284 research outputs found
Morfometria do trato vocal por ressonância magnética: simulação de padrões patológicos articulatórios
Introdução - A análise da forma ou morfometria de estruturas anatómicas, como o trato vocal, pode ser efetuada a partir de imagens bidimensionais (2D) como de aquisições volumétricas (3D) de ressonância magnética (RM). Esta técnica de imagem tem vindo a ter uma utilização crescente no estudo da produção da fala. Objetivos - Demonstrar como pode ser efetuada a morfometria do trato vocal a partir da imagem por ressonância magnética e ainda apresentar padrões anatómicos normais durante a produção das vogais [i a u] e dois padrões articulatórios patológicos em contexto simulado. Métodos - As imagens consideradas foram recolhidas a partir de aquisições 2D (Turbo Spin-eco) e 3D (Flash Gradiente-Eco) de RM em quatro sujeitos durante a produção das vogais em estudo; adicionalmente procedeu-se à avaliação de duas perturbações articulatórias usando o mesmo protocolo de RM. A morfometria do trato vocal foi extraÃda com recurso a técnicas manuais (para extração de cinco medidas articulatórias) e automáticas (para determinação de volumes) de processamento e análise de imagem. Resultados - Foi possÃvel analisar todo o trato vocal, incluindo a posição e a forma dos articuladores, tendo por base cinco medidas descritivas do posicionamento destes órgãos durante a produção das vogais. A determinação destas medições permitiu identificar quais as estratégias mais comummente adotadas na produção de cada som, nomeadamente a postura articulatória e a variação de cada medida para cada um dos sujeitos em estudo. No contexto de voz falada intersujeitos, foi notória a variabilidade nos volumes estimados do trato vocal para cada som e, em especial, o aumento do volume do trato vocal na perturbação articulatória de sigmatismo. Conclusão - A imagem por RM é, sem dúvida, uma técnica promissora no estudo da fala, inócua, não-invasiva e que fornece informação fiável da morfometria do trato vocal.Introduction - The shape or morphologic analysis of anatomical structures, such as the vocal tract can be performed from two-dimensional (2D) or volumetric acquisitions (3D) of magnetic resonance imaging (MRI). This imaging technique has had an increasing use in the study of speech production. Objectives - To determine a method to perform the morphometric analysis of the vocal tract from magnetic resonance imaging; to present anatomical patterns during the normal speech production of some vowels and two pathological articulatory disorders in simulated context. Methods - The image data was collected from 2D (Turbo Spin Echo) and 3D (Flash Gradient Echo) acquisitions of MRI of four subjects during the production of three vowels; in addition, two articulatory disorders were assessed using this imaging protocol. The morphology of the vocal tract was extracted using manual and automatic techniques of image processing and analysis. Results - Based on five articulatory measurements, it was possible to study the entire vocal tract during vowel production, including the position and shape of the articulators involved. Based on these measurements, it was possible to identify the strategies most commonly adopted in the production of each sound, including the articulatory posture and the modification of each measure for the subjects under study. Concerning the voices of the different speakers, the variability in the assessed volumes of the vocal tract for each sound was found, and in particular, the increased vocal tract volume in the articulatory disorder - the sigmatism. Conclusion - MRI is a promising technique for speech production studies, safe, non-invasive and that provides reliable information concerning the morphometric analysis of the vocal tract
Utilização da Imagem por Ressonância Magnética nos Estudos sobre a Produção da Fala
A fala é uma ferramenta única de comunicação, que envolve um conjunto de órgãos que trabalham sincronamente na produção de sons. Os mecanismos envolvidos são complexos, sendo várias as técnicas de estudo da fala, quer do ponto de vista acústico, quer do ponto de vista morfológico. A ressonância magnética tem revelado potencialidades únicas no estudo do tracto vocal, e que são aqui destacadas. O principal objectivo deste estudo é dar a conhecer esta técnica de imagem e demonstrar a sua utilização no estudo da produção da fala, nomeadamente do Português Europeu. Através da recolha e análise de imagens foi possÃvel a obtenção e construção de modelos tridimensionais do tracto vocal nas mais variadas posições articulatórias. Recorrendo a uma técnica de sincronização através de monitorização cardÃaca e a aquisições de imagem ultra-rápidas foi possÃvel também a captação dinâmica por sub-amostragem e a observação dos movimentos articulatórios envolvidos durante a produção de três sÃlabas. A caracterização morfológica e dinâmica do tracto vocal com base nas imagens de ressonância magnética é, face aos resultados obtidos, fiável e deveras importante para o conhecimento deste mecanismo. Para além disso, a informação obtida desperta um interesse multidisciplinar e aplicações diversas com potencialidades marcantes face aos esperados avanços tecnológicos desta técnica de imagem
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This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativeco mmons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/ zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the dat
Fractura Coronal do Capitellum e Tróclea Umeral em Idade Pediátrica
As fracturas coronais do úmero distal podem envolver o capitellum, tróclea umeral ou ambos. São fracturas raras na idade adulta e ainda mais raras em idade pediátrica.
