SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2023
·
IF 4.4
Zhen Lin,Chuangui Cai,Wei Chen,Qian Deng,Jialin Yang,Kaiyuan Huang,Haohua Deng,Xinhua Lin,Wei Chen,Wensong Yao
Chemiluminescence (CL) intensity of luminol-H 2 O 2 system was dramatically enhanced by cetyltrimethylammonium bromide (CTAB) micelle-mediated 6-aza-2-thiothymine-protected gold nanoclusters (ATT-AuNCs). It is proved that spherical micelles of CTAB in aqueous solution improved the dispersity of ATT-AuNCs, thus enhancing their catalytic activity, which brought in the increased CL intensity of luminol-H 2 O 2 system. Carbazochrome sodium sulfonate (CSS) with a hemostatic containing tetrahydroindole structure broke the spherical micelles and notably quenched the CL intensity of luminol-H 2 O 2 -CTAB-ATT AuNCs system. Based on these results, a simple, fast, and sensitive CL method has been developed for the detection of CSS with a linear range of 0.25–25 μM and a detection limit of 0.11 μM. The method has also been successfully applied to the determination of CSS in serum with satisfied recoveries in the range of 89.6 % to 103.7 %. This study not only provides an effective approach for CSS detection but also paves the way for AuNCs-based CL applications.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Qun Wang,Zhaomei Wang,Jun Song,Kangjie Xu,Wenni Tian,Xu Cai,Jiamei Mo,Yong Cao,Jie Xiao
A nanolipidcarrier (NLC) loaded homogalacturonan enriched pectin (citrus modified pectin, MCP4) hydrogel was designed as a novel colon inflammation site-specific oral delivery system for 6-gingerol (6G) (6G-NLC/MCP4 hydrogel) administration, and its colitis alleviation effect were investigated. 6G-NLC/MCP4 exhibited typical “cage-like” ultrastructure with 6G-NLC embedded in the hydrogel matrix as observed by cryoscanning electron microscope. And due to the homogalacturonan (HG) domain in MCP4 specifically combined with Galectin-3, which is overexpressed in the inflammatory region, the 6G-NLC/MCP4 hydrogel targeted to severe inflammatory region. Meanwhile, the prolonged-release characteristics of 6G-NLC provided sustained release of 6G in severe inflammatory regions. The matrix of hydrogel MCP4 and 6G achieved synergistic alleviation effects for colitis through NF-κB/NLRP3 axis. Specifically, 6G mainly regulated the NF-κB inflammatory pathway and inhibited the activity of NLRP3 protein, while MCP4 regulated the expression of Galectin-3 and peripheral clock gene Rev-Erbα/β to prevent the activation of inflammasome NLRP3.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Huimin Yang,Xin Liu,Jihui Wang,Wenbin Hu
The following study is conducted to improve the corrosion resistance of magnesium alloy. First, ZnAl layered double hydroxide (ZnAl LDH) film was prepared on AZ61 magnesium alloy by using hydrothermal method. Then, as-prepared ZnAl LDH was put into 2-methylimidazole (2-mIm) solution to synthetize ZIF-8 film (ZIF-8/LDH). Finally, ZIF-8/LDH film synthesized ZIF-8-DMBIM film (ZIF-8-DMBIM/LDHs) via a shell-ligand-exchange-reaction in the methanol solution containing 5, 6-dimethylbenzimidazole (DMBIM). The surface morphology, structure, and composition of the composite film were observed and determined by scanning electronic microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. The wettability of composite film was measured by using a water contact angle meter, and the corrosion resistance of the composite film was estimated by the polarization curve and electrochemical impedance spectroscopy techniques. Results show that the prepared ZIF-8-DMBIM/LDH composite film has a dense hexagonal plate morphology with a two-layer structure and a thickness of 3.5 μm. Compared with ZnAl LDH and ZIF-8/LDH films, ZIF-8-DMBIM/LDH composite film has a high contact angle (115.7°), low corrosion current density, and high corrosion potential and polarization resistance due to its near-smooth surface, dense two-layer structure, and hydrophobic characters.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Weizhen Zhang,Zhilong Yang,Yuan Li,Qi Zhang,Shijun Zhang,Liqun Zhang
Epoxidized silicone rubber with an epoxy content of 5% (ESR-5) was introduced to improve the compatibility of the polyamide 6 (PA6)/poly(dimethylsiloxane) (PDMS) composite. The effects of the ESR-5 on the molecular structure, interfacial morphology, and toughness and thermal properties of the PA6/PDMS composite were investigated using nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic thermomechanical analysis (DMA). The FT-IR spectra and torque rheological testing confirmed the reaction between the epoxy group of ESR-5 and the carboxyl group at the end of PA6. The AFM and SEM images confirmed that the ESR-5 altered the interfacial thickness and remarkably decreased the average size of the dispersed rubber particles, which enhanced the interfacial compatibility. At a rubber content of 20% by weight in PA6/PDMS composites, the optimum impact strength at −60 °C, which is 469% higher than pure PA6, was obtained with an ESR-5 content of 50% in rubber phase.
