NEURON
·
2023
·
IF 16.2
Jianzhi Zeng,Xuelin Li,Renzimo Zhang,Mingyue Lv,Yipan Wang,Ke Tan,Xiju Xia,Jinxia Wan,Miao Jing,Xiuning Zhang,Yu Li,Yang Yang,Liang Wang,Jun Chu,Yan Li,Yulong Li
Summary The coincidence between conditioned stimulus (CS) and unconditioned stimulus (US) is essential for associative learning; however, the mechanism regulating the duration of this temporal window remains unclear. Here, we found that serotonin (5-HT) bi-directionally regulates the coincidence time window of olfactory learning in Drosophila and affects synaptic plasticity of Kenyon cells (KCs) in the mushroom body (MB). Utilizing GPCR-activation-based (GRAB) neurotransmitter sensors, we found that KC-released acetylcholine (ACh) activates a serotonergic dorsal paired medial (DPM) neuron, which in turn provides inhibitory feedback to KCs. Physiological stimuli induce spatially heterogeneous 5-HT signals, which proportionally gate the intrinsic coincidence time windows of different MB compartments. Artificially reducing or increasing the DPM neuron-released 5-HT shortens or prolongs the coincidence window, respectively. In a sequential trace conditioning paradigm, this serotonergic neuromodulation helps to bridge the CS-US temporal gap. Altogether, we report a model circuitry for perceiving the temporal coincidence and determining the causal relationship between environmental events.
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PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Fei Wang,Li Li,Chaohui Yang,Zhongxing Cai,Ziyi Guo,Siyu Hou,Xiaoya Xie,Yinghao Chen,Jing Huang,Long Zhang
A series of GdPO 4 :5%Eu 3+ micro/nanomaterials with different morphologies and crystal structures were successfully prepared by the one-step solvothermal method using only the gadolinium source, the phosphoric acid source and ethanol as solvents, without any surfactants or templates, without further calcination and by adjusting only the ratio of phosphoric acid and gadolinium sources. They all have good dispersion and homogeneity. The morphology of the products was mainly regulated by the ratio of H 3 PO 4 to Gd(NO 3 ) 3 · 6H 2 O, with ratios of 2:1, 8:1, 16:1, 24:1, 32:1, 40:1 and 48:1 mL/g resulting in the formation of square, pillow, star, carambola, hollow cylinder, drum and jujube shaped GdPO 4 :5%Eu 3+ micro/nanomaterials, respectively. Ratios of 2:1–24:1 and 32:1–48:1 allow for the direct solvothermal synthesis of monoclinic and hexagonal phase gadolinium phosphate, simultaneously. In addition to their crystal structure and morphology, chemical bonding, thermal stability and specific surface area, their luminescence properties and magnetic resonance imaging (MRI) tracing properties have also been studied in comparison. Interestingly, the GdPO 4 :5%Eu 3+ micro/nanoparticles in the carambola shape had a higher photoluminescence intensity and relaxation rate of 0.7709 mM −1 s −1 (r 1 ) among all the morphologies. The possible mechanisms by which various morphologies of GdPO 4 :5%Eu 3+ were prepared in different ratios were analyzed, and the reasons for their effects on the fluorescence and MRI tracer properties were further investigated. This study is of reference significance for the simple-regulated synthesis of rare earth inorganic gadolinium-containing micro/nanomaterials and provides a reliable guarantee for the expansion of their multifunctional applications in UV–Vis luminescence and MRI tracing for implants.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 97
·期 7
·1695-1704
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IF 3.709
Bao Guo,Jidong Liu,Shixiong Tang,Yida Liu,Zenan Tian,Jianhua Lv
BACKGROUND Whether waste polyethylene terephthalate (PET) can be effectively recycled is one of the main challenges of the current environmental problems. The hydrolysis of dimethyl terephthalate (DMT) to terephthalic acid (TPA) over Nb-modified HZSM-5 zeolite was studied. Nb/HZSM-5 zeolites with different loadings were prepared and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, NH 3 -temperature programmed desorption and pyridine adsorption infrared spectroscopy. The effects of different reaction conditions on the conversion of DMT and TPA yield were investigated. RESULTS The yield of TPA strongly depends on the reaction conditions and the loading of Nb. The niobium phase exists in the form of Nb 2 O 5 on the zeolite and interacts with the surface of HZSM-5 to produce the active site of Brønsted acid. The yield of TPA is closely related to the concentration of Brønsted acid sites. On 0.6Nb/HZSM-5 catalyst, the yield of TPA is highest, at about 94%. CONCLUSION Nb/HZSM-5 catalyst has excellent catalytic activity and high stability for DMT hydrolysis. In addition, the product TPA prepared in this study can be directly applied to the current PET production supply chain, providing a promising catalytic route. © 2022 Society of Chemical Industry (SCI).
