Foram estudados na presente tese alguns aspectos da dinâmica oscilatória de sistemas envolvendo bromato em meio ácido e usando a 1,4-ciclohexanodiona (1,4-CHD) como substrato orgânico. Especificamente, os seguintes sistemas foram estudados: bromato/1,4-CHD/ácido (S1), bromato/1,4-CHD/ferroína/ácido (S2 : S2a e S2b) e bromato/1,4-CHD/trisbipiridina rutênio/ácido (S3). As investigações foram feitas por meio de sondas eletroquímicas e espectroscópicas na região do UV/Vis, em cinco temperaturas entre 5 °C e 45 °C. Parte dos resultados experimentais foram discutidos com a ajuda de simulações numéricas realizadas para os três sistemas. Experimentos espaço-temporais foram realizados em um reator quasi-2D para o sistema S2b. Energias de ativação (Ea) foram estimadas de diferentes formas em regimes pré-oscilatório e oscilatórios. Em todos os casos, a Ea depende do catalisador, composição e concentrações iniciais. Adicionalmente, verificou-se que a ferroína e o trisbipiridina rutênio atuam como catalisadores apenas na transição entre o período de indução e o regime oscilatório. Por meio de simulações numéricas foi possível ilustrar como se classificam as reações em processos que contribuem para o aumento ou decréscimo do período oscilatório. No S2a, oscilações nos comprimentos de onda 364nm e 613nm foram atribuídas à interação da hidroquinona (H2Q) com ferriína; e em 446nm, 487nm e 529nm, à interação H2Q-ferroína. No S3, oscilações em 364nm, 423nm, 454nm e 487nm, foram atribuídas à interação H2Q-[Ru(bpi)3]2+. Os padrões espaço-temporais observados foram facilmente visualizados e não apresentaram bolhas. Estruturas na forma de alvo com comprimento de onda característico de 1,3cm e velocidade de propagação de 0,012cm·s-1 foram claramente observadas. / Some aspects of the oscillatory dynamics in systems consisting of bromate in acidic media with 1,4-cyclohexanedione (1,4-CHD) as the organic substrate were investigated in the present thesis. In particular, the following systems were studied: bromate/1,4-CHD/acid (S1), bromate/1,4-CHD/ferroin/acid (S2 : S2a e S2b) e bromate/1,4-CHD/trisbipyridine ruthenium/acid (S3). Investigations were carried out by means of electrochemical and spectroscopic (in the UV/Vis region) probes, at five temperatures between 5 °C and 45 °C. Some experimental results were discussed in connection with numerical simulations carried out for the three systems investigated. Spatio-temporal experiments in a quasi-2D reactor were performed for the S2b system. Activation energies (Ea) were estimated in different ways for pre-oscillatory and oscillatory regimes. In any case, the Ea was found to depend on the catalyst, composition and initial concentrations. In addition, it was observed that ferroin and trisbipyridine ruthenium act as catalysts only during the transition between the induction period and oscillatory regime. Numerical simulations helped establishing the impact of some individual steps on the oscillatory period. For the system S2a, oscillation in the spectroscopic signals at 364nm and 613nm were attributed to the interaction between hydroquinone (H2Q) and ferriin; and at 446nm, 487nm and 529nm, to the interaction H2Q-ferroin. For the S3, oscillations at 364nm, 423nm, 454nm and 487nm, were attributed to the interaction H2Q-[Ru(bpi)3]2+. The spatiotemporal patterns observed were of very good visual quality and no bubble evolution was detected. Evolving target patterns with characteristic wavelength of 1,3 cm and propagating velocity of 0,012cm·s-1 were clearly observed.

