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Search Results: 1 - 10 of 223748 matches for " Américo C.; "
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Frequency-Domain Receivers for Rate-1 Space-Time Block Codes  [PDF]
Mário Marques da Silva, Rui Dinis, Américo M. C. Correia
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.29098
Abstract: This paper considers iterative frequency-domain receivers for block transmission techniques with rate-1 Space Time Block Coding (STBC) for two and four transmit antennas using both Orthogonal Frequency Division Multiplexing (OFDM) and Single-Carrier (SC) schemes. The proposed receiver includes an interference canceller which enhances the performance of the non-orthogonal STBC scheme with 4 transmit antennas, allowing performances close to those of orthogonal codes. Our performance results show that combining STBC with block transmission techniques allows excellent performances.
Os 50 anos de uso do horm?nio adrenocorticotrófico (ACTH) no Tratamento da Síndrome de West: revis?o de literatura e protocolo da UNIFESP
Gomes, Maria Durce Costa;Garzon, Eliana;Sakamoto, Américo C.;
Journal of Epilepsy and Clinical Neurophysiology , 2008, DOI: 10.1590/S1676-26492008000100007
Abstract: introduction: it is extensively discussed in the literature the efficacy of acth in west syndrome (ws) as well, dosage, best protocols and side effects. objective: analyze and discuss the most recent and relevant publication related to acth in patients with ws. methodology: literature publication was selected from medline and pubmed between 1997 to 2007 using the following key words: "acth" and " west syndrome". results: 96 titles were referral at medline and 158 at pubmed. 22 were selected and previous studies with special relevance were also included. conclusions: there are evidences that acth probably has efficacy for immediately control of spasms and hypsarrhythmia. there is no evidence about the efficacy of acth in long term concerning seizures control and prevent delayed developmental).
A quality and cost approach for welding process selection
Silva, César Rezende;Ferraresi, Valtair Antonio;Scotti, Américo;
Journal of the Brazilian Society of Mechanical Sciences , 2000, DOI: 10.1590/S0100-73862000000300002
Abstract: the aim of this work was to propose, apply and evaluate a methodical approach to select welding processes in a productive environment based on market requirements of quality and costs. a case study was used. the welds were carried out in laboratory, simulating the joint conditions of a manufacturer and using several welding processes: smaw, gtaw, pulsed gtaw, gmaw with co2 and ar based shielding gases and pulsed gmaw. for quality analysis geometrical aspects of the beads were considered and for cost analysis, welding parameters and consumable prices. quantitative indices were proposed and evaluated. after that, evaluation of both quality and costs was done, showing to be possible to select the most suitable welding process to a specific application, taking into account the market conditions of a company.
A quality and cost approach for welding process selection
Silva César Rezende,Ferraresi Valtair Antonio,Scotti Américo
Journal of the Brazilian Society of Mechanical Sciences , 2000,
Abstract: The aim of this work was to propose, apply and evaluate a methodical approach to select welding processes in a productive environment based on market requirements of Quality and Costs. A case study was used. The welds were carried out in laboratory, simulating the joint conditions of a manufacturer and using several welding processes: SMAW, GTAW, pulsed GTAW, GMAW with CO2 and Ar based shielding gases and pulsed GMAW. For Quality analysis geometrical aspects of the beads were considered and for Cost analysis, welding parameters and consumable prices. Quantitative indices were proposed and evaluated. After that, evaluation of both Quality and Costs was done, showing to be possible to select the most suitable welding process to a specific application, taking into account the market conditions of a company.
Hemimegalencephaly and epilepsy: an overview
Terra-Bustamante, Vera C.;Machado, Hélio R.;Sakamoto, Américo C.;
Journal of Epilepsy and Clinical Neurophysiology , 2006, DOI: 10.1590/S1676-26492006000300010
Abstract: introduction: cerebral cortical development is a highly complex process influenced by environmental, genetic and functional abnormalities. hemimegalencephaly (hme) is a rare brain malformation that involves overgrowth of one hemisphere. clinically macrocephaly, mental retardation, contralateral hemiparesis, hemianopsia and intractable epilepsy may be present. diagnosis is mainly done with image and clinical findings. mri typically reveals an enlarged cerebrum involving at least one lobe, with a thickened cortex; broad gyres; abnormal gray-white matter differentiation with abnormal sign; neuronal heterotopia, ventricle asymmetry, and basal ganglia and internal capsule abnormalities. electroencephalographic abnormalities usually involve the affected hemisphere, with an asymmetric amplitude of the normal, age-related rhythms; slow, rhythmic or fast activity and multifocal unilateral or bilateral high-amplitude spikes and spike-wave complexes. histopathologic changes include abnormal gyrification, with loss of cortical lamination, neuronal heterotopia, gliosis, large bizarre neurons and balloon-cells. the presence of highly refractory seizures in patients with hme is an important factor to consider epilepsy surgery in these patients. methods: multiple surgical techniques are actually being used for hemispheric disconnection. we discuss here the main surgical techniques that are used for hemispheric disconnection. conclusions: postsurgery outcome for hme may be not as good as that for focal lesions with approximately 40% of patients being seizure free, but the main indication for surgery in these patients may be preventing additional cognitive injury and developmental delay. surgical complications are observed in most of the series of patients with hme submitted to hemispheric surgery. minimal resections may contribute do diminish surgical complications.
