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For the conversion of fructose/methylglucoside (MG) into both methyl formate (MF) and methyl levulinate (MLev), the C-source of formate [HCOO]− remains unclear at the molecular level. Herein, reaction mechanisms catalyzed by [CH3OH2]+ in a methanol solution were theoretically investigated at the PBE0/6-311++G(d,p) level. For the conversion of fructose into MF and MLev, the formate [HCOO]− comes from the C1-atom of fructose, in which the rate-determining step lies in the reaction of 5-hydroxymethylfurfural (HMF) with CH3OH to yield MF and MLev. The reaction of fructose with CH3OH kinetically tends to generate HMF intermediates rather than yield (MF + MLev). When MG is dissolved in a methanol solution, its O2, O3, and O4 atoms are closer to the first layer of the solvent than O1, O5, and O6 atoms. For the dehydration of MG with methanol into MF and MLev, the formate [HCOO]− stems from the dominant C1- and secondary C3-atoms of MG. Kinetically, MG is ready to yield (MF + MLev), whereas fructose can induce the reaction to remain at the HMF intermediate, inhibiting the further conversion of HMF with CH3OH into MF and MLev. If MG isomerizes into fructose, the reaction will be more preferable for yielding HMF rather than (MF + MLev). [ABSTRACT FROM AUTHOR]

The enhancement of photocatalytic semiconductor degradation performance through a bismuth‐rich strategy and heterojunction engineering is considered a very effective approach. Herein, the bismuth‐rich Bi3O4Cl/BixOyIz composites are synthesized through a simple solvothermal reaction. The composites have an internal electric field because of their specific layered structure. Due to the difference between their covalent [BixOy]2+ layer and exchangeable halogen ion layer, the enhanced internal electric field facilitates electron transfer at the high‐quality interface of the semiconductor. The trace presence of Bi3O4Cl/BixOyIz (0.1 g L−1) can achieve an 88% removal of tetracycline (20 mg L−1) from the solution phase under visible light illumination in 120 min. The photocatalytic activity is much higher than that of pure BiOCl and BiOI. Furthermore, the material also exhibits high photocatalytic degradation performance for bisphenol A, doxycycline hydrochloride, etc. The excellent results further confirm the application range of the prepared photocatalysts. The superior photocatalytic activity of Bi3O4Cl/BixOyIz is attributed to the formation of a heterojunction and the generation of an internal electric field, which enhances charge separation and oxidation ability. Photoelectrochemical characterization can confirm the above views. Free radical trapping experiments and electron spin resonance show that heterojunctions can produce abundant •O2− and •OH under visible light irradiation. [ABSTRACT FROM AUTHOR]

Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy (TLE). We postulated that kainic acid (KA)-Induced status epilepticus triggers microglia-dependent inflammation, leading to neuronal damage, a lowered seizure threshold, and the emergence of spontaneous recurrent seizures (SRS). Extensive evidence from our laboratory suggests that dextromethorphan (DM), even in ultra-low doses, has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease. Our results showed that administration of DM (10 ng/kg per day; subcutaneously via osmotic minipump for 4 weeks) significantly mitigated the residual effects of KA, including the frequency of SRS and seizure susceptibility. In addition, DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss. We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91phox and p47phox proteins in KA-induced chronic TLE rats. Notably, even after discontinuation of DM treatment, ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects, which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies. [ABSTRACT FROM AUTHOR]