APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 106
·期 7
·2381-2391
·
IF 5.56
Yin Zhongwei,Gao Lin,Zhu Li,Peng Xingqiao,Zhan Xiaobei
Abstract Polysialic acid (PSA) is a long-chain linear amino polysaccharide with broad application prospects; however, its relatively low molecular weight limits its application range. This study aims to explore a new fermentation method of combining the three-phase pH control strategy, three-phase mixing speed control strategy, and exogenous substance to produce high molecular weight PSA. In brief, Escherichia coli K235 6E61 (CCTCC M208088) was used as a fermentation strain. 3 g·L −1 Na 5 P 3 O 10 was added to the initial medium. At 0–12 h, the mixing speed was controlled to 250 r·min −1 , and the pH was maintained at 7.2. At 12–20 h, the mixing speed was increased to 400 r·min −1 , the pH was changed to 6.8, and 0.75% n-hexadecane was added at hour 16. After 20 h, the mixing speed was adjusted to 250 r·min −1 ; the pH was restored to 7.2. Air flow was regulated to 1.2 vvm throughout the experiment. The combination fermentation strategy greatly improved the molecular weight of PSA up to 498 kDa at 32 h, which is currently the maximum molecular weight of PSA produced through microbial fermentation. The yield of PSA reached 6.27 g·L −1 at the end of fermentation (36 h), which is also currently the highest yield of PSA produced by natural bacteria. Therefore, the proposed strategy could simultaneously increase the molecular weight and yield of PSA and is of great importance to the industrial production of high molecular weight PSA.
Key points
• A new fermentation process was explored to produce high molecular weight PSA.
• The yield and molecular weight were improved by the combination fermentation strategy.
• The maximum molecular weight and highest yield of PSA were obtained.
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Journal of Coatings Technology and Research
·
2022
·Vol. 19
·期 4
·1087-1100
·
IF 2.339
Liu Jing-yi,Wu Shi-zhao,Shen Zhu,Gao Jing,Hu Xin-quan,Li Guo-hua
Montmorillonite (Mnt) and organic polymer composite membrane are widely used to enhance the corrosive resistance of metal materials due to their unique properties. Herein, a uniform anticorrosion membrane coated on aluminum plate was fabricated with organic-modified nano-Mnt (OMnt) and epoxy resin (EP) as raw materials, which showed good smoothness, wear property and resistance to acidic and salty corrosion. The surface morphology, crystal phase, chemical composition, and microstructure of the OMnt/EP membrane were characterized by optical microscopy, small-angle X-ray diffraction, FTIR, SEM, and TEM, respectively. The results showed that the OMnt/EP membrane was constituted of OMnt and EP. The interplanar distance of OMnt was expanded from 1.44 to 5.36 nm. Electrochemical corrosive resistance of the membrane was tested with Tafel polarization curves and electrochemical impedance spectroscopy. The results showed that the thickness of the membrane had a positive effect on its anticorrosion performance. When its thickness was 0.18 mm, its corrosion voltage ( P corr ) increased along with its content of OMnt, while its corrosion current ( I corr ) showed increasing, decreasing and increasing trend as the content increased from 1 to 5%, from 5 to 7% and from 7 to 9%, respectively. When its content of OMnt was the same, its P corr increased along with its thickness, while its I corr decreased along with its thickness. Its maximum impedance reached 2.29 × 10 7 Ω, which was much greater than that of other EP membranes. Moreover, the corrosion resistance of the composite membranes decreased gradually as the immersion time increased, and the content of OMnt and the ratio of EP to OMnt could also affect the corrosion resistance of the membrane. These results show that the OMnt/EP composite membrane exhibits excellent anticorrosive property, which is highly promising for wide applications in industry.
