Esketamine accelerates emergence from isoflurane general anaesthesia by activating the paraventricular thalamus glutamatergic neurones in mice.

BACKGROUND: Delayed emergence from general anaesthesia poses a significant perioperative safety hazard. Subanaesthetic doses of ketamine not only deepen anaesthesia but also accelerate recovery from isoflurane anaesthesia; however, the mechanisms underlying this phenomenon remain elusive. Esketamine exhibits a more potent receptor affinity and fewer adverse effects than ketamine and exhibits shorter recovery times after brief periods of anaesthesia. As the paraventricular thalamus (PVT) plays a pivotal role in regulating wakefulness, we studied its role in the emergence process during combined esketamine and isoflurane anaesthesia. METHODS: The righting reflex and cortical electroencephalography were used as measures of consciousness in mice during isoflurane anaesthesia with coadministration of esketamine. The expression of c-Fos was used to determine neuronal activity changes in PVT neurones after esketamine administration. The effect of esketamine combined with isoflurane anaesthesia on PVT glutamatergic (PVTGlu) neuronal activity was monitored by fibre photometry, and chemogenetic technology was used to manipulate PVTGlu neuronal activity. RESULTS: A low dose of esketamine (5 mg kg-1) accelerated emergence from isoflurane general anaesthesia (474 [30] s vs 544 [39] s, P=0.001). Esketamine (5 mg kg-1) increased PVT c-Fos expression (508 [198] vs 258 [87], P=0.009) and enhanced the population activity of PVTGlu neurones (0.03 [1.7]% vs 6.9 [3.4]%, P=0.002) during isoflurane anaesthesia (1.9 [5.7]% vs -5.1 [5.3]%, P=0.016) and emergence (6.1 [6.2]% vs -1.1 [5.0]%, P=0.022). Chemogenetic suppression of PVTGlu neurones abolished the arousal-promoting effects of esketamine (459 [33] s vs 596 [33] s, P<0.001). CONCLUSIONS: Our results suggest that esketamine promotes recovery from isoflurane anaesthesia by activating PVTGlu neurones. This mechanism could explain the rapid arousability exhibited upon treatment with a low dose of esketamine.

Antimony tin oxide/lead selenide composite as efficient counter electrode material for quantum dot-sensitized solar cells.

Antimony tin oxide (ATO)/lead selenide (PbSe) composite was rationally designed and fabricated on fluorine doped tin oxide glass (FTO) for using as counter electrode (CE) of quantum dot sensitized solar cells (QDSSCs). The electrocatalytic activity of the CE is deeply investigated in the polysulfide electrolyte by employing the Tafel, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) of the symmetrical cells. The results confirm that the ATO/PbSe CE has better electrocatalytic activity and stability than that of PbSe CE obtained by pulse voltage electrodeposition (PVD). The enhanced electrocatalytic performance of ATO/PbSe CE can be attributed to its high specific surface area, excellent permeability, conductivity and interface connectivity, which provide more electrocatalytic active sites for the reduction of polysulfide species, as well as fast channels for ions diffusion and electron transport. As a result, the CdS QDSSCs and CdS/CdSe co-sensitized QDSSCs assembled by the ATO/PbSe CE exhibits better power conversion efficiency (η) of 1.72% and 5.59%, respectively than that of PbSe CE obtained by PVD. Furthermore, photovoltaic property of the ATO/PbSe CE in CdS/CdSe co-sensitized QDSSCs keeps stable for over 200 min. This present work provides a simple and effective strategy for the construction of high-performance CE materials of QDSSCs.

Voltage-assisted SILAR deposition of CdSe quantum dots to construct a high performance of ZnS/CdSe/ZnS quantum dot-sensitized solar cells.

The charge recombination on the interfaces of TiO2/quantum dots (QDs)/electrolyte is a key factor limiting the efficiency of quantum dot-sensitized solar cells (QDSSCs). Construction of double-layer barrier structure of ZnS/QDs/ZnS is a vital strategy to suppress the interfacial charge recombination. However, a large lattice mismatch (12%) at CdSe/ZnS interfaces causes CdSe to grow slowly on TiO2/ZnS mesoporous film, weakening the interaction between QDs and mesoporous film, which reducing the efficiency of CdSe QDSSCs with double ZnS barrier layers. Applying a voltage of 2 V in successive ionic layer adsorption reaction (VASILAR) to create an electric field, which assists Cd2+ and SeSO32- ions rapidly diffuse into the TiO2/ZnS mesoporous film to react forming CdSe QDs at room temperature. Optimizing the number of CdSe QDs deposition layers and combine with ZnS double-layer barrier structure, a best PCE of 4.34% for ZnS/CdSe/ZnS QDSSCs is achieved. This study gives a fast and simple approach to inhibit interfacial charge recombination to construct high performance CdSe QDSSCs.

