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Function Projective Lag Synchronization of Chaotic Systems with Certain Parameters via Adaptive-impulsive Control

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International Journal of Automation and computing 2019年第2期16卷 238-247页

作者： Xiu-Li Chai zhi-hua gan Institute of Image Processing and Pattern Recognition Henan University Institute of Intelligent Network System School of SoftwareHenan University

A new method is presented to study the function projective lag synchronization(FPLS) of chaotic systems via adaptive-impulsive control. To achieve synchronization, suitable nonlinear adaptive-impulsive controllers are designed. Based on the Lyapunov stability theory and the impulsive control technology, some effective sufficient conditions are derived to ensure the drive system and the response system can be rapidly lag synchronized up to the given scaling function matrix. Numerical simulations are presented to verify the effectiveness and the feasibility of the analytical results.

关键词： Function projective lag synchronization (FPLS) adaptive-impulsive chaotic systems numerical simulation Lyapunov stability theory

EFFECT OF SURFACE CHARGE OF POLYMERIC MICELLES ON IN VITRO CELLULAR UPTAKE

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Chinese Journal of Polymer Science 2013年第9期31卷 1299-1309页

作者： Dan-hua Zhou Jie Zhang Guan Zhang zhi-hua gan CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences Novelty Research Station for SCI-TECH Beijing University of Chemical Technology Department of Urology China-Japan Friendship Hospital State Key Laboratory of Organic-inorganic Composites Beijing Laboratory of Biomedical Materials College of Life Science and Technology Beijing University of Chemical Technology

This work focuses on the interaction between polymeric micelles with different charged surfaces and cancer cells in order to study the influence of surface charge on the in vitro cellular uptake efficiency. The amphiphilic diblock copolymers poly（e-caprolaetone）-b-poly（ethylene oxide）（PCL-b-PEO） with different functional groups at the end of hydrophilic block were synthesized. The functional groups endue the micelles with different charges on the surfaces. The cellular uptake of micelles to T-24 cells （human bladder tumor cells）, HepG2 cells （human liver hepatocellular carcinoma cell line） and Hela cells （human epithelial cervical cancer cells） was studied by means of flow cytometer and confbcal laser scanning microscopy. The results indicate that the surface charges showed great influence on zeta potential of micelles at different pH values. The in vitro cellular uptake efficiency of micelles with different charged surfaces demonstrated different cellular uptake patterns to three kinds of cancer cells.

关键词： Polymeric micelles Surface charge pH value Cellular uptake efficiency.

Folic Acid Modified Polymeric Micelles for Intravesical Instilled Chemotherapy

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Chinese Journal of Polymer Science 2018年第4期36卷 479-487页

作者： Dan-hua Zhou Guan Zhang Qing-Song Yu zhi-hua gan National University of Singapore Environmental Research Institute(NERI) National University of SingaporeSingapore 117576Singapore Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic-inorganic Composite MaterialsCollege of Life Science and TechnologyBeijing University of Chemical TechnologyBeijing 100029China Department of Urology China-Japan Friendship HospitalBeijing 100029China

In this study, a targeting micellar drug delivery system was developed for intravesical instilled chemotherapy of bladder cancer. The amphiphilic diblock copolymer poly（？-caprolactone）-block-poly（ethylene glycol）（PCL-b-PEO） with functional amino group（NH2） at the end of PEO block was synthesized. Then the copolymer was conjugated with folic acid（FA） and fluorescein isothiocyannate（FITC） via the PEO-NH2 terminus, and then assembled into micelles with the target moiety and fluorescence labeling. In addition, drug loaded micelles were also fabricated with anticancer drug doxorubicin（DOX） encapsulated in the hydrophobic core. The micelles were characterized in terms of size, drug loaded efficiency and critical micellization concentration（CMC） by means of DLS, UV and fluorescence spectra. In vitro cellular uptake and cytotoxicity studies showed that FA modified PCL-b-PEO-FA micelles have a greater targeting efficiency to human bladder cancer cell（T-24 cell） compared to PCL-b-PEO-NH2 micelles due to the conjugation of FA on the surface, while no targeting effect to normal tissue originated human embryonic kidney 293（HEK-293） cells was observed, enabling the micelles a promising drug carrier for intravesical instilled chemotherapy of bladder cancer.

