume de ácido lático utilizado para reduzir o pH da amostra até 4. As concentrações de fluoreto ([F-]) e íons cálcio ([Ca++]) foram determinadas com eletrodos específicos e microeletrodos de referência acoplados a analisadores iônicos. A determinação da concentração de proteínas totais foi realizada pelo método de Lowry e a atividade da amilase salivar foi medida através de método cinético,utilizando kit comercial. A dosagem de IgA foi feita através da leitura de absorbância pelo espectrofotômetro, através kit comercial. O fluxo salivar estimulado foi menor nos ratos hipertensos de 3 meses, quando comparado aos ratos normotensos Wistar (SHR: 0,015±0.002mL/min/100g; W: 0,025±0,002mL/min/100g). O pH salivar está aumentado no grupo dos SHR de 3 meses (8,3±0,06) em relação aos ratos... / Saliva plays an important role in the maintenance of a healthy oral environment. Hypertension and aging could interfere with salivary activity, leading to systemic and oral diseases. The aim of this study was to evaluate whether the effects of maternal hypertension on salivary activity of SHR pups are carried to the animal’s adult life. The study was conducted employing 30- day-old (30d) male pups of spontaneously hypertensive rats (SHR) and normotensive Wistar rats (W); and 3 months-old male (3M) SHR and Wistar rats. The systolic blood pressure of 3 months-old male SHR and Wistar rats and female SHR and Wistar rats before mating was recorded by indirect tail-cuff plethysmography. Thirty-day-old (pups) and 3-months-old (young) male rats, after a 12-hour fasting, were anesthetized with xylazine and ketamine. The salivary flow (SF) was stimulated by pilocarpine nitrate. Saliva collection was performed according to Bernardes’ method. Immediately after the saliva was collected, the salivary pH was measured with specific electrode connected to pHmetro priory calibrated. The salivary buffer capacity was calculated according to the volume of lactic acid (0,1 mol/L) spent to reduce the salivary pH to 4,0. The saliva protein concentration was determined using the Lowry method, and salivary amylase activity was measured using the kinetic method. The concentration of fluoride ([F-]) and calcium ([Ca++]) was measured using specific electrode connected to a digital ion-analyzer previously calibrated with standard solutions. Results: The salivary flow of 3 months old SHR was lower than the normotensive rats (SHR: 0,015±0.002mL/min/100g; W: 0,025±0,002mL/min/100g). pH was higher in 3 months old SHR group (8,3±0,06) when compared to normotensive rats (7,9±0.0,09) at the same age; between the pups there was no difference in pH... (Complete abstract, click electronic address below)