Table of Content

10 November 2008, Volume 29 Issue 11

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高等学校化学学报2008年第29卷第11期目次

2008, 29(11):  0.  doi:

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研究论文

Preparation and Characterization of Hollow Ag Nanoparticles with Movable Au Cores Inside and Their Application to Surface-enhanced Raman Scattering

LI Li, YANG Wu^*, GUO Hao, CHEN Zhong-Yu, ZHANG Ai-Ju, JIN Li-Li, CHEN Miao

2008, 29(11):  2121-2126.  doi:

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Core-shell structure of Au@SiO₂ nanoparticles and silver coated Au@SiO₂ nanoparticles(Au@SiO₂@Ag NPs) were prepared by a seed-mediated growth technique under shaking. Hollow Ag nanoparticles with a shell thickness of 30 nm and with movable Au cores of 30 nm diameter inside(Au@air@Ag NPs) were further obtained by dissolving silica shell within Au@SiO₂@Ag NPs by HF. The morphologies of those obtained nanoparticles were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The application of the as-prepared Au@air@Ag substrates in surface-enhanced Raman scattering(SERS) was investigated with Rhodamine B as a probe molecule. It was found that even though very low concentration of Rhodamine B adsorbed on the hollow nanoparticles showed a strong SERS effect. The results indicate that the Au@air@Ag NPs were ideal materials applied in SERS.

Synthesis of Novel 3D Lanthanide Oxide Nitrate Compounds with the Zeolite SOD Topology

WANG Li-Feng¹, LI Hua^1,2, ZHU Guang-Shan¹, REN Hao¹, SUN Fu-Xing¹, QIU Shi-Lun^1*

2008, 29(11):  2127-2130.  doi:

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A series of lanthanide oxide nitrates(Ln=Y, Tm, Yb, Lu) constructed by nanoscale cages with a zeolite sodalite topology structure were prepared through the hydrothermal method. The compounds are isomorphous and crystallize in the trigonal R-3 space group. The framework expands the original structure of SOD nanocage from 0.9 nm to 1.4 nm. The lanthanide ions are eight-coordinate with six bridge oxygen atoms and two oxygen atoms coming from nitrate ions. If the nitrate ions were ignored, the compound can be described as a rare lanthanide oxide structure with 3-dimensional open framework.

Synthesis and Photodynamic Activity of a New Type of Pentalysine 2-Carbonylphthalocyanine Zinc

CHEN Jin-Can¹, CHEN Hong-Wei¹, LI Yong-Dong¹, WANG Jun-Dong², CHEN Nai-Sheng², HUANG Jin-Ling², HUANG Ming-Dong^1*

2008, 29(11):  2131-2137.  doi:

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Phthalocyanine zinc(ZnPc) and its derivatives is a class of promising photosensitizer due to its superior photodynamic activity. However, the poor water solubility and the difficulty to obtain pure ZnPc compounds limit the clinical development of this class of photosensitizer. We developed a large scale preparation and purification of a new asymmetric phthalocyanine zinc compound, 2-carboxyphthalocyanine zinc. Here we report the synthesis of pentalysine 2-carbonylphthalocyanine zinc and its photodynamic activity. The compound was characterized by analytical and spectroscopic methods. The phototoxicity of this compound was evaluated in vitro with human liver cancer cell line(Bel7402), human gastric carcinoma cell line(BGC823), human leukemia cell line(K562) and human embryo lung fibroblast cell line(HELF). This compound shows not only the phototoxicity to these cells, but also improves water solubility. We also demonstrate that the presence of cell breaks down the aggregation of pentalysine 2-carbonylphthalocyanine zinc in aqueous solution.

Preparation of Phosphocholine Chromatographic Stationary Phases and Their Application to Separation of Proteins

XU Li-Zhen, GONG Bo-Lin^*

2008, 29(11):  2138-2141.  doi:

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2-Methacryloyloxy ethyl phosphorylcholine(MPC) was prepared by the reaction of phosphorylcholine dichloride with 2-hydroxyethyl methacrylate(HEMA). The novel phosphocholine chromatographic stationary phase was synthesized by free radical graft polymerization of MPC from the surface of porous silica particles. The polymerization was initiated by thermal cleavage of tert-butylperoxy groups covalently attached to the particle surface. The stationary phase was evaluated in detail to determine its separability and to study the effect of pH on the retention of proteins. The dynamic protein loading capacity of the synthesized phosphocholine chromatographic stationary phase for Lys and BSA was 13.8 and 18.7 mg/g, respectively. The experimental results show that two acid proteins and two basic proteins were separated with 10 min linear gradient elution via the synthesized phosphocholine stationary phase.

Determination of Trace Bisphenol A in Water by High Performance Liquid Chromatography with Dispersive Liquid-liquid Microextraction

LI Yu^1,2*, LIU Jian-Lin¹, WANG Xiao-Li², JIAN Ying-Hong², DONG De-Ming², LI Na²

2008, 29(11):  2142-2148.  doi:

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Determination of bisphenol A(BPA) of trace level in water was performed by dispersive liquid-liquid microextraction(DLLME) and high performance liquid chromatography. The optimal conditions of 22.5 μL of extraction solvent(chlorobenzene), 0.5 mL of disperser solvent(acetone), 0 min of extraction time, 10% of ionic strength, 3.2 of pH value and 9 mL of water sample volume, were obtained by screening and optimization design. Under the optimum conditions, the linear range is 0.50—100 μg/L(R²=0.9941) and the limit of detection is 0.10 μg/L for determination of BPA. The recovery from 87.8% to 111.0%, RSD of 8.3%(n=5) and enrichment factor from 1905 to 2527 were obtained at a mass concentration of BPA of 1 μg/L. The relative recoveries of BPA from tap water, river water and recycled water at spiking different levels are (108±11.1)%, (107±13.2)%, and (81.2±6.2)%(n=3), respectively. Moreover, under the determined chromatographic conditions, the effects of acetylene estradiol, estradiol, estriol, estrone and nonylphenol on the determination of BPA in water by high performance liquid chromatography with dispersive liquid-liquid microextraction were not of existence.

