RARE METALS
·
2020
·Vol. 40
·期 6
·1571-1577
·
IF 2.161
Zhu Meng-Ya,He Ping,Yang Xue-Li,Hui Guang-Ze,Tang Cheng-Chun,Pan Guo-Feng,Bie Li-Jian
Abstract P-xylene (p-C 8 H 10 ) is extremely harmful and dangerous to human health due to high toxicity and strong carcinogenicity. Exploring sensitive material to effectively detect p-xylene is of importance. In this paper, perovskite single crystal (C 4 H 9 NH 3 ) 2 PbI 4 has been successfully synthesized via solution method. The obtained product was analyzed by single crystal X-ray diffraction. With the space group Pbca, orthorhombic (C 4 H 9 NH 3 ) 2 PbI 4 layered perovskite structure consists of an extended two-dimensional network of corner-sharing PbI 6 octahedron. Single layer perovskite sheets of distorted PbI 6 octahedron alternated with protonated n-butylammonium cation bilayers, which offers many advantages and provides the possibility of forming a gas sensor device based on the change of resistances. Density functional theory (DFT) simulations regarding the adsorption energy revealed that this organic–inorganic hybrid perovskite compound has excellent selectivity toward p-xylene compared with other gases including C 2 H 5 OH, C 6 H 6 , CH 2 Cl 2 , HCHO, CH 3 COCH 3 and C 7 H 8 . The calculation of electron density, density of states and electron density difference showed the sensing mechanism of p-C 8 H 10 is mainly derived from physical adsorption–desorption in view of electron transfer. Graphic abstract For organic–inorganic hybrid perovskite (C 4 H 9 NH 3 ) 2 PbI 4 , single layer perovskite sheets of distorted PbI 6 octahedron alternated with protonated n-butylammonium cation bilayers (a), which offers many advantages and provides the possibility of forming a gas sensor device based on the change of resistances. Electron density difference calculation shows that adsorption of p-xylene molecule has an obvious effect on the electron distribution of (C 4 H 9 NH 3 ) 2 PbI 4 , results in electrically polarization as a local manner (b).
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CATALYSIS LETTERS
·
2020
·Vol. 151
·期 6
·1810-1820
·
IF 2.482
Zhao Nannan,Wang Songbo,Cheng Penggao,Zhang Jianping,Zhang Lei,Du Wei,Tang Na
Co 3− x Mn x O 4 is a bimetal oxide with excellent electrochemical activity in alkaline solution, has been regarded as a promising alternative in the field of ion-air batteries and proton exchange membrane fuel cell (PEMFC). Herein, we report a simple solvothermal-calcination method to fabricate Co 3− x Mn x O 4 with tunable external Co 3+ /Co 2+ and Mn 3+ /Mn 2+ ratio. The tunable ratio of element valence in the bimetal results in a higher exposure of active center for oxygen redox reaction (ORR), and thus lead to a better ORR activity, which was confirmed by X-ray photoelectron spectroscopy characterizations and electrochemical measurements. Specially, Co 1.8 Mn 1.2 O 4 with a Co 3+ /Co 2+ ratio of 2.08 showed an overpotential of 0.37 V at benchmark ORR current density of 3 mA/cm 2 in 0.1 M KOH, which is lower than that of pure oxide (Mn 3 O 4 0.53 V and Co3O4 0.56 V). In addition, the as prepared Co 1.8 Mn 1.2 O 4 exhibited a positive half-wave potential (0.83 V vs RHE) due to their more active sites, promotes charge transfer, adsorption and desorption of oxygen species. This work provides a strategy for the design and fabrication of earth-abundant, low-cost electrocatalysts for PEMFC in practical applications. Graphic Abstract Co 3− x Mn x O 4 was fabricated by tuning external Co 3+ /Co 2+ and Mn 3+ /Mn 2+ ratio, and the activity initially shows a positive correlation with the ration of Co 3+ /Co 2+ in Co 3− x Mn x O 4 .
