Foi investigada a utilização de Sistema Micelar de Duas Fases Aquosas (SMDFA) para remoção de lipolissacarídeos (LPS) de preparações contendo proteínas recombinantes de interesse farmacêutico, como a proteína verde fluorescente (GFPuv). Os SMDFA são constituídos por soluções de tensoativos contendo micelas e oferecem ambientes hidrofóbico e hidrofílico, que possibilitam seletividade na partição de biomoléculas de acordo com sua hidrofobicidade, permitindo a remoção de LPS contaminante. Neste trabalho, foi realizada a implementação do método para a quantificação de LPS em amostras contaminadas e a obtenção de LPS e GFPuv puros a partir de cultivo de E. coli recombinante. Além disso, foi estudada a influência do Triton X-114 na metodologia de quantificação de LPS, e a adição de MgSO4, CaCl2, KI e (NH4)2SO4 na partição de GFPuv e LPS puros em SMDFA. E ainda, realizou-se um planejamento experimental (22) para avaliar os maiores KGFPuv e %RECGFPuv. O homogeneizado celular de E. coli foi testado nas melhores condições obtidas com o planejamento experimental. E finalmente, o processo por cromatografia de afinidade por íons metálicos (IMAC) foi empregado para investigar a adsorção de LPS em matriz IDA-Ca2+. Conforme os resultados obtidos, o TX-114 causou elevada interferência no método cinético cromogênico, em função da similaridade desta molécula com os LPS. Os LPS apresentaram partição preferencial para a fase concentrada em micelas, com altos valores de remoção, %REMLPS>98,0%. Ao contrário, a GFPuv foi recuperada preferencialmente na fase diluída, na qual existe maior volume disponível, resultando em valores de KGFPuv>1. A adição de sais ocasionou diminuição nos valores KGFPuv, provavelmente por causa da carga negativa que GFPuv adquiriu nas condições avaliadas. Os resultados do planejamento experimental mostraram que a melhor condição de partição obtida foi na região do ponto central, 4,0% (p/p) a 60,0°C, com KGFPuv>10. O processo por IMAC apresentou as maiores capacidades de adsorção de LPS-IDA-Ca+2 nas condições de menor pH e maior força iônica 4,0 e 1,0 mol/L, respectivamente. O processo de purificação por SMDFA empregado para a remoção de LPS contaminante presente em meio fermentado contendo GFPuv, demonstrou ser eficiente em recuperar a biomolécula-alvo na fase diluída e separar o principal contaminante na fase rica em micelas. Portanto, pode ser empregado como primeira etapa para a remoção de altas concentrações de LPS na purificação de proteínas hidrofílicas como a GFPuv. / The Aqueous Two-Phase Micellar System (ATPMS) was investigated for endotoxin (LPS) removal from preparations containing recombinant proteins of pharmaceutical interest, such as the green fluorescent protein (GFPuv). These systems usually consist of micellar surfactants solutions and offer both hydrophobic and hydrophilic environments, providing selectivity to the biomolecules partitioning according to its hydrophobicity. In this work, the implementation of the method for LPS quantification in contaminated samples was accomplished, as well as the obtaining of pure LPS and GFPuv from recombinant E. coli. Furthermore, the influence of Triton X-114 in the methodology for LPS quantification was studied, as the addition of MgSO4, CaCl2, KI, and (NH4)2SO4 into the partition of pure GFPuv and LPS in ATPMS. In addition, a statistical design (22) was carried out to evaluate the highest KGFPuv and %RECGFPuv. The E. coli cell lysate was tested under optimum conditions obtained with the statistical design. And, finally, the process by ionmetal affinity chromatography (IMAC) was used to investigate the adsorption of LPS in IDA-Ca2+ matrix. The results showed that the TX-114 caused high interference in the kinetic chromogenic method, according to the similarity of this molecule to LPS. The LPS showed preferential partitioning to the micellerich phase, with high values of removal, %REMLPS>98.0%. In the other hand, the GFPuv was preferentially recovered in the micelle-poor phase, in which there is greater volume available resulting in values of KGFPuv>1. The addition of salts caused a reduction in the values KGFPuv, probably because of the negative charge that the GFPuv acquired at the conditions evaluated. The results of the statistical design showed that the best partitioning condition obtained was in the central point region, 4.0% (wt/wt) at 60.0°C, with KGFPuv>10. The process by IMAC showed the highest adsorption of LPS-IDA-Ca+2 capacities at the conditions of lower pH and higher ionic strength 4.0 and 1.0 mol/L, respectively. The purification process for the LPS contaminant removal from E. coli fermentation containing GFPuv by ATPMS proved to be efficient in the recovering of target biomolecule in the micelle-poor phase, and separating the main contaminant in the micelle-rich phase. Furthermore, this system can be exploited as the first step for removal of higher LPS concentrations from hydrophilics protein purification.