Amperometric Immunosensor Based on Covalent Immobilization of Monoclonal Carcinoembryonic Antibody(CEA) on Fe₃O₄/Au Nanocomposites

LI Jian-Ping^1,2*, GAO Hui-Ling¹, XIONG Zhi-Gang¹

2008, 29(11):  2149-2154.  doi:

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Fe₃O₄/Au magnetic nanocomposites were synthesized, then the surface of the magnetic nanocomposites was amino-functionalized with thiourea to covalent immobilization of monoclona carcinoembryonic antibody(anti-CEA) using glutaraldehyde. The resulting magnetic bio-nanocomposites were attached onto the surface of solid paraffin carbon paste electrode with the help of a permanent magnet to construct a new amperometic immunosensor. The immunosensor was incubated with mixed solution of carcinoembryonic antigen(CEA) and horseradish peroxidase labeled carcinoembryonic antigen(HRP-CEA) for 30 min to perform the competitive immune reaction between CEA(or HRP-CEA) and anti-CEA immobilizated on the surface. The concentrations of CEA were determined indirectly by competitive immunoassay method via the changes of the H₂O₂ concentrations resulted from the catalytic degradation by HRP. The sensitivity for CEA determination was greatly improved due to the amplification effect of labeled HRP on the catalytic degradation of H₂O₂, which led to the change of the concentration of p-hydroquinone. There is a linear relation between response current and logarithm of concentrations of CEA in the concentration range of 2—160 ng/mL, with a detect limit of 0.57 ng/mL(on a 3σ basis). The simple manipulations of construction, low cost, high sensitivity, sharp specificity and easy regeneration of the sensing platform were main advantages of proposed immunosensor.

Detection of Testosterone, Dihydrotestosterone, Dehydroepiandrosterone in Emasculated Rat Prostate via GC/MRM

CHEN Jun¹, LIANG Qiong-Lin¹, LI Hui², LUO Guo-An^1*, WANG Yi-Ming¹

2008, 29(11):  2155-2158.  doi:

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Prostate cancer is a common malignancy in men. For prostate dependent on androgen for growth, orchiectomy is adopted in clinical therapy along with medicines aimed to restrain the synthesis and secretion of androgens in adrenal. The function of adrenal androgen is not clear till now, therefore, it needs more consideration on how to operate the therapy properly. We established a GC/MRM method for the detection of androgens in tissue sample, by which we monitored the concentration of androgens in emasculated rat. It is shown that the influence of adrenal androgen on the hormone metabolism in prostate existed via this experiment.

Fabrication and Electrocatalysis of Multilayer Film Electrodes Based on MWCNTs@CHIT-Fc Composites

ZHOU Hong, SUN Chang-Qing^*

2008, 29(11):  2159-2163.  doi:

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Using the electrostatic self-assembly technique, the multilayer films containing multiwalled carbon nanotubes and ferrocene branched chitosan(MWCNTs@CHIT-Fc) and PSS were alternately fabricated on GCE modified with PDDA. The obtained thin films were characterized by CV, UV-Vis and SEM. The electrocatalytic oxidation of AA on the multilayer film electrode was studied in detail by CV. When the number of bilayers of MWCNTs@CHIT-Fc on the GCE is 6, the oxidation peak potential of AA was lowered by at least 0.4 V compared with that obtained at bare GCE. The current response of AA at different bilayers of MWCNTs@CHIT-Fc on the modified electrode was studied by amperometric method. The analytical performance of the modified electrode such as sensitivity, detection limit and linear range for AA determination can be turned to the desired level by adjusting the number of deposited MWCNTs@CHIT-Fc bilayers.

Resonance Rayleigh Scattering Spectra of the Interactions of HgCl₂-Cefotaxime Anionic Chelate with Basic Triphenylmethane Dye and Their Analytical Applications

FU Sheng-Hui, LIU Zhong-Fang, LIU Shao-Pu^*, HU Xiao-Li

2008, 29(11):  2164-2170.  doi:

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In pH 5.3—6.8 Britton-Robinson(BR) buffer medium, Cefotaxime sodium(CFTM) can react with HgCl₂ to form 1∶1 anionic chelate, which can further react with basic triphenylmethane dye such as crystal violet, methyl violet, ethyl violet, brilliant green, iodine green, methyl green and malachite green to form ternary ion-association complexes. As a result, the resonance Rayleigh scattering(RRS) spectrum was enhanced greatly. The maximum RRS wavelengths of three ion-association complexes were located at 367, 367, 340, 367, 340, 340 and 340 nm, respectively. The increments of scattering intensity(ΔI) were directly proportional to the concentrations of CFTM in certain ranges. The linear ranges and the detection limits(3σ) of CFTM for seven systems were 0.0090—3.5 μg/mL and 2.7 ng/mL(crystal violet), 0.0092—3.5 μg/mL and 2.8 ng/mL(methyl violet), 0.013—3.5 μg/mL and 4.0 ng/mL(ethyl violet), 0.010—3.5 μg/mL and 3.1 ng/mL(brilliant green), 0.011—3.5 μg/mL and 3.4 ng/mL(iodine green), 0.012—4.0 μg/mL and 3.5 ng/mL(methyl green), and 0.016—3.5 μg/mL and 4.7 ng/mL(malachite green), separately. The sensitivity of crystal violet system was higher than those of other six systems. The optimum conditions and the influence factors were investigated, and the composition of ion-association complexes and the reaction mechanism were also discussed. The effects of foreign substances were tested and it is shown that the method has a good selectivity. Based on HgCl₂ and basic triphenylmethane dye, the sensitive, simple and rapid method for the determination of trace CTRX was developed.

Preface

Metabonomics Research of Diabetes Mellitus and Diabetic Nephropathy Based on UPLC-oaTOF-MS System

ZHANG Jie*, YAN Li-Juan, LIN Lin, CHEN Wen-Gui, SONG Xiu-Yu, YAN Xiao-Mei, HANG Wei*, HUANG Ben-Li

2008, 29(11):  2171-2173.  doi:

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Ultra performance liquid chromatography(UPLC) coupled with orthogonal acceleration time-of-flight(oaTOF) mass spectrometry is becoming an effective and high-throughput analytical technique in metabonomics research. In this paper, an UPLC-oaTOF-MS system was employed to investigate the serum profiles of 40 diabete mellitus(DM)/diabetic nephropathy(DN) patients and 25 healthy volunteers in an effort to find potential biomarkers. The UPLC system produced information-rich chromatograms with typical measured peak widths of 4 s, and generated peak capacities of 225 in 15 min. After the UPLC-oaTOF-MS analysis, principal component analysis(PCA) was used for group differentiation and marker selection. In the projection of positive mode, DM/DN patients and the controls were obviously divided into three groups. Furthermore, two potential markers were identified as phytosphingosine and sphinganine, respectively. Phytosphingosine and sphinganine with decreased concentrations in the patients, were closely related to the sphingolipid metabolism.

