[Translocation, Accumulation, and Comprehensive Risk Assessment of Heavy Metals in Soil-Crop Systems in an Old Industrial City, Shizuishan, Ningxia, Northwest China].

In order to explore the environmental geochemistry characteristics of heavy metals (HMs) in soil-crop systems in an old industrial city, the concentration and fraction of HMs in the paddy, wheat, and maize root soil and their seeds were detected and analyzed. Subsequently, statistical methods, risk assessment coding (RAC), the bio-enrichment coefficient factor (BCF), influence index of comprehensive quality (IICQ), and ArcGIS spatial interpolation were used to conduct the translocation, accumulation, and comprehensive risk assessment of HMs in soil-crop systems. The results showed that the average concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in root soil were ranked respectively as follows:12.56, 0.19, 63.48, 23.52, 0.038, 28.86, 21.68, and 69.47 mg·kg-1. HMs in root soil were accumulated to some extent in comparison with the soil background value in Ningxia, especially Cd and Hg, but did not exceed the soil environmental pollution screening value (GB 14618-2018). The average concentrations of the eight aforementioned elements in supporting crop seeds were 0.0149, 0.0112, 0.075, 6.7, 0.0015, 0.67, 0.0427, and 20.48 mg·kg-1 in turn. The over-limit ratio of As, Pb, and Cr in crop seeds was 4%, 3%, and 1%, respectively, relative to the national food safety standards (GB 2762-2017), whereas the other five elements were within the allowable range. In comparison to those in paddy and wheat, HMs hardly tended to translocate to maize seeds from root soil. According to the results of IICQ in soil-crop systems, the cultivated soil was in the state of slight sub-contamination regionally, and only 10% of sampling points showed slight (sub-)contamination-submoderate contamination, where we could replant maize to reduce HMs contamination risk.

Selective recognition and fast enrichment of anthocyanins by dummy molecularly imprinted magnetic nanoparticles.

In this work, a novel synthetic strategy for separation media which quickly specific recognize anthocyanins was developed by dummy molecular imprinting technology and magnetic separation technology. Rutin, similar to cyanidin-3-O-rutinoside structure, was selected as a virtual template. The appropriate molecular imprinting system was selected by NIP library screening method, 4-vinyl pyridine and acetonitrile as functional monomer and solvent respectively. The molecularly imprinted layer was formed on the surface of the magnetic carrier to prepare dummy magnetic molecularly imprinted polymers. The microstructures of prepared composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). Adsorption kinetics, isothermal adsorption curves and selective specificity were investigated to further reveal the specific recognition mechanism of the adsorbents on anthocyanins. The dummy molecularly imprinted polymers showed a short kinetic equilibrium time, high selectivity (comparing with quercetin and naringin), and satisfying adsorption capacity for anthocyanins. The binding capacity and the imprinting factor of dummy molecularly imprinted polymers can reach 15.69 mg g-1 and 2.05, respectively. In addition, the purity of cyanidin-3-O-rutinoside in the crude extract from Lonicera caerulea increased to 89% after the adsorption of dummy magnetic molecular imprinted polymers. Many favorable capabilities of the prepared molecularly imprinted polymers also provided the basis for further application for separation and purification of anthocyanins in the future.

Determination of free amino acids and 18 elements in freeze-dried strawberry and blueberry fruit using an Amino Acid Analyzer and ICP-MS with micro-wave digestion.

The objective of this study was to investigate the level of 18 trace elements of two freeze-dried samples from the Blueberry (Vaccinium corymbosum) and the Strawberry (Fragaria × Ananassa). The total free amino acid composition in the blueberry and strawberry was determined by an Amino Acid Analyzer. Eleven free amino acids were found in both berries. The trace elements in each dried fruit sample were determined by ICP-MS with microwave digestion. The linearity range of the standard curves was 0-1250.0 µg L(-1) (Mg, P, K, Ca),while in all cases, except for B, Na, Al, Cr, Mn, Fe, Ni, Cu, Zn, Se, Cd, Pb, Ge and As, which was 125.0 µg mL(-1), all related coefficients were above 0.9999; recovery was in the range of 79.0-106.8%. Minor concentrations of nutritional elements were found in each freeze-dried berry. In sum, the toxic trace element analysis found the content of toxic trace elements in each freeze-dried berry sample was safe for human consumption and that the overall quality of the blueberry surpassed that of the strawberry. The results certify that the two freeze-dried berries have potential for human consumption in value-added products and have a certain theoretical and practical significance.

Pu-erh tea hot-water extract activates Akt and induces insulin-independent glucose transport in rat skeletal muscle.

Skeletal muscle is a major organ that is important for whole-body glucose metabolism. We found that when isolated rat epitrochlearis muscle was incubated with a Pu-erh tea hot-water extract (PTE) for 30 min, the rate of 3-O-methyl-D-glucose (3MG) transport increased in the absence of insulin. This activation was associated with an increase in Ser(473) phosphorylation of Akt, a signaling intermediary leading to insulin-dependent glucose transport, but not Tyr(458) phosphorylation of phosphoinositide 3-kinase p85, an upstream molecule of Akt. PTE-stimulated 3MG transport was also not accompanied by Thr(172) phosphorylation of the catalytic α-subunit of 5'-AMP-activated protein kinase (AMPK). Gallic acid, a water-soluble ingredient in Pu-erh tea, stimulated Akt phosphorylation, but not AMPK phosphorylation. These results suggest that Pu-erh tea potentially promotes skeletal muscle glucose transport at least in part by activating Akt.