毛细管电泳Ru(bpy)_3~(2+)电化学发光的研究进展

本文简要介绍了毛细管电泳Ru(bpy)32+电化学发光的基本特性,概述了其在与复合材料和微控芯片结合应用时的研究进展,就近几年来的报道,综述了毛细管电泳Ru(bpy)32+电化学发光在药物分析,食品分析,生命科学领域的应用,并对毛细管电泳Ru(bpy)32+电化学发光的前景进行了展望.     

Syntheses of linear ethoxysiloxanes by the oxidative condensation of triethoxysilane

Linear ethoxysiloxanes were synthesized by the oxidative condensation of hydrosilane. Triethoxysilane was subjected to oxidation to form triethoxysilanol, and pentaethoxydisiloxane was formed by the condensation reaction of triethoxysilane with triethoxysilanol. Pentaethoxydisiloxane was also subjected to oxidative condensation to form a mixture of nona- and decaethoxytetrasiloxanes. In contrast, pentaethoxydisiloxane, heptaethoxytrisiloxane, and nonaethoxytetrasiloxanes were subjected to the reaction with ethanol in the presence of zinc to isolate hexaethoxydisiloxane, octaethoxytrisiloxane, and decaethoxytetrasiloxane, respectively.     

Degradation of physicomechanical properties of epoxy nanocomposites with carbon nanotubes upon heat and humidity aging

The dependence of the physicomechanical properties of epoxy nanocomposites subjected to heat and humidity aging on the type of covalently functionalized carbon nanotubes and on the uniformity of their distribution in the epoxy matrix was studied. Two types of carbon nanotubes were used: those modified with carboxy and amide groups. The elastic modulus, bending deflection, and ultimate bending strength for the initial epoxy nanocomposites with carbon nanotubes and for those subjected to heat and humidity aging were determined. The epoxy binders modified with carboxylated carbon nanotubes are more resistant to the action of aging factors. The presence of aggregates of carboxylated carbon nanotubes in the epoxy matrix positively influences the preservation of physicomechanical properties of the composite subjected to heat and humidity aging. Microscopic examination revealed structural features of the epoxy nanocomposite and their effect on the resistance of the composite to the heat and humidity aging.     

Kinetic models for the SR1500 and LY556 epoxies under manufacturer’s recommended cure cycles

The kinetic behaviours of two commercial epoxy resin systems subjected to manufacturer’s recommended cure cycles (MRCC) were studied in detail. The two systems were characterized through differential scanning calorimetry (DSC) using both isothermal and dynamic test conditions. The kinetic parameters were determined and two original kinetic models were established for these resin systems subjected to the “real” processing conditions. In this paper the experimental procedure is described, together with its results and the original kinetic models developed.     

Determination of Macro, Micro and Ultra Micro Concentration of Some Elements in Normal and Diseased Tissues of the Bone by NAA Employing 252Cf and Reactor Neutrons

A method has been developed for the determination of elements in normal and diseased tissues of the bone employing radiochemical and instrumental neutron activation analysis. Elements such as Na, Br, Au, Sb, Sc, Fe, Zn and Cr were subjected to irradiation in ²⁵²Cf or CIRUS reactor followed by measurement of the activity on a HPGe detector coupled to a PC based MCA unit. Elements such as Co, Ca and P were subjected to radiochemical separation prior to the measurement. The statistical evaluation with respect to accuracy and precision is discussed.     

Synthesis of ionic block polymers for desalination membranes

Copolymer containing 2-vinylpyridine–trimethylsilyl methacrylate, styrene–2-vinylpyridine, and styrene–trimethylsilyl methacrylate blocks as well as terpolymers containing the styrene2–vinylpyridine–trimethylsilyl methacrylate blocks were synthesized by initiation of the appropriate monomers sequentially both with butyllithium and sodium. These polymers were subjected to hydrolysis by which the acrylate ester segment is converted to the free acid and to the reaction with methyl iodide, which quaternizes the pyridine segment; finally the hydrolyzed and quaternized polymers were subjected to dehydrohalogenation with external base. The properties of these block polymers and blends of the styrene-containing block copolymers were examined, especially in regard to their suitability as reverse osmosis desalination membranes.     

