Soluble polymers that have phase selective solubility are useful in synthesis because they simplify purification and separation. Such selectively soluble polymers simplify catalyst, reagent, and product recovery and enable the use of Green chemistry principles in homogeneous catalysis. However, while homopolymers have been reported that have excellent thermal and phase-dependent solubility, less is known about copolymers. Also, less is known about the phase selective solubility of polar aprotic N,N-dialkyl polyacrylamides. This work describes a library synthesis of dye-labeled poly(N-n-octadecylacrylamide-co-N-n-butylacrylamide) copolymers and study of the effects of polymer composition in phase selective solubility of these copolymers. To study the relative importance of n-octadecyl versus n-butyl groups, copolymers with different ratios of n-octadecylacrylamide and n-butylacrylamide but with similar degrees of polymerization and polydispersity were prepared by a split-pool synthesis using a highly soluble poly(N-acryloxy-2-dodecylsuccinimide) as the precursor. Polymer sequestrants were used to remove excess amines and the byproduct N-hydroxyl-2- dodecylsuccinimide without fractionation of the polyacrylamides. Results demonstrated that poly(N-n-octadecylacrylamide-co-N-n-butylacrylamide) copolymers’ phase selective solubility is equally dependant of the polar n-butyl and nonpolar n-octadecyl groups on the copolymers. Dye-labeled poly(N,N-dialkylacrylamide)s prepared by the polymerization of N,N-dialkylacrylamides monomers with methyl, ethyl, propyl, butyl, hexyl, and dodecyl N-alkyl groups in a variety of thermomorphic or latent biphasic polar/nonpolar solvent mixtures were also prepared. Studies showed that poly(N,N-dialkylacrylamide)s have phase selective solubility that is highly dependent of the size of the N-alkyl group. Soluble polymers are known to be useful supports for catalysts. This thesis also describes approaches to immobilization of a variety of catalysts on polyisobutylene (PIB). The most effective of these catalysts were analogs of pyridyl N-oxides that have been used as organocatalysts for the catalytic allylation of a variety of aromatic aldehydes. PIB-supported N-oxide promoted the allylation of aldehydes in up to 99% isolated yield. The products were isolated in the polar phase of a thermomorphic system and the catalyst was recycled through five cycles.

No description available.

This research aims to assess the practice pattern of Canadian emergency physicians for management of anaphylaxis and investigate the clinical predictors for biphasic reactions in children with anaphylaxis. We conducted two studies: a national survey and a multicenter Health Records (HR) review of emergency department visits. Of the 608 physicians surveyed, 340 (56%) responded. Overall, 211(62%) of the physicians correctly agreed that both hypothetical scenarios in the survey were consistent with anaphylaxis, and 206(61%) chose to administer epinephrine. In our HR review, we found five independent predictors of biphasic reactions: age 6-9 years (OR 3.60; 95% CI 1.5-8.58), time from onset of the anaphylactic reaction to ED presentation >90 minutes (OR 2.58; 95% CI 1.47-4.53), wide pulse pressure at triage (OR 2.92; 95% CI 1.69-5.04), treatment of the reaction with >1 dose of epinephrine (OR 2.7; 95% CI 1.12-6.55), and administration of inhaled salbutamol in ED (OR 2.39; 95% CI 1.24-4.62).

