Nature Microbiology
·
2020
·Vol. 5
·期 8
·1040-1050
·
IF 15.54
Song Meirong,Liu Yuan,Huang Xiaoyong,Ding Shuangyang,Wang Yang,Shen Jianzhong,Zhu Kui
The rapid emergence and dissemination of multidrug-resistant (MDR) bacterial pathogens pose a serious threat to global healthcare. One particular concern is the carbapenem-resistant Enterobacteriaceae (CRE), a group of Gram-negative bacteria that have evolved resistance to all or nearly all available antibiotics. Coupled with the fact of barren antibiotic development pipeline nowadays, a critical approach is to revitalize existing antibiotics using antibiotic adjuvants. We found a short linear antibacterial peptide (SLAP)-S25 carrying four non-natural amino acids of 2,4-diaminobutanoic acid (Dab), which solely showed weak antibacterial activity but boosted the efficacy of antibiotics covering all major classes, including cefepime, colistin, ofloxacin, rifampicin, tetracycline and vancomycin, against MDR Gram-negative pathogens. Mechanistic studies showed that SLAP-S25 triggers membrane damage by binding to both lipopolysaccharide (LPS) in the outer membrane and phosphatidylglycerol (PG) in bacterial cytoplasmic membrane, to potentiate antibiotic efficacy through collaborative strategies. Lastly, SLAP-S25 effectively enhanced the activity of colistin against MDR Escherichia coli -associated infections in three animal models. Our findings provide a potential therapeutic option using existing antibiotics in combination with broad-spectrum antibiotic adjuvants, to address the prevalent infections caused by MDR Gram-negative pathogens worldwide.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 31
·39186-39197
·
IF 3.056
Zhao Shiyin,Li Shun,Zhao Zhicheng,Su Yiping,Long Yangke,Zheng Zuquan,Cui Daling,Liu Yong,Wang Chunfei,Zhang Xuanjun,Zhang Zuotai
Adsorption and photocatalysis are promising strategies to remove pollutants of dyes and antibiotics from wastewater. In this study, we demonstrate a rapid microwave-assisted hydrothermal route for the assembly of 2D copper-porphyrin Metal-Organic Frameworks (Cu-TCPP MOFs) within 1 h. The resulting 2D Cu-TCPP nanosheets with excellent crystallinity and a large surface area (342.72 m 2 /g) exhibited outstanding adsorption performance for typical dyes with adsorption capacities of about 185 mg/g for rhodamine B, 625 mg/g for methylene blue, and 290 mg/g for Congo red, respectively, as well as for representative antibiotics with adsorption capacities of about 130 mg/g for oxytocin, 150 mg/g for tetracycline, and 50 mg/g for norfloxacin, respectively. Meanwhile, the as-prepared 2D Cu-TCPP showed good photocatalytic degradation activity of pollutants after adsorption under irradiation by visible light, reaching removal efficiencies of 81.2 and 86.3% toward rhodamine B and norfloxacin, respectively. These results demonstrate the promising potential of 2D Cu-TCPP for use in the removal of contaminants from wastewater.
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Chinese Medicine
·
2020
·Vol. 15
·期 1
·1-19
·
IF 2.96
Chang Shanquan,Wang Mei,Tian Yushan,Qi Jin,Qiu Zhixia
Background Zengye decoction (ZYD) has been widely used in the treatment of type 2 diabetes mellitus (T2DM). Exploring the fate of various components of ZYD in vivo is of considerable significance for pharmacological research and molecular mechanism elaboration. However, the systematic analysis on the metabolic behavior of chemical components of ZYD in T2DM rats has not been reported. Methods To screen and characterize the complex chemical compositions of ZYD, and metabolism fate in plasma, urine, bile, and feces of T2DM rats, the model of T2DM rats was prepared. A rapid procedure using high-performance liquid chromatography coupled with electrospray ionization quadrupole time of flight tandem mass spectrometry (HPLC-ESI-Q-TOF–MS/MS) was established. Data were acquired and analyzed by Agilent MassHunter Workstation Qualitative Analysis software version B.07.00 and PCDL manager B.07.00. Results A total of 80 compounds were identified or tentatively characterized in ZYD, 31 more than previously detected. Besides, 36 prototype components and 49 metabolites of ZYD were found and characterized in T2DM rats, and the proposed fragmentation pathways and possible metabolic behaviors of the main types of compounds were described. Conclusions This study developed the understanding of the composition of ZYD as well as the cleavage rules and metabolic pathways of the prototype compounds. Besides, this study provided abundant data for further research and for study of the metabolism of traditional Chinese medicine prescriptions.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 11
·11990-12000
·
IF 3.056
Cui Yanping,Thathsarani Nimesha,Peng Liang,Gao Ya,Lei Lidan,Zhou Zhengwei,Liang Lili,Shi Xiaoyan
