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A pH-and temperature-sensitive macrocyclic graft copolymer composed of PEO ring and multi-poly(2-(dimethylamino) ethyl methacrylate) lateral chains

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science china Chemistry 2010年第8期53卷 1653-1662页

作者： PANG XinChang,JING RongKuan,PAN MuGang & HUANG JunLian key laboratory of molecular engineering of polymers,Ministry of Education department of macromolecular science,fudan university,shanghai 2..433,china 1. key laboratory of molecular engineering of polymers Ministry of Education department of macromolecular science Fudan University Shanghai 200433 China

A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxyl poly(ethylene oxide) with pendant acetal protected hydroxyl groups (l-poly(EO-co-EEGE)) was prepared first by the anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE).Then l-poly(EO-co-EEGE) was *** crude cyclized product containing the linear byproduct was hydrolyzed and purified by being treated with α-*** pure cyclic copolymer [c-poly(EO-co-Gly)] was esterified by reaction with 2-bromoisobutyryl bromide,and then used as ATRP macroinitiators to initiate polymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA),and a series of pH-and temperature-sensitive macrocyclic graft copolymers composed of a hydrophilic PEO as the ring and PDMAEMA as side chains (c-PEO-g-PDMAEMA) were *** behavior of pH-and temperature-sensitive macrocyclic copolymers was studied in aqueous solution by fluorescence and dynamic light scattering (DLS).The critical micellization pH values of macrocyclic graft copolymers and their corresponding linear graft copolymers (l-PEO-g-PDMAEMA) were *** the same conditions,the cyclic graft copolymer with the shorter side chains gave the higher critical micellization pH *** c-PEO-g-PDMAEMA showed the lower critical micellization pH value than the corresponding *** average hydrodynamic diameters (Dh) of the micelles were measured by DLS with the variation of the aqueous solution pH value and temperature.

关键词： macrocyclic PEO anionic ring-opening polymerization ATRP PDMAEMA pH-and temperature-sensitive

维普期刊数据库

Dynamics of Primary Events in the Photocycle of Excited Bacteriorhodopsin

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Acta Biochimica et Biophysica Sinica 2004年第11期36卷 724-728页

作者： Jun-Jun LU, Ming MING, Yi YANG, Jia WU, Bo LI, Jian-Dong DING, Qing-Guo LI, and Shi-Xiong QIANdepartment of Physics, fudan university, shanghai 2..433, china department of macromolecular science, key laboratory of molecular engineering of polymers, fudan university, shanghai 2..433, china department of Physiology and Biophysics, School of Life sciences, fudan university, shanghai 2..433, china department of Physics Fudan University Shanghai 200433 China

Transient dynamic behavior of the excited bacteriorhodopsin (BR), which was isolated from the strain H. salinarum, was studied at excitation wavelength from 585 to 639 nm. With the one-color femtosecond (fs) pump-probe technique, we revealed the primary events in BR's photocycle that took place in an ultrafast time scale. From the analysis of the decay components of the dynamical traces, it was evident that the isomerization of the retinal

关键词： bacteriorhodopsin transient dynamics primary events femtosecond laser pump-probe technique

PEG-g-poly(aspartamide-co-N,N-dimethylethylenediamino aspartamide):Synthesis,characterization and its application as a drug delivery system

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Progress in Natural science:Materials International 2009年第10期19卷 1305-1310页

作者： Dong Yang,Xiaohong Zhang,Li Yuan,Jianhua Hu key laboratory of molecular engineering of polymers(Ministry of Education),laboratory of Advanced Materials,department of macromolecular science,fudan university,shanghai 2..433,china [a]key laboratory of molecular engineering of polymers (Ministry of Education) Laboratory of Advanced Materials Department of Macromolecular Science Fudan University Shanghai 200433 China

PEG-g-poly(aspartamide-co-N,N-dimethylethylenediamino aspartamide)(PEG-DMEDA-PASP) was synthesized by two-step ring-opening reactions of polysuccinimide(PSI) with a-methoxy-x-amino-poly(ethylene glycol) and N,*** polymer structure was confirmed by 1H NMR and *** resultant PEG-DMEDA-PASP with ammonium glycyrrhizinate(AMG) could form polymeric micelles in aqueous *** results of transmission electron microscopy(TEM) and dynamic light scattering(DLS) measurements revealed that these polymeric micelles were spherical particles with a narrow diameter distribution and that their average diameter was ca.70 *** polymeric micelles had high-loading capacity(58%) and encapsulation efficiency(70%) for *** results of in vitro release experiments showed that these polymeric micelles possessed sustained-release effects,with a release rate of 25% within 3 h and 90% within 24 h.

