The catalytic performance study of polymerized ionic liquid synthesized in different conditions on alkylation of o‐Xylene with styrene

In this work, a series of novel acidic polymerized ionic liquids were used as heterogeneous catalyst for alkylation of o‐Xylene with styrene. And the effect of the amount of initiator and the type of acid used for ion exchange on catalyst structure and the catalytic performance of catalysts for alkylation were studied thoroughly. The experiment results show: when the percentage of the amount of initiator in the total material is 3%, the polymerized ionic liquid catalyst MPM‐SO₃H‐[C₃V][SO₃CF₃] has the most uniform with a specific surface area of 97.30 m²/g and a pore volume of 0.35 cm³/g. Benefiting from the unique structure features, MPM‐SO₃H‐[C₃V][SO₃CF₃] manifested an excellent catalytic performance for alkylation of o‐Xylene with styrene, along with the conversion of styrene was 96.8% and the yield of 1‐Phenyl‐1‐ortho‐xylene ethane was 94.7%. Therefore, this work provides a novel reference to the synthesis of polymerized ionic liquids and clearly explains the advantage of novel acidic polymerized ionic liquids on alkylation.     

Reversible M−M Bonding by Alkaline Earth Metals (Mg,Ca, Sr,Ba) in Graphite Intercalation Compounds

The alkaline earth metals (M=Mg, Ca, Sr, and Ba) exhibit a +2 oxidation state in nearly all known stable compounds, but M^I dimeric complexes with M−M bonding, [M₂(en)₂]²⁺, (en=ethylenediamine) of all these metals can be stabilized within the galleries of donor-type graphite intercalation compounds (GICs). These metals can also form GICs with more conventional metal (II) ion complexes, [M(en)₂]²⁺. Here, the facile interconversion between dimeric-M^I and monomeric-M^II intercalates upon the addition/removal of en are reported. Thermogravimetry, powder X-ray diffraction, and pair distribution function analysis of total scattering data support the presence of either [M₂(en)₂]²⁺ or [M(en)₂]²⁺ guests. This phase conversion requires coupling graphene and metal redox centers, with associated reversible M−M bond formation within graphene galleries. This chemistry allows the facile isolation of unusual oxidation states, reveals M⁰→M²⁺ reaction pathways, and present new opportunities in the design of hybrid conversion/intercalation materials for applications such as charge storage.     

Phase separation dynamics of a poly(vinyl methyl ether)/polystyrene (PVME/PS) blend studied by ultrafast differential scanning calorimetry

In this work, ultrafast differential scanning calorimetry (UFDSC) is used to study the dynamics of phase separation. Taking poly(vinyl methyl ether)/polystyrene (PVME/PS) blend as the example, we firstly obtained the phase diagram that has lower critical solution temperature (LCST), together with the glass transition temperature (T_g) of the homogeneous blend with different composition. Then, the dynamics of the phase separation of the PVME/PS blend with a mass ratio of 7:3 was studied in the time range from milliseconds to hours, by the virtue of small time and spatial resolution that UFDSC offers. The time dependence of the glass transition temperature (T_g) of PVME‐rich phase, shows a distinct change when the annealing temperature (T_a) changes from below to above 385 K. This corresponds to the transition from the nucleation and growth (NG) mechanism to the spinodal decomposition (SD) mechanism, as was verified by morphological and rheometric investigations. For the SD mechanism, the temperature‐dependent composition evolution in PVME‐rich domain was found to follow the Williams–Landel–Ferry (WLF) laws. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1357–1364     

The introduction of antibacterial drug pipemidic acid into the POM field: Syntheses, characterization and antitumor activity

Two new compounds based on polyoxometalates (POMs) and the quinolone antibacterial drug pipemidic acid (HPPA), {[Ni(PPA)₂]H₄[SiW₁₂O₄₀]}·HPPA·3H₂O (1), and {[Zn(PPA)₂]₂H₄[SiW₁₂O₄₀]}·3H₂O (2), have been synthesized under hydrothermal conditions and structurally characterized by routine technique. Single-crystal X-Ray diffraction analysis shows that compound 1 is constructed by Keggin clusters grafted by binuclear nickel clusters, isolated HPPA and water molecules, while compound 2 consists of Keggin clusters grafted by binuclear zinc clusters and water molecules. Due to the selection of different transition metal (TM) ions, compounds 1 and 2 exhibit different structures and antitumor activities. Compound 1 possesses 0D structure and shows no antitumor activities. However, compound 2 possesses 1D structure and exhibits higher antitumor activities than its parent compound. The results show that introduction of different TM-PPA moieties onto the polyoxoanion surface can affect not only the final structures but also their antitumor activities.     

