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Search Results: 1 - 10 of 175454 matches for " Pedro F Ferreira "
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Politics in trauma times: of subjectivity, war, and humanitarian intervention
Maria Jo?o Ferreira,Pedro F. Marcelino
Ethics & Global Politics , 2011, DOI: 10.3402/egp.v4i2.5984
Abstract:
How Anisotropic is our Universe?
Emory. F. Bunn,Pedro Ferreira,Joseph Silk
Physics , 1996, DOI: 10.1103/PhysRevLett.77.2883
Abstract: Large-scale cosmic microwave background anisotropies in homogeneous, globally anisotropic cosmologies are investigated. We perform a statistical analysis in which the four-year data from the Cosmic Background Explorer satellite is searched for the specific anisotropy patterns predicted by these models and thereby set definitive upper limits on the amount of shear, $(\sigma/H)_0$ and vorticity, $(\omega/H)_0$, which are orders of magnitude stronger than previous constraints. We comment on how these results might impact our understanding of primordial global anisotropy.
Myocardial first-pass perfusion imaging with hybrid-EPI: frequency-offsets and potential artefacts
Pedro F Ferreira, Peter D Gatehouse, David N Firmin
Journal of Cardiovascular Magnetic Resonance , 2012, DOI: 10.1186/1532-429x-14-44
Abstract: Numerical and phantom simulations were used to illustrate the effects of frequency-offsets and non-uniform magnitude modulation with this sequence in a typical perfusion protocol. In vivo data was post-processed to analyse the h-EPI’s sensitivity to the frequency-offsets.The centric phase-order was shown to be highly sensitive to frequency-offsets due to its symmetrical phase slope. Resulting artefacts include blurring, and splitting of the image into two identical copies along the phase-encode direction. It was also shown that frequency-offsets can introduce signal loss and ghosting of the right ventricle signal into the myocardium. The in vivo results were confirmed by numerical and phantom simulations. Magnitude modulation effects were found to be small.Imaging first-pass myocardial perfusion with an hybrid centric echo-planar-imaging sequence can be corrupted with ghosting and splitting of the image due to frequency-offsets.
Cosmic Strings in an Open Universe with Baryonic and Non-Baryonic Dark Matter
Pedro Ferreira
Physics , 1994, DOI: 10.1103/PhysRevLett.74.3522
Abstract: We study the effects of cosmic strings on structure formation in open universes. We calculate the power spectrum of density perturbations for two class of models: one in which all the dark matter is non baryonic (CDM) and one in which it is all baryonic (BDM). Our results are compared to the 1 in 6 IRAS QDOT power spectrum. The best candidates are then used to estimate $\mu$, the energy per unit length of the string network. Some comments are made on mechanisms by which structures are formed in the two theories.
Valida??o e análise da precis?o da vers?o em português do Needs of Parents Questionnaire
Ferreira, Pedro L.;Melo, Elsa;Reis, Gina;Mello, Débora F.;
Jornal de Pediatria , 2010, DOI: 10.1590/S0021-75572010000300010
Abstract: objective: to describe the procedures followed for the validation and reliability analysis of the portuguese version of the needs of parents questionnaire in the context of pediatric hospitalization in portugal. methods: this is a descriptive study based on procedures for the cultural and linguistic adaptation of health measurement tools. the validation was performed on a sample of 870 parents of hospitalized children in pediatrics departments from four hospitals in portugal, with ages ranging from 2 days to 18 years. content validity was assured by two cognitive debriefing meetings, separately organized with parents and staff. the reliability of the portuguese version was assessed through reproducibility tests and internal consistency computation. results: using cronbach's alpha, results from the cognitive debriefing and internal consistency scores were similar to those obtained by the authors of the original version and good for the three subscales, allowing us to state that the questionnaire has the adequate psychometric properties to measure parents' needs. it was well accepted by parents, who valued all needs, especially the need to trust the care provided to their child when they are not present, as well as the need to be trusted and the need for information. conclusions: the questionnaire proved to be a valid and reliable measurement instrument to assess the needs of parents during their pediatric hospitalizations. the portuguese version of the needs of parents questionnaire has been validated.
