Catalysis Science & Technology
·
2019
·Vol. 9
·期 21
·6015-6026
·
IF 5.726
Wen Tang,Tonghao Ma,Lina Zhou,Gaoya Wang,Xiaoli Wang,Hanjie Ying,Chao Chen,Ping Wang
Tannic acid (TA) is a natural polyphenol that has been widely modified on various supporting materials for enzyme immobilization; however, the time-consuming formation of the TA layer and its poor mechanical stability on substrates seriously hinder the practical applications of TA. Herein, we report a facile, rapid and stable enzyme immobilization strategy based on polyamine-induced tannic acid co-deposition on magnetic nanoparticles. Specifically, a tannic acid/polyamine binary system was first deposited and polymerized on the surface of magnetic nanoparticles through a modified mussel-inspired method, and then, an enzyme was immobilized on the formed polymer layer via a spontaneous Schiff-base reaction. The study on the physical properties revealed that polyamine as an intramolecular cross-linker could significantly accelerate the deposition of TA on supports and stabilize the structure of the formed polymer layer. Moreover, CALB, as a representative lipase for biodiesel production, was successfully immobilized on this nanocomposite with a 132.8 mg g−1 support loading capacity and 56.7% activity recovery under optimal conditions. Furthermore, the physicochemical properties of immobilized CALB displayed many significant advantages, including improved pH stability, temperature and methanol tolerance, as compared to those of free CALB. In particular, the theoretical simulation and structural analysis of immobilized CALB demonstrated that this nanocomposite could effectively prevent structural damage to the active pocket of CALB. Moreover, the immobilized CALB exhibited high production efficiency and reusability for further application in the production of biodiesel as compared to free CALB. Interestingly, the immobilized CALB showed very efficient catalytic properties under an alternating magnetic field than the control without an alternating magnetic field, and the reaction rate was enhanced with an increase in magnetic field frequency and strength. Therefore, this polyamine-induced TA co-deposition and polymerization strategy may provide an improved nanoplatform for enzyme immobilization.
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高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 5
·2483-2503
·
IF 2.014
Mao Hui,Wang Weiji,Ma Yongle,Huang Yan
An anionic polymer P (ANAN) of acrylamide, N -vinyl-2-pyrrolidone and 2-acrylamide-2-methylpropanesulfonic acid was synthesized through free radical polymerization and initiated by 2,2′-Azobis (2-methylpropionamide) dihydrochloride as an anti-high temperature and anti-calcium and magnesium contamination fluid loss control additive for water-based drilling fluid. The P (ANAN) was characterized by 13 C-NMR and 1 H-NMR, FTIR, elemental analysis and GPC analysis. The fluid loss tests were carried on different WBDFs. The results showed that this polymer can resist 4.5 × 10 5 ppm of Cl −1 , 4 × 10 5 ppm of Ca 2+ contamination at low pH environment caused by acid gas invasion in drilling fluid at 180 °C. The fluid loss control mechanisms of P (ANAN) were investigated by Zeta potential analysis, particle size distribution analysis and mud cake quality analysis. The thermal stability was investigated by TGA analysis. The results illustrate that the P (ANAN) exhibits a stronger interaction with clays and higher-temperature resistance, and it can improve the colloidal dispersion property obviously for drilling fluid under salts, calcium and magnesium contamination and even under circumstances of acid gas invasion conditions. Due to its superior fluid loss control properties, the P (ANAN) can be a promising polymer for water-based drilling fluid in deep and ultra-deep well drilling applications.
