JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 2
·1395-1403
·
IF 2.599
Yi Mengji,Liu Yuefeng,Gao Huiping,Huang Zhangyu,Liang Jiwei,Mao Yanli
In this manuscript, Ni 2+ ions-doped NaYF 4 :Yb 3+ /Er 3+ nanoparticles have been synthesized via a modified hydrothermal method. The upconversion luminescence intensities of the green (G) and red (R) emission of NaYF 4 :Yb 3+ /Er 3+ co-doped with 20 mol% Ni 2+ ions are the strongest which increase 32.84 and 20.99 times than that without doping Ni 2+ , respectively. In addition, the R/G ratio decreases with the concentration of Ni 2+ increasing from 0 to 40 mol%. The underlying reason for luminescence enhanced and the R/G ratio decreased by Ni 2+ doping is explored by a series of controlled experiments, and the mechanism based on the crystal field asymmetry, different substitution by Ni 2+ , the energy transition of Er 3+ is studied in detail. The study indicates that the misshapen crystal field plays an important role in enhancement fluorescence emission, and several factors affect the R/G ratio including the crystal field, the substitution site and the energy transition. Our result may play a certain function for study and design of high-performance upconversion materials.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2017
·Vol. 29
·期 3
·2525-2536
·
IF 2.019
Huang Feng,Sui Yanwei,Wei Fuxiang,Qi Jiqiu,Meng Qingkun,He Yezeng
NiS x−n grown on the carbon cloth (NiS x−n //CC) were successfully prepared via a facile one-step hydrothermal technique by controlling initial S 2− /Ni 2+ molar ratio n . Serving as a supercapacitor electrode, the specific capacitance of Ni 3 S 4 //CC ( n = 3.0) has been measured to be 1340 F/g at a discharge density of 1 A/g. Also, the Ni 3 S 4 //CC displays an excellent long-time cycling stability (94.5%). Furthermore, the flexible all-solid-state supercapacitor device fabricated based on the Ni 3 S 4 //CC exhibits good supercapacitive performance with maximum power density of 6750 W/kg and superior cycling stability after 5000 continuous cycles (retention rate of cycling around 84.7%). These results indicate that the Ni 3 S 4 //CC is a promising and suitable electrode material for high-performance flexible all-solid-state supercapacitors.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-13
·
IF 4.259
Hu Dongfang,Cao Shengliang,Zhang Guihua,Xiao Yihong,Liu Sidang,Shang Yingli
Florfenicol (FLO) is one of the most popular antibiotics used in veterinary clinic and aquaculture. FLO can inhibit both bacterial and mitochondrial protein synthesis. However, the effects of FLO on mitochondrial function and cellular homeostasis remain unclear. Here we show that FLO inhibits expression of mitochondrial DNA-encoded proteins, decreases mitochondrial membrane potential, and promotes generation of reactive oxygen species (ROS) in vitro . As a result, activities of mitochondrial respiratory chain complex I and IV and the cellular ATP level are decreased and mitochondrial morphology is damaged. FLO represses cell growth and proliferation by suppression of phosphorylation of p70S6K through AMPK/mTOR/p70S6K pathway. Furthermore, FLO also induces G0/G1 cell cycle arrest via increase of p21 levels through activating ROS/p53/p21 pathway. Moreover, the clearance of damaged mitochondria by autophagy is impaired, leading to cell proliferation inhibition and promotes cell senescence. In addition, FLO-induced upregulation of cytosolic p53 may contribute to mitophagy deficiency via regulation of Parkin recruitment. In summary, our data suggest that florfenicol is an inhibitor of mitochondrial protein synthesis that can induce noticeable cytotoxicity. Thus, these findings can be useful for guiding the proper use of FLO and the development of safe drugs.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2017
·Vol. 409
·期 28
·6643-6653
·
IF 3.431
Wang Nan,Wang Yan-Fei,Omer Ahmed M.,Ouyang Xiao-kun
