CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2013
·Vol. 29
·期 2
·245-248
·
IF 0.735
Liang Di,Yang Xiao-hong,Sun Wei,Wang Wen-na,Yang Jin-zhu,Liu Yin-yan,Wang Guang-shu
The prodrug, naproxen-eugenol ester, was synthesized by acyl chloride method with naproxen and eugenol as the raw materials. The structure was identified by proton nuclear magnetic resonance( 1 H NMR), mass spectrometry(MS), infrared spectrometry(IR) and X-ray diffraction. The compound was crystallized in the orthorhombic system, space group P 2 1 2 1 2 1 with unit cell dimensions a= 0.60563(12) nm, b =1.0234(2) nm, c =3.2654(7) nm, α =90°, β =90°, γ =90°, V =2.0240(7) nm 3 , Z =4. Calculated density 1.235 Mg/m 3 ; absorption coefficient: 0.083 mm −1 ; F (000)=800; final R
1 =0.0564. The analgesic activity and anti-inflammatory were similar to those of naproxen, and the results of ulcerogenic activity indicate that the prodrug can significantly decrease the irritation after oral administration.
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高影响因子
MICROCHIMICA ACTA
·
2013
·Vol. 180
·期 7
·627-633
·
IF 3.434
Zhang Li,Yuan Sheng-mei,Yang Li-ming,Fang Zhen,Zhao Guang-chao
A glassy carbon electrode was modified with β-manganese dioxide (β-MnO 2 ), and glucose oxidase (GOx) was immobilized on its surface. The β-MnO 2 nanowires were prepared by a hydrothermal method and characterized by scanning electron microscopy and powder X-ray diffraction. They were then dispersed in Nafion solution and cast on the glassy carbon electrode (GCE) to form an electrode modified with β-MnO 2 nanowires that exhibits improved sensitivity toward hydrogen peroxide. If GOx is immobilized in the surface, the β-MnO 2 acts as a mediator, and Nafion as a polymer backbone. The fabrication process was characterized by electrochemical impedance spectroscopy, and the sensor and its materials were characterized by cyclic voltammetry and amperometry. The biosensor enables amperometric detection of glucose with a sensitivity of 38.2 μA · mM −1 · cm −2 , and a response time of < 5 s. This study also demonstrates the feasibility of realizing inexpensive, reliable, and high-performance biosensors using MnO 2 nanowires.
The sensitive determination of glucose was realized at a β-MnO 2 NWs modified glassy carbon electrode by amperometry. The relatively fast, reproducible and low-cost manufacturing procedure suggests that it can offer an excellent platform for glucose oxidase-biosensing applications.
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高影响因子
IRANIAN POLYMER JOURNAL
·
2013
·Vol. 22
·期 5
·325-334
·
IF 1.053
Zheng Yin,Zou Bo,Yuan Liangjie
Two novel epoxy resins; namely, R1 and R2 were synthesized and characterized. These two resins were isomers and both contained naphthalene units and two symmetric flexible aliphatic ester chains terminated by epoxy groups. To investigate the influence of different structural isomers on the performance of these epoxy resins, they were both cured with various curing agents which results in the choosing of 4,4′-diaminodiphenylmethane (DDM) as the optimized curing agent. The curing technical temperature was obtained from extrapolated plots of T– β curve at different heating rates. The kinetic parameters, the activation energy ( E
a ) and the reaction order ( n ) were deduced by Kissnger’s isoconversional method and Crane equation. The moisture absorption and mechanical and thermal properties of the cured epoxy resins were investigated. Experimental results indicated that the R1/DDM and R2/DDM epoxy resins displayed improved mechanical performance without significant decrease in their important inherent properties, e.g., temperature of glass transition ( T
g ), moisture absorption and thermal properties when compared with the corresponding commercial biphenyl-type epoxy resins. The average inter-segment distances in R1/DDM and R2/DDM systems were 4.46 and 4.88 Å, respectively, which were measured by wide-angle X-ray diffraction. The result showed R1/DDM (1,5-di-substituted) was strongly hindered in comparison with R2/DDM (2,7-di-substituted) and E
a and T
g values of the R1/DDM were slightly higher than those of R2/DDM. Furthermore, mechanical properties and moisture absorption of the R1/DDM were lower than those of R2/DDM. Nevertheless, the position of the substituent only weakly affected the thermal properties and the reaction order ( n ).