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DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 15
·5035-5047
·
IF 4.052
Ling Zhu,Yue-Ling Bai,Yongmei Zhao,Feifei Xing,Ming-Xing Li,Shourong Zhu
A complexone analog chemosensor, H2L, bearing chelating bis(2-pyridylmethyl) amine and alizarin groups was synthesized via the Mannich reaction. H2L chromically responds to OH−, F−, CH3COO−, and H2PO4− in DMF, CH3CN, and acetone, but not in CH3OH or H2O. The addition of F− ions to H2L selectively induces a significant and visible color change in acetonitrile and shifts both methylene proton signals upfield. H2L also exhibits visible responses to Mg2+, Sr2+, Ba2+, Tb3+, Cu2+, Co2+, Ni2+, Zn2+, Mn2+, Cd2+, and Fe3+ in solution. AlCl3 can form an Al : L = 2 : 3 complex that not only changes the color of the DMF solution, but also significantly increases its fluorescence intensity. The limit of fluorescence turn-on detection for AlCl3 in DMF is 2.7 × 10−8 M, which is an order higher than those of other anthraquinone sensors reported in the literature. NMR spectroscopy shows that hydroxyl is not deprotonated upon interacting with Al3+, but will be partially deprotonated in the presence of Zn2+. Contrary to the complexone, the H2L–Ce(III) complex does not react chromically to F−. However, the H2L–NiCl2 complex responds chromically to F−, with higher sensitivity (LOD = 1.3 × 10−6 M F− in acetonitrile) than free H2L. The spectral changes in the presence of F− are similar to that of OH−; however, the spectrum shifts slightly to a longer wavelength and is more sensitive to both H2L and the H2L–NiCl2 complex. Moreover, 4% or less H2O in the solvent essentially has no influence on the F− sensitivity; however, high water content significantly decreases the F− sensitivity. The spectral changes of the Zn2+, Cu2+, Fe3+, Ce3+, and Ni2+ complexes in the presence of different NaOH concentrations were also investigated.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2020
·Vol. 31
·期 3
·2005092
·
IF 16.836
Yang Yang,Jinfei Xiao,Jinyan Cai,Gongming Wang,Wencheng Du,Yufei Zhang,Xihong Lu,Cheng Chao Li
Environment-friendly and low-cost aqueous zinc-ion batteries (ZIBs) have received considerable attention for large-scale energy storage. However, the low coulombic efficiency and potential safety hazards of Zn-metal anodes severely hinder their practical implementations. Herein, for the first time, mixed-valence Cu 2− x Se is proposed as a new intercalation anode to construct Zn-metal-free rocking-chair ZIBs with a long lifespan. It is found that the introduction of low-valence Cu not only modify active sites for Zn 2+ ion storage, but also optimizes the electronic interaction between the active sites and the intercalated Zn 2+ ion, leading to a favorable intercalation formation energy (−0.68 eV) and reduced diffusion barrier, as demonstrated by first-principles calculation. Ex situ X-ray diffraction, ex situ transmission electron microscopy and galvanostatic intermittent titration technique measurements reveal the reversible insertion/extraction of Zn 2+ in Cu 2− x Se via an intercalation reaction mechanism. Owing to the rigid host structure and facile Zn 2+ diffusion kinetics, the Cu 2− x Se nanorod anode shows an enhanced coulombic efficiency (above 99.5%), outstanding rate capability and excellent cycling stability. The as-fabricated Zn x MnO 2 ||Cu 2− x Se Zn-ion full battery exhibits an impressive electrochemical performance, particularly an ultralong cycle life of over 20 000 cycles at 2 A g −1 . This study is expected to provide new opportunities for developing high-performance rechargeable aqueous ZIBs.
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高影响因子
NUCLEIC ACIDS RESEARCH
·
2020
·Vol. 48
·期 19
·10768-10784
·
IF 11.502
Sun Ge,Wang Chunyu,Wang Shengli,Sun Hongmiao,Zeng Kai,Zou Renlong,Lin Lin,Liu Wei,Sun Ning,Song Huijuan,Liu Wensu,Zhou Tingting,Jin Feng,Shan Zhongyan,Zhao Yue
Estrogen receptor alpha (ERα) signaling pathway is essential for ERα-positive breast cancer progression and endocrine therapy resistance. Bromodomain PHD Finger Transcription Factor (BPTF) associated protein of 18kDa (BAP18) has been recognized as a crucial H3K4me3 reader. However, the whole genomic occupation of BAP18 and its biological function in breast cancer is still elusive. Here, we found that higher expression of BAP18 in ERα-positive breast cancer is positively correlated with poor prognosis. ChIP-seq analysis further demonstrated that the half estrogen response elements (EREs) and the CCCTC binding factor (CTCF) binding sites are the significant enrichment sites found in estrogen-induced BAP18 binding sites. Also, we provide the evidence to demonstrate that BAP18 as a novel co-activator of ERα is required for the recruitment of COMPASS-like core subunits to the cis-regulatory element of ERα target genes in breast cancer cells. BAP18 is recruited to the promoter regions of estrogen-induced genes, accompanied with the enrichment of the lysine 4-trimethylated histone H3 tail (H3K4me3) in the presence of E2. Furthermore, BAP18 promotes cell growth and associates the sensitivity of antiestrogen in ERα-positive breast cancer. Our data suggest that BAP18 facilitates the association between ERα and COMPASS-like core subunits, which might be an essential epigenetic therapeutic target for breast cancer.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 4
·046524
·
IF 4.386
Binshuai Li,Xinran Liu,Mengai Yin,Lan Xue,Lina Lu,Fuju Dai,Wei Feng,Shengnan Yang,Jun Jiao,Qiang Chen
Chicoric acid (CA), a phenolic acid from chicory, is regarded as a powerful ingredient against oxidative stress and obesity. It's believed to be a promising drug candidate as its healing features prevent memory loss. However, existent methods for CA detection limit its practical applications in purification and further pharmacological study due to lack of accuracy. Therefore, it is crucial to find a forceful approach to precisely analyze cichoric acid for anti-AD research. In this work, we reported a facile method to synthesize Setaria-like trimetallic nanodendrites (G-PP NDs) in a non-compacted core–shell shape with high electrocatalytic activity. In addition, a sensitive biosensor to detect cichoric acid rapidly and accurately has been developed based on G-PP NDs and aminated reduced graphene oxide flakes (NH2-RGO@G-PP NDs). Owing to the great conductivity of NH2-RGO and significant electrochemical performance of G-PP NDs, the obtained sensor exhibited admirable capacities with a low LOD of 0.038 μM. It displayed a high sensitivity, rapid response, and excellent long-term stability, which made it accomplish the measurements CA in chicory samples. The proposed sensor is an auspicious tool for quality control and analysis of metabolism to investigate the beneficial impacts of CA as a functional ingredient to combat AD.
