CHROMATOGRAPHIA
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2019
·Vol. 83
·期 2
·305-310
·
IF 1.552
Zhang Chaozheng,Fan Longxing,Zhao Hua
Abstract An increasing number of researchers are focusing on short-chain fatty acids (SCFAs), which are closely related to various aspects of the human body. This study presented a pretreatment method for mouse feces that combined acidification and extraction. Then, a direct injection process into gas chromatography was developed. The limits of detection using this method are 0.5–0.8 mg L −1 , and the corresponding sample contents are 0.015–0.024 mg g −1 . The limits of quantification are 0.8–1.0 mg L −1 , and the corresponding sample contents are 0.024–0.030 mg g −1 . The linear relationship of the calibration curve is good and has a correlation coefficient of > 0.999. The recovery rate of the spiked standard is 80–102%. This method had been successfully applied to analysing and determining SCFAs in biological samples. Graphic Abstract
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Journal of Translational Medicine
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2019
·Vol. 17
·期 1
·1-12
·
IF 4.098
Liu Dandan,Lv Hang,Liu Qi,Sun Yanli,Hou Shenglong,Zhang Lu,Yang Mengyue,Han Baihe,wang Gang,Wang Xuedong,Du Wenjuan,Nie Honggang,Zhang Ruoxi,Huang Xingtao,Hou Jingbo,Yu Bo
Background Atherosclerosis preferentially develops in regions of disturbed flow (DF). Emerging evidence indicates that yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), which are both effectors of the Hippo pathway, sense different blood flow patterns and regulate atherosclerotic lesions. We previously found that methotrexate (MTX) reduces in-stent neoatherosclerosis, decreases the plaque burden, and has an effect on local fluid shear stress. Here, we investigated the atheroprotective effect of MTX under DF and the mechanisms underlying these properties. Methods Human umbilical vein endothelial cells (HUVECs) were subjected to biomechanical stretch using a parallel-plate flow system and treated with or without MTX at therapeutically relevant concentrations. Additionally, an extravascular device was used to induce DF in the left common carotid artery of C57BL/6 mice, followed by treatment with MTX or 0.9% saline. The artery was then assessed histopathologically after 4 weeks on a Western diet. Results We observed that MTX significantly inhibited DF-induced endothelial YAP/TAZ activation. Furthermore, it markedly decreased pro-inflammatory factor secretion and monocyte adhesion in HUVECs but had no effect on apoptosis. Mechanistically, AMPKa1 depletion attenuated these effects of MTX. Accordingly, MTX decreased DF-induced plaque formation, which was accompanied by YAP/TAZ downregulation in vivo. Conclusions Taken together, we conclude that MTX exerts protective effects via the AMP-dependent kinase (AMPK)-YAP/TAZ pathway. These results provide a basis for the prevention and treatment of atherosclerosis via the inhibition of YAP/TAZ.
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CELLULOSE
·
2019
·Vol. 27
·期 2
·743-753
·
IF 3.917
Chen Junyu,Mao Liucheng,Qi Hongxu,Xu Dazhuang,Huang Hongye,Liu Meiying,Wen Yuanqing,Deng Fengjie,Zhang Xiaoyong,Wei Yen
Abstract In recent years, cellulose nanocrystal (CNC) based materials have attracted great research attention for different applications owing to their unique properties and facile modification chemistry. In this work, CNC based thermo-responsive fluorescent composites were successfully prepared via the metal-free surface-initiated atom transfer radical polymerization (ATRP) of NIPAAm and a Schiff base containing dye (HDPAP). Results demonstrated CNC-poly (NIPAAm–HDPAP) composites display sensitive temperature-responsive coil-to-globule transition behavior at the temperature of lower critical solution temperature. The bright fluorescence offered by the Schiff base dye (HDPAP) was also confirmed by fluorescence spectra. Moreover, the preparation method of light meditated ATRP was proved to become the promising way in fabrication of multifunctional nanomaterials for its incomparable advantages, including low energy consumption, high efficiency, good monomer adaptation, free of transition metal ions. Graphic abstract
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MICROCHIMICA ACTA
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2019
·Vol. 186
·期 12
·1-10
·
IF 5.479
Gan Xiaorong,Zhao Huimin,Schirhagl Romana,Quan Xie
A non-enzymatic fluorometric assay is described for the determination of glucose. The method is based on the use of g-C 3 N 4 quantum dots (QDs) that have good water solubility. The QDs were synthesized by a one-step solvothermal process using formamide as precursor. The QDs possess an average size of ~5 nm, a band gap of 3.0~3.5 eV, and strong blue fluorescence (with excitation/emission maxima at 400/447 nm). Fluorescence is quenched by glucose (which acts as the electron acceptor) via an electron transfer mechanism. Comprehensive spectroscopy and density functional theory calculations show that the selectivity of the fluorescent probe can be attributed to the presence of N-H bonds that are formed between the QDs (mainly at plane edges) and glucose. The interaction forces lead to the formation of localized states for capturing hot electrons. This results in a decrease in the band gap and a reduction in fluorescence intensity. The probe is selective over some typical interfering species (such as cysteine and albumin) which often are present in the urine of diabetics. The method has a linear response in the 0.2 to 5.0 mM glucose concentration range and a 0.2 mM detection limit.
