Avaliação de diferentes tipos de atmosferas modificadas na vida útil de carambolas minimamente processadas

Este trabalho teve por objetivo a avaliação da vida útil potencial de carambolas cv. Golden Star, minimamente processadas, armazenadas em diferentes tipos de embalagens plásticas, para a concepção da atmosfera modificada. Os frutos colhidos fisiologicamente maturos apresentaram coloração verde-amarelada, sólidos solúveis (SS) médios de 6,8 ºBrix e massa média de 185 g. Antes da aplicação dos tratamentos, os frutos foram selecionados, higienizados em solução de hipoclorito de sódio (NaOCl) a 100 mg. L-1, resfriados por 12 horas a 15 ± 0,5 °C, seccionados transversalmente, sendo então novamente higienizados em solução de NaOCl a 10 mg.L-1, por 3 minutos. em seguida, os pedaços em forma de estrelas foram acondicionados em bandejas rígidas de poliestireno, com capacidade para 250 g, e revestidas com os seguintes materiais: T1: filme plástico perfurado de polietileno de baixa densidade (PEBD), de 0,006 mm; T2: filme plástico poliolefínico com antiembassamento da Dupont® (AGF), de 0,015 mm; T3: filme plástico poliolefínico da Dupont® (HF), de 0,015 mm; T4: filme plástico de PEBD, de 60 µm; T5: filme plástico de PEBD, de 80 µm; T6: filme plástico de polipropileno (PP), de 22 µm, e T7: bandeja rígida de polietileno tereftalato (PET), com capacidade para 500 mL, com tampa do mesmo material. As embalagens foram então armazenadas em câmara frigorífica a 12 ± 0,5 °C e 90 ± 3% de U.R, por 18 dias. Observou-se que não houve diferença significativa quanto aos sólidos solúveis (SS) e acidez titulável (AT). O maior número de microrganismos e valor de pH foram observados nos frutos embalados nos filmes plásticos de PEBD de 0,006 mm, AGF e HF de 0,015 mm da Dupont®. Entretanto, os frutos acondicionados nas embalagens PET apresentaram o maior teor de ácido ascórbico. da mesma forma, somente nas embalagens PET é que se conseguiu modificação atmosférica eficiente do ponto de vista da manutenção dos atributos de qualidade durante o AR. Assim, esse tratamento proporcionou adequado controle microbiológico e manutenção das características de qualidade por 18 dias para as carambolas minimamente processadas.

Radiação gama e atmosfera modificada passiva na qualidade de goiabas 'Pedro Sato'

O objetivo deste trabalho foi avaliar o efeito da irradiação gama associada à atmosfera modificada passiva na qualidade pós-colheita de goiabas 'Pedro Sato', verificando suas características físico-químicas. Foram utilizadas goiabas provenientes da região de Vista Alegre do Alto-SP,Brasil. Após a colheita, as goiabas foram imediatamente transportadas ao Laboratório de Frutas e Hortaliças, pertencente ao Departamento de Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas - UNESP - Câmpus de Botucatu-SP, onde foram armazenadas a 10ºC e 90-95%UR, em câmara frigorífica, por 28 dias. Os tratamentos foram: controle 1 (sem embalagem e sem irradiação); controle 2 (embalagem de poliestireno (PS) + polietileno de baixa densidade (PEBD) e sem irradiação); tratamento 1 (PS+PEBD e 0,2kGy); tratamento 2 (PS+PEBD e 0,6kGy), e tratamento 3 (PS+PEBD e 1,0kGy). As análises realizadas foram: firmeza, sólidos solúveis (SS), acidez titulável (AT) e índice de maturação. Foi utilizado o delineamento inteiramente casualizado, com esquema fatorial 5 x 5 (tratamento x tempo). Concluiu-se que as altas doses de irradiação promoveram efeito negativo nas características físico-químicas da goiaba 'Pedro Sato', e que apenas a menor dose utilizada (0,2kGy) associada à atmosfera modificada conservou frutos com maior qualidade e aceitabilidade, indicado por maiores índice de maturação e teor de sólidos solúveis obtidos.

