Influence of stacking on the aqueous proton penetration behaviour across two-dimensional graphtetrayne.

Two-dimensional (2D) graphtetrayne (G4) with intrinsic pattern triangular nanopores has been predicted to be an excellent candidate for next-generation proton exchange membranes due to its superior proton conductivity and selectivity. However, it is technically challenging to prepare a large area single-layer intact 2D material. A multi-layer stacked 2D material is a much more suitable choice, and the stacking can effectively shield the undesired defects and tears. In this work, we investigate the aqueous proton penetration behavior across multilayer-stacked two-dimensional G4 using extensive ReaxFF molecular dynamics simulations. We found that the G4 layers prefer a slightly misplaced stacking pattern which would cause only a slight reduction in the pore size. Detailed analyses indicate that the "water wires" across G4 remain continuous and can provide a low-barrier path for proton penetration until the number of stacking layers increases to three. In triple-layer G4, the "water wires" no longer exist and the aqueous phase will be separated by a wide vacuum area, thus significantly impeding the proton penetration behavior. Based on these results, we suggest that when serving as a proton exchange membrane, the number of stacking G4 layers should be fewer than three to achieve satisfactory conductivity. Our work provides guidance for the fabrication of next-generation proton exchange membranes based on nanoporous 2D materials.

Geniposide attenuates epilepsy symptoms in a mouse model through the PI3K/Akt/GSK-3ß signaling pathway.

Previous reports on the pharmacological actions of geniposide have indicated that it has anti-asthmatic, anti-inflammatory and analgesic effects in the liver and gallbladder, and therapeutic effects in neurological, cardiovascular and cerebrovascular diseases. The results of the current study demonstrate that geniposide attenuates epilepsy in a mouse model through the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3ß (GSK-3ß) signaling pathway. A mouse model of epilepsy was induced by maximal electric shock (50 mA, 50 Hz, 1 sec). Epilepsy mice were intragastrically administered with 0, 5, 10 or 20 mg/kg geniposide. Geniposide significantly reduced the incidence and significantly increased the latency of clonic seizures in epileptic mice compared with non-treated epileptic mice (both P<0.01). Geniposide treatment significantly inhibited cyclooxygenase-2 mRNA expression in epilepsy mice (P<0.01). Furthermore, geniposide significantly suppressed the protein expression of activator protein 1, increased the activation of Akt and increased the protein expression of GSK-3ß and PI3K in epilepsy mice (all P<0.01). These results suggest that geniposide attenuates epilepsy in mice through the PI3K/Akt/GSK-3ß signaling pathway.

[An improved characteristic spectral selection method for multicomponent gas quantitative analysis based on Tikhonov regularization].

In the present paper, an improved approach to the TR characteristic spectral selection is presented. For this approach, two ideas of TR1-norm and TR2-norm are used, two constraint items, spectral line distance and minimizing absolute value of coefficient are introduced, and a general formula of ill-posed optimization problem is established. The formula can reduce effectively the errors caused by experienced and experimental method when used in determining the regular matrix and parameter. Finally, the improved approach presented in the paper was used in the analysis of alkane gas mixture, with methane, ethane, propane, n-butane, iso-butane, n-pentane and iso-pentane included. The concentration range is 0.01%-20%. The experimental results show that the predicting error square is only 2.6 x 10(-4), and the coefficient of determination is 0. 959 2, which means that preceding accuracy is high, and that the practicability of TR regularization has been enhanced.