FIBERS AND POLYMERS
·
2015
·Vol. 16
·期 8
·1772-1780
·
IF 0.881
Zhou Yingsong,Yu Junrong,Wang Xuexin,Wang Yan,Zhu Jing,Hu Zuming
Melamine-formaldehyde/polyvinyl alcohol (MF/PVA) composite membranes modified by nano silica (SiO 2 ) and silane coupling agent KH570 modified SiO 2 (KH570-SiO 2 ) were prepared. The surface properties and morphology of KH570-SiO 2 were characterized using fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TGA), contact angle measurement instrument and X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and particle size analyzer. The morphology and properties of nanoparticles modified MF/PVA membranes were also studied with scanning electron microscopy (SEM), TGA, dynamic mechanical analysis (DMA) and tensile tester. The results show that KH570 is grafted on the surface of nano SiO 2 . KH570-SiO 2 has better dispersion in MF/PVA resin than that of unmodified SiO 2 . The thermal stability, mechanical and crystallizing properties of MF/PVA membrane are increased after modified with nano SiO 2 . KH570-SiO 2 makes MF more compatible with PVA resin, and further increases the mechanical properties and thermal stability of MF/PVA membrane.
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高影响因子
BMC Complementary and Alternative Medicine
·
2015
·Vol. 15
·期 1
·1-10
·
IF 2.02
Li Wei,Luo Zhenhua,Liu Xingde,Fu Lingyun,Xu Yini,Wu Lirong,Shen Xianchun
Background To investigate the ameliorated effects of an extract of Ginkgo biloba extract (GBE) on experimental cardiac remodeling in rats induced by acute cardiac infarction, and further explore the mechanism concentrated on myocardial type I collagen, transforming growth factor beta 1 (TGF-β1), matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9), and provide the experimentaldata for clinical application of GBE.Methods Rats were divided into five groups (n = 20) as following: sham operation group (group A), acute myocardial infarction model group (group B), acute myocardial infarction model + aspirin (10 mg/kg) treatment group (group C), acute myocardial infarction model + captopril (20 mg/kg) treatment group (group D) and acute myocardial infarction model + Ginkgo biloba extract (100 mg/kg) treatment group (group E). The rat acute myocardial infarction model was reproduced by ligaturing the left anterior descending artery excluding the sham operation group which did not ligation only completed the operational process. Each group was further subdivided into treatment regimens lasting 4 weeks and 8 weeks. Immunohistochemistry and real-time polymerase chain reaction (PCR) methods were used to detect the protein expression and mRNA transcriptional levels of rat myocardial TGF-β1, type I collagen, MMP-2 and MMP-9.Results Compared with group B, regardless of the length of treatment (4 or 8 weeks), the TGF-β1, MMP-2 and MMP-9 mRNA transcriptional levels, and the protein expression levels of type I collagen, MMP-2 and MMP-9 in groups D, C and E were significantly decreased (P < 0.01). Furthermore, the mRNA expression levels of TGF-β1 in groups D, C and E were significantly lower after 8 weeks compared to after 4 weeks (P < 0.01), as were the expression levels of type I collagen in groups D, C and E (P < 0.05). There was no statistically significant difference in the protein expression levels of MMP-2 and MMP-9 between groups E and C.Conclusion sGBE could inhibit experimental rat myocardial remodeling after acute myocardial infarction via reduced transcription of TGF-β1, MMP-2 and MMP-9 genes and by the decreased expression of type I collagen, MMP-2 and MMP-9 proteins in myocardial cells.
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PubMed
高影响因子
Science China-Materials
·
2015
·Vol. 58
·期 9
·693-703
·
IF 0
Liu Jian,Zhao Yuheng,Liu Jialong,Wang Shouguo,Cheng Yan,Ji Muwei,Zhou Yuanmin,Xu Meng,Hao Weichang,Zhang Jiatao
Heterovalent doping represents an effective method to control the optical and electronic properties of semiconductor nanocrystals (NCs), such as the luminescence and electronic impurities (p-, n-type doping). Considering the phase structure diversity, coordination varieties of Cu atoms in Cu 2 S NCs, and complexity of Cu doping in II-VI NCs, monodisperse Cu 2 S NCs with pure hexagonal phase were synthesized firstly. Then through cation exchange reaction between Cd ions and well-defined Cu 2 S NCs, dominant Cu(I) doped CdS NCs were produced successfully. The substitutional Cu(I) dopants with controllable concentrations were confirmed by local atom-specific fine structure from X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) spectroscopy, elemental analysis characterizations from X-ray photoelectron spectroscopy (XPS) and the electron spin resonance (ESR) measurement. The dominant and strong Cu(I) dopant fluorescence was verified by their absorption and photoluminescence (PL) spectra, and PL lifetime. Finally, the band positions and the p-type conductivities of the as-prepared Cu 2 S and Cu(I) doped CdS NCs were identified by ultraviolet photoelectron spectroscopy (UPS) measurements. The high monodispersity of NCs enables their strong film-scale self-assembly and will hasten their subsequent applications in devices.
