METABOLIC BRAIN DISEASE
·
2018
·Vol. 34
·期 1
·173-181
·
IF 2.441
Sun Kaiyue,Bai Yuting,Zhao Rong,Guo Zijiao,Su Xiang,Li Peiqi,Yang Pengyu
The present study was designed to evaluate the effects of matrine (MAT) on scopolamine (SCOP)-induced learning and memory impairment. After successive oral administration of MAT to mice for three days at doses of 0.4, 2, and 10 mg/kg, we assessed improvements in learning and memory and investigated the mechanism of action of SCOP-induced amnesia. Donepezil at a dose of 3 mg/kg was used as a standard memory enhancer. MAT significantly improved SCOP-induced learning and memory impairment in novel object recognition and Y-maze tests at doses of 0.4, 2, and 10 mg/kg. Furthermore, MAT inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities and decreased oxidative stress in the brain, as evidenced by increased total antioxidant capacity, total superoxide dismutase levels, and catalase activities as well as decreased malondialdehyde levels. Additionally, there was a significant negative correlation between the percentage of spontaneous alternation in the Y maze and AChE activity in the cortex and hippocampus. MAT ameliorated SCOP-induced amnesia by the inhibition of both AChE/BuChE activities and oxidative stress. This study provides further evidence to encourage the development of MAT as a drug for the prevention or treatment of Alzheimer’s disease.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 30
·期 2
·1626-1636
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IF 2.324
Li Yuexuan,Duan Yugang
Silicon coupling reagent is regarded as a common additive on surface treatment of polymer due to its high bonding strength and low cost. In this paper, a series of γ-(2, 3-epoxypropoxy) propyltrimethoxysilane (KH560)-based reduced graphene oxide (RGO)@Fe 3 O 4 (KH560/RGO@Fe 3 O 4 ) composites with different ratio of Fe 3 O 4 nanoparticles (NPs) are synthesized by a facile hydrothermal method. It is confirmed that the silicon reagent KH560, as a hopeful candidate for increasing the RGO lattice defects, is favorable to improve the electromagnetic wave absorption. Meanwhile, the microwave attenuation mechanism of KH560/RGO@Fe 3 O 4 composite suggests that the dielectric loss mainly causes by multiple Debye dipolar relaxation and its magnetic loss comes from the eddy-current effect of Fe 3 O 4 NPs over the high frequency range. In consequence, the KH560/RGO@Fe 3 O 4 composite endows the excellent absorption performance, the reflection loss (RL) value is optimized to − 25 dB at 14.1 GHz with a thickness of 3 mm and the maximum frequency bandwidth for RL < − 10 dB is 4.1 GHz with a thickness of 4 mm.
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Nano Research
·
2018
·Vol. 11
·期 7
·3762-3770
·
IF 7.994
Sun Panpan,Zhang Yan,Ran Xiang,Liu Chaoying,Wang Zhenzhen,Ren Jinsong,Qu Xiaogang
Though phytochemicals are a promising alternative to traditional antibiotics for combating resistant bacteria, the low water solubility and lack of selectivity seriously hinder their widespread applications. Herein, we constructed a hyaluronidase-activated “on-demand” delivery nanocarrier to encapsulate plant essential oils (PEOs) for the synergistic treatment of multidrug-resistant bacteria. The bioavailability and selectivity of PEOs was enhanced and the antibacterial effect was significantly improved by combining with the photothermal effect of the nanocarrier. This antibacterial system was successfully applied for healing methicillin-resistant Staphylococcus aureus -infected wound with negligible cytotoxicity and biotoxicity in mice. Given the increasing risk of antibiotic resistance, we believe that this phytochemical-encapsulated nanoplatform would provide a long-term solution and be a new powerful tool for skin-associated bacterial infections.
