The Impact of Heterogeneity on Single-Cell Sequencing

The importance of diversity and cellular specialization is clear for many reasons, from population-level diversification, to improved resiliency to unforeseen stresses, to unique functions within metazoan organisms during development and differentiation. However, the level of cellular heterogeneity is just now becoming clear through the integration of genome-wide analyses and more cost effective Next Generation Sequencing (NGS). With easy access to single-cell NGS (scNGS), new opportunities exist to examine different levels of gene expression and somatic mutational heterogeneity, but these assays can generate yottabyte scale data. Here, we model the importance of heterogeneity for large-scale analysis of scNGS data, with a focus on the utilization in oncology and other diseases, providing a guide to aid in sample size and experimental design

Polyacrylate Backbone Promotes Photoinduced Reversible Solid-To-Liquid Transitions of Azobenzene-Containing Polymers

The development of polymers with efficient photoinduced reversible solid-to-liquid transitions is desirable for the design of healable materials, reconfigurable devices, and switchable adhesives. Herein, we demonstrate that an azobenzene-containing polyacrylate P-H exhibits more efficient photoinduced reversible solid-to-liquid transitions than its polymethacrylate analogue P-Me. The side chain of P-H or P-Me contains a hexamethylene spacer, a photoresponsive azobenzene group, and an n-decyl tail. Both P-H and P-Me show reversible cis–trans photoisomerization. Solid transP-H and P-Me change to liquid cis ones via UV-light-induced trans-to-cis isomerization; liquid cisP-H and P-Me revert to solid trans ones via visible-light-induced cis-to-trans back isomerization. Differential scanning calorimetry and rheology measurements revealed that photoinduced reversible solid-to-liquid transitions occur because P-H and P-Me have photoswitchable glass transition temperatures. Although P-Me exhibits a slightly faster rate for trans-to-cis photoisomerization than P-H due to fewer aggregates in solid state, cisP-H flows 20 times faster than cisP-Me because P-H has a more flexible polymer backbone. The low viscosity of cisP-H makes photoinduced solid-to-liquid transition efficient and enables the design of rapidly healable coatings. Our study shows that the design of a flexible backbone is a new strategy to develop rapidly healable polymers with more efficient photoinduced solid-to-liquid transitions

Plastic waste discharge to the global ocean constrained by seawater observations

Marine plastic pollution poses a potential threat to the ecosystem, but the sources and their magnitudes remain largely unclear. Existing bottom-up emission inventories vary among studies for two to three orders of magnitudes (OMs). Here, we adopt a top-down approach that uses observed dataset of sea surface plastic concentrations and an ensemble of ocean transport models to reduce the uncertainty of global plastic discharge. The optimal estimation of plastic emissions in this study varies about 1.5 OMs: 0.70 (0.13-3.8 as a 95% confidence interval) million metric tons yr-1 at the present day. We find that the variability of surface plastic abundance caused by different emission inventories is higher than that caused by model parameters. We suggest that more accurate emission inventories, more data for the abundance in the seawater and other compartments, and more accurate model parameters are required to further reduce the uncertainty of our estimate

Plastic waste discharge to the global ocean constrained by seawater observations

Abstract Marine plastic pollution poses a potential threat to the ecosystem, but the sources and their magnitudes remain largely unclear. Existing bottom-up emission inventories vary among studies for two to three orders of magnitudes (OMs). Here, we adopt a top-down approach that uses observed dataset of sea surface plastic concentrations and an ensemble of ocean transport models to reduce the uncertainty of global plastic discharge. The optimal estimation of plastic emissions in this study varies about 1.5 OMs: 0.70 (0.13–3.8 as a 95% confidence interval) million metric tons yr−1 at the present day. We find that the variability of surface plastic abundance caused by different emission inventories is higher than that caused by model parameters. We suggest that more accurate emission inventories, more data for the abundance in the seawater and other compartments, and more accurate model parameters are required to further reduce the uncertainty of our estimate