研究论文

Comparative Proteomics Analysis of Huh7 Cells Harboring Intact HCV

ZHAO Si-Hai^1,2, XUN Meng¹, CHU Yong-Lie^1*, ZHU Tong³, XUE Xin¹, XU Kun¹, SONG Juan¹, SHAO Ming-Ming¹

2008, 29(11):  2174-2177.  doi:

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To analyze the protein expression changes of a human liver cell lines Huh7 in the absence and presence of HCV, proteomic techniques were used to establish the protein expression profiles. The differentially expressed proteomes between Huh7 cells and Huh7 cells with HCV were profiled and the 14 differentially expressed proteins were identified via two dimensional electrophoresis and MALDI-TOF-MS. Many proteins, included regucalcin, centriolin and several keratins, were up regulated expression after HCV transfection. Among down-regulated expression proteins, heat shock proteins were very attractive. Subsequently, we randomly identified the proteomics results by the detection of Hsp70 expression levels between Huh7 cells and Huh7 cells with HCV by western blot methods. Our study provides the global information of proteomic alteration of Huh7 cells in the presence of intact HCV and the clues for further understanding of the mechanism of interaction between HCV and host cell.

Synthesis and Bioactivity of Dibenzylbutane Lignans and Their Analogues

XIA Ya-Mu^1*, BI Wen-Hui¹, CAO Xiao-Ping²

2008, 29(11):  2178-2182.  doi:

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Lignans are widely distributed in the plant kingdom. Among lignans, many dibenzylbutane lignans and their analogues exhibit a strong bioactivity. A novel synthetic route to dibenzylbutane lignans using simple aldehydes as the starting materials is described. The method involves Stobbe Condensation and condensation of aromatic aldehyde and alkylation to give the complete skeleton of lignans. Then, by the resolution of (-)-diacid, a simple separation of threo- and erythro-isomers and structural modification, the target materials were obtained. Five dibenzylbutane lignans and eight dibenzylbutyl ether lignans were synthesized. Bioactivity results indicate that some compounds showed better activities against the HIV and herpes virus, and bioactivity is greatly affected by the skeleton configuration.

Cytotoxic Constituents from Marine Actinomycete Streptomyces sp. 124092

XIE Xiu-Chao^1,2, MEI Wen-Li¹, ZENG Yan-Bo¹, LIN Hai-Peng¹, ZHUANG Ling¹, DAI Hao-Fu^1*, HONG Kui^1*

2008, 29(11):  2183-2186.  doi:

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To study the cytotoxic constituents from marine actinomycete Streptomyces sp.(124092) of rhizosphere soil of mangrove plant Heritiera littoralis, five compounds were isolated by column chromatography from the fermentation broth of marine actinomycete Streptomyces sp.(124092). Their structures were elucidated as p-tolyl 3-aminopropanoate(1), 6-amino-3-(4-hydroxybenzyl)-1,4-diazonane-2,5-dione(2), n-butyl mannoside(3), daidzein(4), and indole-β-carboxylic acid(5), by MS, NMR, ¹H-¹H COSY, HMQC, and HMBC spectra. Among them, compounds 1 and 2 are new compounds. Cytotoxic bioassay results show that compounds 1—4 possess inhibitory effects on human hepatoma SMMC-7721 cell line in vitro.

Design and Synthesis of β-Elemene Glycoside Derivatives Containing Heteratom S or Se

YANG Lan-Yi¹, ZHANG Shu-Jia^1,2, ZHENG Xue-Fang^2*, YIN Hong-Xing¹

2008, 29(11):  2187-2190.  doi:

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For the purpose of hunting for better water solubility and anti-tumor activity derivatives, structural modification of anticancer agent β-elemene was reported. Significant heteroatom S and Se were introduced into the skeleton of β-elemene and a pair of bioisosteres 3, 6 were obtained. Whereafter, conjugation with a series of glycosyls selectively gave the corresponding 1,2-trans-glycosides 11a—11c, 12a—12c via several approaches. Then target compounds 13a—13c, 14a—14c were obtained in high yields after deprotection. Heteroatom Se and hydrophilic saccharides were introduced into the skeleton of β-elemene for the first time, and a convenient method was set up for the synthesis of selenide of β-elemene. The glycosylation results demonstrate that glycosyl trichloroacetimidate was a suitable donor for the glycoside synthesis of β-elemene. The structures of products were confirmed via IR, ¹H NMR, ¹³C NMR, ⁷⁷Se NMR and HRMS spectra.

Total Synthesis of Ligudentatin A

ZHANG Chen-Xi, BI Fu-Qiang, LI Yu-Lin^*

2008, 29(11):  2191-2193.  doi:

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Ligudentatin A(1), a new phenolic norsesquiterpenes, was first synthesized starting from (+)-perillalalcohol 2 through six steps, successively, with an overall yield of 17.7%. The key steps were the Diels-Alder reaction and aromatization of enone to phenol. The advantages of this approach are reasonable yields and the ease with which the reaction can be carried out with readily available materials and reagents under mild conditions.

Investigation of Post-translational Modifications of Proteins in the Venom of Chinese Gloydius Shedaoensis Snake by Mass Spectrometry

LIU Shu-Qing^1*, SUN Ming-Zhong^2*, ZHAO Bao-Chang¹

2008, 29(11):  2194-2200.  doi:

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SDS-PAGE was employed to the separation of the venomic complex of Chinese Gloydius Shedaoensis snake localized at Lüshun. The glycosylated and phosphorylated protein components were visualized by the Pro-Q Emerald 488 glycoprotein staining and Pro-Q Diamond phosphoprotein fluorescent dyes. Protein identification of the selected protein bands were performed the HPLC-nESI-MS/MS proteomic approach. Eight glycoprotein bands in the gel were identified as the homology proteins of L-amino acid oxidase, metalloproteinase, glutaminyl cyclase, salmobin, plasminogen activator, halystase, phospholipase A₂(PLA₂), nerve growth factor and truncated/degraded L-amino acid oxidase products at the N-terminus, which posses homology peptides originated from other kinds of snake venoms. The five phosphoprotein bands visualized by Pro-Q Diamond dye were identified as stejaggregin-A, PLA₂, Crisp, metalloproteinase P-Ⅲ and acutolysin e precursor homology proteins. To validate this approach, a novel PLA₂ was purified from this venom to homogeneity by the ion-exchange and gel filtration chromatography. The results from Pro-Q Diamond staining and mass spectrometry identification indicate that the purified PLA₂ sharing certain homology peptides of PLA₂s from other snake venoms. Our experimental results provide new insights for further making a research on the relationship between the post-translation modifications of snake venom proteins and their biological functions and structures.

