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Dwarf carbon (dC) stars are main-sequence stars with carbon molecular bands (C_2, CN, CH) in their optical spectra. They are an important class of post-mass transfer binaries since, as main-sequence stars, dCs cannot have produced carbon themselves. Rather, the excess carbon originated in an evolved companion, now a white dwarf, and was transferred to the dC. Because of their complex histories, dCs are an excellent sample for testing stellar physics, including common-envelope evolution, wind accretion, mass transfer efficiencies, and accretion spin-up. However, their fundamental properties remain a mystery, and this impedes efforts to use dCs to constrain the evolution of binary systems. Here, I have investigated the observed properties of dCs, both as a population and as individual objects. Using multi-epoch spectroscopy, I constrained the dC binary fraction to be consistent with 100% binarity. The best-fit orbital separation distribution agrees with the few known dC orbital periods, and suggests a bimodal distribution (one sample with mean periods of hundreds of days, the other thousands of days). I also built a set of optical templates to find and classify additional dCs in spectroscopic surveys. Further, I discovered periodic variability in photometry of 34 dCs, dramatically increasing the number of measured periods. This allowed me to investigate mass transfer mechanisms that are likely to be important in the formation of dCs. Interestingly, some of these objects have short periods (P < 2d), indicating they have gone through a common-envelope phase. I explored the implications of these short-period dCs and how they will allow for constraints to be placed on the physics of common-envelope evolution. Finally, I searched for signs of spin-up and activity in dCs using X-ray emission. From this, I found that dCs are consistent with being rapid rotators, similar to what is observed in samples of normal young dwarfs. In summary, this dissertation presents the most extensive set of dC observational properties that has been compiled to date. I have confirmed the binary origin of dCs and linked some to post-common-envelope binaries. My work has provided a firmer foundation for the use of dCs to explore many essential astrophysical phenomena.

Large numbers of samples often need to be prepared and analysed in surveys of organic pollutants in the environment, but while the methods commonly used in such surveys can provide abundant detail they are generally costly, time-consuming and require large amounts of resources, so there is a need for simpler techniques. The work underlying this thesis assessed the potential utility of more convenient sample preparation and bioanalytical techniques for rapidly screening various environmental matrices that could be useful complements to higher resolution methods. Initially, the utility of a simplified extraction technique followed by an enzyme-linked immunosorbent assay (ELISA) for detecting polycyclic aromatic hydrocarbons (PAHs) in authentic (i.e. unspiked) contaminated soils was explored. The results showed that there are relationships between the structure and cross-reactivity among compounds that often co-occur with target PAHs. However, their potential contribution to deviations between estimates of total PAH contents of soils obtained using ELISA and gas chromatography-mass spectrometry (GC-MS) based reference methods were limited. Instead, the cross-reactivity of target PAHs and the failure to extract all of the PAHs prior to the ELISA determinations were the main reasons for these deviations. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in food and feed matrices, as well as in authentic contaminated soils using different bioanalytical techniques – ELISA and two cell-based bioassays: CAFLUX and CALUX (chemically activated fluorescent/luciferase gene expression) assays. In addition, enhanced sample preparation techniques based on accelerated solvent extraction (ASE) were developed. ASE with integrated carbon fractionation (ASE-C) in combination with CAFLUX produced estimates of PCDD and PCDF contents in fish oil and fish meal that agreed well with results obtained using reference methods. Furthermore, results from ELISA and GC-high resolution MS analyses of extracts of PCDD- and PCDF-contaminated soil samples obtained using an adjusted ASE-C technique were strongly correlated. Finally, the thesis reports the first experiments in which the results of CAFLUX, CALUX, and ELISA determinations of PCDDs and PCDFs in extracts of authentic contaminated soil samples were evaluated and compared to those obtained using a reference method. All of the bioanalytical techniques were found to be sufficiently sensitive, selective, and accurate for use in screening in compliance with soil quality assessment criteria. Overall, the improved sample preparation and bioanalytical techniques examined proved to be useful potential complements to conventional methods, enhancing the analytical framework for PAHs, PCDDs, and PCDFs. However, further validation has to be undertaken before they are applied on a large-scale.

