896 resultados para Patterend Wall Surfaces
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Use of antibiotics as an additive in poultry diets to improve growth has been discussed in relation to bacterial resistance and the development of new products and management practices. This study was carried out to test the efficacy of a new substance (Saccharomyces cereviside cell walls, var. Calsberg- SCCW) obtained from the brewery industry, added (at 0.1 and 0.2%) to broiler chicken diets (based on corn and soybean meal), on performance and intestinal mucosa development. In Experiment 1 (carried out in litter-floor pens) the results revealed higher body weight gain,for the total experimental period and higher villus height at 7 d of age for the birds fed 0.2%,SCCW. In a field test using 44,000 broilers that,received feed containing 0.2% SCCW,. The results also showed higher body weight gain and better feed conversion for SCCW-supplemented birds. The present findings show that SCCW improved body weight gain in broiler chickens and that this effect can be attributed to the trophic effect of this product on the intestinal mucosa, because it increases villus height, particularly during the first 7. d of a chicken's life.
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This study was carried out to verify if Saccharomyces cerevisiae cell wall (SCCW) dietary supplementation (0.2%) was capable of protecting the intestinal mucosa of broiler chickens vaccinated against coccidiosis. Body weight gain, feed intake, feed conversion and intestinal mucosa morphometric parameters and epithelial loss were evaluated. In the experiment,400 day-old male chicks were distributed according to a completely randomized design in a 2x2 factorial arrangement. The following treatments were applied: T1 - no vaccination/ no SCCW supplementation; T2 - no vaccination/SCCW supplementation; T3 - vaccination/no SCCW supplementation; and T4 - vaccination/SCCW supplementation to four replicates of 25 birds each. Birds were vaccinated on the first day of age using a spray vaccine (Coccivac B®, Coopers), containing E. acervulina, E. maxima, E. mivati and E. tenella. S. cerevisiae cell wall was supplied from the first day of age. Live performance, intestinal morphometric parameters and epithelial loss were evaluated at 14, 21 and 28 days of age. Performance was affected by vaccination only at 21-days of age, when body weight gain was reduced in the vaccinated birds, but no body weight difference was observed on day 28. Vaccine also increased the crypt depth (p<0.05) in the duodenum and jejunum, suggesting a high cell activity in the crypt:villus transition area to maintain the epithelial cell turnover. Villi number/area (103,269 µm²) was not affected (p>0.05) by vaccine or cell wall supplementation, and epithelial loss was more pronounced in the duodenum and jejunum. In conclusion, the findings of this study suggest that S. cerevisiae cell wall supplementation may be an useful management tool to maintain the intestinal integrity of broilers vaccinated against coccidiosis.
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This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.
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O conceito de superfície geomórfica permite uma interligação entre os diferentes ramos da ciência do solo, tais como geologia, geomorfologia e pedologia. Esta associação favorece a compreensão da distribuição espacial dos solos na paisagem, e torna possível compreender o comportamento dos atributos do solo, que estão principalmente relacionadas com a estratigrafia e formas do relevo. Assim, este estudo visa à aplicação da estatística multivariada para categorizar superfícies geomórficas em uma litossequência arenito-basalto, de modo a fornecer uma base para a avaliação do solo em áreas afins. A área de estudo está localizada no município de Pereira Barreto, São Paulo, Brasil. A área escolhida possui 530 hectares, onde foram localizadas e mapeadas três superfícies geomórficas (I, II e III). Na área, 134 amostras foram coletadas nas profundidades de 0,0-0,2 m e 0,8-1,0 m, foram determinados os conteúdos de areia, silte e argila, pH em CaCl2, conteúdo de MO, P, Ca, Mg, K, Al e H+Al. Com base nos resultados, foram realizadas a análise univariada e multivariada de variância, clusters e principal componente, a fim de comparar as três superfícies geomórficas. A análise estatística univariada dos atributos do solo não foi eficiente na identificação das três superfícies geomórficas. Utilizando-se os atributos físicos e químicos do solo, as técnicas estatísticas multivariada permitiram à separação dos três grupos de corpos naturais do solo que foram equivalentes as três superfícies geomórficas mapeadas. Estes resultados são interessantes, pois demonstram a viabilidade da utilização de classificação numérica das superfícies geomórficas para ajudar no mapeamento de solo.
