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901.
CHENG SIQING MENG XIANGGUANG CHEN YONG WANG QIAN ZENG XIANCHENG 《Journal of Dispersion Science and Technology》2013,34(2):199-207
The effect of Fe (II) metallomicelle as a model of catalase, which was formed by adding surfactants (CTAB, SDS, LSS, Brij35) in Fe (II) -trien complex of molar ratios 1: 500 on the decomposition of hydrogen peroxide was investigated at 20°C and 30°C in pH 10 using KI-color and UV Spectrophotometry. A kinetic model for metallomicellar catalysis was proposed. The association constant of the ternary complex K and the rate constant of the decomposition of hydrogen peroxide k3 were obtained. The results indicate that the metallomicelles making up of Fe (II) metal complex and cationic or nonionic surfactants have obvious catalysis on the decomposition of hydrogen peroxide, but the metallomicelles making up of Fe (II) metal complex and anionic or zwitterionic surfactants have inhibition on this reaction. 相似文献
902.
XIANG VAN ZENG XIANCHENG∗ CHENG SIQING LI YANTUAN XIE JIAQING 《Journal of Dispersion Science and Technology》2013,34(7):857-867
Abstract The hydrolysis of p-nirrophenyl picolinate (PNPP) catalyzed by the Cu(II) and Zn(H) complexes of d-glucosamine schiff base was investigated kinetically by observing the rates of the release of p-nitrophenol in the buffered micellor solution at different pit and 25°C. The scheme for reaction acting mode involving a ternary complex contain ligand, metal ion and substrate in micelle was establish and the reaction mechanisms were discussed The experimental results indicated that the complexes catalyzed efficiently the hydrolysis of PNPP, especially Zn(II) complex. The rate constant kN, which shows the catalytic reactivity of complexes, WBI determined to be 0.4251 s?1 far Cu(II) complex at pH 7 60 in micellar solution. The catalytic reactivity of Zn(II) complex were much larger than Cu(II) complex, the kN was determined to be 3.1914 s?1 at same pH value. 相似文献
903.
Bin Xie Xue‐Song Feng Chun‐Xiao Zhang Xian‐Cheng Zeng 《Journal of Dispersion Science and Technology》2013,34(6):920-926
Two Schiff base transitional metal complexes bearing morpholine side chains were synthesized and characterized, and were used as a simulative hydrolase in the catalytic hydrolysis of p‐nitrophenyl picolinate (PNPP) in this article. A mechanism of PNPP catalytic hydrolysis in the Brij35 micellar solution was proposed and supported by the results of the spectral analysis and the kinetic calculation. The kinetic model of PNPP catalytic hydrolysis was studied. The some kinetic and the thermodynamic constants on the catalytic reaction were calculated. The results of the study show that the metallomicelle made up of the Schiff base transitional metal complexes and Brij35 micelle revealed a good catalytic activity in PNPP catalytic hydrolysis; the rate of the PNPP catalytic hydrolysis is increased following the increase of the pH values in the buffer solution and affected by the polarization action of metal ion of complex. 相似文献
904.
在线质谱仪检测植物排放的挥发性有机物 总被引:2,自引:0,他引:2
利用在线检测质谱仪(SPIMS-1000)分别对高温烘烤、长时间密封保存、机械损伤等处理过的松科松属马尾松(Pinus Massoniana L.)样品排放的挥发性有机物(VOCs)与新鲜样品进行对比检测。SPIMS-1000在线检测质谱仪能够检测出植物排放的异戊二烯(m/z 68)和单萜(m/z 136),及其它一些特异性组分,如(Z)-3-己烯醛(m/z 98)等。利用在线检测质谱仪实现敞开环境中原位植物排放气体的检测。实验表明,在线检测质谱仪被广泛应用于环境中VOCs的实时、在线、定性快速检测。 相似文献
905.
<正>The C-Br bond of 2-bromothiophene was successfully cleavaged by tetrakis(trimethylphosphine)cobalt(0). Penta-coordinate cobalt(II) bromide complex 1 (α-C_4H_3S)CoBr(PMe_3)_3 as C-Br bond activation product was obtained. The molecular and crystal structures of complex 1 were determined by single-crystal X-ray diffraction. Complex 1 belongs to the orthorhombic crystal system, space group Pnma with a = 20.428(4) , b =11.036(2) , c = 9.201(2), V = 2074.3(7)~3, Z = 4, D_c = 1.442 g/cm~3, μ = 0.401 mm~(-1), F(000) = 924 and T = 273 K. Complex 1 was also characterized by elemental analysis, IR, UV-Vis, photoluminescence (PL) spectroscopy and TGA. 相似文献
906.
