Journal of Materials Chemistry A
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2020
·Vol. 8
·期 22
·11442-11447
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IF 11.301
Qinglin Liu,Yinle Li,Yanan Fan,Cheng-Yong Su,Guangqin Li
Selective hydrogenation of α,β-unsaturated aldehydes to achieve high selectivity towards a desirable product is still a great challenge mainly because of the complex conjugate system. Herein, Rh nanoclusters encapsulated in MIL-101 (Cr), synthesized by the double solvent method, are able to selectively hydrogenate CC of cinnamaldehyde, an α,β-unsaturated aldehyde and achieve over 98% selectivity with a conversion of 98% to a saturated aldehyde under mild conditions. Fourier transform infrared spectroscopy confirms that MIL-101 acts as an aldehyde protector to suppress the reactivity of CO, and the X-ray photoelectron spectroscopy (XPS) data indicate that the electropositive Rh, owing to the electron transfer from Rh to MIL-101, preferentially absorbs CC rather than CO leading to improvement of the selectivity towards saturated aldehydes. In addition, Rh@MIL-101 can also efficiently catalyse hydrodefluorination of aryl fluorides with good stability. This work provides a basic strategy to develop other selective heterogeneous catalysts via structural modulation for synergetic catalysis.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2020
·Vol. 100
·期 11
·4319-4328
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IF 2.614
Tengfei Zhan,Yunsheng Han,Chaohua Tang,Qingyu Zhao,Dandan Sun,Ying Li,Xueting Jia,Lingyun Zhou,Junmin Zhang
BACKGROUND The aim of this study was to investigate the metabolism of α -tocopherol derived from vitamin E-enriched transgenic maize (VER) and its effects on antioxidant and immune functions in broilers aged 1–42 days. A total of 360 1-day-old male broilers were randomly divided into three groups containing six replicates with 20 broilers per replicate. The negative control (NC) group and the positive control (PC) group were given non-GM maize and non-GM maize plus exogenous vitamin E (VE), respectively, and the VER group was given VER, replacing the non-GM maize given to the NC group. Between days 1 and 21 and days 22 and 42, VE levels were 4.38 and 4.63 mg kg −1 in the NC group, and 14.11 and 14.91 mg kg −1 in the PC and VER group, respectively. RESULTS The results showed that α -tocopherol from both VER and additives increased α -tocopherol transfer protein and cytochrome P450 concentrations. Serum α -tocopherol and α -tocopherylquinone levels of broilers in the PC and VER groups were also significantly higher than those in the NC group ( P < 0.05). Compared with the NC group, broilers in both groups that received α -tocopherol had reduced NF- κ B p65 concentrations, significantly decreased serum prostaglandin E 2 , interleukin-6, malondialdehyde, and hydrogen peroxide levels ( P < 0.05), and significantly increased glutathione, glutathione peroxidase, and total antioxidant capacity ( P < 0.05). CONCLUSION In summary, both VER and non-GM maize fortified with exogenous VE showed similar effects on broilers, indicating that the α -tocopherol in VER has sufficient biological activity. © 2020 Society of Chemical Industry
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Biomass Conversion and Biorefinery
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2020
·Vol. 12
·期 6
·2267-2275
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IF 2.602
Zhang Dongqiang,Chen Xiangyun,Yuan Bing,Yu Fengli,Xie Congxia,Yu Shitao
Hydration of α-pinene catalyzed by a natural deep eutectic solvent (NADES) prepared by oxalic acid dihydrate (OA·2H 2 O) and betaine (Bet), 2.7OA·2H 2 O/Bet, has been studied to develop a more economical and green process for one-step hydration method. It has been found that a homogeneous ternary DES system could be established with OA·2H 2 O and Bet in a simple, convenient, and atomic economy way. Fourier transform infrared spectrum (FT-IR), proton nuclear magnetic resonance ( 1 H NMR), thermogravimetry (TG), and differential scanning calorimetry (DSC) have been applied to confirm the formation of hydrogen bonding between OA, H 2 O, and Bet. With the consideration of catalytic activity, selectivity, and ability to recycle, 2.7OA·2H 2 O/Bet has been screened out to be a promising catalyst for hydration of α-pinene due to its appropriate acidic properties and solubility. In this catalytic system of hydration, water, as one of the reactants, both assisted in the formation of DES and acted as the dispersing agent. Correspondingly, an “emulsifying reaction at the reaction temperature and solid-liquid separation below room temperature” characteristic of this specific catalytic hydration of α-pinene has been achieved.