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IONICS
·
2022
·Vol. 28
·期 4
·1501-1510
·
IF 2.961
Fu Yajing,Zhang Canping,Pan Lin,Yang Longyu,Wang Shiquan,Liu Jianwen
Different amounts of Fe 2 O 3 -coated NiMoO 4 /NiO composites were prepared by solvothermal method following with annealing process. The as-prepared NiMoO 4 /NiO@Fe 2 O 3 composite exhibits a reversible specific capacity of 1250 mAh g −1 after 150 cycles at a current density of 100 mA g −1 as anode for lithium-ion batteries. It exhibits efficient long-term electrochemical performance and maintains the capacity at about 750 mAh g −1 at a high current density of 500 mA g −1 after 200 cycles. The good electrochemical performance of the NiMoO 4 /NiO@Fe 2 O 3 composite may be due to its smaller size and the Fe 2 O 3 coating which can restrain its volume collapse during the charge–discharge cycle. This work could provide a promising strategy for enhancing the performance of molybdate-based composite materials for practical application in lithium-ion batteries.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 56
·84903-84915
·
IF 5.19
Zhao Shujie,Wang Yongqiang,Zhu Kaili,Zhao Dongfeng,Song Qingbin
Currently, biphasic solvents are receiving more attention for CO 2 capture due to their energy-saving potential. Whereas, most of the current biphasic solvents still suffer from high viscosity and low regeneration efficiency. To solve this problem, a novel tri-solvent biphasic solvent triethylenetetramine (TETA)-2–amino–2–methyl–1–propanol (AMP)-1-dimethylamino-2-propanol (1DMA2P) was proposed in this study, and its absorption properties, viscosity changes, desorption properties, recyclability capacity, and reaction mechanism were explored. The results showed that the CO 2 absorption load showed a trend of firstly increasing and then decreasing with the increase of AMP concentration. Although the volume of the rich phase increased with increasing AMP concentration after the absorption, it also decreases the viscosity growth. The viscosity of the solution decreased from 498 mPa•s to 91 mPa•s. During the desorption process, the maximal desorption rates of AMP-containing solvents is significantly greater than that of 2 mol/L (M) TETA + 2 M 1DMA2P (2T2D). Simultaneously, the recyclability capacity of the AMP-containing solvents were also significantly higher than that of 2T2D. The regeneration efficiency of 1.5 M TETA + 0.5 M AMP + 2 M 1DMA2P (1.5T0.5A2D) was 81.92%. It was concluded by 13 C NMR analysis that amino groups in TETA and AMP can react with CO 2 to form carbamates and carbonates. Since AMP in the biphasic solution can generate free protons through various pathways during the desorption process, it promotes the decomposition of TETA-carbamate. This process achieves the deep stripping of CO 2 in biphasic solvent. Overall, TETA-AMP-1DMA2P solution is a promising energy-saving candidate for industrial CO 2 capture due to its competitive absorption–desorption performance and low viscosity.
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MOLECULAR AND CELLULAR BIOCHEMISTRY
·
2022
·Vol. 478
·期 2
·241-247
·
IF 3.842
Zhou Quan,Cai Xu,Huang Ying,Zhou Youliang
Curcumin (CUR) is an extract of Curcuma longa Linn., which has various pharmacological activities. The instability, low water solubility and bioavailability of CUR greatly limit its clinical application. This work prepared Pluronic F127-liposome-encapsulated curcumin (CUR-LIP-F127) and explored its functional role in wound healing. Liposome-encapsulated curcumin (CUR-LIP) and CUR-LIP-F127 were prepared. Human keratinocyte cell line (HaCaT) was treated with CUR, Pluronic F127-liposome (LIP-F127) and CUR-LIP-F127, or combined with ML385 (Nrf2 inhibitor). The expression of mRNAs and proteins was detected by quantitative real-time PCR and western blotting. MTT and wound healing assays were performed to detect cell viability and migration. CUR, LIP-F127 and CUR-LIP-F127 all had no influence on cell viability of HaCaT cells. CUR-LIP-F127 treatment significantly accelerated cell migration and enhanced the expression of nuclear factor erythroid-related factor 2 (Nrf2) and kelch-like erythroid cell-derived protein 1 (Keap1) in HaCaT cells with respect to CUR or LIP-F127 treatment. ML385 treatment impaired CUR-LIP-F127-mediated promotion of migration and up-regulation of Nrf2 and Keap1 in HaCaT cells. This work demonstrated that CUR-LIP-F127 activated Nrf2/Keap1 signaling pathway to promote migration of HaCaT cells, suggesting that CUR-LIP-F127 may contribute to wound healing.
