916 resultados para LAMELLAR MORPHOLOGY


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The Melastomataceae display greater trichome diversity. Dr. Wurdack, in his Atlas of hairs, recognized 46 types of trichomes for the Neotropical Melastomataceae through the Scanning Electron Microscope (SEM), and referred 17 of them to the genus Tibouchina. The trichome morphology has been extensively used in the delimitation of the taxa in Melastomataceae, as well as in previous studies by Cogniaux, the monograph of Brazilian Melastomataceae published in 1885. The morphology of the trichomes was essential for the delimitation of several species in Tibouchina section Pleroma. The use of SEM provided the best characterization of the 15 different types of trichomes recognized among the 41 species examined. These were described based on the morphological appearance, both optical microscopy and scanning electron microscopy, and illustrated by scanning electron micrographs and photomicrographs.

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

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Richards gland in the epiponine wasp Metapolybia docilis occurs at the anterior side of the 5(th) abdominal sternite, and is formed by approx. 360 secretory cells. The cells discharge their secretory products through accompanying duct cells into a reservoir that is formed by the invaginated intersegmental membrane between the 4(th) and 5(th) sternites. The ultrastructural characteristics of the secretory cells are indicative for the production of a non-proteinaceous secretion, which is in line with the trail substance that is used by these wasps during their swarm-founding.

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Objectives: To evaluate the influence of different protocols for resin cement removal during cementation on biofilm formation.Methods: Twenty-eight ceramic blocks, which were injected under pressure, were placed over enamel blocks obtained from freshly extracted bovine incisors. The ceramic blocks were cemented to the enamel blocks using a dual-cured resin cement and the excess resin was removed according to the experimental group: TS: Teflon spatula; BR: brush; BR+: brush and polishing; SB+: scalpel blade and polishing. After autoclaving, the samples were colonised by incubation in a sucrose broth suspension standardised with Streptococcus mutans in microaerophilic stove. Specimens were quantitatively analysed for bacterial adherence at the adhesive interface using confocal laser scanning microscopy and counting the colony forming units, and qualitatively analysed using SEM. The roughness (Ra/Rz/RSm) was also analysed. Data were analysed by 1-way ANOVA and Tukey's test (5%).Results: The roughness values ranged from 0.96 to 1.69 mu m for Ra (p > 0.05), from 11.59 to 22.80 mu m for Rz (p = 0.02 < 0.05) and from 293.2 to 534.3 mu m for RSm (p = 0.00). Bacterial adhesion varied between 1,974,000 and 2,814,000 CFU/ml (p = 0.00). Biofilm mean thickness ranged from 0.477 and 0.556 mu m (p > 0.05), whilst the biovolume values were between 0.388 and 0.547 mu m(3)/mu m(2) (p = 0.04). Lower values for roughness, bacterial adhesion, biofilm thickness and biovolume were found with BR, whilst TS presented the highest values for most of the parameters. SEM images confirmed the quantitative values.Conclusions: The restoration margin morphology and interface roughness affects bacterial accumulation. The brush technique promoted less bacterial colonisation at the adhesive interface than did the other removal methods.Clinical significance: The brush technique seems to be a good option for removing the excess resin cement after adhesive cementation in clinical practice, as indicated by its better results with lower bacterial colonisation. (C) 2012 Elsevier Ltd. All rights reserved.

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International Journal of Paediatric Dentistry 2012; 22: 435441 Background. Hydrophilic adhesives may be used as pit and fissure sealants (sealants), but there is concern about the ability of self-etching adhesives to bond sealants to enamel. Aim. To study the bond strength (BS) and morphology of adhesive systems used as sealants. Design. OptiBond FL, OptiBond All-in-One, combined OptiBond All-in-One + OptiBond FL adhesive, and Fluroshield were applied to the occlusal surfaces of 16 primary molars (n = 4). Teeth were stored in distilled water (24 h at 37 degrees C) and sectioned through the interface to obtain sticks (0.8 mm2) tested under a tensile load (0.5 mm/min). Failure modes were observed. Data were analysed by ANOVA and Tukeys tests (a = 5%). The morphology of 12 primary molars was examined in terms of the etching pattern and resin reproduction. Results. Differences in the BS were found (P = 0.001), with OptiBond FL showing the highest (36.84 +/- 5.7 MPa), Fluroshield (24.26 +/- 2.13 MPa) and OptiBond All-in-One (17.12 +/- 4.97 MPa) similar, and OptiBond All-in-One + OptiBond FL adhesive the lowest (9.8 +/- 2.94 MPA). OptiBond FL showed the best results in terms of morphology. Conclusion. Under the conditions of this study, OptiBond FL was the best material to be used for sealing.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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Polymeric precursor solution (Pechini method) was used to deposit LiNbO3 thin films by spin-coating on (100) silicon substrates. X-ray diffraction data of thin films showed that the increase of oxygen flow promotes a preferred orientation of (001) LiNbO3 planes parallel to the substrate surface. Surface roughness and grain size, observed by atomic force microscopy, change also with oxygen flow.

