ENZYME AND MICROBIAL TECHNOLOGY
·
2023
·
IF 3.4
Shuangshuang Duan,Yonghua Chen,Guodong Wang,Zebin Li,Shitong Dong,Yingshuai Wu,Yuanwei Wang,Chunling Ma,Ruiming Wang
D -Allose is a rare cis-caprose with a wide range of physiological functions, which has a wide range of applications in medicine, food, and other industries. L -Rhamnose isomerase ( L -Rhi) is the earliest enzyme found to catalyze the production of D -allose from D -psicose. This catalyst has a high conversion rate, but its specificity for substrates is limited; thus, it cannot fulfill the requirements of industrial production of D -allose. In this study, L -Rhi derived from Bacillus subtilis was employed as the research subject, and D -psicose as the conversion substrate. Two mutant libraries were constructed through alanine scanning, saturation mutation, and rational design based on the analysis of the secondary structure , tertiary structure , and interactions with ligands of the enzyme. The yield of D -allose produced by these mutants was assessed; it was found that the conversion rate of mutant D325M to D -allose was increased by 55.73 %, and the D325S improved by 15.34 %, while mutant W184H increased by 10.37 % at 55 °C, respectively. According to modeling analysis, manganese (Mn 2+ ) had no significant effect on the production of D -psicose from D -psicose by L -Rhi. The results of molecular dynamics simulation demonstrated that the mutants W184H, D325M, and D325S had more stable protein structures while binding with the substrate D -psicose, as evidenced by its root mean square deviation (RMSD), root mean square fluctuation (RMSF), and binding free energy values. It was more conducive to binding D -psicose and facilitating its conversion to D -allose, providing the basis for the production of D -allose.
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高影响因子
Polymers
·
2023
·Vol. 15
·期 10
·2274
·
IF 5
Zipeng He,Binhua Mei,Hongmei Chu,Yanjun Hou,Haijun Niu
In this study, six conjugated oligomers containing D–A structures were synthesized using the Stille coupling reaction and named PHZ1–PHZ6. All the oligomers utilized demonstrated excellent solubilities in common solvents and notable color variations in the domain of electrochromic characteristics. By designing and synthesizing two electron-donating groups modified with alkyl side chains and a common aromatic electron-donating group, as well as cross-binding them with two electron-withdrawing groups with lower molecular weights, the six oligomers presented good color-rendering efficiencies, among which PHZ4 presented the best color-rendering efficiency (283 cm2·C−1). The products also demonstrated excellent electrochemical switching-response times. PHZ5 presented the fastest coloring time (0.7 s), PHZ3 and PHZ6 presented the fastest bleaching times (2.1 s). Following 400 s of cycling activity, all the oligomers under study showed good working stabilities. Moreover, three kinds of photodetectors based on conducting oligomers were prepared, and the experimental results show that the three photodetectors have better specific detection performances and gains. These characteristics indicate that oligomers containing D–A structures are suitable for use as electrochromic and photodetector materials in the research.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Yang Li,Bingxuan Ji,Ziyang Chen,Zhenghua Zhang
Secondary effluent from municipal wastewater treatment plants can be used to produce reclaimed water through membrane distillation (MD), providing a potential solution to the current global water crisis. However, membrane fouling over extended periods of operation reduces the separation performance of MD systems and significantly shortens the operational life-span of the membrane. Herein, in order to overcome these limitations, a novel surface-modified PTFE membrane was fabricated by depositing polydopamine and grafting dextro ( d )-tyrosine (Tyr/PDA@PTFE). This synergistic coating was designed to reduce surface hydrophobicity of the PTFE membrane and provide anti-adhesive properties for bacteria, while enhancing flux and anti-fouling performance during MD. The Tyr/PDA@PTFE membranes demonstrated enhanced MD performance and the Tyr-300/PDA@PTFE membrane (with d -tyrosine coating solution concentration of 300 μM) exhibited the best MD performance during direct contact membrane distillation (DCMD) of the secondary effluent, with the highest flux (49.1 LMH) compared with the pristine PTFE membrane (34.7 LMH), achieving a flux increase of 41.5%. Long-term DCMD operation showed that the Tyr-300/PDA@PTFE membrane exhibited improved anti-fouling performance compared with the pristine PTFE membrane, with 43.8% flux decay observed after three cycles of use, while the pristine PTFE membrane was unable to complete three cycles of use with an 87.2% decrease in flux observed by middle of the third round. The quality of permeate formed by the Tyr/PDA@PTFE membranes during MD, indicated that they could be operated stably for three cycles of use over a 40 h period, intercepting organic matter in the feed solution. The Tyr-300/PDA@PTFE membrane was especially effective for the removal of low molecular weight and humus-like substances, achieving rejection rates of 89.5% and 86.7%, respectively. Additionally, the Tyr/PDA@PTFE membrane carried the more negative charge and exhibited a high level of resistance to bio-adhesion. This study demonstrates the feasibility of use of this novel Tyr/PDA@PTFE membrane in MD, for the effective treatment of secondary effluent from wastewater treatment plants and the production of reclaimed water.