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Guangyu Xu,Fanyuan Zhang,Zhenghui Li
In this study, the solubility of 5-chloropyrazin-2-amine in four aqueous solutions (methanol, ethanol, n-propanol, and ethylene glycol (EG)) plus water was determined by a gravimetric method at temperatures ranging from T = 278.15 to 323.15 K at 101.2 kPa pressure. Experimental results indicated that 5-chloropyrazin-2-amine solubility positively increased with increasing temperature at a given solvent composition and decreased with increasing mass fraction of water in each system. The order of solubility from high to low on the mole fraction scale was as follows: methanol (0.02007, 323.15 K) > ethanol (0.01308, 323.15 K) > n-propanol (3.827 × 10–3, 323.15 K) > water (1.569 × 10–3, 323.15 K). Similarly, the solubility of 5-chloropyrazin-2-amine was higher in (methanol + water) than in the other three cosolvent mixtures. The solid phase crystal of 5-chloropyrazin-2-amine was tested by X-ray powder diffraction (XPRD) and the results showed no polymorphic transformation, solvate formation, or crystal transition during entire experiments. The experimental solubility values of 5-chloropyrazin-2-amine were correlated by three thermodynamic models. The results show that the largest relative average deviation (RAD) and root mean square deviation (RMSD) data were no more than 5.38% and 2.34 × 10–4, respectively. The Jouyban–Acree model gave the best correlation result in this study.
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Junrong Zeng,Wenhao Chen,Gaowei Zhang,Liang Yu,Liubiao Zhong,Ya Liu,Sanfei Zhao,Yejun Qiu
Affected by the slow kinetic oxygen evolution reaction (OER), the cell voltage of water splitting is usually beyond 1.5 V, causing high energy consumption to produce hydrogen. Herein, heterostructural Ni3N–NiMoN nanowires supported on carbon cloth (Ni3N–NiMoN/CC) are successfully fabricated, and they can act as bifunctional electrocatalysts, exhibiting a low overpotential of 74 mV at 100 mA cm–2 for hydrogen evolution reaction (HER) and a low potential of 1.39 V at 50 mA cm–2 for 5-hydroxymethylfurfural oxidation reaction (HMFOR), respectively. The HMFOR//HER device constructed by Ni3N–NiMoN/CC achieves a very low cell voltage of ∼1.29 V at 10 mA cm–2, which is 0.32 V lower than that of the OER//HER device. Specially, a value-added product of 2,5-furandicarboxylic acid is obtained. Additionally, density functional theory calculations are carried out. This work provides a promising strategy to further reduce the cell voltage to generate hydrogen by replacing OER with biomass oxidation.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Haoxiang Zhu,Youdi Zhang,Xusheng Guo,Youwei Cheng,Lijun Wang,Xi Li
5-Hydroxymethylfurfural (HMF) is a high-value biomass-derived platform chemical derived from renewable biomass, which is a great alternative to petroleum-based chemicals; however, it cannot be produced on a large scale at present because of the limitation of a low HMF yield and costly production. In this work, an experimental study of one-pot production of HMF from glucose in an acetone–water solvent was conducted. The effects of inorganic salts (in specific, NaCl) on miscible solvents were studied because inorganic salts could affect the phase structure of solvents. We also study the influence of the ratio between Lewis acid and Brønsted acid (L/B) on the dehydration reaction. After parameter optimization experiments, up to 64.5% HMF yield was obtained at the condition of C0 = 1.25 w/v %, CAlCl3 = 1.25 w/v %, CHCl = 10 mmol·L–1, T = 160 °C, and o/a = 80/20, and the optimized L/B was 1.25 kg·mol–1. Finally, an economic and efficient HMF production process including HMF purification and catalyst recycling was proposed; the HMF product could be produced and separated with high recovery (∼88%) and purity (∼85%) in the process. Our findings and analysis would provide support for the choice of the reaction system and bifunctional catalyst synthesis in the subsequent industrial demonstration development.
