Catalysis Science & Technology
·
2015
·Vol. 5
·期 6
·3194-3202
·
IF 5.426
Nan Mei,Bing Liu,Judun Zheng,Kangle Lv,Dingguo Tang,Zehui Zhang
In this study, magnetically separable, graphene oxide-supported palladium nanoparticles (C–Fe3O4–Pd) were successfully prepared via a one-step solvothermal route. The C–Fe3O4–Pd catalyst showed excellent catalytic performance in the aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA). The base concentration and reaction temperature significantly affected both HMF conversion and FDCA selectivity. High HMF conversion (98.2%) and FDCA yield (91.8%) were obtained after 4 h at 80 °C with a K2CO3/HMF molar ratio of 0.5. The C–Fe3O4–Pd catalyst was easily collected by an external magnet and reused without significant loss of its catalytic activity. The developed method is a green and sustainable process for the production of valuable FDCA from renewable, bio-based HMF in terms of the use of water as solvent, the use of stoichiometric amount of base, high catalytic activity under atmospheric oxygen pressure, and facile recyclability of the catalyst.
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DESALINATION
·
2012
·
IF 2.59
Ying Xu,Ben Zhang,Linlin Zhao,Yuanchen Cui
Polyaspartic acid/5-aminoorotic acid graft copolymer (PASP/5-AOA) was synthesized by the reaction of maleic anhydride , urea and 5-aminoorotic acid (5-AOA). The graft copolymer (PASP/5-AOA) was characterized by FT-IR and UV–VIS analyses. Its performance was evaluated by static scale inhibition method and dynamic corrosion testing . The results showed that PASP/5-AOA possessed super scale inhibition property against CaCO 3 and Ca 3 (PO 4 ) 2 as well as good corrosion inhibition property. Inhibition efficiency of PASP/5-AOA was close to 100% against CaCO 3 when the dosage was 1 mg/L in the simulation experiment. Corrosion inhibition efficiency was close to 60% and scale inhibition efficiency was close to 100% against Ca 3 (PO 4 ) 2 when the dosage was 12 mg/L in the simulation experiment. When PASP/5-AOA was added to the solution, CaCO 3 and Ca 3 (PO 4 ) 2 deposits show flower and cascade patterns with floppy accumulation by scanning electron microscopy (SEM).
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Energy Technology
·
2015
·Vol. 4
·期 5
·600-609
·
IF 2.824
Yating Shen,Yunlei Zhang,Yao Chen,Yongsheng Yan,Jianming Pan,Meng Liu,Weidong Shi
Stable oil-in-water high internal phase emulsions (HIPEs) with an internal phase volume fraction of 85 % were stabilized using Tween 85. The prepared poly(HIPEs) were first investigated as adsorbents to treat water polluted with Cr III , and then the catalysts with Lewis acidic sites was synthesized. The catalysts with Brønsted acidic sites were obtained by ion-exchanging. The as-prepared HIPEs–Cr III (PEs–Cr III ) and HIPEs–SO 3 H (PEs–SO 3 H) possess open-cell structure, interconnecting pores, and strong acidity, they are utilized as highly efficient catalysts for the conversion of biomass to 5-hydroxymethylfurfural (HMF). These results showed maximum production yields for cellulose, glucose, and fructose of 37.0 %, 58.0 %, and 80.8 %, respectively. PEs–Cr III and PEs–SO 3 H can be very easily recycled at least four times without significant loss of activity. Herein, a new method is presented to transform cellulose by using two catalysts in a one-pot process for meeting the varying demands involved at different reaction stages.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2015
·
IF 2.729
Xiaolan Zeng,Xuesheng Zhang,Li Qin,Zunyao Wang
The tissue distribution, excretion, and metabolic pathway of 2,2′,4,4′,5-penta-chlorinated diphenylsulfide (CDPS-99) in ICR mice were investigated after oral perfusion at 10 mg/kg body weight (b.w.). Biological samples were extracted and separated and, for the first time, were determined by a novel, sensitive, and specific GC–MS method under the full scan and selected ion monitoring (SIM) modes. The results showed that the concentrations of CDPS-99 in the liver, kidneys, and serum reached a maximum after a one-day exposure and that the CDPS-99 concentration in the liver was the highest (3.43 μg/g). The increase in the concentration of CDPS-99 in muscle, skin, and adipose tissue was slower, and the concentrations of CDPS-99 achieved their highest levels after 3 days of exposure. It was observed that the CDPS-99 concentration in adipose tissue was still very high (0.71 μg/g) after 21 days of exposure, which suggested that CDPS-99 was able to accumulate in adipose tissue. In addition, mouse feces accounted for approximately 75% of the total gavage dose, indicating that CDPS-99 was mainly excreted via mouse feces. Metabolism analysis demonstrated that there were three possible metabolic pathways of CDPS-99 in mice: dechlorination reactions with the formation of tetra-CDPS and hydroxylation and oxidation reactions with the formation of OH-CDPS-99 and chlorinated diphenylsulfone. The present study will help to develop a better understanding of mammalian metabolism of CDPS-99.
