5,116 research outputs found
Quantitative gated blood pool tomographic assessment of regional ejection fraction: Definition of normal limits
AbstractObjective. Our aim was to select a method of analysis for gated blood pool tomography that reduced variability in a group of normal subjects, allowed comparison with normal limit files and displayed results in the bull's-eye format.Background. Abnormalities in left ventricular function may not be accurately detected by measures of global function because hyperkuiesia in normal regions may compensate for abnormal regional function. Gated blood pool tomography acquires threedimensional data and offers advantages over other noninvasive modalities Tor quantitative assessment of global and regional function.Methods. Alternative methods for selecting the ventricular axis, calculating regional ejection fraction and choosing the number of ventricular divisions were studied In 15 normal volunteers to select the combination of parameter that produced the lowest variability in quantitative regional ejection fraction. Methods for quantitative comparison, of regional ejection fraction with normal limit files and for display in the bull's-eye format were also examined.Results. A fixed axis (the geometric center of the ventricle defined for end-diastole and used for end-systole) gave ejection fractions that were significantly higher in the lateral wall versus in the septum, 82 ± 8 (mean ± 1 SD) versus 39 ± 17 (p < 0.001) at the midcavity and 66 ± 11 versus 21 ± 20 (p < 0.001) at the base. A floating axis system (axis defined individually for end-diastole and end-systole and realigned at the center) gave more uniform regional ejection fraction: 63 ±6 versus 64 ± 8 (p = NS) at the midcavity and 44 ± 16 versus 45 ± 15 (p = NS) at the base. The coefficient of variability for regional ejection fraction was consistently lower using a floating axis. Calculating regional ejection fraction by dividing the regional stroke volume by the enddiastollc volume of the region gave a lower coefficient of variability and a more easily understood value than dividing the regional stroke volume by the total end-diastolic volume of the ventricle. Although the variability was lower using five versus nine ventricular divisions, nine regions offer greater spatial resolution. Comparison of regional ejection fraction with normal data identified regions > 2.5 SD below the mean as abnormal. We described the two-dimensional bull's-eye format as a method for displaying the regional three-dimensional data and illustrated abnormalities in patients with prior myocardial infarction.Conclusions. Gated blood pool tomography performed using a floating axis system, regional stroke volume calculation of ejection fraction and nine regions uses all the three-dimensional blood pool data to calculate regional ejection fraction, allow quantitative comparison with normal limit tiles, display the functional data in the two-dimensional bull's-eye format and demonstrate abnormalities in patients with myocardial infarction
Repeated assessment and practice effects of the written symbol digit modalities test using a short inter-test interval
The Symbol Digit Modalities Test (SDMT) is a widely used instrument to assess information processing speed, attention, visual scanning, and tracking. Considering that repeated evaluations are a common need in neuropsychological assessment routines, we explored test–retest reliability and practice effects of two alternate SDMT forms with a short inter-assessment interval. A total of 123 university students completed the written SDMT version in two different time points separated by a 150-min interval. Half of the participants accomplished the same form in both occasions, while the other half filled different forms. Overall, reasonable test–retest reliabilities were found (r = .70), and the subjects that completed the same form revealed significant practice effects (p < .001, dz = 1.61), which were almost non-existent in those filling different forms. These forms were found to be moderately reliable and to elicit a similar performance across participants, suggesting their utility in repeated cognitive assessments when brief inter-assessment intervals are required.This work was supported by European Union FEDER funds through Programa Operacional Factores de Competitividade (COMPETE) for ADI Project "DoIT-Desenvolvimento e Operacionalizacao da Investigacao de Translacao" ("MyHealth-PPS4"; project no 13853)
Nanoemulsions for food applications: development and characterization
The application of nanotechnology to food, medical and pharmaceutical industries has received great attention from the scientific community. Driven by the increasing consumers’ demand for healthier and safer food products and the need for edible systems able to encapsulate, protect, and release functional compounds, researchers are currently focusing their efforts in nanotechnology to address issues relevant to food and nutrition. Nanoemulsion technology is particularly suited for the fabrication of encapsulating systems for functional compounds as it prevents their degradation and improves their bioavailability. This review focuses on nanoemulsions and provides an overview of the production methods, materials used (solvents, emulsifiers and functional ingredients) and of the current analytical techniques that can be used for the identification and characterization of nanoemulsions. Finally, nanotechnological applications in foods currently marketed are reported.M.A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal)
Erratum to Nanoemulsions for Food Applications: Development and Characterization (Food and Bioprocess Technology, (2012), 5, (854-867), 10.1007/s11947-011-0683-7)
Artigo completo publicado na revista "Food and Bioprocess Technology." 5:3 (2012) 854-867 e disponível no RepositóriUM em http://hdl.handle.net/1822/22397Where it reads:
2. Production of nanoemulsions
2.1. High-energy approaches
• Ultrasound – when two immiscible liquids are submitted to high frequency sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation.
