Design, synthesis and in vitro antifungal activity of 3-substituted-methylenechroman-4-ones / 药学学报

Substituted phenols as the starting materials were transformed into substituted chromanones by substitution reaction and cyclization reaction, and then 3-(hydroxymethylene)chroman-4-ones were synthesized from substituted chromanones by condensation reaction; at last, the target compounds were synthesized from 3-(hydroxymethylene)chroman-4-ones by chlorination reaction. Their structures were confirmed by 1H NMR and MS. The antifungal activity of the target compounds in vitro was measured by consecutive double dilution, and the result of antifungal experiment indicated that the target compounds had good antifungal action on most fungi tested in vitro. The MIC value of compounds 4c, 4e, 4g and 4h on M. gypseum is 1 microg x mL(-1), better than fluconazole and amphotericin B.

Study on a back propogation neural network-based predictive model for prevalence of birth defect / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the value of a back propogation (BP) network on prediction of birth defect and to give clues on its prevention.</p><p><b>METHODS</b>Data of birth defect in Shenyang from 1995 to 2005 were used as a training set to predict the prevalence rate of birth defect. Neural network tools box of Software MATLAB 6.5 was used to train and simulate BP Artificial Neural Network.</p><p><b>RESULTS</b>When using data of the year 1995-2003 to predict the prevalence rate of birth defect in 2004-2005, the results showed that: the fitting average error of prevalence rate was 1.34%, RNL was 0.9874, and the prediction of average error was 1.78%. Using data of the year 1995-2005 to predict the prevalence rate of birth defect in 2006-2007, the results showed that: the fitting average error was 0.33%, RNL was 0.9954, the prevalence rates of birth defect in 2006-2007 were 11.00% and 11.29%.</p><p><b>CONCLUSION</b>Compared to the conventional statistics method, BP not only showed better prediction precision, but had no limit to the type or distribution of relevant data, thus providing a powerful method in epidemiological prediction.</p>