CHEMICAL GEOLOGY
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2019
·
IF 3.618
Ying Wang,Xiu Yuan,Xiaomin Li,Fangbai Li,Tongxu Liu
Cytochrome c ( c -Cyts), as a key protein involved in extracellular electron transfer , plays an important role in the microbial Fe(II)-oxidizing process. In this study, due to their similar structure with the outer membrane protein of microorganisms , the equine c -Cyts was employed as a model protein to examine the impact of different organic ligands on the redox kinetics between Fe(II) and c -Cyts using the rapid stopped-flow spectrometer. Our results suggest that the presence of organic ligands will significantly accelerate the reaction between c -Cyts and Fe(II), with reaction rates obtained in the following order: EDTA > citric acid (Cit) > NTA > malonic acid (Mal) > glycine amino acid (Gly) > acetate acid (Ace) > control. It was also found from the kinetic modeling results that the reduction rate of c -Cyts by Fe(II)-ligands was closely correlated to the complex constant between Fe(II) and each ligand, and the reduction rate constants of c -Cyts by Fe(II)L species (L represents “ligands”). Further analysis on the ligand structure indicates that the reaction rate constants are highly correlated with the complex constants of Fe(II)-ligand and the reduction rate constants of c -Cyts by Fe(II)L species ( k 3 ) for Group I (Gly, NTA, and EDTA) and Group II (Cit, Mal, and Ace). The results of midpoint potentials of all Fe(II)-ligands obtained through cyclic voltammetry (CV) experiments were ranked as Ace < Gly < NTA < control < Mal < EDTA < Cit, indicating that the redox potentials of Fe(II) complexes in the same group with similar structures were positively correlated with Fe(II)-ligand complex constants. The reorganization energy change of the electron-transfer reaction resulting from the different Fe(II)-ligand structures may contribute significantly more than does the Gibbs free energy (Δ G ) to the reaction kinetics of Fe(II)-ligand and c -Cyts.
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Food Bioscience
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2019
·
IF 3.22
Biao Yuan,Cong Zhao,Chen Cheng,De-chun Huang,Shu-jie Cheng,Chong-jiang Cao,Gui-tang Chen
Grifola frondosa protein was hydrolysed using Alcalase, and the resulting hydrolysates (CGFP) were filtered using 5 and 1 kDa nominal cut-off ultrafiltration membranes and separated using Sephadex gel chromatography . Two main fractions, named GFP-1 and GFP-2 were obtained. CGFP-Fe and GFP-Fe were synthesized using ferrous chelation. Results showed that the GFP-2 fraction with molecular weight of 963 Da had the highest Fe(II) chelating activity (2680 ± 40 μg/g). UV spectrum showed that the Fe(II) shifted the maximum absorption to shorter wavelengths. The peptides measured using FTIR showed that the GFP-Fe peptide and the un-chelated peptide had different C–O and C= O absorption peaks. The effects of CGFP, CGFP-Fe, GFP2-2 and GFP-Fe on splenocytes proliferation and cytokines secretion were studied in vitro . Both the GFP-2 and GFP-Fe had good immune-enhancing activity. Furthermore, GFP-Fe showed an ability to promote the proliferation of splenocytes and peritoneal macrophages. The iron-chelating peptide of Grifola frondosa still maintained its immune enhancing activity after in vitro gastrointestinal digestion. The results suggested that GFP-Fe might be beneficial as a new iron supplement and as an immunological enhancement .
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
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IF 2.931
Zhenghong Zhao,Tianran Lin,Wenren Liu,Li Hou,Fanggui Ye,Shulin Zhao
Zeolitic imidazolate framework-8 (ZIF-8) has become one of the most typical examples of nanostructures for multi-enzyme immobilization due to its economical, mild and easy synthesis process. However, ZIF-8 nanocrystals are easily decomposed under acidic conditions. To solve this problem, the Fe-polydopamine (Fe-PDA) was bonded with ZIF-8 surface to form [email protected] hybrid shell with good stability. Based on this, we developed glucose [email protected] @Fe-PDA ( [email protected] @Fe-PDA) integrated nanozymes (INAzymes) with cascade reactions via a mild and environmentally friendly method. In order to synthesize the INAzymes, GOx was first embedded in ZIF-8 by coprecipitation ( [email protected] ), and then [email protected] was bonded with Fe-PDA, which acted as a peroxidase mimic. The [email protected] hybrid shell protected the INAzymes nanostructure from degradation under acidic conditions, which results in good chemical stability of the [email protected] @Fe-PDA. In the INAzymes system, glucose is converted to gluconic acid by GOx in the presence of oxygen to produce H 2 O 2 as an intermediate. The H 2 O 2 reacts rapidly with Fe-PDA to generate OH, which oxidizes 3,3′,5,5′-tetramethylbenzidine (TMB). The UV absorbance of oxidized TMB is directly proportional to the glucose concentration, and has a good linear relationship in the range of 5.0–100.0 μM glucose with detection limit of 1.1 μM. The INAzymes system has been successfully applied to rapid colorimetric detection of blood glucose levels. The INAzymes system exhibits high catalytic activity, excellent sensitivity, and enhanced chemical stability, playing great promise in clinical diagnosis and biosensing.
