844 resultados para coat
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The purpose of this study was to evaluate through radiographic and microscopic analysis the efficiency of the filling techniques by vertical hidraulic compression after the root canal mechanical instrumentation in vitro as well to evaluate the marginal apical leakage through macroscopic and microscopic analysis. Thirty human mandibular molars were used , they were divided on three groups, these were subdivided on six subgroups with five specimens each, come down to 106 root canals filled. Initially, the teeth were instrumented with Profile system series 29 and filled with two ways: single accessory cone or single cone associated with gutta-percha secundary cone, with Fill Canal sealer or Sealer 26. Completed the filling, the teeth were coated with araldit and finger -nail polish except for the apical 2 mm and dried for 3 hours, thep radiographs were taken of the teeth in orto and disto-radiai directions. Next, the coronal seal was carried out with composite resin photopolymerized and with their process of making impermeable. Teeth of positive controls were used without araldit and finger-nail polish whereas the negative controls were used with total coat of araldit and finger-nail polish. The specimens were placed in 2% Methylene Blue dye for 24 hours and thermocycled for 7 days. Afterwards, sections were made of each tooth at mesial and distal roat, after this the teeth were radiographed at buccolíngual direction for a macroscopic analysis and at buccolingual and mesiodistal directions for assessment of the marginal apical leakage. Cross sections were made 3 mm to 3mm since the tooth apice. The sections obtained for each group were observed with a stereomicroscope to evaluate the quality of the root canal filling and the marginal apical leakage. The results showed that: In the four techniques the marginal dye leakage was present in the apical third; in all groups the quality of the root canal filling in the radiography was better at mesial root canal and the single cone technique showed inefficient when only a single distal root canal was present. In the radiographic evaluation the best quality of the root canal filling was observed in the 1A group (single accessory cone + FiIl Canal), as in the mesial root as in the distal root wich Shcwed twe root canals: when the distaI root had only one canal. the best result was showed by 28 group (single accessory cone associated with secundary cone + Fill Canal) In the macroscopic analysis of longitudinal !eaKage (outside surface). less leakage was showed as In the mesial root as in the distal root in the negative control group (3) followed 2A group (single accessory cone + Sealer 26). When the microscopic analysis of tranversal leakage of both roots (inside surface) was carried out. the groups that showed less dye leakage were the negative control (38) followed the 28 group (single acessory cone associated with secundary cone + Sealer 26). The homogeneity o filling was best noted in the 1 A group (.single accessoty cone + Fill Canal). The groups that showed less dye penetration in the tranversal leakage (total area) were negative control (3B) and 2B
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This dissertation the results of a research developed in the area of São Bento do Norte and Caiçara do Norte, northern coast of the State of Rio Grande do Norte, during the period of June of 2000 to August of 2001, in the ambit of the projects MAMBMARÉ (CNPq/CTPETRO) and PROBRAL (CAPES/DAAD).The objective principal of this research was the characterization of the sedimentary dynamics of this coast, with base in data of coastal process (winds, currents, waves and tides), with topographical risings (beach profiles and dunes), satellite images and sedimentary analyses. The more specific objectives were accomplished the coastal monitoring of this coast, to verify the maintenance of an erosive tendency or progradacional after the groynes construction for contention of the erosion in the beach of Caiçara do Norte, as well as to verify the influence of the features of bottom of the platform interns adjacent on the pole petroliferous of Guamaré. The executed monitoramento allowed to identify that the movement of the sediments, along the year, in that area, is cyclical, reaching the largest oscillations during the months of winter (deposition) and they will summer (erosion). The sedimentologic studies indicated a general tendency for sands quartzosas, with gravel presence, moderately to good selected, with asymmetry predominantly negative. In agreement with the parameter of Dean (1957), used in the identification of the state morfodinâmico of the beaches, monitored beaches, are basically reflectivas with tendency to middlemen, what frames that space of the coast norteriograndense, as a space strongly vulnerable to erosive processes. The studies developed in the platform, it interns of this area, allowed to visualize for the first time, in large scale, the distribution of the features of the submarine bottom to the batométrico coat of 25 meters. Being pointed out the presence of a high one topographical submerged, with about 5 meters of height, 1 km of width and more than 24 meters of extension, located in the platform it interns in front of São Bento do Norte; coincident with the trend of the system of flaws of Carnaubais. This feature relay an important paper on the control of the sedimentary processes and oceanographic, as well as in the coastal evolution of this area of the RN state, and they affect the area of the pole petroliferous of Guamaré directly. These results contribute to a better knowledge of the processes in the area, and consequently as subsidies implantation of measures of coastal and environmental protection for the cities of São Bento do Norte and Caiçara do Norte, as well as to understand how the geological-sedimentary processes and oceanographic, in this area, are influencing the characteristics geoambientais of the pole petroliferous of Guamaré
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A displasia folicular canina é uma dermatopatia incomum caracterizada clinicamente por alopecia e alterações na qualidade da pelagem. Relata-se o caso de um cão, sem raça definida, 7 meses de idade, macho, levado à consulta por apresentar alopecia progressiva disseminada. O diagnóstico anátomo-clínico da displasia folicular canina do caso ora descrito foi estabelecido pelos dados colhidos na resenha e anamnese, achados do exame dermatológico e osteomuscular e confirmado pelas alterações histológicas dos fragmentos de pele biopsiados. Este artigo visa relatar um caso de displasia folicular canina e comparar com outros casos descritos na literatura, pois são esparsos as descrições na literatura brasileira.