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BIOMEDICAL MICRODEVICES
·
2020
·Vol. 22
·期 4
·1-8
·
IF 2.176
Li Xiao,Zhang Man,Hu Yujie,Xu Jian,Sun Dongke,Hu Tao,Ni Zhonghua
Rapid on-site detection of glucose has been attracting considerable attention nowadays. Screen-printed electrodes (SPEs) were assessed as ideal detection platforms due to their advantages such as, disposability, portability, ease of miniaturization, and mass production. The topology and shape of electrodes have a crucial impact on their electrical conductivity and electrochemical properties. In this study, a versatile electrochemical platform with optimized three-electrode configuration was developed through screen-printing technology. Three types of SPEs were prepared, and their electrocatalytic properties toward glucose detection were investigated. Based on this platform, both enzyme-based (denoted as GOD/rGO) and non-enzymatic (denoted as Co@MoS 2 /rGO) bioactive compounds were deposited on the working electrode of the circular SPE through simply drop-casting, respectively. Their morphology was characterized through scanning electron microscopy (SEM). Cycle sweep voltammetry was used to study the electrocatalytic activity of these biosensors. The circular SPE exhibited satisfying electrochemical redox activity and much higher sensitivity towards glucose detection, which rendered it a promising candidate for point-of-care detection.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2020
·Vol. 412
·期 30
·8339-8350
·
IF 3.637
Gao Yue,Tan Jiangkun,Lu Jiao,Sun Zhiwei,Li Zan,Ji Zhongyin,Zhang Shijuan,You Jinmao
In this study, a novel fluorescent labeling reagent 2-(9-acridone)-ethyl chloroformate (AEC-Cl) was designed, synthesized and applied for the determination of free amino acids by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The free amino acids were rapidly and efficiently labeled by AEC-Cl in the presence of basic catalyst (pH 9.0) within 5 min at room temperature (25 °C). The derivatives exhibited excellent stability and fluorescence properties, with maximum excitation and emission wavelengths at 268 nm and 438 nm, respectively. Derivatives of 22 kinds of natural amino acids were completely separated by gradient elution on a Hypersil ODS C18 column. Under the optimal conditions, the calibration curves exhibited excellent linear responses, with correlation coefficients of R 2 > 0.9994. The detection and quantification limits were in the range of 0.61–2.67 μg kg −1 and 2.07–8.35 μg kg −1 , respectively. Therefore, AEC-Cl was successfully applied for the detection of trace levels of free amino acids in honey samples.
A novel fluorescent labeling reagent was applied for the determination of free amino acids in honey by high-performance liquid chromatography with a fluorescence detector.
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ACTA PHARMACOLOGICA SINICA
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2020
·Vol. 42
·期 7
·1101-1110
·
IF 5.064
Ma Xiao-yao,Zhang Man,Fang Ge,Cheng Chuan-jing,Wang Mu-kuo,Han Yi-man,Hou Xiao-tao,Hao Er-wei,Hou Yuan-yuan,Bai Gang
Alcoholic liver disease (ALD) is one of the pathogenic factors of chronic liver disease with the highest clinical morbidity worldwide. Ursolic acid (UA), a pentacyclic terpenoid carboxylic acid, has shown many health benefits including antioxidative, anti-inflammatory, anticancer, and hepatoprotective activities. We previously found that UA was metabolized in vivo into epoxy-modified UA containing an epoxy electrophilic group and had the potential to react with nucleophilic groups. In this study we prepared an alkynyl-modified UA (AM-UA) probe for tracing and capturing the target protein of UA from liver in mice, then investigated the mode by which UA bound to its target in vivo. By conducting proteome identification and bioinformatics analysis, we identified caspase-3 (CASP3) as the primary target protein of UA associated with liver protection. Molecule docking analysis showed that the epoxy group of the UA metabolite reacted with Cys-163 of CASP3, forming a covalent bond with CASP3. The binding mode of the UA metabolites (UA, CM-UA, and EM-UA) was verified by biochemical evaluation, demonstrating that the epoxy group produced by metabolism played an important role in the inhibition of CASP3. In alcohol-treated HepG2 cells, pretreatment with the UA metabolite (10 μM) irreversibly inhibited CASP3 activities, and subsequently decreased the cleavage of PARP and cell apoptosis. Finally, pre-administration of UA (20–80 mg· kg −1 per day, ig, for 1 week) dose-dependently alleviated alcohol-induced liver injury in mice mainly via the inhibition of CASP3. In conclusion, this study demonstrates that UA is a valuable lead compound for the treatment of ALD.
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Nano Research
·
2020
·Vol. 14
·期 3
·646-653
·
IF 8.183
Jiao Handong,Jiao Shuqiang,Song Wei-Li,Xiao Xiang,She Dongmei,Li Na,Chen Haosen,Tu Jiguo,Wang Mingyong,Fang Daining
Rechargeable Al-ion batteries (AIBs) are considered as one of the most fascinating energy storage systems due to abundant Al resource and low cost. However, the cycling stability is subjected to critical problems for using Al foil as negative electrode, including Al dendrites, corrosion and pulverization. For addressing these problems, here a lightweight self-supporting N-doped carbon rod array (NCRA) is demonstrated for a long-life negative electrode in AIBs. Experimental analysis and first-principle calculations reveal the storage mechanism involving the induced deposition of N-containing function groups to Al as well as the ideal skeleton of the NCRA matrix for Al plating/stripping, which is favorable for regulating Al nucleation and suppressing dendrites growth. Compared with the Al foil, the NCRA exhibits lower areal mass density (∼ 72% of Al foil), smaller thickness (40% of Al foil), but much longer cycle life (> 4 times of Al foil). Benefiting from the remarkable stability of the array structure, symmetric cells show excellent cycling stability with small voltage hysteresis (∼ 80 mV) and meanwhile there are no corrosion and pulverization problems even after cycled for 120 hours. Besides, full cells also manifest long lifespan (1,500 cycles) and increased Coulombic efficiency (100±1%).