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高影响因子
LANGMUIR
·
2023
·
IF 3.9
Jie Ying,Zhen-Zhao He,Jiang-Bo Chen,Yu-Xuan Xiao,Xiao-Yu Yang
Many attempts have been made to enhance the relatively poor electrochemical activity of Ni3S2 for the oxygen evolution reaction (OER) by elevating the d-band center. Unfortunately, only limited success has been encountered thus far. Owning to the lower electronegativity and one less 3d electron relative to Ni, Fe shows great potentials in upshifting the overall d-band center of Ni3S2 when incorporating into its crystal structures. Herein, to enhance the intrinsic activity by elevating the d-band center, Ni3S2 nanosheets incorporated with suitable Fe content have been fabricated by a facile one-step solvothermal method. The obtained Fe-incorporated Ni3S2 catalyst exhibits an outstanding OER performance in alkaline media, only requiring 244 mV overpotential (with a reduction of 210 mV compared to Ni3S2) at 50 mA cm–2 in 1 M KOH and without obvious degradation after sustaining for a 60 h test at a voltage above 1.5 V. Ultraviolet photoemission spectroscopy and density functional theory calculations consistently demonstrate that the superior performance of Fe-incorporated Ni3S2 is attributed to the upshift of the d-band center on neutralizing the electron densities of Ni, which optimize greatly the adsorption energy of the intermediate (OOH*) in the rate-determining Volmer step.
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高影响因子
Biomaterials Advances
·
2023
·
IF 0
Xiaoyu Xia,Han Li,Xianbing Xu,Chao Wu,Zhenyu Wang,Junjie Yi,Guanghua Zhao,Ming Du
Recombinant human H-ferritin nanocage (rHuHF) loaded with natural antioxidative lycopene molecules (LYC) was successfully constructed for the first time, aiming to enrich LYC in the brain and explore the regulation mechanism of this nanoparticles on neurodegeneration. Here, the mouse model was constructed via D-galactose-induced neurodegeneration based on behavioural analysis, histological observation, immunostaining analysis, Fourier transform infrared microscopy, and Western blotting analysis for the regulation of rHuHF-LYC. rHuHF-LYC improved the behaviour of mice in a dose-dependent manner. Besides, rHuHF-LYC can attenuate neuronal damage, maintain the number of Nissl body, increase the level of unsaturated fat, inhibit the activation of glial cells, and prevent excessive accumulation of neurotoxic proteins in the hippocampus of mice. More importantly, synaptic plasticity was activated in response to the regulation of rHuHF-LYC with excellent biocompatibility and biosafety. This study proved the validity of the direct use of natural antioxidant nano drugs for treating neurodegeneration, providing a promising therapeutic option against further imbalances in the degenerative brain microenvironment.
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HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Huabo Huang,Renpeng Chen,Shuaiyi Yang,Liang Li,Yulan Liu,Juan Huang
To obtain the promising pseudocapacitance of MnO2, the composite hydrogel of MnO2 and polyaniline (PANI) was fabricated using in situ polymerization of aniline hydrochloride in the aqueous solution containing commercial MnO2 nanoparticles and additives. Both scanning electron microscopy and transmission electron microscopy results indicated that the composite hydrogel exhibited a 3-D porous structure, within which MnO2 nanoparticles were uniformly embedded. The investigations of cyclic voltammetry, galvanostatic charge−discharge, and electrochemical impedance spectroscopy demonstrated superior supercapacitor (SC) performance of the hydrogel electrode even with high loading. The electrode with loading of 1.5 mg cm–2 showed a favorable specific capacitance (293 F g–1, 10 mV s–1), which only decreased to 258 F g–1 when the loading of the electrode was seven times higher (10.8 mg cm–2). Furthermore, the hydrogel electrode displayed good cycle stability in the acidic solution (81% capacitance retention after 1000 charge/discharge cycles). The favorable electrochemical performance of the composite hydrogel should be attributed to the fast electron/ion transport and good protection for MnO2 in the 3-D porous structure. Due to the facile one-pot synthesis and optimized nanostructure, it could be expected that MnO2-embedded 3-D porous PANI composite hydrogels have great application in the field of high-performance electrode with high loading for SCs.
