Table of Content

24 May 2005, Volume 21 Issue 3

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Articles

Syntheses, Confirmation and Properties of Porphyrin Oligomers with Alkoxyl Linkages

LI Xiang-qing, SHI Ying-yan, YU Lian-xiang, WANG Xing-qiao, LIU Guo-fa

2005, 21(3):  253-257. 

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A new and general synthesis of a porphyrinK(Ⅰ) with two alkoxyl linkages is described. The synthesis involves the reaction of dibromopropane with phenolic porphyrin to form ω-bromopropylporphyrin ether. This ether then reacts with another phenolic porphyrin to give the target compounds. The properties of the target compounds were confirmed by means of elemental analysis, UV-Vis, IR, and ¹H NMR spectroscopies. Their spectral properties and thermal stability were also studied.

Thermal Behaviour of Some New Polyoxometalate Complexes of Ciprofloxacin with Keggin-type Heteropoly Acids

WANG Dun-jia, FANG Zheng-dong, HAN De-yan

2005, 21(3):  258-263. 

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Four polyoxometalate complexes, (CPFX·HCl)₃H₄SiW₁₂O₄₀, (CPFX·HCl)₃H₃PW₁₂O₄₀, (CPFX·HCl)₃H₃PMo₁₂O₄₀ and (CPFX·HCl)₄H₄SiMo₁₂O₄₀, were prepared from ciprofloxacin hydrochloride(CPFX·HCl) reacting with H_nXM₁₂O₄₀·nH₂O(X=P,Si; M=W,Mo) in an aqueous solution, and characterized by elemental analysis, IR spectrometry and TG-DTA. The IR spectrum confirms the presence of Keggin-type anions of heteropoly acids and the characteristic functional groups of ciprofloxacin. The TG/DTA curves show that their thermal decomposition is a multi-step process including simultaneous collapse of the Keggin-type structure. At first, these compounds had a mass loss of water molecules, then several other mass losses occurred due to the decomposition of ciprofloxacin hydrochloride and its fragments with the degradation of Keggin anions. The end product of decomposition is the mixture of WO₃(or MoO₃) and SiO₂(or P₂O₅), identified by X-ray diffraction and IR spectroscopy. The possible thermal decomposition mechanisms of these complexes are proposed. This study exemplified that the thermal stability of the complexes containing tungsten is much better than that of the complexes containing molybdenum.

12-Tungstophosphates Immobilized on Chemically Modified Mesoporous Silica SBA-15

ZHU Jing, YOU Wan-sheng, ZHU Zai-ming, SUN Zhen-gang, ZHANG Lan-cui, GU Yuan-peng

2005, 21(3):  264-267. 

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A functionalized material, PW/SBA-15m, was prepared successfully in diluted H₂SO₄ aqueous solutions by immobilizing 12-tungstophosphates on chemically modified mesoporous silica SBA-15 and characterized by elemental analysis, FTIR, ³¹P MAS NMR, XRD and TEM. The results indicate that the framework of SBA-15 and the Keggin structure of PW₁₂O₄₀^3- were retained, and that 23%-33%(mass fraction) of PW₁₂O₄₀^3- was immobilized; the PW₁₂O₄₀^3- anions were finely dispersed on the pore wall of SBA-15. Having been leached in ethanol at 60 ℃ for 7 h, the loss of PW₁₂O₄₀^3- anions was not found.

Separation and Determination of Methylnaltrexone in Human Plasma Samples After Oral Administration by HPLC Coupled with Electrochemical Detection

WANG An-bao, Joseph F. Foss, YUAN Chun-su, Joachim Osinski

2005, 21(3):  268-273. 

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A high performance liquid chromatography(HPLC) method coupled with electrochemical detection and solid phase extraction is described for the separation and determination of methylnaltrexone(MNTX), a quaternary opioid antagonist, in human clinical plasma samples after oral administration. Linearity of the standard curve for MNTX was found in the range of 4.0_150 ng/mL and was statistically conformed. The correlation coefficient(r²) and calibration equation obtained from linear regression analysis are 0.9999 and Y=54.27X-0.22, where Y and X represent the peak area and concentration of MNTX, respectively. The detection limit of MNTX under the present experimental conditions is 2.0 ng/mL by estimating at a ratio of 3 of signal to noise. The mean recovery of MNTX in human plasma is higher than 97%. The analytical method was applied to the pharmacokinetic determination of MNTX after single dose oral administration. These data demonstrate that the change of MNTX plasma concentration versus time is obvious. MNTX level of plasma reaches to a plateau between 45 to 120 minutes and then falls slowly. The content of MNTX in plasma sample maintains at an obviously detectable level after twelve hours of oral administration. The pharmacokinetic parameters for a single dose of 19.2 mg/kg in plasma are c_max=206.42(±16.53) ng/mL and t_max=60 min.

