Abstract The purpose of this study was to explore the inhibitory effect of α-methyl-5- hydroxytryptamine (α-methyl-5-HT) on ATP-activated current (IATP) in rat dorsal root ganglion (DRG) neurons. Whole-cell patch clamp experiment was performed on cultured rat DRG neurons. One minute after treatment with α-methyl-5-HT, ATP (10-4 mol/L) activation current in rat DRG neurons was inhibited. However, this inhibitory effect was independent of the current caused by α-methyl-5-HT. The dose-response curve for IATP showed that α-methyl-5-HT significantly shifted it. The Kd values of ATP-activated currents before and after the pre-addition of α-methyl-5-HT were similar (4.23×10-5 mol/L vs. 6.81×10-5 mol/L). Furthermore, cyproheptadine (10-6 mol/L), an antagonist of 5-HT2 receptor, can reverse the inhibition of α-methyl-5-HT. After intracellular dialysis of KN93 (CaMKII inhibitor) and H7 (PKC inhibitor), this inhibition was also completely eliminated. In conclusion, our results showed that α-methyl-5-HT inhibited ATP-activated current through activating the 5-HT2 receptor and resulting in phosphorylation of the ATP receptor. It was caused by the activation of G protein coupled receptor and corresponding intracellular signaling transduction cascade.

This paper discusses the synthesis and resulting catalytic performance of mesoporous alumina using aluminum isopropoxide as the aluminum source, and synthesized organosiloxane KH560-540 as template. The effects of the hydrothermal conditions, as well as the amount of templating agent at pH values of 5-9 on the structure of the synthesized mesoporous alumina were investigated by nitrogen adsorption-desorption methods, XRD and electron microscopy. Alumina from a rod-like scaffold structure was obtained, and the specific surface area was as high as 508 m2 g-1. Also, the coordination state of aluminum before and after calcination was analyzed by 27Al-NMR spectroscopy. The role of the templating agent in the synthesis process was determined. The synthesis mechanism of mesoporous alumina prepared by a KH560-540 template was also proposed. The acidity of samples that were synthesized by different templating agents were compared to NH3-TPD, and the content of Si in each sample was tested by ICP-OES, the results show that the silicon content has little effect on the acidity of the sample. Finally, we used the synthesized mesoporous alumina to catalyze the cyclization of dichloropropanol to epichlorohydrin, which showed excellent catalytic performance:dichlorohydrin conversion is up to 96% and epichlorohydrin yield of nearly 92%.

In this work, a series of PhnSnCl4-n (n = 1, 2, 3, and 4) based catalysts were prepared by incipient wetness impregnation using activated carbon (AC) as support and triphenyltin chloride (Ph3ClSn) and tin(IV) chloride (SnCl4) as Sn precursors. The obtained catalysts were systematically characterized by X-ray diffraction (XRD), N2 physisorption, Scanning electron microscope (SEM), Thermogravimetric analysis (TG-DTG), and Inductively coupled plasma (ICP) analytical techniques. The catalytic performance of the prepared PhnSnCl4-n samples was evaluated in the acetylene hydrochlorination reaction. When a gas hourly space velocity (GHSV, C2H2 based) and a reaction temperature of 30 h-1 and 200 ºC, respectively were used for the reaction performed over the 12% (1.0Ph3ClSn+3.5SnCl4)/AC-200 catalyst, an acetylene conversion of 98.0% with a selectivity to vinyl chloride of 98.5% were obtained. These results demonstrated that PhnSnCl4-n can effectively improve the catalytic activity and prolong the lifetime of SnCl4/AC catalysts. Moreover, by comparing with HgCl2/AC, PhnSnCl4-n-based catalysts exhibit much enhanced catalytic activity in the hydrochlorination of acetylene. It is assumed that the outstanding activity is due to trichlorophenylstannane (PhCl3Sn) active sites, resulted from the organotin redistribution reaction between Ph3ClSn and SnCl4. In addition, such sites also improved the SnCl4/AC catalyst stability during the reaction.