关键词： PEG-g-poly(aspartamide-co-N,N-dimethylethylenediamino aspartamide) Polymeric micelle Drug delivery system Ammonium glycyrrhizinate

Preparation of water-soluble multi-walled carbon nanotubes by Ce(IV)-induced redox radical polymerization

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Progress in Natural science:Materials International 2009年第8期19卷 991-996页

作者： Dong Yang, Xiaohong Zhang, Changchun Wang, Yuechao Tang, Junjun Li, Jianhua Hu key laboratory of molecular engineering of polymers (Ministry of Education) and department of macromolecular science, fudan university, shanghai 2..433, china [a]key laboratory of molecular engineering of polymers (Ministry of Education) and department of macromolecular science Fudan University Shanghai 200433 China

Poly(acrylic acid), poly(N-isopropylacrylamide) and polyacrylamide functionalized MWNTs were prepared by Ce(IV)-induced redox radical polymerization. The reaction can be conducted in aqueous media at room temperature, and the polymer graft ratio increased with the increase of monomer feed ratio. MWNTs anchored with PAA on the surface are pH sensitive and exhibit a reversible assembly–deassembly response in aqueous solution, whereas those coated with PNIPAM are thermally sensitive. All the polymer-functionalized MWNTs are highly soluble in water to give robust stable black solutions. Such water-soluble MWNTs are promising for biological and biomedical applications.

关键词： Carbon nanotube Redox polymerization Water solubility Stimuli response

Miktoarms hyperbranched polymer brushes:One-step fast synthesis by parallel click chemistry and hierarchical self-assembly

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science china Chemistry 2010年第12期53卷 2461-2471页

作者： HAN Yi & GAO Chao MOE key laboratory of macromolecular Synthesis and Functionalization department of Polymer science and engineering,Zhejiang university,Hangzhou 310027,china 1. MOE key laboratory of macromolecular Synthesis and Functionalization department of Polymer science and engineering Zhejiang University Hangzhou 310027 China

Spherical molecular brushes with amphiphilic heteroarms were facilely synthesized by grafting the arms of hydrophobic 2-azidoethyle palmitate and hydrophilic monoazide-terminated poly(ethylene glycol) onto the core of alkyne-modified hyperbranched polyglycerol (HPG) with high molecular weight (Mn=122 kDa) via one-pot parallel click *** parallel click grafting strategy was demonstrated to be highly efficient (～100%),very fast (～ 2 h) and well controllable to the amphilicity of molecular *** adjusting the feeding ratio of hydrophobic and hydrophilic arms,a series of brushes with different arm ratios were readily *** resulting miktoarms hyperbranched polymer brushes (HPG-g-C16/PEG350) were characterized by hydrogen-nuclear magnetic resonance (1H NMR),Fourier transform infrared (FT-IR) spectroscopy,gel permeation chromatography (GPC),and differential scanning calorimetry (DSC) *** spherical molecular brushes showed high molecular weights up to 230 kDa,and thus could be visualized by atomic force microscopy (AFM).AFM and dynamic laser light scattering (DLS) were employed to investigate the self-assembly properties of amphiphilic molecular brushes with closed proportion of hydrophobic and hydrophilic *** brushes could self-assemble hierarchically into spherical micelles,and network-like fibre structures,and again spherical micelles by addition of n-hexane into the dichloromethane or chloroform solution of *** addition,this kind of miktoarms polymer brush also showed the ability of dye loading via host-guest encapsulation,which promises the potential application of spherical molecular brushes in supramolecular chemistry.

关键词： miktoarms molecular brushes hyperbranched polyglycerol amphiphilic self-assembly

维普期刊数据库

Identification and Characterization of glnA Promoter and its Corresponding Trans-regulatory Protein GlnR in the Rifamycin SV Producing Actinomycete,Amycolatopsis mediterranei U32

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Acta Biochimica et Biophysica Sinica 2006年第12期38卷 831-843页

作者： Hao YU~(1&) Wen-Tao PENG~1 Yang LIU~1 Ting WU~2 Yu-Feng YAO~1 Ming-Xue CUI~1 Wei-Hong JIANG~1 Guo-Ping ZHAO~(1,3,4*) 1 laboratory of molecular Microbiology,Institute of Plant Physiology and Ecology,shanghai Institutes for Biological sciences,Chinese Academy of sciences,shanghai 200032,china 2 department of Medicinal Chemistry,School of Pharmacy,fudan university,shanghai 200032,china 3 State key laboratory of Genetic engineering & department of Microbiology,School of Life science,fudan university,shanghai 2..433,china 4 laboratory of Disease and Health Genomics,Chinese National Human Genome Center at shanghai,shanghai 201203,china laboratory of molecular Microbiology Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200032 China department of Medicinal Chemistry School of Pharmacy Fudan University Shanghai 200032 China State key laboratory of Genetic engineering & department of Microbiology School of Life Science Fudan University Shanghai 200433 China laboratory of Disease and Health Genomics Chinese National Human Genome Center at Shanghai Shanghai 201203 China

