Estudo da dose efetiva, razão sinal-ruído e razão contraste-ruído em tomografia computadorizada de múltiplos detetores

Since discovery, computed tomography is a widely used diagnostic modality. However, this modality imparts relatively high doses to the patients and with fast technological advancement, it is necessary optimize the doses used and ensure the quality of the images through a quality assurance program. This work intended to compare Computed Tomography Dose Index (CTDIW) and effective dose with components of image quality: the Contrast-to-Noise Ratio (CNR) and Signal-to-Noise Ratio (SNR), and a quality factor (Q) deduced by the Rose model for two groups of computed tomography units. The first group was composed by equipments with 10 up to 16 slices and the second one presented 40 up to 320 slices detectors, for the protocols of head and abdomen. It was realized a comparison between different selectable parameters in the protocol of a Philips Brilliance 16, too. The results of the first group to CTDIW, effective dose, SNR and CNR showed variations of 28%, 33%, 37% and 32% respectively for head protocol, and 21%, 27%, 43% and 37% respectively for abdomen protocol. The results of the group 2 to CTDIW, effective dose, SNR and CNR showed variations of 15%, 26%, 36% and 34% respectively for the head protocol, and 8%, 13%, 50% and 60% respectively for abdomen protocol. The comparison between both groups demonstrated similar levels of doses impartation to patients though having so many different configurations, if the uncertainties associated with this measurement were considered. The results of the comparison between different parameters in the Philips Brilliance 16 scanner were in agreement with expected

Síntese e caracterização de ferritas de manganês e zinco visando aplicação como agente de contraste em diagnóstico médico

This work aims to synthesize the manganese and zinc ferrite, by the polymeric precursor method, in order to obtain materials with appropriate characteristics for the application in medical diagnosis techniques. The manganese and zinc ferrite powders with the composition of Mn(1-x)ZnxFe2O4, where x=0,23, were prepared and calcined in air at different times and temperatures. The X-ray diffraction (XRD) data show that the sample calcined at 400°C crystallize as ferrite (monophase), but in an inverted spinel structure (high content of iron occupying manganese tetrahedral site and manganese occupying the iron octahedral site). The samples calcined at temperatures between 600°C and 900°C shows the secondary phase of hematite and the sample calcined at 1100oC shows to be monophase in ferrite with normal spinel structure. The monophase powders of ferrite showed a reduction in the surface area and an increasing in the pore size for higher calcination temperatures. The magnetic analysis show that the sample calcined at 400°C presents satisfactory magnetization at room temperature, however, it behaves as diamagnetic material at low temperatures (10K). The powder containing hematite, without the partial substitution of iron ions by manganese, showed to have low transition temperature, and consequently low magnetization at room temperature. The hematite, when partially substituted, provides materials with irregular magnetization at the saturation region. The powder calcined at 1100°C shows high magnetization either at room temperature or low temperature (10K)

Clivagem e construções similares: contraste, foco e ênfase

This paper deals with so called cleft constructions and other similar structures in eight Portuguese varieties, aiming to show that the formal differences correspond to different functional strategies used by the Speaker to achieve his/her communicative intentions, i.e., Focus, Contrast and Emphasis, in accordance with the theory of Functional Discourse Grammar (Hengeveld and Mackenzie, 2008). This study takes as evidence real spoken occurrences extracted from a corpus organized by Linguistic Centre at the University of Lisbon, in partnership with the University of Toulousse Mirail and the University of Provence-Aix-Marseille. The results show the following distribution: cleft construction is a strategy for pragmatic function Contrast marking; Focus-ser constructions are used to highlight a constituent and (é) que is used as an operator of emphasis showing the speaker’s desire to intensify certain pieces of information.

Estabelecimento do contraste entre as fricativas por crianças com transtorno fonológico: manipulação de pistas acústicas

The present study focuses on the presence of covert contrasts in the speech of children with a phonological disorder. The hypothesis is that children with phonological disorders manipulate secondary acoustic cues in an attempt to distinguish the phonological contrasts. We used five audio recordings of the speech of five children with speech disorders, between four and five years of age, who showed the so-called “phonic substitution” involving the sound group of the fricatives. The data were edited and analyzed using the software PRAAT. A phonetic transcription of the first repetition of each child was performed by three evaluators, reaching a 66% agreement level. After the transcription, we carried out a contrastive phonological analysis of the production of the five children and, finally, an acoustic analysis of all the “substitutions”, based on six parameters. We discovered the existence of covert contrasts in the productions auditorily regarded as homophones by the evaluators, representing a total of 54% of total substitutions identified through an impressionistic approach by the evaluators. Children with phonological disorders are seen to rely on secondary acoustic cues in an attempt to distinguish fricative phonemes. The data obtained in this study allow us to reflect on the importance of considering the phonetic detail within the phonological models.

Estudo mielográfico comparativo entre meios de contraste iopamidol e ioexol em bezerros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ultrassonografia modo B de alta resolução modo Doppler e uso de contraste de microbolhas na avaliação testicular de gatos domésticos

Pós-graduação em Medicina Veterinária - FCAV

Bulas de medicamentos alemãs e brasileiras em contraste: alguns resultados da análise linguística

Na presente pesquisa foi desenvolvido um estudo linguístico contrastivo de textos de bulas de medicamentos da Alemanha e do Brasil com o objetivo de verificar a existência de diferenças e semelhanças entre eles. Para isso, um total de 20 bulas foram comparadas em seus níveis macro e microestrutural, após uma investigação detalhada das principais características do gênero em questão. Ao final da análise contrastiva, foi confirmada a presença de convergências e divergências no gênero, tendo em vista o par linguístico adotado, e também identificadas algumas explicações para tal.

Estudio y desarrollo de nuevas metodologías analíticas basadas en la utilización de medios micelares para la extracción y determinación de derivados fenólicos en muestras de interés medioambiental

Premio Extraordinario de Doctorado ; Premio a la Mejor Tesis Doctoral por el Área de Experimentales Premio de Investigación Viera y Clavijo (Ciencias Químicas, Física y Exactas) 2007

El sistema ABC en contraste con las nuevas tendencias en contabilidad

[ES] Dada la importancia creciente del cálculo de los costes en las empresas se efectúa un estudio comparativo de las tendencias actuales en los sistemas de información de los costes.