Apresentamos um caso de uma adolescente de 13 anos que se apresenta com uma fractura coronal do capitellum e tróclea umeral. Foi classificada como tipo IV de McKee. Realizou-se uma redução aberta e osteossÃntese com 2 parafusos interfragmentários postero-anteriores. Aos 3 meses pós-operatórios a fractura estava consolidada e a doente apresentava-se sem queixas e com boa mobilidade do cotovelo.
Há a salientar a necessidade de caracterizar bem estas fracturas e ter em atenção à existência de lesões associadas.
A redução anatómica associada a uma osteossÃntese estável, permitindo uma mobilização precoce permitem obter os melhores resultados.info:eu-repo/semantics/publishedVersio
Importância prognóstica do alelo CYP2C19*2 após uma sÃndrome coronária aguda: dados de um centro nacional
BACKGROUND: Clopidogrel requires oxidation dependent on the cytochrome P450 enzyme 2C19 (CYP2C19) to form its active metabolite. The importance of loss-of-function alleles (particularly CYP2C19*2, 681G>A) in poor platelet response to clopidogrel is well recognized.
OBJECTIVE: To investigate the prevalence and prognostic impact of the CYP2C19*2 allele in a local acute coronary syndrome (ACS) population.
METHODS: We performed a prospective, longitudinal study of 95 patients admitted for an ACS between March and October 2009 to a single coronary care unit. Patients aged under 75 who survived hospital stay and for whom clopidogrel was prescribed were included. At discharge, CYP2C19 was genotyped using a commercially available kit. Patients were divided into two groups: Group A (non-carriers, normal metabolizers, CYP2C19*1/*1), n=69; and Group B (carriers, slow metabolizers, CYP2C19*2/*1 or *2/*2), n=26. The primary endpoint was a combined outcome of cardiovascular death, non-fatal myocardial infarction or re-admission for unstable angina; median follow-up was 136.0 (79.0-188.0) days.
RESULTS: The median age of the population was 62.0 (51.0-68.0) years, and 83.2% were male. The CYP2C19*2 (A) allele had a frequency of 14.2%. There were no differences between the groups with respect to demographic data or history of cardiovascular disease. Coronary anatomy, left ventricular ejection fraction and renal function were also similar. The groups were also homogenous with respect to GRACE risk score (118.0 (95.0-136.5) vs. 115.0 (96.0-133.0), p=0.68), medical treatment and percutaneous revascularization during hospital stay. Event-free survival was higher for Group A (94.0% vs. 75.0%, log-rank p=0.010). Three readmissions for MI were documented, all in the slow metabolizers group.
CONCLUSION: In our ACS population, the CYP2C19*2 allele was a medium-term prognostic marker
Development of photocatalytic 3D-Printed cementitious mortars: influence of the curing, spraying time gaps and TiO2 coating rates
This work evaluated the photocatalytic activity of 3D-printed cementitious mortar specimens functionalized with TiO2 nanoparticles to obtain a multifunctional and smart concrete. This research aims to assess the influence of different parameters related to the functionalization process such as adsorption, coating time gaps, and coating rates on the degradation efficiency of the functionalized cementitious specimens. Each specimen was evaluated under the degradation of Rhodamine B (RhB) in an aqueous solution using a sun-light simulation. The obtained results showed a decrease in adsorption (under dark condition) with increasing the sample curing age. The highest photocatalytic efficiency was observed for coated samples aged 7 days. By increasing the coating rates, the photocatalytic efficiency is enhanced. Nonetheless, regardless of the coating rates, all the specimens showed an increase in photocatalytic efficiency for longer time periods of light exposition, i.e., after 8 h of irradiationThis work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE),
under reference UIDB/04029/2020. The authors acknowledge the support of the DST group
construction company for funding the project Chair dst/IB-S: Smart Systems for Construction.
The first two authors would like to acknowledge the PhD grants SFRH/BD/143636/2019 and
SFRH/BD/137421/2018 provided by the Portuguese Foundation for Science and Technology (FCT).
Additionally, the authors would like to acknowledge FCT for the financing this research work by the
project NanoAir PTDC/FIS-MAC/6606/2020 and the Strategic Fundings UIDB/04650/2020-2023
and UIDB/04029/202
3D vocal tract reconstruction using magnetic resonance imaging data to study fricative consonant production
The development of Magnetic Resonance Imaging (MRI) has grown rapidly in clinical practice. Currently, the use of MRI in speech research provides useful and accurate qualitative and quantitative data of speech articulation. The aim of this work was to describe an effective method to extract vocal tract and compute their volumes during speech production from MRI images. Using a 3.0 Tesla MRI system, 2D and 3D images of the vocal tract were collected and used to analyze the vocal tract during the production of fricative consonants. These images were also used to build the associated 3D models and compute their volumes. This approach showed that, in general, the volumes measured for the voiceless consonants are smaller than the counterpart voiced consonants. (c) Springer International Publishing Switzerland 2015
Green lacewings (Neuroptera: Chrysopidae) associated with Melon Crop in Mossoró, Rio Grande do Norte State, Brazil
Sustainability impact assessment of land use changes in Mercosur countries: SIAT Mercosur development.
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