Simultaneous degradation of binary fluoroquinolone antibiotics by B and N in-situ self-doped guar gum hydrogel.

Using guar gum (GG) as the raw material and borax (B) as the cross-linker, zeolitic imidazolate framework-8 (ZIF-8) was in-situ loaded into the 3D network of GG hydrogel, forming a highly efficient catalytic material GG-B-ZIF-8 combined with a subsequent low-temperature calcination process. In GG-B-ZIF-8 activated peroxymonosulfate (PMS) system, binary norfloxacin (NOR) and ciprofloxacin (CIP) could be removed simultaneously, with the degradation efficiency of >99.9% within 1 h. This system was adaptable to a wide pH range of 3.0-9.0, and was also highly resistant to 5-20 mM Cl- and 10-40 mg/L humic acid. The degradation process was dominated by free radical O2•-, non-radical 1O2 and electron transfer, with eleven degradation products identified for NOR and nine for CIP via eight possible degradation pathways. Finally, the potential eco-toxicity of NOR, CIP and degradation intermediates was evaluated using the ECOSAR method.

A novel transformation pathway of p-arsanilic acid in water by colloid ferric hydroxide under UVA light.

Iron species that occur in natural surface water could affect the photochemical behavior of pollutants. Complexation between iron species and polycarboxylate or heavy metals has been widely reported, where the ligands could be oxidized via ligand-to-metal charge transfer (LMCT) by light inducement. Such complexation and photochemical reactions might also occur for low valance metal-containing organic compounds, which is worthy of investigation. This work studied the phototransformation of p-arsanilic acid (ASA), an organic arsenic compound that is widely used as a feed additive in the poultry industry, by colloidal ferric hydroxide (CFH) using black light lamps (λ = 365 nm) as the light source. The results revealed the contribution to ASA transformation at circumneutral conditions by CFH through an LMCT process, which is the same as that for As(III). The complexation between ASA and CFH was investigated using UV-vis spectroscopy. The estimated equilibrium constant for the CFH-ASA complex was log Kf271 = 4.22. The analysis of the photoproducts found the generation of both inorganic and organic arsenic. Our findings confirmed the similarities in the photochemical mechanisms of ASA and As(III) in the presence of CFH. The results help in further understanding the fate of organoarsenicals in the surface water environment.

The antidepressant effects of ɑ-tocopherol are related to activation of autophagy via the AMPK/mTOR pathway.

The purpose of the present study was to investigate whether ɑ-tocopherol exhibited neuro-protective effects in chronic unpredictable mild stress (CUMS) mice through the regulation of autophagy. Deficits in behavioural tests, including a sucrose preference test, open field test, forced swim test, and tail suspension test, were ameliorated following ɑ-tocopherol administration. To study the potential mechanism, western blots were performed on both prefrontal cortex and hippocampus samples. Similar to the degree of autophagy, the activities of adenosine monophosphate-activated protein kinase (AMPK) and Unci-51 like autophagy activating kinase-1 (ULK1) were decreased after CUMS stimulation. In addition, we also found increased activity of the mammalian target of rapamycin (mTOR), which was significantly affected following administration of ɑ-tocopherol, as well as its three downstream pathways. Taken together, our study found that ɑ-tocopherol might potentially promote autophagy to induce anti-depressive responses in CUMS mice though the AMPK/mTOR pathway.