Exploring how socioeconomic status affects neighbourhood environments? : effects on obesity risks : a longitudinal study in Singapore

Research on how socioeconomic status interacts with neighbourhood characteristics to influence disparities in obesity outcomes is currently limited by residential segregation-induced structural confounding, a lack of empirical studies outside the U.S. and other 'Western' contexts, and an over-reliance on cross-sectional analyses. This study addresses these challenges by examining how socioeconomic status modifies the effect of accumulated exposures to obesogenic neighbourhood environments on children and mothers' BMI, drawing from a longitudinal mother-child birth cohort study in Singapore, an Asian city-state with relatively little residential segregation. We find that increased access to park connectors was associated with a decrease in BMI outcomes for mothers with higher socioeconomic status, but an increase for those with lower socioeconomic status. We also find that increased access to bus stops was associated with an increase in BMIz of children with lower socioeconomic status, but with a decrease in BMIz of children with higher socioeconomic status, while increased access to rail stations was associated with a decrease in BMIz of children with lower socioeconomic status only. Our results suggest that urban interventions might have heterogeneous effects by socioeconomic status.Peer reviewe

Exploring how socioeconomic status affects neighbourhood environments’ effects on obesity risks: A longitudinal study in Singapore

10.1016/j.landurbplan.2022.104450Landscape and Urban Planning22610445

Thermally activated delayed fluorescence (TADF) organic molecules for efficient X-ray scintillation and imaging

X-ray detection, which plays an important role in medical and industrial fields, usually relies on inorganic scintillators to con- vert X-rays to visible photons; although several high-quantum-yield fluorescent molecules have been tested as scintillators, they are generally less efficient. High-energy radiation can ionize molecules and create secondary electrons and ions. As a result, a high fraction of triplet states is generated, which act as scintillation loss channels. Here we found that X-ray-induced triplet excitons can be exploited for emission through very rapid, thermally activated up-conversion. We report scintillators based on three thermally activated delayed fluorescence molecules with different emission bands, which showed significantly higher efficiency than conventional anthracene-based scintillators. X-ray imaging with 16.6 line pairs mm−1 resolution was also demonstrated. These results highlight the importance of efficient and prompt harvesting of triplet excitons for efficient X-ray scintillation and radiation detection

From Functional Plasticity of Two Diterpene Synthases (IrTPS2/IrKSL3a) to Enzyme Evolution

Terpenoids are an intriguing class of natural products with diverse structures and biological activities whose complexity stems in large part from terpene synthases (TPSs). These enzymes catalyze carbocationic cascade reactions wherein the groups responsible for quenching the final carbocation are generally not well-known. IrKSL3a and IrTPS2 from Isodon rubescens share 98% sequence homology but use distinct quenching strategies, with IrKSL3a catalyzing direct deprotonation to generate the olefin isopimaradiene while IrTPS2 adds water to yield the hydroxylated nezukol. In this work, we discovered a threonine and serine that hydrogen-bond the water to be added in IrTPS2. Site-directed mutagenesis and multiscale QM/MM simulations of modeled structures further reveal that the binding of this water is blocked by the introduction of a β-methyl-containing side chain in a neighboring residue. From these insights, it was then possible to engineer IrKSL3a to generate nezukol, with other new hydroxylated products also observed. Inspired by these mechanistic insights into the functional plasticity of IrKSL3a and IrTPS2, we explored the plausible evolutionary relationship of these kaurene synthase-like (KSL) TPSs, as well as prospective utilization of these plasticity sites discovered in IrTPS2/IrKSL3a. Such experiments with a variety of more phylogenetically distant KSLs demonstrated that these residues are necessary but not sufficient to efficiently introduce such an addition of water, emphasizing the selective pressure underlying the extended evolutionary process for the production of nezukol by IrTPS2

Identifying COVID-19 cases in outpatient settings

10.1017/S0950268821000704EPIDEMIOLOGY AND INFECTION14