双酰胺类衍生物的合成及抑菌活性

以对氯苯甲酸和取代邻氨基苯甲酸为起始原料,设计并合成9个未见文献报道的含苯并噻唑基双酰胺类化合物,其结构经1H NMR、13C NMR、IR及元素分析确证。初步生物活性测试结果表明,部份化合物具有一定的抑菌活性。     

The electronic spectrum of Si3 I: triplet D(3h) system

We report the measurement of a jet-cooled electronic spectrum of the silicon trimer. Si(3) was produced in a pulsed discharge of silane in argon, and the excitation spectrum examined in the 18 000-20 800 cm(-1) region. A combination of resonant two-color two-photon ionization (R2C2PI) time-of-flight mass spectroscopy, laser-induced fluorescence/dispersed fluorescence, and equation-of-motion coupled-cluster calculations have been used to establish that the observed spectrum is dominated by the 1(3)A(1)" - a? (3)A(2)' transition of the D(3h) isomer. The spectrum has an origin transition at 18,600 ± 4 cm(-1) and a short progression in the symmetric stretch with a frequency of ～445 cm(-1), in good agreement with a predicted vertical transition energy of 2.34 eV for excitation to the 1(3)A(1)" state, which has a calculated symmetric stretching frequency of 480 cm(-1). In addition, a ～505 cm(-1) ground state vibrational frequency determined from sequence bands and dispersed fluorescence is in agreement with an earlier zero-electron kinetic energy study of the lowest D(3h) state and with theory. A weaker, overlapping band system with a ～360 cm(-1) progression, observed in the same mass channel (m/z = 84) by R2C2PI but under different discharge conditions, is thought to be due to transitions from the (more complicated) singlet C(2v) ground state ((1)A(1)) state of Si(3). Evidence of emission to this latter state in the triplet dispersed fluorescence spectra suggests extensive mixing in the excited triplet and singlet manifolds. Prospects for further spectroscopic characterization of the singlet system and direct measurement of the energy separation between the lowest singlet and triplet states are discussed.     

Bionanoparticles of amphiphilic copolymers polyacrylate bearing cholesterol and ascorbate for drug delivery

In this study, a series of amphiphilic polymers with poly(ascorbyl acrylate) (PAAA) as hydrophilic blocks and polyacrylate bearing side-chain cholesteryl mesogens (PCholDEGA) as hydrophobic blocks were prepared using a combination of four-step reactions consisting of two consecutive reversible addition-fragmentation chain transfer (RAFT), desulfurization, and hydrogenolysis under normal pressure. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) as well as wide-angle X-ray diffraction (WAXD) studies showed that the copolymers with PCholDEGA as major block had relatively high stability and clear isotropization temperature (T(i)). Small-angle X-ray diffraction (SAXD) investigation exhibited that the copolymers had bilayer smectic A structure. Their self-assembly behavior was monitored by turbidity change using UV-vis spectrometer, and the morphology and size of the nanoparticles via self-assembly were detected using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The entrapment efficiency and loading capacity of these amphiphilic copolymers were investigated using nile red and drug molecule Ibuprofen. These polymeric micelles with PAAA shell extending into the aqueous solution and strong hydrophobic PCholDEGA core have potential abilities to act as promising nanovehicles with high loading and targeting delivery.     

Enzyme-catalyzed silver deposition on irregular-shaped gold nanoparticles for electrochemical immunoassay of alpha-fetoprotein

A new and disposable electrochemical immunosensor was designed for detection of alpha-fetoprotein (AFP), as a model analyte, with sensitivity enhancement based on enzyme-catalyzed silver deposition onto irregular-shaped gold nanoparticles (ISGNPs). The assay was carried out with a sandwich-type immunoassay protocol by using ISGNP-labeled anti-AFP antibodies conjugated with alkaline phosphatase (ALP–Ab₂) as detection antibodies. The enzymatically catalytic deposition of silver on the electrode could be measured by stripping analysis in KCl solution due to the Ag/AgCl solid-state voltammetric process. Several labeling protocols including spherical gold nanoparticle-labeled ALP–Ab₂ and ISGNP-labeled ALP–Ab₂ were investigated for determination of AFP, and improved analytical properties were achieved with the ISGNP labeling. With the ISGNP labeling method, the effects of incubation time and incubation temperature for antigen-antibody reaction, and deposition time of silver on the current responses of the electrochemical immunosensors were also monitored. Under optimal conditions, the electrochemical immunosensor exhibited a wide dynamic range from 0.01 ng mL⁻¹ to 200 ng mL⁻¹ with a detection limit of 5.0 pg mL⁻¹ AFP. The immunosensor displayed a good stability and acceptable reproducibility and accuracy. No significant differences at the 95% confidence level were encountered in the analysis of 10 clinical serum samples between the developed immunoassay and the commercially available electrochemiluminescent method for determination of AFP.     