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Microbial Cell Factories
·
2022
·Vol. 21
·期 1
·1-15
·
IF 6.352
Zhang Zhen,Yu Zichen,Wang Jinduo,Yu Yifa,Li Lanxiao,Sun Pengjie,Fan Xiaoguang,Xu Qingyang
Background 5-hydroxytryptophan (5-HTP), the direct biosynthetic precursor of the neurotransmitter 5-hydroxytryptamine, has been shown to have unique efficacy in the treatment of a variety of disorders, including depression, insomnia, and chronic headaches, and is one of the most commercially valuable amino acid derivatives. However, microbial fermentation for 5-HTP production continues to face many challenges, including low titer/yield and the presence of the intermediate L-tryptophan (L-Trp), owing to the complexity and low activity of heterologous expression in prokaryotes. Therefore, there is a need to construct an efficient microbial cell factory for 5-HTP production.Results We describe the systematic modular engineering of wild-type Escherichia coli for the efficient fermentation of 5-HTP from glucose. First, a xylose-induced T7 RNA polymerase-PT7 promoter system was constructed to ensure the efficient expression of each key heterologous pathway in E. coli. Next, a new tryptophan hydroxylase mutant was used to construct an efficient tryptophan hydroxylation module, and the cofactor tetrahydrobiopterin synthesis and regeneration pathway was expressed in combination. The L-Trp synthesis module was constructed by modifying the key metabolic nodes of tryptophan biosynthesis, and the heterologous synthesis of 5-HTP was achieved. Finally, the NAD(P)H regeneration module was constructed by the moderate expression of the heterologous GDHesi pathway, which successfully reduced the surplus of the intermediate L-Trp. The final engineered strain HTP11 was able to produce 8.58 g/L 5-HTP in a 5-L bioreactor with a yield of 0.095 g/g glucose and a maximum real-time productivity of 0.48 g/L/h, the highest values reported by microbial fermentation.Conclusion In this study, we demonstrate the successful design of a cell factory for high-level 5-HTP production, combined with simple processes that have potential for use in industrial applications in the future. Thus, this study provides a reference for the production of high-value amino acid derivatives using a systematic modular engineering strategy and a basis for an efficient engineered strain development of 5-HTP high-value derivatives.
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Catalysts
·
2022
·Vol. 12
·期 8
·901
·
IF 4.501
Huaigang Su,Ze Zong,Wenjing Lou,Qin Zhao,Xiaobo Wang,Xiang Feng,Yanxing Qi,Zhaoning Song
In this study, Zr active species were implanted into a ZSM-5 zeolite framework to form a solid acid catalyst through steam treatment and the liquid-solid isomorphous substitution process. The as-synthesized Zr-ZSM-5-st catalyst ensured excellent esterification of trimethylolpropane and fatty acids (FAs) to achieve a polyol ester production yield of 94.41%. Combined with N2physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, transmission electron microscopy mapping, X-ray photoelectron spectroscopy, NH3temperature-programmed desorption, and inductively coupled mass plasma spectroscopy were conducted. The results revealed that the excellent performance of Zr-ZSM-5-st catalyst could be attributed to the enhanced acidity and the developed surface area and pore structure.Keywords:Zr-containing solid acid catalyst;ZSM-5 zeolite;polyol ester;esterification;lubricating ester oils
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yuechao Yang,Danxia Xu,Baolong Zhang,Zhimin Xue,Tiancheng Mu
Electrochemical oxidation of alcohol and aldehyde to carboxylic acids is one of the most important classes of catalytic reaction. The key point for such reactions lies in the fine tailoring the catalysts to improve the reaction and energy efficiency. For such a destination, identifying descriptors which are highly related to the catalytic efficiency is a prerequisite for designing electrocatalysts. In this work, taking 5-hydroxymethylfurfural (HMF), a biomass derived platform molecule containing alcohol and aldehyde, as the main research object, we revealed for the first time that the adsorption energy of substrate molecule is an activity descriptor for electrochemical alcohol and aldehyde oxidation. Too weak substrate adsorption is not favorable to C–H/O–H bond activation and dissociation, while too strong substrate adsorption hinders the formation of enough OH ads (an important intermediate) due to the competitive adsorption of substrate molecules and OH – at limited reaction sites. The optimal catalytic activity can be achieved by adjusting the adsorption energy of substrate molecules to make them properly adsorbed on the catalyst surface. This work not only offers a guideline for the design of advanced catalysts towards the electrochemical alcohol and aldehyde oxidation (e.g., methanol, ethanol, benzyl alcohol, glycerol, glucose, furfural and HMF) for the utilization and production of renewable resources, but also benefits the design of other electrochemical catalysts.
