This study was developed to examine the performance, carcass and cut yields, nutrient digestibility, and intestinal histomorphometry of chickens fed diets supplemented with protected sodium butyrate until 21 days of age. Two experiments were conducted, both of which involved the following treatments: basal diet with inclusion of an antibiotic; basal diet without antibiotic or protected sodium butyrate (PSB; control); basal diet with inclusion of 225 g/t PSB in the pre-starter and starter phases; and basal diet with inclusion of 300 g/t PSB in the pre-starter and starter phases. In the first experiment, 784 male broiler chicks were distributed into the four treatments, with seven replicates of 28 birds, to evaluate performance and carcass and cut yields. In experiment II, 280 male broiler chicks were distributed into the four treatments, with seven replicates of 10 birds, to evaluate intestinal digestibility and histomorphometry. At 42 days of age, the broilers supplemented with 225 g/t PSB had a higher average final weight than the control group. At seven days, the chickens supplemented with 300 g/t PSB exhibited the highest duodenal villus height; those supplemented with 225 or 300g/t PSB or antibiotic showed the greatest jejunal villus height; and those treated with 225 g/t PSB exhibited the highest jejunal villus/crypt ratio. At 21 days of age, the broilers that received 225 g/t PSB showed the highest duodenal and jejunal villus height. The use of protected sodium butyrate in chicken diets up to 21 days of age improves intestinal development and performance until slaughter age.

Measurements of the electric current as a function of time during the electrochemical deposition of metals are usually treated considering models based on the Kolmogorov- Avrami theory or alternatives to it including hierarchical overlap of diffusion zones. These models explain the main tendencies of the nucleation and growth of the metallic deposits but still do not include details related to the anomalous deposition of metallic alloys, although the electrochemical methods are widely used for their production. In this work, a discussion of the several factors involved in this issue is presented to evidence the need for a more comprehensive model that may reach a complete quantitative description of electrodeposition of alloys including the anomalous phenomenon. Cyclic voltammetry as well as chronoamperometry measurements in a sulfate solution for Ni-Fe deposition were used to exemplify several aspects to be better understood and included in the model. Some Ni-Fe films were also deposited and characterized by scanning electron microscopy and ferromagnetic resonance to discuss some additional aspects as final composition and structure.

ResumoO óxido de estanho (SnO2) é um material promissor com grande potencialidade para aplicações como sensores de gás e catalisadores. Nanoestruturas deste óxido apresentam maior eficiência de ativação devido a sua maior superfície efetiva. O presente trabalho apresenta resultados da síntese e caracterização do óxido de estanho em diferentes condições, via oxidação do estanho sólido com ácido nítrico. Resultados obtidos com a caracterização do pó de SnO2 principalmente por difração de raios X e microscopia eletrônica de varredura, além de técnicas auxiliares como a espectroscopia por dispersão de energia, espalhamento de luz dinâmico e espectroscopia de infravermelho, indicaram que as condições estabelecidas para a síntese foram adequadas para a obtenção de grânulos nanométricos de óxido de estanho com estrutura cristalina tetragonal do tipo rutilo.

AbstractTin dioxide (SnO2) is a promising material with great potential for applications such as gas sensors and catalysts. Nanostructures of this oxide exhibit greater activation efficiency given their larger effective surface. The present study presents results of the synthesis and characterization of tin dioxide under different conditions via oxidation of solid tin with nitric oxide. SnO2powder was characterized primarily by X-ray diffraction and scanning electron microscopy, as well as complementary techniques such as energy-dispersive X-ray spectroscopy, dynamic light scattering and Fourier transform infrared spectroscopy. The results indicated that the established synthesis conditions were suitable for obtaining rutile tin dioxide nanoparticles with a tetragonal crystal structure.

