Size distribution and diffuse pollution impacts of PAHs in street dust in urban streams in the Yangtze River Delta

Particles of dust washed off streets by stormwater are an important pathway of polyaromatic hydrocarbons (PAHs) into urban streams. This article presented a comprehensive assessment of the size distribution of PAHs in street dust particles, the potential risks of the particles in urban streams, and the sources and sinks of PAHs in the stream network. This assessment was based on measurements of 16 PAHs from the USEPA priority list in street dust particles and river sediments in Xincheng, China. The content of total PAHs ranged from 1629 to 8986 μg/kg in street dust particles, where smaller particles have a higher concentrations. Approximately 55% of the total PAHs were associated with particles less than 250 μm which accounted for 40% of the total mass of street dust. The PAH quantities increased from 2.41 to 46.86 μg/m2 in the sequence of new residential, rising through main roads, old town residential, commercial and industrial areas. The sediments in stream reaches in town were found to be sinks for street dust particle PAHs. The research findings suggested that particle size, land use and the hydrological conditions in the stream network were the factors which most influenced the total loads of PAH in the receiving water bodies.<br/

An ex vivo culture model of kidney podocyte injury reveals mechanosensitive, synaptopodin-templating, sarcomere-like structures

Chronic kidney diseases are widespread and incurable. The biophysical mechanisms underlying them are unclear, in part because material systems for reconstituting the microenvironment of relevant kidney cells are limited. A critical question is how kidney podocytes (glomerular epithelial cells) regenerate foot processes of the filtration apparatus following injury. Recently identified sarcomere-like structures (SLSs) with periodically spaced myosin IIA and synaptopodin appear in injured podocytes in vivo. We hypothesized that SLSs template synaptopodin in the initial stages of recovery in response to microenvironmental stimuli and tested this hypothesis by developing an ex vivo culture system that allows control of the podocyte microenvironment. Results supported our hypothesis. SLSs in podocytes that migrated from isolated kidney glomeruli presented periodic synaptopodin-positive clusters that nucleated peripheral, foot process-like extensions. SLSs were mechanoresponsive to actomyosin inhibitors and substrate stiffness. Results suggest SLSs as mechanobiological mediators of podocyte recovery and as potential targets for therapeutic intervention

Biomimetic lubricant-infused titania nanoparticle surfaces via layer-by-layer deposition to control biofouling

Lubricant-infused surfaces have attracted a lot of attention in antifouling applications. Previously, lubricant-infused surfaces fabricated by a layer-by-layer process involved two or more polyelectrolytes and needed post-treatments to generate pores. Here, the paper proposes a layer-by-layer sol-gel process to prepare a lubricant-infused surface. This process only involves a single material and without any post-treatment. The nanostructured titania layers were layer-by-layer assembled onto 316L stainless steel substrates by immersing the substrates into a titanium (IV) butoxide ethanol solution. The titania layers were subsequently surface-functionalized by fluorinated silanes and infiltrated with fluorinated lubricant to form lubricant-infused nanoparticle surfaces. The physicochemical properties of the lubricant-infused nanoparticle surfaces dominated the antifouling performance. These results give some insight into the construction of lubricant-infused nanoparticle surfaces with desirable liquid repellency and antifouling properties via a layer-by-layer sol-gel process