Predicting participation of people with impaired vision in epidemiological studies

The characteristics of the target group and the design of an epidemiologic study, in particular the recruiting methods, can influence participation. People with vision impairment have unique characteristics because those invited are often elderly and totally or partially dependent on help to complete daily activities such as travelling to study sites. Therefore, participation of people with impaired vision in studies is less predictable than predicting participation for the general population.This study was supported by FCT (COMPETE/QREN) grant reference PTDC/DPT-EPI/0412/2012 in the context of the Prevalence and Costs of Visual Impairment in Portugal: a hospital based study (PCVIP-study). PLR is funded by FCT (COMPETE/QREN) grant reference SFRH/BD/119420/2016

Structural and theoretical-experimental physicochemical study of trimethoprim/randomly methylated-beta-cyclodextrin binary system

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Here we report the structural characterization, physicochemical study and molecular modeling of the inclusion complex of trimethoprim in randomly methylated beta-cyclodextrin. The phase-solubility diagram obtained at pH 7.0 exhibited a linear behavior for the RAMEB concentrations studied suggesting a 1:1 stoichiometry and absence of aggregation in solution. From stoichiometric determination by the continuous variation method we confirmed a 1:1 stoichiometry. To make a detailed characterization of the inclusion mode, spectroscopic measurements by infrared and 1D and 20 (1)H NMR spectroscopy provided evidence that the inclusion mode is characterized by inclusion of the trimethoxyphenyl ring in the cavity; interactions with methyl groups located in the border of the cavity were also detected. The structure proposed was also confirmed by semiempirical molecular modeling. (C) 2011 Elsevier Ltd. All rights reserved.3461727462751FinepCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FapitecCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Characterization, phase solubility and molecular modeling of alpha-cyclodextrin/pyrimethamine inclusion complex

An inclusion complex between the dihydrofolate reductase inhibitor pyrimethamine (PYR) and alpha-cyclodextrin (alpha-CD) was prepared and characterized. From the phase-solubility diagram, a linear increase of PYR solubility was verified as a function of alpha-CD concentration, suggesting the formation of a soluble complex. A 1: 1 host-guest stoichiometry can be proposed according to the job's plot, obtained from the difference of PYR fluorescence intensity in the presence and absence of alpha-CD. Differential scanning calorimetry (DSC) measurements provided additional evidences of complexation such as the absence of the endothermic peak assigned to the melting of the drug. The inclusion mode characterized by two-dimensional (1)H NMR spectroscopy (RCESY) involves penetration of the p-chlorophenyl ring into the alpha-CD cavity, in agreement to the orientation optimized by molecular modeling methods. (C) 2008 Elsevier B.V. All rights reserved.72116517