6 resultados para Database search
em Reposit
Resumo:
A esclerose múltipla (EM) é a doença crónica neurológica que mais afeta adultos jovens; em 80% dos casos, a doença progride para situações de níveis variados de incapacidade, o que torna necessário avaliar a qualidade de vida (QV) desses indivíduos. O objetivo desta revisão foi localizar estudos que avaliam a QV em indivíduos com EM, identificando os instrumentos utilizados e suas características psicométricas. Foram consultadas as bases Psycinfo, Psycarticles, Psycbooks, Psychology & Behavioral Science Collection, EJS E-Journal, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Medline, e Academic Search Complete, utilizando os descritores 'multiple sclerosis' e 'quality of life', para localizar artigos publicados no período 1997-2007. Foram selecionados 1.376 artigos e, após a leitura dos resumos, excluídos os referentes a instrumentos que não tinham boas características psicométricas e/ou eram pouco referenciados. Foram encontrados 461 artigos, dos quais 267 usaram instrumentos genéricos e 194 específicos para a EM. Dos 7 instrumentos (2 genéricos, 5 específicos) com boas características psicométricas utilizados pelos estudos consultados, o mais usado é o SF-36 (em 237 estudos). Todos os instrumentos têm validade verificada e apresentam grau elevado de confiabilidade, podendo ser utilizados para avaliação da qualidade de vida de pacientes com EM tanto em pesquisa quanto na clínica. ABSTRACT - Multiple sclerosis (MS) is the chronic neurological disease that most affects young adults; 80% of patients experience a transition towards persistent disability, hence the need to assess their quality of life (QoL). The aim of the study was to review studies that assess QoL in patients with multiple sclerosis, inquiring on the instruments used and their psychometric features. Articles published from 1997 through 2007 were searched for by means of key words 'multiple sclerosis' and 'quality of life' in databases Psycinfo, Psycarticles, Psycbooks, Psychology & Behavioral Science Collection, EJS E-Journal, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Medline, and Academic Search Complete. From the 1,376 studies found, after abstract reading those that reported on instruments with poor psychometric properties and/or were little referred were excluded. A total of 461 articles were selected, of which 267 reported using generic instruments and 194, MS-specific ones. Among the 7 instruments reported by the studies as having good psychometric characteristics (2 generic, five MS-specific), the most used is the SF-36 (by 237 studies). All instruments have shown adequate psychometric properties and a high degree of reliability, hence may be used to assess QoL in subjects with multiple sclerosis both in clinic and research.
Resumo:
We study the implications of the searches based on H -> tau(+)tau-by the ATLAS and CMS collaborations on the parameter space of the two-Higgs-doublet model (2HDM). In the 2HDM, the scalars can decay into a tau pair with a branching ratio larger than the SM one, leading to constraints on the 2HDM parameter space. We show that in model II, values of tan beta > 1.8 are definitively excluded if the pseudoscalar is in the mass range 110 GeV < m(A) < 145 GeV. We have also discussed the implications for the 2HDM of the recent dimuon search by the ATLAS collaboration for a CP-odd scalar in the mass range 4-12 GeV.
Resumo:
Brain dopamine transporters imaging by Single Emission Tomography (SPECT) with 123I-FP-CIT (DaTScanTM) has become an important tool in the diagnosis and evaluation of Parkinson syndromes.This diagnostic method allows the visualization of a portion of the striatum – where healthy pattern resemble two symmetric commas - allowing the evaluation of dopamine presynaptic system, in which dopamine transporters are responsible for dopamine release into the synaptic cleft, and their reabsorption into the nigrostriatal nerve terminals, in order to be stored or degraded. In daily practice for assessment of DaTScan TM, it is common to rely only on visual assessment for diagnosis. However, this process is complex and subjective as it depends on the observer’s experience and it is associated with high variability intra and inter observer. Studies have shown that semiquantification can improve the diagnosis of Parkinson syndromes. For semiquantification, analysis methods of image segmentation using regions of interest (ROI) are necessary. ROIs are drawn, in specific - striatum - and in nonspecific – background – uptake areas. Subsequently, specific binding ratios are calculated. Low adherence of semiquantification for diagnosis of Parkinson syndromes is related, not only with the associated time spent, but also with the need of an adapted database of reference values for the population concerned, as well as, the examination of each service protocol. Studies have concluded, that this process increases the reproducibility of semiquantification. The aim of this investigation was to create and validate a database of healthy controls for Dopamine transporters with DaTScanTM named DBRV. The created database has been adapted to the Nuclear Medicine Department’s protocol, and the population of Infanta Cristina’s Hospital located in Badajoz, Spain.
Resumo:
The DatScanTM and its Semiquantification (SQ) can provide advantages in the diagnosis of Parkinsonian Syndromes (PS). To improve the SQ is recommended the creation of adapted database (DB) with reference values for the Nuclear Medicine Departments. Previously to this work was created a adapted database (DBRV) to Nuclear Medicine Department's protocol and population of Infanta Cristina's Hospital located in Badajoz, for patients between the ages of 60 and 75, and reference values of the SQ were calculated. Aim: To evaluate the discrimination capacity of a department's adapted DB reference's values of healthy controls for DatScanTM.
Resumo:
Locating and identifying points as global minimizers is, in general, a hard and time-consuming task. Difficulties increase in the impossibility of using the derivatives of the functions defining the problem. In this work, we propose a new class of methods suited for global derivative-free constrained optimization. Using direct search of directional type, the algorithm alternates between a search step, where potentially good regions are located, and a poll step where the previously located promising regions are explored. This exploitation is made through the launching of several instances of directional direct searches, one in each of the regions of interest. Differently from a simple multistart strategy, direct searches will merge when sufficiently close. The goal is to end with as many direct searches as the number of local minimizers, which would easily allow locating the global extreme value. We describe the algorithmic structure considered, present the corresponding convergence analysis and report numerical results, showing that the proposed method is competitive with currently commonly used global derivative-free optimization solvers.
Resumo:
In order to correctly assess the biaxial fatigue material properties one must experimentally test different load conditions and stress levels. With the rise of new in-plane biaxial fatigue testing machines, using smaller and more efficient electrical motors, instead of the conventional hydraulic machines, it is necessary to reduce the specimen size and to ensure that the specimen geometry is appropriate for the load capacity installed. At the present time there are no standard specimen's geometries and the indications on literature how to design an efficient test specimen are insufficient. The main goal of this paper is to present the methodology on how to obtain an optimal cruciform specimen geometry, with thickness reduction in the gauge area, appropriate for fatigue crack initiation, as a function of the base material sheet thickness used to build the specimen. The geometry is optimized for maximum stress using several parameters, ensuring that in the gauge area the stress distributions on the loading directions are uniform and maximum with two limit phase shift loading conditions (delta = 0 degrees and (delta = 180 degrees). Therefore the fatigue damage will always initiate on the center of the specimen, avoiding failure outside this region. Using the Renard Series of preferred numbers for the base material sheet thickness as a reference, the reaming geometry parameters are optimized using a derivative-free methodology, called direct multi search (DMS) method. The final optimal geometry as a function of the base material sheet thickness is proposed, as a guide line for cruciform specimens design, and as a possible contribution for a future standard on in-plane biaxial fatigue tests