Journal of Analytical Science and Technology
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2021
·Vol. 12
·期 1
·1-9
·
IF 2.769
Dong Bin,Fan Qian,Li Ming,Huan Yanfu,Feng Guodong,Shan Hongyan,Fei Qiang
In this study, N-(4-aminobutyl)-N-ethylisoluminol (ABEI) was used as an energy donor, while sodium fluorescein was used as an enhancer and energy acceptor, which resulted in it producing resonance energy transfer and greatly increasing the strength of chemiluminiscence (CL). When horseradish peroxidase (HRP) is added, hydrogen peroxide (H2O2) will quickly separate into hydroxyl radicals (·OH) and superoxide ions (O2·−). If tyrosine (Tyr) is present in the system, the hydroxyl group on the benzene ring of Tyr robs ·OH and O2·− in the CL system, thereby reducing the intensity of CL. Based on this phenomenon, a luminescence system of ABEI and sodium fluorescein system was established to detect Tyr for the first time. This method has an ultra-low detection limit and a wide linear range, and is cheap and easy to operate. Under various optimal conditions, the linear range is from 3.0×10−8 to 3.0×10−5 mol/L, and the limit of detection is 2.4×10−8 mol/L. It has been successfully used in the detection of dairy products with satisfactory results.
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高影响因子
Journal of Analysis and Testing
·
2021
·Vol. 6
·期 3
·318-326
·
IF 0
Chen Ya-Shun,Feng Yu-Qi
20-Hydroxyecdysone (20E) derived from plants has a wide range of physiological and pharmacological effects on animals and humans, and rapid and sensitive methods for screening of the endogenous 20E in plants are thus required. Herein, a matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) method is described for rapid and sensitive determination of endogenous 20E in plants. It is based on the use of the (3-(acridin-9-ylamino) phenyl) boronic acid (AYPBA) as the mass tag to assist the MS and tandem MS (MS n ) analysis of 20E on MALDI-TOF/TOF MS. Good linearity was obtained with a determination coefficient ( R 2 ) larger than 0.99 in the range of 0.025–2.5 μΜ. The limit of detection (LOD) was 2.4 fmol. Acceptable precision and accuracy were gained by intra- and inter-day analysis with relative standard deviations less than 19.5% and relative recoveries ranging from 85.7 to 105.2%. In addition, the AYPBA labeled 20E produced abundant characteristic fragment ions under the high energy collision-induced dissociation, which facilitated the identification of 20E by MS 2 analysis on MALDI-TOF/TOF MS. Using the method, we enabled the identification and quantification of endogenous 20E in four herbs including Cyanotis arachoidea , Achyranthes bidentata , Spinacia oleracea and Chenopodium quinoa willd., demonstrating the feasibility of the proposed method for screening of the endogenous 20E in plants.
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Food and Bioprocess Technology
·
2021
·Vol. 14
·期 8
·1600-1610
·
IF 4.465
Wu Xia,Li Xinying,Yang Like,Yuan Lun,Xu Zhilang,Xu Jinfang,Ge Liming,Mu Changdao,Li Defu
Solid edible fat obtained by hydrogenation of vegetable oils is widely used in food market. However, the produced partially hydrogenated oils usually contain trans-fatty acids, which are harmful to health. It is meaningful to develop effective ways to directly structure edible liquid oil into gel-like state with good stability. Herein, we presented Pickering emulsions cooperatively stabilized by gelatin nanoparticles (GNPs) and dialdehyde starch nanoparticles (DASNPs) to structure liquid vegetable oils into gel state. It is interesting that Schiff’s base reactions happened between GNPs and DASNPs on the surface of Pickering emulsion droplets as well as the interface among droplets, which effectively improved the stability of Pickering emulsions. The enhanced stability of Pickering emulsions contributed to the good solidification capacity to liquid oils. As a result, the emulsions could keep structure well after 6 months of storage. Moreover, the dense interfacial layer of Pickering emulsion droplets could protect β-carotene from being diffused out of the internal phase, indicating the potential of Pickering emulsions as container for encapsulating nutrients. In sum, the developed Pickering emulsion is a good strategy to structure liquid oils.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2021
·Vol. 147
·期 6
·4047-4058
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IF 4.626
Chen Bing,Liu Yingchun,Wu Kun,Lu Maoping,Jiao Enxiang,Shi Jun,Lu Mangeng
Polymers present typically low thermal conductivity (TC) and potential fire hazards and thus restricted its application in electronics. Here, graphene oxide (GO) was employed to replace the traditional synthetic polymers. Then, the vacuum-assisted self-assembly technique was developed to prepare multifunctional flexible hybrid film based on synergistic effect of functionalized GO (PGO) and boron nitride nanosheets (BNNS). Results show that a “nacre structure” can be observed and a superior interface between matrix and fillers was constructed. Thus, the films possess high in-plane TC of 30.44 W m −1 K −1 , as well as excellent flexibility. The high TC is ascribed to constructing of the hydrogen bonding between BNNS and PGO to form a well-designed BNNS–PGO interface. Another contribution is that the dispersion of BNNS was enhanced and formed continuous TC paths. Furthermore, as-prepared hybrid films possess excellent flame retardancy and the total heat release rate and peak heat release were dropped by 75.4% and 72%, respectively, compared with original GO. Fire experiment shows that the alarm lamp and alarm buzzer connected with the hybrid film will send out the alerts within 2 s to people for taking emergency actions. This nanocomposite presents great potential applications in next-generation intelligent electronic equipment.