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2021
·
IF 3.935
Jinsheng Lin,Feifei Chen,Chaohua Bao,Jian Ma,Dan Li,Lewei Zheng,Wenquan Zhu,Wenbin Chen,Xiaoming Liu
During the related substances testing method development for linagliptin tablet, an unknown peak was observed in HPLC chromatograms with a level exceeding the identification threshold. By using a strategy that combines LC-PDA/UV-MS n with mechanism-based stress studies, the unknown peak was rapidly identified as linagliptin urea, a solution degradant that is caused by the reaction between the API and hydrocyanic acid with sonication treatment to accelerate dissolution of the drug substance in sample preparation of linagliptin tablets, and hydrocyanic acid is a known impurity in HPLC grade acetonitrile and acetonitrile is used as part of diluent. The mechanism of the solution degradation chemistry was verified by stressing linagliptin API with trimethylsilyl cyanide (TMSCN, which can give off HCN slowly in the presence of water) treated with sonication in the sample preparation. Further investigation found that when the sonication treatment was replaced by vortex vibration in the process of the sample preparation, the RRT 1.28 species was decreased to below the level of the detection limit (0.02%). The structure of this impurity was further confirmed through the synthesis of the impurity and subsequent structure characterization by 1D and 2D NMR . Due to the presence of trace amount of HCN in HPLC grade acetonitrile, these types of solution degradation would likely occur in analysis of pharmaceutical finished products containing APIs with primary and secondary amine moieties drug product during sample preparations, particularly when sonication treatment is used to accelerate dissolution of drug substance from the finished drug product. In the GMP quality control laboratories, such events may trigger undesirable out-of-specification (OOS) events. Hence, the results of this paper can help to prevent these events from happening in the first place or resolve these OOS events in GMP laboratories.
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高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2020
·Vol. 305
·期 4
·1900835
·
IF 3.853
Yi Yang,Ling-yan Li,Bo Yin,Ming-bo Yang
Conductive composites based on polymers and conductive nanofillers are widely studied as a promising material. The rational design of 3D conductive networks in composites is crucial to improve their electrical conductivity and reduce the dosage of nanofillers. Herein, poly(vinylidene fluoride) (PVDF) and polystyrene (PS) bi-continuous structures with modified carbon nanotubes (CNTs) tailored to anchor at the interface are designed to achieve an ultralow electrical percolation threshold because of the formation of a thin interfacial conductive layer. In this work, the modification of CNTs with poly(methyl methacrylate) (PMMA), which contributes to the improvement of the compatibility between PVDF and CNTs, is effective to control the distribution of CNTs in composites. It promotes the migration of CNTs from the PS phase to the interface of PVDF and PS. Consequently, the interfacial conductive layer is formed at a low CNT content, and the electrical percolation threshold of PVDF/PS/CNTs-PMMA nanocomposites is only 0.07 vol%, having a great decrease of about 50% compared with that of PVDF/PS/CNTs nanocomposites. Thus, it is demonstrated that the distribution of CNTs can be tailored to anchor at the interface by proper chemical modification to form an interfacial conductive layer and a decrease of percolation threshold can also be achieved.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Xueping Huang,Aiping Wang,Jian Luo,Yue Gao,Lei Guan,Peng Zhang,Feng Liu,Wei Mu,Beixing Li
Recently, size-controlled pesticide microcapsule (MC) delivery systems have played an important role in precision farming development; however, the potential environmental hazards of MCs with different particle sizes have not been fully characterized. In this study, we prepared a series of lambda-cyhalothrin (LC)-MCs with nano and micron-scale capsule sizes (average diameters of 209.4 nm, MC-N; 2.41 µm, MC-S; 4.87 µm, MC-M; and 12.41 µm, MC-L). The assessment results showed that the release and sedimentation behavior of LC-MCs in water and toxicity to zebrafish at three life stages were all particle size-dependent. As the diameter distribution of approximately 100 nm extended to the micron scale (~27 µm), the capsules released more slowly and sunk more quickly in water. In addition, micron-sized LC-MC exposure resulted in significantly less fish mortality and malformations of larvae and embryos compared with nanosized LC-MC exposure. The highest accumulation of MC-N in the gill and the severest toxicity to larvae suggested that the smaller size and stronger permeability of nanocapsules would pose unpredictable consequences for nontargeted organisms. The obvious toxicological differences of LC-MCs toward aquatic organisms implies that regulating MC production in an appropriate size range is an important prerequisite for achieving efficient but safe pesticide applications .