Differentiation of Constitutional Isomer of 2,2a,3,4-Tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide and Fragmentations of 2,3-Dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide

XU Jia-xi, ZUO Gang, LIANG Bo

2005, 21(3):  274-279. 

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Mass spectrometric behaviour of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide and 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. The monooxide derivatives showed a tendency to eliminate an alkene or an oxygen atom. 1H-Azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide could also eliminate the thiophen-2-ylketene molecule via a reverse [2+2] cycloaddition. 2,3-Dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide could eliminate SO₂ or SO, respectively. The structure of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide was identified on the basis of its fragmentation. The identification was supported by the fragmentations of model compound, 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide.

Synthesis, Structure and Biological Activities of 2-(4-Methoxybenzoyl)-N-phenyl-2-(1,2,4-triazol-1-yl)thioacetamide

LIU Fa-qian, QIN Yong-qi, LI Wei-hua, YANG Shuang-hua, LU Lu-de, YANG Xu-jie, WANG Xin, HOU Bao-rong

2005, 21(3):  280-283. 

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The title compound, 2-(methoxybenzoyl)-N-phenyl-2-(1,2,4-triazol-1-yl)thioacetamide was synthesized by several reactions from 4-methoxyacetophenone, triazole and phenyl isothiocyanate. The structure was identified by elemental analysis, ¹H NMR, MS and IR. The single crystal structure of 2-(methoxybenzoyl)-N-phenyl-2-(1,2,4-triazol-1-yl)thioacetamide was determined with X-ray diffraction. The preliminary bioassays show that the title compound exhibits weak antifungal activities and plant-growth regulatory activity.

Hydrothermal Synthesis and Crystal Structure of a Novel Catena Co(Ⅱ) Complex Bridged by Biphenyl-2,2'-dicarboxylate Divalent Anion

MIAO Qian, HU Mao-lin, LI Xin-hua, XIAO Hong-ping

2005, 21(3):  284-286. 

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The title complex, [CO₂(bpdc)₂(bim)₄]_n(bpdc=biphenyl-2,2'-dicarboxylate dianion, bim=benzimidazole), was synthesized in a aqueous solution and its crystal structure was determined by means of X-ray diffraction. There are two different coordinated Co(Ⅱ) centers in the complex. The Co1 center has a deformed trigonal-bipyramidal geometry, while the CO2 center possesses a tetrahedral geometry. In addition, the two different coordination modes of bpdc ligands act as two kinds of bridges to link Co1 and CO2, resulting in a catena chain.

Co-administration of Interleukin-2 Enhances Cellular and Humoral Immune Responses to HIV Vaccine DNA Prime/MVA Boost Regime

JIANG Chun-lai, YU Xiang-hui, WU Yong-ge, LI Wei, KONG Wei

2005, 21(3):  287-290. 

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Interleukine-2(IL-2) is a growth factor for antigen-stimulated T lymphocytes and is responsible for T-cell clonal expansion after antigen recognition. It has been demonstrated that DNA vaccine-elicited immune responses in mice could be augmented substantially by using either an IL-2 protein or a plasmid expressing IL-2. Twenty mice, divided into four experimental groups, were immunized with: (1) sham plasmid; (2) HIV-1 DNA vaccine alone; (3) HIV-1 DNA vaccine and IL-2 protein; or (4) HIV-1 DNA vaccine and IL-2 plasmid, separately. All the groups were immunized 3 times at a 2-week interval. Fourteen days after the last DNA vaccine injection, recombinant MVA was injected into all the mice except those in group 1. ELISA and ELISPOT were employed to investigate the effect of IL-2 on DNA vaccine immune responses. The obtained results strongly indicate that the efficacy of HIV vaccine can be enhanced by co-administration of a plasmid encoding IL-2.

Research on the Role of Rat TPP-Ⅰ in Neuromedin B Degradation

DU Pei-ge, QIU Fang-ping, AN Li-ping, WANG Yan, LU Gang

2005, 21(3):  291-293. 