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高影响因子
INTERNATIONAL JOURNAL OF THERMOPHYSICS
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2021
·Vol. 42
·期 6
·1-24
·
IF 1.608
Liu Ping,Liu Zimin,Zhao Tianxiang,Liu Fei,Liao Quanlan
Densities and viscosities for the binary system of tetraethylene glycol (1) + water (2) at T = (298.15 to 323.15) K were measured as a function of composition under atmospheric pressure. The excess properties, including excess molar volumes ( \(V_{{\text{M}}}^{{\text{E}}}\) ), viscosity deviations (Δ η ), and the excess Gibbs free energy of activation for viscous flow (Δ G * E ) were calculated by using density and viscosity data, respectively. Excess properties indicated that there are hydrogen bonding interactions between tetraethylene glycol and water molecules, which are investigated in detail by FTIR and UV–Vis spectra.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2021
·Vol. 98
·期 3
·497-507
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IF 2.326
Jia Ke,Bi Zun,Liu Yunfei,Lyu Yinong
Studying electronic structure plays a key role in improving the photoluminescence (PL) properties of materials. Therefore, the electronic structure of YF 3 : x Eu 3+ with different Eu 3+ ions doping concentrations was explored by first-principles calculations based on density functional theory (DFT). As calculated, the YF 3 host had an indirect bandgap of 7.68 eV. From all calculation results we got, the band structure of YF 3 : x Eu 3+ exhibited the smallest direct band gap of 6.54 eV when the value of x was 0.10. This small direct band gap is beneficial to obtain excellent emission intensity. Besides, the morphologies and sizes have a significant influence on the fluorescence intensity of the products. A series of YF 3 : x Eu 3+ phosphors with leaf-like, spindle-like, pecan-like, and granular-like morphologies were obtained by changing the RE 3+ /NaF ratio via a microwave hydrothermal method. At the same time, the formation process of granule-like YF 3 : Eu 3+ was explored through time-dependent experiments. Furthermore, the fluorescence performance of YF 3 : x Eu 3+ was studied in detail. The as-obtained YF 3 : x Eu 3+ can exhibit orange-red emission under ultraviolet excitation because of the magnetic dipole of the 5 D 0 – 7 F 1 transition of Eu 3+ ions. After comparing the luminescence properties of samples with different morphologies, we found that the sample with granule-like morphology had the highest orange-red emission intensity. The experimental result proved that the appropriate Eu 3+ ions doping concentration were x = 0.10, which is highly consistent with the calculation result.
The great orange-red emission intensity was obtained by adjusting the electronic structure and morphology of the YF 3 : x Eu 3+ . The electronic structures of YF 3 : x Eu 3+ can be altered by changing Eu 3+ doping concentrations. The morphologies can be regulated by changing the RE 3+ /NaF ratio. Besides, the formation process of granule-like YF 3 : 0.1Eu 3+ was explored through time-dependent experiments.
