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ADVANCES IN MICROEMULSION PHASE ON SELF-ASSEMBLY AND MICELLE EXTRACTION WITH BLOCK COPOLYMERS

China Particuology 2005年第6期3卷 310-316页

作者： Chen Guo Hao Wen Huizhou Liu Lahoratory of Separation Science and Engineering State Key Laboratory of Biochemical EngineeringInstitute of Process EngineeringChinese Academy of Sciences.P.O.Box 353Beijing 100080P.R.China

In this paper we review our work on self-assembly of the system, poly（ethylene oxide）-poly（propylene oxide）-poly（elhylene oxide）（PEO-PPO-PEO） block copolymers, which is a kind of macromolecular complex fluids. The control of self-assembly could be obtained by adding inorganic salts or aliphatic alcohols. By self-assembly of amphiphilic block copelymers a microemulsion phase is formed which could be applied in micelle extraction, such as hollow-fiber membrane micelle extraction, magnetic micelle extraction and immobilized micelle extraction.

关键词： microemulsion phase self-assembly block copolymer extraction

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Fabrication of silica colloidal crystal multilayer with controlled thicknesses by vertical deposition

Fabrication of silica colloidal crystal multilayer with cont...

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作者： Li, Qunyan Gao, Weimin Chen, Yunfa Dong, Peng Wu, Zhenjiang Multiphase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China State Key Laboratory of Heavy Oil Processing University of Petroleum Beijing 102200 China

The silica colloidal crystal multilayers were deposited from ethanol suspensions with different particle concentrations by vertical deposition method. The microstructures and thicknesses of silica colloidal multilayers were characterized by scanning electron micrography. The thicknesses of colloidal crystal multilayers increased with the particle concentration increasing within a certain range of particles concentrations. When the particle concentration exceeded 2.48wt%, the thicknesses of colloidal crystal multilayers didn't increased with the concentration increasing. Colloidal crystal multilayers with few defects could be deposited from the suspensions with the particle concentration 2.48wt%. The optical properties of the silica colloidal multilayers were investigated by a UV-Vis scanning spectrophotometer in normal incidence. They corresponded well to the microstructure obtained by SEM images.

关键词： Silica

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Suitability of Steric Mass-action Model for Ion-exchange Equilibrium of Micromolecule

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Chinese Journal of Chemical engineering 2005年第1期13卷 18-23页

作者：陈卫东王艳东苏志国 Department of Biochemical Engineering School of Chemical Science and Engineering University of Petroleum China (Beijing) Beijing 102249 China Institure of Molecular Radiobiology GSF Ingolstadtr. 1 D-85764 Neuherberg Germany State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

The steric mass-action (SMA) model has been widely reported in the literature for ion-exchange and metal-affinity interaction adsorption equilibrium of biomacromolecules. In this paper, the usefulness of SMA model is analyzed for describing micromolecule ion-exchange equilibrium onto cation exchangers, CM Sephadex C-25 and Streamline SP. Batch adsorption experiments with ephedrine hydrochloride as a model adsorbate are carried out to determine the model parameters, that is, steric factor, characteristic charge and equilibrium constant. The result shows that the SMA model parameters of micromolecule cannot be obtained using the nonlinear least-square fitting method as protein's due to the remarkable difference between the molecular mass and dimension of micromolecule and protein. It is considered that the small size of the adsorbates dealt with in this study justifies the neglect of steric hindrances arising from adsorbate bulkiness. Thus, the three-parameter SMA model is reduced to two-parameter one (i.e., steric factor is equal to zero) for describing micromolecule ion-exchange equilibrium. It is found that the equilibrium constant for CM Sephadex C-25 increases with increasing ionic strength, while the equilibrium constant for Streamline SP shows an opposite trend. This is probably due to the remarkable difference between the physicalpro perties of the two adsorbents. Then, the relationship between the equilibrium constant and ionic strength is described by an expression. The computer simulations show that, the theoretical model with the correlation is promising in the prediction of micromolecule adsorption decrease with increasing ionic strength in a wide range of salt concentration.

关键词： micromolecule ion-exchange equilibrium steric mass-action model chromatography

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AtHsfA2 modulates expression of stress responsive genes and enhances tolerance to heat and oxidative stress in Arabidopsis

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Science China(Life Sciences) 2005年第6期48卷 540-550页

作者： LI Chunguang1,2, CHEN Qijun1, GAO Xinqi1,3, QI Bishu1, CHEN Naizhi1, XU Shouming1, CHEN Jia1 & WANG Xuechen1 1. state key laboratory of Plant Physiology and biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China 2. Department of Industry engineering, Zhengzhou institute of Aeronautic Industry Management, Zhengzhou 450015, China 3. College of Life Science, Qufu Normal University, Qufu Shandong 273165, China 1. State Key Laboratory of Plant Physiology and Biochemistry College of Biological Sciences China Agricultural University 100094 Beijing China 2. Department of Industry Engineering Zhengzhou Institute of Aeronautic Industry Management 450015 Zhengzhou China 3. College of Life Science Qufu Normal University 273165 Qufu Shandong China