A melamina é um composto tóxico ilegalmente empregado para adulterar o teor de proteínas em leite. A ingestão de pequenas quantidades de melamina pode causar complicações renais e até mesmo a morte de animais e humanos. Os procedimentos usuais para a determinação de proteínas são baseados na quantificação de nitrogênio total e não permitem detectar a adulteração. Neste trabalho, um procedimento rápido e limpo foi desenvolvido para a determinação de melamina como adulterante em leite. Triton X-114 foi utilizado para o clean-up da amostra e como fluoróforo. A determinação da melamina foi baseada na supressão da fluorescência do surfactante na fase pobre após a extração em ponto nuvem. Resposta linear foi observada entre 1,0 e 6,0 mg L- 1 de melamina, descrita pela equação de Stern-Volmer I°/I = 0,999 + 0,0165 CMEL (r = 0,999). O limite de detecção foi estimado em 0,8 mg L- 1 (nível de confiança de 95 %), o que permite a detecção de 320 \'mü\'g de melamina em 100 g de leite. Coeficientes de variação (n = 8) foram estimados em 0,4 e 1,4 % na ausência e na presença do analito, respectivamente. Recuperações entre 95 e 102% e os coeficientes angulares das curvas de calibração obtidas na presença e ausência de leite indicaram a ausência de efeitos da matriz. Os resultados para diferentes amostras de leite concordaram com os obtidos por cromatografia líquida de alto desempenho a um nível de confiança de 95% / Melamine is a toxic compound illegally used to adulterate the protein content in milk. The ingestion even of low amounts of melamine can lead to renal complications and death of animals and humans. Usual procedures for the determination of total nitrogen are not selective for the determination of non-protein nitrogen. In this work, a fast and environmentally friendly procedure was developed for the determination of melamine as a milk adulterant. Triton X-114 was used for sample clean-up and as a fluorophore. Determination of melamine was based on fluorescence quenching of surfactant in the poor phase after cloud point extraction in the presence of melamine. A linear response was observed from 1.0 and 6.0 mg L-1 melamine, described by the Stern-Volmer equation I°/I = 0.999 + 0.0165 CMEL(r = 0.999). The detection limit was estimated at 0.8 mg L-1 level (95% confidence level), which enables detection of as low as 320 \'mü\'g in 100 g of melamine of milk. The coefficients of variation (n = 8) were estimated at 0.4 % or 1.4 % in the absence or presence of the analyte, respectively. Recoveries within 95-102 % and similar slopes of calibration graphs obtained with and without milk indicated the absence of matrix effects. The results for different milk samples agreed with those obtained by high performance liquid chromatography at the 95% confidence level

A melamina é um composto tóxico ilegalmente empregado para adulterar o teor de proteínas em leite. A ingestão de pequenas quantidades de melamina pode causar complicações renais e até mesmo a morte de animais e humanos. Os procedimentos usuais para a determinação de proteínas são baseados na quantificação de nitrogênio total e não permitem detectar a adulteração. Neste trabalho, um procedimento rápido e limpo foi desenvolvido para a determinação de melamina como adulterante em leite. Triton X-114 foi utilizado para o clean-up da amostra e como fluoróforo. A determinação da melamina foi baseada na supressão da fluorescência do surfactante na fase pobre após a extração em ponto nuvem. Resposta linear foi observada entre 1,0 e 6,0 mg L- 1 de melamina, descrita pela equação de Stern-Volmer I°/I = 0,999 + 0,0165 CMEL (r = 0,999). O limite de detecção foi estimado em 0,8 mg L- 1 (nível de confiança de 95 %), o que permite a detecção