226 research outputs found
Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions
OBJECTIVES: Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS: A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS: In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION: Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence
Partial epilepsy: A pictorial review of 3 TESLA magnetic resonance imaging features
Epilepsy is a disease with serious consequences for patients and society. In many cases seizures are sufficiently disabling to justify surgical evaluation. In this context, Magnetic Resonance Imaging (MRI) is one of the most valuable tools for the preoperative localization of epileptogenic foci. Because these lesions show a large variety of presentations (including subtle imaging characteristics), their analysis requires careful and systematic interpretation of MRI data. Several studies have shown that 3 Tesla (T) MRI provides a better image quality than 1.5 T MRI regarding the detection and characterization of structural lesions, indicating that high-field-strength imaging should be considered for patients with intractable epilepsy who might benefit from surgery. Likewise, advanced MRI postprocessing and quantitative analysis techniques such as thickness and volume measurements of cortical gray matter have emerged and in the near future, these techniques will routinely enable more precise evaluations of such patients. Finally, the familiarity with radiologic findings of the potential epileptogenic substrates in association with combined use of higher field strengths (3 T, 7 T, and greater) and new quantitative analytical post-processing techniques will lead to improvements regarding the clinical imaging of these patients. We present a pictorial review of the major pathologies related to partial epilepsy, highlighting the key findings of 3 T MRI
Tropical Fruit Pulps: Processing, Product Standardization and Main Control Parameters for Quality Assurance
ABSTRACT Fruit pulp is the most basic food product obtained from fresh fruit processing. Fruit pulps can be cold stored for long periods of time, but they also can be used to fabricate juices, ice creams, sweets, jellies and yogurts. The exploitation of tropical fruits has leveraged the entire Brazilian fruit pulp sector due mainly to the high acceptance of their organoleptic properties and remarkable nutritional facts. However, several works published in the last decades have pointed out unfavorable conditions regarding the consumption of tropical fruit pulps. This negative scenario has been associated with unsatisfactory physico-chemical and microbiological parameters of fruits pulps as outcomes of little knowledge and improper management within the fruit pulp industry. There are protocols for delineating specific identity and quality standards (IQSs) and standardized good manufacturing practices (GMP) for fruit pulps, which also embrace standard operating procedures (SOPs) and hazard analysis and critical control points (HACCP), although this latter is not considered mandatory by the Brazilian legislation. Unfortunately, the lack of skilled labor, along with failures in complying established protocols have impaired quality of fruit pulps. It has been necessary to collect all information available with the aim to identify the most important hazards within fruit pulp processing lines. Standardizing methods and practices within the Brazilian fruit pulp industry would assurance high quality status to tropical fruit pulps and the commercial growth of this vegetal product towards international markets
Etanol from water hyacinth: A preliminary study of chemical pretreatment and enzymatic hydrolysis / Etanol de aguapé: um estudo preliminar de pré-tratamento químico e hidrólise enzimática
Considered a perennial plant, abundantly available, biodegradable and without competing with agricultural crops, the water hyacinth fulfills criteria considered necessary for biofuels production. The feasibility of producing ethanol from different pretreatments, in the liquor and in its broth after enzymatic hydrolysis, is investigated in this work. Only the liquor from the acidic pretreatment and after detoxification fermented well. An efficiently enzymatic hydrolysis occurred when the acidic and alkaline pretreatment were used, showing the action of these processes in the disruption of lignocellulose matrix, reaching higher sugars solubilization and, consequently, higher fermentation capacity
Parameters used to determine the diffuse pollution index (IQApd) using the method of cooperative game theory
The present work presents the methodology for obtaining the parameters and weights of the Water Quality Index of the
Urban Surface Drainage for the Anhumas riverside, located in the city of Campinas, São Paulo. It is a method developed for