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高影响因子
Energy Technology
·
2018
·Vol. 6
·期 9
·1755-1762
·
IF 3.175
Kai Wu,Wenjun Ying,Zhengjun Shi,Haiyan Yang,ZhiFeng Zheng,JiaYan Zhang,Jing Yang
To screen and evaluate possible functional factors in the bamboo lignin moiety that could block non-productive adsorption of enzyme proteins on lignin, milled wood lignin (MWL) and Fenton oxidized lignin (FOLs) were prepared and incorporated in the enzymatic hydrolysis of Avicel. The addition of MWL decreased the 72 h glucose yields of cellulose from 57.1 % to 45.3 %, while FOLs effectively improved the enzymatic digestibility up to 69.5 %, which was 22 % higher than the system without the use of FOLs. The adsorption affinity and binding strength of cellulase with FOLs were lower than that with MWL. After Fenton pretreatment, hydrophilicity of lignins increased due to formation of C−O− and O−C=O bonds. Furthermore, high surface negative charges on FOLs resulted in strong electrostatic repulsion against the negatively charged cellulases. Finally, analysis of FOLs with 13C and 2D-HSQC NMR indicated that the cleavage of β-O-4 linkages and demethoxylation occurred, and that less condensed structures at the C β and C γ positions were observed. These oxidation reactions of the bamboo lignin lead to the formation of functional factors to alleviate irreversible adsorption of cellulase onto FOLs, and thus were responsible for promoting enzymatic digestibility efficiency.
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高影响因子
Contrast Media & Molecular Imaging
·
2018
·
IF 2.934
Shengjuan Luo,Jinsong Ding,Peiqi Wang,Zheng Wang,Xiaoqian Ma,Cejun Yang,Qi Liang,Pengfei Rong,Wei Wang
Perfluorooctyl bromide (PFOB) enclosed nanoparticles (NPs) as ultrasonic contrasts have shown promising results in the recent years. However, NPs display poor contrast enhancement in vivo. In this work, we used the copolymers poly(lactide-co-glycolide) carboxylic acid (PLGA-COOH) and poly(lactide-co- glycolide) poly(ethylene glycol) carboxylic acid (PLGA-PEG-COOH) as a shell to encapsulate PFOB to prepare a nanoultrasonic contrast agent. The NPs were small and uniform ( nm with a polydispersity index of ) with a complete shell nuclear structure under the transmission electron microscopy (TEM). In vitro, when concentration of NPs was ≥10 mg/ml and clinical diagnostic frequency was ≥9 MHz, NPs produced intensive enhancement of ultrasonic gray-scale signals. NPs could produce stable and obvious gray enhancement with high mechanical index (MI) (MI > 0.6). In vivo, the NPs offered good ultrasound enhancement in tumor after more than 24 h and optical imaging also indicated that NPs were mainly located at tumor site. Subsequent analysis confirmed that large accumulation of fluorescence was observed in the frozen section of the tumor tissue. All these results caused the conclusion that NPs encapsulated PFOB has achieved tumor-selective imaging in vivo.
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高影响因子
INTERNATIONAL IMMUNOPHARMACOLOGY
·
2018
·
IF 3.118
Jingjing Wen,Hongfa Lin,Mengshu Zhao,Liang Tao,Yunxia Yang,Xi Xu,Aiqun Jia,Jianfa Zhang,Dan Weng
Piceatannol , a natural derivative of resveratrol , has been shown to exert similar anti-oxidant and anti-inflammatory effects as resveratrol. However, it remains unknown whether piceatannol has hepatoprotective effect against acute liver injury. In this study, we investigated the in vivo effect of piceatannol on D-GalN/LPS-induced fulminant hepatic failure (FHF), and its in vitro effect on ER stress-inducing drug thapsigargin (TG)-induced proinflammatory cytokines production and ROS release. Our results indicated that piceatannol markedly decreased the mortality rate, reduced the serum levels of alanine transaminase and aspartic aminotransferase, ameliorated the liver damage induced by D-GalN/LPS in mice. In addition, piceatannol reduced the expression of proinflammatory cytokines, including TNF-α, IL-1β and IL-6, the expression of ER stress markers CHOP and phosphorylated-IRE1α, and the generation of oxidative stress in D-GalN/LPS-treated mouse liver. In vitro results were consistent with in vivo observations, demonstrating that piceatannol suppressed the secretion of proinflammatory cytokines, inflammasome activation and the production of ROS induced by TG with or without LPS priming in J774A.1 macrophages. Our study proposes piceatannol as a promising medication for preventing acute liver failure and the mechanisms may be related to its inhibitory effects on ER stress, inflammation and oxidative stress.
