Para elucidar os mecanismos envolvidos na inibição da hipersensibilidade do tipo I em proles murinas mediada pela imunização materna com Ovalbumina (OVA), as proles foram avaliadas quanto aos linfócitos Tγδ produtores de IL-17 (CD27-). A imunização materna com OVA reduziu a expressão de CD27, o que também se refletiu nos pulmões, e a produção de IL-17 por linfócitos Tγδ das proles. A redução da expressão de CD27 também foi evidenciada em linfócitos Tγδ intratímicos das proles após a transferência passiva de anticorpos IgG alérgeno específicos para fêmeas gestantes não imunizadas e in vitro em resposta a estes mesmos anticorpos, efeito que parece envolver a expressão de receptores para IgG expressos por outras células presentes no timo. As evidências obtidas indicam que a imunização materna influi na maturação tímica de linfócitos inibindo a população que colaborara com a inflamação alérgica. Aparentemente, os anticorpos IgG maternos são responsáveis por este fenômeno e a população estudada está envolvida na inibição da inflamação alérgica observada nas proles. / To elucidate the mechanisms involved in inhibition of type I hypersensitivity in murine offsprring mediated by maternal immunization with Ovalbumin (OVA), the offspring were evaluated as IL-17-producing γδT cells (CD27-). Maternal immunization with OVA reduced the expression of CD27, which was also reflected in the lungs, and the production of IL-17 by γδT cells of offspring. Reduction of CD27 expression was also evidenced in intrathymic γδT cells of offspring after passive transfer of allergen-specific IgG antibodies to non-immunized pregnant females and in vitro in response to these same antibodies, effect that seems to involve the expression of IgG receptors expressed by other cells present in the thymus. Evidence obtained indicates that maternal immunization influences the thymic maturation of lymphocytes by inhibiting the population that collaborate with allergic inflammation. Apparently, maternal IgG antibodies are responsible for this phenomenon and the population studied is involved in the inhibition of allergic inflammation observed in offspring.

No description available.

Magnetite (Fe3O4) thin films were prepared by a sol-gel process in which, a solution of iron (III) nitrate dissolved in ethylene glycol was applied on glass substrates by spin coating. Xerogel films were obtained by drying the coated films at 110 &deg / C. The films were sintered between 300 &deg / C and 450 &deg / C in order to observe the phases existing in the films at different temperatures. Coating solution showed Newtonian behaviour and viscosity was found as 0.0215 Pa.s. DTA analysis showed that, sintering temperature should be selected between 291 &deg / C and 350 &deg / C in order to produce magnetite thin films. Prepared magnetite thin films were characterized by XRD, SEM, AFM, TEM, VSM and UV-Vis spectrometer. In-plane grazing angle diffraction studies showed that magnetite phase was present upon sintering the films at 300 &deg / C. From the SEM studies, it was shown that films with defect free surfaces were obtained and by cross section studies, thickness of the films was found as ~10-200 nm. AFM images showed that no cracks or any other defects on the film surface were present. TEM results proved the existence of single phase magnetite in the produced films. UV-Vis spectrum results showed that transmittance of the films increases with decreasing sintering temperature and increasing spinning rate. Up to 96% transmittance was observed between the wavelengths of 900-1100 nm. Magnetic properties of magnetite thin films were also examined by VSM (Vibrating Sample Magnetometer) and ferromagnetic behaviour was shown using VSM data.

