基于多巴胺-量子点的比色免疫分析法对甲胎蛋白的高灵敏检测

基于抗原抗体识别特异性,以多巴胺-Mn/ZnS量子点(DA-QDs)为反应媒介,紫外可见分光光度计为检测手段,采用柠檬酸钠还原法制备金纳米颗粒(AuNPs),其表面用辣根过氧化物酶(HRP)和羊抗小鼠免疫球蛋白G (IgG)修饰获得功能化二抗(IgG-AuNPs-HRP)作为信号放大标签,构建一种简便高灵敏的检测方法....     

高保偏聚合物光子晶体光纤的化学制备技术研究

研究了大尺寸高保偏聚合物光子晶体光纤（polymer Photonic Crystal Fibers,pPCFs）预制棒的化学原位制备技术.采用预聚物浇铸后加热聚合方法,成功制备了具有高保偏性能的光纤预制棒, 给出了聚合反应的最佳条件.对此预制棒进行二次拉伸及光学和化学性质的测试表明,该方法得到的预制棒力学结构稳定、光学透明度高,且拉伸所得光纤微结构保持完好、微孔坍塌率低、非固有损耗小.若在聚合反应体系中加入适量的激光染料或其它稀土有机螯合物等物质,可得到具有荧光性的高保偏聚合物光子晶体光纤预制棒,为保偏型聚合物光子晶体光纤激光器的研制提供新材料.     

高压离子交换排代法富集锂同位素(Ⅲ)——半连续富集

本文对同位素富集总量随排代距离的变化规律及同位素的半连续富集过程进行了研究,本法可用于同位素富料的再富集。     

智能高分子材料在智能给药系统中的应用

简要介绍了合成智能高分子材料、半合成智能高分子材料和天然智能高分子材料在智能给药系统中的应用研究进展,并展望了其在智能给药系统中的应用前景。     

Functional colloidal particles stabilized by layered silicate with hydrophilic face and hydrophobic polymer brushes

In this study, we describe a new strategy for producing narrowly dispersed functional colloidal particles stabilized by a nanocomposite with hydrophilic clay faces and hydrophobic polystyrene (PS) brushes on the edges. This method involves preparation of polymer brushes on the edges of clay layers and Pickering suspension polymerization of styrene in the presence of the nanocomposites. PS brushes on the edges of clay layers were prepared by atom transfer radical polymerization. X‐ray diffraction and thermogravimetric analysis results indicated that PS chains were grafted to the edges of clay platelets. Transmission electron microscope results showed that different morphologies of clay‐PS particles could be obtained in different solvents. In water, clay‐PS particles aggregated together, in which PS chains collapsed forming nanosized hydrophobic domains and hydrophilic clay faces stayed in aqueous phase. In toluene, clay‐PS particles formed face‐to‐face structure. Narrowly dispersed PS colloidal particles stabilized by clay‐PS were prepared by suspension polymerization. Because of the negatively charged clay particles on the surface, the zeta potential of the PS colloidal particles was negative. Positively charged poly(2‐vinyl pyridine) (P2VP) chains were adsorbed to the surface of PS colloidal particles in aqueous solution at a low pH value, and gold nanoparticles were prepared in P2VP brushes. Such colloidal particles may find important applications in a variety of fields including waterborne adhesives, paints, catalysis of chemical reactions, and protein separation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1535–1543, 2009     

Use of polyethylene glycol coatings for optical fibre humidity sensing

Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from a semi-crystalline structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity sensor is discussed.     

Suzuki Cross-Coupling Reaction with Genetically Encoded Fluorosulfates for Fluorogenic Protein Labeling

A palladium-catalyzed cross-coupling reaction with aryl halide functionalities has recently emerged as a valuable tool for protein modification. Herein, a new fluorogenic modification methodology for proteins, with genetically encoded fluorosulfate-l -tyrosine, which exhibits high efficiency and biocompatibility in bacterial cells as well as in aqueous medium, is described. Furthermore, the cross-coupling of 4-cyanophenylboronic acid on green fluorescent protein was shown to possess a unique fluorogenic property, which could open up the possibility of a responsive “off/on” switch with great potential to enable spectroscopic imaging of proteins with minimal background noise. Taken together, a convenient and efficient catalytic system has been developed that may provide broad utilities in protein visualization and live-cell imaging.     