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TPP-Ⅰ(tripeptidyl peptidase-Ⅰ) protein turnover was studied by observing the role of rat TPP-Ⅰ in neuromedin B(NMB) and other neuropeptides degradations in some physiological situations. The mixtures of rat TPP-Ⅰ with each of NMB, other neuropeptides and Ala-Ala-Phe-MCA were made respectively under the same conditions. The reaction was observed at different timeand monitored by means of high performance liquid chromatography(HPLC) and time-of-flight mass spectrometry(TOF-MS) in vitro. NMB was broken down at the same degree as Ala-Ala-Phe-MCA by rat TPP-Ⅰ and Gly-Asn-Leu was released within 16 h, but other neuropeptides were not digested within 24 h. TPP-Ⅰ is the predominant proteolytic enzyme responsible for the intracellular degradation of neuromedin B. NMB has recently been found to be a good natural substrate for rat lysosomal TPP-Ⅰ.

Purification and Characterization of PRL Protein Tyrosine Phosphatases

LI Zhao-fa, WANG Yan, LI Qing-shan, ZHAO Zhi-zhuang Joe, FU Xue-qi, LI Yu-lin, LI Yi-lei

2005, 21(3):  294-297. 

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PRLs constitute a subfamily of protein tyrosine phosphatases(PTPs). In the present paper are reported the molecular cloning, expression, purification, and characterization of all the three members of the PRL enzymes in human and the only PRL in C.elegans. These enzymes were expressed as glutathione S-transferase(GST) fusion proteins in DE3pLysS E.coli cells, and the recombinant fusion proteins were purified on glutathione-Sepharose affinity columns. Having been cleaved with thrombin, GST-free enzymes were further purified on an S-100 Sepharose gel filtration column. The purified proteins show single polypeptide bands on SDS-polyacrylamide gel electrophoresis. With para-nitrophenyl phosphate(p-NPP) as a substrate, PRLs exhibit classical Michaelis-Menten kinetics with V_max values two orders of magnitude smaller than those of classic PTPs. The responses of PRLs to ionic strength, metal ions and phosphatase inhibitors are similar to those of other characterized PTPs, but their optimal pH values are different. These data thus reveal distinct common biochemical properties of PRL subfamily PTPs as well.

Cloned s-Lap Gene Coding Area, Expression and Localizationof s-Lap/GFP Fusion Protein in Mammal Cells

SONG Yi-shu, SONG Zhi-yu, LI Hong-jun, Wu Yin, BAO Yong-li, TAN Da-peng, LI Yu-xin

2005, 21(3):  298-300. 

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s-Lap is a new gene sequence from pig retinal pigment epithelial(RPE) cells, which was found and cloned in the early period of apoptosis of RPE cells damaged with visible light. We cloned the coding area sequence of the novel gene of s-Lap and constructed its recombinant eukaryotic plasmid pcDNA3.1-GFP/s-lap with the recombinant DNA technique. The expression and localization of s-lap/GFP fusion protein in CHO and B₁₆ cell lines were studied with the instantaneously transfected pcDNA3.1-GFP/s-lap recombinant plasmid. s-Lap/GFP fusion protein can be expressed in CHO and B₁₆ cells with a high rate expression in the nuclei.

Influence of Apoptin on Up-regulation of the Expression of Bad and Bax

GUO Tai, YANG Qian

2005, 21(3):  301-305. 

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The chicken anemia virus protein, apoptin, which manifests selectivity and specificity to tumor cells, induces a p53-independent and Bcl-2-insensitive type of apoptosis in various human tumor cells. In this study, the apoptin gene was cloned from the total DNA of chicken anemia virus, and the recombinant vector was constructed. We used oligonucleotide microarray to study the changes of four genes, including Bcl-2, Bcl-xL, Bad and Bax. The post-transfection with the recombinant was also studied. The pro-apoptotic genes(Bad and Bax) and anti-apoptosis genes(Bcl-2 and Bcl-xL) were up-regulated in contrast to the controls. According to the published data, either Bcl-2 or Bcl-xL can form non-functional heterodimers by Bad and Bax binding together, resulting in blocking partly the release of cytochrome c from mitochondria. However, apoptosis could be inhibited by neither the endogenous Bcl-xL nor Bcl-2 over-expression. The experiments show that the apoptin-induced apoptotic pathway is related to the up-regulation of Bad and Bax. Bad was up-regulated by apoptin; then this up-regulated product of Bad was in favor of displacing Bax from binding to Bcl-xL or Bcl-2. Consequently, Bax exerted a pro-apoptotic dysfunction to mitochondria, thereby inducing the release of cytochrome c. Finally, apoptin induced the apoptosis of HHCC cells. These results indicate that the oligonucleotide microarray can reveal the genes related to the apoptosis induced by apoptin in HHCC cells.