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高影响因子
Micro & Nano Letters
·
2019
·Vol. 14
·期 9
·976-979
·
IF 0.975
Wen Zeng,Qiqi Yang,Bin Shao,Donglin Guo,Chunhong Li,Yilong Ma,Xueguo Yin,Sibo Zhao,Kejian Li
The monodisperse Fe@SiO 2 core-shell nanocapsules were synthesised via hydrothermal reaction followed with heat treatment. Nanostructures were characterised by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The magnetic properties of Fe@SiO 2 nanocapsules were evaluated with magnetic property measurement system. The results show that Fe@SiO 2 core-shell nanocapsules are highly monodispersed. The silica thickness of Fe@SiO 2 nanocapsules increased from 10–20 to 25–35 nm with increasing tetraethyl orthosilicate (TEOS) amount. In the Fe@SiO 2 nanocapsules prepared with 900 μl TEOS, as the reaction temperature increases, the mean particle size of Fe@SiO 2 nanocapsules increases from 328 to 546 nm. It is remarkable that the saturation magnetisation of Fe@SiO 2 nanocapsules decreases with increasing silica thickness. However, the coercivity of nanocapsules has less influence with the variation of silica thickness and particles’ length.
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INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Jiang-Yan Xue,Fei-Long Li,Zhong-Yin Zhao,Cong Li,Chun-Yan Ni,Hong-Wei Gu,David James Young,Jian-Ping Lang
Design and synthesis of non-noble metal electrocatalysts with high activity and durability for the electrolysis of water is of great significance for energy conversion and storage. In this work, we prepared a series of Fe-doped MoS2 nanomaterials by simple one-pot solvothermal reactions of (NH4)2MoS4 with FeCl3·6H2O. An optimized working electrode of Fe-MoS2-5 displayed high hydrogen evolution reaction (HER) activity with a relatively small overpotential of 173 mV to achieve a current density of 10 mA cm–2 in 0.5 M H2SO4, along with no significant change in catalytic performance even after 1000 cyclic voltammetry (CV) cycles. Fe-MoS2 nanoparticles on nickel foam (NF; denoted as Fe-MoS2/NF) exhibited an overpotential of 230 mV at 20 mA cm–2 for the oxygen evolution reaction (OER) and 153 mV at 10 mA cm–2 for the HER in 1.0 M KOH electrolyte. Fe-MoS2/NF was stable for more than 140 h under these conditions. Furthermore, the two electrode system of Fe-MoS2/NF (anode)//Fe-MoS2/NF (cathode) electrodes demonstrated excellent electrocatalytic activity toward overall water splitting with a low potential of 1.52 V at 10 mA cm–2 in 1.0 M KOH electrolyte.
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ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Yuxue Ding,Jiaxun Wan,Zihao Zhang,Fang Wang,Jia Guo,Changchun Wang
The anticancer therapy on the basis of reactive oxygen species (ROS)-mediated cellular apoptosis has achieved great progress. However, this kind of theraputic strategy still faces some challenges such as light, photosensitizer and oxygen (O2) dependence. In this article, a ROS-mediated anticancer therapy independent of light, photosensitizer and oxygen was established based on a Fe2+-induced ROS-generating nanosystem. First, artemisinin (ART) was loaded in porous magnetic supraparticles (MSP) by a nanodeposition method. Then, the poly(aspartic acid)-based polymer, which consisted of dopamine, indocyanine green, and polyethylene glycol side chain, was coated onto the surface of ART-loaded MSP. When the nanoparticles entered into cancer cells, a reaction of Fe2+-mediated cleavage of the endoperoxide bridge contained in ART occurred and subsequent a large amount of ROS was generated. Moreover, a NIR light was used to effectively increase the local temperature of tumor in virtue of the superior photothermal effects of MSP, which enabled us to accelerate the ROS generation and achieved an enhanced ROS yield. The newly developed nanodrug system displayed a high level of intracellular ROS generation, leading to the desired killing efficacy against malignant cells and solid tumor. This smart nanosystem holds great potential to overcome the existing barrier in PDT and opens a promising avenue for anticancer therapy.
