ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Jing Chen,Fanghong Xu,Qian Zhang,Shuying Li
Total Antioxidant Capacity (TAC) Assay plays an important role in evaluating the quality of antioxidant food and monitoring the oxidative stress level of human body. It is mainly achieved by measuring the contents of antioxidants such as AA , L-Cys and GSH, while TAC can be detected by using peroxidase-like activity of artificial nanoenzyme materials. In this work, the N-Doped, defect-rich N–MoS 2 NFs nano-materials were used to build the nano enzyme , which has strong stability and high peroxidase-like activity. H 2 O 2 was detected because it can be catalyzed to generate the intermediate ·OH and make TMB appears blue. However, when H 2 O 2 , AA, L-Cys and GSH coexist in solution, due to the oxidation resistance of AA, L-Cys and GSH, they can competitively react with ·OH in solution or reduce TMB in oxidation state (oxTMB), which reduces the characteristic absorption of oxTMB, indirectly achieves the purpose of detecting AA, L-Cys and GSH, and finally realizes the determination of TAC, even in actual serum and saliva samples. At the same time, the N–MoS 2 NFs/NH 2 -MIL-53(Al)+OPD system is further constructed. Based on the fluorescence resonance energy transfer (FRET) between NH 2 -MIL-53(Al) and oxidized OPD (oxOPD), the purpose of detecting TAC by fluorescence method was realized.
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PubMed
高影响因子
MOLECULES
·
2021
·Vol. 26
·期 11
·3108
·
IF 4.412
Mengya Jiao,Qun Dong,Yiting Zhang,Min Lin,Wan Zhou,Tao Liu,Baohong Yuan,Hui Yin
Maca (Lepidium meyenii) has emerged as a popular functional plant food because of its medicinal properties and nutritional value. Macamides, as the exclusively active ingredients found in maca, are a unique series of non-polar, long-chain fatty acidN-benzylamides with multiple bioactivities such as antifatigue characteristics and improving reproductive health. In this study, a new kind of macamide,N-benzyl eicosapentaenamide (NB-EPA), was identified from maca. We further explore its potential neuroprotective role in hypoxic–ischemic brain injury. Our findings indicated that treatment with biosynthesized NB-EPA significantly alleviates the size of cerebral infarction and improves neurobehavioral disorders after hypoxic–ischemic brain damage in neonatal mice. NB-EPA inhibited the apoptosis of neuronal cells after ischemic challenge. NB-EPA improved neuronal cell survival and proliferation through the activation of phosphorylated AKT signaling. Of note, the protective property of NB-EPA against ischemic neuronal damage was dependent on suppression of the p53–PUMA pathway. Taken together, these findings suggest that NB-EPA may represent a new neuroprotectant for newborns with hypoxic–ischemic encephalopathy.Keywords:maca;N-benzyl eicosapentaenamide;neonatal hypoxic–ischemic encephalopathy;neuroprotection;PUMA
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PubMed
高影响因子
JOURNAL OF MOLECULAR MODELING
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2021
·Vol. 27
·期 6
·1-8
·
IF 1.81
Xu Shuhong,Tan Linfeng,Liu Fan,Cui Yiping,Wang Chunlei,Zhang Rong
Optical properties of N- and F-doping triangular-shaped carbon molecules have been investigated in theory and experiment. The theoretical results showed that carbon molecules with impurity F and Cl have the same characters with pure carbon. Doping N into pure carbon molecule would change the optical rotation at 589 nm. For doping N replacing hydrogen atom structures (N-doping 1 and N-doping 2 molecules), the absorption spectra of them are similar to pure carbon molecule. However, for molecules with impurity N atom in benzene ring (N-doping 3 and N-doping 4 molecules), the peaks of wavelength of absorption spectra shift to long wavelength compared to that of pure carbon molecule. Moreover, the delocalization of molecular orbital (MO) is different from pure carbon molecule, which is caused by the impurity N changing the electrons distribution of benzene ring. We have calculated 3 without H and 4 without H molecules which are removing hydrogen atom in nitrogen atom from N-doping 3 and 4. 3 without H and 4 without H molecules have similar optical properties with pure carbon molecule. The results testified that the impurity N and F would not change the optical properties of carbon molecule if impurity did not change the delocalization of all benzene rings. Graphical abstract
Optical properties of nitrogen- and fluorine-doping carbon molecules investigating in theory and experiment.
