Efficient removal of paracetamol using LaCu1-xMxO3 (M=Mn, Ti) perovskites as heterogeneous Fenton-like catalysts

A series of perovskite-like oxides LaCu1-xMxO3 (M=Mn, Ti; 0.0 ⩽ x ⩽ 0.8) was prepared by amorphous citrate decomposition and characterized by XRD, ICP-OES and XPS techniques. The catalysts were tested in the Fenton-like degradation of paracetamol with H2O2, under mild reaction conditions, 25 °C and nearly neutral pH. Values of decomposition of paracetamol between 80 and 97% at 300 min were achieved for most of samples. The presence of the Cu2+/Cu+ pair at the surface of the catalysts is necessary to carry out the reaction and the catalysts containing higher amount of copper at the surface, resulted to be more active. The leaching of metals was less than 1%, which discards the contribution of the homogenous Fenton-like reaction and remarks the high stability of the metals into the mixed oxide network. The catalytic activity of LaCu0.8Mn0.2O3 was maintained after three cycles of reaction, which proves the stability and reusability of the catalyst.

Altered oscillatory dynamics of CA1 parvalbumin-basket cells during theta-gamma rhythmopathies of temporal lobe epilepsy

Recent reports in human demonstrate a role of theta– gamma coupling in memory for spatial episodes and a lack of coupling in people experiencing temporal lobe epilepsy, but the mechanisms are unknown. Using multisite silicon probe recordings of epileptic rats engaged in episodic-like object recognition tasks, we sought to evaluate the role of theta– gamma coupling in the absence of epileptiform activities. Our data reveal a specific association between theta– gamma (30 – 60 Hz) coupling at the proximal stratum radiatum of CA1 and spatial memory deficits. We targeted the microcircuit mechanisms with a novel approach to identify putative interneuronal types in tetrode recordings (parvalbumin basket cells in particular) and validated classification criteria in the epileptic context with neurochemical identification of intracellularly recorded cells. In epileptic rats, putative parvalbumin basket cells fired poorly modulated at the falling theta phase, consistent with weaker inputs from Schaffer collaterals and attenuated gamma oscillations, as evaluated by theta-phase decomposition of current–source density signals. We propose that theta– gamma interneuronal rhythmopathies of the temporal lobe are intimately related to episodic memory dysfunction in this condition.