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高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2013
·Vol. 113
·期 3
·683-692
·
IF 1.545
Luo Chenghao,Lu Weili,Li Yu,Feng Yiyu,Feng Wei,Zhao Yunhui,Yuan Xiaoyan
Carbon nanofibers (CNFs) embedded with various amounts of Ni and NiO nanoparticles (C/Ni–NiO) were prepared by electrospinning of polyacrylonitrile (PAN), followed by heat treatment. The structure and composition of the obtained C/Ni–NiO composite nanofibers were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results suggested that the morphology, nanofiber diameter, and the content of the Ni–NiO nanoparticles in the CNFs were controlled by different amounts of nickel acetate added into the PAN. The electrochemical measurements of a charge/discharge experiment and a cyclic voltammetry test indicated that the content and the size of Ni–NiO nanoparticles embedded in the CNFs had a great influence on the electrochemical performance of lithium-ion batteries. CNFs embedded with a certain content of Ni–NiO nanoparticles as binder-free anodes for rechargeable lithium-ion batteries exhibited improved electrochemical performance, including high reversible capacities, good capacity retention, and stable cycling performance. This is mainly ascribed to the formation of a well-distributed Ni–NiO nanoparticle structure and the buffering role of the carbon nanofiber matrix, together with the high theoretical capacity of NiO and the increase in electrode connectivity caused by the formation of electrochemically inactive Ni nanoparticles.
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高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2013
·Vol. 31
·期 6
·894-900
·
IF 1.27
Zhang Min-min,Liu Si-wei,Zhang Yi,Chen Liang-hui,Chi Zhen-guo,Xu Jia-rui
A new macromolecular surface modifier, a copolymer of lauryl methacrylate (LMA) and poly(ethylene glycol) methyl methacrylate (PEGMA), was synthesized through free radical polymerization. The copolymer was characterized by nuclear magnetic resonance spectrum ( 1 H-NMR) and thermogravimetric analysis (TGA). The copolymer was used to blend with polyethylene. The binary blends have been characterized by attenuated total reflection/Fourier transform infrared (ATRFTIR), contact-angle measurements (CDA) and scanning electron microscopy (SEM). The results indicated that poly(ethylene glycol) methyl methacrylate- co -lauryl methacrylate (PEGMA- co -LMA) could diffuse preferably onto the surface of the polyethylene (PE) film, and thus can be used as an efficient surface modifier for PE.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2013
·Vol. 48
·期 17
·5750-5755
·
IF 2.163
Song Kai,Zhao Xiaoying,Xu Yueming,Liu Hewen
In this paper, we report on an effective surface modification method for the functionalization of graphene oxide (GO) via photo-initiated radical polymerization. Two cases are investigated, i.e., photoinitiators are chemically attached on GO or are just mixed with GO. The monomer used for surface graft is water-soluble 2-(dimethylamino) ethyl methacrylate (DMAEMA). Analysis based on Fourier transform infrared spectra, Raman spectra, X-ray photoelectron spectroscopy, thermogravimetric analysis, and element analysis demonstrates that PDMAEMA chains are successfully grafted onto GO surface in both cases. In addition, we study the effects of UV irradiation energy and the concentration of initiators on the polymerization. Both UV irradiation energy and the concentration of initiators do not have significant effects on the grafting degree; however, the concentrations of the initiators have impact on the length of the polymer chains grafted onto GO in the case of mixed photoinitiators with GO. The chain length of polymer is shorter with the higher photoinitiator concentration.
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PHARMACEUTICAL RESEARCH
·
2013
·Vol. 30
·期 10
·2538-2548
·
IF 4.742
Gao Xihui,Qian Jun,Zheng Shuyan,Xiong Ying,Man Jiahao,Cao Binxin,Wang Lu,Ju Shenghong,Li Cong
Purpose To investigate the multivalent effect for up-regulating the intracerebral delivery of nanoparticles via receptor-mediated transcytosis. Methods Nanoparticles labeled with near-infrared (NIR) fluorophore and different numbers of angiopep-2 peptides that specifically target low-density lipoprotein receptor-related protein (LRP) on the brain capillary endothelial cells were developed. Bio-distribution studies quantified the intracerebral uptakes of these nanoparticles at 2 and 24 h after intravenous injection. In vivo NIR fluorescence imaging, ex vivo autoradiographic imaging and 3D reconstructed NIR fluorescence imaging revealed the nanoparticle distribution pattern in brain. Fluorescence microscopic imaging identified the nanoparticle locations at the cellular level. Results The multimetirc association between the angiopep-2 peptides labeled on the nanoparticle and the LRP receptors on the brain capillary endothelial cells significantly increased the intracerebral uptake of the nanoparticles. Nanoparticle Den-Angio4 labeled four angiopep-2 peptides achieved the highest BBB traverse efficacy. After penetrating the BBB, Den-Angio4 distributed heterogeneously and mainly located at hippocampus, striatum and cerebellum in the brains. Conclusions The multivalent effect significantly enhances the BBB permeability of nanoparticles. Den-Angio4 as a nanoparticle prototype provides a two order targeted strategy for diagnosis or treatment of central nerver system diseases by first traversing the BBB via receptor-mediated endocytosis and secondly targeting the leisions with high receptor expression level.