Em células a combustível1 de eletrólito polimérico sólido o principal componente é o conjunto membrana/eletrodos - MEA (membrane-eletrocde assembly). Os eletrodos de difusão de gás - GDL (gas diffusion layer) são um dos principais constituintes do MEA, sendo um material compósito constituído de camadas difusora e catalítica, formadas por pó de carbono, platina e polímeros - PTFE (politetrafluoretileno) e Nafion - depositados sobre um substrato (papel ou tecido de carbono). Essas camadas apresentam superfícies rugosas e porosas, de caracterização complexa. O objetivo deste trabalho é caracterizar a GDL. A molhabilidade da superfície foi determinada por medidas de ângulo de contato externo pelo método da gota de água. Os ângulos de avanço e recuo foram medidos e usados para estimar a histerese e o ângulo de equilíbrio. A morfologia e a composição foram estudadas usando Microscopia eletrônica de varredura e espectroscopia de energia dispersiva, enquanto que a porosidade foi medida embebendo os substratos com n-heptano e água para quantificar os poros hidrofílicos/hidrofóbicos. O estudo morfológico indicou que a incorporação do PTFE no pó de carbono é uma etapa crítica na fabricação das camadas difusoras. Uma maior quantidade de PTFE resulta no decréscimo da porosidade total e um aumento do percentual de poros hidrofóbicos para ambos os substratos. Os resultados obtidos na determinação dos ângulos de contato apresentaram boa precisão, em especial para os compósitos depositados sobre o tecido de carbono. Os ângulos de contato obtidos para as camadas catalíticas foram inferiores aos das camadas difusoras, provavelmente devido à presença do Nafion, que apresenta caráter hidrofílico minimizado a hidrofobicidade do compósito. Esses resultados confirmaram a complexidade do GDL e a importância de sua caracterização detalhada para a otimização da fabricação do MEA.

In polymer electrode fuel cells the main component is the membrane/electrodes assembly (MEA). Gas diffusion electrodes (GDL) are the principal components of the MEA, being a composite material constituted of diffusion and catalyst layers, formed by carbon powder, platinum, PTFE and Nafion polymers deposed over a subtract (carbon paper or cloth). These layers present roughness and porous surfaces of complex characterization. The aim of this work is to characterize GDL. The surface wettability was assessed by drop water external contact angle measurements. The advancing and receding angles were measured and used to estimate the hysteresis and the equilibrium angle. Morphology and composition were studied using scanning electronic microscopy and energy dispersive spectroscopy while porosity was measured by imbibing n-heptane and water into substrates to quantify hydrophilic/hydrofobic pores. Morphologic study indicated that PTFE incorporation into carbon power is a critical step on diffusion layers fabrication. A greater amount of PTFE results in decrease the total porosity and increases the percent of hydrophobic porous for both substrates. The results obtained in angles contact determination present good precision, especially for the composite deposited over carbon cloth. The values obtained for contact angels of the catalyst layers were lower than ones measured over diffusion layer, probably due to the presence of Nafion, which presents a hydrophilic character minimizing the composite hydrophobicity. These results confirmed the complexity of GDL and confirmed the importance of a detailed characterization for MEA assembly optimization.

RESUMO A mastite é considerada uma doença que causa grandes prejuízos econômicos, reduzindo em quantidade e qualidade o leite e os derivados lácteos. As opções de tratamento de vacas com mastite clínica são o uso de antimicrobianos em todas as vacas, o tratamento de nenhuma delas com antimicrobianos, apenas casos específicos com antimicrobianos ou tratamentos com medicamentos homeopáticos. Animais que respondem aos tratamentos sem uso de medicamentos, têm uma predisposição a recuperar-se do quadro clínico de mastite, mesmo na presença de agente infeccioso. Neste trabalho foi feita uma inoculação intramamária experimental com Staphylococcus aureus, e a partir do surgimento dos sinais clínicos instituiu-se o tratamento apenas com ordenhas múltiplas. Os animais foram avaliados através de escores clínicos, contagem de células somáticas (CCS), California Mastitis Test (CMT) e exames microbiológicos. Como alguns animais não responderam a esse tratamento, foram utilizados medicamentos homeopáticos ou antibiótico para os tratamentos e posteriormente comparados com o tratamento feito apenas com ordenhas múltiplas. Para os animais que puderam ser tratados com ordenhas múltiplas, os escores clínicos e de CMT foram estatisticamente menores (p < 0,05) quando comparados com aqueles tratados com antibiótico e medicamentos homeopáticos e estes dois não apresentaram diferença na eficiência, apresentando cura clínica no 9º dia pós-inoculação.