There is increasing evidence for considerable interlinking between the responses to heat stress and oxidative stress, and recent researches suggest heat shock transcription factors (Hsfs) play an important role in linking heat shock with oxidative stress signals. In this paper, we present evidence that AtHsfA2 modulated expression of stress responsive genes and enhanced tolerance to heat and oxidative stress in Arabidopsis. Using Northern blot and quantitative RT-PCR analysis, we demonstrated that the expression of AtHsfA2 was induced by not only HS but also oxidative stress. By functional analysis of AtHsfA2 knockout mutants and AtHsfA2 overexpressing transgenic plants, we also demonstrated that the mutants displayed reduced the basal and acquired thermotolerance as well as oxidative stress tolerance but the overexpression lines displayed increased tolerance to these stress. The phenotypes correlated with the expres-sion of some Hsps and APX1, ion leakage, H2O2 level and degree of oxidative injuries. These results showed that, by modulated expression of stress responsive genes, AtHsfA2 enhanced tolerance to heat and oxidative stress in Arabidopsis. So we suggest that AtHsfA2 plays an im-portant role in linking heat shock with oxidative stress signals.

关键词： heat shock transcription factor, heat stress response, oxidative stress response, tolerance.

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Improving the quality of 3D-QSAR by using flexible-ligand receptor models

Improving the quality of 3D-QSAR by using flexible-ligand re...

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作者： Pei, Jianfeng Chen, Hao Liu, Zhenming Han, Xiaofeng Wang, Qi Shen, Bin Zhou, Jiaju Lai, Luhua State Key Laboratory for Structural Chemistry of Stable and Unstable Species College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Center for Theoretical Biology Peking University Beijing 100871 China Computer Network Information Center Chinese Academy of Sciences Beijing 100080 China Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

To address the problems associated with molecular conformations and alignments in the 3D-QSAR studies, we have developed the Flexible Ligand - Atomic Receptor Model (FLARM) 2.0 method. The FLARM 2.0 method has three unique features as compared to other pseudoreceptor model methods: (1) the training ligands are flexibly optimized inside the receptors to achieve minimal docking energies;(2) the receptor atoms are spatially moveable in the process of genetic evolving in order to avoid improper initial receptor shapes;and (3) void receptor sites are specially favored in order to obtain open receptor models that allow large gaps. Advantages of an open model include less noise information, a smaller risk of overfitting, and ease of locating the key interaction sites. The latter two features, inherited from the previous FLARM 1.0 method, can improve the predictive ability of the 3D-QSAR models, while the first feature is newly implemented to relieve the uncertainty caused by improper conformation and alignment. Three FLARM 2.0 case studies were performed, and the results show that FLARM 2.0 models are highly predictive and robust. FLARM 2.0 pseudoreceptor models can correspond well with the pharmacophore models and/or the binding sites of the real protein receptors. © 2005 American Chemical Society.

关键词： Molecular dynamics

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Recovery of Butyl Acetate in Wastewater of Penicillin Plant by Solvent Sublation II. Theoretical Modeling

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Separation Science & Technology 2005年第4期40卷 941-957页

作者： Xinghua Sun Zhidong Chang Huizhou Liu Reniong Gao Laboratory of Separation Science and Engineering. State Key Laboratory of Biochemical Engineering. Institute of Process Engineering. Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Beijing. P. R. China. North China Pharmaceutical Corporation Limited Shijiazhuang. P. R. China

In recent years, pilot-scale solvent sublation has been explored in the treatment of industrial wastewater containing dilute organics. In the present work, a mathematical model is proposed to describe the experimental results of semibatch sublation for recovering butyl acetate (BA) in the wastewater from solvent extraction of penicillin. Different from other models in recent literatures, our model took account of the variation of the volume of solvent, vo,, in the sublation. The model parameters of the sublation of BA in the wastewater are calculated. Calculation results show the volume of solvent could increase by more than 30% in 180 min under optimal conditions. Calculation results with different operation parameters show that increasing the gas flow rate, Qa, could improve the sublation efficiency, Ess, which would be more than 70% under optimal conditions. Decreasing the bubble size, a, would increase the rate of the sublation. The initial solvent volume, voi, may affect the sublation weakly when initial ratio of water to solvent used is in the range from 50 to 70. Calculation results also show that the loss of butyl acetate to the atmosphere, Els is minimal, though with high gas flow rate. The simulated results are in good agreement with experimental results. [ABSTRACT FROM AUTHOR]

关键词： butyl acetate mathematical model penicillin Solvent sublation wastewater

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Selection of phospholipase A2 by Using Ribosome Display#

Selection of phospholipase A2 by Using Ribosome Display#

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第四届全国化学生物学学术会议暨国际化学与生物/医学交叉研讨会

