Effect of additives on the structure and electrochemical performance of mesoporous nickel hydroxide

Nickel hydroxide mesoporous structures are synthesized by a simple method in the presence of different additives (oxalic acid, aminoacetic acid, and sulfosalicylic acid). Structural characterizations reveal that the additives can affect the crystal structure, increase the specific surface area, and reduce the pore size of the products. The electrochemical properties of the synthesized Ni(OH)₂ samples are dependent on their crystal phase, surface area, and pore size distribution. Mesoporous β-Ni(OH)₂ with poor crystallinity shows high specific capacitances at different current densities and excellent cycling ability. A highest specific capacitance of 1,693 F?g^?1 can be achieved at a scan rate of 5 mV?s^?1. The results suggest its potential application in electrochemical supercapacitors.     

Simultaneous determination of seven lignans in Justicia procumbens by high performance liquid chromatography–photodiode array detection using relative response factors

A simple and sensitive HPLC coupled with photodiode array (HPLC–PDA) method was developed for simultaneous determination of seven lignans in Justicia procumbens using relative response factors (RRFs). The chromatographic separation was performed on a Shiseido Capcell Pak C₁₈ column (250 × 4.6 mm id, 5 μm), a gradient elution of acetonitrile/water, and a photodiode array detector. The column temperature was maintained at 35°C and the detection wavelength was set at 256 nm. Chinensinaphthol methyl ether was selected as the reference compound for calculating the relative response factors of the lignans. It has shown that the RRFs for lignans are quite similar at 256 nm of detection under different analytical conditions (different columns and HPLC instruments). Using RRFs, not every lignan is needed as a reference standard, making the method ideal for rapid, routine analysis, especially for those laboratories where lignans standards are not readily available. An economic and practicable HPLC method using RRFs was established for the determination of seven lignans in J. procumbens. This method not only can determine multiple indexes in traditional Chinese medicines (TCMs) simultaneously, but also resolve the problem of lacking of chemical standards. It will be a good quality evaluation method and pattern for TCMs.     

A novel mesogen‐jacketed liquid crystalline electroluminescent polymer with both thiophene and oxadiazole in conjugated side chain

Mesogen‐jacketed liquid crystalline polymers (MJLCPs) with both electron‐transport oxadiazole and hole‐transport thiophene in the side chain were reported for their promising electroluminescent property. Monomers of 2,5‐bis{5‐[(4‐alkoxyphenyl)‐1,3,4‐oxadiazole]thiophen‐2‐yl}styrene (M‐Cm, m is the number of the carbons in the alkoxy groups, m = 8,10) were synthesized and confirmed by ¹H‐NMR, mass spectrometry, and elemental analysis. The corresponding polymers were successfully obtained and characterized by thermal analysis, optical spectroscopy, cyclic voltammetry, electroluminescent analysis, polarized light microscopy (PLM), and wide‐angle X‐ray diffraction (WAXD). The polymers exhibited high decomposition temperatures reaching 382 °C and high T_g's reaching 184 °C. The absorption spectra indicated that both the monomers and polymers had little aggregation in film than that in solution, and the absorption spectra of the polymers showed an obvious blue‐shift compared with those of the monomers. Both the monomers and the polymers had blue‐green emission, and the photoluminescence spectra of the polymers in film suggested the formation of excimer or exciplex. The polymers showed lower HOMO energy levels and LUMO energy levels than those of the MJLCPs containing oxadiazole unit reported before. Electroluminescence study with the device configuration of ITO/PEDOT/PVK/polymer/TPBI/Ca/Ag showed maximum brightness and current efficiency of 541 cd/m² and 0.10 cd/A, which proved that the introduction of directly connected electron‐ and hole‐transport units could greatly improve the EL property of side‐chain conjugated polymers. The phase structures of the polymers were confirmed to be smectic A phase through the results of PLM and WAXD. The annealed samples emitted polarized photoluminescence at room temperature, which indicated potential utility for practical applications in display. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1502–1515, 2010     

Expression and Emmprin Regulated Function of Aquaporinl in SMMC7221 Cells

<正>Herein lie the crosstalk and regulation between AQP1 and Emmprin in SMMC7221 cells by means of siRNA technology and deglycosylation method.Firstly,HAQP1,rather than hAQP3,was selectively upregulated in SMMC7221 cells by FBS,flollowed by the upregulated expression of Emmprin.Emmprin gene silencing caused a remarkable change in the expression of AQP1 gene,just like its downstream gene,MMP9,meanwhile the water permeability and cell migration were also descended prominently.Furthermore,when treated with tunicamycin, Emmprin was deglycosylated,which made the expression of AQP1 significantly declined,followed by remarkably decreased cell membrane water permeability and cell migration.Taken together,all the data indicates the expression level and the modification of Emmprin by glycosylation are the key factors in regulating the expression of AQP1.     

Theory of Microbial Carbonate Precipitation and Its Application in Restoration of Cement-based Materials Defects

Bacterial induced carbonate mineralization has been demonstrated as a new potential method for restoration of limestones in historic buildings and monuments. We claim here the formation of calcium carbonate was controlled by extracellular polymeric substances (EPS) isolated from Bacillus pasteurii. The process of crystallization nucleation was accelerated in the presence of cells and inhibited in the presence of EPS. The CaCO₃ film deposited on cement paste surface was about 100 µm after 7 d treatment. The results of various restoring methods showed that higher decrease of water absorption of cement paste was gained in brushing application in the presence of agar, which could maintain urease with high activity in long term compared to spraying method. The coefficient of capillary suction of cement paste treated with brushing method was reduced by 90%. Mixed media consisted of sands, urea, Ca²⁺ and concentrated biomass, was injected into artificial cracks of cement paste followed by continual nutrient supplement, and CaCO₃ particles were precipitated gradually between sands particles which were combined with cement matrix. The results showed that the compressive strength of recovered specimens was restored to 84%, which demonstrated that this kind of bio‐restoration method is effective in repairing surface defects of cement‐based materials.     

Effect of the Si/Ce molar ratio on the textural properties of rare earth element cerium incorporated mesoporous molecular sieves obtained room temperature

Rare earth Ce-incorporated MCM-41 mesoporous molecular sieves (CeMCM-41) were synthesized via a direct and nonhydrothermal method at room temperature from sodium silicate and ammonium cerium (IV) nitrate as raw materials. Cetyltrimethyl ammonium bromide (CTAB) was used as a template. The resultant samples were characterized by means of powder X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance ultraviolet–visible spectroscopy (UV–vis) and N₂ physical adsorption, respectively. The effect of the Si/Ce molar ratio on the crystalline structure and textural properties of CeMCM-41 was also investigated. The experimental results show that ordered CeMCM-41 mesoporous molecular sieves were successfully synthesized at room temperature and the resultant mesoporous materials have specific surface areas in the range of 594–1369 m²/g and average pore sizes in the range of ca. 2.5–2.8 nm. It has been found that the structural properties are strongly related to the amounts of cerium incorporation. When the cerium content increased in the samples, the intensity of the peak (1 0 0) was gradually reduced, and the surface area and structural regularity were diminished.