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PubMed
高影响因子
ELECTROANALYSIS
·
2013
·Vol. 25
·期 7
·1697-1705
·
IF 2.817
Xiaoxia Zheng,Lishi Wang
Direct electrocatalytic oxidation and simultaneous determination of 5-methylcytosine (5-mC) and cytosine(C) were realized in alkaline solutions by differential pulse voltammetry (DPV) based on an electrochemically reduced graphene oxide (er-GO) modified glassy carbon electrode (er-GO/GCE). The as-prepared er-GO/GCE exhibited good electrocatalytic activity towards the oxidation of 5-mC and C. Under optimum conditions, the er-GO/GCE was applied to the simultaneous determination of 5-mC and C with a significantly improved peak potential resolution (about 150 mV), and a linear relationship can be obtained in the range of 6–200.0 µmol/L and 8–250.0 µmol/L, respectively. In addition, the proposed method was further successfully applied to the analysis of methylation status in short CpG oligonucleotides with satisfactory results.
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CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Bo Yuan,Jin Guan,Jun Peng,Guang-zhou Zhu,Ji-hong Jiang
Ionic liquids (ILs) with catalysts have been widely investigated in the production of 5-hydroxymethylfurfural (5-HMF) from biomass, in particular those which are high in cellulose. In this study, a series of hydrophobic imidazolium ionic liquids and magnetic-chitosan metallo-porphyrin particles (MCMP-M) were designed and their abilities to convert 5-hydroxymethylfurfural (5-HMF) and total reducing sugars (TRS) from the corncob were evaluated. The results showed that [moMIM][PF 6 ] and MCMP-Al were suitable solvents and both the catalysts were effective for the 5-HMF and TRS conversion (52.47 and 31.06, respectively). The mixed catalysts (MCMP-Al, Cr and Mg) coupled with [moMIM][PF 6 ] could increase the conversion yield of 5-HMF and TRS (66.58% and 43.68% in 50 min, respectively) with infrared radiation heating during distillation under reduced pressure for a short time (50 min). More importantly, the products could be separately recovered through the aqueous phase and the ILs and catalysts could be reused up to 40 times despite the slight loss of its catalytic activity. Moreover, the catalyst system also could be used for other carbon sources to produce the 5-HMF.
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JOURNAL OF CELLULAR BIOCHEMISTRY
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2017
·Vol. 119
·期 2
·1501-1510
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IF 3.085
Qing Wang,Pu Wang,Hong Zhou,Yan Hu,Chengshen Xie,Fei Gao,Ningjie Ma,Haoli Hou,Hao Zhang,Lijia Li
DNA methylation plays a crucial role in lots of biological processes and cancer. 5-azacytidine (5-AC), a DNA methylation inhibitor, has been used as a potential chemotherapeutic agent for cancer. In this study, we used 5-AC treatment to investigate whether DNA methylation was involved in regulation of programmed cell death (PCD) in mouse embryo fibroblast NIH-3T3 cells which could undergo PCD after treatment with TNF-α and cycloheximide (CHX). The results showed that the genomic DNA of NIH-3T3 cells was hypermethylated during PCD induced by TNF-α and CHX, and 5-AC might prevent this PCD process. However, treatment with the other three DNA methylation inhibitors, 5-aza-deoxycytidine, 6-thioguanine and RG108, did not interfere with the NIH-3T3 cell PCD process. Additionally, knockdown of DNMT1 did not affect the apoptosis process. The present results and observations indicated that 5-AC specifically inhibited the NIH-3T3 apoptosis process via a genomic DNA methylation-independent pathway. During the TNF-α and CHX-inducing apoptosis process, the PCD related BCL-2 family proteins were significantly down-regulated. Furthermore, after the small interference RNA-mediated knockdown of BCL-XL, one of the BCL-2 family proteins, 5-AC did not inhibit the apoptosis process, suggesting that 5-AC inhibited the PCD process induced by TNF-α and CHX by affecting the anti-apoptotic protein BCL-XL.
