589 research outputs found

    The Behavioral Regulation in Exercise Questionnaire (BREQ-4): Psychometric evidence of introjected approach regulation in Portuguese health club exercisers

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    The assessment of motivation has been a key aspect to the understanding of exercise participation, and research grounded in self-determination theory has presented valid and reliable instruments for that purpose. Given the need to continually refine this latent construct, the present study aimed to translate, adapt, and psychometrically validate a subscale targeting the approach facet of introjection, and to test the pattern of associations between motives for practice, basic psychological needs satisfaction/frustration, and behavioral regulations encompassing the validated introjection subscale, in a sample of health club exercisers. For that purpose, two studies were developed with a total of 1216 health club exercisers. In Study I (n = 806), Confirmatory Factor Analysis and Exploratory Structural Equation Modeling analysis to test the motivational continuum encompassing the introjected approach subscale were performed. In Study II (n = 410) associations and structural models between intrinsic and extrinsic goal contents, basic psychological needs satisfaction and frustration, and behavioral regulations with the new subscale were tested. The correlated seven-factor model with 21 items in Study I displayed good psychometric properties (CFA: χ2 = 481.977 (168), p < .001, CFI = 0.936, TLI = 0.915, SRMR = 0.037, RMSEA = 0.048; ESEM: χ2 = 178.672 (84), p < .001, CFI = 0.980, TLI = 0.949, SRMR = 0.014, RMSEA = 0.037). The introjected approach regulation added to the preexisting factorial structure did not affect the validity and reliability of the instrument. The results from Study II supported a theoretically expected pattern of associations, in which the introjected regulation of approach is positioned between introjected avoidance and identified regulation along the motivational continuum. Additionally, path estimates depicted criterion validity for the new subscale. All in all, this work presents preliminary evidence for an introjected approach regulation subscale that can be used in health club practices for a better understanding of the motivational quality of exercise practice.info:eu-repo/semantics/publishedVersio

    Adaptation and validation of the Portuguese version of the regulation of eating behavior scale (REBSp)

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    The aim of present study was two-fold: i) to translate and adapt the Regulation of Eating Behavior Scale to Portuguese (REBSp), and ii) to analyze its psychometrics properties (factorial validity with gender invariance analyses, reliability and construct validity). The study sample was composed by 471 Portuguese participants (68.4% females) with a mean age of 30.5 years (SD = 11.2). Structural equation modeling was used to verify the psychometric properties of the scale using SPSS v. 23.0 and AMOS 24.0 software. The analysis showed that the Portuguese 24-item scale presented a good fit, achieving good reliability and convergent validity. Some issues arose with discriminant validity within autonomous and controlled regulations, discussed in light of the simplex pattern expected by self-determination theory literature. Additionally, the scale presented concurrent validity and evidence of gender measurement invariance. Latent mean analysis between genders showed that women presented higher means for intrinsic motivation and integrated regulation when compared to men. In conclusion, analyses suggest that the 24-item Portuguese version of REBS can be used safely to assess the eating regulation in both genders.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Chemical Functionalization of Cellulosic Materials — Main Reactions and Applications in the Contaminants Removal of Aqueous Medium

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    The cellulose is the most abundant biopolymer in the world and presents a higher chemical variability for presence of several hydroxyl groups. These hydroxyl groups allow surface modification of biomaterials, with insertion of several chemical groups which change cellulose characteristics. This natural biopolymer and its derivatives have been used a lot as adsorbent, from several contaminants of aqueous medium due to biocompatibility, chemical degradability, and variability. Therefore, this chapter has the objective to review the literature about several cellulose surfaces or cellulosic material (incorporation of carboxymethyl, phosphorus, carboxyl, amines, and sulfur), presenting the main characteristics of reactions and showing its adsorption in application of aqueous medium (metals, dyes, and drugs), locating the main interactions between biomaterial/contaminant