A young man receiving high dose cytosine arabinoside (3g/m2 every 12 hours) for promyelocytic leukemia developed rapidly increasing hyperbilirubinemia and hepatorenal syndrome. The patient had been treated previously with courses of standard dose cytosine arabinoside without hepatic or renal complications. His condition rapidly deteriorated, and he required hemodialysis. The total bilirubin increased to 45.4 mg/dL, but alkaline phosphatase remained normal. Twelve days after starting chemotherapy, the patient died of hepatorenal failure. Liver necropsy revealed mild bile stasis and microvesicular steatosis. We suspect high dose cytosine arabinoside played a major role in causing impairment of bilirubin transport within the hepatocyte in this patient.

Topical exposure to isopropyl alcohol has been reported in the literature to be toxic if sufficient isopropyl alcohol is absorbed (1-5). A clinical case is reported where a 48-y-old female presented with multiple unexplained cardiac and neurological deficits. The woman had developed the deficits over a 6-mo period in which she had been soaking towels with isopropyl alcohol and applying then to her skin overnight to ease arm pain she was experiencing. Cessation of the isopropyl alcohol exposure resolved her deficits within 3 d. A controlled repeat dermal exposure to isopropyl alcohol under clinical observation reproduced the deficits noted with corresponding serum and urine concentrations of isopropyl alcohol and acetone. Cessation of topical isopropyl alcohol exposure lead to subsequent resolution of all toxicities.

Descrevemos modelo original de sinovite experimental em coelhos imunizados com colágeno V com escasso processo inflamatório, intenso remodelamento matricial e vasculite. Analise morfológica e bioquímica foi realizada em coelhas Nova Zelândia (N=20) imunizadas com colágeno do tipo V, comparadas com controles. Foi observado o aumento dos colágenos I, III e V, oclusão do lúmen vascular e escasso processo inflamatório. A análise bioquímica confirmou a fibrose com aumento da síntese de colágeno. Nós postulamos que as alterações sinoviais descritas neste modelo foram conseqüência das particularidades do colágeno V, que promove manifestações imunológicas e clínicas semelhantes à esclerodermia / We described an original model of experimental synovitis in rabbits immunized with collagen V with scant cellular infiltration, intense matrix remodeling and vasculitis. Morphological and biochemical analysis were realized in New Zealand female rabbits (N=20) immunization with type V collagen, compared with control rabbits. It was observed increase of collagen I, III and V, vascular lumen occlusion and scant inflammatory process. Biochemical analysis confirmed the fibrosis with increased synthesis of collagen. We postulate that synovial changes described in this model are consequence of collagen V particularities, which promotes immunologic and clinical manifestations similar to scleroderma

M. Tech. (Chemistry, Faculty of Applied and Computer Science), Vaal University of Technology / The abundance of agricultural waste materials has led to its use as adsorbents for trace metal adsorption. The raw Macadamia nutshell (RMN) powder was treated with a hydrochloric acid solution to obtain acid modified Macadamia nutshells (AMM), and with sodium hydroxide solution to obtain base modified Macadamia nutshells (BMM). Then, the AMM and BMM materials were grafted with 0.5 M, 1 M, and 2 M acrylic acid. The different AMM grafted materials were labelled 0.5 GAM, 1 GAM and 2 GAM representing the different grafting ratios. The same naming order was followed for the BMM grafted materials, that is, 0.5 GBM, 1 GBM and 2 GBM corresponding to different concentrations used. The prepared Macadamia based adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), carbon, hydrogen, nitrogen and sulphur (CHNS) analysis, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The determination of surface properties such as the point of zero charge (pHPZC), bulk density and the surface negative charge was accomplished with appropriate wet chemistry methods. The adsorption of selected trace metals (Cu(II), Cd(II), Co(II), and Cr(VI)) was done in batch experiments. Atomic absorption spectroscopy (AAS) was used for the determination of metal ions concentrations and total Cr. The ultraviolet-visible (UV–Vis) spectroscopy was used for the determination of Cr(VI) concentration remaining in solution after adsorption. The RMN, AMM, and BMM adsorbents showed potential in removing more than 45% Cu(II) ions, but less than 30% for both Cd(II) and Co(II) ions. However, more than 90% removal of Cr(VI) ions was achieved with the same adsorbents. Consequently, only the adsorption of Cr(VI) was further investigated in the study due to the higher removal efficiency displayed by the Macadamia based biosorbents. The optimum adsorption conditions for the RMN, AMM, and BMM materials were found to be pH 2, 100 mg/L initial concentration of Cr(VI), 600 min contact time and 0.2 g adsorbent mass. The ideal conditions for the 0.5 GAM and 0.5 GBM were found to be pH 2, 25 mg/L initial concentration of Cr(VI), 180 min contact time, and 0.15 g adsorbent mass. The optimum temperature was found to be 40℃ for all materials. A volume of 20 mL was used for all batch experiments. The RMN, AMM, BMM, 0.5 GBM, and 0.5 GAM adsorption mechanisms were better described by the Langmuir isotherm which predicted a monolayer sorption process. The kinetic data fitted better to the pseudo second-order rate model which signified a chemisorption type of interaction. The thermodynamic parameters showed that the adsorption reaction was feasible, spontaneous and endothermic. The Macadamia based materials showed greater potential as adsorbents for the adsorption of Cr(VI) ions from aqueous solution compared to the other selected trace metal ions [Cd(II), Cu(II) and Co(II)].

A modificação e/ou a funcionalização de eletrodos têm por objetivos o desenvolvimento de métodos eficazes para a preparação de eletrodos quimicamente modificados (EQMs) que possam aliar melhorias em sua sensibilidade, seletividade e reatividade em relação aos eletrodos base. Entretanto, a estabilidade e a reprodutibilidade dos EQMs quanto ao processo de lixiviação dos modificadores precisam ser melhorados para que se possam obter eletrodos mais robustos com longo tempo de análise. Uma das possibilidades para se obter eletrodos mais estáveis é por meio de uma ligação estável do tipo covalente entre o eletrodo base e o modificador. Desta forma este trabalho tem por objetivo a funcionalização da grafite por meio de uma reação covalente entre os modificadores cloreto de 4-nitrobenzoíla (4-NB), cloreto de 3,4-dihidroxibenzoíla (3,4-DHB) e do cloreto de 2,2?-bipiridina 4,4?-dicarbonílico (2,2-BP) por meio de uma reação de acilação de Friedel-Crafts assistida por radiação de microondas. O material de síntese foi caracterizado por voltametria cíclica, espectroscopia de infravermelho, curvas termogravimétricas e térmicas diferenciais e espectroscopia de impedância eletroquímica em comparação com a mistura física entre a grafite e os modificadores. Além disso, realizou-se uma generalização da síntese de Friedel-Crafts para outros substratos carboníferos eletródicos como os nanotubos e as fibras de carbono, além de algumas aplicações dos materiais funcionalizados, como exemplos, a grafite funcionalizada e as fibras de carbono funcionalizadas com o derivado bipiridínico (GFT-2,2BP e CNF-2,2BP), por meio de uma ligação