Anaplasma phagocytophilum is an obligatory intracellular bacterium that infects neutrophils to cause human granulocytic anaplasmosis. Sialyl Lewis x (sLex)-modified P-selectin glycoprotein ligand-1 (PSGL-1) is the confirmed receptor utilized by A. phagocytophilum to bind and invade human neutrophils and myeloid cell lines. As an obligate intracellular pathogen, the binding of A. phagocytophilum to a host cell receptor is a prerequisite step for entry and replication, and thus its survival. However, the bacterial adhesins mediating this process have yet to be identified. In this study, we sought to identify surface proteins of A. phagocytophilum as putative adhesins. A. phagocytophilum undergoes a biphasic developmental cycle, transitioning between a smaller electron dense-cored cell (DC), which has a dense nucleoid, and a larger, pleomorphic electron lucent reticulate cell (RC), which has a dispersed nucleoid. We determined that the respective roles of the A. phagocytophilum DCs and RCs are adherence/infection and vacuolar replication, respectively, which is a finding that is consistent with the life cycles of other obligate intravacuolar pathogens that undergo biphasic development. Most importantly, we demonstrated the A. phagocytophilum DC is responsible for recognizing human PSGL-1. To identify surface proteins as putative adhesins we tested a variety of approaches. Three different computer prediction programs were compared, resulting in identification of 16 to 130 potential membrane proteins. As a more direct means to identify A. phagocytophilum surface proteins as PSGL-1 adhesins, several affinity capture approaches were tested. We used commercially available recombinant human PSGL-1 (rhPSGL-1) to try and capture adhesins by crosslinking and affinity purification. We were unsuccessful, but nevertheless gained insight into the binding properties of A. phagocytophilum. We next chose to take a broader approach to identify outer membrane proteins of the adherent DC by biotinylation. In the process we developed new density-gradient centrifugation approaches which successfully purified an RC-enriched population as well as a mixed population of RC and DC organisms. Results from this work demonstrate that A. phagocytophilum DC organisms are responsible for binding PSGL-1. Additionally, the results obtained thus far of gradient-purified bacteria will serve as a foundation for future experiments in identifying surface and developmental form specific proteins.

Sustainable technologies are vital to reducing the environmental impact of chemical enterprises. Solvents are often seen as just a medium in which a reaction takes place; however they can also play a dominant role in the overall toxicity of a typical pharmaceutical/fine chemicals batch chemical operation. Further, careful solvent selection for a reaction may also lead to more facile separation and purification of products, thus reducing the overall cost of a chemical process. This thesis presents an environmentally benign processing technique for sustainable biocatalytic reactions coupled with facile built-in separation. An organic aqueous tunable solvent (OATS) system allows access to a hydrophobic substrate which is transformed with a homogeneous enzymatic catalyst in a single liquid phase. Subsequent CO2 addition produces a biphasic mixture where the hydrophobic product partitions preferentially into the organic rich phase for separation while the hydrophilic enzyme catalyst partitions into the aqueous rich phase, where it is recyclable. Processing parameters in OATS systems are discussed and an overall product recovery of 80% is observed after six reaction cycles. Additionally, greater than 99% enantiomeric excess (ee) is shown for catalyzed hydrolysis of rac-1-phenylethyl acetate with Candida antarctica lipase B (CAL B) both before and after CO2-induced separation.

Soluble polymer supports facilitate the recovery and recycling of expensive transition metal complexes. Recently, polyisobutylene (PIB) oligomers have been found to be suitable polymer supports for the recovery of a variety of transition metal catalysts using liquid/liquid biphasic separations after a homogeneous reaction. Our work has shown that PIB-supported Ni(II) and Co(II) β-diketonates prepared from commercially available vinyl terminated PIB oligomers possess catalytic activity like that of their low molecular weight analogs in Mukaiyama epoxidation of olefins. Carboxylic acid terminated PIB derivatives can act as carboxylate ligands for Rh(II) cyclopropanation catalysts. An achiral PIB-supported Rh(II) carboxylate catalyst showed good activity in cyclopropanation of styrene in hydrocarbon solvents, and could be easily recycled nine times by a post reaction extraction. Further application of PIB supports in asymmetric cyclopropanation reactions were investigated using PIBsupported arenesulfonyl Rh(II) prolinates derived from L-proline as examples. The PIBsupported chiral Rh carboxylates demonstrated moderate activity and were recovered and reused for four to five cycles. The prolinate catalyst prepared from PIB-anisole also showed encouraging enantioselectivity and about 8% ee and 13% ee were observed on trans- and cis-cyclopropanation product respectively. Finally, PIB oligomers can be modified in a multi step sequence to prepare PIBsupported chiral bisoxazolines that can in turn be used to prepare active, recyclable PIBsupported Cu(I) bisoxazoline complexes for olefin cyclopropanation. These chiral copper catalysts showed moderate catalytic activity and good stereoselectivity in cyclopropanation of styrene. A chiral ligand prepared from D-phenylglycinol provided the most effective stereo control and gave the trans- and cis-cyclopropanation product in 94% ee and 68% ee respectively. All three PIB-supported chiral bisoxazoline-Cu(I) catalysts could be reused five to six times.