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Guoguang Wei,Yan Chen,Ning Zhou,Qiuhao Lu,Sheng Xu,Alei Zhang,Kequan Chen,Pingkai Ouyang
Enzyme cofactors are essential in biocatalysis for many enzymes. However, their high commercial cost limits the industrial application of cofactor-dependent enzymes. We overcame this challenge by constructing a self-sufficient biocatalyst that co-immobilised pyridoxal 5′-phosphate (PLP) and L-lysine decarboxylase (LDC) using natural polymer chitin as the functional material. First, degree of deacetylation (DDA) of chitin was regulated to enhance PLP adsorption and immobilisation. Then, the enzyme was immobilised via fusion of a chitin-binding domain. Chitin with 36% DDA efficiently co-immobilised LDC and PLP. Laser scanning confocal microscope and scanning electron microscope proved that the LDC and PLP were immobilised on the chitin. The self-sufficient biocatalyst retained over 55% of its original activity after five cycles. The proposed strategy provides a new way to achieve co-immobilisation of PLP-dependent enzymes.
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Molecular Catalysis
·
2021
·
IF 5.062
Qian Wang,Jie Zhang,Wenlong Jia,Xin Yu,Jiahong Chen,Yong Sun,Zuojun Wei,Shuliang Yang,Xing Tang,Xianhai Zeng,Lu Lin
Generally, 5-hydroxymethylfurfural (HMF) is used as feedstock to produce 2,5-furandicarboxylic acid (FDCA). Whereas, its poor stability in alkaline environment results in low yield of FDCA. By contrast, 5-[(formyloxy)methyl]furfural (FMF), a novel platform compound derived from HMF, with higher thermal and alkaline stability than HMF, is more promising to replace HMF as substrate for the production of FDCA. In this study, FMF was successfully converted into FDCA over MoCuO x by using NaClO as oxidant, undergoing 2,5-diformylfuran (DFF) and 5-hydroxymethylfuran-2-carboxylic acid (HMFCA) as intermediates. Under optimization condition (30 min, 40 °C), 100% yield of FDCA was obtained. Furthermore, it was also demonstrated that the yield of FDCA up to 90% was gained in 5 wt % FMF concentration. Higher oxygen species mobility and lattice oxygen ratio endowed MoCuO x excellent catalytic activity. The synergy of Mo and Cu species in MoCuO x ensured an efficient conversion of HMF to FDCA through synergistic redox couple of Mo 6+ /Mo 5+ and Cu 2+ /Cu + .
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JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2021
·
IF 2.262
Xueshuai Chen,Rongli Jiang,Zihan Zhou,Xingwen Wang
In this work, ZSM-5 crystals with sheet-like morphology and well-dispersion were successfully synthesized from addition of green and cheap natural polymer (gelatin). The morphology and dispersion of crystals were related to the gelatin amount added to the synthesis gel, the three-dimensional pores of polymer hydrogels can serve as microreactors for controlling zeolite growth and dispersion in a confined space. Catalytic activity for the methanol to hydrocarbons (MTH) reaction of sample synthesized by adding gelatin at a gelatin/H2O mass ratio of 2% was better than that obtained from the synthesis gel free of gelatin. Its excellent catalytic performance can be attributed to the proper acidity, well-dispersion, and sheet-like morphology.
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