Novel fluoropolymer anion exchange membranes for alkaline direct methanol fuel cells

A series of novel fluoropolymer anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate, and hexafluorobutyl methacrylate has been prepared. Fourier transform infrared (FT-IR) spectroscopy and elemental analysis techniques are used to study the chemical structure and chemical composition of the membranes. The water uptake, ion-exchange capacity (IEC), conductivity, methanol permeability, and chemical stability of the membranes are also determined. The membranes exhibit high anionic conductivity in deionized water at 65 °C ranging from 3.86×10(-2) S cm(-1) to 4.36×10(-2) S cm(-1). The methanol permeability coefficients of the membranes are in the range of 4.21-5.80×10(-8) cm(2) s(-1) at 65 °C. The novel membranes also show good chemical and thermal stability. An open-circuit voltage of 0.7 V and a maximum power density of 53.2 mW cm(-2) of alkaline direct methanol fuel cell (ADMFC) with the membrane C, 1 M methanol, 1 M NaOH, and humidified oxygen are achieved at 65 °C. Therefore, these membranes have great potential for applications in fuel cell systems.     

气相色谱-质谱法同时测定化妆品中19种邻苯二甲酸酯

建立了同时测定化妆品中19种邻苯二甲酸酯的气相色谱-质谱(GC-MS)方法。样品经二氯甲烷超声提取后,用硅胶-中性氧化铝(2:3, m/m)混合填料固相小柱保留、乙酸乙酯-正己烷(8:2, v/v)洗脱等步骤净化后,采用GC-MS对19种目标物进行定性、定量分析。采用保留时间与特征离子丰度比共同进行定性分析,减少了复杂样品基质中的干扰。在优化的实验条件及0.1、0.5、2.0 μg/g的添加水平下,平均加标回收率为72.2%～110.9%,其中加标水平为0.1 μg/g的相对标准偏差(RSD, n=6)小于10.3%;方法检出限(以3倍标准偏差计)为0.0065 μg/g(邻苯二甲酸二异戊酯)～0.062 μg/g(邻苯二甲酸二异丁酯)之间。应用该方法检测了6种化妆品中19种PAEs的含量。该方法可推广用于多种类型化妆品中PAEs的测定。     

Development and Characterization of EST-SSR Markers from <em>Scapharca broughtonii</em> and Their Transferability in <em>Scapharca subcrenata</em> and <em>Tegillarca granosa</em>

Twenty-five novel EST-derived simple sequence repeat (EST-SSR) markers were developed in the ark shell Scapharca broughtonii. Polymorphisms of these EST-SSR markers were evaluated in 48 wild individuals collected from Shidao, Shandong Province, China. A total of 202 alleles were detected at 25 loci. The numbers of alleles per locus ranged from 4 to 14, with an average of 8.08. The observed and expected heterozygosities varied from 0.2917 to 1.000 and from 0.3570 to 0.9002, respectively. After sequential Bonferroni correction for multiple tests, only one locus was found to deviate from Hardy-Weinberg equilibrium. Twenty-five EST-SSR markers showed a high rate of across-species transferability (100%) in Scapharca subcrenata and a low rate of across-genus transferability (20%) in Tegillarca granosa. These EST-SSRs will be helpful for QTL mapping, molecular breeding and investigation of population genetic diversity in ark shell S. broughtonii and other Scapharca species.     

Polymer micelle-directed growth of BaCO(3) spiral nanobelts

We discovered that micelles of a thermo-responsive polypeptide-based copolymer are able to direct growth of barium carbonate (BaCO(3)) in the form of nanobelts. The BaCO(3) nanobelts tend to grow around a formed crystal, and curl into a spiral superstructure.     

Multicolor super-resolution fluorescence imaging via multi-parameter fluorophore detection

Understanding the complexity of the cellular environment will benefit from the ability to unambiguously resolve multiple cellular components, simultaneously and with nanometer-scale spatial resolution. Multicolor super-resolution fluorescence microscopy techniques have been developed to achieve this goal, yet challenges remain in terms of the number of targets that can be simultaneously imaged and the crosstalk between color channels. Herein, we demonstrate multicolor stochastic optical reconstruction microscopy (STORM) based on a multi-parameter detection strategy, which uses both the fluorescence activation wavelength and the emission color to discriminate between photo-activatable fluorescent probes. First, we obtained two-color super-resolution images using the near-infrared cyanine dye Alexa 750 in conjunction with a red cyanine dye Alexa 647, and quantified color crosstalk levels and image registration accuracy. Combinatorial pairing of these two switchable dyes with fluorophores which enhance photo-activation enabled multi-parameter detection of six different probes. Using this approach, we obtained six-color super-resolution fluorescence images of a model sample. The combination of multiple fluorescence detection parameters for improved fluorophore discrimination promises to substantially enhance our ability to visualize multiple cellular targets with sub-diffraction-limit resolution.     

Ionic conductivity of pure water in charged porous matrix

It is commonly recognized that the ionic conductivity of pure water is very poor because of very low ionic concentrations. However, this work indicates that pure water in charged porous matrixes can be moderately conductive because of the ions in the electric double layer established at the solid/water interfaces. The ionic conductivity of pure water in a charged matrix changes with the electrode potential of the matrix and is influenced by the structural parameters. Both experimental measurements and theoretical calculations reveal that ionic conductivity may reach the order of 10(-3) S cm(-1) in commonly accessible potential region in a porous matrix made of gold nanoparticles. These results would help to understand and optimize the electrode processes in electrochemical devices without deliberately added electrolytes, such as polymer electrolyte membrane fuel cells.