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CATALYSIS LETTERS
·
2021
·Vol. 152
·期 1
·162-171
·
IF 3.186
Yang Xingyu,Li Xu,Dong Jinxiang
The epoxidation of terminal olefins (e.g., 1-octene) presents an enormous challenge owing to their electron-deficient nature, whereas the vicinal diols that are derived from epoxides are highly desirable as fine chemicals. We report the facile preparation of magnesium pyrophosphate via the thermal decomposition of commercially available newberyite and the first use of magnesium pyrophosphate as a solid catalyst for terminal olefin epoxidation. The as-synthesized magnesium pyrophosphate was characterized by XRD, FTIR, SEM–EDS, and CO 2 -TPD techniques. The CO 2 -TPD results proved that the medium base was dominant in magnesium pyrophosphate. Magnesium pyrophosphate exhibited an effective catalytic activity in the liquid-phase epoxidation of 1-octene with a 94.2% selectivity of epoxide using aqueous hydrogen peroxide as oxidant in the presence of acetonitrile solvent. The influences of various reaction parameters, including solvent, temperature, H 2 O 2 to 1-octene molar ratio, amount of magnesium pyrophosphate, reaction time, and solvent amount were investigated. According to the reaction mechanism, the perhydroxyl ion that originated from H 2 O 2 heterocracking formed in the presence of magnesium pyrophosphate and reacted with acetonitrile to generate active intermediate peroxycarboximidic acid. The epoxide and amide formed when active oxygen was transferred from peroxycarboximidic acid to the olefin. Therefore, magnesium pyrophosphate was an appropriate catalyst for 1-octene epoxidation. Graphic Abstract
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Nano Research
·
2021
·Vol. 14
·期 11
·4188-4196
·
IF 8.897
Guo Sheng-Qi,Zhang Haijun,Hu Zhenzhong,Zhen Mengmeng,Yang Bo,Shen Boxiong,Dong Fan
Semiconductor combination is one of the most common strategies to obtain high-efficiency photocatalysts; however, the effect mechanism of composition ratio on micro-structure and photocatalytic activity is remaining unclear. In this study, a case of g-C 3 N 4 quantum dots@SnS 2 (CNQD n @SnS 2 ) heterojunction with different ratio of CNQD is used to uncover the origin of optimum and excess composition for photocatalysts. Research on the functional mechanism of the optimum composition shows that 0.8 wt.% CNQD are completely attached to the non-(001) facets of SnS 2 , which benefits the formation of type-II heterojunction, resulting in an optimal pollutant degradation and mineralization efficiency. For the excess composition, both experiments and theoretical calculations confirm that excess CNQD (the part exceeding of 0.8 wt.%) located on the (001) facet of SnS 2 , leading to the type-I band alignment of this heterojunction, which severely restricts the separation of photo-induced charge carriers, and thus reduces their lifetime. This work makes the functional mechanism of composition ratio on micro-structure and photocatalytic activity clearer. Related research results provide a new insight into semiconductor combination study and take an important step toward the rational design of highly active photocatalysts.
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GLYCOCONJUGATE JOURNAL
·
2021
·Vol. 39
·期 3
·315-325
·
IF 2.916
Zeng Jiaxin,Meng Yuan,Chen Shi-Yi,Zhao Gaofeng,Wang Lianchun,Zhang En-Xin,Qiu Hong
Furin is one of the nine-member proprotein convertase family. Furin cleaves proteins with polybasic residues, which includes many viral glycoproteins such as SARS-Cov-2 spike protein. The cleavage is required for the activation of the proteins. Currently, the mechanisms that regulate Furin activity remain largely unknown. Here we demonstrated that Furin is a novel heparin/heparan sulfate binding protein by the use of biochemical and genetic assays. The K D is 9.78 nM based on the biolayer interferometry assay. Moreover, we found that sulfation degree, site-specific sulfation (N-sulfation and 3-O-sulfation), and iduronic acid are the major structural determinants for the binding. Furthermore, we found that heparin inhibits the enzymatic activity of Furin when pre-mixes heparin with either Furin or Furin substrate. We also found that the Furin binds with cells of different origin and the binding with the cells of lung origin is the strongest one. These data could advance our understanding of the working mechanism of Furin and will benefit the Furin based drug discovery such as inhibitors targeting the interaction between heparan sulfate and Furin for inhibition of viral infection.
