ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 23
·19011-19020
·
IF 2.741
Zhang Zhijia,Xing Defeng,Zhao Xin,Han Xiaojun
We demonstrated a method to form magnetic antimicrobial POHABA (poly- N , N ′-[(4,5-dihydroxy-1,2-phenylene)bis(methylene)]bisacrylamide)-based core-shell nanostructure by free-radical polymerization of OHABA on the Fe 3 O 4 core surface. The magnetic antimicrobial agent Fe 3 O 4 @POHABA can be used in domestic water treatment against bacterial pathogens. The thickness of POHABA shell could be controlled from 10.4 ± 1.2 to 56.3 ± 11.7 nm by the dosage of OHABA. The results of antimicrobial-activity test indicated that POHABA-based core-shell nanostructure had broad-spectrum inhibitory against Gram-negative, Gram-positive bacteria and fungi. The minimum inhibitory concentration (MIC) values of Fe 3 O 4 @POHABA nanostructure against Escherichia coli and Bacillus subtilis were both 0.4 mg/mL. Fe 3 O 4 @POHABA nanostructures responded to a permanent magnet and were easily recycled. Fe 3 O 4 @POHABA nanoparticles retained 100% antimicrobial efficiency for both Gram-negative and Gram-positive bacteria throughout eight recycle procedures.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 14
·8455-8464
·
IF 2.599
Qin Jingjing,Chen Lang,Zhao Chenghui,Lin Qixiang,Chen Shaowei
A novel porous aerogel of cellulose nanofiber (CNF)/cationic water-soluble poly[9,9-bis[3′-( N,N -dimethy)- N -ethylammonium)propyl)-2,7-fluorene- alt -1,4-phenylene]dibromide (CPFD) is prepared by freeze drying. CNF can effectively prevent aggregation of the conjugated polymer CPFD backbones. The CNF/CPFD hybrid aerogel is use for the detection of nitroaromatic (NAC) vapors. Due to the porous structure, the CNF/CPFD hybrid aerogel possesses a large number of accessible cavities, which could be sufficiently large to allow the diffusion of NAC vapors into the aerogel. As a result, the CNF/CPFD aerogel sensor shows high sensitivity toward NAC vapors. For 120-s exposure, the fluorescence quenching efficiency of the CNF/CPFD aerogel sensor toward 2,4-dinitrotoluene vapor is up to 85.9%, which is much larger than that of the spin-cast CPFD film. Furthermore, the sensing performance of the CNF/CPFD hybrid aerogel is not heavily dependent on the thickness, and the sensing process of the CNF/CPFD aerogel sensor is reversible.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Analytical Science and Technology
·
2017
·Vol. 8
·期 1
·1-9
·
IF 0
Oladosu Najeem O.,Abayomi Akeem A.,Zhang Xiang,Olayinka Kehinde O.,Alo Babajide I.,Deng Anping
The substitution of hazardous analytical reagents such as Cd with benign alternatives for chemical determination is one of the principles of green chemistry. An eco-friendly Zn reduction method for nitrate determination was developed to achieve this end.Online zinc reduction-sequential injection analysis (ZnR-SIA) protocol was developed for the determination of nitrogen (N) species in the Lagos Lagoon sediments by modification of some standard methods.The novel application of boric acid-borate buffer employed in borate-buffered granular Zn reduction suppressed gas evolution from the Zn micro-column, making the Zn reduction adaptable to online use, unlike the frequently used ammonia-ammonium buffer. Further results showed that the sampling rate for the two-zone stack was 65 h−1. The boric acid-borate buffer offered 5.9-fold and 1.3-fold of the instrument response given by the ammonia-ammonium buffer at 0.50 and 5.0 mg N L−1 respectively. The method detection limits of the ZnR-SIA for the three matrices studied were 24.6 μg N L−1 for reagent water, 0.383 mg N kg−1 for KCl-extractable nitrate, and 3.18 mg N kg−1 for total nitrogen. The average recovery of nitrate-N in matrix samples was 94.7%, and its precision was 4.52%. The average recoveries of total N in blanks and matrix samples were 97.9 and 93.2% respectively.The method accuracies demonstrated the suitability of the ZnR-SIA for sediment N determination. Zn reduction is recommended where sustainable development is desired and is a potential substitute for the standard Cd reduction owing to Cd toxicity.
