Abstract Background Anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody-associated disease (MOGAD) is an immune-mediated neurological disorder with a broad spectrum of clinical presentation that is often difficult to distinguish from other demyelinating diseases, such as multiple sclerosis and neuromyelitis optica spectrum disorder. Objective To describe the clinical and paraclinical characteristics of MOGAD in a Brazilian tertiary center. Methods We retrospectively reviewed the records of adult and pediatric patients who tested positive for anti-MOG antibodies and presented with clinical and radiological diseases compatible with MOGAD. Results Forty-one patients (10 children) were included: 56% female, 58% Caucasian, mean age at onset 31 years (range 6-64), with a mean disease duration of 59.6 months (range 1-264 months). The most frequent onset presentation was optic neuritis (68%), acute disseminated encephalomyelitis (ADEM, 12%), and myelitis (10%). A monophasic disease course was observed in 49%. EDSS median was 2.1 at the last visit. Most patients (83%) were under continuous immunosuppressive treatment. Azathioprine was the first-line treatment in 59%. In all ADEM cases, conus, and root involvement was radiologically observed on MRI. Conclusion Brazilian MOGAD patients presented with a similar spectrum of previously reported MOGAD phenotypes. Conus and spinal root involvement seems to be frequently present in MOGAD-ADEM and could serve as radiologic characteristics of this clinical entity.

Resumo Antecedentes A doença associada ao anticorpo da glicoproteína da mielina de oligodendrócitos (anti-MOG; MOGAD) é uma doença neurológica imunomediada com um amplo espectro de apresentações clínicas que muitas vezes é difícil de distinguir de outras doenças desmielinizantes, como a esclerose múltipla e o distúrbio do espectro da neuromielite óptica. Objetivo Descrever as características clínicas e paraclínicas da MOGAD em um centro terciário brasileiro. Métodos Revisamos retrospectivamente os prontuários dos pacientes adultos e pediátricos que testaram positivos para anticorpos anti-MOG e apresentaram um quadro clínico e radiológico compatível com MOGAD. Resultados Quarenta e um pacientes (10 crianças) foram incluídos: 56% do sexo feminino, 58% caucasianos, idade média de início da doença foi 31 anos (intervalo de 6-64), com duração média da doença de 59,6 meses (intervalo de 1-264 meses). A apresentação inicial mais frequente foi neurite óptica (68%), seguida pela encefalomielite disseminada aguda (ADEM, 12%) e mielite (10%). Um curso monofásico da doença foi observado em 49%. EDSS foi de 2,1 na última visita. A maioria dos pacientes (83%) estava sob tratamento imunossupressor contínuo. Azatioprina foi o tratamento de primeira linha em 59%. Em todos os casos de ADEM, o envolvimento do cone medular e das raízes espinhais foi observado radiologicamente na ressonância magnética. Conclusão Os pacientes brasileiros com MOGAD apresentam um espectro clínico e radiológico semelhante aos fenótipos de MOGAD relatados anteriormente. O envolvimento do cone e das raízes espinhais parece estar frequentemente presente no MOGAD-ADEM e poderia servir como característica radiológica nesta entidade.

The present work aims to contribute to the study and development of methodologies for shrinkage tests of self-compacting concrete (SCC) using the addition of polypropylene (PP) microfibers as a variable to validate the correlations between the shrinkage tests. The objective of this work was to evaluate, through correlations between the area and the age at which the cracks appeared, the role of PP fibers as a control for this pathology. Reference SCC traces with additions of 6 mm and 12 mm microfibers were created for this purpose. For the shrinkage tests, the criteria of the ASTM C1579:2013 (plates) and ASTM C1581:2016 (rings) standards were used. The microfibers showed a significant reduction in cracks in the SCC, its reduction rate ranging from 40% to 70%, also presenting a delay in its appearance, which varied from 9 to 20 days for the appearance of the first crack.