de 320 \'mü\'g de melamina em 100 g de leite. Coeficientes de variação (n = 8) foram estimados em 0,4 e 1,4 % na ausência e na presença do analito, respectivamente. Recuperações entre 95 e 102% e os coeficientes angulares das curvas de calibração obtidas na presença e ausência de leite indicaram a ausência de efeitos da matriz. Os resultados para diferentes amostras de leite concordaram com os obtidos por cromatografia líquida de alto desempenho a um nível de confiança de 95% / Melamine is a toxic compound illegally used to adulterate the protein content in milk. The ingestion even of low amounts of melamine can lead to renal complications and death of animals and humans. Usual procedures for the determination of total nitrogen are not selective for the determination of non-protein nitrogen. In this work, a fast and environmentally friendly procedure was developed for the determination of melamine as a milk adulterant. Triton X-114 was used for sample clean-up and as a fluorophore. Determination of melamine was based on fluorescence quenching of surfactant in the poor phase after cloud point extraction in the presence of melamine. A linear response was observed from 1.0 and 6.0 mg L-1 melamine, described by the Stern-Volmer equation I°/I = 0.999 + 0.0165 CMEL(r = 0.999). The detection limit was estimated at 0.8 mg L-1 level (95% confidence level), which enables detection of as low as 320 \'mü\'g in 100 g of melamine of milk. The coefficients of variation (n = 8) were estimated at 0.4 % or 1.4 % in the absence or presence of the analyte, respectively. Recoveries within 95-102 % and similar slopes of calibration graphs obtained with and without milk indicated the absence of matrix effects. The results for different milk samples agreed with those obtained by high performance liquid chromatography at the 95% confidence level

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In mammals, the liver plays a central role in whole-body lipid metabolism. Unfortunately, dysregulation of these pathways has been implicated in hyperlipidemias. In recent years, a significant association between the trace element selenium and hypercholesterolaemia in human and animals has been reported. This study was designed to investigate a potential hypolipidaemic effect of diphenyl diselenide ((PhSe)2) in Triton WR-1339-induced hyperlipidaemia in mice. Triton was administered intraperitoneally (400 mg/kg) to overnight-fasted mice to develop acute hyperlipidaemia. (PhSe)2 was administered orally (10 mg/kg) 30 min before Triton. At 24 h after Triton injection, blood samples were collected to measure plasma lipid levels. The hepatic thiobarbituric acid reactive substances and ascorbic acid levels as well as catalase and glutathione peroxidase activity were recorded. (PhSe)2 administration significantly lowered total cholesterol, non-high- density lipoprotein-cholesterol and triglycerides,whilst it increased high-density lipoprotein-cholesterol levels in plasma of hyperlipidaemic mice. Neither oxidative stress nor the antioxidant effect of (PhSe)2 was observed in the mouse liver in this experimental protocol. These findings indicated that (PhSe)2 was able to lower plasma lipid concentrations. Further studies are needed to elucidate the exact mechanism by which (PhSe)2 exerted its hypolipidaemic effect in the management of hyperlipidaemia. / Nos mamíferos, o fígado desempenha um papel extremamente importante na manutenção da homeostase do metabolismo dos lipídios plasmáticos. Entretanto, problemas na regulação desses mecanismos têm sido implicados na ocorrência de dislipidemias (alterações na concentração adequada de lipídios no plasma). Nos últimos anos, tem sido evidenciada a existência