SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2026
·
IF 4.8
Leijun Xu,Yao Zhang,Jianfeng Chen,Xue Bai,Weili Mao
Excessive intake of the food additive dehydroacetic acid (DHA) poses potential risks to human health, making rapid and precise detection of its residues essential for ensuring food safety. Addressing the limitations of complex sample pretreatment and restricted sensitivity in traditional detection methods, this paper proposes a terahertz metamaterial sensor based on an asymmetric single split-ring resonator (SRR) structure. Simulation and experimental results demonstrate a distinct resonance feature near 0.411 THz, with a theoretical refractive index sensitivity of up to 105 GHz/RIU. By integrating Terahertz Time-Domain Spectroscopy (THz-TDS), trace detection of DHA was achieved over a wide concentration range of 0.02 mg/L to 1000 mg/L. To address the non-linear characteristics of the resonance frequency shift with respect to concentration, a quantitative prediction model was established using the Support Vector Regression (SVR) algorithm. The results indicate high prediction accuracy, with a coefficient of determination (R 2 ) of 0.9602 and the Normalized Root Mean Square Error (NRMSE) of 5.1% for the testing set. The experimental Limit of Detection (LOD) is as low as 0.02 mg/L, representing a sensitivity enhancement of approximately 5 × 10 5 times compared to direct THz-TDS detection. This study validates the potential of terahertz metamaterial sensing technology combined with SVR algorithms for the rapid, low-cost, and high-precision quantitative detection of food additives.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2022
·
IF 6.437
Wen-tao Li,Dong-hong Nan,Guan Zhang,Kai Li,Yan-qin Huang,Qiang Lu,Li-juan Gao,Wan-zhao Huang,Xiao-feng Han,Shan-wei Ma
The N-doped activated carbon (NAC) was prepared for bagasse (BAG) pyrolysis with 9,10-dihydroanthracene (DHA) to selectively improve production of individual 4-ethyl phenol (4-EP). Both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale apparatus were employed to conduct catalytic fast pyrolysis (CFP) experiments. The effects of N-doping modification, pyrolysis temperature, DHA/BAG ratio and NAC/BAG ratio on yield and selectivity of 4-EP were comprehensively investigated. Results indicated that the NAC exhibited excellent catalytic abilities in improving 4-EP production. About 3.03 wt % of 4-EP was obtained over NAC in the absence of DHA, whereas the 4-EP yield over activated carbon was only 2.46 wt %, indicating an increment of 23.17 % via N-doping modification. The 4-EP yield reached the maximum of 4.75 wt % with a selectivity of 25.12 % at temperature of 350 °C with a DHA/BAG ratio of 7:20 and NAC/BAG ratio of 3:1, indicating 88.45 % of 4-VP (5.37 wt %) was converted into 4-EP. Result of lab-scale tests showed that 4-EP production attained the highest value (4.02 wt %) with a selectivity of 25.53 % at temperature of 350 °C with DHA/BAG and NAC/BAG ratios of 1:5 and 1.5:1, respectively. Finally, the possible mechanism on 4-EP formation from BAG pyrolysis with co-assist of NAC and DHA was inferred.
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高影响因子
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Xiao-Man Fan,Jia-Jia Shen,Yuan-Yuan Xu,Jian Gao,Ye-Wang Zhang
A method for specific immobilization of whole-cell with covalent bonds was developed through a click reaction between alkyne and azide groups. In this approach, magnetic nanoparticle Fe 3 O 4 @SiO 2 -NH 2 -alkyne was synthesized with Fe 3 O 4 core preparation, SiO 2 coating, and alkyne functionalization on the surface. The azides were successfully integrated onto the cell surface of the recombinant E. coli harboring glycerol dehydrogenase, which was employed as the model cell. The highest immobilization yield of 83% and activity recovery of 94% were obtained under the conditions of 0.67 mg mg −1 cell-support ratio, pH 6.0, temperature 45 °C, and 20 mM Cu 2+ concentration. The immobilized cell showed good reusability, which remained over 50% of initial activity after 10 cycles of utilization. Its activity was 9.7-fold higher than that of the free cell at the condition of pH 8.0 and each optimal temperature. Furthermore, the immobilized cell showed significantly higher activity, operational stability, and reusability.