Qualidade pós-colheita de mangas, não-refrigeradas, e submetidas ao controle da ação do etileno

O presente trabalho objetivou-se na caracterização físico-química de mangas cv. Tommy Atkins e Haden, submetidas ao controle da ação do etileno, através da exposição dos frutos à ação de adsorvedores de etileno. Os frutos colhidos em estádio de fisiologicamente maturos foram embalados em filmes de polietileno de baixa densidade (PEBD) de 0,006 mm de espessura, com ou sem o sachê de adsorção de etileno, e acondicionados em embalagens de papelão (0,65 x 0,52 m), sem o controle da temperatura e da umidade relativa (30 ± 3 ºC e 70 ± 5 % de U.R.). Os tratamentos ficaram constituídos dessa maneira: T1 - mangas cv. Tommy Atkins, com o sachê de adsorção; T2 - mangas cv. Tommy Atkins, sem o sachê de adsorção; T3- mangas cv. Haden com o sachê de adsorção, e T4 - mangas cv Haden sem o sachê de adsorção. As análises de firmeza de polpa, sólidos solúveis (SS), acidez titulável (AT), pH, ácido ascórbico e concentração de etileno foram realizadas na instalação do experimento (dia 0), e aos 7; 14; 21; 28 e 35 dias; e aos 35 dias foi realizado um teste de preferência. Ao final do experimento, observou-se que, em ambas as cultivares, a menor concentração de etileno nas embalagens, a maior firmeza de polpa, a maior contenção no avanço e na diminuição do SS e AT, respectivamente, bem como a melhor manutenção do conteúdo de ácido ascórbico foram detectadas nos frutos acondicionados em embalagens contendo o sachê de adsorção de etileno. Não foram detectadas variações significativas nos valores de pH. No teste de preferência, houve variação significativa, onde os frutos acondicionados sob ação do adsorvedor de etileno foram preferidos por parte dos julgadores.

Adição de geomanta e tecido não tecido de polipropileno em cimentos geopoliméricos de pega rápida

Geopolymers are cementing materials that depict a number of advantages compared to Portland cement. Contrary to the latter, geopolymers are synthesized at room temperature, thus significantly reducing the emission of CO2 to the atmosphere. Moreover, the composition and synthesis reactions can be tailored to adjust the setting time of the material as well as its compressive mechanical strength. It is then possible to produce geopolymeric cements with short setting times and high compressive strength, although relatively brittle. The objective of the present study was to produce and characterize composite materials by reinforcing fastsetting geopolymeric matrixes with polypropylene geosynthetics (geomats and geotextiles) in an attempt to improve the toughness and tensile strength of the cementing material. Geosynthetics have been increasingly used to reinforce engineering structures, providing higher strength and better toughness. In particular, polypropylene nonwoven and geomats depict other attractive properties such as low density, durability, impact absorption and resistance to abrasion. Fast-setting geopolymers were then synthesized and reinforced with polypropylene nonwoven and geomats. The mechanical strength of the materials, reinforced or not, was characterized. The results showed that relatively short setting times and adequate flowing behavior were achieved by adjusting the composition of the geopolymer. In addition, it is possible to improve the fracture resistance of geopolymeric cements by adding polypropylene geosynthetics. The best results were achieved by reinforcing geopolymer with polypropylene TNT

Compósitos híbridos: desenvolvimento de configuração e efeitos de umidificação

The advantage in using vegetable fibres in place of synthetic fibres such as glass fibre, for reinforcements in composites are: biodegradability, low cost, low density, good tenacity, good thermal properties, low energy content and reduced use of instruments for its treatment or processing. Even though, problems related to low mechanical performance of some of the natural fibres, has caused difficulty in their direct application in structural elements. The use of alternative materials like hybrid composites has been encouraged, thus trying to better the structural performance of the composites with natural fibres. This work presents a comparative study of the strength and stiffness of hybrid composites with orthopthalic polyester matrix reinforced with E-fibre glass, jute and curauá. The experimental part includes uniaxial tension and three point bending tests to determine the mechanical properties of the final product. The hybrid composite was manufactured in a local industry and was in the form of laminates. All the samples were projected to withstand the possible structural applications as reservoirs and pipes. CH (laminated hybrid composite with glass and curauá fibres). The results obtained show clearly the influence of the hybridization in all the types tested and indicate a good mechanical performance of the composite with glass/curauá fibres in relation to the composite with glass fibres. Aspects in relation to the interfaces glass/curauá composites besides the fracture characteristics for all loading types were also analysed