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Avaliou-se a evolução anual das componentes global, direta e difusa da radiação solar incidente em superfícies inclinadas a 12,85; 22,85 e 32,85º, com face voltada ao Norte, em Botucatu-SP. Foram obtidas frações radiométricas para cada componente da radiação nas superfícies supracitadas, através de razões com a radiação global e a do topo da atmosfera. A sazonalidade foi avaliada através das médias mensais dos valores diários. As medidas ocorreram entre 04/1998 e 07/2001, em 22,85º; 08/2001 e 02/2003, em 12,85º; e de 03/2003 a 12/2007, em 32,85º, com medidas concomitantes no plano horizontal (referência). Os níveis das radiações global e direta nos planos inclinados foram inferiores no período de verão e superiores entre os equinócios, quando comparadas ao plano horizontal. A radiação difusa nas superfícies inclinadas foi inferior na maioria dos meses, com perdas de até 65%. Ocorreu uma tendência de aumento das diferenças entre as superfícies horizontal e inclinada com o incremento do ângulo em todas as componentes e frações da radiação incidente. A evolução anual das precipitações pluviométricas e da razão de nebulosidade afetou diretamente a transmissividade atmosférica das componentes direta e difusa na região.
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In the execution of civil engineering works, either by wasting during the coating of wall or demolition of gypsum walls, the generation of the gypsum waste involves serious environmental concerns. These concerns are increased by the high demand of this raw material in the sector and by the difficulties of proper disposal byproduct generated. In the search for alternatives to minimize this problem, many research works are being conducted, giving emphasis in using gypsum waste as fillers in composites materials in order to improve the acoustic, thermal and mechanical performances. Through empirical testing, it was observed that the crystallization water contained in the residue (CaSO4.2H2O) could act like primary agent in the expanding of the polyurethane foam. Considering that polyurethane produced from vegetable oils are biodegradable synthetic polymers and that are admittedly to represent an alternative to petrochemical synthetic polyurethane, this research consist an analysis of the thermal behavior of a composite whose matrix obtained from a resin derived from the expansive castor oil seed, with loads of 4%, 8%, 12% and 16% of gypsum waste replacing to the polyol prepolymer blend. Contributors to this analysis: a characterization of the raw material through analysis of spectroscopy by Fourier transform infrared (FTIR), chemical analysis by X-Ray Fluorescence (XRF) and mineralogical analysis by X Ray Diffraction (XRD), complemented by thermo gravimetric analysis (TGA). In order to evaluate the thermo physical properties and thermal behavior of the composites manufactured in die closed with expansion contained, were also carried tests to determine the percentage of open pore volume using a gas pycnometer, scanning electronic microscopy (SEM), in addition to testing of flammability and the resistance to contact with hot surfaces. Through the analysis of the results, it appears that it is possible to produce a new material, which few changes in their thermo physical properties and thermal performance, promotes significant changes and attractive to the environment
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The use of reflective surfaces functioning as thermal insulator has grown significantly over the years. Reflective thermal insulator are materials that have several characteristics such as low emissivity, low absorptivity and high reflectivity in the infrared spectrum. The use of these materials has grown a lot lately, since it contains several important radioactive properties that minimize the heat loss of thermal systems and cooling systems that are used to block the heat on the roof of buildings. A system made of three surfaces of 316 stainless steel mirror was built to analyze the influence of reflective surfaces as a way to reduce the heat loss and thereby conserve the energy of a thermal system. The system was analyzed both with and without the presence of vacuum, and then compared with a system that contained glass wool between the stainless steel mirror walls, since this isolator is considered resistive and also broadly used around the world in thermal systems. The reflectivity and emissivity of the surfaces used were also measured in this experiment. A type K thermocouple was fixed on the wall of the system to obtain the temperature of the stainless steel mirror surfaces and to analyze the thermal behavior of each configuration used. The results showed an efficiency of 13% when the reflective surfaces were used to minimize the heat loss of the thermal system. However, the system with vacuum had the best outcome, a 60% efficiency. Both of these were compared to the system made of glass wool as a thermal insulator
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Space Science was built using a composite made of plaster, EPS, shredded tires, cement and water. Studies were conducted to thermal and mechanical resistance. Inside the mold EPS plates were placed in order to obtain a higher thermal resistance on the wall constructed, as well as to give it an end environmentally friendly in view of both the tire and the EPS occupy a large space in landfills and year need to be degraded when released into the environment. Compression tests were performed according to ABNT blocks to seal, measurements of the temperature variation in the external and internal walls using a laser thermometer and check the temperature of the indoor environment using a thermocouple attached to a digital thermometer. The experiments demonstrated the heat provided by the composite values from the temperature difference between the internal and external surfaces on the walls, reaching levels of 12.4 ° C and room temperature in the interior space of the Science of 33.3 ° C, remaining within the zone thermal comfort for hot climate countries. It was also demonstrated the proper mechanical strength of such a composite for sealing walls. The proposed use of the composite can contribute to reducing the extreme housing shortage in our country, producing popular homes at low cost and with little time to work