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COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 294
·期 1
·135-143
·
IF 1.865
Guo Yanzhu,Zhang Li,Li Haiming,Han Ying,Zhou Jinghui,Wang Xiaohui
A series of α-tocopherol succinate-conjugated hydroxyethyl cellulose (HEC-TOS) polymers were synthesized in this study. The weight percentages of TOS in HEC-TOS were varied from 15 to 36 % by adjusting the weight ratios of TOS to HEC from 1:4 to 5:2. The HEC-TOS polymers exhibited typical properties of amphiphilic polymers and were able to self-assemble into spherical nanomicelle in aqueous solution as revealed by TEM. The micelle sizes and critical micelle concentrations (CMC) of HEC-TOS conjugates were correlated with their molecular structures and were in the range of 24.5–115.1 nm and 16–99 μg/ml, respectively. Paclitaxel (PTX) was encapsulated into the core of HEC-TOS micelle by sonication-dialysis method. The highest loading concentration of PTX in micelle was 315 mg/ml, which was about 50 times higher than that in water (6 mg/l). The in vitro study showed that PTX was continuously released from PTX-loaded micelle in phosphate buffered saline (PBS) medium for 108 h.
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高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 13
·2131-2138
·
IF 3.741
Xu Jingyue,Li Ying,Bie Jiaxin,Jiang Wei,Guo Jiajia,Luo Yeli,Shen Fei,Sun Chunyan
A sensitive, specific and rapid colorimetric aptasensor for the determination of the plasticizer bisphenol A (BPA) was developed. It is based on the use of gold nanoparticles (AuNPs) that are positively charged due to the modification with cysteamine which is cationic at near-neutral pH values. If aptamers are added to such AuNPs, aggregation occurs due to electrostatic interactions between the negatively-charged aptamers and the positively-charged AuNPs. This results in a color change of the AuNPs from red to blue. If a sample containing BPA is added to the anti-BPA aptamers, the anti-BPA aptamers undergo folding via an induced-fit binding mechanism. This is accompanied by a conformational change, which prevents the aptamer-induced aggregation and color change of AuNPs. The effect was exploited to design a colorimetric assay for BPA. Under optimum conditions, the absorbance ratio of A
527 / A
680 is linearly proportional to the BPA concentration in the range from 35 to 140 ng∙mL −1 , with a detection limit of 0.11 ng∙mL −1 . The method has been successfully applied to the determination of BPA in spiked tap water and gave recoveries between 91 and 106 %. Data were in full accordance with results obtained from HPLC. This assay is selective, easily performed, and in our perception represents a promising alternative to existing methods for rapid quantification of BPA.
The negatively-charged anti-BPA aptamers can absorb onto the positively-charged cysteamine-capped AuNPs (cysteamine-AuNPs) via electrostatic interactions, which can cause the aggregation of AuNPs accompanied by a red-to-blue color change. In the presence of BPA, the specific binding of BPA to the aptamers induces the conformation changes of anti-BPA aptamers, which can release the aptamers from cysteamine-AuNPs and thus prevent the aggregation and color change of cysteamine-AuNPs.