Foram estudados na presente tese alguns aspectos da dinâmica oscilatória de sistemas envolvendo bromato em meio ácido e usando a 1,4-ciclohexanodiona (1,4-CHD) como substrato orgânico. Especificamente, os seguintes sistemas foram estudados: bromato/1,4-CHD/ácido (S1), bromato/1,4-CHD/ferroína/ácido (S2 : S2a e S2b) e bromato/1,4-CHD/trisbipiridina rutênio/ácido (S3). As investigações foram feitas por meio de sondas eletroquímicas e espectroscópicas na região do UV/Vis, em cinco temperaturas entre 5 °C e 45 °C. Parte dos resultados experimentais foram discutidos com a ajuda de simulações numéricas realizadas para os três sistemas. Experimentos espaço-temporais foram realizados em um reator quasi-2D para o sistema S2b. Energias de ativação (Ea) foram estimadas de diferentes formas em regimes pré-oscilatório e oscilatórios. Em todos os casos, a Ea depende do catalisador, composição e concentrações iniciais. Adicionalmente, verificou-se que a ferroína e o trisbipiridina rutênio atuam como catalisadores apenas na transição entre o período de indução e o regime oscilatório. Por meio de simulações numéricas foi possível ilustrar como se classificam as reações em processos que contribuem para o aumento ou decréscimo do período oscilatório. No S2a, oscilações nos comprimentos de onda 364nm e 613nm foram atribuídas à interação da hidroquinona (H2Q) com ferriína; e em 446nm, 487nm e 529nm, à interação H2Q-ferroína. No S3, oscilações em 364nm, 423nm, 454nm e 487nm, foram atribuídas à interação H2Q-[Ru(bpi)3]2+. Os padrões espaço-temporais observados foram facilmente visualizados e não apresentaram bolhas. Estruturas na forma de alvo com comprimento de onda característico de 1,3cm e velocidade de propagação de 0,012cm·s-1 foram claramente observadas. / Some aspects of the oscillatory dynamics in systems consisting of bromate in acidic media with 1,4-cyclohexanedione (1,4-CHD) as the organic substrate were investigated in the present thesis. In particular, the following systems were studied: bromate/1,4-CHD/acid (S1), bromate/1,4-CHD/ferroin/acid (S2 : S2a e S2b) e bromate/1,4-CHD/trisbipyridine ruthenium/acid (S3). Investigations were carried out by means of electrochemical and spectroscopic (in the UV/Vis region) probes, at five temperatures between 5 °C and 45 °C. Some experimental results were discussed in connection with numerical simulations carried out for the three systems investigated. Spatio-temporal experiments in a quasi-2D reactor were performed for the S2b system. Activation energies (Ea) were estimated in different ways for pre-oscillatory and oscillatory regimes. In any case, the Ea was found to depend on the catalyst, composition and initial concentrations. In addition, it was observed that ferroin and trisbipyridine ruthenium act as catalysts only during the transition between the induction period and oscillatory regime. Numerical simulations helped establishing the impact of some individual steps on the oscillatory period. For the system S2a, oscillation in the spectroscopic signals at 364nm and 613nm were attributed to the interaction between hydroquinone (H2Q) and ferriin; and at 446nm, 487nm and 529nm, to the interaction H2Q-ferroin. For the S3, oscillations at 364nm, 423nm, 454nm and 487nm, were attributed to the interaction H2Q-[Ru(bpi)3]2+. The spatiotemporal patterns observed were of very good visual quality and no bubble evolution was detected. Evolving target patterns with characteristic wavelength of 1,3 cm and propagating velocity of 0,012cm·s-1 were clearly observed.

The compound 3-quinuclidinyl benzylate (agent BZ) belongs to the group of incapacitating warfare agents with anticholinergic activity. Today, for its ability to induce functional cognitive impairment (i.e. coordination and memory disorders), the agent BZ is used mainly for scientific purposes in the study of Alzheimer's disease. Despite this fact, its pharmacokinetics has not been fully examined yet. In order to determine the agent BZ in biological material, LC-MS / MS method and sample preparation procedure for body fluids (plasma, bile) and tissues (brain, liver, kidneys) were developed, optimized and validated. The sample preparation procedure for body fluid employed solid phase extraction using a C18 column eluted with methanol and for body tissues it was precipitation with acetonitrile. The chromatographic separation was performed on Gemini NX-C18 reverse phase column (150 × 4.6 mm, 5 μm). The mobile phase consisted of a 10mM solution of ammonium acetate at pH 11 and methanol in a ratio of 30 : 70. Elution of the analytes was performed under isocratic elution. The total analysis time was 5 minutes. Mass spectrometric detection was performed by a linear ion trap using electrospray ionization. Sample preparation procedure and chromatographic analysis methods were successfully applied to real...