茚三酮衍生高效毛细管电泳法测定纯奶中的甘氨酸含量

建立了茚三酮衍生高效毛细管电泳法测定纯奶中甘氨酸含量的方法,该法可选择性测定甘氨酸含量。使用氯化镁为蛋白沉淀剂,沉淀效果较好,研究了甘氨酸–茚三酮聚合物衍生条件,确定最佳实验条件为:未涂层弹性石英毛细管柱(60 cm×75μm,有效长度49 cm),分离缓冲溶液为3.5 mmol磷酸二氢钾–8.2 mmol磷酸氢二钠(pH 6.8),检测波长为570 nm,电泳电压为25 kV,进样压力为25 kPa,进样时间为3 s,电泳温度为室温。甘氨酸的线性范围为2.00~200.00μg/mL,检出限为0.14μg/mL,线性相关系数不小于0.999。甘氨酸的加标回收率为88.7%~107.2%,测定结果的相对标准偏差为2.9%~4.2%(n=6)。该法简便、快速、准确,可用于测定纯奶中甘氨酸含量。     

Electrochemical assay of the relationship between the inhibition of phosphatidylinositol 3-kinase pathway and estrogen receptor expression in breast cancer

Breast cancer has become one of the most threatening diseases to women throughout the world. Emerging evidence implies that estrogen receptor (ER) and phosphatidylinositol 3-kinase (PI3K) pathways play central roles in both breast cancer progression and response to therapy. In this work, we have probed into ER expression related to the PI3K pathway at the protein level with an electrochemical technique based on the detection of ER proteins in nuclear extracts with an Exonuclease III protection-based strategy. Experimental results show that an increased number of ER proteins can be detected upon PI3K inhibition, demonstrating the reversal effect of the PI3K inhibitor on ER expression. Moreover, treatment with different concentrations of the PI3K inhibitor NVP-BEZ235 can result in a dose-dependent alteration of ER protein levels, implying an intimate link between ER and PI3K pathways. This work may be a great help to understand the mysteries underlying PI3K-related endocrine resistance and to evaluate the effect of therapeutic interventions in the future.     

氧化铝载体对Pt-Sn-K/γ-Al2O3催化剂上异丁烷脱氢性能的影响

采用盐酸回流法和氨水沉淀法合成了氧化铝载体,并通过络合真空浸渍法制备了不同来源氧化铝负载的Pt-Sn-K/γ-Al₂O₃催化剂。利用N₂物理吸附、CO脉冲吸附、H₂程序升温还原、NH₃程序升温脱附、热重等手段对Pt-Sn-K/γ-Al₂O₃催化剂进行了表征,以异丁烷脱氢为探针反应研究了氧化铝载体对该催化剂脱氢性能的影响。结果表明,与由盐酸回流法合成的载体制备的催化剂相比,采用氨水沉淀法合成的氧化铝载体制备的Pt-Sn-K/γ-Al₂O₃催化剂表面具有较小的Pt颗粒和较弱的酸性分布,其脱氢活性及异丁烯选择性更优。14 d的连续运行数据显示,由氨水沉淀合成的载体制备的催化剂,其抗积炭能力更强,反应后催化剂的积炭石墨化程度更低,因而具有更好的稳定性;在该催化剂上,异丁烷初始转化率为56.67%,14 d后仍能达到34.71%,异丁烯初始选择性为80%,7 d后维持在94%左右。     

基于核酸分子杂交的免疫芯片抗体固定新方法

基于核酸分子杂交原理构建了一种新型抗体固定方法.先将抗体与寡核苷酸单链交联,再将两者的复合物与固相载体表面上的互补寡核苷酸链结合,从而将抗体固定到载体的表面.在磁珠表面对该固定方法进行实验,证明了方法的可行性.以本方法构建了针对转基因Bt Cry1Ac蛋白的免疫芯片,用Cy3标记二抗对其探针固定效果进行分析,并且在芯片上对Bt Cry1 Ac蛋白进行梯度浓度检测试验.结果表明,以本方法构建的抗体芯片,探针分布具有良好的特异性;探针层分布均匀,非特异吸附小;检测灵敏度达到0.01 ～ 0.05 μg/L;此外,通过杂交核酸双链的解离成功实现了芯片的再生,有助于解决传统抗体固定方法中芯片不可再生的问题.     

Simultaneous extraction and determination of fluoroquinolones,tetracyclines and sulfonamides antibiotics in soils using optimised solid phase extraction chromatography-tandem mass spectrometry

An analytical method was developed for the simultaneous extraction and determination of 18 fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) antibiotics from soils using solid phase extraction and liquid chromatography-tandem mass spectrometry. The soils were extracted by different solvents with the help of mechanical shaking and ultrasonic treatment at 59?kHz, followed by a strong anion exchange (SAX) cartridge to clean up soil samples and a hydrophilic lipophilic balance (HLB) cartridge as enrichment. The method was evaluated by testing the following variables: extraction solvents, the type of SPE cartridges, solvent volumes, initial spiking levels and soil types (silty clay loam and clay loam soils). The soil extraction method was validated using these two types of soils, representing two typical agricultural soils in northern China. For 2?g soil, the extraction steps with the mixture of potassium phosphate buffer and acetonitrile (ACN) (1/1, v/v, pH 3.2) provided satisfactory recoveries. In the clay loam soil, the recoveries of all the compounds were from 56% to 89% at the spiking level of 50?µg?kg^?1 soil, and from 69% to 97% at the spiking level of 200?µg?kg^?1 soil, respectively. Recoveries in silty clay loam soil were similar to that in clay loam. The method was successfully employed using soil samples collected from a farmland and afforestion area irrigated with sewage in northern China. The result indicates that trace antibiotics in sewage may accumulate in soil irrigated by river water containing sewage.