de uma relação entre os níveis de selênio (Se) e o aumento nas concentrações plasmáticas de lipídios em humanos e animais. Dessa forma, o presente trabalho teve por objetivo investigar um possível efeito hipolipidêmico do (PhSe)2, um composto orgânico de Se, no modelo de hiperlipidemia aguda induzida por Triton WR-1339 em camundongos, bem como investigar se a hiperlipidemia aguda induzida pela administração intraperitonial (i.p.) de Triton WR-1339 altera parâmetros relacionados à ocorrência de dano oxidativo no tecido hepático de camundongos e determinar se o efeito antioxidante do (PhSe)2 está presente nesse processo. Para isso, o Triton WR-1339 foi injetado i.p. (400 mg/kg) em camundongos que estavam em jejum de 12 horas. O (PhSe)2 foi administrado oralmente (10 mg/kg) 30 minutos antes do Triton WR-1339. 24 horas após a injeção do Triton WR-1339, amostras de sangue foram coletadas para dosagem das concentrações de lipídios plasmáticos. Os níveis de espécies reativas ao ácido tiobarbitúrico (TBARS) e ácido ascórbico, bem como a atividade das enzimas catalase e glutationa peroxidase foram determinados no tecido hepático. A administração de (PhSe)2 foi capaz de prevenir o aumento nos níveis de colesterol total, colesterol não-HDL e triglicerídeos bem como aumentar os níveis de HDL-colesterol no plasma de camundongos hiperlipidêmicos. No protocolo experimental utilizado nesse estudo não foram observadas alterações nos parâmetros hepáticos de estresse oxidativo analisados. Conseqüentemente, o efeito antioxidante do (PhSe)2 não pode ser verificado. Os resultados obtidos nesse trabalho encorajam a realização de estudos posteriores no intuito de elucidar o exato mecanismo através do qual o (PhSe)2 exerce seu efeito hipolipidêmico.

In order to improve the efficiency of dry used nuclear fuel (UNF) storage, reduced reactivity methods are being developed for various reactor types and operating conditions. Sub-criticality must be maintained in the storage configuration and conservative computer simulations are used as the primary basis for loading the storage casks. Methodologies are now being developed to reduce the amount of modeling and computation in order to make conservative assessments of how densely fuel can be packed. The SCALE/TRITON (Standardized Computer Analyses for Licensing Evaluation / Transport Rigor Implemented with Time-dependent Operation for Neutronic Depletion) code system has been used to simulate boiling water reactor (BWR) operating conditions in order to investigate nuclide densities in UNF and how the use of control rod blades affect nuclide densities found in UNF. Rodded and unrodded operating cases for a fuel assembly have been used as bounding cases and are used as reference solutions in a piecewise data approximation methodology (PDA method). A variety of control blade insertion patterns have been used with the PDA method and simulated in TRITON in order to observe trends in nuclide densities with varying control blade use. The PDA method is compared with TRITON simulated data in order to evaluate the validity and accuracy of the PDA method. The PDA method gives very accurate results for fissile nuclides but is insufficient in treating densities as a function of burnup for fission products and fertile nuclides. Predicting nuclide densities from temporally balanced control blade insertion and withdrawal patterns is also a strength of the PDA method. The PDA method, however, is not capable of properly accounting for neutron spectral shifts and the behavior in nuclide densities brought about by the spectral shift or nuclide density saturation. Observing the causes for the shortcomings in the PDA method, a more robust methodology can be developed.

