359 resultados para MQL with water


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O presente trabalho teve o objetivo de caracterizar a curva de absorção de água em sementes de atemóia (Annona cherimola Mill x Annona squamosa L.) cv. Gefner, submetidas a três métodos de embebição: sementes submersas em água destilada (MSSA), sementes entre papel de filtro embebido em água destilada acondicionada em caixa tipo gerbox (MPEA) e teste-padrão (MTP), com sementes mantidas em rolo de papel de filtro umedecido em água destilada. O delineamento experimental foi o inteiramente casualizado, com 6 tratamentos e 4 repetições de 25 sementes por parcela, constituídos por três métodos de embebição, empregando-se sementes vivas e mortas. O tempo de embebição entre 27; 34 e 47 horas, nos métodos MTP, MPEA e MSSA, representam indicativo para tratamento de sementes, podendo funcionar como tempo mínimo necessário para embebição em solução com reguladores vegetais. Conclui-se que os métodos que caracterizaram as três fases de absorção de água em sementes de atemóia foram o MTP e MPEA com mudança entre as fases I e II após 27 e 34 horas, respectivamente, atingindo a fase III com 234 horas, o que permite determinar o tempo de imersão para tratamentos pré-germinativos.

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Avaliou-se o efeito do enriquecimento da água de irrigação com CO2 sobre índices fisiológicos de desenvolvimento e troca gasosa de folhas de plantas de pepino do tipo japonês, cultivados em ambiente protegido. Os experimentos realizados em duas épocas do ano foram instalados em delineamento experimental de blocos ao acaso com 4 tratamentos e 5 repetições. Os tratamentos foram constituídos pelos híbridos Hokuho e Tsuyataro, irrigados com água comum ou enriquecida com CO2, em uma concentração de 1 no primeiro e 0,25 no segundo experimento. A produção de massa de material seco e área foliar adotaram tendência exponencial, não sendo possível observar o início da diminuição da taxa de produção de massa do material seco aos 63 dias após transplante (DAT). A taxa de crescimento da comunidade e taxa de crescimento relativa do híbrido Hokuho irrigado com água comum foi diferente do irrigado com água enriquecida com CO2, no entanto, no híbrido Tsuyataro foram semelhantes. A taxa de assimilação líquida atingiu a máxima pendente na fase de crescimento vegetativo e floração, e foi reduzida drasticamente após os 20 DAT no híbrido Hokuho, e após os 35 DAT no híbrido Tsuyataro. A razão de área foliar diminuiu ligeiramente nos dois híbridos com o desenvolvimento do cultivo. No início observaram-se diferenças entre irrigação com água comum e enriquecida com CO2, porém após 20 DAT não se apreciaram mais diferenças. Quanto a troca gasosa, a taxa assimilatória líquida de CO2 e de transpiração, conductância estomática e eficiência no uso da água foram semelhantes entre plantas irrigadas com água comum e enriquecida com CO2 durante o primeiro semestre. Já no segundo semestre, maiores valores foram registrados pelas plantas irrigadas com água enriquecida.

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

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

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

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Bivalve filter feeders are sessile animals that live in constant contact with water and its pollutants. Their gill is an organ highly exposed to these conditions due to its large surface and its involvement in gas exchanges and feeding. The bivalve Mytella falcata is found in estuaries of Latin America, on the Atlantic as well as the Pacific Coast. It is commonly consumed, and sometimes is the only source of protein of low-income communities. In this study, gill filaments of M. falcata were characterized using histology, histochemistry and transmission electron microscopy for future comparative studies among animals exposed to environmental pollutants. Gill filaments may be divided into abfrontal, intermediate and frontal zones. Filaments are interconnected by ciliary discs. In the center of filaments, haemocytes circulate through a haemolymph vessel internally lined by an endothelium and supported by an acellular connective tissue rich in polysaccharides and collagen. The abfrontal zone contains cuboidal cells, while the intermediate zone consists of a simple squamous epithelium. The frontal zone is composed of five columnar cell types: one absorptive, mainly characterized by the presence of pinocytic vesicles in the apical region of the cell; one secretory, rarely observed and three ciliated with abundant mitochondria. All cells lining the filament exhibit numerous microvilli and seem to absorb substances from the environment. PAS staining was observed in mucous cells in the frontal and abfrontal zones. Bromophenol blue allowed the distinction of haemocytes and detection of a glycoprotein secretion in the secretory cells of the frontal region. The characteristics of M. falcata gill filaments observed in this study were very similar to those of other bivalves, especially other Mytilidae, and are suitable for histopathological studies on the effect of water-soluble pollutants. (C) 2007 Elsevier Ltd. All rights reserved.