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高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2015
·Vol. 75
·期 1
·25-30
·
IF 1.532
Chen Jin,Chen Qinmiao,Ni Yi,Yamaguchi Yoshinori,Wang Tingting,Jia Zhen,Dou Xiaoming,Zhuang Songlin
Abstract
In the present work, Cu 2 ZnSnS 4 (CZTS) nanoparticles (NPs) for use in low-cost thin film solar cells were successfully synthesized using a facile open-air solution route. Copper(II) chloride dihydrate, zinc(II) acetate dihydrate, tin(II) chloride, and thiourea were used as reagents, and oleylamine was employed as solvent. The effect of varying the Zn content in the precursor solution on the structural, morphological, compositional, and optical properties of the as-synthesized CZTS NPs was investigated via X-ray diffraction, scanning electron microscopy and transmission electron microscopy, energy dispersive X-ray spectroscopy and ultraviolet–visible–infrared spectroscopy, respectively. As observed, the properties of the as-synthesized NPs improved with increasing Zn precursor contents from 0.75 to 1.5 mmol. For instance, the crystallinity of the as-synthesized NPs improved gradually and the band gap energy was tuned from 1.28 to 1.41 eV. The Zn/Sn ratio increased from 0.51 to 0.86, whereas the Cu/(Zn + Sn) ratio decreased from 0.95 to 0.7 with increasing Zn precursor contents. The results indicated that the obtained CZTS NPs, prepared with a Zn precursor content of 1.5 mmol, are a good light-absorbing layer material for application in thin film solar cells. Graphical Abstract
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高影响因子
MONATSHEFTE FUR CHEMIE
·
2014
·Vol. 145
·期 12
·1925-1931
·
IF 1.347
Tu Xingzhao,Zhou Lihong,Li Zhijie,Lei Ning,Zeng Qingle
Abstract The carbon-heteroatom bond formation is an important research field. Transition-metal-free synthesis of medicinally important heterocycles avoids products of transition metal contamination, and thus it is an environmentally friendly and cost-saving process. A transition-metal-free domino C-S/C-N formation for the synthesis of imidazobenzothiazines from 2-mercaptobenzimidazoles and 2-halobenzyl bromides is developed. The desired products were obtained in good to excellent yields. The mechanism of domino nucleophilic substitution (S N 2) and nucleophilic aromatic substitution (S N Ar) is proposed. Graphical abstract
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 49
·期 9
·3391-3399
·
IF 2.305
Jie Zhiqiang,Zhang Bing,Zhao Lianhong,Yan Xiufang,Liang Jie
A novel regenerable antimicrobial silica gel was prepared by a dehydration between silanols of silica gel and hydrolyzed 3-chloropropyltrimethoxysilane, a quaternization between grafted hydrolyzed 3-chloropropyltrimethoxysilane and (5,5-dimethylhydantoinyl-3-ylethyl)-dimethylamine (DHEDA), and a chlorination of amide groups of DHEDA. The as-prepared antimicrobial silica gel was characterized by FT-IR and X-ray photoelectron spectroscopy. Antimicrobial tests showed that the as-prepared antimicrobial silica gel was capable of about a 6-log inactivation of Staphylococcus aureus and Escherichia coli O157:H7 within 10 min of contact. Interestingly, more than 2 × 10 4 CFU/mL of Escherichia coli O157:H7 could be almost inactivated under flowing water condition. Furthermore, the as-prepared antimicrobial silica gel exhibits good regenerability and storage stability.
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高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 5
·565-572
·
IF 3.719
Ma Ming,Tu Xiaojing,Zhan Guoqing,Li Chunya,Zhang Shenghui
The ionic liquid 1-butyl -3-[3-(N-pyrrole)-propyl]imidazolium tetrafluoroborate was employed to fabricate a glassy carbon electrode (GCE) modified with a porous film of a polymerized ionic liquid. The resulting film electrode was treated with sodium dodecyl sulfonate solution to exchange the terafluoroborate anions by dodecyl sulfonate groups. This was confirmed by X-ray photoelectron spectroscopy. The morphology of the modified GCE was characterized by scanning electron microscopy and revealed a nanoporous surface. The electrochemical properties of this film electrode were studied by electrochemical impedance spectroscopy using the hexacyanoferrate(II/III) system as an electroactive probe. The response to bisphenol A was investigated by voltammetry. Compared to the unmodified GCE, the oxidation potential is positively shifted, and the oxidation peak current is strongly increased. Experimental conditions were optimized and resulted in an oxidation peak current that is linearly related to concentration of bisphenol A in the 10 nM to ~ 10 μM range. The detection limit is 8.0 nM (at S / N = 3). The electrode was successfully applied to the determination of bisphenol A in leachates of plastic drinking bottles, and its accuracy was verified by independent assays via HPLC.