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PubMed
高影响因子
CELLULOSE
·
2013
·Vol. 20
·期 2
·849-860
·
IF 3.476
Duan Chunting,Zhao Ning,Yu Xiaolan,Zhang Xiaoyan,Xu Jian
Kapok fiber, a natural hollow fiber with thin shell and large cavity, has rarely been used as adsorbent for heavy metal ions. In this paper, kapok fibers were modified with diethylenetriamine pentaacetic acid (DTPA) after hydrophilicity treatment. The adsorption behavior of the resultant kapok-DTPA influenced by pH, adsorption time and initial concentration of metal ion was investigated. The results demonstrate that adsorption equilibrium was reached within 2 min for Pb 2+ and Cd 2+ . Adsorption kinetics showed that the adsorption rate was well fitted by pseudo-second-order rate model. The adsorption isotherms were studied, and the best fit was obtained in the Langmuir model. The maximum adsorption capacities of kapok-DTPA were 310.6 mg g −1 for Pb 2+ , 163.7 mg g −1 for Cd 2+ , 101.0 mg g −1 for Cu 2+ , respectively. After eight desorption and re-adsorption loops, the lost adsorption capacities for Pb 2+ and Cu 2+ were less than 10 %. Because of the large specific area derived from the hollow fiber structure, kapok-DTPA exhibited much better adsorption capacity compared with many other reported adsorbents based on natural materials.
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MACROMOLECULAR RESEARCH
·
2012
·Vol. 21
·期 6
·681-686
·
IF 1.153
Xu Yewei,Tang Jie,Chang Guanjun,Zhu Fanghua,Luo Xuan,Zhang Lin
Poly( N -arylenebenzimidazole ketone ketone)s (PNABIKKs) consisting of m - and p -phenylene linkages have been synthesized by nucleophilic aromatic substitution from bis(benzimidazolyl) derivatives containing sulfonyl, carbonyl, and ether groups with activated aromatic difluorides in sulfolane at 210 °C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier tramsfom infrared (FTIR), proton nuclear magnetic resonance ( 1 H NMR) spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements demonstrated that polymers had high glass transition temperatures ( T
g
>220 °C) and good thermal stability with high decomposition temperatures ( T
D
>480 °C). These novel polymers also showed good solubility.
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JOURNAL OF POLYMER RESEARCH
·
2012
·Vol. 19
·期 12
·1-8
·
IF 1.733
Ma Chi,Wang Bing,Xiong Cheng-Dong,Chen Dong-Liang,Xiong Zuo-Chun
Control of dimensional stability is crucial for using electrospun membranes in biomedical and tissue engineering applications. In this study, the contraction of electrospun membranes of poly( l -lactide-co-glycolide) (PLLGA) after stretch was investigated. Then, by adding PLLGA-b-polyethylene glycol (PLLGA-PEG), the contraction of the membranes was controlled. In addition, the mechanical properties of the membranes were investigated. On the basis of the strain–stress behavior of the membranes, an elongation of 50 % was used to investigate the orientation degrees of the membrane fibers. On the basis of the morphology of the stretched membranes, the contraction was found to depend on the orientation degree of fibers after stretch. A linear relationship between the contraction and degree of orientation after stretch was confirmed. Two-dimensional fast Fourier transform (2D FFT) analysis of the scanning electron microscopy (SEM) images of the membranes was used to quantify the orientation degree. It was surmised that the different orientation degrees were responsible for the different morphologies and thermal behaviors of the membranes.
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高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2012
·Vol. 18
·期 5
·315-319
·
IF 0
Feng Yakai,Chen Chengbin,Zhang Li,Tian Hong,Yuan Wenjie
A series of novel copolymers were successfully synthesized by ring-opening polymerization (ROP) of 3(S)-methyl-morpholine-2,5-dione (MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) using stannous octoate as catalyst. The copolymers were characterized by means of 1H-NMR and FT-IR spectroscopy. Gel permeation chromatography (GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry (DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline.
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WOOD SCIENCE AND TECHNOLOGY
·
2012
·Vol. 47
·期 3
·601-613
·
IF 1.727
Si Hongyan,Li Bin,Wang Ting,Lin Li,Xu Zuwei
Poplar wood flour, a low-cost and abundantly available material, was modified by grafting β -cyclodextrin ( β -CD) in the presence of citric acid or 1,2,3,4-Butanetetracarboxylic acid, aiming to expand the application of wood flour. The products were characterized by Fourier transform infrared spectroscopy and the technique of phenolphthalein probe. The grafting conditions of β -CD onto wood flour including curing temperature, β -CD concentration in impregnation solution and catalyst were also evaluated by the technique of phenolphthalein probe. Besides, eugenol (EG), an antibacterial fragrant guest molecule, was loaded on the modified wood flour by lyophilization, and its release characteristics were investigated by Thermo-gravimetric. The results revealed that the modified wood flour material had a thermo-protective effect on the volatilization of EG and the encapsulated EG content was reached to 1.31 %, which could demonstrate a potential application in the finishing and packing areas.
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