Evaluation of the physiologically based extraction test as an indicator of metal toxicity in mussel tissue

In order to estimate the bioaccessibility of metals from mussel tissues, an in vitro physiologically based extraction test was applied to simulate the human gastrointestinal conditions. The samples were subjected to human body temperature, and Ag, Co, Cr, Cu, Mn, Ni, Pb and Sn were sequentially extracted with simulated gastric solution, followed by extraction with a simulated intestinal solution. Both gastric and intestinal extracted solutions and microwave-digested residue were analysed by ICP-MS. The procedure was applied to a certified reference material NIST 2977 (mussel tissue) to prove the accuracy of the method. Some mussel tissue samples from Northern Spain were subjected to this procedure to determine their metal content and their metal oral bioaccessibility.     

Thermal degradation of lignins isolated from wood

The lignin preparations isolated from pine and beech wood were subjected to a thermogravimetric analysis (TG). The lignin preparations were also used to obtain samples of different degrees of thermal degradation characterised by mass-losses in the interval from 10 to 60% of their initial mass. These samples were subjected to elementary analysis and the content of methoxy groups. It was observed that the content of these functional groups declined in products in which the degree of thermal degradation exceeded 30%, which corresponds to temperatures over 450°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermally-Polymerized Rylene Nanoparticles

Rylene dyes functionalized with varying numbers of phenyl trifluorovinylether (TFVE) moieties were subjected to a thermal emulsion polymerization to yield shape-persistent, water-soluble chromophore nanoparticles. Perylene and terrylene diimide derivatives containing either two or four phenyl TFVE functional groups were synthesized and subjected to thermal emulsion polymerization in tetraglyme. Dynamic light scattering measurements indicated that particles with sizes ranging from 70 - 100 nm were obtained in tetraglyme, depending on monomer concentration. The photophysical properties of individual monomers were preserved in the nanoemulsions and emission colors could be tuned between yellow, orange, red, and deep red. The nanoparticles were found to retain their shape upon dissolution into water and the resulting water suspensions displayed moderate to high fluorescence quantum yield.     

Indentation of poly(methyl methacrylate) under high‐pressure gases

The variation of the indentation hardness of a high molecular weight poly(methyl methacrylate) (PMMA) subjected to CO₂ and Ar at high pressure was measured in situ. The samples were subjected to gas exposure for 3 h at 40 °C before a conical indenter of an included angle at 105 °, with a fixed load of 0.237 kg, was applied for a loading time of 60 s. The data show that both CO₂ and Ar reduce the hardness of PMMA to a comparable extent at low pressures. The hardness of PMMA subjected to Ar indicates a minimum at about 4 MPa and then increases. CO₂ produced a monotone decreasing trend in hardness in the pressure range studied, and the glass‐transition temperature (T_g) was achieved at about 6.0 MPa. The change in hardness is attributed to plasticization of the polymer matrix that is more extensive for CO₂. The relationship between the change in hardness for this PMMA subjected to high‐pressure CO₂, the corresponding change in the T_g, and the associated swelling of the polymer is discussed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 3020–3028, 2001     

Beitrag zur Synthese von Tetracenchinonen

1,4-Dihydroxyanthraquinones are transformed into the corresponding chlorohydroxy-ana-anthraquinone dienophiles, which are subjected to Diels-Alder addition with 1,3-dienes. The adducts formed are dehydrogenated to known and to new hydroxynaphthacene quinones.     

Adsorption of dyes on carbon xerogels and templated carbons: influence of surface chemistry

The removal of textile dyes by adsorption onto carbon materials with extended mesoporosity is addressed in the present work. Two types of high surface area carbon adsorbents were prepared, namely a carbon xerogel and a templated carbon. Both materials were subsequently subjected to appropriate treatments in order to modify their surface chemistries, while keeping their textural properties relatively unchanged. The carbon adsorbents were extensively characterized by different techniques in order to correlate their adsorption performances with the corresponding surface properties. The behavior of the different materials was evaluated by determining equilibrium adsorption isotherms of two anionic dyes (Reactive Red 241 and Acid Blue 113) at different pH values. The results are compared with data previously obtained with commercial activated carbons subjected to the same treatments, and discussed in terms of the carbon surface chemistry and the interaction between the dye molecules and the adsorbent surface (dispersive and electrostatic interactions).     

Enzymatic hydrolysis of collagen by pancreatin and thrombin as a step in the formation of scaffolds

Russian Chemical Bulletin - High-molecular collagen was isolated from cod skin and subjected to enzymatic hydrolysis with pancreatin and thrombin. The resulting products were characterized by...     