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The thermal degradation behaviour of rubber from six new Hevea brasiliensis clones (IAC 40, 56, 300, 301, 302 and 303) from São Paulo State, Brazil was studied by thermogravimetry using the Flynn-Wall-Ozawa approach to assess the kinetic parameters ( reaction order, activation energy and pre-exponential factor) of the decomposition process. This study indicated that the thermal behaviour is a complex multiple step process, which depends on the type of rubber Hevea clones studied. The rubber from these clones can be classified, following the order of decreasing thermal stability, as IAC 303 > 302 > 56 > 40 > 300 > 301.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of the most frequent systemic mycosis in Latin America. In humans, infection starts by inhalation of fungal propagules, which reach the pulmonary epithelium and differentiate into the yeast parasitic phase. Here we describe the characterization of a Dfg5p ((d) under bar efective for (f) under bar ilamentous (g) under bar rowth) homologue of P. brasiliensis, a predictable cell wall protein, first identified in Saccharomyces cerevisiae. The protein, the cDNA and genomic sequences were analysed. The cloned cDNA was expressed in Escherichia coli and the purified rPbDfg5p was used to obtain polyclonal antibodies. Immunoelectron microscopy and biochemical studies demonstrated the presence of PbDfg5p in the fungal cell wall. Enzymatic treatments identified PbDfg5p as a beta-glucan linked protein that undergoes N -glycosylation. The rPbDfg5p bound to extracellular matrix components, indicating that those interactions could be important for initial steps leading to P. brasiliensis attachment and colonization of host tissues. The P. brasiliensis dfg5 nucleotide and deduced protein, PbDfg5p, sequences reported in this paper had been submitted to the GenBank database under Accession Nos AY307855 (cDNA) and DQ534495 (genomic). Copyright (C) 2007 John Wiley & Sons, Ltd.
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We imaged pores on the surface of the cell wall of three different industrial strains of Saccharomyces cerevisiae using atomic force microscopy. The pores could be enlarged using 10 mM diamide, an SH residue oxidant that attacks surface proteins. We found that two strains showed signs of oxidative damage via changes in density and diameter of the surface pores. We found that the German strain was resistant to diamide induced oxidative damage, even when the concentration of the oxidant was increased to 50 mM. The normal pore size found on the cell walls of American strains had diameters of about 200nm. Under conditions of oxidative stress the diameters changed to 400nm.This method may prove to be a useful rapid screening process (45-60 min) to determine which strains are oxidative resistant, as well as being able to screen for groups of yeast that are sensitive to oxidative stress. This rapid screening tool may have direct applications in molecular biology (transference of the genes to inside of living cells) and biotechnology (biotransformations reactions to produce chiral synthons in organic chemistry.
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The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.
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A superfície interna das bisnagas fabricadas com alumínio não revestido e revestido com resina epóxi, utilizadas para acondicionar cremes, pomadas, géis, etc., foram avaliadas quimicamente e por métodos microbiológicos correlacionados com a aderência de microrganismos. A prova da porosidade e da resistência à remoção da resina foi observada por meio do microscópio eletrônico de varredura (Topcon FM300) e estereoscópio Leica (MZ12) acoplado a Sistema de Digitalização de Imagens. Para avaliar a ação dos microrganismos foram utilizados corpos-de-prova esterilizados (discos de 10mm de diâmetro), imersos em caldo Mueller Hinton (Difco) e colocados em tubos de polipropileno com tampa de rosca (Corning). Foram inoculados tubos com meio de cultura para cada uma das suspensões bacterianas (10(9)UFC/mL) de Streptococcus agalactiae, Staphylococcus aureus, Acinetobacter lwoffii e Candida albicans, incubados a 37°C, sob agitação constante durante 12 dias. O meio de cultura era trocado a cada 3 dias. Após esse período, os corpos-de prova foram removidos, processados e observados em microscópio eletrônico de varredura JEOL-JSM (T330A). A observação por meio do microscopio eletrônico de varredura mostrou a aderência e a formação de biofilme sobre a superfície de alumínio não revestido e revestido com resina epóxi.
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The absorption edge and the bandgap transition of sol-gel-dip-coating SnO2 thin films, deposited on quartz substrates, are evaluated from optical absorption data and temperature dependent photoconductivity spectra. Structural properties of these films help the interpretation of bandgap transition nature, since the obtained nanosized dimensions of crystallites are determinant on dominant growth direction and, thus, absorption energy. Electronic properties of the bulk and (110) and (101) surfaces are also presented, calculated by means of density functional theory applied to periodic calculations at B3LYP hybrid functional level. Experimentally obtained absorption edge is compared to the calculated energy band diagrams of bulk and (110) and (101) surfaces. The overall calculated electronic properties in conjunction with structural and electro-optical experimental data suggest that the nature of the bandgap transition is related to a combined effect of bulk and (101) surface, which presents direct bandgap transition.