Discoveries made with KCl-induced contractions have elucidated the more complex reactions involved in GPCRs signaling; once the mechanisms of smooth muscle Ca2+ sensitization and desensitization are fully understood, then the development of advanced treatments for vascular disorders such as hypertension, cerebral and coronary vasospasm, and vascular hyporeactivity following hemorrhagic shock may be possible. Studies have shown that KCl-induced contractions induce Ca2+-sensitization. Therefore, we tested the hypothesis that KCl induced Ca2+-sensitization is due to ROK activation by the increase in [Ca2+]i. To test this hypothesis, rabbit femoral arteries were permeabilized with 20µg/ml α-toxin and 1% Triton X-100 and subjected to different calcium concentrations in the presence or absence of various ROK inhibitors. For a comparison we also used various PKC and MLCK inhibitors and repeated these experiments in intact tissues. We found that either [Ca2+]i alone does not directly activate ROK or the permeabilization technique itself disrupts the normal ROK signaling system. Secondary findings revealed that α-toxin activates PKC pathways; in both chemically permeabilized preparations proteases also appear to be activated and MLCK is the primary kinase responsible for contraction.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T20:34:44Z No. of bitstreams: 1 CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-18T22:50:18Z (GMT) No. of bitstreams: 1 CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5) / Made available in DSpace on 2016-08-18T22:50:18Z (GMT). No. of bitstreams: 1 CynthiaKerziaCostaDeAraujo_DISSERT.pdf: 2646231 bytes, checksum: 4f582aa34d0b6a7e4961cbd1db1b17a2 (MD5) Previous issue date: 2016-03-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / ?No Brasil s?o gerados diversos tipos de subprodutos e res?duos agroindustriais como: baga?o de ped?nculo de caju, baga?o de cana-de-a??car, baga?o de coco e outros. A disposi??o final desses res?duos, ou seja, sua elimina??o causa s?rios problemas ambientais. Apesar de uma parte ser utilizada para fins diversos, uma grande quantidade ainda permanece sem utiliza??o. Neste sentido, os res?duos de conte?do lignocelul?sico, como a casca do coco verde, constituem uma mat?ria-prima renov?vel e abundante cujo aproveitamento ? desej?vel e tem provocado um interesse crescente para o uso na cadeia de produ??o de etanol de 2? gera??o. Neste trabalho foi utilizada como mat?ria-prima a casca de coco verde, a qual foi submetida a dois pr?-tratamentos com o objetivo de melhorar a acessibilidade das enzimas ? celulose. Os pr?-tratamentos aplicados ao baga?o de coco foram: ?cido/Alcalino utilizando H2SO4 0,6M e, em seguida, NaOH 1M e, o pr?-tratamento com Per?xido de Hidrog?nio Alcalino (PHA) a uma concentra??o de 7,35% (v/v) e pH 11,5. O objetivo principal do estudo em quest?o, foi avaliar a influ?ncia do biossurfactante (ramnolip?deo produzido pela Pseudomonas aeruginosa), durante a hidr?lise da casca de coco verde. Para efeito de compara??o, foram realizadas hidr?lises utilizando surfactante qu?mico, nesse caso o Triton X-100, e hidr?lises sem adi??o de surfactantes. Dessa forma, observou-se que, com a aplica??o de ambos os pr?-tratamentos, foi poss?vel atingir uma maior convers?o de celulose ao comparar com o material in natura. No entanto, ao analisar os resultados obtidos para o processo de hidr?lise com a aplica??o de surfactantes, verificou-se que o ramnolip?deo produzido melhora, consideravelmente, a convers?o celul?sica da casca de coco verde, atingindo uma convers?o de 33% ap?s 72 horas de hidr?lise, enquanto que, a convers?o m?xima atingida com o uso do Triton X-100 foi de 23%. Esses resultados mostram que o biossurfactante pode ser aplicado na hidr?lise enzim?tica de materiais lignocelul?sicos, de modo a apresentar uma boa influ?ncia no processo.? / In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip?d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neurocysticercosis (NC) caused