Efeitos do envelhecimento ambiental acelerado em compósitos poliméricos

The advantages of the use of vegetable fibers on the synthetic fibers, such as glass fibers, in the reinforcements in composites are: low cost, low density, good tenacity, good thermal properties and reduced use of instruments for their treatment or processing. However, problems related to poor performance of some mechanical natural fibers, have hindered its direct use in structural elements. In this sense, the emergence of alternative materials such as hybrids composites, involving natural and synthetic fibers, has been encouraged by seeking to improve the performance of structural composites based only on natural fibers. The differences between the physical, chemical and mechanical properties of these fibers, especially facing the adverse environmental conditions such as the presence of moisture and ultraviolet radiation, is also becoming a concern in the final response of these composites. This piece of research presents a comparative study of the strength and stiffness between two composite, both of ortoftalic polyester matrix, one reinforced with fibers of glass-E (CV) and other hybrid reinforced with natural fibers of curauá and fiberglass-E (CH). All the comparative study is based on the influence of exposure to UV rays and steam heated water in composites, simulating the aging environment. The conditions for the tests are accelerated through the use of the aging chamber. The composites will be evaluated through tests of uniaxial static mechanical traction and bending on three points. The composite of glass fiber and hybrid manufacturing industry are using the rolling manual (hand lay-up) and have been developed in the form of composites. All were designed to meet possible structural applications such as tanks and pipes. The reinforcements used in composites were in the forms of short fiber glass-E quilts (450g/m2 - 5cm) of continuous wires and fuses (whose title was of 0.9 dtex) for the curauá fibers. The results clearly show the influence of aging on the environmental mechanical performance of the composite CV and CH. The issues concerning the final characteristics of the fracture for all types of cargoes studied were also analyzed

Caracterização da comunidade de plantas aquáticas de dezoito reservatórios pertencentes a cinco bacias hidrográficas do Estado de São Paulo

O objetivo deste trabalho foi o de avaliar e comparar a composição florística de 18 reservatórios pertencentes a cinco bacias hidrográficas do Estado de São Paulo. Os levantamentos foram realizados no período de fevereiro a setembro de 2002, com o auxílio de um barco. Percorreu-se a margem dos reservatórios das bacias hidrográficas dos rios Paraíba, Paraná, Paranapanema, Grande e Tietê, à velocidade de 30 km h-1. A cada 20 minutos, estabeleceu-se um ponto de amostragem, determinando-se sua posição por meio de GPS. em cada ponto, em área de 1.000 m², identificaram-se as espécies ocorrentes e respectivas densidades, em porcentagem da área amostrada. Foram identificadas 39 espécies, distribuídas em 21 famílias, destacando-se as flutuantes Salvinia auriculata, Eichhornia crassipes, Eichhornia azurea e Pistia stratiotes e as emersas Polygonum lapathifolium, Brachiaria arrecta,Brachiaria mutica, Cyperus sp. e Typha latifolia, considerando as quatro espécies com maior freqüência em cada bacia. O maior índice de similaridade (0,71) ocorreu entre as bacias dos rios Paranapanema e Grande, e o menor (0,49), entre as bacias dos rios Paraíba e Tietê.