ABSTRACT CBF measured with Arterial Spin Labeling (ASL) obtained by Magnetic Resonance Imaging (MRI) may become an important biomarker by showing changes in early stages of AD, such as in the prodromal stage of Mild Cognitive Impairment (MCI). Objective: Verify the correlation between atrophy and CBF in patients with MCI and mild phase ADD, to demonstrate whether changes in CBF can be considered as vascular biomarkers in the diagnosis of the DA continuum. Methods: 11 healthy volunteers, 16 MCI and 15 mild ADD were evaluated. Images of the brain were acquired, including CBF measured with Arterial Spin Labeling (ASL). Results: When comparing MCI with control, a reduction in normalized CBF was observed in left posterior cingulate (estimated difference -0.38; p=0.02), right posterior cingulate (estimated difference -0.45; p=0.02) and right precuneus (estimated difference -0.28; p <0.01); also increase in normalized CBF in right upper temporal pole (estimated difference 0.22; p=0.03). It was also observed that in MCI, the smaller the gray matter volume, the smaller the CBF in the left posterior cingulate; as well as the greater the cerebrospinal fluid volume, consequent to the encephalic volumetric reduction associated with atrophy, the greater the CBF in the right superior temporal pole. When comparing controls, MCI and mild AD, in relation to the other variables, no other correlations were observed between CBF and atrophy. Conclusion: In patients with MCI, the reduction of CBF in the left posterior cingulate correlated with gray matter atrophy, as well as the increase of CBF in the right upper temporal pole correlated with an increase in cerebrospinal fluid consequent to the encephalic volumetric reduction associated with atrophy, demonstrating the influence of CBF in AD related brain atrophy. These findings position CBF as a possible vascular biomarker for early-stage AD diagnoses.

RESUMO A imagem por ressonância magnética (IRM) pode se tornar um importante biomarcador ao mostrar alterações nos estágios iniciais da doença de Alzheimer (DA). Objetivo: Sendo a atrofia cerebral um importante biomarcador de neurodegeneração na DA, o presente estudo foi realizado com o objetivo de verificar se há correlação entre atrofia e fluxo sanguíneo cerebral (FSC) em pacientes com diagnóstico de CCL e demência da doença de Alzheimer (DDA) leve, com o objetivo de revelar se as alterações no FSC podem ser consideradas possíveis biomarcadores vasculares no diagnóstico do continuum da DA. Métodos: Foram avaliados 11 voluntários saudáveis, 16 CCL e 15 DDA leve. Imagens do cérebro foram adquiridas em um equipamento de 3 T, incluindo imagens ponderadas em T1 de alta resolução para avaliação anatômica e Arterial Spin Labeling (ASL) para a quantificação de FSC. Resultados: Quando comparado CCL com controle, observou-se redução no FSC normalizado em cingulado posterior esquerdo (diferença estimada de -0,38; p=0,02), cingulado posterior direito (diferença estimada de -0,45; p=0,02) e precúneo direito (diferença estimada de -0,28; p <0,01); e aumento de FSC normalizado no polo temporal superior direito (diferença estimada de 0,22; p=0,03). No CCL, quanto menor o volume da substância cinzenta, menor o FSC no cingulado posterior esquerdo; quanto maior o volume de fluido cerebroespinhal, consequente à redução volumétrica encefálica, maior o FSC no polo temporal superior direito. Conclusão: Nos pacientes com diagnóstico de CCL, a redução de FSC no cingulado posterior esquerdo apresentou correlação com atrofia da substância cinzenta, assim como o aumento de FSC no polo temporal superior direito apresentou correlação com o aumento de fluido cerebroespinhal, demonstrando a provável influência do FSC na atrofia encefálica relacionada à DA.

