New insights into the reverse of chromium-induced reprotoxicity of pregnant mice by melatonin.

Hexavalent chromium Cr(VI) is a well-known environmental toxic metal that causes reprotoxicity in pregnant females. There are currently no appropriate interventions or treatments for Cr(VI) exposure during pregnancy. Herein, the protective effect of melatonin (MLT) against Cr(VI)-induced reprotoxicity is investigated by administrating MLT to pregnant mice exposed to Cr(VI). The results indicate that MLT effectively alleviates Cr(VI)-induced adverse pregnancy outcomes, restoring the decreased fetal weight and increased fetal resorption and malformation caused by Cr(VI) exposure to normal levels. MLT reduces the negative effects of Cr(VI) on follicular atresia and the development of primordial follicle in the maternal ovarian, thereby mitigating the decline in the reserve of primordial follicles. MLT alleviates Cr(VI)-induced oxidative stress, hence reducing the excessive accumulation of malondialdehyde in the maternal ovary. MLT inhibits Cr(VI)-induced apoptosis of ovarian granulosa cells and the expression of cleaved caspase-3 in the ovary. MLT reduces the increase in serum follicle-stimulating hormone caused by Cr(VI) exposure, while elevating anti-Mullerian hormone levels. We demonstrate that MLT reverses Cr(VI)-induced reprotoxicity in pregnant mice, opening up a new avenue for treating reproductive defects caused by environmental stress.

Boron regulates catalytic sites of biochar to enhance the formation of surface-confined complex for improved peroxydisulfate activation.

Biochar has been developed to activate persulfate for wastewater treatment due to its carbon essence, easily-available and low-cost. Efficiently active sites and interfacial electron transfer are highly desired for peroxydisulfate (PDS) activation. In this study, boronic ester structure and defect degree of boron-doped biochar are confirmed as activate sites to improve PDS activation. The performance of pollutants degradation is proven to have structure-activity relationships with both activate sites. Moreover, boron-doped biochar exhibits higher stability and oxidation potential by forming the surface-confined complex, promoting electron transfer from pollutants to complex. The optimized boron-doped biochar has the advantages of adapting to a broad pH range (2.9-10.0), strong resistance to Cl- and organic matters, a low activation energy of 11.22 kJ mol-1, and achieving the decomposition of practical dyeing wastewater. Our work provides a promising approach to regulating the interfacial catalytic sites of biochar by doping heteroatom for PDS activation in practical wastewater treatment.