A novel adsorbent based on the surface of magnetic graphene oxide-grafted cellulose nanocrystal molecularly imprinted polymers (Mag@GO-g-CNCs@MIPs) was developed for the selective extraction and fast adsorption of fluoroquinolones (FQs) from river water samples. Cellulose nanocrystals (CNCs) were grafted onto activated graphene oxide (GO), and the surfaces of the obtained magnetic GO-g-CNC particles were molecularly imprinted with polymers using ofloxacin (OFX) as a template molecule and methacrylic acid (MAA) as a functional monomer. The resulting Mag@GO-g-CNCs@MIP material was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometry, and X-ray photoelectron spectroscopy. Under optimum adsorption conditions, the Mag@GO-g-CNCs@MIPs with large specific surface area were easily collected and separated using an external magnetic field. Mag@GO-g-CNCs@MIPs exhibited an ultra-fast adsorption profile for FQs (5 min to achieve the maximum adsorption capacity of 74 mg/g), with imprinting factor values ranging from 1.5 to 3.1. High recognition selectivity towards nine FQs from real river water samples was established through coupling with high-performance liquid chromatography (HPLC), and the recovery of samples spiked with nine FQs was found to be in the range of 79.2–96.1%, with a detection limit ranging from 6.5 to 51 ng/g. Moreover, the data obtained adhered to the Freundlich isotherm model, and the adsorption kinetics followed a pseudo-second-order model. Finally, the Mag@GO-g-CNCs@MIPs could be regenerated and reused for seven consecutive cycles with only a 13% drop in adsorption capacity, indicating its effective application as a new, reusable, and selective adsorbent for the enrichment and separation of FQs from aqueous solutions.
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Biotechnology for Biofuels
·
2017
·Vol. 10
·期 1
·1-16
·
IF 5.203
Jiang Yongguang,Xiao Peng,Shao Qing,Qin Huan,Hu Zhangli,Lei Anping,Wang Jiangxin
Background Microalgae have been demonstrated to be among the most promising phototrophic species for producing renewable biofuels and chemicals. Ethanol and butanol are clean energy sources with good chemical and physical properties as alternatives to gasoline. However, biosynthesis of these two biofuels has not been achieved due to low tolerance of algal cells to ethanol or butanol. Results With an eye to circumventing these problems in the future and engineering the robust alcohol-producing microalgal hosts, we investigated the metabolic responses of the model green alga Chlamydomonas reinhardtii to ethanol and butanol. Using a quantitative proteomics approach with iTRAQ-LC–MS/MS technologies, we detected the levels of 3077 proteins; 827 and 730 of which were differentially regulated by ethanol and butanol, respectively, at three time points. In particular, 41 and 59 proteins were consistently regulated during at least two sampling times. Multiple metabolic processes were affected by ethanol or butanol, and various stress-related proteins, transporters, cytoskeletal proteins, and regulators were induced as the major protection mechanisms against toxicity of the organic solvents. The most highly upregulated butanol response protein was Cre.770 peroxidase. Conclusions The study is the first comprehensive view of the metabolic mechanisms employed by C. reinhardtii to defend against ethanol or butanol toxicity. Moreover, the proteomic analysis provides a resource for investigating potential gene targets for engineering microalgae to achieve efficient biofuel production.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-12
·
IF 4.259
Jiang Bin,Zhang Xiaoqing,Yuan Yongqiang,Qu Yuxiao,Feng Zhibiao
An aqueous two-phase system (ATPS) consisting of poly(ethylene glycol-ran-propylene glycol) monobutyl ether (UCON)/phosphate was developed for the separation of the antioxidant peptides from pepsin hydrolysate of Whey Protein Isolate (WPI). The efficiency of the separation was evaluated based on the DPPH radical scavenging activity, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP) of the separated peptides. The effects of some parameters on the partition of antioxidant peptides were investigated. An efficient separation of antioxidant peptides was achieved using ATPS with pH of 4.0, 4 mL of UCON solution (40%, w / w ), 4 mL of KH 2 PO 4 solution (15.5%, w / w ), 2 mL of WPI hydrolysate and 0.40 g/10 mL of NaCl. Reversed-phase high-performance liquid chromatography (RP-HPLC), amino acid analyzer and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to characterize the purified peptides separated by the ATPS. The peptides in top phase were less polar than those in bottom phase. More antioxidative and hydrophobic amino acids were extracted to the top phase of ATPS, and the peptides with the amino acid sequences with antioxidant activities moved to the top phase as well. In conclusion, antioxidant peptides were successfully separated from the WPI hydrolysate by UCON/phosphate ATPS.