Plasmid DNA Cleavage by Valine-Schiff Base-Cu Complexes

WANG Chang-Rong¹, LÜ Jian², GAO Lu¹, WANG Yong-Mei², ZHANG Jin-Hong^1*

2008, 29(11):  2201-2204.  doi:

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Valine-Schiff base-Cu(PBP-L-Val-Cu), which is a nonenzyme DNA-cleavage complex, contains four different forms: L-CH₃, D-CH₃, L-Ph and D-Ph. To obtain the most efficient activity, we test the cleavage activity of complexes under different conditions using pUC18 from E.Coli as DNA sample. Plasmid pUC18 was cleaved by the four certain complexes seperately and the products cleaved in variance of time were examined through agarose gel electrophoresis. In this way, we compare the cleavage ability of PBP-L-Val-Cu complexes in cleaving supercoiled DNA into nicked or linear DNA product, and then we find that L-CH3 has the highest activation in cleaving supercoiled plasmid DNA. Futhermore, we purificate the linear DNA product by TIANgel Midi Purification Kit, and this linear DNA extraction could be connected again by T4 DNA ligase. Finally, we incided the linear DNA extraction with two different kinds of restriction enzyme. The results show that this complex can cleave DNA in a site-specific way. Moreover, PBP-L-Val-Cu can also cleave other plasmid DNA, such as pNQ216 from Bacillus subtilis.

Structural Analysis of Polysaccharide SJB from Mulberry Leaves and Its Inhibitory Activities of Protein Tyrosine Phosphatase-1B

XIA Wei¹, ZHANG Wen-Qing^1*, LUO Guo-An²

2008, 29(11):  2205-2208.  doi:

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A pectic polysaccharide SJB was obtained from the alkali extract of mulberry leaves by DEAE-cellulose and gel filtration chromatography. The structures of SJB were identified on the basis of chemical methods(sugar component analysis, methylation analysis, partial acid hydrolysis) and spectral method(IR, ESI-MS, NMR). The results show that SJB with a molecular mass of 5.4×10⁴ consisted of rhammose, arabinose, glucose, galactose and galacturonic acid units in the molar ratio of 1.00∶1.26∶0.66∶2.04∶0.95. The main chain of SJB includes 1,2-linked, 1,2,4-linked Rhap and 1,4-linked, 1,3,4-linked GalAp. The side chains are mainly attached to the O4 of Rhap residues and O3 of GalAp residues, including terminal, 1,5-linked, 1,3,5-linked Araf and terminal, 1,4-linked Glcp, and terminal, 1,4-, 1,3-, 1,6-linked Galp. SJB is a new acidic polysaccharide for the first time isolated from Muberry leaves. The study of the effect of lowering blood glucose of SJB shows the inhibitory rate of SJB to PTP1B is 31.7% at the concentration of 20 μg/mL.

Integrated Cultivation and Photohydrogen Production of Tetraselmis Subcordiformis in a Flat-plate Photobioreactor System

ZHENG Yang^1,2, CHEN Zhao-An¹, FU Yun-Bin^1,2, LU Hong-Bin¹, ZHANG Wei^1*

2008, 29(11):  2209-2212.  doi:

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This paper aimed to develop an integrated processes of microalgal cultivation and hydrogen photoproduction in a flat-plate photobioreactor system combined with alkaline fuel cell. The optimal high cell density of 8.5×10⁶ cell/mL was achieved on 9 d when the cultivation of Tetraselmis subcordiformis was supplemented with CO2 of 2%—5%(volume fraction) in the flat-plate photobioreactor. When the bioreactor system was switched to the hydrogen production condition, hydrogen evolution was induced by the addition of carbonylcyanide(m-chlorophenylhydrazone, CCCP) and anaerobic condition, with a maximum hydrogen production rate of 1.1 mL/(h·L) for 60 h. The kinetics analysis of algal chlorophyll fluorescence was carried out to identify the limiting factors in both algal growth and hydrogen production at 2%CO₂ supplementation. At hydrogen production phase, algal PSⅡactivity and relative electron transfer rate(rETR) decreased with the increase of time, which caused the decline and eventual stop in hydrogen production. To sustain the hydrogen production, PSⅡactivity and rETR must be maintained. The results demonstrate the feasibility of process integration of algal cultivation and hydrogen production in one single system, which will significantly improve the process economics.

VHSEH Descriptors for the Development of QSAMs of Peptides

YANG Shan-Bin^1,2,4, XIA Zhi-Ning^1,2*, SHU Mao^1,2, MEI Hu^1,2 , LÜ Feng-Lin³, ZHANG Mei⁵, WU Yu-Qian², LI Zhi-Liang^1,2

2008, 29(11):  2213-2217.  doi:

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A new set of descriptors, VHSEH(principal component score vector of hydrophobic, steric, electronic properties, and hydrogen bonds contributions), was derived from principal components analyses of 171 physicochemical variables of 20 natural amino acids separately according to different properties described, namely, hydrophobic, steric, and electronic properties, hydrogen bonds contributions. VHSEH scales were employed to express the structures of oxytocin analogues, antimicrobial peptides and angiotensin-converting enzyme inhibitors. The correlation coefficients R₂ and cross validation Q₂ for the multiple-variable models by PLS and PLS by D-Optimal Designs of oxytocin analogues were 0.958 and 0.903, 0.957 and 0.845, respectively. R₂ and Q₂ for the models by PLS and OSC-PLS of bactericidal peptides were 0.84 and 0.546, 0.995 and 0.926, respectively. The value of R₂, Q₂ and RMS in the PLS model of angiotensin-converting enzyme inhibitors were 0.877, 0.838 and 0.361, respectively. Satisfactory results show that, as new amino acid scales, data of VHSEH may be a useful structural expression methodology for the study on quantitative sequence-activity modeling(QSAM) of peptides, due to its many advantages such as plentiful structural information, definite physical and chemical meaning and easy interpretation.

Preparation and Application of the Polymer Powder with High Density of Free Aldehyde Linkers

SUN Zi-Cai, WEI Zheng^*, WEI Ke-Mei

2008, 29(11):  2218-2222.  doi:

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When a diluted poly(vinyl alcohol)(PVA) aqueous solution was slowly dropped into excess 25% glutaraldehyde solution, the obtained product was not the normally formed hydrogels(by gelation method) but plastic white powder with numerous free —CHO groups on the surface. The density of the useful —CHO groups was both calculated in theory(>5.5 mmol/g) and chemically determined(>1.6 mmol/g). The length of the —CHO linkers was prolonged by reacting with the amino compounds and the functional groups correspondingly changed to be —NH₂, —SH, or —NH—NH₂. All the synthesized macromolecular compounds generally have hydrophilic three-dimensional surface, in sufficient quantities and flexible functional groups and low fluorescent background, such synthesized macromolecular compounds are good for fabrication of the bio-microarrays, especially carbohydrate arrays. For example, the powders with groups of both the —CHO and —NH—NH2 were used to immobilize the heparin. Anticoagulant experiments show that the immobilized molecules still played a good biological function.