entre as bipiridinas funcionalizadas covalentemente nos materiais carboníferos e alguns complexos de rutênio tais como [Ru(bpy)2(OH2)2](PF6)2, [RuCl2(PPh3)3] e do precursor RuCl3.3H2O em eletrooxidações de compostos orgânicos. Para a grafite funcionalizada com nitro derivado (GFT-4NB), realizou-se a eletrooxidação de NADH sobre o potencial redox da hidroxilamina/nitroso. Os resultados dos experimentos de EIS demonstram que a grafite funcionalizada possui uma maior resistência que o material obtido por mistura física. Isto seria esperado já que a formação da ligação covalente afeta a deslocalização de elétrons pi. Finalmente esta metodologia seria uma plataforma geral para a preparação de grafite covalentemente modificada com derivados cujas moléculas possui aplicações de interesse. Assim, o material obtido por este método pode ser usado em aplicações como em eletrodos de pasta de carbono, eletrodos impressos, filmes finos e nanocompósitos e mesmo como um catalisador em reações químicas. Desde que a resposta eletroquímica é muito sensível ao eletrólito, este trabalho abriu uma larga variedade de estudos para entender a interação desses materiais no meio aquoso e orgânico. / Modification and/or functionalization of eletrodic materials have been investigated in order to improve the application of chemically modified electrode (CME) regards on their sensitivity, selectivity and reactivity comparing with unmodified substrate. However, the stability and reproducibility of these CME are one of the most important goals to achieve mainly regarding on the lixiviation of the modifier molecule. Quimisorption is one way to obtain very stable modified materials, since the redox mediator is attached to the substrate by covalent bound. Still it is very important to study the stability and chemical reactivity of these materials. The aim of this work is to synthesize graphite, carbon nanotube and carbon fiber with 4-nitrobenzoíl chloride (4-NB), 3,4-dihidroxibenzoíl chloride (3,4-DHB) and 2,2-bipyridine- 4,4-dicarbonil chloride (2,2-BP) in Friedel-Crafts condition mediated by microwave radiation. The materials were characterized by cyclic voltammetry (CV), using carbon paste electrode (CPE), infrared spectroscopy (IR), thermo gravimetric (TG) and differential thermal analysis (DTA) and electrochemical impedance spectroscopy (EIS). All of the synthesized graphite derivatives were compared with the respective physical mixtures. Moreover, graphite derivatives with bipyridine were used as a ligand in the synthesis with [Ru(bpy)2(OH2)2](PF6)2, [RuCl2(PPh3)3] and RuCl3.3H2O. These products were used as electrocatalysts to oxidize alcohols in comparison with the complex incorporated in graphite. Graphite obtained from 4-NB reaction was employed to oxidize NADH in the redox potential of hydroxylamine/nitroso derived. Results from EIS measurements have show that graphite functionalized has higher resistance than the material obtained by physical mixture. This would be expected since the covalent bound would affect a pi electron dislocation. In conclusion, this methodology would be a general platform to prepare graphite and derivatives covalently bounded to molecules that have interesting application. In addition, it\'s been shown that the catalytic property of the respective function organic hasn\'s changed after reaction with carbon substrate. Thus the material obtained by this method could be used in applications such as carbon paste electrodes, finger print electrodes, thin films and nanocomposites and even as a catalyst in chemical reaction. Since the electrochemical response is very sensitive regards on the electrolyte, this work opened a wide range of studies to understand the interaction of these materials in aqueous and organic medium.