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 4
·966-979
·
IF 2.482
Liu Qinglong,Yang Jingchao,Luo Mingsheng,Yang Zhi,Zhao Qiuna
Abstract A series of Mn–Ti oxide catalysts were synthesized by the sol–gel method and the effects of different synthesis conditions were investigated in sequence. The microstructures and properties of the catalysts were characterized by using N 2 adsorption–desorption, XRD, SEM, H 2 -TPR, NH 3 -TPD, Raman and XPS. The catalytic performance over Mn–Ti oxide catalysts prepared under different synthesis conditions for the low-temperature SCR of NO with NH 3 were also comparatively evaluated. The results reveal that the calcination temperature and metal source play a significant role in the characteristics and the SCR activities of the catalysts. A relatively low calcination temperature is beneficial to low-temperature SCR activity. Manganese nitrate or manganese acetate as the Mn source combining with tetrabutyl titanate as Ti source can achieve high SCR activities. The excellent low-temperature NH 3 -SCR activity can be ascribed to the appropriate textural properties, amorphous Mn-oxides with equal ratio of Mn 3+ /Mn 4+ , good low-temperature reducibility and abundant surface B-acid sites. Graphic Abstract
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BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2020
·Vol. 44
·期 2
·235-246
·
IF 2.419
Guo Xiao,Guo Ailing,Li Erhu
Microbial processes are being developed to transform flavonoid glycosides to varieties of metabolites with higher bioavailability. The aim of this study was to determine the metabolic activity and survival of five lactic acid bacteria (LAB) stains ( L. rhamnosus LRa05, L. casei LC89, L. plantarum N13, L. acidophilus LA85, and L. brevis LB01) in two different citrus flavanone standards (hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside). The enzymatic activity, metabolites, antioxidant activities, and α-glucosidase inhibition property in the two standards were also investigated before and after incubated with LAB. The medium contained standards permitted survival of the five LAB stains. All strains exhibited β-glucosidase activity. Of the five LAB strains tested, just L. plantarum N13 and L. brevis LB01 have the ability to metabolize hesperetin-7-O-rutinoside, only L. plantarum N13, L. acidophilus LA85, and L. brevis LB01 could metabolize naringenin-7-O-rutinoside, moreover, L. acidophilus LA85l was the strain with the highest biotransformation ratio of naringenin-7-O-rutinoside. L. acidophilus LA85 and L. plantarum N13 can degrade naringenin-7-O-rutinoside into naringenin. L. brevis LB01 can degrade hesperetin-7-O-rutinoside into hesperetin, 3-(4′-hydroxyphenyl)-2-propenoic acid, 3-(3′-hydroxy-4′-methoxyphenyl)hydracrylic acid, and 3-(4′-hydroxyphenyl)propionic acid. Incubation of L. acidophilus LA85 in naringenin-7-O-rutinoside solution supposed no apparent influence in the biological activities that tested. L. acidophilus LA85 may potentially contribute to the bioavailability of citrus flavanones, and to be applied as functional cultures to obtain more bioavailable and bioactive metabolites in food products or in the human gastrointestinal tract.
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Nature Communications
·
2020
·Vol. 11
·期 1
·1-8
·
IF 12.121
Feng Jiaqi,Gao Hongshuai,Zheng Lirong,Chen Zhipeng,Zeng Shaojuan,Jiang Chongyang,Dong Haifeng,Liu Licheng,Zhang Suojiang,Zhang Xiangping
Developing effective catalysts based on earth abundant elements is critical for CO 2 electroreduction. However, simultaneously achieving a high Faradaic efficiency (FE) and high current density of CO ( j CO ) remains a challenge. Herein, we prepare a Mn single-atom catalyst (SAC) with a Mn-N 3 site embedded in graphitic carbon nitride. The prepared catalyst exhibits a 98.8% CO FE with a j CO of 14.0 mA cm −2 at a low overpotential of 0.44 V in aqueous electrolyte, outperforming all reported Mn SACs. Moreover, a higher j CO of 29.7 mA cm −2 is obtained in an ionic liquid electrolyte at 0.62 V overpotential. In situ X-ray absorption spectra and density functional theory calculations demonstrate that the remarkable performance of the catalyst is attributed to the Mn-N 3 site, which facilitates the formation of the key intermediate COOH * through a lowered free energy barrier.
