Developing a Synthetic Approach with Thermoregulated Phase-Transfer Catalysis: Facile Access to Metal-Mediated Living Radical Polymerization of Methyl Methacrylate in Aqueous/Organic Biphasic System

A novel strategy via thermoregulated phase-transfer catalysis (TRPTC) to separating catalyst in aqueous/organic biphasic system has been successfully established in a copper-mediated activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP) of methyl methacrylate (MMA), using a thermoresponsive PEG-supported dipyridyl ligand (PSDL) as the ligand and an alkyl pseudohalogen 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) as the initiator. The catalyst complex can transfer into the organic phase from initial catalyst aqueous solution at the reaction temperature (90 °C) to catalyze the homogeneous polymerization of MMA and then retransfer into the aqueous solution from the organic phase to separate the catalyst from the polymerization solution once cooled to room temperature (25 °C) while remaining well-controlled product (PMMA) in organic layer. In addition, the polymerization can be conducted in the presence of a limited amount of air, which not only does not sacrifice the controllability over polymerization but also can recycle the catalyst just by a simple change of the temperatures effectively

Algorithm for Detection and Quantification of Hyperreflective Dots on Optical Coherence Tomography in Diabetic Macular Edema

Purpose: To develop an algorithm to detect and quantify hyperreflective dots (HRDs) on optical coherence tomography (OCT) in patients with diabetic macular edema (DME).Materials and Methods: Twenty OCTs (each OCT contains 128 b scans) from 20 patients diagnosed with DME were included in this study. Two types of HRDs, hard exudates and small HRDs (hypothesized to be activated microglia), were identified and labeled independently by two raters. An algorithm using deep learning technology was developed based on input (in total 2,560 OCT b scans) of manual labeling and differentiation of HRDs from rater 1. 4-fold cross-validation was used to train and validate the algorithm. Dice coefficient, intraclass coefficient (ICC), correlation coefficient, and Bland–Altman plot were used to evaluate agreement of the output parameters between two methods (either between two raters or between one rater and proposed algorithm).Results: The Dice coefficients of total HRDs, hard exudates, and small HRDs area of the algorithm were 0.70 ± 0.10, 0.72 ± 0.11, and 0.46 ± 0.06, respectively. The correlations between rater 1 and proposed algorithm (range: 0.95–0.99, all p < 0.001) were stronger than the correlations between the two raters (range: 0.84–0.96, all p < 0.001) for all parameters. The ICCs were higher for all the parameters between rater 1 and proposed algorithm (range: 0.972–0.997) than those between the two raters (range: 0.860–0.953).Conclusions: Our proposed algorithm is a good tool to detect and quantify HRDs and can provide objective and repeatable information of OCT for DME patients in clinical practice and studies