No description available.

The hydroformylation of oct-1-ene is investigated under fluorous biphasic conditions, utilising the facile catalyst recovery that is provided by the temperature dependent miscibility of the perfluorinated solvent with normal organic solvents. High conversions and selectivities have been obtained in the batch process and the system is now described under continuous-flow conditions in a custom built reactor. The continuous-flow reactor was successfully run for 46 hours, with conversions to nonanal of 60% and l:b ratios of approximately 10. To understand the mechanism of this reaction more fully, a spectroscopic study of the catalyst formation and hydroformylation reaction was undertaken, using high-pressure infrared (HPIR) and nuclear magnetic resonance (HPNMR) techniques. The results of this study showed that although there is some effect of the strongly electron withdrawing nature of the perfluorinated ligand, the species formed under reaction conditions are very similar to those formed under the analogous triphenylphosphine system. It was found that under reaction conditions the perfluorinated ligand formed both the bis- and tris- phosphine complexes, compared to triphenylphosphine, which only formed the bis-phosphine complexes. The equatorial-equatorial and equatorial-axial isomers of [RhH(CO)₂(P(C₆H₄C₆F₁₃)₃)₂] were identified by means of a deuterium study in the HPIR spectrometer. The low levels of phosphorus and rhodium leaching to the organic phase were attributed to the predominant formation of [RhH(CO)(P(C₆H₄C₆F₁₃)₃)₃] under ambient pressure and temperature (separator conditions) indicated by a well defined quartet in the metal hydride region of the ¹H NMR spectrum.

This thesis describes a novel approach to augmenting the combustion performance of hybrid rocket fuels, specifically in terms of regression rate and combustion efficiency. Liquid additives are emulsified into molten paraffin wax using nonionic surfactants and cured to form cylindrical fuel grains. Fuel grains were tested in a lab scale, optically accessible hybrid rocket motor and compared to the performance of neat paraffin fuel grains.