Syntheses of (-)-TAN-2483A, (-)-massarilactone B, and the fusidilactone B ring system. Revision of the structures of and syntheses of (+/-)-Waol A (FD-211) and (+/-)-Waol B (FD-212)

The structure of waol A has been revised from 1 to 6, the vinylogue of TAN-2483A (5). Aldol reaction of hydroxybutanolides 13b,c with 2,4-hexadienal affords 12b,c, which are subjected to iodoetherification with bis(sym-collidine)IPF6 to provide 11b(c). Treatment with Et3N in CH2Cl2 completes the three-step syntheses of TAN-2483A (5) and waol A (6). Aldol reaction of hydroxybutanolide 31 with 2,4-hexadienal affords 32, which is subjected to iodoetherification to provide 34, which in turn is treated with Bu3SnCl, NaBH3CN, and oxygen to provide diol 60. Further elaboration completes the first syntheses of massarilactone B (7) and the fusidilactone B (9) ring system.     

Processing of cyclopropylarenes by toluene dioxygenase: isolation and absolute configuration of metabolites

Several arenes possessing a cyclopropyl substituent were subjected to enzymatic oxidation with toluene dioxygenase. The absolute configuration of metabolites was established by chemical means.     

Phosphorylation of 3',4',5,7-Tetramethyldihydroquercetin

3',4',5,7-Tetramethyldihydroquercetin was phosphorylated with phosphorous acid derivatives, and similar results were obtained with phosphorochloridites and phosphoramidites. The PIII derivatives obtained were subjected to oxidation. The structures of the products were determined by NMR spectroscopy.     

Preparation de membranes mosaiques par greffage radiochimique dans des films de polytetrafluoroethylene

Mosaic membranes were prepared by two successive grafting steps of acrylic acid and 4-vinyl-pyridine into well localized domains of polytetrafluoroethylene films. The films were subjected to X-rays through a grid-shaped shield which activated linear zones of the film 0.5 mm wide, separated by 0.5 mm of unactivated film. The films were then grafted with acrylic acid, neutralized and subjected to a second irradiation through a shield which protected the grafted zones. 4-Vinylpyridine was then grafted into the stripes left unchanged after the first treatment. The following properties of the resulting mosaic membranes were examined: swelling in water, electric conductivity and ion-pair diffusion. The coefficients of ion-pair diffusion were found to be 100–1000 times higher for the mosaic membranes than for carboxylic membranes of the same grafting ratio.     

Synthesis of a new class of glycolipids and the evaluation of their immunogenicity using murine splenocytes

A new class of glycolipids were generated by the incorporation of lipid entities at the C-6 position of D-glucose through oxidation of the primary hydroxyl group of tetrabenzylated D-glucose to form corresponding aldehyde, which in turn was subjected to Grignard reaction with C8 and C16 alkyl magnesium halides. The resulting lipidated secondary alcohol was further subjected to esterification with long-chain carboxylic acids to afford novel glycolipids. All of the derivatives 4a–b, 6a–d, and 8a–b exhibited low cytotoxicity and induced strong T and B cell proliferation and IL-2, IL-4, and IFN-γ expression from stimulated splenocyte culture, signifying their potent immunostimulating activity.     

6-(2-Haloethyl)-2,2-dimethyl-4H-1,3-dioxins: versatile haloethyl vinyl ketone equivalents for carbocycle construction

6-(2-Iodoethyl)-2,2-dimethyl-4H-1,3-dioxin has been prepared in five steps from ethyl acetoacetate. A variety of enolates were then alkylated with this iodide. The resulting 6-alkyl-4H-1,3-dioxins were either subjected to further transformations and/or heated (or subjected to a Lewis acid) to effect facile retrocycloaddition reactions. The resulting enones were found to smoothly participate in conjugate addition or olefin metathesis reactions to provide various carbocyclic ring systems. Collectively, these examples document the synthetic equivalency of dioxin 2 with iodoethyl vinyl ketone and, moreover, delineate a strategy for accomplishing the sequential reactions with nucleophiles at the β′, followed by the β electrophilic sites.     

Evolution of coercivity and its angular dependence in CoFe nanostructures subjected to field cooling

Evolution of coercivity and its angular dependence in CoFe nanostructures subjected to field cooling has been investigated in this work. Spherical CoFe grains with an average diameter of 30 nm were grown on a silicon substrate using electron beam evaporation. Further, the as‐deposited sample was subjected to field cooling. The morphology and topography of the sample before and after field cooling were characterized by atomic force microscopy and SEM. Magnetic force microscopy indicated that there is a good uniformity of magnetization throughout the sample after field cooling. Vibrating sample magnetometer measurements indicate that the coercivity in CoFe nanostructures is dependent on shape of the nanostructures. Copyright © 2013 John Wiley & Sons, Ltd.