    Validação da bioimpedância elétrica por multifrequência em atletas

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    É reconhecida a importância de avaliar a composição corporal na população atlética. Para o efeito é preciso utilizar técnicas válidas na determinação dos principais componentes moleculares. A Densitometria Radiológica de Dupla Energia (DXA) é um método preciso e válido para avaliação de composição corporal. No entanto, a DXA é uma técnica ainda pouco acessível em contextos não laboratoriais. Desta forma, é importante utilizar técnicas mais simples e práticas como a bioimpedância eléctrica (BIA). No entanto poucos estudos validaram a BIA especialmente de multifrequência na avaliação da composição corporal em atletas. Assim, o objetivo desta investigação é testar a validade da BIA de multifrequência (Tanita, modelo MC-180) na determinação do conteúdo mineral ósseo (CMO), massa gorda (MG) e massa isenta de gordura e osso (MIGO) em atletas. Um total de 79 atletas (35 homens) foram avaliados pela BIA e pela DXA. Comparação de médias, coeficiente de correlação de concordância, regressão múltipla, e o método Bland-Altman foram realizados. A Tanita apresentou um poder explicativo de 76 %, 72%, 95% e 73% da variabilidade total observada a partir do método de referência para a MG (kg), MG (%), MIGO e CMO, respectivamente. O coeficiente de correlação de concordância para a MIGO apresentou uma força de concordância substancial de 0.927. Observaram-se limites de concordância relativamente elevados na estimativa dos vários componentes corporais. Em conclusão, a Tanita MC-180 é uma alternativa válida especialmente na estimação da massa isenta de gordura e de osso, num grupo de atletas. Contudo, devido aos limites de concordância obtidos na determinação das vários componentes este equipamento apresenta uma validade limitada na estimação individual da composição corporal. Palavras-chave: Atleta; Avaliação Física; Composição Corporal.It is recognized the importance of assessing body composition in athletic populations. Therefore, it is necessary to use valid techniques for the determination of the main molecular components. Dual-energy X-ray absorptiometry (DXA) is a precise and valid method for assessing body composition. However, DXA is still not available at the clinical and field settings. Thus, it is important to use simple techniques such as electrical bioimpedance analysis (BIA) but few studies validated this technique specifically multifrequency BIA in body composition assessment in athletes. Therefore, the aim of this research is to test the validity of multifrequency BIA (Tanita, Model MC-180) in the determination of bone mineral content (BMC), lean soft tissue (LST) and fat mass (FM) in athletes. A total of 79 elite athletes (35 males) were assessed by DXA and BIA. Comparison of means, concordance coefficient correlation, multiple regression and Bland-Altman analysis were performed. Tanita explained 76%, 72%, 95% and 73% of the total variability observed from the reference method for FM (kg), FM (%), LST and BMC, respectively. The concordance coefficient correlation for MIGO presented a substantial strength of agreement of 0,927. However, relatively larger limits of agreement were found between BIA and DXA for the several body components. These findings reveal that the Tanita MC-180 is a valid alternative, particularly in the estimation of LST, in a group of athletes. However, due to the limits of agreement obtained in the determination of the body components this equipment presents a more limited validity in the estimation of individual body composition. Key Words: Athletes; Physical Assessment; Body Composition

    Inhalation of the prodrug PI3K inhibitor CL27c improves lung function in asthma and fibrosis

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    PI3K activation plays a central role in the development of pulmonary inflammation and tissue remodeling. PI3K inhibitors may thus offer an improved therapeutic opportunity to treat non-resolving lung inflammation but their action is limited by unwanted on-target systemic toxicity. Here we present CL27c, a prodrug pan-PI3K inhibitor designed for local therapy, and investigate whether inhaled CL27c is effective in asthma and pulmonary fibrosis. Mice inhaling CL27c show reduced insulin-evoked Akt phosphorylation in lungs, but no change in other tissues and no increase in blood glycaemia, in line with a local action. In murine models of acute or glucocorticoid-resistant neutrophilic asthma, inhaled CL27c reduces inflammation and improves lung function. Finally, inhaled CL27c administered in a therapeutic setting protects from bleomycin-induced lung fibrosis, ultimately leading to significantly improved survival. Therefore, local delivery of a pan-PI3K inhibitor prodrug reduces systemic on-target side effects but effectively treats asthma and irreversible pulmonary fibrosis
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