RESUMO Antecedentes: Meningiomas são os tumores mais frequentes do sistema nervoso central (SNC). Suas características étnicas e geográficas precisam ser conhecidas para o seu tratamento racional. Objetivo: Investigar aspectos clínicos e epidemiológicos de uma série de pacientes com meningiomas. Métodos: Análise retrospectiva demográfica de 993 pacientes com meningiomas (768 operados e 225 tratados conservadoramente) Resultados: Meningiomas constituíram 43.8% dos tumores primários do SNC. 0.8% deles eram múltiplos (14,7% com neurofibromatose 2) e 0,6% eram radioinduzidos. A idade média e o índice mulheres/homens foram respectivamente 53,0 e 63,9 anos e 3.2:1 e 6.3:1 para pacientes operados e não operados. O diagnóstico foi mais tardio em mulheres. Ocorreram picos de incidências na 6ª e na 7ª décadas respectivamente para pacientes operados e não operados. A incidência foi menor na infância e maior após 70 anos. Meningiomas predominaram no crânio (96.5%), a maioria grau I da OMS, subtipo transicional. Do total, 3.5% ocorreram no canal raquídeo, principalmente na região torácica, todos grau I, a maioria transicional. Em relação à distribuição racial, 1.0% dos meningiomas ocorreu em amarelos, 87% em brancos e 12% em negros. As taxas de sobrevida sem recorrência foram 83.4% e 51.6% em 10 e 20 anos e a mortalidade operatória foi 3%. Conclusões: A maioria dos dados demográficos observados foi similar aos de outros centros ocidentais. As diferenças observadas foram maior incidência, predominância em mulheres e idosos nos pacientes não operados e em caucasianos, e maior associação com neurofibromatose 2.

ABSTRACT Background: Meningiomas are the most frequent primary central nervous system (CNS) tumors. Their geographical and ethnic characteristics need to be known, in order to enable rational treatment. Objective: To investigate clinical and epidemiological aspects in a series of patients with meningiomas. Methods: Retrospective analysis on the demographic profile, location and histopathology of 993 patients with meningiomas (768 operated and 225 not operated). Results: Meningiomas represented 43.8% of the primary CNS tumors; 6.8% were multiple tumors (14.7% with neurofibromatosis 2) and 0.6% were radiation-induced tumors. The mean ages were 53.0 and 63.9 years for operated and non-operated patients and the female/male ratios were 3.2:1 and 6.3:1. Diagnosis was made later among females. The peak incidences were in the 6th and 7th decades respectively for operated and non-operated patients. The incidence was low at early ages and higher among patients aged 70+ years. The meningiomas were intracranial in 96.5% and most were WHO grade I (88.9%) and transitional. In the spinal canal (3.5%), they occurred mainly in the dorsal region (all grade I; mostly transitional). The racial distribution was 1.0% in Asian-Brazilians, 87% in Caucasians and 12% in African-Brazilians. 83.4% and 51.6% of the patients were estimated to be recurrence-free at 10 and 20 years, and the mortality rate was 3%. Conclusions: Most of the demographic data were similar to what has been observed in other western centers. Differences were higher incidence of meningiomas, female and older predominance in non-operated patients, predominance in Caucasian, and higher association with neurofibromatosis 2.

Resumo Este trabalho apresenta um estudo sobre o efeito de escala na metodologia para análise do fenômeno do colapso de interface entre concreto e polímero reforçado com fibra (PRF) de carbono por meio de corpos de prova cilíndricos. Buscou-se analisar a influência da variação da dimensão do corpo de prova ao manter a mesma geometria de PRF aderida. Para a análise do efeito de escala, foram realizados experimentos de tração direta com três dimensões de corpos de prova cilíndricos (diâmetro × altura): 50 mm × 100 mm, 100 mm × 200 mm, e 150 mm × 300 mm. Dez geometrias diferentes do material compósito foram testadas. Dois modos de falha foram observados nos experimentos: deslizamento entre os dois materiais e falha por tração no concreto. Nos experimentos com falha na interface, não se notou uma influência da dimensão do corpo de prova na força máxima, tensão de cisalhamento até o pico, e rigidez no descolamento entre concreto e PRF. No entanto, o uso de corpos de prova menores é limitado, pois muitas vezes é atingida a tensão normal limite que o concreto resiste, causando sua ruptura.