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Yan Sun,Yinlong Zhou,Yaping Zhu,Yuhua Shen,Anjian Xie
The design and synthesis of a heterostructure as well as binder-free electrodes or electrocatalysts with a porous nanostructure for enhancing electrochemical performance of lithium ion batteries and water splitting are still significant challenges to scientists. Here, for the first time, an in-situ synthesis of the porous petal-like MoN nanolayer-coated MoO2 heterojunction (MoO2@MoN) on commercial nickel foam (NF) by a localized nitrided transformation method as both a binder-free electrode for LIBs and an electrocatalyst for water splitting was performed. The in-situ formation of the MoN nanolayer could create a MoO2@MoN heterostructure, therefore enhancing the electronic conductivity and the electron/ion transfer. The XRD and XPS measurements confirmed the wonderful reversibility of the MoN layer during lithiation/delithiation cycling, which effectively promoted the long-life cycling performance (1190.1 mA h g–1 after 500 cycles at the current density of 0.5 A g–1). Meanwhile, the MoO2@MoN/NF/LiFePO4 full cell displayed stable capacity after 100 cycles. Moreover, the product also showed the improved electrocatalytic activity for hydrogen evolution and oxygen evolution. The excellent results suggest that our work opens a simple in-situ heterojunction formation pathway for the synthesis of other multifunctional materials applied in energy conversion and storage.
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高影响因子
ANALYST
·
2014
·Vol. 139
·期 22
·5858-5867
·
IF 3.906
Yizhong Shen,Shaopu Liu,Ling Kong,Xuanping Tan,Youqiu He,Jidong Yang
Although various strategies have been reported for double-stranded DNA (DNA) detection, development of a time-saving, specific, and regeneratable fluorescence sensing platform still remains a desired goal. In this study, we proposed a new DNA detection method that relies on an “off-on” switch of a regenerated fluorescence biosensor based on an electron transfer mechanism from glutathione (GSH)-capped CdTe quantum dots (QDs) to nile blue (NB). Initially, the high fluorescence of GSH-capped CdTe QDs could be effectively quenched by NB due to the binding of NB to the GSH on the surface of the QDs and the electron transfer from the photoexcited GSH-capped CdTe QDs to NB. Then, the high affinity of DNA to NB enabled the NB to be dissociated from the surface of GSH-capped CdTe QDs to form a more stable complex with DNA and suppress the electron transfer process between GSH-capped CdTe QDs and NB, thereby restoring the fluorescence of NB surface modified GSH-capped CdTe QDs (QDs–NB). In addition, we have testified the regenerability of the proposed DNA senor. The corresponding result shows that this DNA sensor is stable for two reuses. This fluorescence “off-on” signal was sensitive to the concentration of DNA in the range from 0.0092 to 25.0 μg mL−1 with a good correlation coefficient of 0.9989, and the detection limit (3σ/S) was 2.78 ng mL−1. To further investigate for perfect analysis performance, the developed biosensor was applied for the determination of DNA in human fresh serum samples with satisfactory results.
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高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 6
·1831-1837
·
IF 4.831
Yang Zhen,Liu Yan,Lei Chong,Sun Xue-cheng,Zhou Yong
We report on a method for ultrasensitive detection and quantification of the pathogen Escherichia coli ( E. coli ), type O157:H7. It is using a tortuous-shaped giant magnetoimpedance (GMI) sensor in combination with an open-surface microfluidic system coated with a gold film for performing the sandwich immunobinding on its surface. Streptavidin-coated super magnetic Dynabeads were loaded with biotinylated polyclonal antibody to capture E. coli O157:H7. The E. coli -loaded Dynabeads are then injected into the microfluidics system where it comes into contact with the surface of gold nanofilm carrying the monoclonal antibody to form the immunocomplex. As a result, the GMI ratio is strongly reduced at high frequencies if E. coli O157:H7 is present. The sensor has a linear response in the 50 to 500 cfu·mL −1 concentration range, and the detection limit is 50 cfu·mL −1 at a working frequency of 2.2 MHz. In our perception, this method provides a valuable tool for developing GMI-based microfluidic sensors systems for ultrasensitive and quantitative analysis of pathogenic bacteria. The method may also be extended to other sensing applications by employing respective immunoreagents.
Fig. (a) Graphical illustration of the test setup. (b) Relationship of GMI signal vs. E. coli O157:H7 concentration.
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