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In this thesis, we study the energy extraction from rotating black holes in anti-de Sitter (AdS) spacetime (Kerr-AdS black holes), via the Blandford-Znajek (BZ) process. The motivation is the anti-de Sitter/conformal field theory (AdS/CFT) correspondence which provides a duality between gravitational physics in asymptotically AdS spacetimes and lower dimensional boundary field theories. The BZ process operates via a force-free magnetosphere around black holes and the rotational energy of the black hole is extracted electromagnetically in the form of Poynting flux. The major part of the thesis is devoted to obtaining force-free solutions in the Kerr-AdS background, which generalize traditional BZ solutions in the asymptotically flat Kerr background. Given the solutions, we use the AdS/CFT to infer dual descriptions in terms of the boundary field theory, which hopefully will lead to a better understanding of the energy extraction for rotating black holes. / Graduate

In this thesis, a reversible Lotka-Volterra model was proposed to study the nonlinear oscillation of the Belousov-Zhabotinsky(BZ) reaction in a closed isothermal chemical system. The reaction zone can be divided into two zones, oscillation zone and transition zone, where the oscillation time and the transition time and the number of the complete oscillations are estimated. By applying the geometric singular perturbation method, it was proved that there exist an oscillation axis in the oscillation zone, a strongly stable two-dimensional invariant manifold in transition zone, on which there is also a one-dimensional stable invariant manifold, which is the part of the central axis. There is no oscillation in the vicinity of the equilibrium, as indicated by Onsager's reciprocal symmetry relation. Furthermore, the damped oscillation is studied in terms of the action-action-angle variables. In the end, the model reference control technique is employed to control the oscillation amplitude in the BZ reaction.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-07-20T12:27:21Z No. of bitstreams: 1 raianeaparecidalopesneves.pdf: 1081293 bytes, checksum: de7acb253e8ce7cc8f93a2e3685690c4 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-09T12:50:31Z (GMT) No. of bitstreams: 1 raianeaparecidalopesneves.pdf: 1081293 bytes, checksum: de7acb253e8ce7cc8f93a2e3685690c4 (MD5) / Made available in DSpace on 2017-08-09T12:50:31Z (GMT). No. of bitstreams: 1 raianeaparecidalopesneves.pdf: 1081293 bytes, checksum: de7acb253e8ce7cc8f93a2e3685690c4 (MD5) Previous issue date: 2017-02-21 / A importância e a necessidade do uso de protetores solares, também denominados fotoprotetores, nos últimos anos, é uma realidade inquestionável, visto que protegem a pele contra a radiação ultravioleta. A resolução RDC nº 47 de março de 2006 da Agência Nacional de Vigilância Sanitária (ANVISA) determina quais tipos de filtros podem ser usados em produtos de higiene pessoal, cosméticos e perfumes, bem como sua concentração máxima permitida (10 % para benzofenona-3 - BZ-3, 4 % para 4-metilbenzilideno cânfora – MBC e 10 % para 4-metoxicinamato-2-etilhexila – OMC). Portanto, o presente trabalho teve como objetivo o desenvolvimento de um método eletroanalítico utilizando eletrodos