Static Charge Susceptibility in the <Emphasis Type="Italic">t-J-V</Emphasis> Model

We describe the static charge susceptibility and correlation function of the charge density in the twodimensional t-J-V model based on the method of equations of motion for the relaxation functions of the Hubbard operators. We obtain the dependence of the susceptibility and correlation function on the hole concentration and temperature. Charge density waves can develop if the intersite Coulomb interaction is sufficiently strong.     

New nor-oleanane triterpenoids from the fruits of Stauntonia brachyanthera with potential anti-inflammation activity

Abstract

The continuing studies on the fruits of Stauntonia brachyanthera led to the isolations of 6 normal and nor-oleanane triterpenoids, including two new compounds, brachyantheoraside B10 (1) and brachyantheraside C1 (2). Compounds 1–3 showed inhibitory activity on lipopolysaccharide (LPS)-induced nitric oxide production in RAW 264.7 macrophages with the IC₅₀ values of 27.04, 26.22, and 21.41?μM, respectively, which were all stronger than that of indomethacin. The study not only revealed a new type of nor-oleanane triterpenoids, but also confirmed the anti-inflammation abilities of three type nor-oleanane triterpenoids as the inhibitors of NO production.     

Stabilizing DNAzymes through Encapsulation in a Metal–Organic Framework

DNAzymes are a promising class of bioinspired catalyst; however, their structural instability limits their potential. Herein, a method to stabilize DNAzymes by encapsulating them in a metal–organic framework (MOF) host is reported. This biomimetic mineralization process makes DNAzymes active under a wider range of conditions. The concept is demonstrated by encapsulating hemin-G-quadruplex (Hemin-G4) into zeolitic imidazolate framework-90 (ZIF-90), which indeed increases the DNAzyme's structural stability. The stabilized DNAzymes show activities in the presence of Exonuclease I, organic solvents, or high temperature. Owing to its elevated stability and heterogeneous nature, it is possible to perform catalysis under continuous-flow conditions, and the DNAzyme can be reactivated in situ by introducing K⁺. Moreover, it is found that the encapsulated DNAzyme maintains its high enantiomer selectivity, demonstrated by the sulfoxidation of thioanisole to (S)-methyl phenyl sulfoxide. This concept of stabilizing DNAzymes expands their potential application in chemical industry.     

A novel Cr turn-on probe based on naphthalimide and BINOL framework

Naphthalimide and BINOL framework based fluorescent probe NP-B was rationally designed and synthesized. NP-B exhibited ‘turn-on’ fluorescence for Cr³⁺ and high selectivity over other metal ions. 1:1 binding mode between NP-B and Cr³⁺ was proposed and the mode was verified through MALDI-TOF mass spectrum. The detection limit was calculated to be 0.20 μM, which indicated the good sensitivity for Cr³⁺.     

Simultaneous determination of five triterpene acids in rat plasma by liquid chromatography–mass spectrometry and its application in pharmacokinetic study after oral administration of Folium Eriobotryae effective fraction

Folium Eriobotryae effective fraction (FEA), the extract of Folium Eriobotryae, had been used as anti‐hyperglycemia and anti‐hyperlipemia medicine in China. A previous study indicated that euscaphic acid, maslinic acid, corosolic acid, oleanolic acid and ursolic acid, the five structurally similar triterpene acids (containing two groups of structural isomers), are the major components of FEA. In the present study, we developed a specific and reliable LC‐MS method for simultaneous determination of the five triterpene acids in rat plasma, and further investigated their pharmacokinetic properties after oral administration of FEA. Following a simple sample preparation, chromatographic separation was achieved on a C₁₈ column with a mobile phase composed of methanol–0.1% ammonium acetate (80:20, v/v). Quantification was achieved by monitoring the selected ions at m/z 487.6 for euscaphic acid, m/z 471.5 for maslinic acid and corosolic acid, m/z 455.5 for oleanolic acid and ursolic acid and m/z 469.5 for internal standard. The method was validated to be specific, accurate and precise over the concentration ranges of 10–3000 ng/mL with limits of detections of 5 ng/mL for the five triterpene acids. Finally, the method was successfully applied to the pharmacokinetic study of the five structurally similar triterpene acids in rats after oral administration of FEA. Copyright © 2015 John Wiley & Sons, Ltd.     

无机化学元素教学中运用混合教学模式的探索

针对无机化学教学中,元素部分内容庞杂细碎、描述性内容多的特点,采用混合式教学模式,结合传统的面授教学和数字化网络教学的优势,使丰富的教学资源多样化呈现、重要知识点多方位训练。同时,对原有的教学内容、教学方法和考核评价等方面进行了全面改进,建立起以学生为中心、以教师引导为辅的主动学习模式。初步实践表明,博采众长的混合式教学模式受到学生的普遍欢迎,对强化个性化教学、提高教学效果、培养创新能力有积极的意义。     

以电化学方法在离子液体[DEME][BF4]中合成铂纳米粒子

通过恒电位电沉积法在离子液体N,N-二乙基-N-甲基-N-（2-甲氧基乙基）铵四氟硼酸铵（[DEME][BF₄]）中,在玻碳电极上制备了铂纳米颗粒。首先探究了不同沉积电势和不同沉积时间对铂纳米粒子微观形貌的影响,由SEM和TEM图发现在-2.5 V下沉积480 s制备的铂纳米粒子的平均粒径约为2.38 nm。使用高分辨率透射电子显微镜（HRTEM）和电子衍射（SAED）对其晶体结构进行表征,证明了铂纳米粒子为面心立方（fcc）晶体结构。在硫酸中测试铂纳米粒子的催化性能,发现其暴露出明显的（110）和（100）晶面。进一步对铂的电沉积行为进行研究发现,Pt（Ⅳ）的两步还原是由扩散过程和电化学过程共同控制。     

片段法合成抗骨质疏松多肽药物特立帕肽

将特立帕肽序列中的34个氨基酸分成4个片段:1-11、 12-16、 17-24和25-34;以Wang Resin（王树脂）为固相载体制得25-34肽树脂;以CTC Resin（2-氯三苯甲基氯树脂）为固相载体制得1-11、 12-16和17-24等3个片段的全保护肽,然后将3个片段的全保护肽按照肽序依次缩合到25-34的肽树脂上,经三氟乙酸切割并脱除侧链保护基得特立帕肽粗品,再经液相色谱纯化得特立帕肽,纯度大于99%,总收率达33%,其结构经MS(ESI)确证。