Desenvolvimento de sistemas de pastas leves para aplicação em cimentação de poços petrolíferos com baixo gradiente de fratura

All around the world, naturally occurring hydrocarbon deposits, consisting of oil and gas contained within rocks called reservoir rocks , generally sandstone or carbonate exists. These deposits are in varying conditions of pressure and depth from a few hundred to several thousand meters. In general, shallow reservoirs have greater tendency to fracture, since they have low fracture gradient, ie fractures are formed even with relatively low hydrostatic columns of fluid. These low fracture gradient areas are particularly common in onshore areas, like the Rio Grande do Norte basin. During a well drilling, one of the most favorable phases for the occurrence of fractures is during cementing, since the cement slurry used can have greater densities than the maximum allowed by the rock structure. Furthermore, in areas which are already naturally fractured, the use of regular cement slurries causes fluid loss into the formation, which may give rise to failures cementations and formation damages. Commercially, there are alternatives to the development of lightweight cement slurries, but these fail either because of their enormous cost, or because the cement properties were not good enough for most general applications, being restricted to each transaction for which the cement paste was made, or both reasons. In this work a statistical design was made to determine the influence of three variables, defined as the calcium chloride concentration, vermiculite concentration and nanosilica concentration in the various properties of the cement. The use of vermiculite, a low density ore present in large amounts in northeastern Brazil, as extensor for cementing slurries, enabled the production of stable cements, with high water/cement ratio, excellent rheological properties and low densities, which were set at 12.5 lb / gal, despite the fact that lower densities could be achieved. It is also seen that the calcium chloride is very useful as gelling and thickening agent, and their use in combination with nanosilica has a great effect on gel strength of the cement. Hydrothermal Stability studies showed that the pastes were stable in these conditions, and mechanical resistance tests showed values of the order of up to 10 MPa

Influence of a probiotic soy product on fecal microbiota and its association with cardiovascular risk factors in an animal model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Soy beta-Conglycinin (7S Globulin) Reduces Plasma and Liver Cholesterol in Rats Fed Hypercholesterolemic Diet

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Abnormalities in apolipoprotein and lipid levels in an HIV-infected Brazilian population under different treatment profiles: the relevance of apolipoprotein E genotypes and immunological status

HIV infection is associated with disturbances in lipid metabolism due to a host's response mechanism and the current antiretroviral therapy. The pathological appearance and progression of atherosclerosis is dependent on the presence of injurious agents in the vascular endothelium and variations in different subsets of candidate genes. Therefore, the Hha I polymorphism in the apolipoprotein E gene was evaluated in addition to triglycerides, total cholesterol, very low-density lipoprotein (VLDL), LDL, high-density lipoprotein (HDL), and apolipoprotein (apo) Al, B and E levels in 86 Brazilian HIV-infected patients and 29 healthy controls. The allele frequency for apoE in the HIV-infected group and controls was in agreement with data on the Brazilian population. Dyslipidemia was observed in the HIV group and verified by increased levels of triglycerides, VLDL and apoE, and decreased levels of HDL and apoAl. The greatest abnormalities in these biochemical variables were shown in the HIV-infected individuals whose immune function was more compromised. The effect of the genetic variation at the APOE gene on biochemical variables was more pronounced in the HIV-infected individuals who carried the apoE2/3 genotype. The highly active antiretroviral therapy (HAART)-receiving group presented increased levels of total cholesterol and apoE. Dyslipidemia was a predictable consequence of HIV infection and the protease inhibitors intensified the increase in apoE values.

Xylan from corn cobs, a promising polymer for drug delivery: Production and characterization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Teor lipídico da dieta, lipídios séricos e peso corporal em ratos exercitados

OBJETIVO: Analisar os efeitos de diferentes níveis de triglicerídeos fornecidos pela dieta sobre os parâmetros séricos triglicerídeos e lipoproteínas de alta densidade e o peso corporal de ratos sedentários e exercitados. MÉTODOS: Foram utilizados ratos Wistar, alimentados com dietas controle (7%peso/peso) e hiperlipídica (14% peso/peso) e subdivididos em sedentários e exercitados, por um período de 8 semanas. RESULTADOS: Verificou-se que o peso não diferiu entre os grupos, embora o consumo tenha sido reduzido nos grupos com dieta hiperlipídica. Os níveis de triglicerídeos não foram aumentados com a dieta rica em gordura e o HDL-colesterol se elevou apenas entre os animais exercitados que tiveram dieta normolipídica. CONCLUSÃO: A intensidade e o tempo de exercício físico influenciam de maneira mais aguda os níveis de HDL-colesterol em comparação aos níveis de triglicérides. Sugere-se que a dieta hiperlipídica deveria sobrepor (14%peso/peso) de gordura para que houvesse alterações relevantes nos parâmetros lipídicos e supostamente um aumento da performance física.