a mixed system of urban drainage and wastewater depletion. This index will indicate the existence or not of the diffuse pollution contained in the urban surface runoff, determining the existence of a pollutant load. In this way, they were studied
to determine which parameters and weights would be part of the Water Quality Index for Diffuse Pollution (IQApd), which
will indicate the water quality of the urban surface runoff, at the exact moment of its collection. This number is acquired
from the aggregation of physical-chemical, bacteriological and chemical data by means of specific methodologies. The
advantage of this methodology is due to the fact that it synthesizes in only a number of parameters, facilitating its interpretation when compared with individual indicators and with little expressiveness
APLICAÇÃO DE MÉTODO ANALÍTICO PROBABILÍSTICO PARA O PLANEJAMENTO DE RESERVATÓRIOS DE DETENÇÃO: Application of probabilist analytical method for planning detention reservoirs
The present work has the objective of presenting a rapid calculation methodology for the pre-dimensioning of storage reservoirs of the drainage water for urban macro drainage planning. The Probabilistic Analytical Model, methodology used, is based on the exponential distributions of probabilities of the total volume, duration, intensity and times of rainfall events. Starting from these premises, the calculation of the necessary parameters for its application is carried out in a simple and fast way through formulas obtained by the equations of the probability theory. This model presents a very simple mathematical tool, reducing the computational time, besides offering the possibility of expedited simulations, using the hydrological parameters of the region under study, requiring only a small historical series of rainfall data, without the need of surveying the fluvial-morphological information of the basins. This method would be used in the urban planning and / or planning phase of the macro drainage system, since it is a method developed for a mixed urban drainage system. The methodology was applied to the Anhumas creek in Campinas, a very urbanized urban basin, whose results were excellent. The volumes thus determined made it possible to determine the potential sites to be implemented, due to the minimum area and volume requirements, without the need to collect other information, which is necessary for the preparation of a basic or executive project, used in the urban drainage planning phase.O presente trabalho tem como objetivo apresentar uma metodologia de cálculo rápido para pré-dimensionamento de reservatórios de armazenamento das águas do escoamento pluvial para planejamento da macrodrenagem urbana. O Modelo Analítico Probabilístico, metodologia utilizada, é fundamentado nas distribuições exponenciais de probabilidades do volume total, da duração, da intensidade e dos tempos de inter eventos das chuvas. Partindo-se destas premissas, o cálculo dos parâmetros necessários para sua aplicação é realizado de forma simples e rápida por meio de fórmulas obtidas pelas equações da teoria das probabilidades. Este modelo apresenta um ferramental matemático bem simples, reduzindo o tempo computacional, além de oferecer a possibilidade de simulações expeditas, utilizando os parâmetros hidrológicos da própria região em estudo, necessitando apenas de uma pequena série histórica de dados pluviográficos, sem a necessidade de levantamento das informações flúvio-morfológicas das bacias. Este método seria utilizado na etapa de planejamento urbano e/ou planejamento do sistema de macrodrenagem, pois é um método desenvolvido para um sistema misto de drenagem urbana. A metodologia foi aplicada ao Ribeirão das Anhumas em Campinas, uma bacia urbana bastante urbanizada, cujos resultados foram excelentes. Os volumes assim determinados permitiram determinar os potenciais locais a serem implementados, devido às necessidades mínimas de área e de volumes, sem a necessidade do levantamento de outras informações, que são necessárias para a elaboração de um projeto básico ou executivo
Device for positioning surgical tool in the body of patient
The present disclosure relates to a device for positioning and/or orienting, in the body of a patient, a surgical tool carried by a tool-holder, including a platform capable of being placed on the body of the patient, an orientable carrier, at least one part of which is rigidly connected to the tool-holder, means for guiding the orientable carrier rotationally relative to the platform in two directions of a plane parallel to the platform, at least 2 pneumatic actuators which engage with the orientable carrier such that a variation in pressure of at least one of the pneumatic actuators causes the orientable carrier to rotate in the first direction and/or the second direction, in which the pneumatic actuators are volumes that can deform in a predetermined direction as a function of the internal pressure
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