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Waste and Biomass Valorization
·
2022
·Vol. 14
·期 1
·127-144
·
IF 3.449
Mahmoud Tahany,Liu Chunzhao,Samak Nadia A.
CotA laccase was successfully expressed from Pichia pastoris . Magnetic reduced graphene oxide (MRGO) nanocomposite was synthesized and functionalized with iminodiacetic acid (IDA-NH 2 ), and then chelated with Cu 2+ for effective immobilization with His-tagged CotA laccase. The Cu 2+ -chelated MRGO (MRGO-IDA-Cu 2+ ) showed 175 mg/g-support adsorption capacity. The immobilization of CotA laccase with MRGO-IDA-Cu 2+ nano-hybrid composite was confirmed by Raman spectroscopy, Thermal Gravimetric Analysis, and X-ray diffraction. The use of nano-hybrid MRGO-IDA-Cu 2+ composite to improve heavy oil recovery was investigated. The findings revealed that the interfacial tension between oil and water was reduced to ~ 90% of its original value, and the wettability was changed from the oil-wet state [θ = ∼ 115.2 − 124.5°] to the water-wet state [θ = ∼ 8.9 − 30.1°]. The increase of immobilized CotA laccase concentration and the ratio of nano-hybrid MRGO-IDA-Cu 2+ composite decreases the value of interfacial tension (IFT) and contact angle (CA). The core-flooding studies revealed that the oil recovery process of 0.3 wt% nano-hybrid MRGO-IDA-Cu 2+ composite was enhanced by 82.8%. Graphical Abstract
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MICROCHIMICA ACTA
·
2022
·Vol. 189
·期 7
·1-10
·
IF 6.408
Sun Chenglong,Li Lu,Liu Jialin,Du Yun,Peng Yueyi,Xie Qingji
The photoelectrochemical immunoassay of glycogen phosphorylase BB (GPBB) was studied. A methyl orange/TiO 2 nanorod heterojunction was constructed on a fluorine-doped tin oxide electrode by hydrothermal synthesis, calcination, and chemical adsorption. A sandwich immune structure consisting of GPBB as the first antibody, GPBB, and a CdS@mesoporous silica-ascorbic acid (AA)–GPBB as secondary antibody composite was constructed on each of the selected well surfaces of a 96-well microplate. By adding mercaptoethylamine to structurally destroy the secondary antibody composite and release the electron donor AA, the amplification of photocurrent, and thus the “off–on” photoelectrochemical biosensing of GPBB were realized. The use of the 96-well microplate provides good reproducibility of the assembled immune structures and eliminates the possible effect of the photogenerated hole–induced protein oxidation on the photocurrent. The relevant electrodes and materials were characterized by electrochemistry, UV–vis diffuse reflectance spectra, Fourier transform infrared spectroscopy, X-ray diffractometer, scanning electron microscopy/energy dispersive spectroscopy, transmission electron microscopy and BET method. Under the optimal conditions, the photocurrent was linear with the logarithm of GPBB concentration from 0.005 to 200 ng mL −1 and with a limit of detection of 1.7 pg mL −1 ( S / N = 3). Satisfactory results were obtained in the analysis of real serum samples. Graphical abstract A sandwich immune structure consisting of GPBB first antibody, GPBB, and a CdS@mesoporous silica-ascorbic acid (AA)–GPBB secondary antibody composite was constructed on each of the selected well surfaces of a 96-well microplate. By adding mercaptoethylamine to structurally destroy the secondary antibody composite and release the electron donor AA, the amplification of photocurrent, and thus the “off–on” photoelectrochemical biosensing of GPBB were realized.