Influence of MnO₂ on the Photocatalytic Activity of TiO₂ Under Different UV Sources

GONG Ya-Min¹, MA Zi-Chuan^1,2*, LI Shun-Jun¹, ZHANG Jie¹, LIU Jing-Ze^2*

2008, 29(11):  2223-2226.  doi:

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The influences of MnO₂ particles on the photocatalytic activity of Degussa P-25 TiO₂ were investigated with kinetical method under three kinds of UV sources, which are UV365/28 W, UV302/16 W and UV254/25 W. α-MnO₂, β-MnO₂ and δ-MnO₂ were introduced in the experiment. The results show that TiO₂ photocatalyst deactivates due to the presence of MnO₂ particles under UV365/28 W and UV302/16 W, while the photocatalytic activity of TiO₂ basically keeps stable photocatalysis activity under UV254/25 W. In conclusion, the stability of TiO₂ photocatalyst is significantly related to the wavelength of UV sources.

Reaction Mechanism of Preparation of Ag Nanoparticles by Adsorption Phase Reaction Technique

WANG Ting, JIANG Xin^*, MAO Cong-Wen

2008, 29(11):  2227-2231.  doi:

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Ag nanoparticles were prepared on SiO₂ surface at different temperatures via adsorption phase reaction technique. The influence of temperature on adsorption of NaOH, reduction reaction of Ag and morphology of Ag nanoparticles was studied. Measurement results of adsorbed NaOH indicate that adsorption of NaOH needed more time to reach equilibrium with temperature increasing. The reaction of NaOH with Si—O—Si became more rapid due to increase of temperature, which resulted in little change of equilibrium percentage of NaOH with decrease of adsorption layer. The reduction reaction of Ag was characterized by UV-Vis adsorption spectra. The results suggest that when temperature reached 40 ℃, induction time, concentration and size distribution of Ag nanopartcles all changed greatly. When temperature increased to 40 ℃, there was great glomeration in morphology of sample analyzed by TEM and a sharp increase appeared in grain size gained by XRD. Adsorption layer was destroyed with temperature increasing, which resulted in the generation region of Ag nanoparticles transferred from adsorption layer to SiO₂ surface. Moreover this change of reaction region resulted in the great change of reduction reaction mechanism of Ag and morphology of particles.

Preparation and Characterization of TiO₂ Photocatalyst Co-doped by Nitrogen and Nickel with Concentration Gradient Distribution

BAI Yuan, SUN Hong-Qi, LIU Hui-Jing, JIN Wan-Qin^*

2008, 29(11):  2232-2238.  doi:

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Nitrogen and nickel co-doped TiO₂ photocatalyst was synthesized by the combination of precipita-tion with layer-by-layer impregnation, in which titanium tetrachloride was used as Ti-precursor and ammonia, nickel chloride as doping-ion donors. The samples were characterized by means of X-ray diffraction(XRD), nitrogen adsorption-desorption, X-ray photoelectron spectroscopy(XPS) and UV-Vis spectroscopy(UV-Vis). The as-prepared photocatalyst was dominantly in anatase phase and a mesoporous structure. The doped nitrogen and nickel impurities were found to be NO_x and Ni₂O₃, NiO species, which were confirmed by XPS. The photocatalytic activity of co-doped TiO₂ was higher than that of both pure and single doped one. Visible light response was due to NO_x and the doped nickel maintains the charge balance at the same time. Simul-taneously, the special concentration gradient distribution of Ni in this work reduced the possibility of recom-bination of photogenerated holes and electrons, which seemed to contribute to the enhancement of the photo-catalytic activity of nitrogen and nickel co-doped TiO₂.

Research on the Properties of Gelling Process of Waxy Crude Oil

LIN Ming-Zhen, LI Chuan-Xian^*, YANG Fei, YU Zhen-Hua, LIU Ya-Hui

2008, 29(11):  2239-2244.  doi:

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The gelling processes of waxy crude oil under three different historical conditions were studied in detail. The RS75 rheometer was used in a small amplitude oscillatory shear mode in the study. Meanwhile, the morphology of wax crystals in the waxy crude oil at different cooling rates was investigated through a polarized light microscope. The results show that the gel point of the waxy crude oil becomes lower and the strength of the gel structure reduces with the increase of the cooling rate under quiescent conditions. As the crude oil is kept static under isothermal conditions, with the increase of cooling rate, the recovery rate of the structure increases and the time needed for recovering to balance extends, but the strength of the final balance structure is weaker .At the same cooling rate, the strength of the gel structure for waxy crude oil at a low temperature reduces with the increase of historical shear rate. However,when the historical shear rate exceeds a critical value, the strength of the gel structure keeps nearly unchanged. At the same historical shear rate, the higher the cooling rate is, the smaller the initial storage modulus at low temperature(31 ℃) is and the stronger the strength of final balance structure is.

Surface Enhanced Raman Spectroscopic Studies of the Adsorption of Thiocyanate at Pt Electrode in Ionic Liquids

NIU Tian-Chao, YUAN Ya-Xian, WANG Mei, YAO Jian-Lin, SUN Ru, GU Ren-Ao^*

2008, 29(11):  2245-2248.  doi:

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The adsorption behavior of thiocyanate(SCN^-) on the Pt electrode in the room-temperature ionic liquids of 1-n-butyl-3-methylimidazolim tetrafluoroborate([BMIM]BF₄) was investigated by electrochemical in situ surface enhanced Raman spectroscopy(SERS). The results revealed that SCN^- adsorbed onto Pt surface in a wide potential region, and the adsorption behavior of SCN^- changed with the variation of the potential. Different Stark effects were observed in different potential regions, i.e. the S—Pt bonding exhibited the Stark shift of 34 cm^-1/V over the range from -0.9 V to 0.4V, and Stark shift of 40 cm^-1/V over the range from -1.6 V to -1.2 V for the N—Pt interaction. There is a transition region for the S- or N-adsorption between -0.9 V and -1.1 V. The change in the Stark effect in the different potential regions suggests that the potential of zero charge(p_zc) of the [BMIM]BF₄-Pt system is around -1.1 V(vs. Pt).

Three-liquid-phase Equilibria of Ternary System Water-Cyclohexane-Diethylene Glycol Monobutyl Ether

HOU Hai-Yun^1,2*, LIU Song-Tao¹, GENG Xin-Peng¹

2008, 29(11):  2249-2253.  doi:

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The equilibria of the three-liquid-phase for ternary system water-cyclohexane-diethylene glycol monobutyl ether were determined by the improved volume method, at the same time, the coexisting curves of the temperatures versus the volume fractions and the mass densities of the coexisting three liquids phases are reported. It is found that the coexisting curves of the temperatures versus the volume fractions of water, cyclohexane and diethylene glycol monobutyl ether are respectively inverse “S” type curve, positive “S” type curve and “knot-shape” curve. Simultaneously, when the volume fractions of coexisting three-liquid-phases are converted into mass densities, it is also found that the coexisting curve of temperatures versus mass densities of phases is also standard inverse “S” type curve. Furthermore, the three “S” type curves are all asymmetric, and the mass density may be used to describe the phase-equilibrium, moreover, the mass density may really be a good order parameter to describe the critical scaling behaviour.