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

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

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Objectives: To evaluate the hypothesis that a process of hydrofluoric acid precipitate neutralization and fatigue load cycling performed on human premolars restored with ceramic inlays had an influence on microtensile bond strength results (MTBS). Methods: MOD inlay preparations were performed in 40 premolars (with their roots embedded in acrylic resin). Forty ceramic restorations were prepared using glass-ceramic (IPS Empress). The inner surfaces of all the restorations were etched with 10% hydrofluoric acid for 60 seconds, rinsed with water and dried. The specimens were divided into two groups (N=20): 1-without neutralization; 2-with neutralization. All the restorations were silanized and adhesively cemented (self-curing and self-etching luting composite system, Multilink). Ten premolars from each group were submitted to mechanical cycling (1,400,000 cycles, 50N, 37 degrees C). After cycling, the samples were sectioned to produce non-trimmed beam specimens (vestibular dentin-restoration-lingual dentin set), which were submitted to microtensile testing. Results: Bond strength was significantly affected by the surface treatment (p<0.0001) (no neutralization > neutralization) and mechanical cycling (p<0.0001) (control > cycling) (2-way ANOVA and Tukey test, alpha=.05). Conclusion: Hydrofluoric acid precipitate neutralization appears to significantly damage the resin bond to glass-ceramic and should not be recommended. The clinical simulation of the specimens, by using mechanical cycling, is important when evaluating the ceramic-dentin bond.

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Objectives. This study characterized the feldspathic ceramic surfaces after various silanization protocols.Methods. Ceramic bars (2 mm x 4 mm x 10 mm) (N = 18) of feldpathic ceramic (VM7, VITA Zahnfabrik) were manufactured and finished. Before silane application, the specimens were ultrasonically cleaned in distilled water for 10 min. The ceramic specimens were randomly divided into nine groups (N = 2 per group) and were treated with different silane protocols. MPS silane (ESPE-Sil, 3M ESPE) was applied to all specimens and left to react at 20 degrees C for 2 min (G20). After drying, the specimens were subjected to heat treatment in an oven at 38 degrees C (G38), 79 degrees C (G79) or 100 degrees C (G100) for 1 min. Half of the specimens of each group were rinsed with water at 80 degrees C for 15 s (G20B, G38B, G79B, G100B). The control group (GC) received no silane. Attenuated total reflection infrared Fourier transform analysis (ATR FT-IR) was performed using a spectrometer. Thickness of silane layer was measured using a spectroscopic ellip-someter working in the lambda = 632.8 nm (He-Ne laser) at 70 degrees incidence angle. Surface roughness was evaluated using an optical profilometer. Specimens were further analyzed under the Scanning Electron Microscopy (SEM) to observe the topographic patterns.Results. ATR FT-IR analysis showed changes in Si-O peaks with enlarged bands around 940 cm(-1). Ellipsometry measurements showed that all post-heat treatment actions reduced the silane film thickness (30.8-33.5 nm) compared to G20 (40 nm). The groups submitted to rinsing in hot water (B groups) showed thinner silane films (9.8-14.4 nm) than those of their corresponding groups (without washing) (30.8-40 nm). Profilometer analysis showed that heat treatments (Ra approximate to 0.10-0.19 mu m; Rq approximate to 0.15-0.26 mu m) provided a smoother surface than the control group (Ra approximate to 0.48 mu m; Rq approximate to 0.65 mu m). Similar patterns were also observed in SEM images.Significance. Heat treatment after MPS silane application improved the silane layer network. Rinsing with boiling water eliminated the outmost unreacted regions of the silane yielding to thinner film thicknesses. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)