Optimización de la Concentración de L-Cisteína para la producción de 1,3-Propanodiol por una vía Biotecnológica
Ferreira,Tatiana F; Ribeiro,Roberta dos R; Matos,Pedro M; Coelho,Maria Alice Z;
Información tecnológica , 2013, DOI: 10.4067/S0718-07642013000100006
Abstract: glycerol was converted into 1,3-propanediol (1,3-pdo) using citrobacter freundii atcc 8090. 1,3-pdo is a bifunctional molecule that can be used in many applications, being of great commercial interest. the most recent route used for the production of this compound is through biotechnology using some micro-organisms capable of anaerobically converting glycerol into 1,3-pdo. the conversion done makes it necessary the addition of cysteine ??to the culture medium. five experiments were performed with cysteine at five concentrations to verify which is the optimum concentration that does not affect conversion of glycerol into 1,3-pdo. the concentrations used were 0.05, 0.10, 0.15, 0.20 and 0.25 gl-1. the yields were 15, 20, 26, 35 and 28 % respectively. according to the results it is concluded that the optimum cysteine concentration ??for 1,3-pdo production is 0.20 g.l-1.
Utiliza??o do D-manitol em síntese organica
Oliveira, Pedro S. M. de;Ferreira, Vitor F.;Souza, Marcus Vinicius N. de;
Química Nova , 2009, DOI: 10.1590/S0100-40422009000200031
Abstract: d-mannitol is used in several fields including food, pharmaceuticals, cosmetics and textiles being an important carbohydrate found widespread in nature. due to its chirality, it is largely used in organic synthesis with several applications, such as ligands, polymers, chiral pool, for preparation of small chiral building blocks, key intermediates in total synthesis. in this context, the aim of this review is to highlights recent applications of d-mannitol, especially in total synthesis.
Cirurgia do contorno corporal no paciente após perda ponderal maci?a: experiência de três anos em hospital público secundário
Orpheu, Simone Cristina;Coltro, Pedro Soler;Scopel, Gean Paulo;Saito, Fábio Lopes;Ferreira, Marcus Castro;
Revista da Associa??o Médica Brasileira , 2009, DOI: 10.1590/S0104-42302009000400018
Abstract: objective: to present the clinical-surgical three year-experience related to body contour surgery in the massive weight loss patient, performed by the plastic surgery team of the sapopemba state hospital. methods: retrospective study performed at the sapopemba state hospital, linked to the "hospital das clínicas" of the university of s?o paulo school of medicine, from july 2005 to july 2008. a total of 98 patients was operated, whose morbid obesity had been treated by bariatric surgery, after success of the technique, or weight loss by non-surgical method. exclusion criteria were smoking, gestational intent and weight instability. stable weight for at least 6 months after satisfactory weight loss was required from patients. results: of the 98 operated patients, 97% were female, with mean age of 40.5 years and the weight loss method was the surgery in 88% of cases. from 177 plastic surgeries performed, 46% were abdominoplasty, followed by mammaplasty (15%), thigh suspension (13%) and brachioplasty (12%). mean hospital stay was of two days and the main diagnosed complications were: seroma (28%), minor necrosis/dehiscences (18%), major necrosis/dehiscences (4%), hematomas (4%), superficial thrombophlebitis from the saphena vein (2%) and deep venous thrombosis (1%). conclusion: an increasing demand for surgeries to improve body contour after massive weight loss has been detected. plastic surgeons must know the clinical peculiarities and higher risk of complications of these patients, control their expectations, analyze results and engage in a continued investigation to improve surgical techniques.