modificados e voltametria de onda quadrada para quantificar BZ-3, MBC e OMC em amostras de protetor solar. Foram otimizadas a composição do eletrólito, eletrodo de trabalho e a técnica voltamétrica aplicada. O sistema eletroquímico consistiu em uma célula com três eletrodos: trabalho – eletrodo de ouro modificado com filme de mercúrio, referência – Ag/AgCl(sat) e auxiliar - platina, como eletrólito foi usado 4,0 mL de Tampão Britton Robinson 0,04 mol.L-1 (pH = 4,0), 1,0 mL de Metanol (grau HPLC) e 5,50 x 10-4 mol.L-1 de brometo de cetiltrimetilamônio. As medidas eletroquímicas foram realizadas por voltametria de onda quadrada, sendo o sistema eletroquímico submetido a purga com argônio por 12 minutos antes das análises. Os limites de detecção (LD) e quantificação (LQ) foram 0,47 mg.L-1 e 1,56 mg.L-1 para BZ-3, 0,77 mg.L-1 e 2,58 mg.L-1 para MBC e 0,78 mg.L-1 e 2,59 mg.L-1 para OMC. O método mostrou valores de recuperação entre 83,3 a 98,1 %. Foram encontrados valores de concentração para BZ-3 de 3,49 % m/m (728 mg.L-1), para MBC de 0,56 % m/m (113 mg.L-1) e para OMC 0,99 % m/m (208 mg.L-1). As amostras de protetor solar foram avaliadas por cromatografia líquida de alta eficiência, como método de referência, demostrando uma boa correlação entre os resultados. Desta forma, todos os valores estão abaixo do permitido pela ANVISA. / In the last few years, the importance and necessity of the use of sunscreen protectors, also denominated photoprotectors, is an unquestionable reality, since they protect the skin against the ultraviolet radiation. The resolution RDC n. 47 of March, 2006 of National Sanitary Vigilance Agency (ANVISA) determines which kinds of filters can be used in personal hygiene products, cosmetics and perfumes, as well as their maximal allowed concentration (10% benzophenone-3 – BZ-3, 4% to camphor 4-metylbenzilidene – MBC and 10% to 2-ethylhexyl-4-methoxycinnamate – OMC). Therefore, the present work has as objective the development of an electroanalytical method utilizing modified electrodes and square wave voltammetry to quantify BZ-3, MBC and OMC in sunscreen protector samples. The electrode composition, work electrode and voltammetric technique were optimized. The electrochemical system consisted of a cell with three electrodes: work – gold electrode modified with mercury film, reference – Ag/AgCl(sat) and auxiliary – platinum, using as electrolyte 4.0 mL of Britton Robinson Buffer 0.04 mol.L-1 (pH = 4.0), 1.0 mL of methanol (HPLC degree) and 5.50 x 10-4 mol.L-1 of cetyltrimethylammonium bromide. The electrochemical measurements were realized by square wave voltammetry, being the electrochemical system under an argon purge for 12 minutes before the analyses. The detection (LD) and quantification (LQ) limits were 0.47 mg.L-1 and 1.56 mg.L-1 to BZ-3, 0.77 mg.L-1 and 2.58 mg.L-1 to MBC and 0.78 mg.L-1 and 2.59 mg.L-1 to OMC. The method showed recovery values between 83.3 and 98.1%. Concentration values found were 3.49% m/m (728 mg.L-1) to BZ-3, 0.56% m/m (113 mg.L-1) to MBC and 0.99% m/m (208 mg.L-1) to OMC. The sunscreen protector samples were evaluated by high performance liquid chromatography, as the reference method, demonstrating a good correlation between the results. In this way, all the values are below of that allowed by ANVISA.