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POLYMER BULLETIN
·
2017
·Vol. 75
·期 7
·2901-2916
·
IF 1.43
Wu Sen-Qiang,Wang Jing-Wen,Wang Gao-Qiang,Ren Hua
Polyaniline (PANI) doped with p -toluene sulfonic acid (PTSA) was synthesized by chemical oxidation method under the condition of conventional magnetic stirring (PTSA–PANI) and ultrasonic vibration (uPTSA–PANI) separately. Acrylic resin elastomer (ArE) was synthesized via radical polymerization. Novel all-organic dielectric elastomer composites (refer to the resultant composites herein as ArE/PTSA–PANI and ArE/uPTSA–PANI) were obtained by solution casting method. Chemical and microstructure characterization of the two kinds of resultant composites suggested that uPTSA–PANI possessed larger crystalline domain than that of PTSA–PANI and a unique branched structure. The dielectric properties of composites were measured in a wide frequency range, and the results demonstrated that both ArE/2.0% PTSA–PANI and ArE/2.0% uPTSA–PANI owned a high dielectric constant of more than 30 at 100 Hz, representing ten times increase with respect to neat ArE matrix (≈ 3). Moreover, it was found that ArE/2.0%uPTSA–PANI held better comprehensive dielectric properties at high frequency than that of ArE/2.0% PTSA–PANI composite; that was to say, ArE/2.0% uPTSA–PANI composite possessed not only high dielectric constant but also low dielectric loss. In addition, the thermogravimetric analysis indicated that the composite possessed better thermal stability than that of neat ArE. In addition, the elastic modulus of ArE/2.0% uPTSA–PANI composite was lower than 5 MPa.
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CHEMICAL PAPERS
·
2017
·Vol. 72
·期 1
·71-79
·
IF 1.258
Hu YunXia,Shang Fang,Liu Yuan,Wang Sui,Hu Yufang,Guo Zhiyong
In this paper, a label-free electrochemical immunosensor for ultrasensitive detection of microcystin-leucine-arginine (MC-LR) based on multi-functionalized graphene oxide was constructed. The graphene oxide has a large surface area for the immobilization of the antibody. Meanwhile, the introduction of the AuNPs and 1-butyl-3-methylimidazolium hexafluorophosphate could enhance the response of the current by improving the electrical conductivity. Thus the electrochemical immunosensor could be prepared through a one-step process and differential pulse voltammetry was employed to detect sensitively MC-LR. Under optimal conditions, the current response of the immunosensor decreased proportionally to the logarithmic concentrations of MC-LR in the range of 0.1–1000 ng/mL with a detection limit of 0.1 ng/mL (S/N = 3). This one-step label-free electrochemical immunosensor showed good performance in specificity, stability, reproducibility, and application.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2017
·Vol. 28
·期 11
·8043-8050
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IF 2.019
Chen Jianwen,Yu Xinmei,Yang Faquan,Fan Yun,Jiang Yewen,Zhou Yuexia,Duan Zhikui
High-energy-density flexible composite films, using one dimension BaTiO 3 @Ag nanofibers (BT@Ag NFs) as fillers and PVDF as polymeric matric, have been prepared by solution casting and the following hot compressing molding. The BT@Ag NFs have been prepared by electrospinning and then chemical deposition method. The dielectric constant, dielectric loss, breakdown strength and energy density were studied systematically. The maximum dielectric constant is 42.8 at 1 kHz in the nanocomposites loading with 15 vol% BT@Ag NFs, which is about 515% larger than that of the pristine PVDF (8.3 at 1 kHz). The energy density of the 2.5 vol% BT@Ag NFs/PVDF nanocomposites is 7.75 J cm − 3 at 3500 kV m − 1 , which is about 645% over the biaxially oriented polypropylenes (1.2 J cm − 3 at 6400 kV m − 1 ). The enhanced energy density may be ascribed to the Coulomb block effect. Such improvements are of potential importance for preparation of high-energy-density nanocomposites.