Structure Analysis of Pectin SB_1-1 from the Root of Panax ginseng

TIAN Mei-hong, WEI Min, ZHANG Li-ping, LIANG Zhong-yan

2005, 21(3):  306-308. 

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A water-soluble pectin SB_1-1 was isolated and purified from the root of Panax ginseng C. A. Mey. The HPLC analysis indicates that SB_1-1 is homogenous. Its molecular weight was estimated via gel filtration to be 10000. The GC analysis indicated that it contains the monosaccharides of GalA, Gal, Ara and Rha. Their molar ratio is 2.10∶1.00∶0.12∶0.13. Partial hydrolysis with acid, pectinase treatment, periodate oxidation, Smith degradation, methylation analyses, GC/MS analyses and NMR analyses were used for the structure analyses of SB_1-1. The results reveal that SB_1-1 has a lower branched structure. The main chain is composed of GalA and Gal; the inner part is α-1,4-linked-GalA; the border is 1,4-linked-Gal. Some of the 1,4-linked-GalA and 1,4-linked-Gal residues are substituted at O6. On an average, there is one branch for every ten hexose residues. The side chain is composed of 1,6-linked-Gal and 1,3,6-linked-Gal. The nonreduced end is composed of Rha, Ara and Gal. The main glycosidic link of SB_1-1 has an α configuration.

PAM Templating Mechanism for Synthesis of A Novel LiFePO₄ Cathode Material

YANG Shu-ting, ZHAO Na-hong, DONG Hong-yu, YUE Hong-yun, YANG Jin-xin

2005, 21(3):  309-314. 

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A novel templated LiFePO₄ cathode material was prepared with linear polyacrylamide, which exhibited excellent electrochemical properties, such as a 109.3 mA·h/g capacity at a rate of C/3 and a 120 mA·h/g capacity at a rate of C/6 as well as a good cycliability. We proposed the templating mechanism based upon the precursors' TG-DTA curves, X-ray diffraction patterns and FTIR spectra of the samples at different temperatures. A tapping-mode atomic force microscope was used to investigate the surfaces of the end products. We found that the polyacrylamide template produced metal organic compounds in the cross-linked gel precursor, and thereby modified the crystallization and particle surfaces during calcining. The template was "removed" in the end, which was partially pyrolyzed into the spiral carbon to form a conductive network with nanocrystalline LiFePO₄ highly monodispersed in it.

Electrolessly Plated Ni-Zn(Fe)-P Alloy and Its Corrosion Resistance Properties

WANG Sen-lin, WU Hui-huang

2005, 21(3):  315-321. 

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The autocatalytic deposition of Ni-Zn(Fe)-P alloys has been carried out on substrate of carbon steel from a bath containing nickel sulfate, zinc sulfate, sodium hypophosphite, sodium citrate and boric acid. The effects of pH and the molar ratio of NiSO₄/ZnSO₄ on the deposition rate and the composition of deposits have been studied. It was found that the presence of zinc sulfate in the bath has an inhibitory effect on the alloy deposition. The structure and the surface morphology of Ni-Zn(Fe)-P coatings were characterized with XRD and SEM, respectively. The alloys plated under the experimental conditions consisted of an amorphous phase coexisting with a crystalline cubic Ni phase(poly-crystalline). The surface morphology of the coating is dependent on the deposition parameters. The corrosion resistance of the Ni-Zn(Fe)-P deposits was examined via mass loss tests and anodic polarization measurements, respectively. The results show that the surface morphologies of the deposits and the corrosion resistance of the deposits have been improved. The results of mass loss tests almost accord with those of anodic polarization measurements. The corrosion mechanisms of Ni-Zn(Fe)-P alloys in NaCl and NaOH solutions were investigated by means of EDX. The deposit immersed in an NaCl or an NaOH solution contains more content of oxygen and less contents of the metals(except Fe) than that placed in air, which shows that the NaCl or NaOH solution can accelerate the oxidation of the deposit.

