Toxicity of polystyrene nanoplastics to human embryonic kidney cells and human normal liver cells: Effect of particle size and Pb2+ enrichment.

Nanoplastics pollution in drinking water has aroused wide concern, but their effects on human health are still poorly understood. Herein we explore the responses of human embryonic kidney 293T cells and human normal liver LO2 cells to polystyrene nanoplastics, mainly focusing on the effects of particle sizes and enrichment of Pb2+. When the exposed particle size is higher than 100 nm, there is no obvious death for these two different cell lines. As the particle size decreases from 100 nm, cell mortality goes up. Although the internalization of polystyrene nanoplastics in LO2 cells is at least 5 times higher than that in 293T cells, the mortality of LO2 cells is lower than that of 293T cells, illustrating that LO2 cells are more resistant to polystyrene nanoplastics than 293T cells. Additionally, the Pb2+ enrichment on polystyrene nanoplastics in water can further enhance their toxicity, which should be taken seriously. The cytotoxicity of polystyrene nanoplastics to cell lines works through a molecular mechanism involving oxidative stress-induced damage of mitochondria and cell membranes, resulting in a decrease in ATP production and an increase in membrane permeability. Referenced to nanoplastics pollution in drinking water, there is no necessary to panic about the adverse effects of plastic itself on human health, but the enrichment of contaminants should get more attention. This work provides a reference for the risk assessment of nanoplastics in drinking water to human health.

Novel Dual-Excitation and Dual-Emission Materials: Eu2+,Pb2+ Co-doped Core-Shell-Structured CaS@CaZnOS Phosphors and Their Application for Highly Efficient Photosynthesis of Plants.

Eu2+,Pb2+-doped core-shell-structured CaS@CaZnOS phosphors were synthesized by a two-step high-temperature solid-phase method. The as-synthesized CaS:Eu2+,Pb2+@CaZnOS:Pb2+ phosphors possess excellent dual-excitation and dual-emission (DE2) luminescent properties, which give rise to red emission peaking at 650 nm under green excitation, derived from the core CaS:Eu2+,Pb2+, and blue emission peaking at 424 nm, originating from the shell CaZnOS:Pb2+, under ultraviolet (UV) excitation. In addition, tunable red/blue emission can be achieved by changing the doping concentration of Pb2+ in the CaZnOS shell. The red/blue dual emission of core-shell DE2 phosphors under excitation of UV and green light significantly matches with the absorption spectrum of chlorophyll (a, b); hence, the as-prepared phosphors are excellent solar spectral conversion (SSC) auxiliaries of plastic films or laminated glass for greenhouses and provide ideas for creating more efficient and practically valuable SSC auxiliaries. The DE2 properties are described, and the energy transfer mechanism from Pb2+ to Eu2+ in the core is proposed and discussed in detail.

Distribution behavior of arsenate into α-calcium sulfate hemihydrate transformed from gypsum in solution.

Transforming gypsum into α-calcium sulfate hemihydrate (α-HH) provides a promising utilization pathway for the abundant amount of chemical gypsum. The transformation follows the route of "dissolution-recrystallization", during which the arsenic pollutant in gypsum is released into the solution, and hence raises the possibility of being distributed into the product of α-HH, a potential harm that has always been neglected. Investigation of the transformation process at neutral pH revealed that the arsenate ions in solution were distributed into α-HH and generated an enrichment of arsenic by 4-6 times. Arsenate ions distributed into α-HH by substitution for lattice sulfate, adsorption on α-HH facets and occupation for surface sulfate sites. While at higher concentrations, calcium arsenate coprecipitated with α-HH or even crystallized independently. Increasing temperature accelerated the phase transformation and restrained arsenate migration into α-HH due to the lag of distribution balance. The pH of solution modulated the dominant arsenate species and decreasing pH weakened arsenate substitution capacity for sulfate in α-HH. This work uncovers arsenate distribution mechanism during the transformation of gypsum into α-HH and provides a feasible method to restrain arsenate distribution into product, which helps to understand arsenate behavior in hydrothermal solution with high concentration of sulfate minerals and provides a guidance for controlling pollutants distribution into product.

[Flavonoid constituents from herbs of Sarcopyramis bodinieri var. delicata].

Phytochemical studies of the the herb Sarcopyramis bodinieri var. delicate (Melastomataceae) have been carried out. The compounds were separated by repeated D101 macroporous adsorption resin column combined with Sephadex LH-20, ODS, and silica gel chromatgrophy. The structures were identified on the basis of extensive spectroscopic data analysis, and by comparison of their spectral data with those reported. Eight flavonoid compounds isolated from the ethyl acetate extract was identified as isorhamnetin (1), quercetin (2), isorhamnetin-3-O-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-glucopyranoside (4), isorhamnetin-3-O-(6"-acetyl)-beta-D-glucopyranoside (5), isorhamnetin-3-O-(2"-acetyl)-beta-D-glucopyranoside (6), quercetin-3-O-(6"-acetyl)-beta-D-glucopyranoside (7), and quercetin- 3-O-(6"-O-E-p-coumaroyl)-beta-D-glucopyranoside (8). All of the compounds were separated from the genus of Sarcopyramis for the first time.