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Emerging Microbes & Infections
·
2018
·
IF 6.032
Jin-xin Zheng,Zhi-wei Lin,Xiang Sun,Wei-hong Lin,Zhong Chen,Yang Wu,Guo-bin Qi,Qi-wen Deng,Di Qu,Zhi-jian Yu
This study investigated the characteristics and mechanisms of eravacycline resistance and heteroresistance in clinical Klebsiella pneumoniae isolates. A total of 393 clinical K. pneumoniae isolates were collected and subjected to eravacycline and tigecycline MIC determinations using the agar dilution method. Eravacycline heteroresistance was assessed by a population analysis profile (PAP). The expression levels of efflux pumps and their regulators were determined by quantitative reverse-transcription PCR (qRT-PCR). This study identified 67 eravacycline-nonsusceptible isolates; among the extended-spectrum β-lactamase (ESBL)-positive isolates, eravacycline-nonsusceptible isolates were detected more frequently than tigecycline-nonsusceptible isolates (21.7% vs. 9.4%, p = 0.001). The study sample was observed to include 20 K. pneumoniae isolates with eravacycline heteroresistance. Compared to the reference strain, oqxA or oqxB overexpression was observed in nine eravacycline-nonsusceptible isolates (range, 35.64–309.02-fold) and 13 eravacycline-heteroresistant isolates (8.42–296.34-fold). The overexpression of macA or macB was detected in 12 eravacycline-heteroresistant isolates (3.23–28.35-fold). Overexpression of the efflux pump regulator gene ramA was observed in 11 eravacycline-nonsusceptible isolates (3.33–94.05-fold) and 18 eravacycline-heteroresistant isolates (3.89–571.70-fold). The eravacycline MICs were increased by one–fourfold by overexpression of oqxAB or macAB in three eravacycline-sensitive isolates. In conclusion, the overexpression of OqxAB and MacAB efflux pumps and the transcriptional regulator RamA were suggested to be involved in K. pneumoniae eravacycline resistance and heteroresistance.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 21
·14989-14997
·
IF 2.993
Jia Qin,Geng Zhi-Qin,Liu Yang,Wang Wen,Han Cai-Qin,Yang Guo-Hai,Li Haitao,Qu Lu-Lu
A disposable solid-phase extraction (SPE) membrane was developed for rapid removal and sensitive surface-enhanced Raman scattering (SERS) detection of antibiotics in water samples. The membrane was fabricated on commercially available SPE column by filtration of the activated carbon modified with silver nanoparticles (Ag NPs/AC). The prepared SPE membrane exhibited outstanding preconcentration ability due to the high adsorption properties of AC, and excellent ability to enhance Raman signal resulting from “hot spots” between the embedded Ag NPs, improving the sensitivity of SERS detection. A detection limit (LOD) of 5.0 × 10 −11 and 1.6 × 10 −10 M was achieved for rhodamine 6G and p -aminothiophenol. In addition, the membrane exhibited high reproducibility with spot-to-spot variation in SERS spectral intensity less than 15%. Based on the membrane, the qualitative and quantitative analysis of the antibiotics in aqueous solution was accomplished with the LOD at nM level, demonstrating the feasibility of the disposable SPE membrane for in situ rapid preconcentration and detection.