关键词： Targeted drug delivery Superficial bladder cancer Intravesical instilled chemotherapy Folic acid Micelles

Influence of compression-expansion effect on oscillating-flow heat transfer in a finned heat exchanger

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第6期14卷 427-434页

作者： Ke TANG Juan YU Tao JIN zhi-hua gan Institute of Refrigeration and Cryogenics Zhejiang University

Compression and expansion of a working gas due to the pressure oscillation of an oscillating flow can lead to a temperature variation of the working gas, which will affect the heat transfer in the oscillating flow. This study focuses on the impact of the compression-expansion effect, indicated by the pressure ratio, on the heat transfer in a finned heat exchanger under practical operating conditions of the ambient-temperature heat exchangers in Stirling-type pulse tube refrigerators. The experimental results summarized as the Nusselt number are presented for analysis. An increase in the pressure ratio can result in a marked rise in the Nusselt number, which indicates that the compression-expansion effect should be considered in characterizing the heat transfer of the oscillating flow, especially in the cases with a higher Valensi number and a lower maximum Reynolds number.

关键词： Heat transfer Heat exchanger Oscillating flow Pressure ratio Pulse tube refrigerator

Preparation of Porous Polylactide Microspheres and Their Application in Tissue Engineering

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Chinese Journal of Polymer Science 2018年第6期36卷 712-719页

作者： Xu-Dong Shi Pei-Jian Sun zhi-hua gan Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China The GAS Key Laboratory of Engineering Plastics Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China State Key Laboratory of Organic-inorganic Composites College of Life Science and TechnologyBeijing University of Chemical TechnologyBeijing 100029China

In this study, porous polylactide（PLA） microspheres with different structures were prepared through the multiple emulsion solvent evaporation method. By changing organic solvents（ethyl acetate and chloroform） and adding effervescent salt NH4 HCO3 in the inner water phase, microspheres with porous capsular, matrix, microcapsular and multivesicular structures were prepared. The protein encapsulation and release, and the cell growth behavior of porous microspheres were further explored. Under the same inner water phase, microspheres prepared with chloroform had higher protein encapsulation efficiency and less protein release rate as compared with those prepared with ethyl acetate. Cell experiments showed that the relatively rough surface of microspheres prepared with chloroform was more favorable for the cell growth in comparison with the smooth surface of microspheres prepared with ethyl acetate. This study shows a simple and effective method to control the protein release and cell growth behaviors of polymer microspheres by tuning their porous structure.

关键词： Polylactide Porous microspheres Drug release Cell Tissue engineering

Computational fluid dynamic simulation of an inter-phasing pulse tube cooler

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 93-98页

作者： Xiao-bin ZHANG zhi-hua gan Li-min QIU hua-xiang LIU Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China College of Science Guangdong Ocean University Zhanjiang 524088 China

An inter-phasing pulse tube cooler (IPPTC) consists of two pulse tube units, which are connected to each other at hot ends of the pulse tubes through a needle valve. This paper presents the computational fluid dynamic (CFD) results of an IPPTC using a 2D axis-symmetrical model. General results such as the phase difference between pressure and velocity at cold end and hot end, the temperature profiles along the wall, the available lowest temperature as well as its oscillations and the coefficient of performance (COP) for IPPTC are presented. The formation of DC flow and its effects on the performance of the cooler are investigated and analyzed in detail. Turbulence, which is partially responsible for the poor overall performance of a single orifice pulse tube cooler (OPTC), is found to be much reduced in IPPTC and its performance is improved significantly compared with the single OPTC.

关键词：制冷机液体动力学内部定向脉冲管

Biodegradable Microspheres with Poly(N-isopropylacrylamide) Enriched Surface: Thermo-responsibility, Biodegradation and Drug Release

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Chinese Journal of Polymer Science 2015年第11期33卷 1598-1605页

作者： Yin Yuan 孙培健 Xu-dong Shi zhi-hua gan 王佛松 CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences the Key Laboratory of Tobacco Chemistry Zhengzhou Tobacco Research Institute China National Tobacco Corporation State Key Laboratory of Organic-inorganic Composites Beijing Laboratory of Biomedical MaterialsCollege of Life Sciences and Technology

Microspheres with thermo-responsible surface were fabricated by PCL-b-PEO-b-PNIPAM triblock copolymers. Thermo-responsible morphological changes of PCL-b-PEO-b-PNIPAM microspheres immersed in aqueous solution at temperatures above the LCST（e.g. 37 ℃） were observed from porous surface structure to compact surface layer. Enzymatic degradation and in vitro drug release results showed that the thermo-responsible surface layer greatly influenced the degradation of microspheres as well as the drug release behavior from microspheres. With the copolymerization of PNIPAM block into PCL-b-PEO copolymers, the drug release could be well regulated by changing temperatures and microspheres composition, which revealed the great potentials of microspheres with thermo-responsible surface for controlled drug release.