by the Taenia solium metacestodes usually affects the central nervous system and can be confused with other brain pathologies, which present similar clinical and image findings. This parasitose is endemic in Brazil and the serological diagnosis of NC is of great importance in routine clinical management of patients. The search for alternative antigens for NC immunodiagnosis is importance because of the difficulty of obtaining parasites from naturally infected pigs for the preparation of metacestodes T. solium homologous antigen. Once that purified antigen is more sensitive and specific than crude saline extracts, the objective of this study was to evaluate the performance of enzyme linked immunosorbent assay (ELISA) and Immunoblotting (IB) for the serological diagnosis of human NC, using the crude saline extract (Crude) obtained from T. saginata metacestodes and two fractions of this extract, hydrophobic or detergent fraction (D) and hydrophilic or aqueous fraction (A), purified by extraction with Triton X-114 as alternative purified antigens for the diagnosis of human NC. Serum samples were obtained from 115 individuals: 40 patients with a definitive diagnosis of NC, 45 patients with Taenia sp. and with other parasitic diseases and 30 apparently healthy individuals. The serum samples were diluted 1:200 for ELISA but only the samples positives were diluted 1:100 and evaluated in IB. ELISA sensitivity and specificity were 95% and 73.3% when using Crude, 95% and 82.6% for D phase and 65% and 61.3% for A phase, respectively. The diagnostic efficiency and Youden index were: 83.9% and 0.74 (Crude), 88.5% and 0.80 (D phase) and 72.8 % and 0.46 (A phase), respectively. IB of the antigens confirmed the results obtained by ELISA, and the D phase antigen proved to be more specific than other extracts, showing only one immunodominant protein of 70-64 kDa that was the most frequent (92.5%) among patients with NC. Our results suggest that the D phase obtained with Triton X-114 can be used as heterologous purified antigen for the serological diagnosis of human NC in the IB. / A Neurocisticercose (NC), resultado do acometimento do sistema nervoso central pelas formas metacestódeas de Taenia solium, é uma doença polimórfica podendo ser confundida com outras síndromes neurológicas que apresentam achados clínicos e de imagem similares. Uma vez que esta parasitose é endêmica no Brasil o diagnóstico sorológico é de grande importância, pois auxilia na rotina laboratorial de pacientes com suspeita clínica. A busca por antígenos alternativos se faz necessária diante da dificuldade de obtenção de suínos naturalmente infectados com metacestódeos de T. solium, para a produção do antígeno homólogo. Uma vez que antígenos purificados apresentam sensibilidade e especificidade superiores aos extratos totais, o objetivo deste estudo foi avaliar os testes enzyme linked immunosorbent assay (ELISA) e Immunoblotting (IB) no diagnóstico sorológico da NC humana utilizando o extrato salino total (S) de metacestódeos de Taenia saginata e suas frações purificadas com Triton X-114 (TX-114). Uma alíquota do extrato S foi fracionada com TX-114, para obtenção das frações antigênicas: hidrofóbica ou detergente (D) e hidrofílica ou aquosa (A). Os extratos antigênicos foram analisados em SDS-PAGE 12% e utilizados no ELISA na concentração de 10μg/mL. Foram analisadas 115 amostras de soro: 40 de pacientes com diagnóstico definitivo de NC, 45 de pacientes com Taenia sp. e por outros parasitos e 30 de indivíduos saudáveis. As amostras foram diluídas a 1:200 para o ELISA, sendo apenas as positivas submetidas ao IB, na diluição de 1:100. A sensibilidade e especificidade do ELISA foram: 95% e 73,3% (S), 95% e 82,6% (D) e 65% e 61,3% (A), respectivamente. O cálculo de eficiência do diagnóstico e Youden Index foram: 83,9% e 0,74 (S); 88,5% e 0,80 (D) e 72,8 % e 0,46 (A), respectivamente. No IB a fração D apresentou com exclusividade a banda imunodominante de 70-64 kDa, sendo detectada em 92,5% dos pacientes com NC. A fração D foi significativamente mais eficiente que a fração A, tanto no ELISA quanto no IB, sendo assim, recomendada como antígeno heterólogo purificado no diagnóstico sorológico da NC humana no IB. / Mestre em Imunologia e Parasitologia Aplicadas