ABSTRACT Mastitis is considered an illness that causes great losses in milk production, reducing the quantity and quality of milk and dairy products. The options for treatments in cows with clinical mastitis are the usage of antimicrobials in all the animals, the treatment of none of them with antimicrobials, just some of them, or with homeopathic medicines. Animals that respond to no medical treatments have a predisposition to recover from clinical mastitis, even in the presence of the infectious agent. This began with an experimental intramammary inoculation with Staphylococcus aureus and after the beginning of the clinical signs there was established a treatment only by milking-out the cows. The animals where evaluated by clinical scores, somatic cell counts (SCC), California Mastitis Test (CMT) and microbiological parameters. As some animals did not respond to this treatment, they where treated with homeopathic medicines or antibiotics, afterward the results were compared with the milking-out treatment. For the animals that were possible to be treated by milking-out, the clinic and CMT scores were statistically smaller (p < 0.05) when compared with those treated with antibiotices and homeopathic medicines and for these two treatments there was no difference in the efficiency, exhibiting clinical cure at the 9th daypost-inoculation.

Main parameters of InGaAs/InAlAs multiple quantum well amplitude modulators, such as contrast ratio, insertion loss and chirp parameter, were calculated in order to find a quantum well structure which optimizes them. The parameters were estimated from the theoretical absorption curves, which were calculated for different values of applied reverse bias and were compared with experimental data. A study of the device parameters as a function of the Ga content and operation voltage was performed. The study showed that optimum values for the modulator parameters cannot be obtained simultaneously. The influence of the residual doping level and the applied pre-bias are emphasized.

GaAs/AlGaAs multiple quantum well structures containing an nipi delta-doping superlattice, where the n-type doping is inserted in the quantum wells and the p-type in the barriers, have been studied in detail to evaluate their potential for use in the fabrication of amplitude modulators. It is shown that C is an adequate p-type dopant for such structures, however, little exibility is found in the growth conditions, in particular for the V to III uxes ratio, for obtaining such layers. It is also observed that the required balance between n and p type doping levels is not trivial to be achieved due to the presence of interface hole traps whose population depends on the quantum well doping concentration. In addition, the observed photoluminescence near-edge emission at room temperature occurs at essentially the same energy as that of an equivalent undoped structure. Finally, no deep level emissions are observed which could deteriorate the device performance.

Pilocarpine is a cholinergic agonist that increases salivary flow and has been used to treat xerostomia. Oral intake is the most frequent route of administration. Adverse effects are dose-dependent and include sudoresis, facial blushing and increased urinary frequency. The objective of the present study was to evaluate the effects of topical pilocarpine solutions as mouthwashes on salivary flow and their adverse effects on healthy subjects. Forty volunteers received 10 ml 0.5, 1 and 2% pilocarpine solutions or 0.9% saline in a randomized, double-blind, placebo-controlled manner. Salivation was measured before and 45, 60 and 75 min after mouth rinsing for 1 min with 10 ml of saline or pilocarpine solutions. Vital signs were measured and ocular, gastrointestinal and cardiovascular symptoms, anxiety and flushing were estimated using visual analog scales. There was a dose-dependent increase in salivation. Salivation measured after 1 and 2% pilocarpine (1.4 ± 0.36 and 2.22 ± 0.42 g, respectively) was significantly (P<0.001) higher than before (0.70 ± 0.15 and 0.64 ± 0.1 g), with a plateau between 45 and 75 min. Cardiovascular, visual, gastrointestinal and behavioral symptoms and signs were not changed by topical pilocarpine. Mouth rinsing with pilocarpine solutions at concentrations of 1 to 2% induced a significant objective and subjective dose-dependent increase in salivary flow, similar to the results reported by others studying the effect of oral 5 mg pilocarpine. The present study revealed the efficacy of pilocarpine mouthwash solutions in increasing salivary flow in healthy volunteers, with no adverse effects. Additional studies on patients with xerostomia are needed.

Chronic urticaria and concurrent angioedema are disappoiting problems for both physicians and patients. The disease can result from multiple causes and probably does not have a single etiology. Several factors have been identified that appear to be important in the pathogenesis of individual cases, some drugs, food additives, physical factors and internal diseases. In some cases no pathogenesis are identified and those cases are classified as idiopathic. In recent years several articles has emphasized autoimmunity and infections due to Helicobacter pylori. Our article reviewed the etiology of chronic urticaria at current concepts.