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MICROCHEMICAL JOURNAL
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2020
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IF 3.594
Xiuzhen Qiu,Yangyang Li,Yulin Wang,Huishi Guo,Libo Nie
α-Amanitin is the most toxic amanita identified in mushrooms, making early identification crucial for improving the human survival rates and preventing lethal poisoning cases. In this study, a novel molecular imprinting sensor based on quartz crystal microbalance (QCM) was developed for the determination of amatoxins in biological samples. To this end, allyl mercaptan was first used to attach polymerizable double bonds on the surface of QCM gold electrode. A molecularly imprinted polymer (MIP) coating was then deposited on the gold electrode surface using synthesized moieties of α-amanitin as templates and both 4-vinylpyridine and α-methacrylic acid as bi-functional monomers. The adsorption performances of the as-obtained quartz crystal microbalance molecular imprinting (QCM-MIP) sensor towards α-amatoxins were evaluated by a series of adsorption experiments. The as-prepared sensor displayed a good linear response towards α-amanitin from 1.0 ng/L to 50.0 ng/L. The sensor showed also low detection limit (0.052 pg/L), short response time (20 min), high adsorption capacity (138 μg/cm 2 ), good reproducibility, and relevant stability. Furthermore, the as-obtained QCM-MIP sensor was successful in selective recognition of α-amanitin in biological samples with recoveries ranging from 80.6% to 103.8%. Overall, the proposed QCM-MIP looks useful for the construction of future selective and quick detection of α-amanitin in biological samples.
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FOOD CHEMISTRY
·
2020
·
IF 6.306
Meiyu Zheng,Shengmin Lu,Jianrong Xing
Hesperidin hydrolysates (HHS) was produced by the hydrolysis of hesperidin (HDN) in previous studies. The potential components in HHS were identified by LC-MS, and minor components (MCS) in HHS were isolated. Antioxidant activities by radical-scavenging capacities, reducing capacity and β -carotene-linoleate assay, anti-inflammatory effects by inhibiting NO production of RAW 264.7 cells, and α-glucosidase inhibitory effects of HDN, HHS, MCS and henperetin (HTN) were investigated in present study. HHS showed higher radical scavenging activities, higher reducing capacity, and higher inhibitory activity in the β -carotene-linoleate assay than HDN. HHS inhibited the production of NO and pro-inflammatory cytokines of RAW 264.7 cells more strongly than HDN. HHS also intensively inhibited α-glucosidase activity whereas HDN showed little activity. In addition, the effects of MCS on above activities showed it play a synergistic part with HTN. This work suggested that hydrolyzation of HDN enhance the activities, and provided valuable information on effective utilization of HDN.
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MATERIALS RESEARCH BULLETIN
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2020
·
IF 4.019
Jun Liu,Lingling Sun,Guangli Li,Jue Hu,Quanguo He
In this study, spindle-like α-Fe 2 O 3 mesocrystals/reduced-graphene-oxide composites modified glassy carbon electrode (α-Fe 2 O 3 /rGO/GCE) is developed for ultrasensitive electrochemical detection of DA. Morphologies and crystal structures of this composite are characterized by SEM, TEM , XRD , Raman spectrum, and XPS , respectively. The electrochemical behavior of DA on these electrodes are investigated by CV and EIS . The electrochemical conditions are optimized systematically. As results, the oxidation current of DA on α-Fe 2 O 3 /rGO/GCE is 38.13-fold increase than that on bare GCE. It is ascribed to the high catalytic activity of α-Fe 2 O 3 mesocrystals and large electrochemical active area of rGO. Under the best voltammetric condition, wide linear detection range (from 1.0×10 −8 to 9.0×10 -4 mol/L) and low LOD of 3.26 nM (S/N=3) are obtained on the α-Fe 2 O 3 /rGO/GCE. Furthermore, this electrode is also used for DA detection in real human serums samples successfully. This α-Fe 2 O 3 /rGO/GCE provides a good example in design of other mesocrystals-based composite materials for electrochemical detection.