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APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Yonghuan Zhao,Yang Meng,Pengxiang Yu,Xiaoxiao Hu,Juanjuan Su,Jian Han
The demand for photothermal fabrics requires more efficient photothermal nanoparticles and more stable interface binding fastness. Nanohybrid coating is considered as used as an efficient method to reach the goal. In this study, a nanohybrid of reduced graphene oxide-zinc-aluminum layered double metal hydroxide (RGO-LDH) was filled to WPU coating to prepare the photothermal textiles. RGO-LDH nanohybrid was surface modified by polydopamine (PDA) to improve the dispersion in WPU. In comparison to the pure WPU film, the WPU nanocomposite film exhibited enhanced water resistance, mechanical properties, and scratch resistance with the inclusion of nanohybrid filler at a 1 wt% concentration. Furthermore, the nanohybrid/WPU coated fabric showed excellent anti-ultraviolet (anti-UV) and photothermal conversion performance. The surface temperature of the nanohybrid/WPU coated fabric rose to 64 °C when exposed to a xenon lamp. After undergoing various durability tests including wearing, washing, folding, and bending, it was confirmed that the modified fabric had outstanding photothermal stability. This work provides a new strategy to fabricate the photothermal textile with excellent warming effect and weather resistance.
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JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Hong Zhu,Yunxi Li,Nanjun Chen,Chuanrui Lu,Chuan Long,Ziming Li,Qiao Liu
Responding to the insufficient durability and mechanical stability of anion exchange membranes (AEMs) used in alkaline membrane fuel cells (AMFCs), a series of poly(biphenyl 6-azaspiro[5.5] undecanium) (PB-ASU) membranes were prepared by strong-acid condensation. For improving the comprehensive performance of the PB-ASU membrane, a profitably-crosslinked poly(biphenyl piperidinium) (PBP) segment was introduced to the PB-ASU backbone to fabricate a physical-crosslinked PB-ASU-PBP copolymer . The crosslinked PBP segment improves the dimensional stability and film-forming properties of PB-ASU-PBP membrane, but sacrifices a part of alkaline stability. As expected, all of the PB-ASU and PB-ASU-PBP membranes show superb alkaline stability, only tiny degradations of the PB-ASU (<6%) and PB-ASU-PBP (<9%) were detected by 1 HNMR spectroscopy after alkaline treatment in 3 M NaOH aq at 80 °C for 2000 h. Besides, these PB-ASU-PBP membranes show good OH − conductivity of 116.1 mS/cm, and realize a maximum power density of 87 mW/cm 2 at 80 °C. All these results point out that these long-lifetime PB-ASU-PBP membranes are promising for AEM applications.