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PubMed
高影响因子
Frontiers in Aging Neuroscience
·
2020
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IF 4.364
Zhao Yueyang,Long Zhimin,Ding Ya,Jiang Tingting,Liu Jiajun,Li Yimin,Liu Yuanjie,Peng Xuehua,Wang Kejian,Feng Min,He Guiqiong
Dihydroartemisinin (DHA) is an active metabolite of sesquiterpene trioxane lactone extracted from Artemisia annua, which is used to treat malaria worldwide. DHA can activate autophagy, which is the main mechanism to remove the damaged cell components and recover the harmful or useless substances from eukaryotic cells and maintain cell viability through the autophagy lysosomal degradation system. Autophagy activation and autophagy flux correction are playing an important neuroprotective role in the central nervous system, as they accelerate the removal of toxic protein aggregates intracellularly and extracellularly to prevent neurodegenerative processes, such as Alzheimer’s disease (AD). In this study, we explored whether this mechanism can mediate the neuroprotective effect of DHA on the AD model in vitro and in vivo. Three months of DHA treatment improved the memory and cognitive impairment, reduced the deposition of amyloid β plaque, reduced the levels of Aβ40 and Aβ42, and ameliorated excessive neuron apoptosis in APP/PS1 mice brain. In addition, DHA treatment increased the level of LC3 II/I and decreased the expression of p62. After Bafilomycin A1 and Chloroquine (CQ) blocked the fusion of autophagy and lysosome, as well as the degradation of autolysosomes (ALs), DHA treatment increased the level of LC3 II/I and decreased the expression of p62. These results suggest that DHA treatment can correct autophagic flux, improve autophagy dysfunction, inhibit abnormal death of neurons, promote the clearance of amyloid-β peptide (Aβ) fibrils, and have a multi-target effect on the neuropathological process, memory and cognitive deficits of AD.
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PubMed
高影响因子
BIOORGANIC & MEDICINAL CHEMISTRY
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2021
·
IF 3.641
Zili Lei,Huijuan Wu,Yanhong Yang,Qing Hu,Yuting Lei,Wanwan Liu,Ya Nie,Lanxiang Yang,Xueying Zhang,Changyuan Yang,Ting Lin,Fengxue Tong,Jiamin Zhu,Jiao Guo
The increase of concentrations of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the serum of postmenopausal women is the important risk factor of the high morbidity of cardiovascular diseases of old women worldwide. To test the anti-hypercholesterolemia function of dihydroartemisinin (DHA) in postmenopausal women, ovariectomized (OVX) mice were generated, and DHA were administrated to OVX mice for 4 weeks. The blood and liver tissues were collected for biochemical and histological tests respectively. The mRNA and protein expression levels of genes related to metabolism and transport of cholesterol, bile acid and fatty acid in the liver or ileum were checked through qPCR and western blot . DHA could significantly reduce the high concentrations of TC and LDL-C in the serum and the lipid accumulation in the liver of ovariectomized mice. The expression of ABCG5/8 was reduced in liver of OVX mice, and DHA could up-regulate the expression of them. Genes of transport proteins for bile salt transport from blood to bile, including Slc10a1, Slco1b2 and Abcb11, were also significantly up-regulated by DHA. DHA also down-regulated the expression of Slc10a2 in the ileum of OVX mice to reduce the absorption of bile salts. Genes required for fatty acid synthesis and uptake, such as Fasn and CD36 , were reduced in the liver of OVX mice, and DHA administration could significantly up-regulate the expression of them. These results demonstrated that DHA could improve hypercholesterolemia in OVX mice through enhancing the vectorial transport of cholesterol and bile acid from blood to bile.