A poly{1 -butyl -3 -[3 -(N -pyrrole)propyl] imidazolium dodecyl sulfonate ionic liquid} nanoprous film electrode was fabricated with potential step technique and anionic exchange. The obtained polymerized ionic liquid film electrode was demonstrated possessing enhanced effects for bisphenol A determination.
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高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2013
·Vol. 24
·期 3
·582-590
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IF 1.174
Li Xin,Bi Cai-Feng,Fan Yu-Hua,Zhang Xia,Zhang Nan,Yan Xing-Chen
A novel transition metal coordination polymer [Co 3 (C 14 H 8 NO 4 Cl) 4 (CH 3 OH) 4 ·4CH 3 OH] n with Schiff base (C 14 H 8 NO 4 Cl: 4-chloroanthranilic acid- 2,4-dihydroxybenzaldehyde) was synthesized using 4-chloroanthranilic acid, 2,4-dihydroxybenzaldehyde and cobalt(II) acetate as source, and its structure was characterized by IR spectroscopy, elemental analysis, 1 H NMR and single crystal X-ray diffraction. X-ray crystallography shows that every cobalt atom is six-coordinated. Two cobalt atoms on the two sides are respective coordinated with two nitrogen atoms from –C=N–, two carboxylic oxygen atoms and two hydroxyl oxygen atoms in different ligands, while the cobalt atom in the middle links two ligands on the side through two carboxylic oxygen atoms and coordinates with four oxygen atoms of methanol, forming a three-nuclear Co(II) complex. The complex forms a two-dimensional layer structure through O–H···O intermolecular hydrogen bonds. The interaction of the Co(II) complex with calf-thymus DNA (CT-DNA) was investigated by UV absorption spectroscopy, fluorescence emission spectroscopy, viscosity and cyclic voltammetry. All measurements revealed that the Co(II) complex binds to DNA via a intercalative mode.
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高影响因子
BIOMEDICAL MICRODEVICES
·
2013
·Vol. 16
·期 2
·237-243
·
IF 2.718
Lei Jian,Lei Chong,Wang Tao,Yang Zhen,Zhou Yong
An investigation of targeted biomolecules was accomplished by combining a micro-fluxgate-based bio-sensing system and Dynabeads. The fluxgate sensor for biomolecule detection was fabricated by Micro Electro-Mechanical system technology, including thick photoresist lithography, electroplating and chemical wet etching. The magnetic core of the sensor was made of Fe-based amorphous ribbon core and three dimension solenoid coils were used as magnetic sensitive elements. The micro-fluxgate-based bio-sensing system was characterized firstly in different concentrations of Dynabeads, and a concentration as low as 100 ng/ml was detected with an external dc magnetic field in the range of 525 μT to 875 μT. Sandwich assays are performed using antibody-antigen pair combination of biotin-streptavidin on a separated Au film substrate surface with a self-assembled layer. Detection of Alpha Fetoprotein antigens with different concentrations was performed and a minimum detectable concentration of 1 pg/ml was achieved by the bio-sensing system. It is of considerable interest due to its potential application in the biomedical field based on known specific binding of target and labels.
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PubMed
高影响因子
Food Analytical Methods
·
2013
·Vol. 7
·期 7
·1381-1386
·
IF 1.969
Ma Xiaoxing,Wang Juntao,Wu Qiuhua,Wang Chun,Wang Zhi
A new analytical method by graphene-reinforced hollow fiber liquid-phase microextraction combined with high-performance liquid chromatography fluorescence detection was developed for the determination of bisphenol A and 4- tert -butylphenol in bottled juices. Several important experimental parameters were studied to get optimal extraction conditions for the analytes. Under the optimized conditions, the method showed a good performance having a linear response in the range from 0.05 to 10.0 ng mL −1 with the correlation coefficients ( r ) of 0.9965–0.9994 and limits of detection of 0.01 ng mL −1 . The relative standard deviations were in the range from 6.4 to 7.2 % at the spiked concentration of 1.0 ng mL −1 . The method combines the high-adsorption capacity of graphene and the excellent clean-up performance of hollow fiber liquid-phase microextraction and has been successfully applied to the analysis of the analytes in bottled juice samples.
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高影响因子
危险品化学品经营许可证（带存储）