Schematic representation of the synthesis of g-C 3 N 4 quantum dots (QDs) as a fluorescent nanoprobe for selective detection of glucose.
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Nature Biomedical Engineering
·
2019
·Vol. 4
·期 2
·159-171
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IF 17.135
Wang Liyuan,Xie Songlin,Wang Zhiyuan,Liu Fei,Yang Yifan,Tang Chengqiang,Wu Xiaoying,Liu Peng,Li Yongjing,Saiyin Hexige,Zheng Shuang,Sun Xuemei,Xu Fan,Yu Hongbo,Peng Huisheng
Mechanical mismatches between implanted electronics and biological tissues can lead to inaccurate readings and long-term tissue damage. Here, we show that functionalized multi-walled carbon nanotubes twisted into helical fibre bundles that mimic the hierarchical structure of muscle can monitor multiple disease biomarkers in vivo. The flexible fibre bundles are injectable, have a low bending stiffness and display ultralow stress under compression. As proof-of-concept evidence of the sensing capabilities of these fibre bundles, we show that the fibre bundles enable the spatially resolved and real-time monitoring of H 2 O 2 when implanted in tumours in mice, and that they can be integrated with a wireless transmission system on an adhesive skin patch to monitor calcium ions and glucose in the venous blood of cats for 28 d. The versatility of the helical fibre bundles as chemically functionalized electrochemical sensors makes them suitable for multiple sensing applications in biomedicine and healthcare.
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SN Applied Sciences
·
2019
·Vol. 2
·期 1
·1-11
·
IF 0
Li Genrong,Yu Wenqin,Xiao Zhaojing,Long Mei,Tong Lanyan,Qiu Yue
A rapid, sensitive, and practical QuEChERS method coupled with gas chromatography–mass spectrometry was developed for the simultaneous determination of 16 chemical adjuvant residues in samples of fruits (apple, nectarine, grape) and vegetables (tomato, cucumber, spinach). All target compounds were separated in less than 16 min. Samples were extracted with acetonitrile, and the types of extraction salt and cleanup sorbent were optimized. The optimized method was validated by evaluating the linearity, accuracy, precision, and matrix effect. The recoveries of the 16 pesticides adjuvants ranged from 61.2 to 116.3% with relative standard deviations lower than 11.6%. Limits of detection ranged from 0.21 to 3.02 μg/kg, and limits of quantification ranged from 0.71 to 10.07 μg/kg. Finally, the developed method was successfully employed to identify and quantify pesticide adjuvant residues in the analysis of 30 real fruit and vegetable samples.
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CATALYSIS LETTERS
·
2019
·Vol. 150
·期 6
·1591-1604
·
IF 2.372
Du Boyu,Chen Changzhou,Sun Yang,Liu Bingyang,Yang Yingying,Gao Si,Zhang Zhenshu,Wang Xing,Zhou Jinghui
Abstract Catalytic depolymerization of lignin to produce bio-oil, liquid fuels, and aromatic chemicals in high yields is important for a biorefinery to remain competitive. In this study, undoped and Ni-doped catalysts for depolymerization of rice husk lignin (RHL) were developed and analyzed. The results showed that the catalysts had hydrotalcite-like structures with lamellar morphology. With suitable Ni-doping amount, the catalysts had high activity, thus better promoted the depolymerization of RHL. Among all catalysts, the Ni1/4MgAl catalyst could best promote the cleavage of the β-O-4 aryl ether bond in RHL molecule and thus could substantially increase the yields of bio-oil. The depolymerization catalyzed by this catalyst was also found to be temperature-, time-, and solvent-dependent. This study provides information that can be beneficial to the biorefinery industries and may help promote the valorization of lignin. Graphic Abstract
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CATALYSIS LETTERS
·
2019
·Vol. 150
·期 5
·1268-1276
·
IF 2.372
Yang Zeng-Jie,Wang Na,He Wei-Xun,Yu Yuan,Gong Qing-Tian,Yu Xiao-Qi
Lipase from porcine pancreas (PPL) is first reported to catalyze direct 1,6-conjugated addition for synthesis of triarylmethanes using p -quinonemethides ( p -QMs) and 2-naphthols. The catalytic activity of PPL was evaluated through investigating the solvent, the ratio of substrates, the enzyme loading and the temperature of the enzyme-catalyzed reactions. The present method proves to be environmentally friendly and efficient in terms of high yield, green catalyst and simple synthesis method. GraphicAbstract
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 30
·8063-8071
·
IF 3.286
Zhang Yu,Cai Yanhua,Dong Faqin,Bian Liang,Li Hua,Wang Jinhu,Du Jiayan,Qi Xiufang,He Yi
There is great interest in detection of the level of 2,4,6-trinitrotoluene (TNT) explosive due to its importance in public security and environmental protection fields. The conventional chemical sensors do not simultaneously realize simple, rapid, sensitive, selective, and direct detection of TNT in different medium without sample pretreatment. Here we present a modified wood-based chemical sensor for visual colorimetric detection of TNT in water, air, and soil. The natural wood undergoes a delignified process, which is further functionalized by 3-aminopropyltriethoxysilane (APTES). When TNT solutions are introduced, the wood-based sensor shows a colorimetric transition from light yellow to brown for naked-eye readout because of the generation of Meisenheimer complex between APTES and TNT. The photographs are collected by smartphone camera, and the RGB components are extracted to calculate the adjusted intensity for qualitative detection of TNT. This visual colorimetric sensor for TNT solution displays a linearity in the range of 0.01–5 mM with a limit of detection of 3 μM. In addition, by taking advantage of its inherent mesostructure, the wood-based sensor can be employed for visual detection of TNT vapor as well. Furthermore, it is also able to directly detect TNT in wet soil samples based on capillary action, in which TNT carried by water transports upward along the wood microchannel, triggering the generation of Meisenheimer complex.
