987 resultados para sheath fold
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The radial magnetic field profile during implosion of a reversed field current sheath in a theta-pinch was investigated through local measurements and simulation of hybrid code. The actual profile was defined by Hermite interpolation polynomial through mean value of the field at discrete radial position of measurements. Simulation profile was provided by the numerical code with appropriate initial conditions. Classical and anomalous collision process were taken in account in the theoretical model. The results indicated that anomalous effects play major role during the implosion phase of current sheath in a slow rising theta pinch device.
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The ultrastructure of the ovariole sheath along the Diatraea saccharalis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles of myofilaments that are arranged parallel to the long axis of the cells; these myofilaments are apparently related to the contraction movements of the follicles within the ovariole. The acellular tunica propria, composed of finely filamentous material, is attached to the adjacent follicle cells by adhesive dense plates. Between the epithelial sheath and the tunica propria there is a population of lumen cells, with morphological features of secretory activity.
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The Araguaia-Tocantins geosuture, which separates the Araguaia Fold Belt (AFB) from the Archean Amazonian Craton, was active in the late Middle Proterozoic. The Baixo Araguaia Supergroup was deposited, consisting of the Estrondo Group (lower quartzites with intercalated schists), Xambioá Formation (schists), and Canto da Vazante Formation (upper feldspathic schists); and the Tocantins Group consisting of the Couto Magalhaës Formation (phyllites, quartzites, slates, limestones, and metacherts) and Pequizeiro Formation (upper chlorite schists); and associated mafic-ultramafic bodies. The deformational history includes four regional phases of deformation within this supracrustal sequence: recumbent folds with vergence to the west; refolding with a N-S trend; an intense crenulation episode; and late thrusting from east to west. Metamorphism is of intermediate or intermediate-high pressure type with garnet, biotite, chlorite, and sericite isograds succeeded by a slightly or non-metamorphosed zone, from east to west. Rocks surrounding sparse gneissic-cored domes contain isograds of staurolite, kyanite, and fibrolite. These isograds are believed to be associated with the 1100 Ma Uruaçuano event. The Brasiliano Orogeny strongly affected the AFB with displacements due to transcurrent reactivation of great and old faults of the basement, slight folding in the supracrustal sequence, intrusion of small granite bodies, and development of domes with associated normal faults. The area underlain by the Estrondo Group was uplifted at this time, causing the deposition of the Rio das Barreiras polymictic conglomerate of the central area. K-Ar and Rb-Sr analyses date this thermo-tectonic event at 550 ± 100 Ma. The Archean basement is exposed in the cores of domes as a granite-gneiss association, the Colméia complex, which shows thermo-tectonic features that may be interpreted as polycyclic imprints (Jequié, Transamazonian?, Uruaçuano, and Brasiliano Events). © 1989.
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Termino-lateral neurorrhaphies have been used up to the beginning of this century. After this period, they have no longer been reported. We tested the efficacy of a new type of latero-terminal neurorrhaphy and evaluated the role of the epineural sheath. A group of 10 rats had the fibular nerve sectioned and the distal ending was sutured to the lateral face of the tibial nerve without removing the epineurium. All experiments were made on the right side, the left one remaining untouched in half of the animals of each group. The other half were denervated by sectioning and inverting the endings of the fibular nerves. In this way, tibial cranial muscles were either normal or denervated in the left side and reinnervated through latero-terminal neurorrhaphy in the right side. After 7.7 months, the animals were subjected to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. A response of the tibial cranial muscle was obtained in 75% of the animals. The distal ending of the fibular nerve showed an average of 498 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (mu 2):841.30 for M2n and 1798.33 for M2d. We concluded that the termino-lateral neurorrhaphy was functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The presence of the epineurium was no impediment to axonal regeneration or to the passage of electrical stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
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Laryngeal Electromyography (LEMG) is a diagnostic test commonly used in patients with vocal fold movement disorder The aim of this study is to describe LEMG in patients with vocalfold immobility. A total of 55 dysphonic patients with vocal fold immobility diagnosed by laryngeal endoscopy were grouped according to probable clinical cause: 1) unknown; 2) traumatic; or 3) tumoral compression. They were submitted to LEMG by percutaneous insertion of concentric needle electrode. LEMG was conclusive in all patients and showed a majority with peripheral nerve injury. LEMG diagnosed peripheral nerve damage in 25 group 1, 12 group 2, and 11 group 3 patients. LEMG was normal in 4 patients, suggesting cricoarytenoid joint fixation. Central nervous system disorders was suggested in 2 and myopathic pattern in 1. As the major cause of vocal fold immobility is peripheral nerve damage, LEMG is an important test to confirm diagnosis.
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This letter describes a novel algorithm that is based on autoregressive decomposition and pole tracking used to recognize two patterns of speech data: normal voice and disphonic voice caused by nodules. The presented method relates the poles and the peaks of the signal spectrum which represent the periodic components of the voice. The results show that the perturbation contained in the signal is clearly depicted by pole's positions. Their variability is related to jitter and shimmer. The pole dispersion for pathological voices is about 20% higher than for normal voices, therefore, the proposed approach is a more trustworthy measure than the classical ones. © 2007.
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A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.
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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Objective. To compare the dynamic viscosity (DV) of superficial layer of temporalis fascia (SLTF) with that of other biological tissues traditionally used for vocal fold implants to treat vocal fold rigidity. Study Design. Experimental. Method. Measurement of DV of samples of SLTF, deep layer of temporalis fascia (DLTF), and abdominal fat of 12 cadavers. Results. DV values of the different samples were presented in the following increasing order: SLTF, DLTF, and abdominal fat. There was statistical difference between the samples. Conclusion. DV of SLTF is lower than of other tissues tested.