Sudden death in a child with epilepsy: potential cerebellar mechanisms?
Scorza, Fulvio A.;Terra, Vera C.;Arida, Ricardo M.;Sakamoto, Américo C.;Harper, Ronald M.;
Arquivos de Neuro-Psiquiatria , 2011, DOI: 10.1590/S0004-282X2011000500024
Abstract: epilepsy is the most common neurological disorder in humans. people with epilepsy are more likely to die prematurely than those without epilepsy, with the most common epilepsy-related category of death being sudden unexpected death in epilepsy (sudep). the central mechanisms underlying the fatal process remain unclear, but cardiac and respiratory mechanisms appear to be involved. recently, cerebellar, thalamic, basal ganglia and limbic brain structures have been shown to be implicated in respiratory and cardiac rate regulation. we discuss here the potential mechanisms underlying the fatal process, with a description of cerebellar actions likely failing in that sudep process.
Vasculopatia cerebral na síndrome do anticorpo antifosfolípide primária: relato de dois casos
Siqueira Neto, José Ibiapina;Santos, Antonio C.;Fábio, Soraia R. Cabette;Sakamoto, Américo C.;
Arquivos de Neuro-Psiquiatria , 1996, DOI: 10.1590/S0004-282X1996000400017
Abstract: the antiphospholipid antibodies are associated with a large number of neurologic syndromes, cerebral infarct (ci) being the most common of them. in these cases the pathogenesis of the ci is poorly understood and remains controversial; however, the existence of a vasculopathy is indubitable. we report the cases of two young patients with ci and diagnosis of primary antiphospholipid syndrome who were submitted to cerebral angiograms, and one of them to necropsy. in one case the angiographic findings were similar to those of vasculitis in intracranial vessels. in the other case we observed obstruction in internal carotid artery at the angiography that looked like thrombosis in situ; at necropsy we found non-atherosclerotic obstruction in coronary arteries. in summary, is the primary lesion vasculitis, thrombosis, or both? these cases ilustrate the discussion and demonstrate that vasculitic mechanisms may be involved in the vasculopathy of primary antiphospholipid syndrome eventhough trombosis occur more frequently.
Anticorpos antifosfolípides em 66 pacientes com infarto cerebral entre 15 e 40 anos
Siqueira Neto, José Ibiapina;Santos, Antonio C.;Fábio, Soraia R. Cabette;Sakamoto, Américo C.;
Arquivos de Neuro-Psiquiatria , 1996, DOI: 10.1590/S0004-282X1996000400006
Abstract: the antiphospholipid antibodies (apls) are a heterogenous group of immunoglobulins that have been related with alterations in blood coagulability in recent years. patients with elevated titers of these antibodies have a high probability to develop thrombotic events, including cerebral infarct (ci). the tests currently used to detect these antibodies are the lupus anticoagulant and elisa for anticardiolipin antibodies which have a larger proportion of positivity among young patients with ci. in our study we tested 66 patients with cerebral infarcts whose ages ranged from 15 to 40 years for the presence of lupus anticoagulant and anticardiolipin antibodies. the results showed that eleven (16.65%) patients were positive for apls and three (4.55%) of them fulfilled the diagnostic criteria for primary antiphospholipid syndrome. these data point out to the importance of investigating apls in young patients with ci and its high prevalence in this group compared with healthy population.
Infartos cerebrais em pacientes jovens relacionados a deficiência de anticoagulantes naturais proteína C e proteína S
Siqueira Neto, José Ibiapina;Santos, Antonio C.;Fábio, Soraia R. Cabette;Sakamoto, Américo C.;
Arquivos de Neuro-Psiquiatria , 1996, DOI: 10.1590/S0004-282X1996000400007
Abstract: the possible etiologies of cerebral infarcts (ci) in young patients differ from those in the older stroke population. recently, deficiencies of fibrinolytic factors emerged as an important etiology of stroke in the young population. the literature has emphasized the diagnosis of such conditions especially in stroke cases of undetermined etiology and with history of recurrent thrombosis. we carried out a research on the serum level of protein c, protein s, and antithrombin iii in young patients, between 15 and 40 years, with ci of undetermined cause after application of a standard protocol. three patients had low levels of these proteins; two had protein c deficiency, and one protein s deficiency. none of them had antithrombin iii deficiency. we conclude that systematic investigation of such causes of cerebral infarct will reduce the group of undetermined strokes, and will open the possibility of prophylactic treatment in a non-negligible group of patients.
FIRST RECORDS OF OCTOCORALLIA (CNIDARIA: ANTHOZOA) TO THE CAPE HORN BIOSPHERE RESERVE, MAGELLAN REGION, CHILE PRIMEROS REGISTROS DE OCTOCORALLIA (CNIDARIA: ANTHOZOA) PARA LA RESERVA DE BIOSFERA CABO DE HORNOS, REGION MAGALLáNICA, CHILE
César Cárdenas,Leen van Ofwegen,Américo Montiel,Dirk Schories
Anales del Instituto de la Patagonia , 2008,
Abstract:
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