Quantitative structure-retention relationship (QSRR) models were used to predict the retention time (t R ) of mycotoxins and fungal metabolites. Heuristic method and radial basis function neural networks (RBFNN) were utilized to construct the linear and nonlinear QSRR models, respectively. The optimal QSRR model was developed based on a 5-21-1 RBFNN architecture using molecular descriptors calculated from molecular structure alone. The RBFNN model gave a square of correlation coefficient (R 2 ) of 0.8709 and root mean square error of 1.2892 for the test set. This article provided a useful tool for predicting the t R of other mycotoxins when experiment data are unknown. Keywords:Heuristic method / LC-MS/MS / Mycotoxins and fungal metabolites / Quantitative structure-retention relationship / Radial basis function neural networks

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The current work focuses on the DFT calculation of the rational mechanism and catalytic activity of the gold(i)-catalyzed isotetradehydro-Diels–Alder cycloaddition of cyanamides and enamides to substituted 2,6-diaminopyridines.

Background Parkinsonism-related motor complaints are commonly seen in the elderly. Our study aimed to investigate the association among Parkinsonism-related motor complaints, cerebral small vessel disease and cerebrovascular risk factors in a community-dwelling population in a Chinese rural area.Methods Individuals who were 50 years old or older, were independently living, were well-functioning, and had no history of ischemic or hemorrhagic stroke, were included. Brain magnetic resonance imaging (MRI), quantified motor function assessment, and questionnaire screening for Parkinsonism-related motor complaints were performed. Clinical data including cerebrovascular risk factors were collected. In univariate analysis, Chi-square test and student t-test were used to compare dichotomous variables and continuous variables, respectively, between individuals with or without motor complaints. In multivariate analysis, binary Logistic regression models were generated to determine risk factors for Parkinsonism-related motor complaints. General linear models were used to compare motor parameters between individuals with or without motor complaints. Results In the final analysis, 854 people were included. Individuals with motor complaints had a longer time for finger taping (6.2s v.s. 5.6s, p = 0.006), and a longer time for 3m-walking(4.0s v.s. 3.6s, p = 0.034) than did those without motor complaints. Hypertension was associated with motor complaints (odds ratio, 1.82; 95% confidence interval [CI], [1.21, 2.73]; p = 0.004). Age was not associated with motor complaints; none of the neuroimaging markers of cerebral small vessel disease was associated with motor complaints. Conclusion Hypertension is associated with Parkinsonism-related motor complaints. Better management of hypertension may prevent mobility limitation in the elderly. The questionnaire that we used for Parkinsonism is not suitable for screening small vessel disease in a community-dwelling population.