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The objective of this study was to evaluate the attractive capacity and palatability of a commercial extruded diet flavored with the following coats: fish oil (1%); fish oil (1%) + citric acid (.1%); fish oil (1%) + phosphoric acid (.1%); commercial coat (1%) and dende oil (1%), and the control treatment (absence of coat). The red tilapias feeding behavior was evaluated using a complete randomized experimental design, with 72 observations per treatment. Six 750-L aquariums were used; with three fish (100 +/- .50 g) per aquarium. They had access to the diets, through a couple choice (control x test), in a surface round feeder (feedings), disposed on the opposite lateral of the aquariums. The animals were evaluated during fifteen minutes, twice a day. Due to the use of the chemical substances that did not potencialyzed the feeding response of the red tilapia, it was observed that the usual commercial coat and fish oil did not present an effective addictive to stimulate the ingestion of the extruded diet. Only the commercial coat was lightly capable to provoke confrontation during the feeding process.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Caesalpinia echinata and C ferrea var. ferrea have different seed behaviours and seed and fruit types. Comparison of the seed ontogeny and anatomy partly explained the differences in seed behaviour between these two species of Brazilian legumes; some differences were also related to fruit development. The seed coat in C. ferrea consisted of two layers of osteosclereids, as well as macrosclereids and fibres, to form a typical legume seed coat, whereas C. echinata had only macrosclereids and fibres. In C. echinata, the developing seed coat had paracytic stomata, a feature rarely found in legume seeds. These seed coat features may account for the low longevity of C. echinata seeds. The embryogeny was similar in both species, with no differences in the relationship between embryo growth and seed growth. The seeds of both species behaved as typical endospermic seeds, despite their different morphological classification (exendospermic orthodox seeds were described for C. echinata and endospermic orthodox seeds for C. ferrea). Embryo growth in C. ferrea accelerated when the sclerenchyma of the pericarp was developing, whereas embryonic growth in C. echinata was associated with the conclusion of spine and secretory reservoir development in the pericarp. Other features observed included an endothelial layer that secreted mucilage in both species, a nucellar summit, which grew up into the micropyle, and a placental obturator that connected the ovarian tissue to the ovule in C. ferrea. (C) 2004 the Linnean Society of London.
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Hymenaea, a genus of major economic importance, has been the subject of several botanical studies. However, there is disagreement over the origin of the edible fruit pulp of Hymenaea, as there are no ontogenetic studies on this organ. According to some authors, the edible layer results from transformations of the mesocarp and endocarp, while according to others, it is considered a seed aril. There are still others who regard this layer as originating from an undefined region of the pericarp. To understand the nature and origin of the pulp layer, Hymenaea stigonocarpa Mart. ex Hayne ovaries and fruit were processed according to standard techniques. The production of the fruit pulp layer starts immediately after anthesis. During anthesis, the inner epidermal cells of the ovary show periclinal division and form a new layer of cells towards the mesocarp; this remains meristematic and initiates cell production by predominantly periclinal divisions, producing a compact tissue towards the locule. This tissue will become the fruit pulp layer, the inner endocarp. The seed coat shows typical testal structure without evidence of aril formation. This allows us to conclude that the fruit pulp layers are exclusively made from part of the endocarp. We also observed resin cavities on outer mesocarp and outer endocarp.
