Nano-TiO2 aggravates the adverse effect of pentachlorophenol on antioxidant and immune response in anti-predatory mussels.

Nano-TiO2 can act as a vector to organic compounds, such as pentachlorophenol (PCP) posing a potential threat to the marine ecosystems. Studies showed that nano pollutant toxicity can be modulated by abiotic factors, but little is known about the potential influence of biotic stressors (such as predators) on the physiological responses to pollutants in marine organisms. We explored the effects of n-TiO2 and PCP on the mussel Mytilus coruscus in the presence of its natural predator, the swimming crab Portunus trituberculatus. Exposure to n-TiO2, PCP, and predation risk showed interactive effects on antioxidant and immune parameters of the mussels. Elevated activities of catalase (CAT), glutathione peroxidase (GPX), acid phosphatase (ACP) and alkaline phosphatase (AKP), suppressed activity of superoxide dismutase (SOD), lower levels of glutathione (GSH) and increased malondialdehyde (MDA) levels indicated dysregulation of the antioxidant system and immune stress induced by single PCP or n-TiO2 exposure. Integrated biomarker (IBR) response values showed the effect of PCP was concentration dependent. Of the two used n-TiO2 sizes (25 and 100 nm), larger particles induced higher antioxidant and immune disturbances indicating higher toxicity possibly due to higher bioavailability. Compared to single PCP exposure, the combination of n-TiO2 and PCP enhanced the imbalance of SOD/CAT and GSH/GPX and led to elevated oxidative lesions and activation of immune-related enzymes. Overall, the combined impacts of pollutants and biotic stress exhibited a greater magnitude of adverse effects on antioxidant defense and immune parameters in mussels. The toxicological effects of PCP were exacerbated in the presence of n-TiO2, and the deleterious impact of these stressors was further amplified under predator-induced risk after prolonged (28 days) exposure. However, the underlying physiological regulatory mechanisms governing the interplay of these stressors and predatory cues on mussels remain elusive, warranting further investigation.

Keggin-type polyoxometalate-based crown ether complex for lithium-sulfur batteries.

A novel supramolecular complex Li3Cl[(HPW12O40)(H24C12O6)3(CH3CN)2] {CR-PW12} was confirmed first to apply as a sulfur host in lithium-sulfur batteries. The {CR-PW12}@S cathode exhibits a reversible capacity of 1120 mA h g-1 at 1.0 C and excellent cycle stability.

Multishelled Nickel-Cobalt Oxide Hollow Microspheres with Optimized Compositions and Shell Porosity for High-Performance Pseudocapacitors.

Nickel-cobalt oxides/hydroxides have been considered as promising electrode materials for a high-performance supercapacitor. However, their energy density and cycle stability are still very poor at high current density. Moreover, there are few reports on the fabrication of mixed transition-metal oxides with multishelled hollow structures. Here, we demonstrate a new and flexible strategy for the preparation of hollow Ni-Co-O microspheres with optimized Ni/Co ratios, controlled shell porosity, shell numbers, and shell thickness. Owing to its high effective electrode area and electron transfer number (n(3/2) A), mesoporous shells, and fast electron/ion transfer, the triple-shelled Ni-Co1.5-O electrode exhibits an ultrahigh capacitance (1884 F/g at 3A/g) and rate capability (77.7%, 3-30A/g). Moreover, the assembled sandwiched Ni-Co1.5-O//RGO@Fe3O4 asymmetric supercapacitor (ACS) retains 79.4% of its initial capacitance after 10 000 cycles and shows a high energy density of 41.5 W h kg(-1) at 505 W kg(-1). Importantly, the ACS device delivers a high energy density of 22.8 W h kg(-1) even at 7600 W kg(-1), which is superior to most of the reported asymmetric capacitors. This study has provided a facile and general approach to fabricate Ni/Co mixed transition-metal oxides for energy storage.