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APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2019
·
IF 4.077
Rongshui Wang,Jihong Yi,Jinmeng Shang,Wenjun Yu,Zhifeng Li,Haiyan Huang,Huijun Xie,Shuning Wang
Agrobacterium tumefaciens S33 degrades nicotine via a novel hybrid of the pyridine and the pyrrolidine pathways. The hybrid pathway consists of at least six steps involved in oxidoreductive reactions before the N-heterocycle can be broken down. Collectively, the six steps allow electron transfer from nicotine and its intermediates to the final acceptor O2 via the electron transport chain (ETC). 6-Hydroxypseudooxynicotine oxidase, renamed 6-hydroxypseudooxynicotine dehydrogenase in this study, has been characterized as catalyzing the fourth step using the artificial electron acceptor 2,6-dichlorophenolindophenol. Here, we used biochemical, genetic, and liquid chromatography-mass spectrometry (LC-MS) analyses to determine that 6-hydroxypseudooxynicotine dehydrogenase utilizes the electron transfer flavoprotein (EtfAB) as the physiological electron acceptor to catalyze the dehydrogenation of pseudooxynicotine, an analogue of the true substrate 6-hydroxypseudooxynicotine, in vivo, into 3-succinoyl-semialdehyde-pyridine. NAD(P)+, O2, and ferredoxin could not function as electron acceptors. The oxygen atom in the aldehyde group of the product 3-succinoyl-semialdehyde-pyridine was verified to be derived from H2O. Disruption of the etfAB genes in the nicotine-degrading gene cluster decreased the growth rate of A. tumefaciens S33 on nicotine but not on 6-hydroxy-3-succinoylpyridine, an intermediate downstream of the hybrid pathway, indicating the requirement of EtfAB for efficient nicotine degradation. The electrons were found to be further transferred from the reduced EtfAB to coenzyme Q by the catalysis of electron transfer flavoprotein:ubiquinone oxidoreductase. These results aid in an in-depth understanding of the electron transfer process and energy metabolism involved in the nicotine oxidation and provide novel insights into nicotine catabolism in bacteria.IMPORTANCE Nicotine has been studied as a model for toxic N-heterocyclic aromatic compounds. Microorganisms can catabolize nicotine via various pathways and conserve energy from its oxidation. Although several oxidoreductases have been characterized to participate in nicotine degradation, the electron transfer involved in these processes is poorly understood. In this study, we found that 6-hydroxypseudooxynicotine dehydrogenase, a key enzyme in the hybrid pyridine and pyrrolidine pathway for nicotine degradation in Agrobacterium tumefaciens S33, utilizes EtfAB as a physiological electron acceptor. Catalyzed by the membrane-associated electron transfer flavoprotein:ubiquinone oxidoreductase, the electrons are transferred from the reduced EtfAB to coenzyme Q, which then could enter into the classic ETC. Thus, the route for electron transport from the substrate to O2 could be constructed, by which ATP can be further sythesized via chemiosmosis to support the baterial growth. These findings provide new knowledge regarding the catabolism of N-heterocyclic aromatic compounds in microorganisms.
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AUSTRALIAN JOURNAL OF CHEMISTRY
·
2019
·Vol. 72
·期 7
·533-541
·
IF 1.226
Sai Huang,Mei Yang,Xin-Yu Deng,Qian Jiang Zhu,Ying Huang,Zhu Tao,Kai Chen
In the present work, a host–guest system of a hemimethyl-substituted cucurbit[6]uril derived from 3α-methyl-glycoluril (HMeQ[6]) and a hemicyanine dye, trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (t-DSMI) showing strong fluorescence emission has been evaluated as a fluorescent probe. The results of a preliminary systematic study on the detection of a series of inorganic anions have revealed that this Q[n]-based host–guest fluorescent probe shows clear responses to BF4− and H2PO4− anions through distinct fluorescence quenching. Application of this Q[n]-based host–guest interaction system in anion recognition or detection opens a new avenue in Q[n] chemistry.
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CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Shuangyu Xiong,Luminita Marin,Lian Duan,Xinjian Cheng
Nitroaromatic compounds, especially 2, 4, 6-trinitrophenol, have strong biological toxicity and explosive risks, so the detection of 2, 4, 6-trinitrophenol exhibit importantly practical and scientific significance. In this work, three fluorescence functionalized chitosan CNS 3 , CNS 4 and CNS 5 were prepared using chitosan as matrix. When 2, 4, 6-trinitrophenol (TNP) and/or p-nitrophenol (4-NP) was present in spot, these fluorescent chitosan sensors produced notable fluorescence quenching. It renders the chitosan sensing ability to detect TNP and 4-NP selectively and sensitively. The sensing mechanism is investigated as well. When introduced electron-rich moieties to the fluorescent chitosan, the sensitive detecting ability could be obtained. Excellent recognition ability could reach as low as 0.28 μM. The fluorescence fictionalization cause slight influence to the gel performance of chitosan.