Reproducibility of in-vivo diffusion tensor cardiovascular magnetic resonance in hypertrophic cardiomyopathy
McGill Laura-Ann,Ismail Tevfik F,Nielles-Vallespin Sonia,Ferreira Pedro
Journal of Cardiovascular Magnetic Resonance , 2012, DOI: 10.1186/1532-429x-14-86
Abstract: Background Myocardial disarray is an important histological feature of hypertrophic cardiomyopathy (HCM) which has been studied post-mortem, but its in-vivo prevalence and extent is unknown. Cardiac Diffusion Tensor Imaging (cDTI) provides information on mean intravoxel myocyte orientation and potentially myocardial disarray. Recent technical advances have improved in-vivo cDTI, and the aim of this study was to assess the interstudy reproducibility of quantitative in-vivo cDTI in patients with HCM. Methods and results A stimulated-echo single-shot-EPI sequence with zonal excitation and parallel imaging was implemented. Ten patients with HCM were each scanned on 2 different days. For each scan 3 short axis mid-ventricular slices were acquired with cDTI at end systole. Fractional anisotropy (FA), mean diffusivity (MD), and helix angle (HA) maps were created using a cDTI post-processing platform developed in-house. The mean ± SD global FA was 0.613 ± 0.044, MD was 0.750 ± 0.154 × 10-3 mm2/s and HA was epicardium 34.3 ± 7.6°, mesocardium 3.5 ± 6.9° and endocardium 38.9 ± 8.1°. Comparison of initial and repeat studies showed global interstudy reproducibility for FA (SD = ± 0.045, Coefficient of Variation (CoV) = 7.2%), MD (SD = ± 0.135 × 10-3 mm2/s, CoV = 18.6%) and HA (epicardium SD = ± 4.8°; mesocardium SD = ± 3.4°; endocardium SD = ± 2.9°). Reproducibility of FA was superior to MD (p = 0.003). Global MD was significantly higher in the septum than the reference lateral wall (0.784 ± 0.188 vs 0.750 ± 0.154 x10-3 mm2/s, p < 0.001). Septal HA was significantly lower than the reference lateral wall in all 3 transmural layers (from 8.3° to 10.4°, all p < 0.001). Conclusions To the best of our knowledge, this is the first study to assess the interstudy reproducibility of DTI in the human HCM heart in-vivo and the largest cDTI study in HCM to date. Our results show good reproducibility of FA, MD and HA which indicates that current technology yields robust in-vivo measurements that have potential clinical value. The interpretation of regional differences in the septum requires further investigation.
Optimización de la Concentración de L-Cisteína para la producción de 1,3-Propanodiol por una vía Biotecnológica Optimization of L-Cysteine Concentration to produce 1,3-Propanediol by a Biotechnological route
Tatiana F Ferreira,Roberta dos R Ribeiro,Pedro M Matos,Maria Alice Z Coelho
Información Tecnológica , 2013,
Abstract: Se ha realizado la conversión de glicerol en 1,3-propanodiol (1,3-PDO) usando la cepa Citrobacter freundii ATCC 8090. El 1,3-PDO es una molécula bifuncional que puede ser utilizada para muchas aplicaciones, siendo así de gran interés comercial. Una ruta más reciente para la producción de este compuesto es la vía biotecnológica utilizando algunos microorganismos capaces de convertir anaeróbicamente glicerol en 1,3-PDO. La conversión realizada hace necesaria la adición de cisteína al medio de cultivo. Se realizaron cinco experimentos con cinco concentraciones de cisteína con el fin de verificar cuál es la menor concentración posible que no afecta la conversión de glicerol en 1,3-PDO. Las concentraciones utilizadas fueron 0,05; 0,10; 0,15; 0,20 y 0,25 g.L-1. Los rendimientos fueron 15, 20, 26, 35 y 28 % respectivamente. De acuerdo a los resultados se concluye que la concentración óptima de cisteína para la producción de 1,3-PDO es 0,20 g.L-1. Glycerol was converted into 1,3-propanediol (1,3-PDO) using Citrobacter freundii ATCC 8090. 1,3-PDO is a bifunctional molecule that can be used in many applications, being of great commercial interest. The most recent route used for the production of this compound is through biotechnology using some micro-organisms capable of anaerobically converting glycerol into 1,3-PDO. The conversion done makes it necessary the addition of cysteine to the culture medium. Five experiments were performed with cysteine at five concentrations to verify which is the optimum concentration that does not affect conversion of glycerol into 1,3-PDO. The concentrations used were 0.05, 0.10, 0.15, 0.20 and 0.25 gL-1. The yields were 15, 20, 26, 35 and 28 % respectively. According to the results it is concluded that the optimum cysteine concentration for 1,3-PDO production is 0.20 g.L-1.
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