It should be read:
2. Production of nanoemulsions
2.2. High-energy approaches
• Ultrasound – when two immiscible liquids are submitted to high intensity sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation
Surface Architecture of Histoplasma Capsulatum
The dimorphic fungal pathogen Histoplasma capsulatum is the most frequent cause of clinically significant fungal pneumonia in humans. H. capsulatum virulence is achieved, in part, through diverse and dynamic alterations to the fungal cell surface. Surface components associated with H. capsulatum pathogenicity include carbohydrates, lipids, proteins, and melanins. Here, we describe the various structures comprising the cell surface of H. capsulatum that have been associated with virulence and discuss their involvement in the pathobiology of disease
A INSTABILIDADE DO GÊNERO CONTOS DE FADA: RETEXTUALIZAÇÕES DE CHAPEUZINHO VERMELHO
Este trabalho busca entender as interpretações sobre as quais se baseiam quatro traduções e uma adaptação do Chapeuzinho Vermelho de Charles Perrault, texto cuja estrutura narrativa e cujas particularidades estilísticas não se mostram inteiramente conformes aos modelos correntemente estabelecidos para o gênero conto de fadas. No intuito de explorar as interseções possíveis entre os estudos de tradução e a linguística textual, esta pesquisa fundamenta-se no conceito de retextualização proposto por Travaglia (2003) e na teoria da relevância de Wilson & Sperber (2004). Os problemas centrais aqui abordados se referem à maneira como fatores socioculturais influenciam os gêneros textuais e ao uso da adaptação como meio de produzir a equivalência. Tentou-se verificar a que ponto o paratexto constitui uma via de acesso às condições de elaboração da retextualização, como a priorização de certos traços semânticos permitiu o estabelecimento de um significado e em que grau esse processo é afetado pelo enquadramento genérico do texto-fonte. Na discussão proposta, destacam-se os aportes do interacionismo sociodiscursivo de Bronckart (2006) e de outros campos do saber, como os estudos literários e a história, com Genette (2002), Shavit (1986), Hutcheon (2006), Ariès (1973) e Badinter (2010)
Feasibility Analysis of the Solar Energy System in Civil Construction
The use of clean energy from renewable natural resources, replacing what is commonly used is seen as a solution to environment preservation and cost savings with energy generation and distribution. Therefore, the use of solar irradiation for the generation of electric energy is a viable option for regions that present climatic conditions favorable to this technology, as the state of Tocantins does. It is analyzed the feasibility of the energy generation system capable of supplying a building of up to 50m² with monthly consumption of 800kWh using the solar potential of the region. Following the norm that regulates the micro generation of energy in the country, according to the regulatory agency (ANEEL), presenting the components of the system and punctuating the advantages of its implementation. With a survey of energy costs based on the value determined by the concessionaire and the feasibility of deploying solar energy according to the monthly solar irradiation in conjunction with the equipment costs of the system. According to the results obtained from the method of implantation of the system, which is compact and flexible and capable of suiting any existing building structure, which allows a lifespan of close to 25 years, presenting a return on investment in 60 months of operation and providing a 75% reduction in the monthly energy bill, disregarding that this percentage may increase according to possible tariff readjustments. Being a clean energy that causes very low environmental impact in relation to the other methods commonly
Magnetic Field Effects on the Head Structure of Protostellar Jets
We present the results of 3-D SPMHD numerical simulations of
supermagnetosonic, overdense, radiatively cooling jets. Two initial magnetic
configurations are considered: (i) a helical and (ii) a longitudinal field. We
find that magnetic fields have important effects on the dynamics and structure
of radiative cooling jets, especially at the head. The presence of a helical
field suppresses the formation of the clumpy structure which is found to
develop at the head of purely hydrodynamical jets. On the other hand, a cooling
jet embedded in a longitudinal magnetic field retains clumpy morphology at its
head. This fragmented structure resembles the knotty pattern commonly observed
in HH objects behind the bow shocks of HH jets. This suggests that a strong
(equipartition) helical magnetic field configuration is ruled out at the jet
head. Therefore, if strong magnetic fields are present, they are probably
predominantly longitudinal in those regions. In both magnetic configurations,
we find that the confining pressure of the cocoon is able to excite
short-wavelength MHD K-H pinch modes that drive low-amplitude internal shocks
along the beam. These shocks are not strong however, and it likely that they
could only play a secondary role in the formation of the bright knots observed
in HH jets.Comment: 14 pages, 2 Gif figures, uses aasms4.sty. Also available on the web
page http://www.iagusp.usp.br/preprints/preprint.html. To appear in The
Astrophysical Journal Letter
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