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INFLAMMOPHARMACOLOGY
·
2018
·Vol. 27
·期 5
·969-974
·
IF 3.304
Zhao Mingyi,Zhou Peng,Yu Jun,James Asenso,Xiao Feng,Wang Chun,Wei Wei
Paeoniflorin-6′-O-benzene sulfonate (code: CP-25) is a novel ester derivative of paeoniflorin (Pae). Compared to Pae, CP-25 has higher lipid solubility, bioavailability and better bioactivity. However, the tissue distribution and excretion of CP-25 still remain unknown. The LC–MS method was applied to investigate the tissue distribution and excretion of CP-25 in rats. As such, 50 mg/kg of CP-25 and Pae were administered to rats in multiple doses via an oral route. CP-25 and Pae were distributed widely and rapidly in all the tested tissues. Compared with Pae, the concentrations of CP-25 were almost increased evidently in most tissues. The highest CP-25 level was found in the liver (1476.33 ± 535.20 ng/g, male; 1970.38 ± 177.21 ng/g, female) at 3 h, and a high concentration of CP-25 was detected in male and female intestine, synovium, muscle, lung, and brain. Following a single oral dose of 50 mg/kg of CP-25 in rats, the total excretion of CP-25 was merely 21.8% (18.40, 3.19 and 0.22% for feces, bile and urine, respectively) in males; and was approximately 21.3% (14.04, 7.16 and 0.14% for feces, bile and urine, respectively) in females. The results indicated that the CP-25 concentration was higher in major tissues than Pae; CP-25 was primarily excreted through the feces; and there were gender-related differences in the tissue distribution and excretion.
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POLYMER
·
2018
·
IF 3.483
Miaojun Xu,Kun Ma,Dawei Jiang,Jiaoxia Zhang,Min Zhao,Xingkui Guo,Qian Shao,Evan Wujcik,Bin Li,Zhanhu Guo
The effects of phosphazene based epoxy resin hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene (CTP-EP) as a synergistic agent on fire retardancy, thermal and mechanical properties of polyamide 6/aluminum diethylphosphinate (PA6/AlPi) composites were investigated. AlPi and CTP-EP presented an obviously synergistic flame retardant effect for the PA6 matrix. The PA6/AlPi/CTP-EP composites with a thickness of 1.6 mm successfully passed UL-94 V-0 rating with the limiting oxygen index value of 31.0% when the loading amount of AlPi/CTP-EP (mass fraction of 97/3) was 11 wt%. The incorporated CTP-EP improved the complex viscosity of PA6/AlPi/CTP-EP composites due to the chain extending reaction between the epoxide groups of CTP-EP and the terminal groups of PA6 matrix. The CTP-EP stimulated the formation of more sufficient and compact char layer during combustion. The higher melt viscosity and more compact char layer of PA6 composites further inhibited the volatilization of flammable gases, thus the ignition time of PA6/AlPi/CTP-EP composites was prolonged and the released heat was reduced. The introduction of CTP-EP simultaneously enhanced the flame retardant and mechanical properties of PA6/AlPi/CTP-EP composites compared with that of PA6/AlPi composites.
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Frontiers in Microbiology
·
2018
·
IF 4.019
Chen Xin,Tang Hongzhi,Liu Yongdi,Xu Ping,Xue Yong,Lin Kuangfei,Cui Changzheng
3-Hydroxybenzoate 6-hydroxylase, an NADH-dependent flavoprotein, can convert 3-hydroxybenzoate which is an important intermediate in the biodegradation of many aromatic hydrocarbons. 3-Hydroxybenzoate is metabolized by entering the TCA cycle through the gentisate pathway. We found a putative 3HB6H gene from a cluster that potentially encodes for gentisic acid degradation from a halophilic Martelella sp. strain AD-3. The corresponding protein was expressed with an N-terminal His-tag and purified by Ni2+-nitrilotriacetic acid affinity chromatography. The protein showed an overexpressed band of about 46 kDa by SDS–PAGE, and it was also proven that the enzyme contains FAD by absorption spectroscopy and HPLC analysis. The optimal activity of 3HB6H from strain AD-3 was observed in phosphate buffer (pH 8.0) at 37∘C without salinity (NaCl) and metal salts. The Km values of 3-hydroxybenzoate 6-hydroxylase were determined to be 72.6 ± 10.1 μM and 104.1 ± 18.2 μM for 400 μM NADH and 3-hydroxybenzoate, respectively. Site-directed mutagenesis showed that residues 305, 306 and 308 are important for FAD binding. In addition, we found that Tyr221 and Gln305 of 3HB6H from strain AD-3 are involved in substrate binding.
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