✓ 已验证
DOI
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 7
·2181-2189
·
IF 4.58
He Yanfang,Niu Xiangheng,Shi Libo,Zhao Hongli,Li Xin,Zhang Wenchi,Pan Jianming,Zhang Xifeng,Yan Yongsheng,Lan Minbo
The authors describe a photometric method for the determination of free cholesterol based on the oxidation of cholesterol by the catalytic action of the enzyme cholesterol oxidase. The hydrogen peroxide formed is used to oxidize the chromogenic compound 3,3′,5,5′-tetramethylbenzidine (TMB) by exploiting the peroxidase-like activity of carbon nanotube-supported Prussian blue (PB). This enzyme mimic was synthesized from a mixture of ferric chloride and hexacyanoferrate(III) in the presence of intrinsically reducing multi-walled carbon nanotubes. The composite can trigger the formation of a blue-green dye from TMB in the presence of H 2 O 2 . The findings were exploited to design a photometric (652 nm) assay that has a linear response in the 4 to 100 μM cholesterol concentration range and a 3 μM detection limit. The practicability of the method was verified by the successful analysis of free cholesterol in human blood samples.
Schematic of a carbon nanotube-supported Prussian blue (PB/MWCNT) hybrid used as a promising peroxidase mimic. It has the advantages of low cost, simple synthesis, high activity, and good stability. PB/MWCNTs along with cholesterol oxidase (ChOx) are used in a colorimetric assay for the determination of free cholesterol.
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 3
·1704-1716
·
IF 2.302
Wu Huiqing,Jia Wei,Liu Yuejun
Imidazolium-type hybrid alkaline anion exchange membranes (Im-hybrid AAEMs) were prepared based on poly(2-bromomethyl-,6-methyl-1,4-phenylene oxide) matrix employing 1-vinylimidazole and modified hollow mesoporous silica spheres (mHMSS). 1-Vinylimidazole, which is introduced into the casting system via pre-functionalization, can not only produce imidazolium side groups which impart the resultant membrane with an anion conduction capability, but also help form a crosslinked membrane structure via irradiation with ultraviolet (UV) light, contributing to the membrane stability. Hollow mesoporous silica particles are functionalized with amino groups and then incorporated into the membrane for the enhanced compatibility and membrane stability. The Im-hybrid AAEMs exhibit an improved alkaline stability at a high pH solution and elevated temperature. The effects of the amount of 1-vinylimidazole, UV crosslinking time, and loading of mHMSS on the membrane properties were investigated. The results illustrate that Im-hybrid AAEMs with the mHMSS loading of 0.5 wt% possess the best overall performance including enhanced membrane stability and suitable conductivity, which are critical for alkaline fuel cells applications.
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2016
·Vol. 23
·期 6
·3717-3735
·
IF 3.195
Liu Ting,Xue Feng,Ding Enyong
Graft modification is an excellent way to prepare cellulose nanocrystals (CNCs) with various functions. In this work, different water-soluble macro reversible addition fragmentation chain transfer (macroRAFT) agents were used to mediate grafting of polyacrylamide with cellulose nanocrystals. Fourier-transform infrared spectroscopy, 13 C solid-state nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy, and elemental analysis were used to characterize the presence of polyacrylamide and quantify its content on the modified cellulose nanocrystals. The results show that two amphiphilic macroRAFTs, namely St 5 AA 14 RAFT and St 7 AA 14 RAFT, increased the weight ratio of polyacrylamide on the modified cellulose nanocrystals, whereas a corresponding hydrophilic macroRAFT (AA 14 RAFT) impeded growth of the polymer chains on the cellulose nanocrystals. Examination of the structure of the graft products and the cleaved polyacrylamide chains revealed that the amphiphilic macroRAFTs were involved in the graft reaction through effective chain transfer, thereby increasing the weight ratio of polyacrylamide on the modified CNCs.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2016
·Vol. 408
·期 29
·8515-8528
·
IF 3.125
Lu Nan,Wang Ting,Zhao Pan,Zhang Lianjun,Lun Xiaowen,Zhang Xueli,Hou Xiaohong