Abstract This is a study about the size effect on the methodology with concrete cylinder specimens for analysis of the debonding phenomenon at the interface between concrete and carbon fiber reinforced polymer (FRP). The influence of the concrete specimen size variation is analyzed by maintaining the same geometry in adhered FRP. Direct tensile experiments were performed with three dimensions of cylindrical concrete specimens (diameter × height) for analysis of size effect: 50 mm × 100 mm, 100 mm × 200 mm, and 150 mm × 300 mm. Ten different geometries of the composite material were tested. Two failure modes were observed in the experiments: debonding between the two materials and tensile failure in concrete specimens. In experiments with interface failure, the size of concrete specimens has no significant influence on maximum force, shear stress to peak, and stiffness in debonding between concrete and FRP. However, the use of smaller specimens for analysis of interface collapse is limited because the concrete reaches its normal stress capacity with a lower tensile force, and therefore, the failure often occurs in the concrete.

Resumo Os modelos disponíveis para o ensino de ondas, principalmente no ensino médio, não levam em consideração o estágio de desenvolvimento real em que se encontra a grande maioria dos estudantes [1]. Aliado a isso, a dificuldade em se apresentar frequências, sejam de natureza eletromagnética ou mecânica (sonora), diferentes das faixas que somos capazes de interpretar através dos nossos sentidos, tende a constituir um enorme obstáculo epistemológico. Numa tentativa de lançar alguma luz sobre esse problema, desenvolvemos dois experimentos que apresentam relações entre frequências invisíveis e inaudíveis, mas que, através do processamento com a plataforma Arduino, podem ser convertidas em frequências que sensibilizem nossos sentidos. Desta forma pretende-se descortinar esse mundo invisível, trazendo para a sala de aula experimentos que podem ser utilizados, inclusive, por estudantes com deficiência visual ou auditiva.

Abstract The models available for teaching waves, especially in high school, do not consider the stage of real development in which the vast majority of students are [1]. Allied to this, the difficulty in presenting frequencies, either of electromagnetic or sonorous nature, different from the bands that we can interpret through our senses, tends to constitute a huge epistemological obstacle. In an attempt to shed some light on this problem, we have developed two experiments that have relations between invisible and inaudible frequencies but which, through processing with Arduino platform, can be converted into audible frequencies. Thus, we intend to unveil this invisible world, bringing to the classroom experiments that can be used, even by students with blindness or deafness.

Abstract Introduction Multiple Sclerosis (MS) is a neurodegenerative disease characterized by inflammatory demyelination in the central nervous system. Quantitative Magnetic Resonance Imaging (qMRI) enables a detailed characterization of brain tissue, but generates a large number of numerical results. In this study, we elucidated the main qMRI techniques and the brain regions that allow the identification of MS patients from neuroimaging data and pattern recognition techniques. Methods The data came from the combination of computational tools of image processing and neuroimaging acquired in a 3 Tesla scanner using different techniques: Diffusion, T2 Relaxometry, Magnetization Transfer Ratio (MTR) and Structural Morphometry. Data from 126 brain regions of 203 healthy individuals and 124 MS patients were separated into two groups and processed in a data-mining program using the k-nearest-neighbor (KNN) algorithm. Results The most relevant anatomical structures in the classification procedure were: corpus callosum, precuneus, left cerebellum and fusiform. Among the quantitative techniques the most relevant was the MTR, being indicated for longitudinal studies of this disease. KNN with 5 neighbors and pre-selected attributes had a better performance with an area under the ROC curve (97.3%) and accuracy (95.7%). A restricted classification considering only brain regions previously reported in the literature as affected by MS brought slightly lower scores, area: 97.1% and accuracy: 93.2%. Conclusion The use of standard recognition techniques from quantitative neuroimaging techniques has confirmed that the white matter of the brain is the most affected tissue by MS following a global pattern with greater involvement of the left hemisphere.