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MICROCHIMICA ACTA
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2020
·Vol. 187
·期 9
·1-9
·
IF 6.232
Hu Xuemei,Wei Zixuan,Tang Menghuan,Long Yijuan,Zheng Huzhi
Lowering the background signal for more sensitive analysis of determinands is as important as amplifying the target signal. The photoinduced oxidase of fluorescein has been reported, which can catalyze the oxidization of common substrates in a few minutes. As a metaphor for locks and keys, we designed double locks confining the activity of fluorescein to reduce the background absorbance during colorimetric detection. The first lock inhibits the main activity of fluorescein by phosphating. The second lock almost completely deactivates fluorescein by forming coordination nanoparticles (CNPs) via the self-assembly of cerium chloride and fluorescein diphosphate (FDP). The Ce-FDP CNPs are characterized by scanning electron microscope (SEM), dynamic light scattering (DLS), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectrum (EDS), which show electrostatic formation and amorphous character in the morphology. Alkaline phosphatase (ALP), the key to release fluorescein, can destroy Ce-FDP CNPs along with decomposing FDP by degrading phosphate groups. Therefore, a novel colorimetric strategy for sensitive detection of ALP is established. The detection of α-fetoprotein (AFP) is further succeeded by labeling AFP antibody with ALP. By dramatically reducing the background absorbance, the detection limits of ALP and AFP are as low as 0.014 mU/mL and 0.023 ng/mL, respectively. This convenient, brief, sensitive assay provides a promising prospect for clinical diagnosis.
Graphical abstract
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PULMONARY PHARMACOLOGY & THERAPEUTICS
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2020
·
IF 2.681
Min Chen,Cuifen Chen,Yun Gao,Dongming Li,Dan Huang,Ziyu Chen,Xuanna Zhao,Qiu Huang,Dong Wu,Tianwen Lai,Guomei Su,Bin Wu,Beixian Zhou
Background Bergenin , a type of polyphenol compound, exhibits antiulcerogenic, anti-inflammatory, antitussive , and burn wound-healing properties. However, its therapeutic effect on tumor necrosis factor α (TNF-α)-induced proinflammatory responses in the airway and potential mechanisms of actions are still unclear. This study aimed to investigate the anti-inflammatory effects and mechanism of bergenin in TNF-α-stimulated human bronchial epithelial (16-HBE) cells. Methods Cell Counting Kit-8 was used to evaluate cytotoxicity. Cytokine expression was analyzed by reverse transcription-quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay. Immunofluorescence, western blot , and sirtuin-1 (SIRT1) activity assays were employed to investigate potential molecular mechanisms. Results Bergenin obviously decreased both mRNA and protein expression levels of interleukins 6 and 8 (IL-6 and IL-8) in TNF-α-stimulated 16-HBE cells. Bergenin blocked TNF-α-mediated activation of nuclear factor κB (NF-κB) signaling and NF-κB nuclear translocation. Interestingly, RT-qPCR and western blotting results revealed that bergenin did not affect SIRT1 expression, but significantly increased its activity. Bergenin-mediated SIRT1 activation was further confirmed by results indicating decreased acetylation levels of NF-κB-p65 and p53. Moreover, the inhibitory effects of bergenin on mRNA and protein expression levels of IL-6 and IL-8 were reversed by a SIRT1 inhibitor. In addition, combining bergenin and dexamethasone (DEX) yielded additive effects on the reduction of IL-6 and IL-8 expression. Conclusions These findings demonstrate that bergenin could suppress TNF-α-induced proinflammatory responses by augmenting SIRT1 activity to block the NF-κB signaling pathway , which may provide beneficial effects for the treatment of airway inflammation associated with asthma.