Electrooxidation of p-Methylphenol at Different Catalyst Electrodes

TIAN Mei^1*, YANG Li-Juan¹, CUI Rui-Hai¹, ZHANG Heng-Bin², HE Fang¹, LIU Yan-Chun¹

2008, 29(11):  2254-2257.  doi:

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The electrocatalytic activity of Ti/PbO₂, graphite and platinum electrodes for the electrooxidation of p-methylphenol was studied by linear sweeping voltammetry and galvanostatic electrolysis in an electrolytic cell without diaphragm. The conversion, degradation rate, reaction mechanism and rate determining steps of p-methylphenol at the three kinds of electrodes were explored by determinations of p-methylphenol and intermediates in the electrolyte before and after electrolysis. The experimental results indicate that Ti/PbO₂ electrode with a high activity can effectively oxidize and remove p-methylphenol; graphite electrode can also oxidize p-methylphenol, but its removal ability was poor; platinum electrode can only oxidize p-methylphenol to hydroquinone in the electrolytic time of 3 h; p-methylphenol can not be oxidized completely. The mechanism of the electrooxidation degradation of p-methylphenol may be p-methylphenol→p-hydroxy-benmethanol→p-hydroxybenzaldehyde→p-hydroxybenzoic acid→hydroquinone→benzoquinone→maleic acid→oxalic acid, and the final product is CO₂. The electrooxidation reactions of hydroquinone and maleic acid are the rate determining steps for Ti/PbO₂ electrode, while the electrooxidation reaction of hydroquinone is a rate determining step for graphite electrode.

Effect of Operating Condition on Cathodic EIS Parameters in a DMFC

JIN Bao-Duo, GUO Jian-Wei, XIE Xiao-Feng^*, WANG Shu-Bo, WANG Jin-Hai

2008, 29(11):  2258-2261.  doi:

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Optimization of direct methanol fuel cell(DMFC) temperature and flow rate can effectively prevent cathode “flooding”, reduce the adverse effects of methanol crossover on cathode reaction, therefore, it is critical to improve the performance of DMFC. In this paper, we reduced the cathode catalyst loading to strengthen electrochemical polarization of DMFC cathode oxygen reduction reaction, and measured polarization curves and electrochemical impedance under different operating conditions. Moreover, an improved equivalent circuit model LR(CR)(QR(LR)) is built to fit the measured spectrum to analyze the effect of operating parameters such as temperature, air flow rate, methanol flow rate on the cathode electrochemical reaction and mass transfer polarization process of DMFC under the full cell conditions. The results show that: increasing temperature will lead to more methanol to permeate to the cathode, and increase the charge transfer resistance of cathodic oxygen reduction reaction; and only using the high air flow can effectively prevent cathode flooding, and improve oxygen mass transfer to the catalyst; appropriately increasing the flow of methanol can promote the electrochemical reaction of DMFC, but the excessive flow of methanol may lower electrode surface temperature, increase penetration of methanol, therefore adversely affect oxygen reduction reaction.

Theoretical Simulation for the Emission Spectrum of Microwave-driven Sulfur Lamp

GAI Zhi-Qiang¹, YU Xin¹, YAN Bing^2*, CHEN Fei¹, LI Rui², ZHAO Shu-Tao², PAN Shou-Fu², CHEN De-Ying¹, WANG Fu-Li¹, YU Jun-Hua^1*

2008, 29(11):  2262-2266.  doi:

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The emission spectrum of microwave-driven sulfur lamp was obtained by experimental measurement. The emission moment of S₂ B³Σ_u^-X³Σ_g^- and B″³Π_u-X³Σ_g^- electronic states and the Franck-Condon factors between their vibrational level were calculated by quantum ab initio method of multi-configuration quasi-degenerate perturbation theory and cc-pVQZ basic set, then, their emission spectra were derived. Absorption spectra of S_n(n=2—8) molecules were also calculated via time-dependent density functional theory. The emission spectrum and experimental one of S₂ molecules were took step to compare and analyze. The results can be used to well explain the emission spectrum characteristic of the microwave-driven sulfur lamp. The theoretical simulation results can well guide the further experiments to fit better with sun′s spectrum.

Density Functional Method Studies on Configuration and Electronic Structure of R—ReO₃

HE Xu-Min^*, YANG Pei-Xie, CHEN Zhe-Ning, FU Gang, XU Xin

2008, 29(11):  2267-2272.  doi:

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We performed a systematic densities functional(X3LYP) study on the configuration and electronic structures of a series of high valence organorhenium oxides(R—ReO₃·L_n). Our calculations show that X3LYP function can give a good description of rhenium oxide geometries. In most cases, the deviations of bond lengths from the experimental results are less than 0.001 nm, while the errors of bond angels are around 1°. We found that the Lewis acidity and the strength of the Re—O bond could be subtly tuned by various R groups as well as amine ligands such that rhenium oxo can play a versatile role in catalytic oxidation. These results are rationalized in terms of NBO analysis and frontier orbital theory.

Theoretical Studies on Conformational Distribution of Poly(vinylidene choloride

ZHANG Zhi-Jie, LÜ Zhong-Yuan^*, LI Ze-Sheng, SUN Chia-Chung

2008, 29(11):  2273-2276.  doi:

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Geometries and energies of various low-energy conformers of the stereoisomers of 2,2,4, 4-tetrachloropentane and 2,2,4,4,6,6-hexachloroheptane were determined at the MP2 level with a 6-311++G** basis set. For 2,2,4, 4-tetrachloropentane, the energy of the conformer with gauche-gauche arrangement is lower; For 2,2,4,4,6,6-hexachloroheptane, the conformer with trans-gauche-trans-gauche arrangement is stable. In contrast, the conformer with trans-trans arrangement is unstable and the energy is higher. Based on the quantum calculations, the first- and second-order characteristic interaction can be obtained by comparing the energies among different conformers of the stereoisomers which are used to determine the statistical weight parameters in a rotational isomeric state model. According to the geometries of the conformers and the statistical weight parameters, we can construct six-state statistical weight matrices. Furthermore, the populations of CH₂ and CCl₂ centered dihedral pairs in poly(vinylidene chloride) are determined from the quantum chemistry based rotational isomeric state model.

