A single-strand conformation polymorphism method by capillary electrophoresis with laser-induced fluorescence for detection of the T1151A mutation in hMLH1 gene

Mutation of hMLH1 gene plays an important role in human tumorigenesis. A highly sensitive single-strand conformation polymorphism (SSCP) method for detection of the T1151A mutation in exon 12 of the hMLH1 gene was for the first time developed employing laser-induced fluorescence capillary electrophoresis (LIF-CE). Effects of the concentration of linear polyacrylamide solution, running temperature, running voltage and the addition of glycerol on SSCP analysis were investigated, and the optimum separation conditions were defined. Thirty colorectal cancer patients and eight lung cancer patients were screened and the T1151A mutation was found in four of them. Based on CE-sequencing the mutation was further confirmed. To our knowledge, this is for the first time that the T1151A mutation is found in lung cancer. Our method is simple, rapid, and highly sensitive and is well suited to the analysis of large numbers of clinical samples.     

Inserting Thienyl Linkers into Conjugated Molecules for Efficient Multilevel Electronic Memory: A New Understanding of Charge‐Trapping in Organic Materials

The practical application of organic memory devices requires low power consumption and reliable device quality. Herein, we report that inserting thienyl units into D–π–A molecules can improve these parameters by tuning the texture of the film. Theoretical calculations revealed that introducing thienyl π bridges increased the planarity of the molecular backbone and extended the D–A conjugation. Thus, molecules with more thienyl spacers showed improved stacking and orientation in the film state relative to the substrates. The corresponding sandwiched memory devices showed enhanced ternary memory behavior, with lower threshold voltages and better repeatability. The conductive switching and variation in the performance of the memory devices were interpreted by using an extended‐charge‐trapping mechanism. Our study suggests that judicious molecular engineering can facilitate control of the orientation of the crystallite in the solid state to achieve superior multilevel memory performance.     

Negative effect on molecular planarity to achieve organic ternary memory: triphenylamine as the spacer

Adjusting the spacers between the electron-acceptor and the elector-donor is important to design organic ternary memory material but rarely reported. In this paper, two small molecules, ZIPGA and ZIPCAD with benzene ring or triphenylamine as the spacers, were designed and synthesized to fabricate memory devices. The Al/ZIPGA/indium-tin oxide (ITO) device showed ternary characteristics, whereas Al/ZIPCAD/ITO had no obvious memory characteristics. Density functional theory calculation, X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to interpret the different memory properties. ZIPGA thin film has the closer intermolecular packing and flatter surface morphology than ZIPCAD film, which was favorable to the electron migration. This work demonstrates the importance of spacers and reveals that triphenylamine may be not a good spacer in design of new memory material.     

Superhydrophobic surface fabricated by bulk photografting of acrylic acid onto high-density polyethylene

A superhydrophobic polymeric surface was prepared through a very simple bulk photografting method. A thin layer of acrylic acid (AA), a highly hydrophilic monomer, was sandwiched between two high-density polyethylene (HDPE) sheets, followed by UV irradiation for a short time, and then the two sheets were pulled apart and dried. The contact angles on the two grafted surfaces decreased very quickly with irradiation time in the first several seconds, and then increased with irradiation time to a level higher than that on pristine HDPE surface. When using a scraped PE surface as the bottom one, it showed superhydrophobicity after 35 s irradiation. XPS investigations show that strong rearrangement of the poly(acrylic acid) molecules has taken place on both surfaces, especially on the bottom surface, which provides the low surface free energy. The scraping and the grafting process led to the formation a unique micro- and nanostructure on the surface. These two factors lead to the superhydrophobicity. The as-prepared surface possesses superhydrophobic properties in a wide range of pH values, stimuli-responsive properties and low or very high adhesion under different situations.     

Hydrophobicity and mixing effects on select heterogeneous, water-accelerated synthetic reactions

The influence of aqueous reaction media on organic reactions is a topic of long-standing interest, particularly as it affects the rate or selectivity of synthetic reactions. Sometimes such reactions appear homogeneous, typically in dilute solution, whereas others are obviously heterogeneous, typically in concentrated solution that is more characteristic of a preparative synthetic reaction. The latter situation has been termed "on water." Here, it is demonstrated that the rates of heterogeneous ene reactions, Passerini reactions, and Ugi reactions in pure water and in aqueous solutions are dependent on the mixing method and reactant polarity, consistent with the involvement of hydrophobic interactions in their acceleration.     

超声作用下MCM-36分子筛的快速合成

以四甲基铵硅酸盐为柱化剂,考察了超声作用对MCM-36分子筛合成的影响.结果表明,超声处理显著缩短了柱化剂进入已撑开的MCM-22(P)层间的插层过程的时间.通过控制插层过程的超声时间可以合成出具有不同层间距的MCM-36分子筛,而且合成的MCM-36分子筛内各层的层间距较均一.     

6-Br-苯并噻唑重氮氨基偶氮苯的合成及其与镉(Ⅱ)的显色反应研究

合成了新三氮烯类试剂——６－Ｂｒ－苯并噻唑重氮氨基偶氮苯。通过红外光谱和元素分析等验证了其结构,研究了试剂与镉（Ⅱ）的显色反应。结果表明,该试剂是测定微量镉（Ⅱ）的高灵敏显色剂之一,其ε值达２．２３×１０５Ｌ·ｍｏｌ－１·ｃｍ－１,并且有较好的选择性。用拟定的方法测定了废水中的微量镉,结果令人满意     

三氮唑衍生物随pH变化的双稳态性质

本文设计合成了一系列以三氮唑为电子受体的双生色团化合物。光谱研究表明这些分子的发光性质不仅取决于电子转移驱动力,也取决于间隔基和电子给体的尺寸。有些分子的发光在pH1～3范围内发生急剧变化,荧光量子产率相对于pH值的变化是一个双稳体系而具有光控分子开关性质。     

氟化物体系中老化方式对合成MCM-22分子筛的影响

 以氟化钠为矿化剂、六亚甲基亚胺为模板剂,在静态水热条件下考察了静态老化、动态老化及超声老化对合成MCM-22分子筛的影响. 实验结果表明,三种老化方式对合成MCM-22分子筛均有促进作用,其中超声老化的促进作用最明显. 采用超声老化的方法,在氟化物体系中使MCM-22分子筛可合成SiO2/Al2O3摩尔比范围扩大到 20～100, 合成时间缩短到 48～62 h, 同时分子筛的形貌发生了改变.     

小身材,大能量——氢气

氢气(H_2),自然界中最小的分子,最轻的气体,在我们的生活中具有非常重要的作用,对人体的多种疾病具有显著的预防和治疗效果,是一种重要的工业原料,是最具发展前景的清洁能源。本文对氢气的发现史以及氢气在医学健康、合成化学中的作用进行阐述。