The genetic requirements for the transcription of glnA,encoding the major glutaminesynthetase in a rifamycin SV-producing Amycolatopsis mediterranei strain,U32,were *** experiments showed that the promoter of U32 glnA （pglnA） was likely to have two transcriptioninitiation sites:P1and P2,located 157 and 45 nucleotides （nt） upstream of the translational start codon,*** mobility shift and DNase I footprinting analyses revealed a 30 bp cis-element locatedat 45 to 75 nt downstream of P1,or 38 to 68 nt upstream of *** sequence of the cis-element displayedhigh similarity to the corresponding regions of pglnA from Streptomyces coelicolor and *** as a reporter gene,the expression levels of U32 pglnA and its deletion derivatives under differentnitrogen-source conditions were analyzed by detecting the catechol dioxygenase activities in ***54,*** J508 and *** FS10 （glnR mutant）.These in vivo studies showed that theactivation of U32 pglnA in *** required GlnR,and its binding to the U32 pglnA was furtherconfirmed by the gel mobility shift *** and heterologous expression of the U32 glnR allowed usto detect the in vitro interaction between the U32 GlnR and the corresponding pglnA *** shown by in vivo glnR inactivation and complementation indicated that GlnR is essential for theactive transcription of glnA in U32.

关键词： glnA promoter cis-element glnR Amycolatopsis mediterranei

Bacterial Type Ⅰ Glutamine Synthetase of the Rifamycin SV Producing Actinomycete,Amycolatopsis mediterranei U32,is the Only Enzyme Responsible for Glutamine Synthesis under Physiological Conditions

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Acta Biochimica et Biophysica Sinica 2006年第12期 821-830页

作者： Wen-Tao PENG~(1&) Jin WANG~1 Ting WU~2 Jian-Qiang HUANG~1 Jui-Shen CHIAO~1 Guo-Ping ZHAO~(1,3,4) 1 laboratory of molecular Microbiology,Institute of Plant Physiology and Ecology,shanghai Institutes for Biological sciences,Chinese Academy of sciences,shanghai 200032,china 2 department of Medicinal Chemistry,School of Pharmacy,fudan university,shanghai 200032,china 3 State key laboratory of Genetic engineering/department of Microbiology,School of Life science,fudan university,shanghai 2..433,china 4 laboratory of Health and Disease Genomics,Chinese National Haman Genome Center at shanghai,shanghai 201203,china

The structural gene for glutamine synthetase,glnA,from Amycolatopsis mediterranei U32 wascloned via screening a genomic library using the analog gene from Streptomyces *** clone wasfunctionally verified by complementing for glutamine requirement of an Escherichia coli glnA null mutantunder the control of a lac *** analysis showed an open reading frame encoding a protein of466 amino acid *** deduced amino acid sequence bears significant homologies to other bacterialtype Ⅰ glutamine synthetases,specifically,71% and 72% identical to the enzymes of *** and Myco-bacterium tuberculosis,*** of this glnA gene in *** U32 led to glutamineauxotrophy with no detectable glutamine synthetase activity in *** contrast,the cloned glnA+gene cancomplement for both phenotypes in *** thus suggested that in *** U32,the glnA geneencoding glutamine synthetase is uniquely responsible for in vivo glutamine synthesis under our laboratorydefined physiological conditions.

关键词： glnA glutamine synthetase Amycolatopsis mediterranei rifamycin SV

The Assembling of Charged and Uncharged Entities and Its Biological Implication

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The Assembling of Charged and Uncharged Entities and Its Bio...

THE THREADING-UNTHREADING EQUILIBRIUM IN SOLUTION OF molecular NANOTUBE AND LINEAR FLEXIBLE POLYMER CHAIN

2006年海峡两岸高分子学术研讨会

作者： Yuliang Yang The key laboratory of molecular engineering of polymers, Ministry of Education, department of macromolecular science, fudan university, Shangha, 2..433

＜正＞We aim at investigating the self-assembly of charged and uncharged entities both experimentally and theoretically in order to gain insights into some biological processes. As a first step, the particular behavior of threading and unthreading of neutral molecules such as cyclodextrins （CDs） by threading a linear polymer chain is explored theoretically and the calculation result is agreement quite well with our recent experimental observations. We have further studied the self-assembled dynamics of complexes comprised of a charged polyelectrolyte molecule and a finite cylinder with opposite charges as a chromatin model system by using Langevin dynamic simulation. The main contents are as follows.

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THE THREADING-UNTHREADING EQUILIBRIUM IN SOLUTION OF MOLECUL...