作者：刘莹黄常康来鲁华 Frank Kuppler VolkerA．Erdmann State Key Laboratory for Structural Chemistry of UnstableandStableSpecies Institute of Physical Chemistry&College of Chemistry and Molecular Engineering Peking University Beijing Institute of Biochemistry Free University Berlin Thielallee63 14195Berlin Germany State Key Laboratory for Structural Chemistry of Unstableand Stable Species Institute of Physical Chemistry&College of Chemistry and Molecular Engineering PekingUniversity Beijing State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Physical Chemistry&College of Chemistry and Molecular Engineering PekingUniversity Beijing Institute of Biochemistry FreeUniversity Berlin Thielallee63 14195Berlin Germany Institute of Biochemistry Free University Berlin Thielallee63 14195Berlin Germany

High levels of PLA2 are observed in a variety of severe inflammatory diseases and have been considered to be accountable for some inflammatory reactions. Thus, the inhibitors of PLA2 would have great potential for the... 详细信息

关键词： Selection of phospholipase A2 by Using Ribosome Display

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Influencing factors on Ni bioaccumulation by Synechcoccus

Beijing Keji Daxue Xuebao/Journal of University of Science a...

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Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing 2005年第5期27卷 528-531页

作者： Bai, Huiqing Du, Zhuwei Li, Haoran Sun, Chunbao Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

Influencing factors on Ni bioaccumulation by Synechcoccus were studied. The equilibration time of Ni bioaccumulation was about 80 min in aqueous solution. The bioaccumulation quantity reached a maximum when the mass ratio of Ni to Synechcoccus was between 16%-18%, and increased with the increasing of pH. The optimum pH was 9-10 because high pH would lead to precipitation of Ni(OH)2. The bioaccumulation quantity was also influenced by temperature and illumination intensity and the optimal condition was 35°C and 3000 lx. The bioaccumulation of nonliving algae was lager than that of living algae.

关键词： Water pollution control

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Preparation and surface modification of magnetic poly(methyl methacrylate) microspheres

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Science China Chemistry 2004年第4期47卷 349-354页

作者： YANG Chengli GUAN Yueping XING Jianmin LIU Junguo AN Zhentao LIU Huizhou Laboratory of Separation Science and Engineering State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of Sciences Beijing 100080 China

A novel method for preparation of magnetic polymer microspheres by spraying suspension polymerization (SSP) was developed. Relatively uniform magnetic poly(methyl methacrylate) microspheres were prepared by the spraying suspension polymerization (SSP) using methyl methacrylate (MMA) as monomer, divinylbenzene (DVB) as cross-linking agent, benzoyl peroxide (BPO) as initiator and polyvinyl alcohol (PVA) as stabilizer in the presence of hydrophobic Fe3O4 magnetic fluid. The microspheres prepared were modified by surface chemical reaction. The magnetic properties and morphology of the microspheres were examined by SEM and VSM respectively. The active functional groups of microspheres were examined by infrared spectra. The results showed that microspheres with saturation magnetization of 16.8 emu/g showed distinct superparamagnetic characteristics and the magnetic microspheres with a size of 10 μm were relatively uniform.

关键词： methylmethacrylate superparamagnetic spraying suspension polymerization surface modification preparation characterization

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Enzymatic Synthesis and Biological Effect of Unsaturated Fatty Acid Ester of L-Ascorbic Acid

Enzymatic Synthesis and Biological Effect of Unsaturated Fat...

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The Eighth China-Japan-Korea Joint Symposium on Enzyme engineering

作者： Qing-Xun Song Dong-Zhi Wei Ying Zhao Wei-Qin Xu State Key Laboratory of Bioreactor Engineering Institute of BiochemistryEast China University of Science and Technology

L-ascorbic acid and its derivatives have attracted considerable attention in recent years for preventing oxidative stress related *** of L-ascorbic acid via esterification or transesterification with aliphatic molecules,such as fatty acids,is a useful way to alter solubility in oil-based formulae and emulsion.L-ascorbyl derivatives such as L-ascorbyl laurate and L-ascorbyl palmitate were synthesized using immobilized *** fatty acid have more beneficial effects on human than saturated fatty *** an alternative substitute of saturated fatty acid,more attention is being focused on the synthesis of unsaturated fatty acid ester of L-ascorbic acid,such as L-ascorbyl oleate and L-ascorbyl linoleate.L-Ascorbyl oleate and L-ascorbyl linoleate were successfully prepared by enzymatic esterification and transesterification in a non-aqueous medium using immobilized lipase as *** in enzymatic activity and product yield were studied for the following variable:solvent,the nature of the fatty acid,the fatty acid concentration,water *** kinetic model was discussed and the result showed that the reaction could be described by ping-pong *** parameters values of V' and K' were *** product maximum yield（42.9%） in the transesterification was higher than that of the esterification（21.2%）at substrate concentration 0.11 ***,the presence of water and methanol byproduct limited the reaction to shift towards the *** improve the synthesis yield,the means of removing water and methanol byproduct has been taken into account,and designed a reactor for elimination of water and methanol byproduct.A single purification procedure enabled the product to be obtained at purity above 93%（w/w）.Structure analysis later demonstrated that linoleic acid was exclusively incorporated into the L-ascorbic acid *** study of protective effects on human umbilical cord vein endothelial cells（ECV-304） treated with HO

关键词： ECV Enzymatic Synthesis and Biological Effect of Unsaturated Fatty Acid Ester of L-Ascorbic Acid

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