Resumo Objetivo: Examinar o potencial das imagens de contraste dinâmico (DCE-MRI) e difusão (DW-MRI) em ressonância magnética na detecção de linfonodos cervicais malignos. Materiais e Métodos: Foram realizadas DCE-MRI e DW-MRI em 33 linfonodos cervicais. Os valores de realce relativo máximo, realce relativo, tempo de pico, taxa de realce e lavagem, brevidade do realce e área sob a curva foram avaliados pela análise semiquantitativa (DCE-MRI). Os coeficientes de difusão aparente na DW-MRI foram obtidos na área de interesse. Foram excluídas partes císticas ou necróticas dos nódulos. Todos os pacientes foram submetidos a dissecção cervical ou a biópsia. Os resultados de imagem foram correlacionados com os achados patológicos. Nenhum paciente foi submetido a tratamento neoadjuvante antes da dissecção do pescoço. Resultados: Realce relativo, realce relativo máximo e taxa de realce aumentaram nos nódulos malignos (p < 0,009, p < 0,05 e p < 0,03, respectivamente). O tempo de pico foi reduzido nos nódulos malignos (p < 0,02). A análise multivariada identificou tempo de pico (sensibilidade, 73,7%; especificidade, 69,2%) e realce relativo (sensibilidade, 89,2%; especificidade, 69,2%) como variáveis capazes de distinguir os nódulos benignos e malignos. Conclusão: Embora o DCE-MRI possa diferenciar os nódulos benignos e malignos, ainda não há consenso sobre a técnica de análise semiquantitativa, em razão de dificuldade de aplicação clínica. Valores baixos do coeficiente de difusão aparente podem predizer nódulo metastático, mas devem-se considerar também resultados falso-positivos, provavelmente secundários ao processo inflamatório.

Abstract Objective: To examine the potential of two magnetic resonance imaging (MRI) techniques-dynamic contrast enhancement (DCE) and diffusion-weighted imaging (DWI)-for the detection of malignant cervical lymph nodes. Materials and Methods: Using DCE and DWI, we evaluated 33 cervical lymph nodes. For the DCE technique, the maximum relative enhancement, relative enhancement, time to peak enhancement, wash-in rate, wash-out rate, brevity of enhancement, and area under the curve were calculated from a semi-quantitative analysis. For the DWI technique, apparent diffusion coefficients (ADCs) were acquired in the region of interest of each lymph node. Cystic or necrotic parts were excluded. All patients underwent neck dissection or node biopsy. Imaging results were correlated with the histopathological findings. None of the patients underwent neoadjuvant treatment before neck dissection. Results: Relative enhancement, maximum relative enhancement, and the wash-in rate were significantly higher in malignant lymph nodes than in benign lymph nodes (p < 0.009; p < 0.05; and p < 0.03, respectively). The time to peak enhancement was significantly shorter in the malignant lymph nodes (p < 0.02). In the multivariate analysis, the variables identified as being the most capable of distinguishing between benign and malignant lymph nodes were time to peak enhancement (sensitivity, 73.7%; specificity, 69.2%) and relative enhancement (sensitivity, 89.2%; specificity, 69.2%). Conclusion: Although DCE was able to differentiate between benign and malignant lymph nodes, there is still no consensus regarding the use of a semi-quantitative analysis, which is difficult to apply in a clinical setting. Low ADCs can predict metastatic disease, although inflammatory processes might lead to false-positive results.

Resumo: O ambiente competitivo do agronegócio tem pressionado os atores organizacionais das cooperativas lácteas para implementar novas estruturações. Nesse sentido, diversos pesquisadores têm percebido a existência de práticas isomórficas que não são adequadas para empreendimentos cooperativos. Este artigo teórico assume que existem ações estratégicas relacionadas as demandas institucionais implementadas pelos tomadores de decisão em relação às pressões ambientais. Assim, almejou-se analisar como podem ser estruturadas tais ações estratégicas em relação às pressões institucionais de dois subcampos organizacionais relacionados ao cooperativo de forma a manutenção da legitimidade do negócio. Foram traçadas a projeção de cinco quadros analíticos. Como conclusão, é inferido que nem sempre a reestruturação do negócio cooperativo tenderá a expressar um atomismo dos tomadores de decisão em relação às demandas institucionais do campo organizacional. Isso ocorreria uma vez que tais demandas são ambivalentes e precisam ser coordenadas conjuntamente na ordem para obterem um nível mínimo de legitimidade, que é necessária para a sobrevivência organizacional.