Graphical Abstract
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EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2019
·Vol. 246
·期 1
·239-251
·
IF 2.056
Ma Pei,Wang Luyao,Xu Lei,Li Junying,Zhang Xuedian,Chen Hui
Chlorpyrifos is a type of organophosphate insecticide used extensively in the plantation of tomatoes, a worldwide popular food. However, chlorpyrifos residues on tomatoes bring risks to human health considering the consumption level of tomato is relatively high across many countries. Accurate detection and strict regulation of chlorpyrifos residues are very important in controlling health risks related to chlorpyrifos. Therefore, we developed a rapid, highly sensitive, economical, and nondestructive surface-enhanced Raman spectroscopy (SERS)-based method that can quantitatively determine the content of chlorpyrifos in tomatoes. Silver colloid was optimized and used as the enhance substrate for SERS. Chlorpyrifos residues on tomato surface and in tomato extract were both measured with SERS, and the results acquired under these practical conditions well matched those of chlorpyrifos standard solutions. Linear relationships between chlorpyrifos concentrations and SERS intensities at crucial characteristic peaks under both conditions were established, and the results showed linearity across the entire measured range from 10 −3 to 10 −9 mol L −1 . The detection limit of the proposed method was 10 −9 mol L −1 , which was much lower than the standards of chlorpyrifos use for China, Japan and EU, and was the lowest reported concentration chlorpyrifos had been measured on any fruit/vegetable surface or in its extract. The proposed method was very promising in the accurate, quantitative detection of pesticide residues, and it may be adapted to a variety of agricultural products and other areas in food science.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 412
·期 2
·439-448
·
IF 3.286
Qi Yingying,Ma Jinxin,Chen Xiandong,Xiu Fu-Rong,Chen Yiting,Lu Yongwei
Due to heavy metals’ magnified pollution from their accumulation in the ecosystem, practical detection of ultra-low concentration of heavy metals in environmental sample is of great significance for environmental supervision and maintenance of people’s health. Herein, a practical and sensitive assay of heavy metal mercury was developed by visually observing (or spectrum detecting) the change of cationic gold nanoparticles (AuNPs), which is directly caused by mercury ion induced hybridization between non-canonical base pairs. In this assay, signal probe’s response was direct rather than the indirect salt induction, thus avoiding the defect of salt-induced indirect response. It makes the analysis more sensitive. The results showed that the response of 8.2 × 10 −8 M Hg 2+ could be observed with naked eye and the detection limit of Hg 2+ in spectrometric determination was 4.9 × 10 −11 M, which is more than one order of magnitude lower than that from indirect response pattern of signal probe. In addition, high specificity of the affinity chemistry for T–Hg–T renders the assay to be highly selective. Compared with the results of cold vapor atom adsorption spectroscopy (CVAAS), this analysis has good reliability for the detection of mercury. The results fully indicate that the developed assay is an ideal alternative for online detection of heavy metal mercury in environmental pollution samples.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 11
·1-9
·
IF 5.479
Zhen Deshuai,Jiang Ning,Geng Hongchao,Qiao Yan,Liu Yu,Zhu Xingqi,Gao Chan,Grimes Craig A.,Cai Qingyun
Cobalt-doped nanoporous carbon (Co-NPC) with dodecahedral shape was pyrolytically synthesized and applied as a sorbent and matrix for the enrichment and analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). Extremely low detection limits were accomplished for cetyltrimethylammonium bromide (1 fg·mL −1 ), and Rhodamine B (1 fg·mL −1 ) in water, and Malachite Green and its metabolite in fish blood and fish extracts (pg·mL −1 concentrations).
Schematic representation of cobalt-doped nanoporous carbons (Co-NPCs) applied as SALDI matrix for analysis of toxic contaminants in fish and receipt papers. The Co-NPCs have a high desorption/ionization efficiency and low limit of detection.
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危险品化学品经营许可证（带存储）