Albite (Na-feldspar) and orthoclase (K-feldspar) are the major feldspar minerals used in the production of glass and ceramics. They are found together with impurities like biotite, muscovite, quartz and rutile which are not desired for ceramics and glass industries. Therefore, these have to be removed to make the ore available for industrial use. In order to shed light on the actual feldspar ores, in this study / the flotation characteristics of albite, biotite, muscovite, orthoclase, quartz and rutile were investigated separately in their pure forms. In the investigation, the electrokinetic potential measurements and micro-flotation studies have been carried out to get information about their flotation characteristics under the effect of three different collectors, Aero 704, Aero 3000C and Aero 825, and the pH of the medium. The flotation recoveries were found to be pH dependent and the effective between the pH range of 7.0 and 11.5 in the presence of Aero 704. In the case of flotation with Aero 3000C, the recoveries reached up to 95.0% at certain concentrations and pH values and decreased sharply below pH 3.0 and above pH 9.5 for all the minerals tested. In the presence of Aero 825, the flotation recoveries of the minerals except for rutile, were found to be insufficient even with its highest concentration. In order to evaluate the adsorption mechanism of the collectors, Atomic Force Microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR) analyses were carried out. From the AFM results it might be deduced that the behavior of Aero 3000C and Aero 825 was found to be almost similar for biotite and muscovite as monolayer adsorption and for the remaining minerals, albite, orthoclase, quartz and rutile, as monolayer and bilayer adsorption together. In the case of Aero 704, for albite and orthoclase, the adsorption of the collector might be the reason for monolayer and bilayer formation on their surfaces. The strength of the interaction of the collectors on the mineral surfaces was followed by FTIR analyses before and after acetone washing. The interaction of all the collectors was found to be weak in the case of albite, orthoclase, quartz and rutile whereas the interaction of Aero 704 and Aero 3000C was found to be strong in the case of biotite and muscovite.

The aim of this study is to investigate the deterioration in mechanical integrity of the collagen network in bovine bone with aging, which are related to fracture toughness. Age-related changes in collagen molecular structures formed by non-enzymatic glycation were examined and indentation fracture technique was used as a method for measuring the microstructural toughness of cortical bone. Microcrack propagation characteristics of bone for fragility were also studied. Young and old group of bovine cortical bone specimens were grouped into 2 as ribosylated and non-ribosylated which were rested in solutions for four weeks. Series of indentations were made on bone specimen groups for each of five masses 10g, 25g, 50g, 100g and 200g for 10 sec to detect the effect of applied indentation load. The applied load was increased to 300g, 500g, 1000g and 2000g for 10 sec to be able to make microcracks. Series of indentations were made on bone specimen groups for each of five durations 5sec, 10sec, 20sec, 30sec for 100g to study the effect of indentation duration. Specimens were examined in the wet and dry state while studying the factors effecting microhardness measurement. Microhardness values measured by 10g of load for 10sec were indifferent between the ribosylated and non-ribosylated groups in the young and old bovine bone pointing that this load is not indicative of the structural collagen changes. Loads of 25g, 50g, 100g and 200g for 10 sec were able to differ ribosylated bone from non-ribosylated bone for the young and old bovine bones. Degree of microhardness increased with increased incubation period. Microhardness of dry specimens being either ribosylated or non-ribosylated were found to be statistically higher than wet specimens in young and old bone except for 10g for 10sec. It has been shown that the calculated fracture toughness measured by the indentation method is a function of indentation load. Additionally, effect of indentation size might have resulted in a higher toughness measurement for higher indent loads with longer cracks even if the toughness is not actually higher.Methods using indentation technique has difficulty in relating the resistance to crack growth to the Mode I fracture toughness definition.Indentation fracture toughness allows sampling only one point on the R&shy / curve methods and was not considered as successful for assessing materials with rising R&shy / curve. Toughness is ranked incorrectly among riboslated and non-ribosylated bovine bone by this technique. Presence of extrinsic toughening mechanisms including crack bridging due to uncracked ligaments and collagen fibers were directly observed by scanning electron microscope. Ribosylated bone was found to have lower number of collagen bridging compared ton on-ribosylated bovine bone.As a summary, indentation fracture method by Vickers indentation in bone is a method for measuring the fracture toughness.

The influence of drying parameters namely residence time before drying, drying temperature, drying time, relative humidity, and slip recipe on the drying rate of slip cast sanitary wares, predominantly lavatories and toilet closets, was studied. The drying temperatures were changed from 80 oC to 110 oC with an increment of 10 oC. The drying time was changed from 10 to 7 h with a decrease of 1 hour. Relative humidity of the environment was changed from 60 to 75 %. The percent weight loss, percent residual moisture and the percent shrinkage of the samples were determined by weighing and measuring the samples before and after the tests. The percent weight loss was within the range of 6.5 to 6.6 % after holding the as cast samples for 6 hours at ambient casting shop conditions while it was within the range of 17.96 to 18.10 % when subsequently dried for 10 hours at 110 oC in the dryer. The percent shrinkage was within the range of 2.9 - 3.0 % after holding the as cast samples 6 h at ambient laboratory conditions. No shrinkage was observed in the sample when it was subsequently dried for 10 hours at 110 oC in the dryer. Optimum moisture content of dried wares was obtained after drying for 8 hours at 100 oC in the dryer. It has been seen that the relative humidity of the dryer at the beginning of the drying should be lower than 75 %. As the non-plastic content in the recipe of the sanitary ware slip increased, drying shrinkage and residual moisture content decreased. The results of this study showed that through increasing the residence time up to 6h with a casting shop environment of approximately 30 oC and 60 % relative humidity, the drying time could be safely reduced from 10 h to 8 h with a drying temperature of 100 oC for the test plates. The same approach can be used for more complex shapes, e.g., WC closets, basins, tanks etc. in EczacibaSi Vitra plant. Once the drying time was reduced, the amount of natural gas per ware would be reduced to a certain extent. Aside from that the reduction in the drying time would increase the quantity of the drying cycles per week so that more wares could be dried. When all these observations were taken into account, this thesis study could also be utilized by other sanitary ware producing companies whose processes require slip cast drying.

