The photodynamic antimicrobial chemotherapy (PACT) activities of seven 1,3,5,7-tetramethyl-2,6-dibromoBODIPY dyes with 4-acetamidophenyl (2a), 2-iodophenyl (2b), 3-iodophenyl (2c), 4-iodophenyl (2d), 2-bromophenyl (2e), 5-bromothien-2-yl (2f), and methylphenyl ester (2g) meso-substituents were studied against Staphylococcus aureus through irradiation with a 530 nm Thorlabs M530L3 light emitting diode (LED) (110 mW.cm to identify structure-property relationships related to modifying the meso-substituent. Significant differences are observed in the log reduction values obtained with 1 M of 2a exhibiting the highest PACT activity with a value of 9.60 after 15 min of photoirradiation. In contrast, log reduction values < 1.20 were obtained after 60 min of photoirradiation for iodophenyl dyes 2b-2d. The data demonstrate that the singlet oxygen quantum yield of the dye is not the most important factor determining the PACT activity properties.
Introduction: Ultrasound estimated fetal weight is increasingly being used in the monitoring of fetal growth. Large systematic and random errors in estimated fetal weight have been reported; these may have an impact on the accuracy of fetal growth monitoring. The aim of this study was to attempt to evaluate these systematic and random errors by analysis of serial ultrasound data.
Methods: Ultrasound measurements and birthweights were retrospectively collected for 100 unselected patients who had undergone serial ultrasound. Birthweights were used to calculate expected fetal growth trajectories using a method for generating growth charts based on customised birthweights. Estimated fetal weight results were then compared with the expected growth trajectories to evaluate systematic and random differences.
Results: Incomplete measurement sets were excluded, reducing the number of scans to less than three for 13 subjects. A further 17 subjects with suspected pathological growth trajectories were excluded. The final analysis included 70 subjects with a total of 246 scans. The mean difference between estimated fetal weight and expected weight over three to six scans ranged from -17.5% to 38.3% with a mean of 8.4%, representing the systematic difference. The standard deviation of these differences ranged from 0.4% to 21% with a mean of 4.3%, representing random difference.
Conclusion: Systematic and random differences between estimated fetal weight and expected fetal weight are significant and make interpretation of fetal growth difficult. Further improvements to formulae and growth curves are required and audit of fetal measurements is essential to service improvement.