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PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2018
·Vol. 43
·期 7
·637-641
·
IF 1.749
Naimeng Song,Jianchao Liu,Guoying Zhang,Zhenzhan Yan,Hongxu Gao,Li Yang
This paper describes the preparation of two combustion catalysts Tannin-Fe (Ta−Fe) and Phloroglucinol-Fe (Ph−Fe) by spray drying. The particle size and morphology of the particles are observed by scanning electron microscopy (SEM). The results of SEM image show that the particles are regular spherical and very good dispersion. The diameter of most spherical particles is about 1 μm. The effects of Ta−Fe and Ph−Fe on the thermal decomposition of RDX and AP were tested by differential scanning calorimeter (DSC). DSC dates show that Ta−Fe and Ph−Fe can advance the high temperature exothermic peak of AP 18.0 °C and 16.1 °C, respectively. The burning rates illustrates that both Ta−Fe and Ph−Fe can significantly increase the combustion rate of HTPB propellants. The formulation with 2 mass% Ta−Fe shows an average 21.31 % increase in burning rate and has a low value of the exponent n=0.48. The formulation with 2 mass%Ph−Fe has a burning rate 20 to 60 % larger than that of the initial AP/HTPB/Al formulation, and has a lowest exponent n=0.45.
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CATALYSIS TODAY
·
2018
·
IF 4.667
Luyao Ren,Liangzhong Li,Shuai Chen,Hui Li,Yongdi Liu,Liyang Zhou,Su Guo,YunJiang Yu
In this study, Fe/FeS@SiO 2 yolk-shell particles (Fe/FeS@SiO 2 YSPs) were synthesized, characterized, and applied to tetrabromobisphenol A (TBBPA) removal in simulated groundwater. The X-ray photoelectron spectroscopy, X-ray diffraction, Scanning electron microscopy, transmission electron microscopy and Brunauer Emmett Teller results revealed that Fe/FeS@SiO 2 YSPs possess special structures, including active cores, mesoporous networks, shells, hollow cavities and a large surface area (85 m 2 /g vs. 8 m 2 /g) compared to Fe/FeS. The mobility of the synthesized particles in porous media was simulated with sand column experiments. Fe/FeS@SiO 2 YSPs showed a much better transportability (83.02% of particles successfully transported through the column) than Fe/FeS particles (only 1.68%), related to the better suspension stability and much lower particle surface charge (−22.7 mV vs. −7.6 mV) at neutral pH. Improved TBBPA reduction performance in synthetic solution was observed for Fe/FeS@SiO 2 YSPs over bare Fe/FeS. The transformation pathway of TBBPA was studied in detail, revealing the formation of tri-BBPA, di-BBPA, mono-BBPA and BPA as the main products. In brief, thanks to the hollow mesoporous silica spheres (HMSS) coated on the surface of Fe/FeS particles, Fe/FeS@SiO 2 YSPs showed an enhanced dispersibility, transportability and degradation of TBBPA in simulated groundwater. The results in this study proved that Fe/FeS@SiO 2 YSPs are a promising material for in situ remediation of TBBPA in soil and groundwater.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
·
IF 2.829
Yanjun Liu,Ping Na,Jitao Chen,Yulong Xie
K 2 Zn 3 [Fe(CN) 6 ] 2 @ Ni-P (KNiP) composites with high cesium selectivity were synthesized for the first time. Nickel phosphorus (NiP) was used as a solid base for the adsorption of K 2 Zn 3 [Fe(CN) 6 ] 2 (KZnHCF). The synthesized KNiP composites were characterized by SEM, TEM, XRD , VSM and BET. The characteristic results demonstrated that the composites possess a ball-shape structure, a large surface area of 305.031 m 2 /g and high saturation magnetization of 2.95 emu/g. The ICP-OES analyser was used to determine the concentration of ions in this study. KNiP showed good cesium adsorption performance over a wide pH range and high selectivity for cesium over coexistent competing ions. Analysis of dynamics showed that KNiP has good adsorption performance toward cesium, with an adsorption capacity of 54.95 mg/g. Equilibrium was achieved within only two hours and the experimental data fit the Pseudo second-order model, indicating that the adsorption process was chemisorption . The adsorption process followed the Freundlich isotherm model, indicating that it mainly occured on a heterogeneous surface.