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JOURNAL OF MATERIALS RESEARCH
·
2022
·Vol. 37
·期 11
·1835-1844
·
IF 2.909
Yang Meng,Zhou Guangyan,Wei Yajuan,Huang Zhengguo,Zhang Jingbo
The catalytic activity of quaternary Cu 2 ZnSnS 4 (CZTS) as counter electrode (CE) of dye-sensitized solar cells (DSSCs) was enhanced by covering Co 9 S 8 on CZTS thin film prepared by the spin-coating method. The effect of the repeating number of spin coating process on morphologies and catalytic properties of CZTS thin films was investigated. When the repeating number of spin coating processes is 3, the CZTS thin film thickness is moderate and the formed nanoparticles are tightly bound. The conversion efficiency of DSSC based on the CZTS thin film CE prepared by 3 spin coating cycles reaches 4.79%. By forming a CZTS/Co 9 S 8 composite electrode via vulcanizing the deposited ZIF-67, the highest photoelectric conversion efficiency of DSSC based on the optimized composite CE further reaches 6.41%. The higher photoelectric conversion efficiency is attributed to the good interfacial transferring of electrons and redox properties for electrolyte of the composite CE. Graphical abstract
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ANALYTICAL SCIENCES
·
2022
·Vol. 38
·期 7
·989-1002
·
IF 1.967
Zeng Qingli,Zhong Hui,Zhang Tianci,Huang Zhiqin,Li Laisheng
A large π-conjugated perylenediimide bridged bis (β-cyclodextrin)-bonded stationary phase (PBCDP) was first prepared and characterized. The chiral HPLC performance was systematically evaluated using a series of chiral probes. The results showed that PBCDP could resolve 36 kinds of chiral compounds in reversed-phase and polar organic modes with high resolutions ( R s) 1.48–3.28 for profens, 1.25–2.85 for triazoles, 1.34–5.29 for flavanones, 1.66–4.58 for amino acids and 1.22–1.97 for β-blockers. Especially, PBCDP could completely resolve acidic non-steroidal chiral drugs (profens) and simultaneously resolve basic five triazole pesticides, which were difficult to separate by ordinary CDCSP. Compared with CDCSP (15 kinds), the new stationary phase has a wider resolution range (36 kinds). Obviously, the synergistic inclusion of the two cavities of bridged cyclodextrin, as well as the large π–π stacking, hydrogen bond, dipole–dipole and basic primary amine site (–NH–) provided by the perylenediimide bridging group contributed together to the improvement of the above chiral separations. PBCDP was a new type of versatile chiral separation material without port derivatization. Graphical abstract
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Advanced Fiber Materials
·
2022
·Vol. 4
·期 5
·1191-1208
·
IF 12.958
Zhao Chenxi,Liu Yawen,Lv Zhuochen,Cao Leitao,Ren Jing,Shao Zhengzhong,Ling Shengjie
Abstract Producing lightweight, mechanically strong, ductile, and biocompatible materials remains a significant challenge in material engineering due to the conflict between structural and mechanical features. Inspired by the “brick-and-mortar” structure of nacre, a construction with a naturally optimized structure-performance-function relationship, this study developed silk fibroin (SF) nacre as a silk protein-based nacre by integrating ice-templating and thermoplastic molding techniques. SF nacres are similar to natural nacre in microstructure, and their strength and toughness are even superior to natural nacres. These mechanical properties permit machining by extreme processing techniques, such as ion beam lithography. Furthermore, SF nacre can be used to modulate the polarization of laser beams and generate bright structural colors. Biocompatibility, mechanical robustness, good processability, and tunable coloration allow SF nacres to be used as a plastic replacement for structural engineering and biomedical use, showing promising advancement of such implantable devices towards clinical translation. Graphical Abstract
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ACTA PHARMACOLOGICA SINICA
·
2022
·Vol. 44
·期 3
·561-572
·
IF 7.169
Hong Yang,Xu Wan-qing,Feng Jing,Lou Han,Liu Heng,Wang Lei,Cui Hao,Jiang Lin-tong,Xu Ran-chen,Xu Heng-hui,Xie Min-zhen,Li Yang,Kopylov Philipp,Wang Qi,Zhang Yong
Nitidine chloride (NC) is a standard active component from the traditional Chinese medicine Zanthoxylum nitidum (Roxb.) DC. (ZN). NC has shown a variety of pharmacological activities including anti-tumor activity. As a number of anti-tumor drugs cause cardiotoxicity, herein we investigated whether NC exerted a cardiotoxic effect and the underlying mechanism. Aqueous extract of ZN (ZNE) was intraperitoneally injected into rats, while NC was injected into beagles and mice once daily for 4 weeks. Cardiac function was assessed using echocardiography. We showed that both ZNE administered in rats and NC administered in mice induced dose-dependent cardiac hypertrophy and dysfunction, whereas administration of NC at the middle and high dose caused death in Beagles. Consistently, we observed a reduction of cardiac autophagy levels in NC-treated mice and neonatal mouse cardiomyocytes. Furthermore, we demonstrated that autophagy-related 4B cysteine peptidase (ATG4B) may be a potential target of NC, since overexpression of ATG4B reversed the cardiac hypertrophy and reduced autophagy levels observed in NC-treated mice. We conclude that NC induces cardiac hypertrophy via ATG4B-mediated downregulation of autophagy in mice. Thus, this study provides guidance for the safe clinical application of ZN and the use of NC as an anti-tumor drug.