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Science China-Chemistry
·
2018
·Vol. 61
·期 9
·1159-1166
·
IF 4.448
Chen Miao,Zhang Wei-Guo,Li Jia-Wei,Hong Chun-Yan,Zhang Wen-Jian,You Ye-Zi
pH- and reductive-responsive prodrug nanoparticles are constructed via a highly efficient strategy, polymerization-induced selfassembly (PISA). First, reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(diisopropylamino) ethyl methacrylate (DIPEMA) and camptothecin prodrug monomer (CPTM) using biocompatible poly( N -(2-hydroxypropyl) methacrylamide) (PHPMA-CPDB) as the macro RAFT agent is carried out, forming prodrug diblock copolymer PHPMA-P (DIPEMA- co -CPTM). Then, simultaneous fulfillment of polymerization, self-assembly, and drug encapsulation are achieved via RAFT dispersion polymerization of benzyl methacrylate (BzMA) using the PHPMA-P(DIPEMA- co -CPTM) as the macro RAFT agent. The prodrug nanoparticles have three layers, the biocompatible shell (PHPMA), the drug-conjugated middle layer (P(DIPEMA- co -CPTM)) and the PBzMA core, and relatively high concentration (250 mg/g). The prodrug nanoparticles can respond to two stimuli (reductive and acidic conditions). Due to reductive microenvironment of cytosol, the cleavage of the conjugated camptothecin (CPT) within the prodrug nanoparticles could be effectively triggered. pH-Induced hydrophobic/ hydrophilic transition of the PDIPEMA chains results in faster diffusion of GSH into the CPTM units, thus accelerated release of CPT is observed in mild acidic and reductive conditions. Cell viability assays show that the prodrug nanoparticles exhibit well performance of intracellular drug delivery and good anticancer activity.
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METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2018
·Vol. 49
·期 4
·2071-2076
·
IF 1.834
Yan Hengwei,Yang Jianhong,Liu Zhanwei,Wang Chengzhi,Ma Wenhui
The cryolite ratio (CR) is an important parameter for the electrolyte in aluminum reduction cells. The measurement method for the CR of the KF-NaF-AlF 3 system acid (CR < 3) electrolyte by means of electrical conductivity was initially developed, and the formula for calculating the CR was deduced. This method has the advantages of simple operation and high precision. In addition, the relative standard deviations (RSD) of the measurement are < 1.2 pct, and the analysis error of the NaF or KF content has little effect on the determination of the CR.
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TRIBOLOGY LETTERS
·
2018
·Vol. 66
·期 2
·1-10
·
IF 2.182
Qin Songlv,Cui Mingjun,Dai Zhendong,Qiu Shihui,Zhao Haichao,Wang Liping,Zhang Afang
A facile method is proposed to prepare poly- o -phenylenediamine (PoPD) noncovalent functionalized graphene (G)-reinforced polyimide (PI) nanocomposites. PoPD-G exhibited excellent dispersibility in various organic solvents. The structures of PoPD-G were characterized by Raman and UV spectrum, which verified the π – π interactions between PoPD and G. The effective exfoliation of graphene nanosheets was investigated by observation of the morphology of PoPD-G with SEM, SPM, and TEM. Compared to PI/G composites, the interfacial adhesion between graphene nanosheets and PI matrices promoted efficient stress transfer from PI chains to PoPD-G nanofillers. Polyimide nanocomposites with different incorporations of PoPD-G exhibited outstanding thermal properties. It is interesting to note that only 0.5 wt% PoPD-G-reinforced PI composites increased by 20.8% in hardness, enhanced by 84.0% in storage modulus, and reduced by 72.8% in wear rate compared with neat PI. The eminent enhancement was attributed to the facile dispersion of graphene nanosheets and strong interface adhesion between PI and PoPD-G.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 12
·10071-10081
·
IF 2.324
Geng Xianwei,Yi Ruowei,Yu Zhiming,Zhao Cezhou,Li Yinqing,Wei Qiuping,Liu Chenguang,Zhao Yinchao,Lu Bing,Yang Li
Nitrogen-doped graphene (NG) is a promising material for fabricating high-performance lithium–sulfur batteries. Here a facile hydrothermal method was used to synthesize the NG and then the composite of NG and SWCNT (NG/SWCNT) was obtained by mixing with single-walled carbon nanotubes (SWCNT) via a simple ultrasonic method. Finally, the NG/SWCNT-sulfur composite (NG/SWCNT-S) is synthesized via an isothermal method that enables rapid vapor infiltration of sulfur into carbon nanotubes. The resulting sulfur-containing cathode shows a good capacity performance, reaching high initial capacities of 1199.6 mAh g −1 at 0.1 C and 725.2 mAh g −1 at 1 C. The optimized electrochemical performance can be attributed to the NG addition which leads to an effective improvement of sulfur utilization and seizing polysulfides during cycling. Moreover, we show that the vapor infiltration method based on the thermodynamics of capillary condensation on nanoscale surfaces offers a new idea for assembling cathode, compared to the traditional melt infiltration method.
