584 resultados para Bundles
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The objective of the work was to accomplish an anatomical and ultrastructural study of mature leaf of Cymbopogon citratus (Poaceae) and analyze the essential oil through Gas Chromatography (GC). For the anatomical study, the material was fixed in FAA, followed bytheethyl dehydration and infiltration of the material in synthetic resin. For the ultrastructural study, the material was fixed and Kamovsky, dehydrated in acetone, dried to the critical point and metallized. For the analysis in GC, the essential oil it was obtained by steam distillation of leaves and analyzed by Gas Chromatography. Through the anatomical study it was observed that the faces of mesophyll are distinctly, the bulliform cells occupy the adaxial surface of the leaf and in the medium region are situated the biggest vascular bundles involved by sclerenchymatous hem with extensions reaching both epidermis. Between the biggest vascular bundles are observed three to five small vascular bundles, linkage only in the abaxial epidermis. Shortly, pointed and unicellular structures, called prickle-hair, had been observed inserted above the veins and micro-hair, that they consist of a long basal cell and an oval distal cell, that are located between the regions of vascular bundles. The chromatogram sample shows that the analyzed essential oil presented three majority components, responsible for 87% of the relative composition of the oil. These components are monoterpenos, justifying the strong smell of the essential oil.
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The purpose of this study was to evaluate the host response of a human and a porcine derived acellular dermal tissue (ADT) implanted in the subcutaneous tissue of a rat model. Two subcutaneous pockets were surgically created along the dorsal midline of 25 rats (5 rats/group). The human ADT was placed superiorly and the porcine ADT, inferiorly. The animals were sacrificed at 07, 15, 30, 60 and 180 postoperative days (PO) and the ADTs and surrounding soft tissues were assessed for ultrastructural evaluation by transmission electron microscopy. The ultrastructural findings were similar in both materials. Normal collagen and elastic fibers bundles were observed during all experimental moments, as well as macrophages presenting cytoplasmic enlargements digesting cellular portions after 15 PO. From 30 until 180 PO, vacuolar structures filled with an amorphous, electron-transparent substance, were present inside and outside the fibroblasts. Both human and porcine ADT showed similar pattern of ultrastructural response when implanted in the subcutaneous tissue of rats. The porcine ADT appears as a good alternative to be used as a biomaterial.
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The structure of the spermatheca was investigated in specimens of five termite families with the aid of light microscopy. In longitudinal section, the spermatheca of Zootermopsis nevadensis (Termopsidae) showed the shape of an umbrella with a secretory portion and duct. The other termite species, which belong to the families Kalotermitidae, Serritermitidae, Rhinotermitidae and Termitidae showed a spermatheca constituted only by the secretory portion. This structure was an elongate, fingerlike tube with a recurved and blind extremity. The spermatheca wall was composed of a single epithelium formed by class 3 secretory cells with a lumen lined by cuticle. The cuticle was thin and smooth or thick with digitiform projections in the species examined. All the termite females showed bundles of musculature outside of the spermatheca.