Lau Hoi Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 134-157). / Abstracts in English and Chinese. / PUBLICATIONS BASED ON WORK IN THIS THESIS --- p.I / ABSTRACT --- p.II / ACKNOWLEDGEMENTS --- p.VI / TABLE OF CONTENTS --- p.VIII / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Emesis --- p.3 / Chapter 1.2.1 --- Introduction --- p.3 / Chapter 1.2.2 --- Retching & Vomiting --- p.3 / Chapter 1.2.3 --- Nausea --- p.4 / Chapter 1.2.4 --- Motor Components of Emetic Reflex --- p.5 / Chapter 1.2.4.1 --- Pre-ejection Phase --- p.5 / Chapter 1.2.4.2 --- Ejection Phase --- p.5 / Chapter 1.2.4.3 --- Post-ejection Phase --- p.6 / Chapter 1.2.5 --- Components of Emetic Reflex --- p.6 / Chapter 1.2.5.1 --- Area Postrema (AP) --- p.6 / Chapter 1.2.5.2 --- Nucleus Tractus Solitarius (NTS) --- p.7 / Chapter 1.2.5.3 --- Vomiting Centre --- p.8 / Chapter 1.2.5.4 --- Vestibular System --- p.10 / Chapter 1.2.5.5 --- Abdominal Visceral Afferents --- p.10 / Chapter 1.2.5.6 --- Forebrain --- p.11 / Chapter 1.2.6 --- Neurotransmitters & Receptors --- p.12 / Chapter 1.2.7 --- Anti-emetics --- p.13 / Chapter 1.3 --- Models of Nausea --- p.16 / Chapter 1.3.1 --- Introduction --- p.16 / Chapter 1.3.2 --- Conditioned Taste Aversion --- p.18 / Chapter 1.3.3 --- Pica Behaviour --- p.20 / Chapter 1.3.4 --- Studies of the Involvement of Vasopressin --- p.21 / Chapter 1.3.5 --- Tachygastria --- p.24 / Chapter 1.3.6 --- Locomotor Activity --- p.26 / Chapter 1.4 --- Markers of Neuronal Activity --- p.27 / Chapter 1.4.1 --- General Comments --- p.27 / Chapter 1.4.2 --- c-fos Expression as a Marker of Neuronal Activity --- p.28 / Chapter 1.4.2.1 --- What is c-fos? --- p.28 / Chapter 1.4.2.2 --- Regulation of c-fos Expression --- p.30 / Chapter 1.4.2.2.1 --- Calcium Response Element --- p.31 / Chapter 1.4.2.2.2 --- Serum Response Element --- p.32 / Chapter 1.4.2.3 --- Types of Receptors Involved in c-fos Expression --- p.32 / Chapter 1.4.2.4 --- Feasibility of Using c-fos Expression as Marker of Cellular Activity --- p.36 / Chapter 1.4.2.5 --- Identification of Emetic Pathway by c-fos Immunohistochemistry --- p.36 / Chapter 1.5 --- Aims & Objectives --- p.37 / Chapter CHAPTER 2 --- METHODS --- p.42 / Chapter 2.1 --- Animals --- p.42 / Chapter 2.1.1 --- Ferrets --- p.42 / Chapter 2.1.2 --- Suncus murinus --- p.42 / Chapter 2.2 --- Measurement of Animal Behaviour --- p.43 / Chapter 2.2.1 --- Experiment Design --- p.43 / Chapter 2.2.2 --- Recording of Animal Behaviour --- p.43 / Chapter 2.2.3 --- Calibration of Equipment Used to Record Spontaneous Locomotor Activity --- p.44 / Chapter 2.2.4 --- Behaviour Recorded by the Observer --- p.45 / Chapter 2.3 --- Administration of Drugs --- p.46 / Chapter 2.3.1 --- Ferrets --- p.46 / Chapter 2.3.1.1 --- General Comments --- p.46 / Chapter 2.3.1.2 --- Drug Antagonism Studies --- p.47 / Chapter 2.3.2 --- Suncus murinus --- p.47 / Chapter 2.3.2.1 --- General Comments --- p.47 / Chapter 2.3.2.2 --- Dose-Response Studies --- p.48 / Chapter 2.3.2.3 --- Drug Antagonism Studies --- p.48 / Chapter 2.4 --- c-fos Expression Studies in Ferret Brainstems --- p.50 / Chapter 2.4.1 --- Animals and Anaesthesia --- p.50 / Chapter 2.4.2 --- Perfusion and fixation --- p.50 / Chapter 2.4.3 --- Dehydration of brains --- p.51 / Chapter 2.4.4 --- Embedding of tissue --- p.52 / Chapter 2.4.5 --- Sectioning --- p.52 / Chapter 2.4.6 --- Staining --- p.52 / Chapter 2.4.7 --- Antibodies used --- p.55 / Chapter 2.4.8 --- Positive Control Slides --- p.55 / Chapter 2.5 --- Experimental Design and Statistics --- p.56 / Chapter 2.5.1 --- Randomization