RESUMO
In the context of multidimensional structures, with the presence of a common factor and multiple specific or group factors, estimates of reliability require specific estimators. The use of classical procedures such as the alpha coefficient or omega total that ignore structural complexity are not appropriate, since they can lead to strongly biased estimates. Through a simulation study, the bias of six estimators of reliability in multidimensional measures was evaluated and compared. The study is complemented by an empirical illustration that exemplifies the procedure. Results showed that the estimators with the lowest bias in the estimation of the total reliability parameter are omega total, the two versions of greatest lower bound (GLB) and the alpha coefficient, which in turn are also those that produce the highest overestimation of the reliability of the general factor. Nevertheless, the most appropriate estimators, in that they produce less biased estimates of the reliability parameter of the general factor, are omega limit and omega hierarchical.
RESUMO
The Scale for the Assessment of Developmental Assets in the Neighborhood (SADAN) has shown acceptable psychometric properties for use in Spain and Chile. However, the original factor structure of five correlated factors and a second-order factor is not yet entirely clear. This study aimed to evaluate the scale's psychometric properties of reliability and validity in a sample of Chilean adolescents. A cross-sectional design was used, with a sample of 2638 students (female = 49.1%) with an average age of 15.79 years (SD = 1.35). The results obtained when evaluating different confirmatory factor models show that the best structure is that of five correlated factors. We carry out a multigroup factor analysis up to the level of scalar invariance. We applied this analysis to the following groups: sex, type of school, and age. We conclude that the original version of the scale can be used in the Chilean context with slight modifications as it is necessary to deepen the validity evidence with external criteria.
RESUMO
The development of technologies that combine the advantages of nanomedicine with natural medicine represents a versatile approach to improve the safety and efficacy of drugs. Glycyrrhizinic acid (GA) is a natural compound that has a wide range of biological activities for the treatment of diseases. To establish a safe nanotransport system for this drug, two different nanoparticles with glycyrrhizinic acid, solid lipid nanoparticles (SLN-GA) and polymeric nanoparticles (PNPS-GA) were elaborated to obtain nanostructure sizes between 200 and 300 nm. The nanoparticles were evaluated at concentrations of 1.25-100 µl/ml using the MARC-145 cell line to determine the effects on cell morphology, cellular structure (actin filaments) and cell viability (mitochondrial and lysosomal) at 24 and 72 h post-exposure. The safety range of the nanoparticles was 50 µl/ml, to determine that PNPs-GA had an optimal safety profile and no cytotoxic effects, as there was no evidence of changes in morphology, internal cellular structures (stress fibers and the cell cortex formed by actin filaments) or viability under the experimental concentrations and conditions employed.