Made available in DSpace on 2016-06-02T20:16:55Z (GMT). No. of bitstreams: 1 DissJSN.pdf: 1921284 bytes, checksum: 5da39ba2b3c3edf4d1bfd30cd4d33b69 (MD5) Previous issue date: 2005-03-10 / In this work we have studied the interaction of Vortex Matter with columnar defects in YBa2Cu3O7- δ supercondutcting samples. In these samples prepared by a Solgel chemical route, the granularety is delicately controled so that the the average cross section of grains is reasonably constant and the penetration of magnetic flux lines is columnar-like. Using magnetic and transport measurements we have constructed the phase diagram of the studied sample, determinating the higher critical field, the irrevesibility line, and the line were the pinned vortices lose longitudinal coherence which we call H*(T). AC-susceptibility and 6-terminal transport measurements were used to determine H*(T). The results confirm that, above T* there is a break of longitudinal coherence and the vortices behave like "pancakes" according to Clem's model, whereas below T* the longitudinal coherence is maintained. The experimental line H*(T) was theoretically ajusted, confirming that it is a line of change from the three-dimensional coherence of the vortices, to an almost two-dimensional of the "pancakes". Due the existence of a variety of superconducting systems with columnar-like defects that also present the line H*(T), as for example Mg-deficient MgB2, it is useful to compare them with the hope that some type of universal behavior can be observed. The normalized magnetic phase diagram with data of YBa2Cu3O7- δ and MgB2 revealed the expected similarity between the two systems studied, due to microstructural similarities between both and not to any intrinsic characteristic of the superconducting materials, that are very different among themselves. / Neste trabalho estudamos a interação da Matéria de Vórtices com defeitos colunares em amostras supercondutoras de YBa2Cu3O7- δ. Nestas amostras, preparadas por rota química Sol-gel, a granularidade é delicadamente controlada de forma que a secção reta média dos grãos é razoavelmente constante, e a penetração das linhas de fluxo magnético tenha aspecto colunar. Através de medidas magnéticas e de transporte elétrico, construímos o diagrama de fases magnéticas da amostra estudada, determinando campo crítico superior, linha de irreversibilidade, e linha em que os vórtices alojados nas colunas intergranulares perdem coerência longitudinal, à qual chamamos de H*(T). Medidas de suscetibilidade magnética-AC e de resistência elétrica através da técnica de 6 terminais, permitiram a determinação de H*(T). Os resultados confirmam que acima de T* há uma quebra de coerência e os vórtices se comportam como panquecas , segundo o modelo de Clem, e abaixo de T*, a respeito do movimento viscoso, a coerência longitudinal é mantida. A linha experimental H*(T) também foi ajustada teoricamente, confirmando que se trata de uma linha de mudança de coerência tridimensional dos vórtices, para quase bi-dimensional das panquecas . Devido à existência de diversos sistemas supercondutores com defeitos de aspecto colunar que também apresentam a linha H*(T), como por exemplo o MgB2 deficiente em Mg, cujos resultados motivaram este trabalho, é útil compará-los na expectativa de observar algum tipo de comportamento universal. Assim, normalizamos o diagrama de fases magnético com dados de YBa2Cu3O7- δ e de MgB2, e pudemos constatar que realmente há uma grande semelhança entre os dois sistemas estudados, o que se deve às similaridades microestruturais entre ambos, mas não à qualquer característica intrínseca dos materiais supercondutores, que são muito diferentes entre si.