In the presented work, metal-organic framework (MOF) material MIL-101(Cr) (MIL, Matérial Institute Lavoisier) was used as a sorbent for vortex assisted dispersive micro-solid-phase extraction (VA-D-μ-SPE) of trace amount of metronidazole (MNZ), ronidazole (RNZ), secnidazole (SNZ), dimetridazole (DMZ), tinidazole (TNZ), and ornidazole (ONZ) in different environmental water samples. Ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) was used to quantify the target analytes. The extraction conditions, including type of sorbents, amount of MIL-101(Cr), solution pH, extraction method, extraction time, effect of salt, and elution conditions were investigated. Upon the optimal conditions, the developed method showed an excellent extraction performance with the average recovery ranging from 75.2 to 98.8 %. Good sensitivity levels were achieved with the detection limits of 0.03∼0.06 μg/L and the quantitation limits of 0.09∼0.20 μg/L. The linear ranges were varied from 0.1 to 20 for SNZ and ONZ and from 0.2 to 40 μg/L for MNZ, RNZ, DMZ, and TNZ ( r
2 > 0.992), and repeatability of the method was satisfactory with the relative standard deviations (RSD) <8 %. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of 5-nitroimidazoles (5-NDZs) in 12 real water samples, showing the positive findings of MNZ and TNZ ranging from 0.3 to 1.0 μg/L. Furthermore, molecular docking was applied to explain the molecular interactions and free binding energies between MIL-101(Cr) and 5-NDZs, providing a deep insight into the adsorption mechanism. The proposed method exhibited the advantages of simplicity, rapidly, less solvent consumption, ease of operation, higher sensitivity, and lower matrix effect.
Schematic diagram of the extraction process and molecular docking investigation
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Waste and Biomass Valorization
·
2016
·Vol. 8
·期 7
·2443-2450
·
IF 0.915
Zhang Kai,Wu Shubin,Yang He,Li Gang
Cassava residue was proposed as a raw material for the production of ethylene glycol (EG) via a one-pot hydrothermal reaction in the present study. Various mixed catalysts consisting of activated carbon supported Ru (Ru/AC) and a tungsten species were used for the conversion of cassava residues, and the effects of various reaction conditions on the catalytic performance were investigated. When the reaction was carried out at 245 °C for 60 min, the Ru/AC–H 2 WO 4 mixed catalyst showed a EG yield of 53.1 % with a total polyols yield of 80 %, which was confirmed to be the most active among the prepared catalysts. The excellent catalytic performance using cassava residue as the feedstock mainly resulted from a high content of carbohydrates and a low amount of lignin in cassava residues. Furthermore, the Ru/AC–H 2 WO 4 catalyst also showed reasonable stability during the hydrothermal conversion of cassava residues for EG production.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 5
·1445-1451
·
IF 4.58
Liu Shun,Lai Guosong,Zhang Haili,Yu Aimin
A nanocomposite prepared from reduced graphene oxide (rGO) and silver nanoparticles (AgNPs) is used in an electrochemical aptasensor for the sensitive and selective determination of the antibiotic chloramphenicol (CAP). The nanocomposite was obtained by electrostatic assembly of AgNPs on the surface of polyelectrolyte-functionalized rGO and then used to modify a glassy carbon electrode. The biosensor is then obtained by immobilizing the aptamer against CAP. When incubated with solutions of CAP, the sensor surface is loaded with CAP due to aptamer recognition. The captured CAP can be electrochemically reduced to yield a current that is strongly enhanced as a result of the excellent electrocatalysis property of the graphene/AgNP-nanocomposite. Under optimum conditions, the calibration plot is linear in the 0.01 to 35 μM concentration range, with a 2 nM detection limit (at 3σ). The sensor is reproducible, stable, selective over homologous interferents, and performs excellently when analyzing CAP in milk samples.
A graphene/silver nanoparticle-based electrochemical aptasensor is designed for the selective determination of the antibiotic chloramphenicol (CAP). The excellent electrocatalytic reduction of CAP specifically captured onto the electrode surface enables the sensitive electrochemical signal transduction of the biosensor by linear sweep voltammetry (LSV).
