Fe 3+ -doped g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite catalysts were prepared by a simple method using melamine and ferric nitrate as precursors. X-ray diffraction, UV-Vis spectroscopy, Fourier transform infrared spectra, scanning electron microscopy, photoluminescence, X-ray photoelectron spectroscopy and photocurrent measurements were used to characterize the prepared catalysts. The results indicated that Fe 3+ was inserted at an interstitial position of g-C 3 N 4 by coordinating to N atoms, which exist in a form completely different from those in the Fe 2 O 3 /g-C 3 N 4 composite. The different form of Fe species caused the difference in optical properties, energy band structure and electrons-holes separation rate.The activities of Fe 3+ -doped g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite catalysts were tested by the photocatalytic degradation of Rhodamine B (RhB) under visible light. The rate constant of Fe 3+ -doped g-C 3 N 4 was 2.5 and 1.8 times higher than that of the g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite. The possible mechanism is proposed.

Graphitic carbon nitride (g-C 3 N 4 ) doped with the rare earth metal Ce was prepared by a simple method using melamine and Ce(SO 4 ) 2 Á4H 2 O as precursors. X-ray diffraction (XRD), UV-vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared catalysts. The results indicate that the introduction of Ce inhibits the crystal growth of g-C 3 N 4 , decreases the bandgap energy, and increases the separation efficiency of photogenerated electrons and holes. The activities of Ce-doped g-C 3 N 4 catalysts were tested in the photocatalytic degradation of rhodamine B (RhB) under visible light. The rate constant of Ce-doped g-C 3 N 4 is 2.1 × that of neat g-C 3 N 4 . A possible mechanism is proposed.

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Context: Triterpenes from Poria cocos Wolf (Polyporaceae) have been used to treat various diseases in traditional Chinese medicine. However, the antiepileptic effects and mechanism are not fully understood. Objective: The objective of this study is to investigate the antiepileptic properties of total triterpenes (TTP) from the whole P. cocos. Materials and methods: The ethanol extract TTP was identified by HPLC fingerprint analysis. Male ICR mice were gavaged (i.g.) with TTP (5, 20, 80 or 160 mg/kg) or reference drugs twice a day for 7 d. Antiepileptic activities of TTP were evaluated by maximal electroshock (MES)-and pentylenetetrazole (PTZ)-induced seizures in mice for 30 and 60 min, respectively. Locomotor activity and Rota-rod tests were performed for 60 min and 5 min, respectively. The levels of glutamic acid (Glu), aspartic acid (Asp), c-aminobutyric acid (GABA) and glycine (Gly) in convulsive mice were estimated. The chronic epileptic model of Wistar rats was built to measure expressions of glutamate decarboxylase 65 (GAD65) and GABA A in rat brain after TTP treatment. Results: The LC 50 of TTP (i.g.) was above 6 g/kg. TTP (5-160 mg/kg) protected mice against MES-and PTZinduced convulsions at 65.0% and 62.5%, respectively, but have no effect on rota-rod treadmill; TTP (20-160 mg/kg) significantly reduced the locomotor activities, shortened the onset of pentobarbital sodium-induced sleep; TTP decreased Glu and Asp levels in convulsive mice, but increased the GAD65 and GABA A expressions in chronic epileptic rats at doses usage. Discussion and conclusion: TTP extracted from P. cocos possessed potential antiepileptic properties and is a candidate for further antiepileptic drug development. ARTICLE HISTORY

摘要: 以硝酸铁和三聚氰胺为原料制备不同含铁量的 Fe 掺杂石墨氮化碳(g-C3N4). 采用 X 射线衍射光谱 (XRD)、 紫外-可见(UV-Vis)光谱、 傅里叶变换红外(FT-IR)光谱、 电感耦合等离子体-原子发射光谱(ICP-AES)、 荧 光(PL)光谱、 X 光电子能谱(XPS)等分析手段对制备的催化剂进行了表征. 结果表明, 铁以离子形式镶嵌在 g-C3N4的结构单元中, 影响了 g-C3N4的能带结构, 增加了 g-C3N4对可见光的吸收, 降低了光生电子-空穴对的复合 几率. 以染料罗丹明 B 的降解为探针反应系统研究了不同含铁量对 g-C3N4在可见光下催化性能的影响. 结果表 明, m(Fe)/m(g-C3N4)=0.14%时, 制备的 Fe 掺杂 g-C3N4表现出最佳的光催化性能, 120 min 内罗丹明 B 的降解 率高达 99.7%, 速率常数达到 0.026 min-1 , 是纯 g-C3N4的 3.2 倍. 以叔丁醇、 对苯醌、 乙二胺四乙酸二钠为自由 基(•OH)、 自由基(O2-•)和空穴(h + VB)的捕获剂, 研究了光催化反应机理.