Capillary electrophoresis as a tool for screening aptamer with high affinity and high specificity to ricin

Aptamers which specifically recognize targets are selected from random oligonucleotide library using systematic evolution of ligands by exponential enrichment (SELEX). In this paper, capillary electrophoresis (CE) as a separation approach has been introduced to SELEX procedure. The high efficiency of CE gives rise to greatly shorten the selection procedure. The results from enzyme-linked assay and dot blot experiment show that an enrichment pool has been obtained after four rounds selection, which can specifically recognize ricin. __________ Translated from Chemical Journal of Chinese Universities, 2006, 27(10): 1,840–1,843 [译自: 高等学校化学学报]     

金银花的毛细管电泳指纹图谱研究

采用毛细管区带电泳法,以50 mmol/L硼砂(含20 mmol/L β-环糊精(CD),用磷酸调pH 8.0)为背景电解质,运行电压12 kV,紫外检测波长254 nm,重力进样15 s（高度8.5 cm）,建立了金银花药材水提取液的毛细管电泳指纹图谱(CEFP)。将13个不同产地的金银花药材供试液的CEFP进行比较,以电泳峰出现率100%计,确定金银花的共有指纹峰为18个。该CEFP具有较好的精密度和重现性,分离效能高且成本低廉。提出了指纹图谱宏观含量相似度R、投影含量相似度C和定量相似度P的概念,可从总体上评价药材化学组分的整体含量情况。从两个方面评价各产地药材与对照CEFP间的总体相似性,合格药材应具备以下两个条件：(1)代表化学成分分布相似性的定性相似度(S)≥0.90;(2)描述药材整体化学成分含量的定量相似度(R,C,P,Q)应在80%～120%。以此二类相似度指标控制金银花的质量,建立了指纹图谱评价的又一新方法。     

基础化学综合实验中学生“自主设计”的教学实践

在基础化学综合实验中,教师只提出主要原料和欲制备的产品大类,学生通过查找资料自主设计,用不同的方法、途径制备出所要求产品,并分析几种方法在操作过程、经济及环保等方面各自的优缺点,从而达到培养学生自主创新能力的目的.     

Microgel-based engineered nanostructures and their applicability with template-directed layer-by-layer polyelectrolyte assembly in protein encapsulation

A novel strategy for the fabrication of microcapsules is elaborated by employing biomacromolecules and a dissolvable template. Calcium carbonate (CaCO(3)) microparticles were used as sacrificial templates for the two-step deposition of polyelectrolyte coatings by surface controlled precipitation (SCP) followed by the layer-by-layer (LbL) adsorption technique to form capsule shells. When sodium alginate was used for inner shell assembly, template decomposition with an acid resulted in simultaneous formation of microgel-like structures due to calcium ion-induced gelation. An extraction of the calcium after further LbL treatment resulted in microcapsules filled with the biopolymer. The hollow as well as the polymer-filled polyelectrolyte capsules were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning force microscopy (SFM). The results demonstrated multiple functionalities of the CaCO(3) core - as supporting template, porous core for increased polymer accommodation/immobilization, and as a source of shell-hardening material. The LbL treatment of the core-inner shell assembly resulted in further surface stabilization of the capsule wall and supplementation of a nanostructured diffusion barrier for encapsulated material. The polymer forming the inner shell governs the chemistry of the capsule interior and could be engineered to obtain a matrix for protein/drug encapsulation or immobilization. The outer shell could be used to precisely tune the properties of the capsule wall and exterior. [Diagram: see text] Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).     

超高效液相色谱-三重四极杆质谱法测定血浆和尿液中马桑亭和马桑宁

建立了超高效液相色谱-三重四极杆质谱联用技术测定血浆和尿液中马桑中毒标志物马桑亭和马桑宁的方法。血浆和尿液样品经固相支持液液萃取法提取净化后，溶于15%（v/v）甲醇水溶液中，以Cortecs C₁₈色谱柱（100 mm×2.1 mm，1.6 μm）作为分析柱进行分离，电喷雾负离子多反应监测（MRM）模式下检测，以氟苯尼考作为内标物，基质工作曲线内标法定量。血浆和尿液中马桑亭和马桑宁的平均加标回收率为86.2%~110%，相对标准偏差为5.1%~14.6%（n=6），血浆中马桑亭和马桑宁的检出限（S/N=3）分别为0.01 μg/L和0.1 μg/L，尿液中马桑亭和马桑宁的检出限分别为0.03 μg/L和0.3 μg/L。本法简单、灵敏、准确，可用于血浆和尿液中马桑亭和马桑宁的中毒检测。     