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APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Junjie Pan,Xin Sun,Tao Wang,Zetao Zhu,Yuping He,Wei Xia,Jianping He
Magnetic metallic materials compounded with dielectric loss materials are promising for efficient microwave absorption as a result of the synergistic effect between dielectric loss and magnetic loss, as well as the optimized impedance matching. In this paper, porous coin-like structured Fe@MoS 2 composite has been fabricated via solvothermal method accompanied by subsequent heat treatment under H 2 /Ar atmosphere. The structure and morphology of as-prepared Fe@MoS 2 composite indicates that MoS 2 nanosheets with the two-dimensional (2D) structure are well dispersed on the porous coin-like Fe micro-sheets to form a core-shell structure. Particularly, the addition of MoS 2 regulates the permittivity as well as improves the impedance matching of the Fe@MoS 2 composite. The as-prepared composite shows efficient microwave absorption properties with the maximum effective absorption bandwidth (reflection loss below −10 dB) of about 4.73 GHz (11.13–15.86 GHz) at the corresponding coating thickness of 2.0 mm, accompanied by the minimum reflection loss of about −37.02 dB. When the calcination temperature increases to 650 °C, the effective microwave absorption frequency band shifts to the lower frequency (9.91–14.19 GHz) with the minimum reflection loss of about −35.5 dB under the coating thickness of 2.0 mm. Considering the efficient microwave attenuation, the as-fabricated porous coin-like Fe@MoS 2 composite can be a hopeful candidate in the field of microwave absorption.
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Polymers
·
2018
·Vol. 10
·期 9
·934
·
IF 2.935
Guangqian Zhu,Xianhui Zhang,Mengmeng Zhao,Liang Wang,Chuyang Jing,Peng Wang,Xiaowu Wang,Qinggang Wang
A series of iminopyridine complexes of Fe(II) and Co(II) complexes bearing fluorinated aryl substituents were synthesized for the polymerization of isoprene. The structures of complexes3a,2band3bwere determined by X-ray diffraction analysis. Complex3acontained two iminopyridine ligands coordinated to the iron metal center forming an octahedral geometry, whereas2badopted a chloro-bridged dimer, and3bfeatured with two patterns of cobalt centers bridged via chlorine atoms. Complexes2band3brepresented rare examples of chlorine bridged bimetallic Co(II) complexes. The fluorine substituents effects, particularly on catalytic activity and polymer properties such as molecular weight and regio-/stereo-selectivity were investigated when these complexes were employed for isoprene polymerization. Among the Fe(II)/methylaluminoxane (MAO) systems, the 4-CF3substituted iminopyridine Fe(II) complex1awas found as a highly active isoprene polymerization catalyst exhibiting the highest activity of 106g·(mol of Fe)−1·h−1. The resultant polymer displayed lower molecular weight (Mn= 3.5 × 104g/mol) and moderate polydispersity index (PDI = 2.1). Furthermore, the ratio ofcis-1,4-/3,4 was not affected by the F substituents. In the series of Co(II)/AlEt2Cl binary systems, complexes containing electron-withdrawing N-aryl substituents (R = 4-CF3, 2,6-2F) afforded higher molecular weights polyisoprene than that was obtained by the complex containing electron-donating N-alkyl substituents (R = octyl). However, ternary components system, complex/MAO/[Ph3C][B(C6F5)4] resulted in low molecular weight polyisoprene (Mn< 2000) with hightrans-1,4-unit (>95%).Keywords:iminopyridine ligands;Fe(II);Co(II) complexes;isoprene polymerization;fluorinated aryl substituents
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JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2018
·Vol. 51
·期 29
·295107
·
IF 2.373
Jun Zhang,Jun Liao,Lexi Shao,Shuwen Xue,Zhiguo Wang
High quality micron-sized Cu2FexZn1−xSnS4 single crystals have been successfully fabricated by flux growth method using CuS, FeS, ZnS and SnS as the raw materials and CsCl as the fluxing agent. The effects of Fe contents on the morphology, structure and optical properties of Cu2FexZn1−xSnS4 single crystals were investigated. X-ray diffraction and Raman analyses reveal that the kesterite and stannite phases coexist in the Cu2FexZn1−xSnS4 crystals, and peak splittings of (2 0 4) and (3 1 2) are observed for the sample with x = 0.2. The optical absorption spectra reveal that the optical bandgap of the single crystal samples has little dependence on the Fe content due to the coexistence of the kesterite and stannite phases. The bandgap of the Cu2FexZn1−xSnS4 single crystal generally locates between 1.672 and 1.716 eV. Though the bandgap is not ideal as the absorber for single-junction solar cells according to the S–Q limit, it is an ideal material for the top cell in tandem solar cells and solar-driven water splitting.
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危险品化学品经营许可证（带存储）