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Background and Aims the occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution of stomata in seed coats of Swietenia macrophylla and to relate it to the imbibition process and aspects of the structure of the outer integument layers.Methods For the structural and ultrastructural studies, the seeds were processed using the usual techniques and studied under light and scanning electron microscopes. Histochemical tests were employed to identify the cell wall composition in the different seed coat portions. To assess the role of the stomata in the imbibition, non-impervious seeds were compared with partially impervious ones, in which only the embryo, median or hilar regions were left free. Further, the apoplastic pathway marker was employed to confirm the role of the stomata as sites of water passage during imbibition.Key Results A positive relationship was observed between seed coat thickness and stomata density. The stomata were devoid of movement, with a large pore. They occurred in large numbers in the embryo region and extended with lower frequency towards the wing. Imbibition rates were related to stomata density, suggesting that the stomata act as preferential sites for water entry in the S. macrophylla seeds.Conclusions At maturity, the stomata in the seed coat play a significant role in seed imbibition. The data may also infer that these permanently opened stomata have an important role in gas exchange during seed development, aiding embryo respiration.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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According to the literature, the seeds of Chamaecrista lack pleurograms and have pitted testas aligned in vertical lines. Preliminary observations have revealed that these small structures consist of superficial alterations of the testa that are coloured differently to the rest of the seed coat and stand out as pits. However, no anatomical inspection has yet determined the precise composition of these pits. The present work examined the morphology, surface micromorphology, anatomy, and histochemistry of the seed coat of mature seeds of C. desvauxii var. latistipula, C. flexuosa, and C. nictitans var. patellaria in order to elucidate the structural nature of the seed coat pits. For this, seed coats were studied using scanning electron microscopy and light microscopy. Structural modifications were examined in the seed coats of the studied species, and variations were noted in the mucilaginous layer, in the thickness of the palisade layer, and in the presence of larger hypodermic cells. Based on the anatomical features observed, and comparing these with published data on pleurograms in the Caesalpinioideae, it was determined that the structures referred to previously as tegumental pits on Chamaecrista seeds are actually small and numerous pleurograms, reported here for the first time. (c) 2008 The Linnean Society of London.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The embryology and seed structure of Blastocaulon scirpeum (Mart.) Giul. and Paepalanthus scleranthus Ruhland were studied in order to contribute to the embryology of Eriocaulaceae and supply data for future taxonomic studies. Both species present: anther with 4-layered wall; conspicuous endothecium with fibrous thickenings; secretory tapetum with uninucleate cells; successive microsporogenesis forming isobilateral microspore tetrads; bicellular pollen grains; orthotropous, bitegmic and tenuinucellate ovule; micropyle formed by the inner integument alone; megagametophyte of the Polygonum type, with a conspicuous antipodal cyst; nuclear and starchy endosperm; reduced, undifferentiated, and bell-shaped embryo; operculate and endotestal seed; seed coat derived from the two ovule integuments; and tanniniferous endotegmen. In addition, Blastocaulon scirpeum shows a bisporangiate anther and a 3-layered ovary wall, while P. scleranthus presents a tetrasporangiate anther that becomes bisporangiate at maturity, and a 2-layered ovary wall. This investigation shows that the bisporangiate condition does not suffice to separate Blastocaulon from Paepalanthus, since it is common to both. It also indicates, based on several embryological aspects, the proximity of Eriocaulaceae and Xyridaceae, which comply mainly with the features presented by the other commelinid families. These results may be used in future cladistic analysis of the family, and contribute to a better understanding of its phylogeny.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Foram descritos e ilustrados aspectos morfo-anatômicos das sementes de Esenbeckia grandiflora Mart., visando o conhecimento dos tegumentos, endosperma e embrião. As sementes são de elipsóides a piramidais, marrom-escuras, anátropas, mesotestais, sem tégmem, exariladas e exalbuminosas. O embrião é axial, reto, total, branco, com cotilédones carnosos de reserva lipo-protéica, eixo hipocótilo-radícula curto e plúmula reduzida.