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PubMed
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-11
·
IF 14.919
Hou Shengtai,Ma Xuefeng,Shu Yuan,Bao Jiafeng,Zhang Qiuyue,Chen Mingshu,Zhang Pengfei,Dai Sheng
The sintering of Supported Transition Metal Catalysts (STMCs) is a core issue during high temperature catalysis. Perovskite oxides as host matrix for STMCs are proven to be sintering-resistance, leading to a family of self-regenerative materials. However, none other design principles for self-regenerative catalysts were put forward since 2002, which cannot satisfy diverse catalytic processes. Herein, inspired by the principle of high entropy-stabilized structure, a concept whether entropy driving force could promote the self-regeneration process is proposed. To verify it, a high entropy cubic Zr 0.5 (NiFeCuMnCo) 0.5 O x is constructed as a host model, and interestingly in situ reversible exsolution-dissolution of supported metallic species are observed in multi redox cycles. Notably, in situ exsolved transition metals from high entropy Zr 0.5 (NiFeCuMnCo) 0.5 O x support, whose entropic contribution (TΔS config = T ⋆ 12.7 J mol −1 K −1 ) is predominant in ∆G, affording ultrahigh thermal stability in long-term CO 2 hydrogenation (400 °C, >500 h). Current theory may inspire more STWCs with excellent sintering-resistance performance.
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PubMed
高影响因子
BMC Complementary Medicine and Therapies
·
2021
·Vol. 21
·期 1
·1-12
·
IF 0
Bian Wei,Xiao Shunqiang,Yang Lei,Chen Jun,Deng Shifang
Background Quercetin and H19 can promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). However, whether quercetin regulates H19 expression to promote osteogenic differentiation of BMSCs is unclear.Methods BMSC proliferation, matrix mineralization, and alkaline phosphatase (ALP) activity were assessed using the Cell Counting Kit-8, ALP assay kit, and alizarin red staining kit, respectively. Expression of H19, miR-625-5p, BMP-2, osteocalcin, and RUNX2 were measured by qRT-PCR; β-catenin protein level was measured by western blotting.Results Quercetin promoted BMSC proliferation, enhanced ALP activity, and upregulated the expression of BMP-2, osteocalcin, and RUNX2 mRNAs, suggesting that it promoted osteogenic differentiation of BMSCs. Moreover, quercetin increased H19 expression, while the effect of quercetin on BMSCs was reversed by silencing H19 expression. Additionally, miR-625-5p, interacted with H19, was downregulated during quercetin-induced BMSC osteogenic differentiation, which negatively correlated with H19 expression. Silencing miR-625-5p expression promoted BMSC proliferation and osteogenic differentiation, whereas miR-625-5p overexpression weakened the effect of quercetin on BMSCs. Finally, quercetin treatment or downregulation of miR-625-5p expression increased β-catenin protein level in BMSCs. Upregulation or downregulation of miR-625-5p or H19 expression, respectively, inhibited β-catenin protein level in quercetin treated-BMSCs.Conclusion H19 promotes, while miR-625-5p inhibits BMSC osteogenic differentiation. Quercetin activates the Wnt/β-catenin pathway and promotes BMSC osteogenic differentiation via the H19/miR-625-5p axis.
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PubMed
CELLULOSE
·
2021
·Vol. 28
·期 17
·10827-10840
·
IF 5.044
She Qiutian,Li Jie,Lu Yudong,Lin Shan,You Ruiyun
Dialdehyde cellulose (DAC) has considerable potential as an effective metal nanoparticle support material for the preparation of highly sensitive SERS substrates. In this study, a SERS substrate based on the Tollens reaction of DAC was successfully prepared. DAC was obtained by selective oxidation of cellulose nanocrystals (CNCs) with sodium periodate (NaIO 4 ). And the aldehyde group of DAC underwent REDOX reaction with Tollens reagent to produce silver nanoparticles (Ag NPs) on the DAC in situ. The SERS "hot spots" can be generated in the gaps of Ag NPs. The as-prepared DAC-Ag NP nanocomposites showed excellent SERS activity with a highly sensitive rhodamine 6 G detection limit of 10 –9 M. In diuron detection, an excellent linear relationship ( R 2 = 0.9948) was established between the concentrations of 10 –8 M to 10 –4 M. Furthermore, the feasibility of the proposed method in the actual samples was also confirmed. The substrate was applied to detect orange and persimmon peel which were previously treated with diuron solution. The substrate has universal applicability and is expected to be further applied in the detection of other hazardous molecules. Graphic abstract
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