Innovative paramagnetic one-dimensional (1-D) core-shell Fe-Ag@AgCl visible light-driven photocatalysts are synthesized through a template-assisted electrodeposition method trailed by FeCl 3 in-situ oxidation. The metallic nature of Fe-Ag@AgCl is confirmed through scanning electron microscopy (SEM) and crystal nature through X-ray diffraction (XRD). The controllable diameter of Fe-Ag is obtained through the selection of hollow size of the polycarbonate (PC) template. Electron impedance spectroscopy (EIS) confirms through the introduction of Fe to the Ag core that has prolonged the recombination of electron and hole. Escherichia coli ( E. coli ) are employed as the target bacteria to evaluate the photocatalytic disinfection performances. A total of 1.30 mg of Fe-Ag@AgCl is proved to be able to completely inactivate 10 7 CFU (colony forming units)/mL after 120 min of visible light irradiation. The transition electron microscopy (TEM) confirms the stability of the material after the photo reaction. As Fe-Ag@AgCl possesses magnetic properties, the material is recovered through the application of an external magnetic field. SEM images and results of 3D emission extraction matrix (EEM) depict that the bacteria cell death is caused by membrane permeability changes caused by the reduction of membrane associated proteins.
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CELLULOSE
·
2020
·Vol. 27
·期 6
·3455-3468
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IF 4.21
Xue Chao-Hua,Wu Yue,Guo Xiao-Jing,Liu Bing-Ying,Wang Hui-Di,Jia Shun-Tian
Functional textiles are ideal substrates for wearable electronics. Herein, superhydrophobic, flame-retardant and conductive cotton fabrics were fabricated by sequential assembly of poly(ethylenimine), ammonium polyphosphate and carbon nanotubes, followed by post-treatment with poly(dimethylsiloxane). The resulting fabrics possessed excellent superhydrophobic stability toward acid, alkali, organic solvent, UV irradiation, abrasion and long-time laundering. Meanwhile, when suffering to fire, the coated fabric could generate an efficient char layer and extinguish the fire to protect the cotton fiber from forming flame. Furthermore, this conductive cotton fabric exhibited stable sensing ability in contact with water droplets, showing wide potential application in wearable electronics as multifunctional smart textiles.
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CELLULOSE
·
2020
·Vol. 27
·期 6
·3427-3442
·
IF 4.21
Liu Xiao-hui,Ding Chen,Peng Bo,Ren Yuan-lin,Cheng Bo-wen,Lin Sheng-gen,He Ju,Su Xiao-wei
In this paper, a simple and facile polyol sorbitol was employed to design and synthesize a novel flame retardant containing phosphorus and nitrogen by the reaction of sorbitol with phosphoric acid and urea. The obtained sorbitol-based flame retardant was then used to treat lyocell fibers by a pad-dry-cure procedure. Formaldehyde and other harmful substances were not used during the preparation of flame retardant and modified fibers. For this strategy, only water is used as solvent, and the conditions are mild, safe and environmentally friendly. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses show that the sorbitol-based flame retardant was successfully grafted onto lyocell fibers. Scanning electron microscopy analyses show that the surface morphology of the treated fibers remained unchanged. Thermogravimetric analyses imply that the residue of the treated fibers increases considerably. Vertical combustion and limit oxygen index results indicate that the treated fibers possess excellent flame retardant and durable properties. Based on the results of pyrolysis gas chromatography–mass spectrometry, thermogravimetric-infrared and Raman spectroscopy, the flame retardant operates in condensed phase and gas phase during burning of treated fibers.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 2
·1-9
·
IF 6.232
Hu Peng,Zhu Xiaoming,Luo Xiaohui,Hu Xiaofeng,Ji Liudi
The authors describe a novel electrochemical determination method for bisphenol A (BPA) based on the electrosynthesised Cu-BTC (H 3 BTC: trimesic acid) films. Using H 3 BTC as the ligand, Cu(NO 3 ) 2 as the precursor of copper ions, and triethylamine hydrochloride (Et 3 NHCl) as the probase source, Cu-BTC films were directly deposited on glassy carbon electrode (GCE) surface via cathodic electrochemical reduction under −1.30 V. Considering the electrocatalytic activity of metal center Cu 2+ , Cu-BTC films were applied to construct the electrochemical determination platform for BPA. Chronocoulometry and electrochemical impedance spectroscopy were used to study the signal enhancement mechanism. The determination conditions were optimized. As a result, a sensitive electrochemical method was constructed for BPA. The peak currents, best measured at voltage of 0.496 V vs. SCE (KCl saturated calomel reference electrode), increase linearly in the range from 5.0 to 2000 nM. The value of determination limit is 0.72 nM. The proposed method was successfully applied to determine BPA in spiked urine, spiked waste water samples and plastic products. The results were in good agreement with those obtained for the same samples by high-performance liquid chromatography (HPLC).