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GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
·
2022
·Vol. 261
·期 3
·735-748
·
IF 3.535
Li Zhen,Han Yu,Ji Yan,Sun Kexin,Chen Yanyi,Hu Ke
Purpose Oxidative stress and inflammation had been proved to play important role in the progression of diabetic keratopathy (DK). The excessive accumulation of AGEs and their bond to AGE receptor (RAGE) in corneas that cause the formation of oxygen radicals and the release of inflammatory cytokines, induce cell apoptosis. Our current study was aimed to evaluate the effect of ALA on AGEs accumulation as well as to study the molecular mechanism of ALA against AGE-RAGE axis mediated oxidative stress, apoptosis, and inflammation in HG-induced HCECs, so as to provide cytological basis for the treatment of DK. Methods HCECs were cultured in a variety concentration of glucose medium (5.5, 10, 25, 30, 40, and 50 mM) for 48 h. The cell proliferation was evaluated by CCK-8 assay. Apoptosis was investigated with the Annexin V- fluorescein isothiocyanate (V-FITC)/PI kit, while, the apoptotic cells were determined by flow cytometer and TUNEL cells apoptosis Kit. According to the results of cell proliferation and cell apoptosis, 25 mM glucose medium was used in the following HG experiment. The effect of ALA on HG-induced HCECs was evaluated. The HCECs were treated with 5.5 mM glucose (normal glucose group, NG group), 5.5 mM glucose + 22.5 mM mannitol (osmotic pressure control group, OP group), 25 mM glucose (high glucose group, HG group) and 25 mM glucose + ALA (HG + ALA group) for 24 and 48 h. The accumulation of intracellular AGEs was detected by ELISA kit. The RAGE, catalase (CAT), superoxide dismutase 2 (SOD2), cleaved cysteine-aspartic acid protease-3 (Cleaved caspase-3), Toll-like receptors 4 (TLR4), Nod-like receptor protein 3 (NLRP3) inflammasome, interleukin 1 beta (IL-1 ß), and interleukin 18 (IL-18) were quantified by RT-PCR, Western blotting, and Immunofluorescence, respectively. Reactive oxygen species (ROS) production was evaluated by fluorescence microscope and fluorescence microplate reader. Results When the glucose medium was higher than 25 mM, cell proliferation was significantly inhibited and apoptosis ratio was increased ( P < 0.001). In HG environment, ALA treatment alleviated the inhibition of HCECs in a dose-dependent manner, 25 μM ALA was the minimum effective dose. ALA could significantly reduce the intracellular accumulation of AGEs ( P < 0.001), activate protein and genes expression of CAT and SOD2 ( P < 0.001), and therefore inhibited ROS-induced oxidative stress and cells apoptosis. Besides, ALA could effectively down-regulate the protein and gene level of RAGE, TLR4, NLRP3, IL-1B, IL-18 ( P < 0.05), and therefore alleviated AGEs-RAGE-TLR4-NLRP3 pathway–induced inflammation in HG-induced HCECs. Conclusion Our study indicated that ALA could be a desired treatment for DK due to its potential capacity of reducing accumulation of advanced glycation end products (AGEs) and down-regulating AGE-RAGE axis–mediated oxidative stress, cell apoptosis, and inflammation in high glucose (HG)–induced human corneal epithelial cells (HCECs), which may provide cytological basis for therapeutic targets that are ultimately of clinical benefit.
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危险品化学品经营许可证（带存储）