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Scientific Reports
·
2020
·Vol. 10
·期 1
·1-11
·
IF 3.998
Dong Zijun,Chen Guanhan,Li Mu,Sun Feiyun,Jiang Chengchun,Bharti Bandna
Iodinated contrast media (ICM), which was widely used in medical imaging and was difficult to remove by conventional wastewater treatment methods, attained much attention due to its potential environmental impacts. Herein, iopamidol (IPM), one typical compound of ICM, was found to be rapidly degraded by ferrous activated persulfate oxidation (Fe(II)/PS) as compared with PS or Fe(II) alone. With a persulfate concentration of 1 mmol L −1 , n(Fe(II))/n(PS) of 1:10, and a pH of 3.0, 78% IPM was degraded within 60 min, with a degradation rate of 0.1266 min −1 . It was demonstrated that IPM degradation and deiodination were favored by a high temperature, while affected positively by acidic and neutral conditions. Radical quenching experiments and Electron Paramagnetic Resonace (EPR) spectra showed that the combined effects of SO 4 − · and · OH contributed dominantly to degrade IPM, while the · OH played an essential role during the degradation reaction. Through the Discrete Fourier Transform quantum chemical calculation, the possible reaction pathways for the oxidation of IPM by · OH are as follows: IPM-TP651-TP667-TP541-TP557, IPM-TP651-TP525-TP557, IPM-TP705-TP631-TP661, and IPM-TP705-TP735. The obtained results showed that IPM could be degraded effectively by Fe(II)/PS system, giving a promising technique for IPM removal from water.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 16
·20002-20011
·
IF 4.223
Zhu Difeng,Ping Li,Qian Renyun,Chen Chao,Hong Yawen,Tong Zhenxuan,Yang Xiaochun
Forchlorfenuron (CPPU) is often applied during the cultivation of kiwifruit to produce larger fruit. To address degradation patterns of CPPU during simulated cold chain logistics and simulated shelf life of the fruit after harvest, appropriate storage methods and safe consumption behavior can be investigated. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry method was adopted to detect CPPU residues under different conditions. CPPU in kiwifruit stored at 6 °C had a half-life of 40.8–77.0 days. However, when kiwifruit was stored at 0 °C under simulated cold chain storage conditions, the half-life of CPPU was 63.0–115.5 days, implying that lower storage temperatures can reduce the degradation rate of CPPU. The residues of CPPU in kiwifruit pulp declined with time, and the reduction followed the first-order kinetics equation. More CPPU residues were present in the pulp of postharvest kiwifruit treated with exogenous ethylene than in the pulp of untreated kiwifruit. Thus, using exogenous ethylene for artificial ripening after harvest is not recommended. We determined that the appropriate cold chain storage temperature is 6 °C. It is recommended that the public select kiwifruit stored for at least 2 weeks. The estimated chronic and acute dietary risk quotients of CPPU are ≤ 0.79% and ≤ 0.11%, respectively. Therefore, it is highly unlikely that consumers will be poisoned by CPPU due to kiwifruit consumption. Our results provide scientific evidence regarding the adoption of appropriate kiwifruit storage methods and consumption behavior to enhance consumption safety.
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Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Xie Junyao,You Xueqiu,Huang Yuqing,Ni Zurong,Wang Xinchang,Li Xingrui,Yang Chaoyong,Zhang Dechao,Chen Hong,Sun Huijun,Chen Zhong
Magnetic resonance (MR) technology has been widely employed in scientific research, clinical diagnosis and geological survey. However, the fabrication of MR radio frequency probeheads still face difficulties in integration, customization and miniaturization. Here, we utilized 3D printing and liquid metal filling techniques to fabricate integrative radio frequency probeheads for MR experiments. The 3D-printed probehead with micrometer precision generally consists of liquid metal coils, customized sample chambers and radio frequency circuit interfaces. We screened different 3D printing materials and optimized the liquid metals by incorporating metal microparticles. The 3D-printed probeheads are capable of performing both routine and nonconventional MR experiments, including in situ electrochemical analysis, in situ reaction monitoring with continues-flow paramagnetic particles and ions separation, and small-sample MR imaging. Due to the flexibility and accuracy of 3D printing techniques, we can accurately obtain complicated coil geometries at the micrometer scale, shortening the fabrication timescale and extending the application scenarios.
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