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Achyrocline alata occurs in a dense and low vegetation in Mato Grosso do Sul State, Brazil and it has been studied under physical-chemical and yield aspects, being scarce anatomical data. The present work has as objective the study of the aerial vegetative axis. Stem is cylindrical and hairy, having five wings, which are arisen from their leaves. The blade shows the presence of uniseriate epidermis, which is covered by the cuticle of variable thickness; and non-glandular and glandular trichomes. The non-glandular trichomes are uniseriate and multicellular and have their apex cell in whip form, while the glandular trichomes are multicellular, uniseriate or biseriate. The mesophyll is dorsiventral with uni-stratified palisade parenchyma in most of the cases and lacunal parenchyma formed by three to four layers of irregular cells. Only one collateral vascular bundle occurs in the midvein. Stem in transversal section is covered by epidermis with trichomes similar to leaves; the cortex is constituted by a discontinuous area of angular collenchyma, which is followed by chlorophyll parenchyma. Vascular cylinder that is delimited by pericycle shows vascular bundles of collateral type. In the secondary structure, the periderm is originated from epidermal and subepidermal tissues. In vascular region, the fascicular cambium differs into secondary xylem and phloem, while interfascicular cambium produces sclerenchymatous tissue.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The high potential for the exploitation of capybara requires information about its digestory morphophysiology, to improve nutritional handling. In the present study, gross anatomy, light microscopy and body and intestine lengths of 25 capybaras were evaluated. The minimum and maximum small intestine lengths for females and males were, respectively, 441 cm and 1734 cm, and 355 cm and 1123 cm. These values position the capybara between canine and swine intestinal lengths. The ratio between small intestine and body length was 12:1, without differences between sexes. There were no statistically significant differences between sexes for each part of small intestine. Correlation between length of each small intestine segment and body length was positive, and statistically significant only for the duodenum. The small intestine wall was formed by mucosa, submucosa, muscular and serosa. The mucosa presented intestinal and duodenal glands, of mucosal and serosal types, respectively. The mucosa muscular layer consisted of two distinct layers in the jejunum and ileum, and a thin and single layer in the duodenum. The submucosa, formed by moderate dense connective tissue, didn't show glands. The fiber bundles of the internal layer of muscular tunic were helicoidally arranged. The gross anatomy of the capybara small intestine was similar to canine and swine intestines. Microscopically, however, subtle differences can be identified in the submucosa and internal muscular tunics.
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New comparative data are presented on the reproductive morphology and anatomy of two genera closely related to grasses, Flagellaria and Joinvillea, in which the flowers are superficially similar, especially in stamen morphology. This investigation demonstrates some anatomical differences between the two genera. For example, both genera depart from the 'typical' condition of tepal vasculature (three-traced outer tepals and one-traced inner tepals): in Flagellaria, each tepal receives a single vascular bundle and, in Joinvillea, each tepal is supplied by three vascular bundles. Joinvillea possesses supernumerary carpel bundles, as also found in the related family Ecdeiocoleaceae, but not in Flagellaria or grasses. In the anther, the tapetum degenerates early in Flagellaria, and is relatively persistent in Joinvillea, in which the pollen grains remain closely associated with the tapetum inside the anther locule, indicating a correlation between peripheral pollen (a feature that is common in grasses) and a persistent tapetum. This study highlights the presence of a pollen-tube transmitting tissue (PTTT) or solid style in the gynoecium of Flagellaria, as also in many Poaceae, but not in Joinvillea or Ecdeiocoleaceae. We speculate that the presence of a PTTT could represent one of the factors that facilitated the subsequent evolution of the intimately connected gynoecia that characterize grasses. © 2012 The Linnean Society of London.
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Malignant peripheral nerve sheath tumors (MPNST) involving spinal nerve roots are uncommon in dogs. A nine-year old, intact, mixed-breed dog, demonstrated clinical signs of incoordination in the pelvic limbs and micturition for approximately one week. Clinical examination revealed proprioceptive deficits and bilateral patellar hyperreflexia. During exploratory celiotomy a mass was observed adhered to the lumbar vertebral segments. Medical therapy was initiated, but neurological signs were progressive, and the owner opted for euthanasia. Gross examination showed that the mass in the abdominal cavity was attached to the lumbar segments L3 and L4, causing bone lysis in L3, but showed no tumor invasion into the spinal canal. Microscopic features were characterized by prominent proliferation of ovoid and fusiform cells with poorly defined cytoplasm arranged in interlacing bundles and concentric whorls. The cells were embedded in a delicate to moderate collagenous stroma and moderate anisokariose and high mitotic activity were noted. The immunohistochemical assay showed positive staining for GFAP, S-100 protein and vimentin, and negative staining for factor VIII, α-actin and citokeratine. The definitive diagnosis of malignant peripheral nerve sheath tumor was made on the basis of the histological and immunohistochemical findings.
