BackgroundElectronic medical records provide large-scale real-world clinical data for use in developing clinical decision systems. However, sophisticated methodology and analytical skills are required to handle the large-scale datasets necessary for the optimisation of prediction accuracy. Myopia is a common cause of vision loss. Current approaches to control myopia progression are effective but have significant side effects. Therefore, identifying those at greatest risk who should undergo targeted therapy is of great clinical importance. The objective of this study was to apply big data and machine learning technology to develop an algorithm that can predict the onset of high myopia, at specific future time points, among Chinese school-aged children.Methods and findingsReal-world clinical refraction data were derived from electronic medical record systems in 8 ophthalmic centres from January 1, 2005, to December 30, 2015. The variables of age, spherical equivalent (SE), and annual progression rate were used to develop an algorithm to predict SE and onset of high myopia (SE ≤ −6.0 dioptres) up to 10 years in the future. Random forest machine learning was used for algorithm training and validation. Electronic medical records from the Zhongshan Ophthalmic Centre (a major tertiary ophthalmic centre in China) were used as the training set. Ten-fold cross-validation and out-of-bag (OOB) methods were applied for internal validation. The remaining 7 independent datasets were used for external validation. Two population-based datasets, which had no participant overlap with the ophthalmic-centre-based datasets, were used for multi-resource validation testing. The main outcomes and measures were the area under the curve (AUC) values for predicting the onset of high myopia over 10 years and the presence of high myopia at 18 years of age. In total, 687,063 multiple visit records (≥3 records) of 129,242 individuals in the ophthalmic-centre-based electronic medical record databases and 17,113 follow-up records of 3,215 participants in population-based cohorts were included in the analysis. Our algorithm accurately predicted the presence of high myopia in internal validation (the AUC ranged from 0.903 to 0.986 for 3 years, 0.875 to 0.901 for 5 years, and 0.852 to 0.888 for 8 years), external validation (the AUC ranged from 0.874 to 0.976 for 3 years, 0.847 to 0.921 for 5 years, and 0.802 to 0.886 for 8 years), and multi-resource testing (the AUC ranged from 0.752 to 0.869 for 4 years). With respect to the prediction of high myopia development by 18 years of age, as a surrogate of high myopia in adulthood, the algorithm provided clinically acceptable accuracy over 3 years (the AUC ranged from 0.940 to 0.985), 5 years (the AUC ranged from 0.856 to 0.901), and even 8 years (the AUC ranged from 0.801 to 0.837). Meanwhile, our algorithm achieved clinically acceptable prediction of the actual refraction values at future time points, which is supported by the regressive performance and calibration curves. Although the algorithm achiev...

Summary In this work, a fuzzy adaptive two‐bits‐triggered control is investigated for the nonlinear uncertain systems with input saturation and output constraint. The considered systems are more widespread. Without sufficient transmission resources, how to resolve the constraint issues while guarantee the control performance is difficult and challenging. Then, hyperbolic tangent function and barrier Lyapunov function are integrated with the designed auxiliary system to solve input saturation and output constraint. Meanwhile, faced with the transmission resources limitation, this work both considers the triggering condition and the control signal transmission bits. A two‐bits‐triggered control is proposed to economize the transmission resources. Furthermore, improved fuzzy logic systems are established to further promote the control performance. It combines with the time‐varying approximation error for processing. The boundedness of all the system signals can be proved. Simulation results illustrate the validity of the proposed approach.

This study describes a general chemoselective Suzuki–Miyaura coupling of polyhalogenated aryl triflates with the reactivity order of C–Cl > C–OTf using a Pd/L33 catalyst. The methine hydrogen and the steric hindrance offered by the alkyl bottom ring of L33 were found to be key factors in reactivity and chemoselectivity. With the Pd/L33 catalyst, a wide range of polyhalogenated (hetero)­aryl triflates, which were independent of the substrates and of the relative positioning of the competing reaction sites, coupled well with (hetero)­aryl, alkenyl, and alkylboronic acids to obtain the corresponding products with good chemoselectivity and yields. The chemoselective reaction could easily be scaled up to the gram scale, and the use of parts per million levels of Pd catalyst (as low as 10 ppm Pd) was achieved.

Palladium-catalyzed chemoselective direct α-arylation of carbonyl compounds with chloroaryl triflates in the Ar–Cl bond is reported. The effects of –PR2 and C2-alkyl groups of the ligands are investigated using experimental and computational methods.

A new synthetic approach to dihydrofuran derivatives via the annulation reaction of β-naphthols and 4-hydroxycoumarins with vinylsulfonium salts has been developed. A variety of dihydrofuran derivatives were prepared in moderate to good yields under mild conditions. The products could be readily transformed to the corresponding furans via the dehydrogenation with DDQ.

This study reports the palladium-catalyzed chemoselective borylation of (poly)halogenated aryl triflates with a reactivity order of CÀ Cl > CÀ OTf. A catalyst system comprising Pd(OAc) 2 and SelectPhos (L1) enables a reaction with high reactivity and chemoselectivity. The consecutively chemoselective borylation reaction followed by the chemoselective intermolecular Suzuki-Miyaura reaction can be performed using a one-pot two-step approach to synthesize unsymmetrical biaryl compounds containing the triflate moiety. The reaction can be scaled up to the gram scale without diminishing the yield and chemoselectivity.

KOt-Bu/DMF promoted intramolecular addition of diarylmethanols to imines was developed. A series of 2,3-disubstituted indoles was obtained in good yields. A reaction mechanism of radical cyclization and subsequent dehydration is proposed.

This paper presents the first general examples of selective palladium-catalyzed mono-α-arylation of aryl and heteroaryl ketones with aryl phosphates. The catalyst system, consisting of [Pd(2-butenyl)Cl] 2 and MorDalPhos, exhibited high catalytic reactivity toward this reaction. A wide range of aryl phosphates were efficiently coupled with aryl and heteroaryl ketones with good selectivity. Excellent-to-good product yields were afforded. The gram-scale reaction was conducted smoothly. Reductive elimination or transmetalation might be a rate-determining step in this reaction.