[La-Ce-Codoping nano-titania photocatalyst: preparation via microwave-assisted sol process, spectroscopy characterization and photocatalytic activity].

La-Ce codoping nano-TiO2 catalyst was prepared by microwave-assisted sol process with TBT and distilled water as forerunner body, ethanol as solvent and glacial acetic acid as inhibitor. The prepared samples were characterized by using XRD, XPS and UV-Vis techniques. Results of structural characterization indicated that the prepared samples were all pure anatase phase nano-TiO2 and their diffraction peak broadened obviously after La and Ce doping. Results of XPS analysis revealed that La-O bond existed in the samples and many oxygen vacancies were produced on the surface of TiO2 nanoparticles after La and Ce codoping. UV-Vis absorption spectra demonstrated that the prepared samples had strong and wide absorption band between 200 and 400 nm and the absorption intensity increased after La and Ce doping because of La(III)-O charge-transfer transition, Ce (IV) f --> d transition and Ce (IV)-O charge-transfer transition. Photocatalytic experiment results showed that the titanium dioxide's photocatalytic activity increased obviously after La and Ce codoping. The optimal parameters for the preparation were obtained by adjusting the mole ratio of La and Ce in photocatalysts. When the doping amount of La and Ce was 2% and 0.04% respectively, the prepared sample exhibited high photocatalytic activity, the decoloration ratio of methyl orange solution was above 90%, and COD removal of cigarette factory wastewater was 86.11%.

Di-4-pyridyl disulfide-isophthalic acid (1/1).

In the title 1:1 cocrystal, C(10)H(8)N(2)S(2)·C(8)H(6)O(4), the asymmetric unit contains an isophthalic acid mol-ecule and a 4,4'-dipyridyl disulfide mol-ecule. The two carboxyl groups of isophthalic acid inter-act with neighbouring 4,4'-dipyridyl disulfide mol-ecules through O-H⋯N hydrogen bonds, forming a one-dimensional zigzag chain. Neighbouring chains are linked to each other via π-π stacking inter-actions between the pyridyl rings of adjacent 4,4'-dipyridyl disulfide mol-ecules [centroid-centroid distance = 3.7346 (6) Å], resulting in a layered motif. The dihedral angle between pyridine rings of 84.13 (7)° and the C-S-S-C torsion angle of 91.95 (1)° confirm the gauche conformation of 4,4'-dipyridyl disulfide.

[Study on spectroscopic properties of CuO nanoparticles].

The precursor Cu2 (NO3)(OH)3 was synthesized by homogeneous precipitation processing in ethanol-water(phi, 1 : 1) mixed solvent system using (CH2)6N4 as host-precipitates. CuO nanoparticles were prepared by heating Cu2 (NO3)(OH)3 at different temperatures. XRD, FTIR, XPS, FT-Raman and UV-Vis absorption spectra techniques were applied to investigated spectrum properties of CuO nanoparticles. All of the obtained samples were indicated to be monoclinic CuO under XRD measurement. Consistent with the XRD results, the XPS method also revealed that the atomic ratio of Cu to O in our samples was 1 : 1. With the increase in the calcinations temperature, the crystal of CuO grew up, the FTIR patterns revealed that the absorption of Cu-O and -OH bond in CuO nanoparticles blue-shifted and red-shifted at the same time, XPS spectrum indicated that the content of surface oxygen decreased, and the FT-Raman spectrum showed that the Raman scattering peak broadened with the decrease in the nano-CuO diameter; UV-Vis adsorption spectroscopy revealed that CuO has a wide adsorption peak at -350 nm, and the absorption edge blue-shifted with the size decreasing.

Bis(di-2-pyridylmethane-diol-κN,O,N')copper(II) dl-tartrate.

The reaction of di-2-pyridyl ketone with copper dichloride dihydrate and tartaric acid in water afforded the title compound, [Cu(C(11)H(10)N(2)O(2))(2)]C(4)H(4)O(6). The Cu(II) atom lies on an inversion center N,O,N'-chelated by two di-2-pyridylmethane-diol ligands in a tetragonally distorted octa-hedral geometry. The tartrate anion is also located on an inversion center and has disordered hydroxyl groups, each with an occupancy factor of 0.5. The hydroxyl groups of the complex cation are hydrogen bonded to the carboxyl-ate groups of the anion, thus connecting the two building units.