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PubMed
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2021
·Vol. 23
·期 5
·2001252
·
IF 3.862
Dawei Zheng,Tianwei Huang,Bing Xu,Xu Zhou,Yaofeng Mao,Lin Zhong,Bing Gao,Dunju Wang
The development of 3D printing technology provides a new idea for the application of energy-containing materials as functional reactive materials, which helps Al–F high-energy materials to achieve customized performance and structure, so that energy transmit can be targeted. A high fuel-load ink (up to 90 wt%) based on Al-polytetrafluoroethylene (PTFE) is designed and fabricated using fluororubber (FR) as a binder. The content of FR is directly related to the mechanical properties of ink, and the customized structure from the uniform and stable deposition can be obtained by adjusting the content of FR (10–20 wt%). Under the display of high-speed photography, the ink shows a strong stability in combustion performance, which is conducive to realize the performance customization of the ink in the application. To better understand the combustion mechanism, the thermal properties and combustion process are analyzed in brief through thermal analysis and the combustion snapshots.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
·
IF 5.816
Chunyu Zhang,Guozhu Liu,Bo Ning,Shuairen Qian,Danning Zheng,Li Wang
The electrochemical oxygen reduction reaction (ORR) via two-electron pathway is a sustainable way of producing hydrogen peroxide. Nanostructured carbon materials are proved to be effective catalysts for 2e − ORR. Herein, a series of mesoporous carbon with tunable nitrogen species and oxygen functional groups were synthesized by varying the added amount of dopamine hydrochloride as nitrogen and oxygen source. The modified catalysts exhibited higher content of pyrrolic-N and ether C–O groups which are confirmed by a series of characterization. Raman spectra and correlation analysis revealed that the increased proportion of defect sites in carbon materials are closely related to the introduced pyrrolic-N and ether C–O groups. And the rotating ring-disk electrode (RRDE) measurement carried out in 0.1 M KOH electrolyte showed the H 2 O 2 selectivity increased with the content of defect sites. Among them, the optimized catalyst (NOC-6M) exhibited a selectivity of 95.2% and a potential of 0.71 V vs. RHE at −1 mA cm −2 . Moreover, NOC-6M possessed the high H 2 O 2 production rate of 548.8 mmol g cat −1 h −1 with faradaic efficiency of 92.4% in a two-chamber H-cell. Further mechanistic analysis revealed that the introduction of pyrrolic-N and ether C–O are likely to improve the binding energy of the defect sites toward ∗OOH intermediate, resulting in a more favorable 2e − ORR pathway for H 2 O 2 production.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Weili Teng,Qinqin Zhou,Xuekai Wang,Haibing Che,Yucheng Du,Peng Hu,Hongyi Li,Jinshu Wang
Heteroatom-doped hierarchically porous carbon is attractive electrode material for supercapacitors. However, it still remains a great challenge to develop a high-performance supercapacitor electrode with efficient preparation strategy. Herein, we report a N,O-codoped hierarchically porous carbon (NOHPC) prepared through one-step carbonization/in-situ doping/activation process by using natural diatomite as template and polydopamine as precursor. The as-prepared NOHPC possesses synergistic advantages of abundant redox-active N,O dopants, large effective specific surface area and hierarchically porous (micropores, mesopores and macropores) structure. Benefiting from such advantages, the NOHPC electrode exhibits an extremely high specific capacitance of 436.0 F g −1 at 0.625 A g −1 in H 2 SO 4 electrolyte. The as-assembled supercapacitor in H 2 SO 4 electrolyte also yields high specific capacitance (328.3 F g −1 at 0.625 A g −1 ), excellent rate performance (74.8% capacitance retention, 0.625–25 A g −1 ) and superb cycling stability (93.9%, 10,000 cycles). Besides, the corresponding device in Na 2 SO 4 electrolyte can present an enhanced energy density of 23.4 Wh kg −1 at the power density of 358.8 W kg −1 (1 A g −1 ) and still maintain 15.0 Wh kg −1 at the power density of 8357.8 W kg −1 (25 A g −1 ). The outstanding electrochemical performance and the efficient preparation process of NOHPC make it a promising widely applied electrode material for supercapacitor.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Xuan Wang,Hao Ding,Chunhong Wang,Run Zhou,Yangzi Li,Wei Li,Weihua Ao