Um dos grandes desafios para o tratamento de defeitos ósseos extensos na região bucomaxilofacial têm sido o desenvolvimento de um biomaterial substituto ósseo ao enxerto autógeno. No presente trabalho avaliou-se a formação óssea e a biodegrabilidade do osso desproteinizado bovino Bio-Oss® e do seu similar GenOx Inorg® e da cerâmica bifásica GenPhos® XP no processo de reparo de defeitos ósseos cranianos em coelhos, comparativamente ao osso autógeno (controle positivo) e coágulo sanguíneo (controle negativo). Foram realizados cirurgicamente defeitos bilaterais de 8-mm de diâmetro nos ossos parietais de 39 coelhos. A seguir os defeitos foram preenchidos aleatoriamente com 0,1cm3 de material ou coágulo conforme cada grupo de tratamento. Após os períodos de 4, 8 e 24 semanas os crânios foram coletados, analisados no microtomógrafo e processados histologicamente. O percentual de volume do defeito ocupado pelo material e osso neoformado foi avaliado pela microtomografia e histomorfometria, enquanto que, para a medula óssea, tegumento e tecido conjuntivo, apenas pela análise histomorfométrica. Os resultados quantitativos obtidos foram comparados estatisticamente pela ANOVA a dois critérios (período e tratamento) e teste de Tukey com p<0,05. A intensidade da associação linear dos dados microtomográficos e histomorfométricos avaliada pelo coeficiente de correlação de Pearson, mostraram correlação moderada a forte. Nos períodos iniciais de reparo (30 e 60 dias), os defeitos tratados com Bio-Oss®, GenOx® Inorg e GenPhos® XP apresentaram manutenção do volume do material enxertado (Vvi médio de 34% ) e formação óssea menor e mais imatura em relação grupo autógeno (Vvi = 22% vs. 32% no grupo autógeno). No período mais tardio (180 dias) a quantidade de formação óssea foi estatisticamente similar nos grupos Bio-Oss® (Vvi = 27%), GenOx® Inorg (Vvi = 26%) e GenPhos® XP (Vvi = 20%) porém, o GenOx® Inorg promoveu a formação de um tecido ósseo mais organizado e com maior acúmulo de biomaterial+osso+medula óssea (Vvi = 67,9%) comparado ao GenPhos® XP (Vvi =58,9%) e Bio Oss (Vvi = 55,6%) mas, inferior ao do enxerto autógeno (Vvi = 78%). Os resultados aqui obtidos permitem concluir que o osso autógeno promove rápida formação e maturação óssea, porém não consegue promover o reestabelecimento completo da díploe removida cirurgicamente. Os materiais BioOss, GenOx® Inorg e GenPhos® XP são excelentes materiais osteocondutores levando a formação óssea em toda extensão do defeito, sendo o GenOx® Inorg o que apresenta menor grau de reabsorção e maior e melhor preenchimento do defeito. / One major challenge for treatment of critical size defects in maxillofacial region has been the development of a substitute biomaterial to the autogenous bone grafts. In present study we evaluated the bone formation and biodegradability of deproteinized bovine bone Bio-Oss® and GenOx® Inorg, and biphasic calcium phosphate GenPhos XP® during bone repair process in rabbits cranial defects compared to autogenous bone (positive control) and blood clot (negative control). In parietal bone of 39 rabbits were made bilateral 8-mm diameter defects, which were filled randomly with 0,1cm3 material or clot as each treatment group. After periods of 4, 8 and 24 weeks skulls of animals were collected, analyzed the MicroCT scanner and histologically processed. The percentage of defect volume occupied by biomaterial and new-formed bone were assessed by histomorphometry and microtomography, while the bone marrow, connective tissue and tegument only by first analysis. The quantitative data were compared by two-way ANOVA analysis (time and treatment) and Tukey\'s test at p <0.05. The intensity of the linear association of MicroCT and morphometric data evaluated by the Pearson correlation coefficient, showed moderate to strong correlation. In the early repair periods (30 and 60 days), the defects treated with Bio- Oss, GenOx® Inorg and GenPhos® XP showed maintenance of the graft material volume (average Vvi of 34%) and lower and more immature bone compared autograft group (Vvi = 22% vs. 32% in the autograft group). In the later period (180 days) the amount of bone formation was statistically similar to the groups Bio-Oss® (Vvi = 27 %), GenOx® Inorg (Vvi = 26%) and GenPhos® XP (Vvi = 20%) however, the bone formation in GenOx® Inorg was more organized and with greater accumulation of particles + bone tissue + bone marrow (Vvi = 67.9%), when compared to GenPhos® XP (Vvi = 58.9%) and Bio-Oss® (Vvi = 55.6%) but lower than the autograft (Vvi = 78%). It was concluded that the autogenous bone promotes rapid bone formation and maturation, but cannot promote the complete reestablishment of diploe surgically removed. The Bio-Oss®, GenOx® Inorg and GenPhos® XP are excellent osteoconductive materials leading to bone formation in the full extent of the defects, and the GenOx® Inorg showing less absorption promotes more and better defect filling.