Abstract: The competitive agribusiness environment has been pressing organizational actors of dairy cooperatives to implement new structures. In this sense, many scholars advocate the existence of isomorphic practices that are not suitable for cooperative enterprises. This theoretical paper assumes that there are strategic actions related to the institutional demands, implemented by cooperative decision makers in relation to environmental pressures. Thus, we aimed to analyze how can be structured such strategic actions in relation to the institutional pressures of two organizational subfields related to cooperative business, in order to maintain the legitimacy of the business. For this, we drafted the projection of five analytical frameworks. As conclusions, it is inferred that a cooperative business restructuring not always tends to express an atomism of decision makers in relation to institutional demands of the organizational field, given that the demands are ambivalent and need to be met in order to obtain minimum level of legitimacy necessary for the organization survival.

Resumo Disseminação perineural de tumores refere-se à extensão de células tumorais ao longo do tecido dos nervos. Acarreta um pior prognóstico, aumenta a taxa de recorrência e diminui a expectativa de vida em cinco anos em até 30%. É um achado importante em exames de imagem quando se estadia pacientes com cânceres de cabeça e pescoço, já que não pode ser avaliado somente pelo cirurgião. Todavia, é uma alteração que frequentemente passa despercebida. No presente estudo, revisamos trabalhos científicos da literatura médica sobre os achados de imagem e os aspectos fisiopatológicos desse tipo de disseminação e analisamos 10 exames de imagem com sinais radiológicos de disseminação perineural oriundos de um hospital-escola brasileiro.

Abstract Perineural tumor spread refers to the migration of tumor cells along nerve tissues. It worsens the prognosis, increases the recurrence rate, and diminishes 5-year survival by up to 30%. It is an important finding on imaging tests employed in the staging of patients with head and neck cancers, because it cannot be assessed by the surgeon alone. Nevertheless, it is frequently overlooked. In this study, we reviewed the literature regarding the imaging and pathophysiological aspects of this type of dissemination. We also analyzed ten imaging tests, obtained from a teaching hospital in Brazil, in which there were radiological signs of perineural tumor spread.

Abstract Introduction: Diffusion tensor imaging (DTI) is an important medical imaging modality that has been useful to the study of microstructural changes in neurological diseases. However, the image noise level is a major practical limitation, in which one simple solution could be the average signal from a sequential acquisition. Nevertheless, this approach is time-consuming and is not often applied in the clinical routine. In this study, we aim to evaluate the anisotropic anomalous diffusion (AAD) filter in order to improve the general image quality of DTI. Methods A group of 20 healthy subjects with DTI data acquired (3T MR scanner) with different numbers of averages (N=1,2,4,6,8, and 16), where they were submitted to 2-D AAD and conventional anisotropic diffusion filters. The Relative Mean Error (RME), Structural Similarity Index (SSIM), Coefficient of Variation (CV) and tractography reconstruction were evaluated on Fractional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) maps. Results The results point to an improvement of up to 30% of CV, RME, and SSIM for the AAD filter, while up to 14% was found for the conventional AD filter (p<0.05). The tractography revealed a better estimative in fiber counting, where the AAD filter resulted in less FA variability. Furthermore, the AAD filter showed a quality improvement similar to a higher average approach, i.e. achieving an image quality equivalent to what was seen in two additional acquisitions. Conclusions In general, the AAD filter showed robustness in noise attenuation and global image quality improvement even in DTI images with high noise level.

Abstract Introduction The interpretation of brain tumors and abscesses MR spectra is complex and subjective. In clinical practice, different experimental conditions such as field strength or echo time (TE) reveal different metabolite information. Our study aims to show in which scenarios magnetic resonance spectroscopy can differentiate among brain tumors, normal tissue and abscesses using classification algorithms. Methods Pairwise classification between abscesses, brain tumor classes, and healthy subjects tissue spectra was performed, also the multiclass classification between meningiomas, grade I-II-III gliomas, and glioblastomas and metastases, in 1.5T short TE (n = 195), 1.5T long TE (n = 231) and 3.0T long TE (n = 59) point resolved spectroscopy setups, using LCModel metabolite concentration as input to classifiers. Results Areas under the curve of the Receiver Operating Characteristic above 0.9 were obtained for the classification between abscesses and all classes except glioblastomas, reaching 0.947 when classifying against metastases, grade I-II gliomas and glioblastomas (0.980), meningiomas and glioblastomas (0.956), grade I-II gliomas and metastases (0.989), meningiomas and metastases (0.990), and between healthy tissue and all other classes in both conditions except for anaplastic astrocytomas in short TE 1.5T setup. When the multiclass classification agrees with radiological diagnosis the accuracy reaches 96.8% for short TE and 98.9% for long TE. Conclusions The results in the three conditions were similar, highlighting comparable quality, robust quantification and good regularization and flexibility in either algorithm. Multiclass classification provides useful information to the radiologist. These findings show the potential of the development of decision support systems as well as tools for the accompaniment of treatments.