Effect of target bias on magnetic field enhanced plasma immersion ion implantation

Recent studies have demonstrated that sheath dynamics in plasma immersion ion implantation (PIII) is significantly affected by an external magnetic field, especially in the case when the magnetic field is parallel to the workpiece surface or intersects it at small angles. In this work we report the results from two-dimensional, particle-in-cell (PIC) computer simulations of magnetic field enhanced plasma immersion implantation system at different bias voltages. The simulations begin with initial low-density nitrogen plasma, which extends with uniform density through a grounded cylindrical chamber. Negative bias voltage is applied to a cylindrical target located on the axis of the vacuum chamber. An axial magnetic field is created by a solenoid installed inside the target holder. A set of simulations at a fixed magnetic field of 0.0025 T at the target surface is performed. Secondary electron emission from the target subjected to ion bombardment is also included. It is found that the plasma density around the cylindrical target increases because of intense background gas ionization by the electrons drifting in the crossed E x B fields. Suppression of the sheath expansion and increase of the implantation current density in front of the high-density plasma region are observed. The effect of target bias on the sheath dynamics and implantation current of the magnetic field enhanced PIII is discussed. (C) 2007 Elsevier B.V. All rights reserved.

Efeitos do substrato e da densidade populacional sobre as atividades comportamentais e níveis de homócitos em relação à densidade em Litopenaeus vannamei (BOONE, 1931)

Carciniculture in Brazil occupies world-wide prominence due to shrimp culture, and the state of Rio Grande do Norte has presented the best results in the culture of the Litopenaeus vannamei in the last decade. This species has been shown to adapt easily to different environments and is between the five most cultivated penaeids of the world. The ponds are usually constructed in areas close to water courses and estuaries. Stock density and substrate ponds can pollute environment, causing losses in the growth and survival of the shrimps, being considered stress factors. Shrimps in inadequate densities and substrates can result reduced productivity of the farm; and favor diseases. So, it is important to verify how these variables influence the development of the animals in the culture farms. Our objective was to study the influence of the type of substrate and the stock density on the behavior and haemocyte count of the L. vannamei. Individually marked juvenile shrimps were kept in aquaria with 30 L of seawater and continuous aeration, in 12L-12D photoperiod. They were observed through Ad libitum and focal sampling instantaneous methods during thirty days, five times per week, six times per day (8:00 to 18:00) in windows of 15 minutes every two hours. The marking of carapace permitted quantifying molting and the feeding was supplied three times a day. Two experiments were carried out: the first one tested animals in the three different substrates (fine sand, smaller rocks-SPP and biggest rocks-SGR) with 33 shrimp/m2. In the second one, the animals were tested in three stock densities (26, 52 and 66 shrimp/m2) in fine sand substrate. At the end of experiment, biometry (first and second ones) and haemocyte count (second one) were made. The behavior of the L. vannamei seems to have been influenced by substrate and stocking density. In low granulometry of the substrate; the exploratory behavior became more frequent and inactivity of the shrimps was reduced. Burrowing was registered in sand substrate, specially in the initial period of the day. Cleaning was gradually higher along the day, presenting the biggest levels as the dark phase approached. The ingestion of feeding was more frequent in low density, and the animals were bigger and heavier at the end of the experiment. In the fine sand condition, the animals presented better growth, probably associated with the burrowing. The molting was equivalent in all types of substrate, but it was more frequent in high densities. Mortality of the shrimps was more frequent in high densities, and cannibalism and diseases were also registered in that condition. The clinical signals were similar to the ones of infectious mionecrosis (IMNV), generally associated with environment and physical stress. The haemocyte count was low for the hematologic standards of the penaeid, which we attributed for greater dilution of haemolymph in the postmolting phase. Smaller shrimps presented lower levels of haemocytes in relation to the bigger animals, count was also low in 26 shrimp/m2 density. The study demonstrates that stocking density and the granulometry of the substrate can affect the welfare, the health and the behavior of the L. vannamei. The sand substrate and low stocking density can be important tools in the management systems of shrimp production