The superhydrophobic self-cleaning coatings with reversible adhesion to water droplets have attracted much attention due to the unique and wonderful self-cleaning performance. In this paper, amorphous SiO 2 microspheres (A-SiO 2 ) and nano-TiO 2 particles (N-TiO 2 ) were used to fabricate A-SiO 2 /N-TiO 2 composites by wet grinding, and then they were modified with Hexadecyltrimethoxysilane (HDTMS) and sprayed onto the surface of substrate to obtain a A-SiO 2 /N-TiO 2 @HDTMS coating. The water contact angle (WCA) and contact angle hysteresis (CAH) of the coating were 157.2° and 2.7°, respectively. After UV irradiation, the WCA decreased to 140.9°, and water droplets stuck onto the coating surface even the coating was turned upside down. Significantly, the coating surface returned to its original superhydrophobic state after dark storage for 8 h, showing a self-healing property. Furthermore, methyl orange solution was degraded by the as-prepared coating under UV irradiation. Moreover, the as-prepared coating maintained its self-cleaning performance after being placed outdoors for 3 months, exhibiting the potential to be used outdoors for a long time. The as-prepared coating not only has excellent properties but also the advantages of environmental protection. Therefore, this research provides an advanced method to prepare self-cleaning coatings environmentally.
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高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Jun Zhao,Hanhan Wang,Hongqi Geng,Qi Yang,Yuping Tong,Weiwei He
Disturbances in the redox state of a biological system can cause diverse effects and clinical functions. The key and difficulty lies in controlling the balance between reduction and oxidation. Nanomaterials with oxidoreductase-like activity offer an appealing way to adjust anti- and pro-oxidation in response to biological conditions. To this end, we design and prepare visible light-responsive hybrid nanozymes by combining Au and N-doped carbon dots (Au/NC). It is found that Au/NC can efficiently scavenge reactive oxygen species (ROS) and free radicals and exhibit SOD-like activity, showing intrinsic antioxidant activity. Upon irradiation with visible light, we observe that Au/NC can generate ROS (e.g., hydroxyl radicals, superoxide, and singlet oxygen) and exhibit enhanced oxidase-like activity to accelerate the oxidation of chromogenic substrates, showing pro-oxidant capability. The light-activated oxidative activity is ascribed to the synergistic effects of photoexcitation of N-doped carbon dots and the surface plasmon resonance of Au nanoparticles. In addition, we demonstrate the application of the anti- and pro-oxidant capability of Au/NC in inhibition or acceleration of oxidation of Monascus pigments and Fe2+, which is switched by the incident light. These results will be of significant interest in modulating the biological redox conditions through responsive and precise nanozymes.
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高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Yiyang Lin,Kang Liu,Kejun Chen,Yan Xu,Hongmei Li,Junhua Hu,Ying-Rui Lu,Ting-Shan Chan,Xiaoqing Qiu,Junwei Fu,Min Liu
Atomically dispersed FeN4 catalysts have been considered as potential materials to replace Pt-based catalysts for the oxygen reduction reaction (ORR), but they often suffer from sluggish O2 activation kinetics due to the symmetrical charge distribution. Herein, we introduce external N, including pyrrolic-N (PN) and graphitic-N (GN), as an electron acceptor near FeN4 to regulate its charge distribution and improve its ORR activity. Theoretical calculations reveal that introduction of PN evokes much enhanced electron redistribution and local electrical field on the Fe site compared with those observed with GN introduction and the pristine one. Synchrotron X-ray absorption spectroscopy and X-ray photoelectron spectroscopy validate the positive charge accumulation of Fe in the FeN4 site induced by introducing PN. Thus, the obtained FeN4-PN exhibits a great performance for ORR in 0.1 M KOH with a remarkable half-wave potential of 0.91 V versus reversible hydrogen electrode, as well as a Tafel slope of 58 mV decade–1. This work provides a guide to improve the catalytic performances of single-atom catalysts by introducing charge-redistribution sites.
