Effect of the luminol signal enhancer on the chemiluminescence intensity and kinetics

The novel p-phenol derivatives, 4-(1-imidazolyl)-phenol, 4-hydroxybiphenyl, 4-hydroxy-4′-iodobiphenyl were employed as highly potent signal enhancers of luminol-hydrogen peroxide (H₂O₂)-horseradish peroxidase (HRP) chemiluminescence (CL) system. The CL reaction conditions were optimized, and the enhancement characteristics of these enhancers were compared with each other. The employment of these molecules greatly affected important assay parameters. Practically, the use of a novel enhancer, even a slightly change of the structure (or concentration) of 4-substituted phenol derivative, could affect assay properties quite dramatically. Furthermore, the use of different enhancers in the luminol–H₂O₂–HRP system can affect not only the intensity of the CL signal, which is well known, but also its kinetics. The experiment data indicated that the stronger intensity was combined with a more rapid decrease of the CL signal.     

Biocompatible poly(ethylene glycol)‐poly(γ‐cholesterol‐L‐glutamate) copolymers: Synthesis,characterization, and in vitro studies

A novel amphiphilic poly(ethylene glycol)‐block‐poly(γ‐cholesterol‐L ‐glutamate) (mPEG–PCHLG) diblock copolymer has been synthesized. The mPEG–PCHLG copolymer has good biocompatibility and low toxicity. The mPEG–PCHLG copolymers could aggregate into nanoparticles with PCHLG blocks as the hydrophobic core and PEG blocks as the hydrophilic shell through emulsion solvent evaporation method. The copolymers were characterized by nuclear magnetic resonance spectroscopy, mass spectrum, Fourier transform infrared spectroscopy, and gel permeation chromatography. The particle sizes, size distributions, and zeta potentials of nanoparticles can also be determined by dynamic light scattering and transmission electron microscopy. This work provides a new and facile approach to prepare amphiphilic block copolymer nanoparticles with controllable performances. This novel copolymer may have potential applications in drug delivery and bioimaging applications.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines

A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl‐hydrazide‐catalyzed asymmetric OH‐substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]₂, 4 mol % (S)‐SegPhos, and 10 mol % 2,5‐dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.     

A physical mechanism based investigation on the elasto-plastic-damage behavior of anisotropic aluminum alloys under finite deformation

The elasto-plastic-damage behavior of anisotropic aluminum alloys is investigated under finite deformation using a physical mechanism based constitutive model. With an application to the structural calculation, the present model is used to describe and analyze the mechanical response of anisotropic 6260-T6 aluminum alloy extrusions. For the tensile specimens extracted along three different material orientations from the extruded aluminum profile, twelve simulations are carried out covering four different specimen geometries. The simulation results in force-displacement response and central logarithmic axial strain evolution are compared with experimental results. From the comparisons, it can be concluded that the present model has the capacity to describe the behavior of anisotropic material. From the force-displacement curves, the anisotropy is observed in different material orientations, and the physical mechanism of anisotropy is analyzed.     

高能反应机制与自旋效应

高能强子一强子反应实验中发现一系列引人注目的自旋效应,这些效应出现的机理一直是人们关注的热门课题之一.近几年,在实验及理论家共同的努力下,虽仍有许多不清楚的问题,但已取得一些突破.结果表明,不仅对这些现象产生机理研究能为强子结构及强子反应机制提供信息,而且这些现象本身也用作探索强子反应机制的工具.例如用它们来研究小x_B光子与强子反应的性质.本报告将首先简单总结这些现象及其产生机理研究的结论,然后介绍该例的主要思想及结果.     

An improved optimization strategy and its application to clustering analysis.

In this paper, a new optimization strategy is put forward which locates as many potential unimodal regions as possible in the search space. The potential optima can be further explored by a global optimization method for searching in the identified unimodal regions. The proposed strategy was evaluated by the optimization of test functions. The results obtained by this approach are comparable with those achieved by variable step size generalized simulated annealing (VSGSA) and a genetic algorithm (GA). Finally, we used this strategy in a clustering analysis of a tobacco data set.     

Wigner function for the generalized excited pair coherent state

This paper introduces the generalized excited pair coherent state （GEPCS）. Using the entangled state 〈η〉 representation of Wigner operator, it obtains the Wigner function for the GEPCS. In the ρ-γ phase space, the variations of the Wigner function distributions with the parameters q, α, k and l are discussed. The tomogram of the GEPCS is calculated with the help of the Radon transform between the Wigner operator and the projection operator of the entangled state ｜η1, η2, τ1, τ2｜. The entangled states ｜η〉 and ｜η1, η2, τ1, τ2〉 provide two good representative space for studying the Wigner functions and tomograms of various two-mode correlated quantum states.