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POLYMER DEGRADATION AND STABILITY
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2019
·
IF 3.78
Yong Luo,Delong Xie,Yifan Chen,Tao Han,Renjie Chen,Xinxin Sheng,Yi Mei
To overcome the flammability and melt dripping issues of poly(vinyl alcohol) (PVA) aerogel , a combination of ammonium polyphosphate (APP) and α-zirconium phosphate (α-ZrP) was used to enhance the flame retardancy of PVA aerogels, which were fabricated using a simple mixing and freeze-drying approach. Results obtained from transmission electron microscopy (TEM) and atomic force microscopy (AFM) confirm that α-ZrP was successfully exfoliated by ultrasonic stripping. The effects of the exfoliated α-ZrP nano-plates on the microstructure, composition , flame retardancy, fire behavior of the aerogels was investigated using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimetry test. It was found that the incorporation of α-ZrP improved the 3D network structure of the PVA aerogel. The results showed that a sample with 2 wt% α-ZrP and 13 wt% APP could reach the maximal LOI value of 43.1%, achieved the UL-94 V-0 rating, and the peak heat release rate (PHRR) and total heat release (THR) of the sample reduced by 82.6% and 76.3%, respectively. Thermogravimetric analysis (TGA) revealed that α-ZrP improved the thermal stability of PVA-APP system. The residues analysis revealed that α-ZrP accelerated the formation of a compact and graphitization structure of residues and catalyzed the charring of PVA during burning.
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NANOTECHNOLOGY
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2019
·Vol. 31
·期 10
·105707
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IF 3.399
Zijian Chen,Ting Guo,Zhuangzhi Wu,Dezhi Wang
As highly efficient non-precious metal-based catalysts for the hydrogen evolution reaction (HER), molybdenum carbides have attracted much attention over the phase and structure modification for the improvement of HER performances. In this work, a novel strategy is proposed to modulate phases of molybdenum carbides by boron doping, so that the HER performances can be well controlled. After B-doping, the HER activity of the as-prepared B30 catalyst is significantly enhanced with a much smaller Tafel slope of 78 mV dec−1 than that of the blank one (134 mV dec−1), which originates from the increased amount of active sites, enhanced turnover frequency of each active site and reduced electron transfer resistance. Moreover, this work could broaden our view of phase regulation and provide more possible perspectives for the application in other fields.
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POLYMER
·
2019
·
IF 3.771
Manoj B. Kale,Nidhin Divakaran,Suhail Mubarak,Duraisami Dhamodharan,T. Senthil,Lixin Wu
The in situ polymerization scheme was chose to introduce the amine intercalated α-zirconium phosphate (fZrP) in the waterborne polyurethane (WPU). The α-ZrP (ZrP) was prepared by refluxing zirconyl chloride octahydrate and then amine intercalated using ethylenediamine . The nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy , X-ray photoelectron spectroscopy and thermogravimetric analysis . The fZrP was introduced in the WPU with the known filler content of 0.1, 0.5 and 1 wt%, respectively. The prepared WPU/fZrP nanocomposites films have shown better mechanical, thermal and water resistance properties compared to the neat WPU and unmodified ZrP nanocomposites. The tensile strength of WPU filled with 1 wt% fZrP was increased by 57.09% against the WPU filled with 1 wt% unmodified ZrP. The thermal properties of the WPU showed increasing performance with the increasing fZrP content. The incorporation of fZrP in the WPU increased the thermal conductivity from 0.1777 W/m . K for virgin WPU and 0.2969 W/m . K for WPU/fZrP (1 wt%). The water resistance performance of the WPU was also improved with the increasing filler content. The results portray that the α-ZrP nanoplates can be an additive material to improve the thermo-mechanical performance of polymers.
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DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 44
·16626-16632
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IF 4.052
Haonan Liu,Hongping Wu,Hongwei Yu,Zhanggui Hu,Yicheng Wu
New polymorphous phases, α- and β-LiMoPO6, have been successfully synthesized by the high temperature solution technique and their structures have been determined by single crystal X-ray diffraction. α-LiMoPO6 crystallizes in the orthorhombic space group Pbcn (No. 60) with a = 12.1141(4) Å, b = 8.9251(3) Å and c = 8.7389(3) Å, while β-LiMoPO6 crystallizes in the monoclinic space group P21/c (No. 14) with a = 6.3441(3) Å, b = 7.5949(3) Å, c = 9.3430(4) Å and β = 94.546(4)°. Both structures exhibit a similar three-dimensional (3D) framework composed of MoO6 octahedra and PO4 tetrahedra. Interestingly, an anomalous phase transition, i.e. the high-temperature β-LiMoPO6 phase exhibiting larger density than the low-temperature α-LiMoPO6, has been observed. Detailed structural analyses show that the anomalous phase transition mainly originates from the ‘straightened’ effect of the zigzag [MoO3O3PO]∞ chains in their structures. Furthermore, the optical and thermal properties of two compounds are also reported.
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