Development and validation of HTS assay for screening the calcium-activated chloride channel modulators in TMEM16A stably expressed CHO cells

Calcium-activated chloride channels (CaCCs), for example TMEM16A, are widely expressed in a variety of tissues and are involved in many important physiological functions. We developed and validated an atomic absorption spectroscopy (AAS)-based detection system for high-throughput screening (HTS) of CaCC modulators. With this assay, Cl^? flux from CHO cells stably transfected with TMEM16A is assayed indirectly, by measuring excess silver ions (Ag⁺) in the supernatant of AgCl precipitates. The screening process involved four steps: (1) TMEM16A CHO cells were incubated in high-K⁺ and high-Cl^? buffer with test compounds, and with ionomycin as Ca²⁺ ionophore, for 12 min; (2) cells were washed with a low-K⁺, Cl^?-free and Ca²⁺-free buffer; (3) CaCC/TMEM16A were activated in high-K⁺, Cl^?-free buffer with ionomycin (10 μmol L^?1) for 12 min; and (4) excess Ag⁺ concentration was measured using an ion channel reader (ICR, an AAS system). The assay can be used to screen CaCC activators and inhibitors at the same time. With this assay, positive control drugs, including NPPB, CaCCinh-A01, flufenamic acid (Flu) and E_act, all had good concentration-dependent effects on CaCC/TMEM16A. NPPB and CaCCinh-A01 inhibited the CaCC/TMEM16A currents completely at 300 μmol L^?1, with IC₅₀ values of 39.35?±?4.72 μmol L^?1 and 6.35?±?0.27 μmol L^?1, respectively; and E_act, activated CaCC/TMEM16A, with an EC₅₀ value of 3.92?±?0.87 μmol L^?1.     

Sulphur transformation during pyrolysis of an Australian lignite

Transformation of various sulphur forms, including inherent and added pyrite, sulphates (CaSO₄ and FeSO₄) and organic sulphur, during pyrolysis of an Australian lignite was studied using TGA, TGA-MS and a fixed bed reactor, supplemented by sulphur form analysis. It was shown that hydrogen sulphide (H₂S) and a small quantity of sulphur dioxide (SO₂) were released during the pyrolysis of the pyrite-lignite blend. However, only SO₂ was detected during the pyrolysis of the lignite with high pyrite content. Inorganic matter was found to help retaining some of the inorganic sulphur, including pyrite, in the char. Inherent sulphates decomposed at much lower temperatures than the added sulphates, releasing SO₂ rather than H₂S. The inherent sulphates in the lignite were dominated by iron sulphates which started to decompose and release SO₂ at around 500 K and all sulphate had been decomposed at 1073 K. The retention of organic sulphur in the high organic sulphur lignite was higher than in its acid washed lignite sample, due to the interaction between inherent inorganic matter with the organic sulphur retaining the organic sulphur in the solid phase. SO₂ was the only sulphur gas produced during pyrolysis of acid washed lignite. A comprehensive mechanism of sulphur transformation during pyrolysis of lignite was proposed.     

Electrochemical capacitive properties of CNT fibers spun from vertically aligned CNT arrays

Due to their lightweight, large surface area; excellent electrical conductivity; and mechanical strength, carbon nanotube (CNT) fibers show great potentials in serving as both electrode materials and current collectors in supercapacitors. In this paper, the capacitive properties of both as-spun CNT fibers and electrochemically activated CNT fibers have been investigated using cyclic voltammetry and electrochemical impedance spectroscopy. It is found that the as-spun CNT fibers exhibit a very low specific capacitance of 2.6 F g⁻¹, but electrochemically activated CNT fibers show considerably improved specific capacitance. The electrochemical activation has been realized by cyclic scanning in a wide potential window. Different electrolytes have also been examined to validate the applicability of our carbon materials and the activation mechanism. It is believed that such an activation process can significantly improve the surface wetting of the CNT fibers by electrolyte (aqueous Na₂SO₄ solution). The cycling stability and rate-dependence of the capacitance have been studied, and the results suggest practical applications of CNT fibers in electrochemical supercapacitors.