Introduction: Targeted pharmaceuticals for labelling with radio-isotopes for very specific imaging (and possibly later for targeted therapy) play a major role in Theranostics which is currently an important topic in Nuclear Medicine as well as personalised medicine. There was a need for a very specific lung cancer radiopharmaceutical that would specifically be uptaken in integrin 3 expression cells to image patients using a Positron Emission Tomography- Computed Tomography (PET-CT) scanner. Background and problem statement: Cold kits of c (RGDyK)–SCN-Bz-NOTA were kindly donated by Seoul National University (SNU) to help meet Steve Biko Hospital’s need for this type of imaging. These cold kits showed great results internationally in labelling with a 0.1 M 68Ge/68Ga generator (t1/2 of 68Ge and 68Ga are 270.8 days and 67.6 min, respectively). However the same cold kits failed to show reproducible radiolabeling with the 0.6 M generator manufactured under cGMP conditions at iThemba LABS, Cape Town and distributed by IDB Holland, the Netherlands. Materials and methods: There was therefore a need for producing an in-house NOTA-RGD kit that would enable production of clinical 68Ga-NOTA-RGD in high yields from the IDB Holland/iThemba LABS generator. Quality control included ITLC in citric acid to observe labelling efficiency as well as in sodium carbonate to evaluate colloid formation. HPLC was also performed at iThemba LABS as well as Necsa (South African Nuclear Energy Corporation). RGD was obtained from Futurechem, Korea. Kit mass integrity was determined by testing labelling efficiency of 10, 30 and 60 μg of RGD per cold kit. The RGD was buffered with sodium acetate trihydrate. The original kits were dried in a desiccator and in later studies only freeze dried. Manual labelling was also tested. The radiolabelled in-house kit’s ex vivo biodistribution in healthy versus tumour mice were examined by obtaining xenografts. The normal biodistribution was investigated in three vervet monkeys by doing PET-CT scans on a Siemens Biograph TP 40 slice scanner. Results: Cold kit formulation radiolabeling and purification methods were established successfully and SOPs (standard operating procedures) created. HPLC results showed highest radiochemical purity in 60 μg cold kit vials. 68Ga-NOTA-RGD showed increased uptake in tumours of tumour bearing mouse. The cold kit also showed normal distribution according to literature with fast blood clearance and excretion through kidneys into urine, therefore making it a suitable radiopharmaceutical for clinical studies. Conclusion: The in-house prepared cold kit with a 4 month shelf-life was successfully tested in mice and monkeys. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2014

Introduction: Targeted pharmaceuticals for labelling with radio-isotopes for very specific imaging (and possibly later for targeted therapy) play a major role in Theranostics which is currently an important topic in Nuclear Medicine as well as personalised medicine. There was a need for a very specific lung cancer radiopharmaceutical that would specifically be uptaken in integrin 3 expression cells to image patients using a Positron Emission Tomography- Computed Tomography (PET-CT) scanner. Background and problem statement: Cold kits of c (RGDyK)–SCN-Bz-NOTA were kindly donated by Seoul National University (SNU) to help meet Steve Biko Hospital’s need for this type of imaging. These cold kits showed great results internationally in labelling with a 0.1 M 68Ge/68Ga generator (t1/2 of 68Ge and 68Ga are 270.8 days and 67.6 min, respectively). However the same cold kits failed to show reproducible radiolabeling with the 0.6 M generator manufactured under cGMP conditions at iThemba LABS, Cape Town and distributed by IDB Holland, the Netherlands. Materials and methods: There was therefore a need for producing an in-house NOTA-RGD kit that would enable production of clinical 68Ga-NOTA-RGD in high yields from the IDB Holland/iThemba LABS generator. Quality control included ITLC in citric acid to observe labelling efficiency as well as in sodium carbonate to evaluate colloid formation. HPLC was also performed at iThemba LABS as well as Necsa (South African Nuclear Energy Corporation). RGD was obtained from Futurechem, Korea. Kit mass integrity was determined by testing labelling efficiency of 10, 30 and 60 μg of RGD per cold kit. The RGD was buffered with sodium acetate trihydrate. The original kits were dried in a desiccator and in later studies only freeze dried. Manual labelling was also tested. The radiolabelled in-house kit’s ex vivo biodistribution in healthy versus tumour mice were examined by obtaining xenografts. The normal biodistribution was investigated in three vervet monkeys by doing PET-CT scans on a Siemens Biograph TP 40 slice scanner. Results: Cold kit formulation radiolabeling and purification methods were established successfully and SOPs (standard operating procedures) created. HPLC results showed highest radiochemical purity in 60 μg cold kit vials. 68Ga-NOTA-RGD showed increased uptake in tumours of tumour bearing mouse. The cold kit also showed normal distribution according to literature with fast blood clearance and excretion through kidneys into urine, therefore making it a suitable radiopharmaceutical for clinical studies. Conclusion: The in-house prepared cold kit with a 4 month shelf-life was successfully tested in mice and monkeys. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2014