RESUMO
This study aims to investigate the performance of a low-strength magnetic field in membrane bioreactors (MBRs) for membrane fouling mitigation and its effects on sludge characteristics and microbial community. The continuous operation of MBR with magnetic powder (MP-MBR) is denoted as the control-MBR, and a magnetic field is added to the MP-MBR to form the magnetic-MBR (M-MBR). The comparison between MP-MBR and M-MBR was conducted to treat synthetic wastewater. The results showed that the application of a low-strength magnetic field not only decreased the zeta potential and increased the particle size, but also improved the dehydrogenase activity and stimulated microbes to produce fewer SMPs, which markedly contributed to the improved filtration performance of MBRs. The variations in the microbial communities from the two MBRs at genus levels confirmed that the addition of a low-strength magnetic field significantly affected the microbial community and composition, further altered the microbial metabolites, and consequently affected the membrane fouling evolution.
RESUMO
Objective To investigate the effect of electroacupuncture at point Fenglong(ST40) on the expressions of macrophage surface antigen CD11b and intercellular adhesion molecule-1 (ICAM-1) in hyperlipidemia rats. Method Forty healthy SD rats were randomly allocated to normal control, high fat diet, high fat+common diet, high fat diet and treatment, and high fat+common diet and treatment groups. After 28 days of treatment with electroacupuncture at point Fenglong, blood lipid levels, namely, total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) contents were measured in every group of rats. The expressions of peritoneal macrophage surface antigen CD11b and ICAM-1 were examined using flow cytometry (FCM) in every group of rats. Result Plasma TC and LDL-C increased significantly in the high fat diet group of rats compared with the normal control group (P0.05). The expression rates of macrophage CD11b and ICAM-1 increased significantly in the high fat diet group of rats compared with the normal group (P<0.01). In the high fat+common diet group of rats, the expression rates of macrophage CD11b and ICAM-1 decreased significantly in comparison with the high fat diet group (P<0.05) but increased significantly in comparison with the normal group (P<0.01). The expression rates of CD11b and ICAM-1 decreased significantly in the high fat diet and treatment group compared with the high fat diet group (P<0.01) and decreased significantly in the high fat+common diet and treatment group compared with the high fat+common diet group (P<0.01) and the high fat diet and treatment group (P<0.01). Correlation analysis showed that CD11b and ICAM-1 levels had a significantly positive correlation (r=0.947, P<0.01). Conclusion Electroacupuncture at point Fenglong can significantly down-regulate blood fat TC and LDL-C levels and the expressions of macrophage CD11b and ICAM-1 in hyperlipidemia rats. It has a certain therapeutic effect on hyperlipidemia.