No description available.

Neste trabalho, o gene da α-amilase de Bacillus subtilis foi clonado em S. cerevisiae, por δ-integração. Foram construídos dois vetores: 1) o gene truncado da α-amilase de B. subtilis (amyEt) com a sequência sinal própria, sob regulação do promotor e terminador ADH1 (δAmyEtδ); 2) o gene da α-amilase completo de B. subtilis (amyE), com a sequência sinal MFα de S. cerevisiae, sob a regulação do promotor e terminador PGK (δAmyEδ). Esses vetores foram empregados na transformação genética de linhagens S. cerevisiae, em co-transformação com o plasmídeo pAJ50, que permite a seleção positiva. Os clones transformantes cultivados em meio YPDA (0,5% amido) produziram halos de amilolise de diferentes tamanhos. Os que receberam o gene da α-amilase completo sob a regulação de PGK (δAmyEδ) apresentaram os melhores resultados para a hidrólise de amido. Nenhum clone teve o crescimento prejudicado em relação à linhagem controle selvagem. Estes resultados indicam que os novos vetores apresentam bom potencial para emprego na construção de linhagens industriais de S. cerevisiae. / At the present work, the α-amylase gene from Bacillus subtilis was cloned in S. cerevisiae by δ-integration. We constructed two vectors: 1) a truncated α-amylase gene of B. subtilis (amyEt) with its own signal sequence, under the regulation of the ADH1 promoter and terminator of S. cerevisiae (δAmyEtδ), 2) a complete α-amylase gene of B. subtilis (amyE), with the signal sequence of MFα of S. cerevisiae under the regulation of PGK promoter and terminator (δAmyEδ). These vectors were used to genetic transformation in S. cerevisiae strains, in co-transformation with pAJ50 plasmid , which allows positive selection. The transformant clones grown in YPDA (0.5% starch) produced amilolise halos of different sizes. Those which received the complete -amylase gene under the regulation of PGK (δAmyEδ) showed the best results for starch hydrolysis. None of the clones had its growth capacity altered when compared to the wild type. These results indicate that these vectors have a good potential to be employed in industrial strains transformation of S. cerevisiae.

Neste trabalho, o gene da α-amilase de Bacillus subtilis foi clonado em S. cerevisiae, por δ-integração. Foram construídos dois vetores: 1) o gene truncado da α-amilase de B. subtilis (amyEt) com a sequência sinal própria, sob regulação do promotor e terminador ADH1 (δAmyEtδ); 2) o gene da α-amilase completo de B. subtilis (amyE), com a sequência sinal MFα de S. cerevisiae, sob a regulação do promotor e terminador PGK (δAmyEδ). Esses vetores foram empregados na transformação genética de linhagens S. cerevisiae, em co-transformação com o plasmídeo pAJ50, que permite a seleção positiva. Os clones transformantes cultivados em meio YPDA (0,5% amido) produziram halos de amilolise de diferentes tamanhos. Os que receberam o gene da α-amilase completo sob a regulação de PGK (δAmyEδ) apresentaram os melhores resultados para a hidrólise de amido. Nenhum clone teve o crescimento prejudicado em relação à linhagem controle selvagem. Estes resultados indicam que os novos vetores apresentam bom potencial para emprego na construção de linhagens industriais de S. cerevisiae. / At the present work, the α-amylase gene from Bacillus subtilis was cloned in S. cerevisiae by δ-integration. We constructed two vectors: 1) a truncated α-amylase gene of B. subtilis (amyEt) with its own signal sequence, under the regulation of the ADH1 promoter and terminator of S. cerevisiae (δAmyEtδ), 2) a complete α-amylase gene of B. subtilis (amyE), with the signal sequence of MFα of S. cerevisiae under the regulation of PGK promoter and terminator (δAmyEδ). These vectors were used to genetic transformation in S. cerevisiae strains, in co-transformation with pAJ50 plasmid , which allows positive selection. The transformant clones grown in YPDA (0.5% starch) produced amilolise halos of different sizes. Those which received the complete -amylase gene under the regulation of PGK (δAmyEδ) showed the best results for starch hydrolysis. None of the clones had its growth capacity altered when compared to the wild type. These results indicate that these vectors have a good potential to be employed in industrial strains transformation of S. cerevisiae.