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高影响因子
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Jie-Qiong Chen,Shi-Fan Xue,Zi-Han Chen,Shengqiang Zhang,Guoyue Shi,Min Zhang
A novel label-free ratiometric fluorescent probe is developed for the detection of H 2 O 2 based on GelRed/[G 3 T] 5 /Tb 3+ hybrid, in which GelRed (a nucleic acid dye) intercalated into the designed single-stranded DNA [G 3 T] 5 (i.e. GelRed/[G 3 T] 5 ) acts as a stable build-in reference with red emission and Tb 3+ sensitized by [G 3 T] 5 (i.e. [G 3 T] 5 /Tb 3+ ) as a sensitive response signal with green fluorescence. With the successive addition of Hg 2+ and cysteine (Cys) to GelRed/[G 3 T] 5 /Tb 3+ , the fluorescence of [G 3 T] 5 /Tb 3+ can be effectively quenched and recovered respectively, while the fluorescence of GelRed/[G 3 T] 5 remains unchangeable. Combined with these properties, we have demonstrated its application for label-free ratiometric fluorescence detection of H 2 O 2 with self-calibration. The sensing mechanism is based on the specific reaction between H 2 O 2 and Cys, the resulting disulfide reverses the Cys-mediated fluorescence changes of [G 3 T] 5 /Tb 3+ . This method is further applied to the monitoring of oxidase-related reactions. As the glucose oxidase (GOx)-biocatalyzed oxidation of glucose and the acetylcholine esterase/choline oxidase (AChE/ChOx) cascade yield H 2 O 2 , such two biocatalytic processes are successfully examined utilized our proposed method, indicating its potential broad applications in biomedical analysis. In addition, we have also demonstrated its feasibility for oxidase-based visual biosensing, in which only a handheld UV lamp is used. Importantly, coupled with our proposed visual biosensing, a realtime quantitative scanometric assays has been also demonstrated by using a smartphone with easy-to-access color-scanning APP as the detection platform. Compared to traditional methods, the proposed design is cost-effective, simple to prepare and easy-to-use without fluorescence labeling or chemical modification.
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Analytical Methods
·
2016
·Vol. 8
·期 10
·2290-2296
·
IF 1.915
Yonggui Song,Couchong Gong,Dan Su,Yuan Shen,Yonghai Song,Li Wang
In this work, the spherical porous MOF-5 microstructures supported by three-dimensional (3D) kenaf stem-derived porous carbon (KSC) (denoted as MOF-5/3D-KSC) composites were constructed for ascorbic acid (AA) sensing. The formation of MOF-5/3D-KSC was verified by scanning electron microscopy, X-ray powder diffraction and energy dispersive X-ray spectroscopy. The results showed that spherical porous MOF-5 microstructures were evenly arrayed on the surface of 3D-KSC via a simple one-step hydrothermal method, which could greatly increase the effective surface area, stability and active sites. The MOF-5/3D-KSC composites were directly used to prepare integrated MOF-5/3D-KSC electrodes for AA sensing, and the integrated electrodes showed better performance for AA detection than traditional enzyme-based sensors and nonenzymatic sensors. The sensor exhibited good stability, wide linear range (0.7 μM to 11.5 mM) and low detection limit (0.24 μM). Hence, the MOF-5/3D-KSC composites could be a potential material for sensing platforms.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2016
·
IF 3.902
Haogang Duan,Shaoyu Lü,Chunmei Gao,Xiao Bai,Hongyan Qin,Yuhui Wei,Xin’an Wu,Mingzhu Liu
In this work, thiolated chitosan/alginate composite microparticulates (CMPs) coated by Eudragit S-100 were developed for colon-specific delivery of 5-aminosalicylic acid (5-ASA) and curcumin (CUR), and the use of it as a multi drug delivery system for the treatment of colitis. The physicochemical properties of the CMPs were evaluated. In vitro release was performed in gradually pH-changing medium simulating the conditions of different parts of GIT, and the results showed that the Eudragit S-100 coating has a pH-sensitive release property, which can avoid drug being released at a pH lower than 7. An everted sac method was used to evaluate the mucoadhesion of CMPs. Ex vivo mucoadhesive tests showed CMPs have excellent mucosa adhesion for the colonic mucosa of rats. In vivo treatment effect of enteric microparticulates systems was evaluated in colitis rats. The results showed superior therapeutic efficiency of this drug delivery system for the colitis rats induced by TNBS. Therefore, the enteric microparticulates systems combined the properties of pH dependent delivery, mucoadhesive, and control release, and could be an available tool for the treatment of human inflammatory bowel disease.