Theoretical Studies on Electronic Structures and Spectroscopic Properties of 1,3-Diazaazulene Derivatives

LI Man-Yu^1,2, ZHU Yun-Ji², AI Xi-Cheng^2*, SUN Meng-Tao³, ZHANG Jian-Ping²

2008, 29(11):  2277-2280.  doi:

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The geometries of four different kinds of 1,3-diazaazulene derivatives were fully optimized with Density Function Theory(DFT) at B3LYP/6-31G(d) level, on basis of which the energies of frontier molecular orbitals and the energy gap were investigated and the electronic transition properties were calculated with time-dependent DFT(TD-DFT) at the same level. The excited-state properties and the intra-molecular charge transfer(ICT) character were investigated with the two-dimensional(2D) and three-dimensional(3D) real space analysis methods. The electron-hole coherence is investigated with 2D contour plots of transition density matrix. The orientation and strengths of absorptive transition dipole moment are obtained by 3D transition density(TD). The ICT orientations are obtained with 3D charge difference density(CDD).

Structures, Thermochemistry and Electron Affinities of the Selenium Hydrides SeH_n/SeH_n^-(n=1—5)

XU Wen-Guo^*, BAI Wang-Jun, LU Shi-Xiang

2008, 29(11):  2281-2288.  doi:

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Seven different density functional theory(DFT) methods were employed to predict the molecular structures, electron affinities, and first dissociation energies of the SeH_n/SeH_n^-(n=1—5) molecules. The three type of electron affinities reported in this work are the adiabatic electron affinity(E_Aad), the vertical electron affinity(E_Avert), and the vertical detachment energy(VDE). The basis set used is of double-ζ plus polarization quality with additional s- and p-type diffuse functions, labeled as DZP++. The ground states of SeH/SeH^-, SeH₂/SeH₂^-, SeH₃/SeH₃^-, SeH₄/SeH₄^- and SeH₅/SeH₅^- are C_∝v/C_∝v, C_2v(²A₁)/C_s(²A′), C_s(²A₁)/C_2v(¹A₁), C_2v(¹A₁)/C_4v(²A₁), C_4v(²A₁)/C_4v(¹A₁), respectively. Compared with the experimental values, the B3P86 and B3PW91 methods give good results for the molecular structures, the BLYP method in all of these schemes is the best in respect of predicting electron affinities, the BP86 method determines the vibrational frequencies in best agreement with experimental data, meanwhile, the BHLYP methods gives good results for the first dissociation energies.

Construction of PEGylated Polyplexes via Self-organizing Blend

WANG You-Xiang*, CHEN Ping, HU Qiao-Ling, SHEN Jia-Cong

2008, 29(11):  2289-2293.  doi:

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An easy and favorable approach has been developed to prepare hydrophobic-driven PEGylated polyplexes via self-organizing blend of PEG-containing amphiphilic polymer. Poly(ethylene glycol) cholesterol ether and PEO-PPO-PEO was chosen as an amphiphilic polymer respectively. The results indicate that different amphiphilic polymers have great influence on the stability and transfection efficiency of polyplexes under physiological condition. Hydrophobic interaction is the key point to fabricate stable PEGylated polyplexes. By selecting the proper amphiphilic polymer, stable PEGylated polyplexes were fabricated successfully to improve stability and transfection efficiency at a physiological salt concentration. This facile approach to prepare the PEGylated polyplexes via self-organizing blend may have great potential in non-viral gene vector research and application.

Preparation of Poly(L-lactide)/Surface-Grafting Silica Nanocomposites and Their Surface Induction of Bone-like Apatite in Simulated Body Fluid

YANG Yan¹, YAN Shi-Feng¹, LI Xiao-Xiu¹, YIN Jing-Bo^1*, CHEN Xue-Si^2*

2008, 29(11):  2294-2298.  doi:

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In order to improve the dispersibility of nano-silica(SiO₂) in the matrix of poly(L-lactide)(PLLA), the silica nanoparticles were surface-grafted with L-lactic acid oligomer. The surface-grafting reaction is confirmed via IR, ²⁹Si MAS NMR and TGA analyses. The nanocomposites of surface-grafting silica(g-SiO₂) with PLLA prepared through solvent-cast technique were immersed in simulated body fluid(SBF) to examine their bioactivity. Its apatite-forming ability was characterized by means of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectra, scanning electron microscopy(SEM) and energy-dispersive spectrometer(EDS). The results show that L-lactic acid oligomer can be successfully grafted onto silica surface. The highest grafting amounts of L-lactic acid are 9.22% when the reaction time is 36 h. With the increase of filler content and soaking time, the amorphous surface coating is transformed into carbonated hydroxyapatite(CHA), the molar ratio of Ca to P is about 1.72, close to that of apatite. This kind of nanocomposites could be one of the best potential bioactive materials for bones substitute or as a tissue engineering scaffold.

Rate-accelerating of Boric Oxide for Atom Transfer Radical Polymerization of Styrene

LIN Rui, ZHUANG Jia-Ming, XU Rui, ZHAO Jun, LIN Hua-Duan, ZOU You-Si^*

2008, 29(11):  2299-2302.  doi:

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The polymerization of styrene was mediated by copper(Ⅰ) bromide/pentramethyltriamine(PMDETA) using ethyl 2-bromopropionate(EBP) as an initiator and boric oxide(BO) as a rate-accelerating additive.BO was found to be effective to accelerate ATRP of styrene, and the conversions were improved to 78.5% during 6 h at 85 ℃. An optimal molar ratio of BO/EBP for the polymerization of styrene was 4∶1. First-order kinetics, increase of M_n with respect to conversion, and the relatively narrow polydispersity demonstrate that the polymerization of styrene in the presence of BO proceeds in a living fashion. The apparent rate constant of polymerization was improved by a factor of 1.82, 1.54 and 1.5 at 65, 75 and 85 ℃ respectively. NMR spectra study indicates that no influence occurred on the structure of polystyrene when BO was added as promoter. BO is likely to solve the slow polymerization rate of ATRP and promote its industrial application.

Preparation and Properties of Composite with Simultaneous Adsorption of Oil and Chromium(Ⅵ)

LIU Xiu-Qi¹, ZHANG Guo^1*, XING He-Qin²

2008, 29(11):  2303-2307.  doi:

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A new kind of material for oil and Cr(Ⅵ) absorption was prepared by melt blend, with ethylene propylene diene monomer(EPDM) as the matrix and calcinatory Fe₂O₃ and anion exchange resin 201Х7 as the fillers. The composites can suspend in water-oil contact(WOC). The absorbencies of composites for water and oil changed greatly with various ratios of calcinatory Fe₂O₃ and anion exchange resin 201Х7. The results show that the absorbency of oil into the composite increased continuously while that of Cr(Ⅵ) was step-up with anion exchange resin loadings from 1% to 7%. The optimized ratio of calcinatory Fe₂O₃ and anion exchange resin 201Х7 was got when the absorbencies of composites for oil and Cr(Ⅵ) reached maximum simultaneously. The total adsorptive capacities of both oil and Cr(Ⅵ) were much higher than those of oil or Cr in one adsorption medium.