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Bulbophyllum section Micranthae comprises 12 species of rupicolous or epiphytic orchids occurring in forests or in open rocky fields in Cerrado/Atlantic Forest ecotones throughout South America. We examined the leaf anatomy of 14 species and compared them with molecular data (nrITS) in phylogenetic analyses. The leaves of Bulbophyllum section Micranthae are characterised by uniseriate epidermis, with periclinal external cell wall thicker than the internal, presence of epicuticular wax, stomata present only on the abaxial surface with suprastomatic chambers, and collateral vascular bundles associated with sclerenchyma fibres. Some of these characters are shared with other rupicolous Orchidaceae species, demonstrating adaptive convergence in xeromorphic habitats. We found some anatomical characteristics with phylogenetic value. Bulbophyllum section Micranthae can be separated into two lineages: those with needle-like leaves, or flat leaves. The analyses show that anatomical characters as well as molecular data may contribute to the development of phylogenetic hypotheses. © 2013 Botanical Society of Sao Paulo.
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The family Malpighiaceae is considered monophyletic, but the intra-family classification is conflicting. Analyses of floral vasculature allow the identification of reductions, connations and adnations and can even reveal evolutionary steps prior to current floral morphology. The present work analysed the floral vasculature of Janusia mediterranea, Mascagnia cordifolia and Tetrapterys chamaecerasifolia using material processed by traditional methods for light microscopy. A general pattern was observed of three bundle traces supplying each sepal and one trace per petal and stamen; Mascagnia is an exception, as its eglandular sepal has only a median trace but shares lateral traces with adjacent sepals. No dorsal traces are emitted to the carpels; however, three intercarpellary complexes are emitted that divide into six ventral bundles, supplying the ovule. Mascagnia demonstrates connation between the anterior and adjacent sepal glands; reductions of the anterior sepal glands were registered in Tetrapterys and Janusia. This work reveals two distinct processes for gland loss in non-related groups of the family that resulted in similar present appearances. Our evaluation of the number of calyx glands and the processes of glandular loss in species with less than ten glands improves our understanding of the evolution of calyx glands in Malpighiaceae. © 2013 Elsevier GmbH.
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Paepalanthus sect. Diphyomene comprises 18 species with a convoluted taxonomic history. Aiming to correlate anatomical structures with the systematics of this group and its relatives, we studied the anatomy of scapes, reproductive axis bracts, and leaves of 20 Paepalanthus species. Bracts and leaves show differences in epidermal cell thickening; mesophyll width; vascular bundle arrangement; presence or absence of a hypodermis; types of cells in the vascular bundle sheath extensions; margin shape and composition; and presence or absence of aquiferous parenchyma. Scapes differ in contour, rib number, and pith size. Some diagnostic characters found are presence of aquiferous parenchyma and absence of vascular bundle sheath extensions in leaves of P. urbanianus; vascular bundles decreasing in size towards the margin of leaves and bracts, and scapes with a triangular contour in P. flaccidus; scapes with nine ribs in P. acanthophyllus and ten in P. macer. All anatomical features are summarized in tables. These results aid in the identification and characterization of the species of P. sect. Diphyomene. They also support the current section circumscription, reinforcing the relevance of the anatomical characters in order to define natural groups. © 2012 The New York Botanical Garden.
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The recalcitrance in grasses varies according to cell type and maturation. The origin of the recalcitrance in different regions from sugar cane internodes with varied lignin contents was evaluated. The efficiency of enzymatic hydrolysis was correlated with the chemical, micromorphological and microspectrophotometric characteristics of the samples. The internodes of three sugar cane hybrids were dissected into four different fractions. The outermost fraction and the rind were the most recalcitrant regions, whereas the pith-rind interface and the pith were less recalcitrant. Cellulose conversion reached 86% after 72h of enzymatic digestion of the pith from the hybrid with the lowest lignin content. There was an inversely proportional correlation between the area occupied by vascular bundles and the efficiency of cellulose hydrolysis. High cellulose and low lignin or hemicellulose contents enhanced the efficiency of enzymatic hydrolysis of the polysaccharides. The critical evaluation of the results permitted to propose an empirical parameter for predicting cellulose conversion levels that accounts for the positive effect of high cellulose and low lignin plus hemicellulose and the detrimental effect of abundant vascular bundles. The cellulose conversion levels fit well to this calculated parameter, following a second order polynomial with an r2 value of 0.96. © 2013 Elsevier B.V.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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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)