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APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Jie Su,Weiyuan Yao,Yue Liu,Zhongbiao Wu
A series of HZSM-5 supported CrO x catalysts at different loadings were prepared by wet impregnation method for catalytic combustion of dichloromethane (DCM) in this paper. The catalytic activity tests indicated that both DCM conversion and product selectivity varied greatly with Cr doping contents. The sample at 2 wt% loading showed the highest DCM conversion, while the selectivity toward CO/CO 2 increased at an elevated CrO x loading. The characterization results revealed that the surface acidity and the chemical states of Cr were strongly affected by the doping content. The surface acidity would decline at an elevated Cr loading owing to the interactions between surface OH groups and chromium ions. And higher surface Cr(VI)/Cr(III) ratios could be observed on the catalysts at lower CrO x doping, leading to the improvement of reducibility. The activity and selectivity of DCM catalytic degradation were found to be highly depended on the balance of surface acidity and redox property. The increased surface acidity could result in the enhancement of dissociated adsorption of DCM, which are beneficial to the catalytic activity. However, higher surface acidity meant lower Cr loading, which might lead the adsorbed intermediates incompletely oxidized and the decrease in CO x selectivity due to the limit redox ability.
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Biomass Conversion and Biorefinery
·
2025
·
IF 4.1
Cui Yong,Wang Wenliang,Xu Xiaolu,Miao Hui,Fu Yishuai
In order to increase the yield of high-value components in bio-oil from waste wood-based panels (WWPs), a composite catalyst of SiC@HZSM-5 with both excellent capacities of microwave absorption and catalytic conversion was successfully prepared and applied to the microwave-assisted pyrolysis (MAP) with microwave power of 1000 W (2.45 GHz). The effects of different Si/Al ratios of HZSM-5 on the characterization of catalysts and selective pyrolysis products also have been investigated. The results showed that the obtained SiC@HZSM-5 catalyst exhibited a stable composite structure, favorable dielectric loss characteristics, and high thermal conductivity. Compared with the non-catalytic experiment, SiC@HZSM-5 catalysts significantly enhanced the relative content of nitrogen-containing compounds and reduced the concentration of oxygen-containing compounds in bio-oil, though there was one slight negative impact on bio-oil yield. Importantly, with the increase in Si/Al ratio from 30 to 90, the production of nitrogen-containing compounds was found to decrease from 37.11 to 23.14%, due to the reduction of acidic sites in catalysts. It was noteworthy that during the pyrolysis of WWPs by microwave heating, the catalyst with the Si/Al ratio of 30 significantly promoted the interactions between lignocellulosic components and adhesives and improved the selectivity of amide-N compounds (14.06%, acetamide being the main products) and heterocyclic-N compounds (23.05%, pyrroles, pyridines, and pyrazines constituted the major composition). This work could offer a promising technical reference to thermally converted WWPs to high value-added chemicals by microwave-assisted catalytic pyrolysis (MACP).
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