Search results for "Sample"

The efficacy of balneotherapy, mud therapy and spa therapy in patients with osteoarthritis: an overview of reviews.

2021

Osteoarthritis is a degenerative disease considered a leading cause of functional disability. Its treatment is based on a combination of pharmacological and non-pharmacological interventions, but the role of these latter is still debated. This overview of systematic reviews aimed at evaluating the short-term efficacy of different thermal modalities in patients with osteoarthritis. We searched PubMed, Scopus, CINHAL, Web of Science, ProQuest and the Cochrane Database of Systematic Reviews from inception until October 2020, with no language restrictions. We selected the following outcomes a priori: pain, stiffness and quality of life. Seventeen systematic reviews containing 27 unique relevant…

Analytical methods to determine cocaine contamination of banknotes from around the world

2008

Abstract The presence of cocaine in a significant number of UK pounds (Xxxx), Euros (€) and North American banknotes ($) in general circulation requires appropriate tools to do determinations. This article discusses the-state-of-the-art in the analysis of cocaine on banknotes. We summarize the usual extraction methods of currency samples and compare them, especially with respect to avoiding sample damage. We critically discuss analytical methods, namely gas chromatography (GC) and liquid chromatography (LC), capillary electrophoresis (CE), immunoassay, thermal desorption tandem mass spectrometry (TD-MS2) and ion-mobility spectrometry (IMS). We also review cocaine levels on banknotes around …

Fundamentals and applications of stir bar sorptive dispersive microextraction: A tutorial review

2021

Current trends in sample preparation focus on the miniaturization of the process resulting in what is known as microextraction techniques. Among them stir bar sorptive dispersive microextraction (SBSDME) is one of the most recent techniques. It was presented a few years ago as a hybrid microextraction technique that combines the principles of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE). This novel technique introduces, into the sample solution, a bar-shaped magnet coated with a magnetic (nano)material, which is maintained on the surface by magnetism. Once stirring starts, the competitive action between magnetism and rotational force is exploited. At low …

An adaptive-PCA algorithm for reflectance estimation from color images

2008

This paper deals with the problem of spectral reflectance estimation from color camera outputs. Because the reconstruction of such functions is an inverse problem, stabilizing the reconstruction process is highly desirable. One way to do this is to decompose reflectance function on a basis functions like PCA. The present work proposes an algorithm making PCA adaptive in reflectance estimation from a color camera output. We propose to adapt the PCA basis derivation by selecting, for each sample, the more relevant elements from the training set elements. The adaptivity criterion is achieved by a likelihood measurement. Finally, the spectral reflectance estimation results are evaluated with th…

Bayesian Inference for the Exponential Power Function Parameters

2008

This paper addresses the problem of obtaining the marginal posterior distributions, via Gibbs Sampler, for the parameters of the well-known generalized error distribution called Exponential Power Function (E.P.F.). This density represents a family of unimodal symmetric distributions with shapes varying from leptokurtic to platikurtic.

Un análisis bibliométrico en el área de la Medicina: colaboración científica entre Brasil y España (2002-2011)

2016

[EN]: This study analyzes the development of Spanish-Brazilian collaborative scientific production in the field of medical research between 2002 and 2011, identifying the most productive institutions, the proportion of researchers from each country and bi-lateral collaborative networks. Data were gathered from the Scopus database, which offers broad, international coverage of multidisciplinary research. A study sample of 1,121 original scientific articles signed by 13,906 researchers were retrieved, on the basis of which the annual growth rate of Spanish-Brazilian medical research was calculated. A remarkably high degree of internationalization was found, with 121 countries participating in…

Test-retest reliability of a new self reported comprehensive questionnaire measuring frequencies of different modes of adolescents commuting to schoo…

2009

Published version of an article from the journal: International Journal of Behavioral Nutrition and Physical Activity Article available from: http://www.ijbnpa.org/content/6/1/68 Background: Studies assessing active commuting to school usually use simple questionnaires, and often is mode of commuting reported with a single questionnaire item only. The purpose of the present study is to report the test-retest reliability of a newly developed comprehensive questionnaire on active commuting to school and work among 6thgrade school children and their parents in Norway. Methods: A total of 106 pupils and 77 parents completed a questionnaire two times, 14 days apart. The questionnaire consisted o…

Competing factor structures of the Rosenberg Self-Esteem Scale (RSES) and its measurement invariance across clinical and non-clinical samples

2017

Abstract Although several studies have investigated the factor structure of the Rosenberg Self-Esteem Scale (RSES), there are still disagreements about it. The present study assessed: a) the goodness of fit of nine competing factor models for the RSES using data from a clinical sample of 855 women with eating/weight disorders; and b) its measurement invariance across clinical and non-clinical (n = 943) samples. A bifactor model, with a general self-esteem factor, plus positive and negative method factors, provided a better fit with the data than alternative models. However, the results showed the high reliability of the general self-esteem factor, and a low reliability of the two method fac…

2013

Currently, a growing number of programs become available in statistical software for multiple imputation of missing values. Among others, two algorithms are mainly implemented: Expectation Maximization (EM) and Multiple Imputation by Chained Equations (MICE). They have been shown to work well in large samples or when only small proportions of missing data are to be imputed. However, some researchers have begun to impute large proportions of missing data or to apply the method to small samples. A simulation was performed using MICE on datasets with 50, 100 or 200 cases and four or eleven variables. A varying proportion of data (3% - 63%) was set as missing completely at random and subsequent…

Determination of phenytoin in plasma by molecularly imprinted solid-phase extraction.

2001

Abstract A molecularly imprinted polymer (MIP) using phenytoin as template and methacrylamide as the functional monomer was prepared. The selectivity was measured by comparing capacity factors of phenytoin and other structurally related compounds. The polymer was evaluated as a selective sorbent in molecularly imprinted solid-phase extraction (MISPE). Several washing solvents were tested to study their ability to disrupt the non-specific interactions occurring between the sample and the polymer matrix and the role of water in the recognition process was also investigated. It was shown that the key step of successful sample extraction is the right choice of the washing solvent. Plasma sample…