Surfactants from the 'Triton' range, manufactured by Rohm and Haas, Germany, were used to study the adsorptive behaviour of non-ionic surfactants (of the alkyl polyoxyethylene type) from aqueous solution onto mineral oxide surfaces. The oligomeric distributions of the surfactants were characterised using the HPLC technique. Two gradients were used: a normal phase gradient was used to study the surfactants from non-aqueous solution; an unusual gradient, which could not be definitively categorised as either normal or reversed phase and which was developed at Brunel, was used to analyse surfactants directly from aqueous solution. Quartz was used as a model mineral oxide surface. The quartz surface was characterised using a range of techniques: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, X-ray fluorescence -analysis, Fourier transform-infra red spectroscopy and BET analysis. It was found that washing the quartz with concentrated HCI removed any calcium ions present on the surface and also removed 02- ions. Calcining the sample removed carbonaceous materials from the surface and also caused a decrease in the surface area. The quartz was shown to be non-porous by SEM and BET analysis. The adsorption experiments for this study were carried out using a simple tumbling method for which known ratios of surfactant in aqueous solution and quartz silica were mixed together for a known length of time. The amounts of surfactant present were measured using ultra-violet analysis and the HPLC techniques mentioned above. It was found that the smallest oligomers were adsorbed the most. An addition of salt to the system caused an overall increase in adsorption of the bulk surfactant, and increase in temperature caused an initial decrease in adsorbed amounts before the plateau of the isotherm and a final increase in bulk adsorption at the plateau of the isotherm. The oligomeric adsorption generally appeared to mirror the behaviour of the bulk surfactant. Atomic force microscopy (AFM), dynamic light and neutron scattering studies were used to analyse the character of the adsorbed surfactant layer. It was shown that the layer reached a finite thickness that corresponded to a bilayer of adsorbed surfactant. According to AFM data, this value of thickness was not consistent over the whole of the quartz surface.

Este trabalho apresenta: 1) Duas revisões bibliográficas sendo uma sobre a síntese de α-ceto-tioésteres e -ésteres e a outra sobre a decomposição de sulfóxidos e sulfonas sulfeniladas; 2) Investigações prévias indicando a viabilidade da decomposição térmica e a estabilidade relativa dos derivados bissulfenilados de tioésteres de diferentes estados de oxidação Ia-e, obtidos a partir do α-ceto-tioéster; 3) O estudo de síntese de precursores de α-ceto-tioésteres II e α-ceto-ésteres III, a saber: α - metilsulfonil- α - metiltio tioésteres IVa-c, -éster V e α, α - dimetiltio - ésteres VIa-c; 4) Decomposição térmica de α-metilsulfonil-α-metiltio-tioésteres Iva, b e c e -éster V sintetizados aos α-ceto-tioésteres e ésteres correspondentes, pelo emprego do método elaborado anteriormente por Wladislaw e col. e sugestão do mecanismo da mesma. A síntese de α metilsulfonil α metiltio tiopropionato de etila (Ivb), foi efetuada a partir do ácido α-cloro propiônico através de quatro passos reacionais, a saber: sulfenilação por substituição, oxidação à sulfona , tioesterificação e sulfenilação pelo emprego de NaH/MeS02SMe em DMSO. A obtenção do α - benzil - α - metilsulfonil - α - metiltio - tioacetato de etila (Ivc) foi efetuada a partir de ácido α-cloro acético através de reações de sulfenilação por substituição oxidação à sulfona tioesterificação alquilação com brometo de benzila e NaH em DMSO e, finalmente, a