Xiao‐Zhi He Bao‐Yan Zhang Corresponding author Jian‐She Hu Mei Tian 《Liquid crystals》2013,40(3):299-306
In this work we prepared a nematic monomer (4′‐allyloxybiphenyl 4′‐ethoxybenzoate, M1 ), a chiral crosslinking agent (isosorbide 4‐allyloxybenzoyl bisate, M2 ) and a series of new side chain cholesteric liquid crystalline elastomers derived from M1 and M2 . The chemical structures of the monomers and polymers were confirmed by FTIR and 1H NMR spectroscopy. The mesomorphic properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy and X‐ray diffraction. The effect of the content of the crosslinking unit on phase behaviour of the elastomers is discussed. Polymer P1 showed a nematic phase, P2 –P7 showed a cholesteric phase; P6 formed a blue Grandjean texture over a broad temperature range 145–209.6°C, with no changed on the cooling. Polymers P4 –P7 , with more than 6?mol?% of chiral crosslinking agent, gave rise to selective reflection. Elastomers containing less than 15?mol?% of the crosslinking units displayed elasticity, reversible phase transition with wide mesophase temperature ranges, and high thermal stability. Experimental results demonstrated that, with increasing content of crosslinking agent, the glass transition temperatures first fell and then increased; the isotropization temperatures and mesophase temperature ranges decreased. 相似文献
907.
Wei Deng Hefang Xiao Xiangfu Zeng Yiping Hu 《Applied biochemistry and biotechnology》2013,169(2):450-461
A novel vector with high gene delivery efficiency and special cell targeting ability was developed using a good strategy that utilized low molecular weight polyethylenimine (PEI; molecular weight, 600 KDa [PEI600]) cross-linked to β-cyclodextrin (β-CyD) via a facile synthetic route. Human epidermal growth factor receptor 2 (Her-2) are highly expressed in a variety of human cancer cells and are potential targets for cancer therapy. MC8 peptides, which have been proven to combine especially with Her-2 on cell membranes were coupled to PEI-β-CyD using N-succinimidyl-3-(2-pyridyldithio) propionate as a linker. The ratios of PEI600, β-CyD, and peptide were calculated based on proton integral values obtained from the 1H-NMR spectra of the resulting products. Electron microscope observations showed that MC8-PEI-β-CyD can efficiently condense plasmid DNA (pDNA) into nanoparticles of about 200 nm, and MTT assays suggested the decreased toxicity of the polymer. Experiments on gene delivery efficiency in vitro showed that MC8-PEI-β-CyD/pDNA polyplexes had significantly greater transgene activities than PEI-β-CyD/pDNA in the Skov3 and A549 cells, which positively expressed Her-2, whereas, no such effect was observed in the MCF-7 cells, which negatively expressed Her-2. Our current research indicated that the synthesized nonviral vector shows improved gene delivery efficiency and targeting specificity in Her-2 positive cells. 相似文献
908.
Zahra Afrasiabi Rosana Almudhafar Di Xiao Ekkehard Sinn Amitava Choudhury Aamir Ahmad Alok Vyas Fazlul Sarkar Subhash Padhye 《Transition Metal Chemistry》2013,38(6):665-673
A planar, polycyclic and aromatic hydrocarbon ligand, namely 9,10-phenanthrenequinone semicarbazone, and its transition metal complexes have been synthesized and structurally characterized. The in vitro antiproliferative activity of these compounds against five human cancer cell lines revealed that they were effective against androgen receptor-positive/negative prostate cancer cells as well as COX-positive pancreatic BxPC-3 cancer cell line. The driving force behind such antiproliferative activity seems to be the up-regulated COX expression in these cells, which was amenable for targeting through metal complexation. These structural motifs can, therefore, serve as a starting point for developing novel cytotoxic agents against the growing number of prostate and pancreatic cancers. 相似文献
909.
Jian‐Nan Xiang Li‐Hui Jiang Chao‐Yue Chen Zhi‐ying Fu Jun‐Fei Duan Xiao‐Xiao He 《Journal of carbohydrate chemistry》2013,32(7):595-614
New retinoyl sugar derivatives of 13‐cis‐retinoic acid were synthesized in three ways in this paper in order to enhance pharmacal effects, especially antiproliferative activities of 13‐cis‐retinoic acid. Their structures were confirmed by IR, 1H‐NMR, 13C‐NMR, and MS spectra and their antiproliferative activities were determined in vitro using human cancer lines. Results showed that some compounds possessed potential antitumor activities. 相似文献
910.
Zn(II) and Mn(II) organometallic complexes I and II were first used to catalyze the cyanosilylation reaction, and good catalytic results (24–99 %) were achieved. The catalytic activity of the complexes was determined by 1H NMR. 相似文献