Electrochemical Oxidation of L-Cystenine in SDS/BA/H₂O Microemulsion

LI Zhong-chun, LIU Tian-qing, GUO Rong

2005, 21(3):  322-325. 

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The electrochemical oxidation of L-cysteine in an SDS/BA/H₂O microemulsion system was studied with the methods of ultramicroelectrode cyclic voltammetry and AC impedance. The catalytic efficiency of the microemulsion on the electrochemical oxidation increases with the increase of BA or SDS content, but decreases with the increase of the water content because of the effects of BA, SDS and water on the solubilization of L-cysteine in the microemulsion. Furthermore, the catalytic efficiency of the bicontinuous structure is greater than that of an O/W microemulsion system. The results derived from both the rate constant k⁰ and Gibbs free energy ΔG^≠ accord with those from the catalytic efficiency.

Catalytic Oxidative Conversion from Naphthol to 2-Hydroxy-1, 4-naphthoquinone over Iron Porphyrin Catalysts by Molecular Oxygen in an Alkaline 2-Propanol Solution

YANG Ke-er, TONG Shan-ling, YAN Yan, KANG En-hua, XIAO Feng-shou, LI Qing, CHANG Xin, FANG Chi-guang

2005, 21(3):  326-333. 

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In an alkaline 2-propanol solution with 5,10,15,20-tetra(4-methoxyl phenyl) porphyrin iron chloride(TOMPPFeCl) as a catalyst and oxygen as a cheap green oxidant, 2-naphthol was conversed to 2-hydroxy-1,4-naphthoquinone(HNQ) with a yield of 62.17% and a selectivity of 100%, and the conversion number of TMOPPFeCl catalyst was 8.32/min. The catalytic oxidation products were characterized by means of UV-Vis, IR, GC-MS, ¹H NMR and melting point determination. In this catalytic oxidation, the catalytic activity of TMOPPFeCl was researched in detail and the reacting conditions were optimized. A possible reaction mechanism is summarized based on in situ EPR determination.

Dispersion of Polyacenic Semiconductor(PAS) in Polyethylene: Molecular Dynamics Simulation

SUN Hai-zhu, SHAO Chen, HU Dong-hua, ZU Long-min, SU Zhong-min, ZHU Yu-lan

2005, 21(3):  334-336. 

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The dispersing process of polyacenic semiconductor(PAS) in polyethylene(PE) was simulated by using molecular dynamics(MD) methods. The results show that this process can be divided into three stages. In the first stage, PAS particles in the crystal region of PE are expelled to the amorphous region; in the second stage, PAS particles aggregate due to small surface areas and PE chains are adjusted continuously, which makes the crystal region complete; PAS particles are separated from each other and the total energy increases in the third stage. During the whole dispersing process, PAS particles are more stable in the amorphous region than in the crystal region. All the simulation results are in good agreement with the experimental results.

Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

DENG Qi-gang, YU Hong-wei, LIN Hong, JIA Li-hua, GUO Xiang-feng, ZHOU De-rui

2005, 21(3):  337-339. 

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Four gemini cationic surfactants {N,N'-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ¹H NMR, ¹³C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

Synthesis and Characterization of ABBA Block Copolymer of Glycolide and ε-Caprolactone

CHEN Li, CHEN Xue-si, DENG Ming-xiao, JING Xia-bin

2005, 21(3):  340-344. 

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A biodegradable ABBA block copolymer was synthesized via the ring-opening co-polymerization of ε-caprolactone(CL, B) and glycolide(A) by means of step polymerization in the presence of ethylene glycol as an initiator and stannous octanoate as a catalyst at 110 ℃ for 48 h. The molecular length of the PCL pre-polymer(BB) could be adjusted by controlling the molar ratio of the ethylene glycol initiator to ε-caprolactone monomer. The structure and the composition of the block copolymer were determined by the weight ratio of the monomer glycolide(A) to PCL pre-polymer(BB). The block copolymers were characterized by ¹H NMR, GPC, DSC and X-ray. The results confirm the successful synthesis of an ABBA block copolymer.

Aliphatic Hyperbranched Poly(amido amine)s(PAMAMs): Preparation and Modification

LIU Cui-hua, GAO Chao, YAN De-yue

2005, 21(3):  345-354. 