Schematics for the construction of electrochemical determination for bisphenol A.
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 7
·1878-1889
·
IF 2.482
Song Zhimin,Zhu Xiaodi,Zeng Yusheng,Wang Azhu,Li Shikuo,Fan Yi,Cai Mengdie,Cheng Qin,Wei Yuxue,Sun Song
Abstract Cocatalysts play important roles in photocatalytic and photoelectrochemical water splitting reactions. However, the formation of well-defined junctions between low dimensional semiconductors and cocatalysts is still challenging. In this study, CdS nanorod photoanodes loaded with cobalt phosphate (CoPi) cocatalyst were synthesized by a facile two-step route, in which CdS nanorods were prepared using a hydrothermal method followed by photo-assisted electrodeposition of CoPi. It was found that the formation of intimate junctions between CoPi and CdS nanorods in the form of Co–S bonding effectively facilitated the charge separation and lowered the activation energy of the water oxidation reaction. This resulted in highly efficient and stable photoelectrochemical water splitting on the CdS photoanode. The optimal CdS/CoPi photoanode showed a maximum photocurrent of 4.7 mA/cm 2 at 0 V versus reversible hydrogen electrode under an AM 1.5 G solar simulator, which was 5.5-fold higher than that of bare CdS photoanode. This work expands the potential application of the cocatalyst CoPi in CdS photoanode systems and improves our understanding of the nature of cocatalysts with well-defined interface junctions in semiconductors. Graphic Abstract Well-defined interfacial junction with Co–S bonding over cobalt phosphate cocatalyzed CdS nanorod photoanode facilitates the charge separation and lowers the activation energy, thus achieving a considerable photocurrent of 4.7 mA/cm 2 at 0 V vs. RHE.
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INFLAMMATION
·
2021
·Vol. 44
·期 5
·2018-2032
·
IF 4.092
Zhou Changkai,Gao Jing,Ji Hongyan,Li Wenjing,Xing Xiaomin,Liu Donghua,Guo Qie,Zhou Lihua,Jing Fanbo
Previous studies have shown that benzoylaconine (BAC), a representative monoester alkaloid, has a potential anti-inflammatory effect. This study investigated the underlying molecular mechanisms using the mode of LPS-activated RAW264.7 macrophage cells. Our findings showed that BAC significantly suppressed the release of pro-inflammatory cytokines and mediators, including IL-6, TNF-α, IL-1β, ROS, NO, and PGE 2 . BAC treatment also effectively downregulated the elevated protein levels of iNOS and COX-2 induced by LPS in a dose-dependent manner. In this study, we found that BAC inhibited LPS-induced NF-κB activation by reducing the phosphorylation and degradation of IκBα by western blotting and blocking the nuclear translocation of p65 using an immunofluorescence assay. The elevated protein levels of JNK, p38, and ERK phosphorylation after LPS stimulation were restored effectively by BAC treatment. The protein expression of Toll-like receptor 4 (TLR4) and LPS-induced phosphorylation of TAK1, which is a crucial upstream regulatory factor of TLR-induced MAPK and NF-κB signaling, were inhibited by BAC in activated RAW264.7 macrophages. Moreover, BAC decreased the levels of TAK1 phosphorylation and pro-inflammatory cytokines and mediators associated with MAPK and NF-κB activation, similar to TLR4 inhibitor TAK-242. These findings demonstrated that BAC exhibited an anti-inflammatory effect by the inhibition of TLR-induced MAPK and NF-κB pathways, indicating that it could potentially be used for treating inflammatory diseases.