Preparation of Influenzal Vaccine Chitosan Microparticles by Ionic Gelation Method

SHI Jing^1,3, BAO Yong-Li^1*, WU Yin², YU Chun-Lei², LI Yu-Xin^2*

2008, 29(11):  2308-2311.  doi:

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Influenzal vaccine chitosan microparticles were prepared with tripolyphosphate(TPP) by ionic gelation method.The working mass fraction of chitosan was 1%. Morphologies of chitosan microparticles were affected by concentration of TPP, lower concentration of TPP(200 μg/mL) made the microparticle solution give sediment overnight, Whereas, higher concentration of TPP(800 μg/mL) made microparticles gather together . The release of vaccine from chitosan microparticles decreased when cross-linking ratio increased. The pH of chitosan solution had no effect on morphologies and release behavior. The results indicate that pH=5.6, cross-linking ratio 1∶3, mass concentration of TPP 400 μg/mL are the optimum conditions to prepare influenzal vaccine chitosan microparticles via morphologies and release behavior.

Separation and Purification of Lignosulfonate

YAN Ming-Fang, QIU Xue-Qing*, YANG Dong-Jie, HU Wen-Li

2008, 29(11):  2312-2316.  doi:

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Commercial sodium lignosulfonate(raw SL) was purified with ionic-resin method, ultrafiltration, long chain aliphatic amine extraction and solvent extraction. The structure, composition and molecular weights distribution of raw SL and purified SL were characterized by the Infra-red spectrum, elementary analysis and gel chromatography. The experimental results indicate that solvent extraction doesn't purify raw SL efficiently. Ionic-resin method, ultrafiltration and long chain aliphatic amine extraction removed impurities with molecular weight less than 1000; the content of lignosulfonate in purified SL was raised from 59% to 90%; the number average molecular weight and weight average molecular weight of purified SL were increased. In addition, the molecular weights distribution of purified SL became more uniform. Long chain aliphatic amine extraction could get rid of reducing sugar efficiently, the content of reducing sugar in the purified SL was reduced by 50%. The yield of purified SL with ultrafiltration is the highest, which can reach 31%. In comparison with the raw SL, the weight average molecular weight of the purified SL increase over once. Considering the purified SL yields, the purification efficiency and the purification technology, ultrafiltration is the best favorable purification method.

HUVEC Adhesion on Polylactides with Pendant Carboxyl Arms and Its Cell Activity

WANG Jun¹, WANG Wei¹, LIU Yuan¹, ZHU Xiao-Cui¹, YUAN Zhi^1*, TANG Shi-Ming², LIU Min², TANG Hua²

2008, 29(11):  2317-2320.  doi:

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In order to investigate the cell activity on the endothelialization surfaces, human umbilical vein endothelial cells(HUVEC) were seeded on poly(lactic acid)(PLA), poly(lactide-co-β-malic acid)(PLMA), its derivatives with hydroxyl arms(PLMAHE) and extended carboxyl arms(PLMACA) polymer films on the basis of our preliminary work. The amounts of endothelial nitric oxide synthase(eNOS) and nitric oxide(NO) released by endothelial cells were examined to study the anticoagulant property of endothelial cells adhered on polymer films. The platelet adhesion experiment was carried out to observe the amount and morphology of the platelets adhered on the endothelialization surfaces. The results show that the carboxyl functionalized surfaces have a better cell activity than PLA and PLMAHE, and copolymers with pendant carboxyl arms(PLMACA) could obviously preserve the HUVEC activity on the copolymer films compared with other materials. The amount of eNOS and NO released by HUVEC is (41.8±8.1) μmol/10⁴ cells and (0.76±0.16) U/10⁴ cells, respectively. The scanning electron microscopy(SEM) images demonstrate that endothelial cells adhered on the material surfaces could reduce the platelet adhesion and aggregation effectively. PLMACA also show a good blood compatibility on the exposed surface areas formed by the fallen of endothelial cells adhered on the material surfaces. In conclusion, the copolymer PLMACA is a hopeful material for vessel substitution with good HUVEC compatibility.

Synthesis and Photoluminescent Properties of Propeller-shaped Polyphenylenes Containing Hexaphenylbenzene Units

CHENG Ge^*, ZHAO Ling, WANG Yue-Chuan

2008, 29(11):  2321-2325.  doi:

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A novel propeller-shaped polyphenylene(9), based on hexaphenylbenzene-graphite subunits and a core molecule, 1,3,5-tris(4-styrylphenyl)benzene(8), was synthesized by Heck coupling reaction of 4-(4-vinylphenylene) hexaphenylbenzene(7) with 1,3,5-tris(4-iodophenylbenzene)(4). The structure of molecule 9 was characterized by FTIR, ¹H NMR, ¹³C NMR, GPC, MALDI-TOF mass spectrum, and elemental analysis. The absorption and photoluminescence spectra of propeller-shaped molecule 9 were investigated. Compared with structurally related chromophoric units including 4-vinylbiphenyl, 1-[4-(4-vinylphenyl)phenyl]-2,3,4,5,6-pentaphenylbenzene 7 and 1,3,5-tris(4-styrylphenyl)benzene 8, the absorption peak of molecule 9 was red-shifted to 355 nm. This molecule exhibited two maximum emitting peaks at 397 nm and 445 nm in the range of blue luminescence with photoluminescence efficiency being 19%.

Effect of Alkali Agents on Molecular Structure of PAC and Drilling-mud Fluid Loss

WANG Fei-Jun¹, SHAO Zi-Qiang^1*, WANG Wen-Jun¹, LÜ Shao-Yi¹, FENG Zeng-Guo¹, LIAO Bing²

2008, 29(11):  2326-2330.  doi:

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During the polyanionic cellulose(PAC) manufacturing in slurry process, the influence of alkali agent on the structure and characterization of PAC was studied by producing PAC with NaOH, KOH and mixture thereof. The cellulose fibre swelling ratio in different alkali systems decreases in the order as follows: NaOH/KOH(molar ratio 9/1), NaOH, NaOH/KOH(molar ratio 1/1), NaOH/KOH(molar ratio 1/9), KOH. Crystalline grade of cellulose is in the reverse order. These results were obtained by means of X-ray diffraction and microscope. The degree of substitution of PAC and substituent distribution within anhydroglucose unit(AGU) were determined by means of 1H NMR spectrum. The results show that the degree of substitution of PAC is higher and the distribution of the substituents in the anhydroglucose unit of PAC is more even in the presence of a little KOH. These made PAC have an excellent viscosity stability in salt and lactic acid and fluid loss resistance. When KOH was a major alkali agent, solubility of PAC in salt and lactic acid became worse and fluid loss increased.