169 research outputs found
Migrainous infarction: a rare and often overlooked diagnosis
Migraine is a neurological entity and a well-known independent risk factor for cerebral infarction, which mostly afflicts the young female population. Researching focal neurological signs in this subset of the population with the diagnosis of a neurological ischemic event should always take into account the migraine as the etiology or as an associated factor. The etiology of central nervous system (CNS) ischemia is considerable. Migraine, although rare, also may be included in this vast etiological range, which is called migrainous infarction. In this setting, the diagnostic criteria required for this diagnosis is extensive. Herein, we present the case of a female adolescent who submitted to the emergency facility complaining of diplopia, dysarthria, and imbalance, which started concomitantly with a migrainous crisis with aura—a challenging clinical case that required extensive research to address all possible differential diagnose
Modelagem e simulação de um sistema de geração distribuída baseado na utilização de aerogeradores de pequeno porte
Este trabalho consiste na modelagem e simulação de um aerogerador de pequeno porte interligado à rede elétrica de distribuição secundária, ou seja, conectado à rede de baixa tensão. O sistema implementado computacionalmente é constituído pelos seguintes componentes: turbina eólica de 6 kW de potência elétrica nominal quando submetida a uma velocidade de vento de 12 m/s, gerador síncrono de ímã permanente trifásico, sistema de rastreamento do ponto de máxima potência, conversor CC-CC do tipo boost, inversor de frequência monofásico em ponte completa e filtro mitigador de distorçãoharmônica. Inicialmente, todos os elementos constituintes do aparato eólico-elétrico são descritos separadamente em detalhes. De posse de todos componentes do aerogerador, é feita a implementação em uma plataforma computacional para que se proceda a avaliação de desempenho. Nesta análise de performance é avaliada diversas grandezas elétricas, tais como: a potência ativa gerada e entregue à rede, os perfis das formas de ondas das tensões e correntes em alguns pontos do sistema de geração distribuída, além da análise do conteúdo harmônico da corrente elétrica antes e após o inversor de frequência
A Review of Classic Torque Control Techniques for Switched Reluctance Motors
In this chapter, the most relevant electronic torque control methods established in the current literature are addressed. The electronic torque control methods are divided into two technical topologies. The first one aims to control the average torque produced by the switched reluctance machine and is ideal for applications that require wide speed range of operation. The second topology enrolls the instantaneous torque production and is required in low torque ripple applications. Different torque control methods are addressed, for instance, direct average torque control, current profiling through torque sharing functions, direct torque control, and direct instantaneous torque control. Detailed information regarding the working principle and implementation of the methods is presented. Mathematical simulations are conducted in Matlab/Simulink® environment to elucidate the methods. Finally, a comparison of all addressed methods regarding the torque ripple minimization capabilities is presented
Cervical lymphadenopathy in childhood: nasopharyngeal carcinoma as a challenging diagnosis
Nasopharyngeal carcinoma (NPC) is a carcinoma that arises from the nasopharyngeal mucosa and differs from other head and neck carcinomas by its unique histologic, epidemiologic, and biologic characteristics. NPC is rare in most countries, especially Europe and North America. However, it has a high incidence in several regions of South China. The incidence variability of NPC, among different geographical and ethnic groups, indicates a combination of genetic susceptibility, infection by Epstein-Barr virus and environmental factors. NPC is classified into three histological subtypes according to the 1991 World Health Organization classification: squamous cell carcinoma, nonkeratinizing carcinoma, and basaloid squamous cell carcinoma. The symptoms of patients with NPC are related to the primary tumor site and the degree of dissemination. Therefore, patients can remain asymptomatic during a long period of time. Imaging exams and biopsy of the tumor mass generally are sufficient to establish the diagnosis. NPC is a rare disease among children. The authors report a case of a 12-year-old boy who sought medical attention complaining of a progressive growing tumoral mass on the right side of the neck. The computed tomography images of the head and neck and the histological examination of a cervical lymph node biopsy diagnosed a metastatic NPC
Migrainous infarction: a rare and often overlooked diagnosis
Migraine is a neurological entity and a well-known independent risk factor for cerebral infarction, which mostly afflicts the young female population. Researching focal neurological signs in this subset of the population with the diagnosis of a neurological ischemic event should always take into account the migraine as the etiology or as an associated factor. The etiology of central nervous system (CNS) ischemia is considerable. Migraine, although rare, also may be included in this vast etiological range, which is called migrainous infarction. In this setting, the diagnostic criteria required for this diagnosis is extensive. Herein, we present the case of a female adolescent who submitted to the emergency facility complaining of diplopia, dysarthria, and imbalance, which started concomitantly with a migrainous crisis with aura—a challenging clinical case that required extensive research to address all possible differential diagnose
Progressive multifocal leukoencephalopathy: a challenging diagnosis established at autopsy
Progressive multifocal leukoencephalopathy (PML) is a feared entity that occurs most frequently in conditions of extreme immunodeficiency. The diagnosis is often made long after the onset of symptoms due to the physicians’ unfamiliarity, and the unavailability of diagnostic tests in some medical centers. Although the incidence of PML is decreasing among HIV patients with the advent of highly active antiretroviral therapy (HAART), in Brazil this entity is the fourth highest neurological complication among these patients. The authors present the case of a middle-aged man who tested positive for HIV concomitantly with the presentation of hyposensitivity in the face and the right side of the body, accompanied by mild weakness in the left upper limb. The clinical features worsened rapidly within a couple of weeks. The diagnostic work-up pointed to the working diagnosis of PML after brain magnetic resonance imaging; however, the detection of the John Cunningham virus (JCV) in the cerebral spinal fluid was negative. HAART was started but the patient died after 7 weeks of hospitalization. The autopsy revealed extensive multifocal patchy areas of demyelination in the white matter where the microscopy depicted demyelination, oligodendrocytes alterations, bizarre atypical astrocytes, and perivascular lymphocytic infiltration. The immunohistochemistry was positive for anti-SV40, and the polymerase chain reaction of the brain paraffin-embedded tissue was positive for JCV. The authors highlight the challenges for diagnosing PML, as well as the devastating outcome of PML among HIV patients