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POLYMER BULLETIN
·
2016
·Vol. 74
·期 8
·3109-3121
·
IF 1.371
Sun Wei,Zheng Yan,Zhang Xingyuan
Novel waterborne polyurethane (WPU) with side-chained Phenylazonaphthalene group was prepared by step-growth addition polymerization between isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), 2, 2-dimethylol propionic acid (DMPA) and a self-made azo diol, N , N -(2-hydroxyethyl)-4-phenylazo naphthylamine (HPN), as a chain extender to partially substitute for 1, 4-butanediol (BDO). 1 H nuclear magnetic resonance spectra ( 1 H NMR), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet–Visible (UV–Vis) spectroscopy were used to research the properties of HPN and HPN-WPU. The WPU latex presented obvious trans–cis photoisomerization during UV radiation and the absorption wavelength of the HPN exhibited a blue shift after attached into polyurethane chains. It needed longer irradiated time to finish isomerization due to the emulsion aggregated states, comparing with phenylazonaphthalene monomer solution and WPU dilute solution.
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PHARMACEUTICAL RESEARCH
·
2016
·Vol. 34
·期 3
·610-618
·
IF 3.26
Chao Yanhui,Liang Yuheng,Fang Guihua,He Haibing,Yao Qing,Xu Hang,Chen Yinrong,Tang Xing
Purpose DOX is one of the most potent anticancer drugs. But its short half-life and the occurrence of multi-drug resistance (MDR) markedly limit its clinical application. To solve these problems, we develop DOX loaded polymersomes (DOX polymersomes). Methods An methoxy poly(ethylene glycol)-b-poly(epsilon-caprolactone) (mPEG-b-PCL) copolymer was synthesized and used to prepare DOX polymersomes. The pharmaceutical properties of DOX polymersomes were characterized. The in vitro release profile of DOX from polymersomes was investigated. The in vitro cytotoxicity and cell uptake studies were performed on MCF-7 and MCF-7/ADR cells. The in vivo pharmacokinetic profiles were investigated on Sprague–Dawley rats. Results DOX polymersomes had a nano-scale particle size of about 60 nm with a hydrophobic membrane about 10 nm in thickness. Release of DOX from the polymersomes took place in a sustained manner. Cell experiments showed DOX polymersomes enhanced the cytotoxicity and the intracellular accumulation of DOX in MCF-7/ADR cells, compared with free DOX. In vivo pharmacokinetic study showed the DOX polymersomes increased the bioavailability and prolonged the circulation time in rats. Conclusions The entrapment of DOX in biodegradable polymersomes could enhance cytotoxicity in MCF-7/ADR cells and improve its in vivo pharmacokinetic profile.
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Science Bulletin
·
2016
·
IF 0
Hui-Zhen Cui,Ying-Qiu Gu,Xin-Xin He,Shuai Wei,Zhao Jin,Chun-Jiang Jia,Qi-Sheng Song
Iron-based composite nanostructures with ceria or titania as shell coating on naked iron spheres were successfully synthesized and used to catalyze ammonia decomposition . The structure and texture of fresh and used catalysts were characterized by transmission electron microscopy , X-ray diffraction, in situ X-ray diffraction, temperature-programmed reduction by hydrogen, and N 2 adsorption–desorption. For ammonia decomposition , the iron-based composite catalyst coated with cerium and titanium showed excellent catalytic activity compared with naked iron sphere catalyst, with the former yielding nearly 100% ammonia conversions at 650 °C and showing high stability in the catalysis test (for 60 h) at 600 °C with a space velocity of 24 , 000 cm 3 g cat − 1 h − 1 . These results showed that adding cerium and titanium played a key role in improving catalytic activity for ammonia decomposition and enabling high thermal stability .
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