of Treatments --- p.56 / Chapter 2.5.2 --- Statistics --- p.57 / Chapter 2.5.2.1 --- Ferrets --- p.57 / Chapter 2.5.2.2 --- Suncus murinus --- p.59 / Chapter 2.6 --- Drugs and Chemicals Used --- p.60 / Chapter 2.6.1 --- Drugs Used --- p.60 / Chapter 2.6.2 --- Chemicals Used --- p.62 / Chapter CHAPTER 3 --- RESULTS --- p.63 / Chapter 3.1 --- Ferret --- p.63 / Chapter 3.1.1 --- "The Effect of Ondansetron and CP-99,994 on Emesis and Locomotor Activity Changes Induced by Cisplatin in the Ferret" --- p.63 / Chapter 3.1.2 --- The Effect of Domperidone on Emesis and Locomotor Activity Changes Induced by Apomorphine in the Ferret --- p.69 / Chapter 3.1.3 --- "The Effect of CP-99,994 on Emesis and Locomotor Activity Changes Induced by Apomorphine in the Ferret" --- p.74 / Chapter 3.1.4 --- c-fos Expression Studies in Ferret Brainstems --- p.79 / Chapter 3.1.4.1 --- Cisplatin-treated Ferrets --- p.79 / Chapter 3.1.4.2 --- Positive Control Slides --- p.84 / Chapter 3.2 --- Suncus murinus --- p.88 / Chapter 3.2.1 --- The Emetic Potential of Nicotine and its Effects on the Spontaneous Locomotor Activity of Suncus murinus --- p.88 / Chapter 3.2.2 --- "The Effect of CP-99,994 on Emesis and Locomotor Activity Changes Induced by Nicotine in Suncus murinus" --- p.92 / Chapter 3.2.3 --- The Emetic Potential of Copper Sulphate and its Effects on the Spontaneous Locomotor Activity of Suncus murinus --- p.95 / Chapter 3.2.4 --- "The Effect of CP-99,994 on Emesis and Locomotor Activity Changes Induced by Copper Sulphate in Suncus murinus" --- p.98 / Chapter 3.2.5 --- The Emetic Potential of Cisplatin and its Effects on the Spontaneous Locomotor Activity of Suncus murinus --- p.101 / Chapter 3.2.6 --- The Effect of Ondansetron on Emesis and Locomotor Activity Changes Induced by Cisplatin in Suncus murinus --- p.104 / Chapter 3.2.7 --- "The Effect of CP-99,994 on Emesis and Locomotor Activity Changes Induced by Cisplatin in Suncus murinus" --- p.107 / Chapter 3.2.8 --- "The Effects of Ondansetron and CP-99,994 on Locomotor Activity in Suncus murinus" --- p.110 / Chapter CHAPTER 4 --- DISCUSSION --- p.113 / Chapter CHAPTER 5 --- GENERAL SUMMARY --- p.130 / REFERENCES --- p.134

Descrevemos modelo original de sinovite experimental em coelhos imunizados com colágeno V com escasso processo inflamatório, intenso remodelamento matricial e vasculite. Analise morfológica e bioquímica foi realizada em coelhas Nova Zelândia (N=20) imunizadas com colágeno do tipo V, comparadas com controles. Foi observado o aumento dos colágenos I, III e V, oclusão do lúmen vascular e escasso processo inflamatório. A análise bioquímica confirmou a fibrose com aumento da síntese de colágeno. Nós postulamos que as alterações sinoviais descritas neste modelo foram conseqüência das particularidades do colágeno V, que promove manifestações imunológicas e clínicas semelhantes à esclerodermia / We described an original model of experimental synovitis in rabbits immunized with collagen V with scant cellular infiltration, intense matrix remodeling and vasculitis. Morphological and biochemical analysis were realized in New Zealand female rabbits (N=20) immunization with type V collagen, compared with control rabbits. It was observed increase of collagen I, III and V, vascular lumen occlusion and scant inflammatory process. Biochemical analysis confirmed the fibrosis with increased synthesis of collagen. We postulate that synovial changes described in this model are consequence of collagen V particularities, which promotes immunologic and clinical manifestations similar to scleroderma