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A series of water soluble aliphatic hyperbranched poly(amido amine)s(PAMAMs) with the same or similar chemical structure of poly(amido amine) dendrimer was successfully synthesized from commercially available AB and C_n types of monomers by one-pot polymerization via the couple-monomer methodology(CMM). The AB type monomer used in this paper was methyl acrylate, and C_n monomers were multi-amino compounds such as ethylenediamine(EDA), diethylenetriamine(DETA), triethylenetetraamine(TETA), tetraethylenepentaamine(TEPA) and pentaethylenehexamine(PEHA). The reaction mechanism was investigated by means of the mass spectra of the reaction intermediates. Adjusting the feed ratio of AB to C_n, hyperbranched polymers with different terminal groups and properties were obtained. FTIR, NMR, DSC, and TGA were used to characterize the polymers. It was found that the polymers' properties such as solubility, thermal behaviour and encapsulation capability varied with changing the feed ratio of AB to C_n. Benzoyl and palmitoyl groups were introduced into these macromolecules by acidylation to form amphiphilic hyperbranched polymers which have a high capability to encapsulate water soluble dyes such as Congo red. It is expected that the hyperbranched PAMAMs can play an important role in the industrial applications, such as coatings, cross-linking and phase-transferring agents because of their versatility and availability.

Syntheses and Surface Properties of Polyacrylonitrile-based Copolymer Membranes Containing Sugar Moieties

HUANG Xiao-jun, WAN Ling-shu, DAI Zheng-wei, KOU Rui-qiang, XU Zhi-kang

2005, 21(3):  355-359. 

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To improve the hydrophilicity of polyacrylonitrile-based membranes, sugar moieties were incorporated into acrylonitrile-based copolymers via the radical copolymerization of α-allyl glucoside(AG) with acrylonitrile(AN) with 2,2'-azobis-iso-butyronitrile(AIBN) as the initiator in dimethyl sulphoxide(DMSO). It was found that the yield increased with the increase of the initiator concentration and reaction time, while it decreased with the increase of the monomer molar ratio of AG to AN. Raising the AG proportion in the monomer mixture resulted in the increase of the AG content in the copolymer. M_v of the copolymers decreased with increasing the AG monomer fraction in feed. The copolymers were fabricated into dense membranes and their surface properties were studied by means of the water contact angle measurement and platelet adhesion tests. It was found that the static water contact angle on the membrane decreased significantly from 70° to 33° with the increase of the AG content. The adhesive number of platelets on the membrane surface also decreased significantly with increasing AG content in the copolymers. These results demonstrate that the hydrophilicity and biocompatibility of the acrylonitrile-based copolymer membranes could be improved efficiently by the copolymerization of acrylonitrile with vinyl carbohydrates.

Photocurrent of TiO₂ Photoelectrode Enhanced by Nafion Modification

PAN Kai, LIU Zhao-yue, HU Jian-qiang, LI Jun, LI Zi-heng, LI Di, LIU Yang, LIU Min, LI Jing-hong, WANG De-jun, BAI Yu-bai, LI Tie-jin

2005, 21(3):  360-364. 

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Two Novel Copper(Ⅱ) Complexes with A Novel Ligand 2,4-Di(2-aminopyridine)-6-methylpyrimidine

MA Hai-rui, WANG Yao-yu, LIU Ping, LI Dong-sheng, SHI Qi-zhen, LEE Gene-hsiang, PENG Shie-ming

2005, 21(3):  365-367. 

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Hydrothermal Synthesis and Crystal Structure of a Highly Reduced Mixed Molybdenum-vanadium Polyoxometalate with Phosphorus-centered [Ni(phen)₃]2H₂·[Pmo₄^ⅤMo₄^ⅥV₆^ⅣM₂M₄₄]^5-·4H₂O(M=0.78Mo^Ⅴ+0.22V^Ⅳ)

SUN Ying-hua, DING Hong, XU Ji-qing, LI Yong, LI Guang-hua

2005, 21(3):  368-371. 

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A Concise and Stereoselective Synthesis of Cathasterone's Side Chain

MEI Tian-sheng, LU Li, LIU Hua-wei, PENG Li-zeng, ZANG Tao, LI Yu-lin

2005, 21(3):  372-375. 

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New Fragmentation Pathways for Cephalosporins by Electrospray Ionization Quadrupole Time-of-flight Mass Spectrometry

WANG Ying-wu, GU Jing-kai, J. Paul Fawcett, ZHONG Da-fang, ZHOU Hui

2005, 21(3):  376-379. 

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