Ethical attitude of accountants: recent evidence from a survey with students and accounting professionals under gender perspective
Escândalos envolvendo contadores e, consequentemente, a ética contábil, como os das empresas Enron, WorldCom, Quest, entre outras, têm destacado o papel da ética junto aos profissionais contábeis. Nestes episódios, as mulheres, em especial, tiveram um papel decisivo, pois Sherron Watkins e Cynthia Cooper foram as responsáveis por deflagrar os processos que culminaram com a falência da Enron e da WorldCom. A amostra utilizada é composta de 234 profissionais da área e 478 estudantes de Contabilidade de duas instituições de ensino superior do Paraná. O tópico abordado torna-se relevante, pois o papel das mulheres vem crescendo na sociedade como um todo. Estas, apesar de terem seus direitos reconhecidos tardiamente nas sociedades mais evoluídas, desempenham uma função cada vez mais relevante na sociedade atual. Foi possível inferir que as mulheres mostraram uma menor aceitabilidade para certos comportamentos do que os homens. Foram encontradas diferenças estatisticamente significantes em 9 (nove) das 25 (vinte e cinco) questões apresentadas.Scandals involving accountants and consequently the ethical accounting, as Enron, WorldCom, Quest and others have emphasized the role of ethics for professionals with accounting. In these episodes, women, in particular, played a decisive role, since Cynthia Cooper and Sherron Watkins were the "whistle blowers" that culminated with the bankruptcy of Enron and WorldCom. The sample consists of 234 accounting professionals and 478 accounting students from two institutions of higher education in the State of Paraná, Brazil. The topic addressed is relevant because the growing role of women in society as a whole. Despite of having their rights recognized belatedly in more developed societies, they play an increasingly important role in society today. It was possible to infer that women showed less acceptance for certain behaviors than men. Statistically significant differences were found in 9 (nine) out of 25 (twenty five) questions presented
Traumatic injury to the internal carotid artery by the hyoid bone: a rare cause of ischemic stroke
Central nervous system (CNS) ischemic events, besides being a common and devastating disease, are accompanied by severe disability and other morbidities. The cause of such events is not always that simple to diagnose, and among the young, a broad spectrum of possibilities should be considered. We present the case of a young man who presented two episodes of CNS ischemia with a 1 year gap between them, which occurred in the same situation while he was walking and carrying a heavy backpack. The second event first presented as a transient ischemic attack followed by a stroke the day after. The diagnostic work-up showed an indentation of the greater cornu of the hyoid bone over the internal carotid artery, which injured the media and intimal layers. At the arterial injury site, a micro thrombus was found, which explained the source of the embolic event to the CNS. The patient was operated on, and the procedure included the resection of the posterior horn of the hyoid bone, the resection of the injured segment of the internal carotid artery followed by carotid–carotid bypass with the great saphenous vein. The postoperative period and the recovery were uneventful as was the 5-month follow-up. We call attention to this unusual cause of stroke and present other cases reported in the literature
Femoral shaft fracture: reproducibility of AO-ASIF and Winquist classifications
OBJECTIVE: To evaluate inter-observer reproducibility of AO / ASIF and Winquist-Hansen classifications for shaft fractures of the femur in adults. METHODS: 50 anterior-posterior and profilelateral radiographs were randomly selected, of adult patients awith diaphyseal fracture of the femur. The radiographs were analyzed by 5 observers-a member of the Brazilian Society of Orthopedic Trauma, a radiologist and 3 residents. To assess the concordance between these classifications, we used the statistical index Kappa (K). RESULTS: In all analyses, we observed a statistically significant correlation coefficient between observers (p <0.05) and according to the criteria of Landis and Koch, they were ranked them as good (values of 0.61 to 0.80) or very good (values above 0.80). CONCLUSION: The AO rating and Winquist present a high rate of concordance between observers for shaft fractures of the femur in adults.OBJETIVO: Avaliar a reprodutibilidade interobservadores das classificações AO/ASIF e de Winquist para as fraturas diafisárias do fêmur no adulto. MÉTODOS: foram selecionadas aleatoriamente 50 radiografias de pacientes adultos portadores de fratura diafisária do fêmur nas incidências em antero-posterior e perfil. As radiografias foram analisadas por 5 observadores, sendo um membro da Sociedade Brasileira de Trauma Ortopédico, um radiologista, um residente do terceiro ano de Ortopedia e Traumatologia, um do segundo e um do primeiro. Para avaliar a concordância interobservadores destas classificações, foi utilizado o índice estatístico Kappa (K). RESULTADOS: Em todas as análises, observou-se um coeficiente de concordância entre observadores estatisticamente significativo (valor p < 0,05) e classificado como bom (valores de 0,61 a 0,80) ou muito bom (valores acima de 0,80), segundo os critérios de Landis e Koch. CONCLUSÃO: As classificações AO e Winquist apresentam alto índice de concordância interobservadores para as fraturas diafisárias do fêmur no adulto.Universidade Federal de Minas Gerais Hospitais Felício Rocho e da Baleia Departamento do Aparelho LocomotorUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaHospital Felício Rocho Serviço de Ortopedia e TraumatologiaUniversidade Federal de Minas Gerais Departamento do Aparelho LocomotorUNIFESP, EPMSciEL
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