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高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Hui Ning,Dianliang Guo,Xiaoshan Wang,Zhonghao Tan,Wenhang Wang,Zhongxue Yang,Linqing Li,Qingshan Zhao,Jian Hao,Mingbo Wu
Developing of economic and efficient catalysts is critical for the application of electroreduction of carbon dioxide to highly valuable chemicals. Herein, we present a facile method to synthesize N-doped hieratically porous carbon through pyrolysis of petroleum pitch followed by ammonia etching. We found mesopores are favored formation by removing of asphaltene from petroleum pitch during the carbonation process. Simultaneously, ammonia etching can not only increase the pyridinic-N content, but also upgrade the ratio of meso- to micro- pores of carbon materials. Using the N-doped hieratically porous carbon as catalyst for carbon dioxide electroreduction, the Faradaic efficiency of carbon monoxide reaches 83% at −0.9 V vs. the reversible hydrogen electrode (RHE) in 0.1 M KHCO 3 . This superior performance is attributed to the synergistic effects of highly pyridinic-N content in conjunction with the hieratically porous architecture, rendering abundant exposed and accessible active sites for electroreduction of CO 2 . Our work provides a new strategy for the large-scale preparation of high-performance, low-cost catalysts for CO 2 electroreduction.
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高影响因子
Advanced Materials Technologies
·
2020
·Vol. 5
·期 9
·2000288
·
IF 5.969
Ruisi Chen,Junhui Tang,Yajie Yan,Ziqi Liang
Carbon nanotubes (CNTs) have been demonstrated as promising candidates for thermoelectrics (TEs) owing to their excellent electrical and mechanical properties. Here a new dopant to obtain flexible n-type CNT-based TE films from solution is reported. By doping single-walled carbon nanotubes (SWCNTs) with tetrabutylammonium bromide (TBAB), p-type nanotubes can be successfully converted to n-type form, which is confirmed by both Raman and X-ray photoemission spectroscopy (XPS) spectra. Furthermore, the influences of doping concentration and dispersion medium on TE properties are investigated. The optimal n-type SWCNT films fabricated in N , N -dimethylformamide (DMF) solvent exhibit an impressive power factor of 339 µW m −1 K −2 and excellent air stability by less than 10% variation of Seebeck coefficient during 192 h at room temperature without encapsulation, both of which are among the hitherto highest reported. This work sheds light on the interaction between TBAB molecules and SWCNTs in different dispersion media and offers a guideline for efficient n-doping of SWCNT based TE materials.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2020
·
IF 3.905
Shuang Zong,Yue Zhang,Morena S. Xaba,Xinying Liu,Aibing Chen
N-doped porous carbon nanotubes (NCNs-A) were successfully prepared by a scalable and straightforward mixed salts (NaCl/ZnCl 2 ) activation method with carbon precursor of polypyrrole (PPy). The independent salt NaCl or ZnCl 2 , the dosage of mixed salts, and the carbonization temperature all have a strong effect on the final products. ZnCl 2 is the key activator for activation, and with an increase of the mixed salts, the surface area of NCNs-A is increased. However, excess salt can lead to a decrease in the surface area. Additionally, a suitable carbonization temperature also increases the surface area. The results indicate that optimal synthesis conditions are a mixed salts mass ratio of 2 and a carbonization temperature at 800℃. During the carbonization process, the mixed salts as combined porogen and template ensure the obtained NCNs-A possesses tubular morphology derived from PPy, abundant porous architecture, a high specific surface area of 1278 m 2 g −1 and a high nitrogen doping of 9.26 at%. When used as electrode material for the supercapacitor, the NCNs-A achieved an outstanding electrochemical performance.
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高影响因子
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