关键词： Microspheres Poly（N-isopropylacrylamide） Thermo-sensitive Biodegradation

Enhanced Crystallization Rate of Poly(L-lactide)/Hydroxyapatite-graftpoly(D-lactide) Composite with Different Processing Temperatures

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Chinese Journal of Polymer Science 2020年第6期38卷 599-610页

作者： Min Wang Lei-Chu You Yu-Qi Guo Ni Jiang zhi-hua gan Zhen-Bo Ning State Key Laboratory of Organic-Inorganic Composites Beijing Laboratory of Biomedical MaterialsCollege of Life Science and TechnologyBeijing University of Chemical TechnologyBeijing 100029China

Hydroxyapatite-graft-poly(D-lactide)(HA-g-PDLA)was synthesized by ring-opening polymerization with HA as initiator and stannous octanoate(Sn(Oct)2)as catalyst.Thermogravimetric analysis(TGA)and Fourier transform infrared spectroscopy(FUR)results indicate that PDLA chains are successfully grafted onto HA particles by covalent bond.Under two different processing temperatures(190 and 230℃),the effect of the grafted PDLA chains on the crystallization behavior of poly(L-lactide)/HA-g-PDLA(PLLA/HA-g-PDLA)composite was investigated in the current study,comparing to neat PLLA and its four composites(PLLA/HA,PLLA/HA-g-PLLA,PLLA/PDLA,and PLLA/HA/PDLA).The crystallization rate of PLLA/HA-g-PDLA composite is highly enhanced comparing to PLLA,PLLA/HA and PLLA/HA-g-PLLA composites in which there are no stereocomplex(SC)crystallites.In addition,when the processing temperature rises from 190℃ to 230℃,the acceleration of PLLA crystallization in PLLA/HA-g-PDLA composite is not influenced so much as other composites containing SC crystallites,such as PLLA/HA/PDLA or PLLA/PDLA.The differential scanning calorimetry(DSC)results demonstrate that even without SC crystallites,the crystallization of PLLA can still be accelerated a lot in this composite.This may be related to the interaction between the grafted PDLA chains and the amorphous PLLA chains in PLLA/HA-g-PDLA composite.The isothermal crystallization kinetics studies indicate that the nature of nucleation and crystal growth of PLLA/HAg-PDLA composite are more likely 3D crystalline growth with heterogeneous nucleation mode,which are different from PLLA or other composites.This investigation could shed new light on the application of PLLA/HA composites.

关键词： HA particles Stereocomplexation Composite Crystallization

Comb-like Poly(N-(2-hydroxypropyl) methacrylamide) Doxorubicin Conjugates: The Influence of Polymer Architecture and Composition on the Biological Properties

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Chinese Journal of Polymer Science 2018年第11期36卷 1225-1238页

作者： Hao Tang Jin Tang Yi Shen Wen-Xuan Guo Min Zhou Rui-hua Wang Ni Jiang zhi-hua gan Qing-Song Yu The State Key Laboratory of Organic-inorganic Composites Beijing Laboratory of Biomedical Materials Beijing University of Chemical Technology College of Life Science and Technology Beijing University of Chemical Technology Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology

The synthesis and structure-property correlation of poly（N-（2-hydroxypropyl） methacrylamide）（PHPMA） conjugates with various architectures including random, block, branched or star-like structures and compositions have been thoroughly explored. However, related synthesis and structure-property data are still lacking for comb-like PHPMA. In this work, we report the synthesis of comb-like PHPMA copolymer-doxorubicin （DOX） conjugates with different backbone/side-chain lengths and location of drug moieties. Well-defined comb-like PHPMA-DOX conjugates are obtained via the combination of controlled radical polymerization and fractional precipitation techniques. The influences of structural factors on the biological properties such as cellular uptake, blood circulation and tumor accumulation have been investigated. Long blood circulation and efficient tumor accumulation can be achieved by proper control of the comb number, length and location of drug moieties. These facile comb-like structures possess great potentials in future theranostics for brachytherapy or surgical navigation.

关键词： Poly（N-（2-hydroxypropyl） methacrylamide） Comb-like copolymer Anticancer drug delivery Synthesis Structure-property correlation