Construction of Polycation‐Based Non‐Viral DNA Nanoparticles and Polyanion Multilayers via Layer‐by‐Layer Self‐Assembly

Summary: The multilayers of polycation‐based non‐viral DNA nanoparticles and biodegradable poly(L ‐glutamic acid) (PGA) were constructed by a layer‐by‐layer (LbL) technique. Poly(ethyleneimine) (PEI) was used to condense DNA to develop non‐viral DNA nanoparticles. AFM, UV‐visible spectrometry, and TEM measurements revealed that the PEI‐DNA nanoparticles were successfully incorporated into the multilayers. The well‐structured, easily processed multilayers with the non‐viral DNA nanoparticles may provide a novel approach to precisely control the delivery of DNA, which may have great potential for gene therapy applications in tissue engineering, medical implants, etc.

A TEM image of the cross section of a (PGA/PEI‐DNA nanoparticle)₂₀ multilayer.     

Catalytic conversions of chloroolefins over iron oxide nanoparticles 2. Isomerization of dichlorobutenes over iron oxide nanoparticles stabilized on the surface of ultradispersed poly(tetrafluoroethylene)

Nanosized iron oxides stabilized on the surface of ultradispersed poly(tetrafluoroethylene) (UPTFE) granules were synthesized by the thermal destruction of iron formate in boiling bed of UPTFE on the surface of heated mineral oil. The particle size of nanoparticles (∼6 nm) containing 5, 10, and 16 wt.% Fe depends weakly on the temperature of synthesis and iron to polymer ratio. The metal state is determined by the synthesis conditions. The nanoparticles synthesized at 280 °C consist mainly of the Fe₃O₄ and Fe₂O₃ phases. The samples obtained at 320 °C also contain iron(II) oxide. The catalytic properties of the obtained samples were tested in dichlorobutene isomerization. Unlike isomerization on the iron oxide nanoparticles supported on silica gel, reaction over the UPTFE supports proceeds without an induction period. The sample with 10 wt.% Fe containing magnetically ordered γ-Fe₂O₃ nanoparticles possesses the highest catalytic activity. Fast electron exchange between the iron ions in different oxidation states and high defectiveness of the nanoparticles contribute, most likely, to the catalytic activity. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1383–1390, June, 2005.     

Synthesis, IR-, NMR- and X-ray investigations on some novel N-hetaryl-dihydro-pyrazolyl ferrocenes. Study on ferrocenes, part 16

Cyclocondensation of 1-aryl-3-ferrocenyl-2-propen-1-ones (1) with hetaryl hydrazines resulted in N-hetaryl-3-aryl-5-ferrocenyl pyrazolines (3, 4). The analogous 3-aryl-1-ferrocenyl-2-propen-1-ones (5) gave the isomeric N-hetaryl-5-aryl-3-ferrocenyl-pyrazolines (6, 10), but in lower yield. The reaction of aryl-chalcones (7) with 4-hydrazino-phthalazinone led to 3,5-bis-aryl-N-hetaryl-pyrazolines (8) or to the corresponding ene-hydrazones (9). The structure of the new compounds was established by IR, ¹H and ¹³C NMR spectroscopy, including DNOE, HMQC, HMBC and DEPT methods. For compounds 1b, 3b and 8b the stereo structure was elucidated also by X-ray diffraction.     

CO2／CH4重整镍基催化剂制备与性能的关系

一般浸渍法与真空浸渍法的比较说明,真空浸渍制备的催化剂,其表面具有较多的Ｎｉ原子,催化活性较高,现场ＴＰＯ实验表明,ＣＯ岐化的积炭量大于ＣＨ４解离的积炭量。从而提出镍基催化剂的积炭主要来自反应生成气ＣＯ的岐化。     

Thermal Behaviour of Perfluoropolyether w/o Percolative Microemulsions

The thermal properties of a perfluoropolyether (PFPE) W/O microemulsion were investigated by Differential Scanning Calorimetry (DSC) both on freezing the liquid samples and upon their melting. PFPE systems as a function of increasing volume fraction (Φ=water+surfactant/total), were studied along a dilution line with a water/surfactant molar ratio W/S=11. The percolative nature of these systems emerged directly from the spreading of the exothermic peaks associated with the freezing of the dispersed phase. This behaviour was found to depend on whether the starting temperature of the DSC measure was at, below or above the percolative threshold temperature of the given sample. A low temperature 'needle-like' peak was found around 143 K, immediately after the glass transition due to the oil continuous phase. The low temperature peak was also present in other percolative, three-component microemulsions. The higher order phase transition at the percolation temperature was also evidenced. This revised version was published online in August 2006 with corrections to the Cover Date.