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高影响因子
INTERNATIONAL POLYMER PROCESSING
·
2018
·Vol. 33
·期 1
·127-134
·
IF 0.535
L. Q. Xu,Y. Q. Zhao
Commercial poly(l-lactic acid) (PLLA) was blended with different contents of graphene oxide-graft-poly(d-lactic acid) (GO-g-PDLA), which was synthesized via ring-opening polymerization using modified GO as initiator. PLLA and PLLA/GO-g-PDLA blend foams were prepared in a batch process via varying-temperature mode using supercritical carbon dioxide as physical foaming agent. The results showed that the addition of GO-g-PDLA in PLLA leads to the formation of stereocomplex (sc)-crystallites. Increase in the GO-g-PDLA content enhances the IR absorption, diffraction peak and melting peak corresponding to the sc-crystallites. The addition of GO-g-PDLA to PLLA leads to the decrease of the cell diameter, increase of the cell density and to a little change in expansion ratio, which is attributed to the fact that the enhancement of PLLA crystallization restricts cell growth and GO-g-PDLA acts as nucleation point.
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INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2018
·
IF 1.333
Qiao Zhang,Jianjun Fang,Wenjuan Liu,Yunhui Zhao,Tianlong Huang,Jiale Cui,Yun Yang,Zhihua Zhou
Bone tissue engineering is sought to apply strategies for bone defects healing biodegradable porous scaffolds without limitations and shortcomings. In this work, we have developed a novel maleic anhydride (MAH) and 1,4-butanediamine modified poly(lactide-co-glycolide) polymer (BMPLGA). The synthesized polymer was characterized by Fourier transform infrared spectrometry (FTIR), Nuclear magnetic resonance spectra (1H NMR), gel permeation chromatography (GPC) and contact angle measurements. In addition, cell morphologies in the extracts and cell cytotoxity were also studied. The results showed that the BMPLGA was successfully obtained by introducing MAH and 1,4-butanediamine into PLGA in bulk. The introduction of anhydride and amino groups improved the hydrophilicity of PLGA. Fibroblastic cells showed normal morphologies in BMPLGA extracts, and the BMPLGA materials showed no cell cytotoxicity. The synthetic BMPLGA material may have potentials for biomedical applications due to improving hydrophilicity.
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高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 13
·3975-3983
·
IF 6.1
Huiqin Yu,Fang Li,Jing Cao,Shifu Chen,Haili Lin
Developing highly active and stable bifunctional electrocatalysts for the oxidation of alcohols is critical for energy and chemical conversion. Herein, a NiCo2O4 nanowire on ultrathin porous carbon (NiCo2O4/C) was fabricated and exhibits superior electrocatalytic performance for both hydrogen evolution and benzyl alcohol (BA) oxidation in comparison with pristine NiCo2O4 free of carbon. It only needed 1.36 V vs. RHE to afford a current density of 50 mA cm−2 for BA oxidation. The overpotential for the HER (η10) is −93.0 mV vs. RHE. Furthermore, high yield (96.0%) and faradaic efficiency (98.6%) of benzoic acid were achieved in 10 consecutive stability tests. The outstanding electrocatalytic activity can be attributed to the following aspects: (1) the hierarchical architecture exposed more catalytic active sites and enhanced mass transport; (2) ultrathin porous carbon strengthened the affinity for the reaction medium; (3) strong electronic interactions optimized the energy band structure. DFT simulations proved that the Gibbs free energy of the rate-determining step was reduced when coupling with ultrathin porous carbon, thus lowering the energy barrier and accelerating the reaction process. Theoretical calculations further reveal that the moderate downshift in the Ed energy levels, which balance the adsorption and desorption of the intermediates, is the intrinsic reason for the promoted oxidation activity. This work could provide valuable insights into the design of highly efficient bifunctional electrocatalysts.
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