Resumo O módulo de elasticidade do concreto é uma propriedade importante para os profissionais envolvidos na indústria da construção civil, uma vez que seu valor é determinante para o controle das deformações. Este trabalho avaliou o módulo de elasticidade de três classes distintas de concreto (C20, C30 e C40) produzidas com dois tipos litológicos de rochas, basalto e dolomito, de diferentes jazidas da região do Triângulo Mineiro. Como parte do estudo experimental, foram moldadas 324 amostras cilíndricas de 10 cm × 20 cm. Os valores de módulo de elasticidade obtidos foram comparados com seis formulações propostas em quatro normas, institutos e códigos do concreto: ABNT NBR 6118 versão 2007 e 2014, ACI 318, EUROCODE 2 and FIB Model Code, Ibracon 2003. Dentre as formulações propostas pelas normas, as indicadas pela FIB Model Code (2010) e ABNT NBR 6118 (2014) apresentaram valores mais próximos aos resultados experimentais deste estudo.

Abstract The elastic modulus is an important property for professionals in the construction industry, since its value is crucial for deformation control. This study evaluates the elastic modulus of three different classes of concrete (C20, C30 and C40), produced with two lithologic types of rocks, basalt and dolomite, from the Triângulo Mineiro region, Brazil. In the experimental study, 324 cylindrical test specimens were cast. The experimental results of the elastic modulus were compared to six formulations proposed in four concrete norms and codes: ABNT NBR 6118, version 2007 and 2014, ACI 318, EUROCODE 2, FIB Model Code and IBRACON (2003). The elastic modulus values obtained with the formulation proposed by FIB Model Code (2010) and ABNT NBR 6118 (2014) were closest to the experimental results of this study.

RESUMO A fim de verificar os aspectos da indicação cirúrgica, vinte e sete pacientes com epilepsia refratária secundária a tumor cerebral, com idade de até 19 anos na cirurgia, operados entre 1996 e 2013 e seguidos por pelo menos um ano, foram estudados. O intervalo médio entre o início das crises e o diagnóstico do tumor foi de 3,6 anos, e deste para a cirurgia, 18 meses. A localização do tumor foi lobo temporal em 16, sendo ganglioglioma e DNET os tipos mais frequentes. Entre os pacientes, 92,5% e 90,4% estavam livres de crises no primeiro e no quinto ano após a cirurgia, respectivamente. Doze de 16 crianças obtiveram sucesso na retirada de drogas, com a média de tempo de 3,2 anos após o procedimento. A cirurgia provou ser potencialmente curativa e segura nestes casos, o que sugere que perante o diagnóstico de tumor esta não pode ser adiada.

ABSTRACT In order to verify indications for surgery, 27 patients with refractory epileptic seizures and brain tumor, aged up to 19 years at the time of surgery, were studied between 1996 and 2013 and followed up for at least one year. The mean interval between the onset of seizures and the diagnosis of the tumor was 3.6 years, and from diagnosis to the surgery, 18 months. The location of the tumor was in the temporal lobe in 16, with ganglioglioma and dysembryoplastic neuroepithelial tumors being the most frequent. Among the patients, 92.5% and 90.4% were seizure-free in the first and fifth year after surgery, respectively. Twelve of 16 children were successful in becoming drug-free, with complete withdrawal by 3.2 years. Surgery proved to be potentially curative and safe in these cases, suggesting that the tumor diagnosis and surgery cannot be postponed.