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The Hexi Corridor is the main commodity grain base in northwest China and plays a special role in ensuring food security in northwest China. However, the multiple pollution transport pathways of PAHs and complex and co-existing potential pollution sources around the study areas require a combination of pollution status, source identification, and risk assessment to explore pollution distribution and potential risks. In this study, the total PAHs concentration (∑18PAHs) in soils ranged from 69.6 to 1300 ng/g. Spatially, the higher content of PAHs was detected in the Jinchang, followed by Jiayuguan, Jiuquan, Wuwei, and Zhangye, indicating a remarkable influence of different industrial activities. Although high-molecular-weight PAHs were predominated, the compositions of PAHs in most of the soil samples were varied. The isomer ratios of PAHs and principal component analysis were also revealed the PAHs probably originate from the sources different significantly. The total health risk values indicated a low health risk.

The Hexi Corridor is the main commodity grain base in northwest China and plays a special role in ensuring food security in northwest China. However, the multiple pollution transport pathways of PAHs and complex and co-existing potential pollution sources around the study areas require a combination of pollution status, source identification, and risk assessment to explore pollution distribution and potential risks. In this study, the total PAHs concentration (∑

The presence of antibiotic in aquatic environments has become a topic of great concern with respect to both environment and global public health. However, to date, only a few studies have been carried out on the sorption behavior of antibiotics in aquatic environments. In this study, batch equilibrium experiments were conducted to explore the sorption/desorption behavior of Chlortetracycline (CTC) on the sediments in the Lanzhou section of the Yellow River. The results showed multilayer chemisorption on heterogeneous surfaces dominated by hydrophobic distribution and an obvious hysteresis phenomenon was observed. In addition, the sorption was found to be influenced by factors such as a continuous increase in the temperature, reduction in the initial concentration of CTC, and the increasing particle size of the sediments. The pH was found to affect the dissociation degree of CTC, and the sorptive amount was found to decrease with the increase in the pH value. The presence of other ions which with high valence state and concentration presenting an obvious inhibitory effect in the sorption process. Additionally, the large sorptive amount of antibiotics in the sediments due to the high Cation exchange capacity (CEC), organic matter, and clay particles indicated the influence of the physicochemical properties of sediments on the sorption behavior of antibiotics. This study preliminarily grasps the trend of CTC sorption/desorption on sediments, which is helpful in understanding the fate of CTC and assessing its ecological risks in the upper reaches of the Yellow River.

Adding livestock manure to soil to improve soil quality is a common agricultural practice. However, information on the effect of manure soil amendments on the sorption of veterinary antibiotics is scarce. Batch equilibrium experiments were utilized to investigate the effects of livestock manures on the sorption of chlortetracycline (CTC) onto sierozem. Kinetic sorption results showed that sorption equilibrium for CTC was reached within 2 h, and the presence of livestock manures lengthened the time to equilibrium attainment and promoted the sorption capacity of CTC onto sierozem. A good fit of the sorption kinetic data was achieved with a pseudo-second-order model with or without the presence of animal manure. Both boundary layer control and intraparticle diffusion were related to the sorption kinetic process. The CTC sorption isotherm of sierozem fit well with both Freundlich isothermal and linear models. The sorption of CTC onto sierozem exhibited strong pH dependence and was strongly governed by the ability of each substance to ionize as a function of pH. A decrease in CTC sorption was observed with increasing ionic strength as electrolyte cations competed with the positively charged CTC species and complexes for sorption sites. CTC sorption capacity declined when the solution contained Ca2+ compared to Na+ and Mg2+ solutions at similar ionic strength. The sorption of CTC by sierozem affected by livestock manures exhibited strong dependence on the amendment amount. The results suggest that manure application may change the sorption behavior and mechanism of CTC on loess soil. These findings contribute to understanding the fate and risk of veterinary antibiotics in loess soil affected by manure application.

Background In physiological and pathological conditions activated protein kinace C (PKC) has been observed in the erythrocytes. Externalization of ankyrin followed by Arg–Gly–Asp (RGD)/integrin recognition also triggers erythrophagocytosis. In the present study, to test whether activated PKC is associated with ankyrin exposure in erythrophagocytosis. Methods Phorbol 12-myristate-13-acetate (PMA)-induced PKC activation and ankyrin phosphorylation were tested, and under different treatment conditions the subpopulation of erythrocytes with ankyrin exposure and the levels of intracellular calcium were analyzed by flow cytometry. Results Results showed that treatment of erythrocytes with PMA in a calcium-containing buffer led to ankyrin exposure. In the absence of extracellular calcium, no ankyrin exposure was observed. PKC inhibition with calphostin C, a blocker of the PMA binding site, completely prevented the calcium entry, protein phosphorylation and ankyrin exposure. PKC inhibition with chelerythrine chloride, an inhibitor of the active site, diminished the level of ankyrin-exposing cells and ankyrin phosphorylation; however it even led to a higher percentage of cells with increased levels of calcium than with PMA treatment alone. Although PKC was activated and ankyrin phosphorylation occurred, no ankyrin exposure was observed in the absence of extracellular calcium. Conclusion Analyses of results suggested that PMA induces calcium influx into the erythrocytes, leading to the activation of calcium-dependent enzymes and the phosphorylation of membrane proteins, ultimately inducing ankyrin exposure and erythrophagocytosis. This study may provide insights into the molecular mechanisms of removing aged or diseased erythrocytes.

This paper was to explore the effect of blood oxygen saturation (SO2) on oxidative damages of erythrocytes under the condition of oxidative stress. Keeping SO2 of cultured erythrocytes in vitro at the states of 0.3, 0.5, 0.7, 0.9 and 0.98, respectively, we induced oxidative stress by tert-buthylhydroperoxide (BHP, 0.15 mmol/L of final concentration). After incubation, antioxidant capacity was assessed by measuring content of reduced glutathin hormone (GSH) in erythrocytes. Methemoglobin (MetHb) content, lipid peroxidation (thiobarbituric acid-reactive substances, TBARS) and denatured globin-chains on the plasma membrane were measured to assess the extent of oxidative damages. The results showed that in the presence of BHP, GSH contents increased from 0.3 to 0.98 groups; MetHb, TBARS and globin-chains levels all dropped with the rise of SO2. In conclusion, antioxidant capacity and oxidative damages of erythrocytes are closely related to SO2, declined SO2 could promote oxidative damages of erythrocytes.