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2017
·Vol. 74
·期 10
·4329-4348
·
IF 1.43
Zhou Jinfang,Chen Pei,Shi Qian,Wang Ruiqiang,Chen Xinbing,An Zhongwei
New poly(arylene ether sulfone) (PAES)-based anion-exchange membranes with side-chain aromatic benzyltrimethyl ammonium are synthesized, and their cross-linked membranes are prepared using tetramethyl alkylene diamine as a cross-linking agent. The new side-chain-type PAES-based membrane (Q) has acceptable hydroxide conductivity ( σ ) of 34 mS cm −1 (80 °C) and high chemical stability in hot alkali solution. Compared with Q, the corresponding series of cross-linked membranes exhibit much higher performance, such as higher dimensional stability and chemical stability, better oxidative stability, and lower methanol permeability ( P
M ). Among them, N , N , N ′, N ′-tetramethyl-1,6-diaminohexane-based cross-linked membrane (6CQ20) with IEC of 1.29 meq g −1 shows reasonably high σ of 35 mS cm −1 (80 °C) and low P
M of 0.20 × 10 −6 cm 2 s −1 , and displays high alkaline stability against alkali treatment at 60 °C for 216 h with small reduction in hydroxide conductivity by only 14%.
✓ 已验证
产品关联
DOI
高影响因子
METABOLIC BRAIN DISEASE
·
2017
·Vol. 32
·期 3
·789-798
·
IF 2.297
Wu Xiang,Chen Huixin,Huang Chunhui,Gu Xinmei,Wang Jialing,Xu Dilin,Yu Xin,Shuai Chu,Chen Liping,Li Shun,Xu Yiguo,Gao Tao,Ye Mingrui,Su Wei,Liu Haixiong,Zhang Jinrong,Wang Chuang,Chen Junping,Wang Qinwen,Cui Wei
Post-operative cognitive dysfunction (POCD) is associated with elderly patients undergoing surgery. However, pharmacological treatments for POCD are limited. In this study, we found that curcumin, an active compound derived from Curcuma longa , ameliorated the cognitive dysfunction following abdominal surgery in aged mice. Further, curcumin prevented surgery-induced anti-oxidant enzyme activity. Curcumin also increased brain-derived neurotrophic factor (BDNF)-positive area and expression of pAkt in the brain, suggesting that curcumin activated BDNF signaling in aged mice. Furthermore, curcumin neutralized cholinergic dysfunction involving choline acetyltransferase expression induced by surgery. These results strongly suggested that curcumin prevented cognitive impairments via multiple targets, possibly by increasing the activity of anti-oxidant enzymes, activation of BDNF signaling, and neutralization of cholinergic dysfunction, concurrently. Based on these novel findings, curcumin might be a potential agent in POCD prophylaxis and treatment.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 4
·2434-2442
·
IF 2.599
Li Wenkai,Xie Danhua,Song Binglei,Feng Lin,Pei Xiaomei,Cui Zhenggang
As structure-directing agents, the molecular structure of surfactants is critical for determining the properties of prepared mesoporous materials. Using dehydroabietic acid as a starting material, a series of rosin-based Gemini surfactants (abbreviated as R- n -R, n = 3, 6, 8 and 10, indicating the carbon atom number contained in the spacer) were synthesized and applied as templates in the preparation of ordered mesoporous silica. The structures and morphologies of the samples were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and N 2 adsorption–desorption. The R- n -R surfactants feature rigid tricyclic hydrophobic groups with large volumes, which are beneficial for the formation of a three-dimensional cubic phase. Furthermore, the spacer length was found to have a tremendous effect on the structure of the prepared mesoporous silica materials. The head group of R-3-R, which has a short spacer, is excessively charged, leading to silica nanoparticles with an irregular morphology and a rather low BET surface area. With longer spacer lengths, R-6-R, R-8-R and R-10-R are conducive to generating silica nanoparticles with a novel dumbbell-like morphology and with higher BET surface areas of 1171, 1096 and 1186 m 2 g −1 , respectively. The results demonstrate the particularities of the Gemini surfactant structure in the preparation of mesoporous silica nanoparticles with novel morphologies, and the details of the molecular interactions that occur in the condensation of silicate anions are also revealed.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）