sulfenilação que só foi possível com o emprego de N-metiltioftalimida. A síntese de α-metilsulfonil-α-metiltio-propionato de etila (V) foi efetuada a partir do α-metilsulfonil malonato VIIa pelo eemprego do método de descarbetoxilação sulfenilativa usando 1,4 diazabiciclo [2,2,2] octano (DABCO) em tolueno sob refluxo e MeSO2SMe. Os compostos VIIa,b e c foram preparados a partir dos malonatos de dietila alquil - substituidos, seguido de sulfenilação e oxidação à sulfona. É de interesse a inédita reação de α - metilsulfonil fenilmalonato de dietila (VIIb), com DABCO em benzeno sob refluxo e MeSO2SMe, que conduziu à dessulfonilação sulfenilativa fornecendo o α - metiltio - fenilmalonato de dietila. É apresentada uma discussão mecanística tanto sobre descarbetoxilação, como sobre dessulfonilação sulfenilativas. A síntese de α,α-dimetiltio-ésteres VIa-c foi efetuada pela reação de sulfenilação com descarboxilação dos mono-ácidos malônicos correspondentes. O acompanhamento da descarboxilação e experimentos de deuteração permitiram esclarecer a sequência dos passos reacionais nestas novas reações. Cabe ressaltar que são compostos ainda não descritos na literatura os precursores IVa, IVb, IVc, V e Vib e 11 intermediários envolvidos nas reações efetuadas. Os resultados apresentados neste trabalho, além de importância sintética, trazem uma contribuição para a Química de Compostos Orgânicos de Enxofre. / This work presents: 1) Two literature reviews, one about the synthesis of α-keto thioesters and esters and the other on the decomposition of sulfenylated sulfoxides and sulfones; 2) Previous investigations indicating the viability of thermal decomposition and the relative stability of the dithioderivatives of different oxidation states Ia-e,which were obtained from the α-keto thioester; 3) The study of synthesis of α-keto thioesters II and esters III precursors, which are the following: α-methylsulfonyl-α-methylthio-thioesters IVa-c and -ester V, and α, α - dimethylthio esters VIa-c; 4) Thermal decomposition of the synthesized α - methylsulfonyl- α -methylthio- thioesters Iva,b e c and ester V, to the corresponding α-keto thioesters and α-keto ester, through the method developed by Wladislaw et al., with the suggestion of the mechanism. α-Methylsulfonyl-α-methylthio ethyl thiopropionate (Ivb) was synthesized from α-chloro-propionic acid in four steps: sulfenylative substitution, oxidation to sulfone, thioesterification and sulfenylation using NaH/MeSO2SMe in DMSO. α-Benzyl-α-methylsulfonyl-α-methylthio ethyl thioacetate (,i>Ivc) was obtained from α-chloro acetic acid through the following steps: sulfenylative substitution, oxidation to sulfone, thioesterification, alkylation with benzylbromide and NaH in DMSO, and finally, the sulfenylation which was successful only with the use of N-methylthiophtalimide. α-Methylsulfonyl-α-methylthio ethyl propionate (V) was synthesized through the sulfenylative decarbethoxylation of α methylsulfonyl diethyl malonate VIIa employing DABCO (1,4-diazabicyclo [2.2.2.]octane), in refluxing toluene, and MeSO2Sme. The compounds VIIa,b e c were obtained by the alkylation of malonates, followed by sulfenylation and oxidation to sulfones. An interesting and novel reaction, the sulfenylative desulfonylation, was observed when α-methylsulfonyl phenyldiethyl malonate (VIIb) was treated with DABCO, in refluxing benzene and MeSO2SMe, which led to the α-methylthio diethyl malonate. A mechanistic discussion about the sulfenylative decarbethoxylation and sulfenylative desulfonylation is presented. α, α-dimethylthio esters VIa-c were synthesized by sulfenylation and decarboxylation of the corresponding malonic half-esters. The sequence of the steps of this new reaction could be determined by deuteration experiments and by following the evolution of CO2. The precursors IV, IVb, IVc, V e Vib and 11 intermediates were unknown compounds. This work, besides the synthetical importance, presents some contribution to the Organosulfur Chemistry.