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PLZT thin films were prepared by a dip coating process using Pechini's method, also known as polymeric precursor method. The PLZT solution was obtained from a mixture of the individual cation solutions and the process to prepare each solution is based on metallic citrate polymerization. The viscosity of the PLZT solution was adjusted at 40 cP while the ionic concentration was adjusted at 0.1 M. PLZT solutions were deposited on silicon (100) and platinum coated silicon (100) substrates with withdrawal speed at 5 mm/min. The coated substrates were thermally treated with a heating rate of 1 degreesC/min up to 300 degreesC and 5 degreesC/min up to 650 degreesC in order to obtain homogeneous and cracks free films. The influence of oxygen flow on crystallization and morphology of PLZT (9/65/35) thin film is discussed. (C) 2002 Elsevier B.V. Ltd and Techna S.r.l. All rights reserved.

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PLZT thin films were prepared by a dip-coating process using Pechini's method. The PLZT solution was obtained from the mixture of the cation solutions. The viscosity of the solution was adjusted in the range of 20-40 cP, while the ionic concentration was adjusted in the range of 0.1 and 0.2 M. PLZT solutions were deposited on Si (1 0 0) substrate with withdrawal speed at 5 mm/min. The coated substrates were thermally treated with heating rate of 1 degreesC/min up to 300 and 5 degreesC/ min up to 650 degreesC in order to obtain homogeneous and crack free films. The influence of viscosity and ionic concentration on crystallization and morphology of PLZT (9/65/35) thin film will be discussed. (C) 2001 Elsevier B.V. B.V. All rights reserved.

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

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Estudou-se a anatomia de raízes, caules, folhas e escapos de espécies de Paepalanthus subseção Aphorocaulon. Estas plantas apresentam caules reduzidos com folhas em roseta, de onde crescem os paracládios (sistemas de inflorescências). As espécies apresentam raízes com epiderme unisseriada e córtex com células isodiamétricas. Tanto os caules reduzidos como os paracládios apresentam espessamento resultante da atividade do periciclo, denominado Meristema de Espessamento Primário (MEP). Ambos apresentam estrutura anatômica semelhante. Os escapos apresentam endoderme descontínua, periciclo sinuoso, o córtex apresenta costelas salientes (5-6). As folhas apresentam células epidérmicas alongadas no sentido longitudinal com paredes levemente espessadas, estômatos somente na face abaxial, com câmara subestomática especializada, feixes vasculares colaterais com bainha dupla. Essas estruturas anatômicas são comuns para as espécies da subseção Aphorocaulon. Algumas características anatômicas observadas nestas espécies são típicas de plantas que crescem nos campos rupestres.

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Este estudo teve a finalidade de fornecer dados morfológicos de ovos de D. renale e do desenvolvimento de larvas de primeiro estádio em ovos mantidos em diferentes temperaturas. Os ovos foram obtidos por centrífugação da urina de cães parasitados e colocados em placas de Petri em estufa BOD, durante 90 dias. O experimento consistiu de três tratamentos (GI - 15 ºC, GII - 20 ºC e GIII - 26 ºC) com cinco repetições cada. Os ovos apresentaram tamanho médio de 67,23 x 42,78 µm, e o tempo médio de incubação foi inversamente proporcional à temperatura de incubação e as larvas apresentaram motilidade por aproximadamente uma semana após sua formação.