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PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2018
·Vol. 93
·期 8
·2351-2358
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IF 2.587
Meng-Yao Zhuang,Xiao-Ping Jiang,Xiao-Min Ling,Meng-Qiu Xu,Yi-Hao Zhu,Ye-Wang Zhang
BACKGROUND Nicotinamide cofactor-dependent oxidoreductases have been widely applied to the bioproduction of varieties of useful compounds. Efficient cofactor regeneration is often required for these oxidoreductase-catalyzed reactions. Herein, enzymatic production of 1, 3-dihydroxyacetone (DHA) via immobilized enzymes with in situ cofactor regeneration was reported. RESULTS Glycerol dehydrogenase (GDH) and NADH oxidase (Nox) were immobilized on two carriers: macroporous resin and epoxy functionalized magnetic nanoparticles (EFMN). Higher enzyme loading capacity and activity recovery were achieved on EFMN. A high immobilization yield of 90% and >70% recovery activity were obtained for both enzymes using EFMN as carriers. Besides, both immobilized enzymes showed enhanced pH stability and temperature tolerance. Co-immobilized and mixed immobilized enzymes were evaluated for synthesis of DHA, and mixed immobilized enzymes showed higher catalytic rate. The mixed reaction system also was investigated in view of various operational factors. Under the optimal conditions, a high DHA concentration with mixed immobilized enzymes system can reach up to 3.5 mmol L –1 , which was about four times higher than that without cofactor regeneration system. CONCLUSION The immobilized GDH and Nox on magnetic nanoparticles showed enhanced stabilities. A cofactor regeneration system with immobilized enzymes could be utilized for efficient production of DHA from inexpensive substrates. © 2018 Society of Chemical Industry
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高影响因子
JOURNAL OF CATALYSIS
·
2015
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IF 6.921
Xiaomei Ning,Hao Yu,Feng Peng,Hongjuan Wang
Effects of specific nitrogen functionality and oxidative functionalization of the surfaces of nitrogen-doped carbon nanotubes (NCNTs) on the interaction between Pt nanoparticles (NPs) and NCNTs have been systematically investigated. Their catalytic consequences were studied using aerobic oxidation of glycerol and electro-oxidation of CO as probing reactions. By transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD), it was revealed that nitrogen dopant obviously enhanced the dispersion of Pt NPs. Strong interaction between Pt and NCNTs was observed. Graphitic nitrogen preferentially interacted with Pt NPs, evidenced by strong electron transfer from graphitic nitrogen as electron donor to metallic Pt NPs. The oxygen-containing groups introduced by H 2 O 2 oxidation of NCNTs may reduce the donor–acceptor interaction due to the electronegativity of oxygen. By changing the nitrogen amount of NCNTs and introducing oxygen groups, the electron enrichment of Pt NPs can be tuned. Superior catalytic activity was achieved over Pt/NCNTs in the oxidation of glycerol and electro-oxidation of CO, compared with conventional carbon nanotubes as support. Moreover, for both aerobic oxidation of glycerol and electro-oxidation of CO, it was observed that the intrinsic activity depended strongly on the electron enrichment of Pt NPs, ascribed to Pt4 f 7/2 (0) binding energy from XPS, suggesting a promising approach to improving catalytic activity by maximizing the interaction between Pt NPs and graphitic nitrogen sites.
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高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Xueling Zhu,Chen Zhou,Zhicheng Pan,Jinfeng Yuan,Mingwang Pan
Waterborne polyurethane with a combination of high strength, toughness, and self-healing efficiency is attractive in many fields, but the development of such materials remains challenging due to the contradictions of these properties. In this work, a cross-linked waterborne polyurethane (DWPU) was successfully prepared by introducing a cross-linking agent containing reversible disulfide and acylhydrazone bonds on the linear backbone. The dual network of acylhydrazone covalent cross-linking and hydrogen bonding improves the stability of the polyurethane network and provides excellent mechanical properties for the elastomers, while the synergistic action of dynamic acylhydrazone bonds, disulfide bonds, and hydrogen bonds imparts outstanding self-healing performance. As a result, DWPU exhibits excellent tensile strength (49.34 MPa), exceptional Young’s modulus (305.4 MPa), satisfactory toughness (214.8 MJ m–3), and rapid self-healing efficiency (over 90%). Thanks to the abundant polar groups, DWPU presents tough adhesion strength in bonding various substrates, such as aluminum, glass fiber, and epoxy resin. In addition, it has a good transparency and inherent blue fluorescence. By integration of the self-healing ability and fluorescence properties, the self-healing process of the materials could be traced by detecting the change in fluorescence intensity of crack positions. This study not only provides a simple way for the preparation of high-performance and multifunctional environmentally friendly waterborne polymers but also broadens their application fields in optical anti-counterfeiting, protective coatings, smart devices, and so on.
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