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Bioreducible unimolecular micelles based on amphiphilic multiarm hyperbranched copolymers for triggered drug release

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Science China Chemistry 2010年第12期53卷 2497-2508页

作者： PANG Yan 1,LIU JinYao 1,SU Yue 1,ZHU BangShang 2,HUANG Wei 1,ZHOU YongFeng 1,ZHU XinYuan 1,2 & YAN DeYue 1 1 School of Chemistry and Chemical Engineering,State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China 2 Instrumental Analysis Center,Shanghai Jiao Tong University,Shanghai 200240,China School of Chemistry and Chemical Engineering State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai China Instrumental Analysis Center Shanghai Jiao Tong University Shanghai China

A novel type of bioreducible amphiphilic multiarm hyperbranched copolymer (H40-star-PLA-SS-PEG) based on Boltorn H40 core,poly(L-lactide) (PLA) inner-shell,and poly(ethylene glycol) (PEG) outer-shell with disulfide-linkages between the hydrophobic and hydrophilic moieties was developed as unimolecular micelles for controlled drug release triggered by *** obtained H40-star-PLA-SS-PEG was characterized in detail by nuclear magnetic resonance (NMR),Fourier transform infrared (FTIR),gel permeation chromatography (GPC),differential scanning calorimeter (DSC),and thermal gravimetric analysis (TGA).Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analyses suggested that H40-star-PLA-SS-PEG formed stable unimolecular micelles in aqueous solution with an average diameter of 19 ***,these micelles aggregated into large particles rapidly in response to 10 mM dithiothreitol (DTT),most likely due to shedding of the hydrophilic PEG outer-shell through reductive cleavage of the disulfide *** a hydrophobic anticancer model drug,doxorubicin (DOX) was encapsulated into these reductive unimolecular *** vitro release studies revealed that under the reduction-stimulus,the detachment of PEG outer-shell in DOX-loaded micelles resulted in a rapid drug *** cytometry and confocal laser scanning microscopy (CLSM) measurements indicated that these DOX-loaded micelles were easily internalized by living *** tetrazolium (MTT) assay demonstrated a markedly enhanced drug efficacy of DOX-loaded H40-star-PLA-SS-PEG micelles as compared to free *** of these results show that these bioreducible unimolecular micelles are promising carriers for the triggered intracellular delivery of hydrophobic anticancer drugs.

关键词： hyperbranched polymer unimolecular micelle drug delivery

Theoretical calculations of the unimolecular canonical rate constants

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Science China Chemistry 1996年第6期39卷 593-597页

作者：李宗和冯文林王艳张绍文刘若庄 Department of Chemistry Beijing Normal University Beijing 100875 China

Microcanonical rate constants k(E) and canonical rate constants k(T) for unimolecular reactions have been obtained through the calculations of cumulative reaction probabilities N(E) with the unsymmetrical Eckart potential tunneling correction. By way of example, the reactions HCN→CNH (I) and FNC→NCF (II) have been employed. For reaction (I), the calculated rate constants are in agreement with the experimental data; for reaction (II), the results are in accordance with the rate constants kCVT/MEPSAG(T) calculated by the common program POLYRATE.

关键词： unimolecular reaction rate constant theoretical calculation.

Ab Initio and RRKM Study of the unimolecular Decomposition of Five-membered Ring Heterocyclic (X:O,S,N-H)

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Chinese Journal of Structural Chemistry 2012年第8期31卷 1121-1128页

作者： Abolfazl Shiroudi Ehsan Zahedi Chemistry Department Shahrood BranchIslamic Azad University

Quantum mechanical and Rice-Ramsperger-Kassel-Marcus （RRKM） calculations are carried out to study the thermal unimolecular decomposition of 2,5-dihydrofuran （1）,2,5dihydrothiophene （2）,and 3-pyrroline （3） at the MPW1PW91/6-31＋＋G level of theory,and the results are in good agreement with the experimental *** predicted high pressure limit rate constants （k（T）） in various states of activation energy and pre-exponential （S1：（A（calc.）,E a（calc.））,S2：（A （calc.）,E a（exp.））,and S3：（A （exp.）,E a（calc.））） for the thermal decomposition processes 1-3 were ***,the fall-off pressures （P1/2） for compounds 1-3 in the states 1-3 are found to be （1.24×10-2,1.09×10-3,and 4.19×10-2mmHg）,（1.24×10-2,1.63×10-3,and 2.79×10-2mmHg）,and （1.24×10-2,1.63×10-3,and 4.19×10-2 mmHg）,*** the fall-off pressure of thermal decomposition process of compounds 1-3 is in the following order：P1/2（3）〉 P1/2（1）〉 P1/2 （2）,the decomposition rates are as below：rate（3）〈rate（1）〈rate（2）.

关键词： unimolecular calculate method molecular modeling decomposition fall-off pressure RRKM

A three-dimensional ratiometric sensing strategy on unimolecular fluorescence—thermally activated delayed fluorescence dual emission

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Science Foundation in China 2019年第1期27卷 28-28页

With the support by the National Natural Science Foundation of China and partially by the National Key Research and Development Program of China,the research team led by *** LiangLiang(朱亮亮)at the State Key Laboratory of Molecular Engineering of Polymers,Department of Macromolecular Science,Fudan University,cooperated with the research team led by Prof.

关键词： A three-dimensional ratiometric sensing strategy unimolecular

Theoretical Study and NBO Analysis of the Decomposition Kinetics of Oxetane, 2-Methyloxetane and 2,2-Dimethyloxetane

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Chinese Journal of Structural Chemistry 2011年第5期30卷 697-705页

作者： Arezoo Tahan Abolfazl Shiroudi Semnan Branch Islamic Azad University Chemistry Department Shahrood BranchIslamic Azad University

A theoretical study of the thermal decomposition kinetics of oxetane （1）, 2-methyloxetane （2）, and 2,2-dimethyloxetane （3） has been carried out at the B3LYP/6-311＋G＊＊, B3PW91/6-311＋G＊＊, and MPW1PW91/6-311＋G＊＊ levels of theory. The MPW1PW91/6-311＋G＊＊ method was found to give a reasonable good agreement with the experimental kinetics and thermodynamic parameters. The decomposition reaction of compounds 1～3 yields formaldehyde and the corresponding substituted olefin. Based on the optimized ground state geometries using MPW1PW91/6-311＋G＊＊ method, the natural bond orbital （NBO） analysis of donor-acceptor （bond-antibond） interactions revealed that the stabilization energies associated with the electronic delocalization from σC3-C4 bonding to σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. The σC3-C4→σO1-C2 resonance energies for compounds 1～3 are 2.63, 2.59 and 2.45 kcal mol-1, respectively. Further, the results showed that the energy gaps between σC3-C4 bonding and σ＊O1-C2 antibonding orbitals decrease from compounds 1 to 3. Also, the decomposition process in these compounds are controlled by σ→σ＊ resonance energies. Moreover, the obtained order of energy barriers could be explained by the number of electron-releasing methyl groups substituted to the Csp3 atom （which is attached to oxygen atom）. NBO analysis shows that the occupancies of σCsp3-O bonds decrease for compounds 1～3 as 3〈2〈1, and those of σCsp3-O bonds increase in the opposite order （3 〉 2 〉 1）. This fact illustrates a comparatively easier thermal decomposition of the sCsp3-O bond in compound 3 compared to compound 2, and in compound 2 compared to compound 1. NBO results indicate that these reactions are occurring through a concerted and asynchronous four-membered cyclic transition state type of mechanism.

关键词： unimolecular ab initio molecular modeling decomposition DFT NBO