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CELLULOSE
·
2021
·Vol. 28
·期 12
·7995-8008
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IF 5.044
Gao Qian,Wang Jiabao,Liu Jing,Wang Yuda,Guo Jinge,Zhong Ziyi,Liu Xinliang
Cellulose nanocrystals (CNCs) with high crystallinity exhibit high mechanical stiffness and strength. However, the high dispersibility of CNCs results in limited spinnability and orientation. In this study, oxidized nanocellulose was selected to obtain regionally oxidized CNCs (RO-CNC) with carboxyl groups appended. For the formation of orientable and extensible RO-CNC filaments, chitosan was introduced as the sheath solution to induce orientation by electrostatic action. The chemical structures were analyzed by Fourier transform infrared spectroscopy. The morphology of the oriented CNCs filaments was characterized by scanning electron microscopy and wide-angle X-ray scattering. Analysis of the relationship between the mechanical strength and the CNCs directional arrangement revealed that the mechanical strength of the composite fibers increased with the injection speed ratio as a result of the orientation of the RO-CNC. The mechanical strength of the oriented reinforced composite filaments reached as high as 104 MPa with an orientation index of 0.73. The tensile strength and elastic modulus of the filaments increased by 33% and 20%, respectively, compared to the unmodified CNCs spun fiber. Graphic abstract
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Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 12
·10701-10710
·
IF 4.987
Zeng Qin,Du Zhenyu,Luo Ligang
In this study, different bimetallic (Ru, Pd, and Pt) catalysts over a variety of supports (activity carbon, γ-Al 2 O 3 , TiO 2 , HZSM-5) were employed to improve the kraft lignin depolymerization process using isopropanol as in situ hydrogen source. The effect of catalysts was firstly investigated, which suggested that 1wt%Ru-1wt% Pd/HZSM-5 promoted the hydrogenolysis and hydrodeoxygenation effect on conversion of kraft lignin (95.86 wt%) and the selectivity of aliphatic alcohol (26.92 wt%) and hydrocarbon monomers (35.73 wt%), respectively. The effect of temperature and reaction time were also discussed, which indicated that the high temperature (250 to 310 °C) promoted the hydrogenolysis process; while the temperature is higher than 310 °C, the repolymerization process was appeared, leading to the decreasing yield of total monomers. For the influence of reaction time, it was noted that the optimal reaction time to acquired high yield and selectivity of aliphatic alcohol and hydrocarbon monomer was 120 min. It was also conducted FTIR and 2D HSQC NMR analysis to understand the effective depolymerization of the major linkages with attacked by the Ru-Pd/HZSM-5 catalyst, which was corresponding with the results with GC–MS. Graphical abstract
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CLAYS AND CLAY MINERALS
·
2021
·Vol. 69
·期 4
·434-442
·
IF 1.609
Zhang Mingzhu,Sun Shiyong,Lv Rui,Golubev Yevgeny Aleksandrovich,Wang Ke,Dong Faqin,Kotova Olga Borisovna,Kotova Elena Leonidovna
Lipase is an industrial enzyme, the catalytic efficiency of which is restricted by various environmental factors. To improve this efficiency, immobilization technology has been utilized in the past to improve the stability of lipase in harsh conditions. Immobilization technology can be divided into physical methods and chemical methods. Some unsolved problems remain in current immobilization technology. The interaction between enzyme and immobilization support is weak and reversible during physical adsorption, resulting in poor stability of the immobilized enzyme and the contamination of substrate solution by leached enzymes. In chemical methods, enzyme-active sites might be inactivated due to the chemical reactions between enzyme molecules and support, resulting in a decrease in the enzymes’ catalytic activity (Liu et al., 2018a ). The objective of the current study was to construct a nanostructured lipase via Mg-amino-clay as a carrier and improve the catalytic activity and stability of lipase by immobilization. Lipase produced by Aspergillus oryzae was immobilized on aminopropyl functionalized magnesium phyllosilicate (a 2:1 trioctahedral talc-like silicate Mg-amino-clay) via a 1-(3-Dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) coupling agent. The physical and chemical properties of the Mg-amino-clay and Mg-amino-clay-based nanostructured biocatalyst (Mg-clay-lipase) were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Optimal immobilization conditions were determined by taking into account the following variables: amount of initial lipase, EDC concentration, and reaction time. The results revealed that the optimum temperature, pH, and thermal stability of Mg-clay-lipase were greater than equivalent values for free lipase under optimal conditions (described below – Process for Immobilization of Lipase on Mg-amino-clay ). The Michaelis-Menten constant (K m ) values were 5.25 mM and 7.42 mM while the maximum reaction rates ( v max ) were 30.58 mM/(L·min) and 55.87 mM/(L·min) for free lipase and Mg-clay-lipase, respectively. The present study provided a new nanostructured biocatalyst and demonstrated that the enzyme activity and stability of Mg-clay-lipase were superior to those of free lipase due to the mechanism of 'interface activation'.
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