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Frontiers of Environmental Science & Engineering
·
2018
·Vol. 12
·期 3
·1-10
·
IF 1.961
Wu Zhichao,Zhang Chang,Peng Kaiming,Wang Qiaoying,Wang Zhiwei
Membrane technology for oil/water separation has received increasing attention in recent years. In this study, the hydrophilic/underwater superoleophobic membrane with enhanced water permeability and antifouling ability were fabricated by synergistically assembling graphene oxide (GO) nanosheets and titanium dioxide (TiO 2 ) nanotubes for oil/water separation. GO/TiO 2 membrane exhibits hydrophilic and underwater superoleophobic properties with water contact angle of 62° and under water oil contact angle of 162.8°. GO/TiO 2 membrane shows greater water permeability with the water flux up to 531 L/ (m2$h$bar), which was more than 5 times that of the pristine GO membrane. Moreover, GO/TiO 2 membrane had excellent oil/water separation efficiency and anti-oil-fouling capability, as oil residual in filtrate after separation was below 5 mg/L and flux recovery ratios were over 80%.The results indicate that the intercalation of TiO 2 nanotubes into adjacent GO nanosheets enlarged the channel structure and modified surface topography of the obtained GO/TiO 2 membranes, which improved the hydrophilicity, permeability and anti-oil-fouling ability of the membranes, enlightening the great prospects of GO/TiO 2 membrane in oil-water treatment.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 135
·期 5
·2869-2877
·
IF 2.209
Wang Dongqing,Sui Jian,Qi Di,Deng Shuping,Wei Yongteng,Wang Xin,Lan XiaoZheng
Confinement effect of nanopores on phase transition of docosane ( n -C 22 H 46 , C 22 ) is studied using differential scanning calorimetry (DSC) and temperature-dependent powdered X-ray diffractions (XRD). The bulk C 22 has a stable rotator phase R I and R II . In the pores of CPGs, SBA-15, C-SBA-15, KIT-6, and MCM-41, the transition temperatures of solid–solid ( T s ) and solid–liquid ( T m ) transitions of C 22 are depressed. The depression of the transition points (Δ T s , Δ T m ) has a linear relation with the reverse diameter. However, the Δ T m values seemingly show weak relation with the polarity of the pore walls but to vary with the pore dimensionality. According to XRD analysis, C 22 confined in CPG (11.5 nm) and SBA-15 (14.4 nm) present low temperature phase and rotator phase as the bulk, but the lamellar packing of molecules is heavily disturbed in the small pores.
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JOURNAL OF SOLUTION CHEMISTRY
·
2018
·Vol. 47
·期 4
·705-714
·
IF 1.401
Li Qiang,Liu Bijun,Mu Wanjun,Yu Qianhong,Tian Yin,Liu Guoping,Yang Yuchuan,Li Xingliang,Luo Shunzhong
Glufosinate, an analogue of glutamic acid (also known as phosphinothricin), is an important herbicide. The protonation constants of glufosinate were determined by means of potentiometric titrations at variable temperatures with ionic strength 0.5 mol·L −1 (NaCl solution). The heat effects of the protonation reactions of glufosinate were measured by direct calorimetry. NMR spectroscopies have demonstrated that the first protonation site occurs on the nitrogen atom in the amino group, followed by one of the oxygen atoms in the phosphono group, and finally the carboxyl oxygen atom. This trend is in good agreement with the enthalpy of protonation and crystal structure results. These data will help to predict the speciation of glufosinate in physiological systems.
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