ABSTRACT
RESUMEN La conducta suicida es un problema de salud pública mundial, y una población en la que se presentan altos índices de prevalencia es la de estudiantes de Medicina, especialmente en el componente de ideación. Diversos modelos han intentado explicarla, pero son pocos los estudios inferenciales en población colombiana. Los modelos de ecuaciones estructurales utilizados en ciencias sociales resultan apropiados para explicar este problema y su poder analítico permite realizar generalizaciones con cierto grado de precisión. Estos análisis requieren una gran cantidad de datos para una estimación robusta, lo que limita su utilidad cuando hay restricciones para acceder a los datos, como sucede actualmente a causa de la COVID-19, y una cuestión que destaca en estos modelos es la evaluación del ajuste. Mediante un conjunto de 1.200 datos simulados, se encontró un adecuado ajuste del modelo a los datos (x2 524) = 1.732, 300; p< 0, 001; CFI = 0,97; GFI0= 0,97; TLI = 0,97; RMSEA = 0,04 [0,042-0,046]; SRMR = 0,06) para los predictores depresión y carga percibida, cuyos análisis se realizaron en el programa JASP. Se discute el papel de la pertenencia frustrada, la conveniencia del instrumento para evaluarla y consideraciones de seguimiento, evaluación e intervención de la ideación suicida en estudiantes de Medicina. © 2020 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España, S.L.U. Todos los derechos reservados.
ABSTRACT Suicidal behavior is a global public health problem, and one population group with high prevalence rates is medical students, especially in the ideation component. Various models have tried to explain it, but there are few inferential studies in the Colombian population. The structural equation models used in controlled social sciences to explain this problem and their analytical power allow generalizations to be made with a certain degree of precision. These analyses require a large amount of data for robust estimation, which limits their usability when there are restrictions to access the data, as is the case today due to Covid-19, and a question that stands out in these models is the evaluation of the fit. Through a set of 1,200 simulated data, an appropriate model fit was found (x2 524) = 1.732, 300; p< 0, 001, CFI = 0.97, GFI = 0.97, TLI = 0.97, RMSEA = 0.04[0.042-0.046], SRMR = 0.06) for the predictors of depression and perceived burdensomeness, which were analyzed using the JASP pro-gram. The role of thwarted belongingness is discussed, as well as the appropriateness of the assessment instrument used to evaluate it an considerations regarding suicidal ideation monitoring, evaluation and intervention in medical students.
ABSTRACT
Objective: To simulate the kinematics of drug particles in two kinds of dry powder inhalation devices for Rehmanniae Radix oligosaccharide dry powder inhalation (RRODPI) by computational fluid dynamics (CFD), and to compare simulation results with the in vitro deposition results in order to verify the accuracy of the results. Methods: NGI was used to carry out in vitro deposition experiments, and the relative experiment data were obtained. UGNX 10.0 software was adopted to establish three-dimensional models of two kinds of dry powder inhalation devices according to their actual sizes, and then the models were imported into ICEM CFD software to divide mesh. After checking mesh quality, mesh was imported to Fluent software and the related parameters were set. When the data was in steady state after iteration and convergence, the data analysis was carried out; Finally the kinematics results of drug particles at three kinds of particle sizes in two kinds of dry powder inhalation devices were gained. The kinematics results were compared with the in vitro deposition results to verify the simulation results. Results: In vitro deposition experiment results showed that the effective deposition rate in twister was higher than that in osmohaler. CFD results showed that drug particles at different sizes in twister could all reach the outlet but for drug particles in osmohaler, it could not reach the outlet at a certain range of sizes. The two results showed that twister was more suitable for the dry powder inhaler device of RRODPI. Conclusion: It is comparatively intuitive to use CFD to carry out the kinematics simulation of drug particles in two kinds of dry powder inhalation devices and the result is consistent with the in vitro deposition experiment results, which can well predict the motion state of drug particles in the two dry powder inhalation devices.
ABSTRACT
Researchers dealing with the task of estimating locations of individuals on continuous latent variables may rely on several statistical models described in the literature. However, weighting costs and benefits of using one specific model over alternative models depends on empirical information that is not always clearly available. Therefore, the aim of this simulation study was to compare the performance of seven popular statistical models in providing adequate latent trait estimates in conditions of items difficulties targeted at the sample mean or at the tails of the latent trait distribution. Results suggested an overall tendency of models to provide more accurate estimates of true latent scores when using items targeted at the sample mean of the latent trait distribution. Rating Scale Model, Graded Response Model, and Weighted Least Squares Mean- and Variance-adjusted Confirmatory Factor Analysis yielded the most reliable latent trait estimates, even when applied to inadequate items for the sample distribution of the latent variable. These findings have important implications concerning some popular methodological practices in Psychology and related areas. (AU)
Pesquisadores interessados em estimar a localização de indivíduos em variáveis latentes contínuas podem se beneficiar de diversos modelos estatísticos disponíveis na literatura. Entretanto, ponderar os custos e os benefícios de usar um modelo em detrimento de outros depende de informações empíricas que nem sempre estão diretamente disponíveis. Em virtude disso, o objetivo deste estudo foi comparar o desempenho de sete modelos estatísticos populares quanto a proporcionar adequadas estimativas de traço latente em condições de itens com dificuldades condizentes com a distribuição latente amostral versus apenas condizentes com as caudas dessa distribuição. Os resultados sugeriram uma tendência de todos os modelos de proporcionar estimativas mais precisas ao serem usados itens adequados para o nível de traço latente da amostra. Os modelos da Teoria de Resposta ao Item Rating Scale e Graded Response e a análise fatorial confirmatória com estimação Weighted Least Squares Mean- and Variance-adjusted forneceram as estimativas mais fidedignas de traço latente, mesmo quando os itens utilizados, de fato, correspondiam ao nível latente de poucos casos da amostra. Os resultados possuem importantes implicações no que diz respeito a algumas práticas metodológicas populares na Psicologia e em áreas próximas. (AU)