MICROCHIMICA ACTA
·
2019
·Vol. 187
·期 1
·1-12
·
IF 5.479
Zheng Haijiao,Jia Qiong
A hybrid monolith was prepared from perovskite and cucurbit[6]uril [poly(hydroxyethyl methacrylate-pentaerythritol triacrylate) monolith] for the enrichment of phosphopeptides. By coupling with mass spectrometry, three goals were simultaneously realized, viz. (a) selective enrichment of phosphopeptides from non-phosphopeptides, (b) identification of mono- and multi-phosphopeptides, and (c) recognition of tyrosine phosphopeptides. The perovskite introduced into the monolith warrants high selectivity for phosphopeptides even at a high (10,000:1) ratio of non-phosphopeptides to phosphopeptides, and and enables identification of eight mono- and multi-phosphopeptides from standard β-casein tryptic digests. Tyrosine phosphopeptides were specifically detected via the recognition capability of cucurbit[6]uril integrated into the monolith. The method has remarkably specific enrichment capacity for phosphopeptides from samples including human serum, nonfat milk, and human acute myelocytic leukemia cell lysate.
Schematic representation of a monolith integrated with perovskite and cucurbit[6]uril. The monolithic column was coupled with mass spectrometry and applied to the enrichment of phosphopeptides. The method has remarkably specific enrichment capacity for phosphopeptides from complex biological samples.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2019
·Vol. 29
·期 6
·1285-1290
·
IF 1.913
Wen Qin,Liu Wanqiang,Zheng Yuhui,Gao Jinwei
In this study, the bio-inspired self-cracking substrate can be employed as a template to control the formation of a robust mirco-patterning film. Uniform materials with variable diameters are achieved by optimizing the egg white/water ratios and reaction temperature. The incorporated europium ions exhibit its typical f-f transitions in patterned films. Moreover, the mechanical property and excellent transmittance features have been demonstrated. The current approach can be extended to design two-dimensional nanofabrication of different materials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 12
·1-8
·
IF 5.479
Jiang Ningjing,Zhu Tingfeng,Hu Yongjun
It is known that the intensity of surface-enhanced Raman scattering (SERS) of monomeric gold nanoparticles (GNPs) is insufficient for ultrasensitive analysis. The authors describe dimeric GNPs for use in a competitive SERS and aptamer based assay for thrombin. The reagent 1,2-bis(4-pyridyl) ethylene serves as both the coupling agent and the Raman reporter on the GNP dimers. In the presence of thrombin, the hybridization of two aptamers, one attached to the GNP dimers, the other to magnetic nanoparticles, is competitively prevented. This method takes advantage of the unique “hot spots” of the GNP dimers to amplify the Raman signal. This results in an ultra-sensitive thrombin assay when compared to assays using GNP monomers. The limit of detection is as low as 1 fM of thrombin. The Raman intensity, best measured at 1612 cm −1 , increases linearly in the 1 fM to 10 nM thrombin concentration range. The method was applied to the determinaiton of thrombin in spiked simulated body fluid and human serum.
This method takes advantage of the unique “hot spots” of the gold nanoparticle dimers to amplify the Raman signal. The dimers are linked to the magnetic nanoparticles via an aptamer. The use of both competitive displacement and magnetic separation greatly improves the sensitivity of the thrombin assay.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-11
·
IF 11.878
Ma Kaijie,Zhang Yunong,Liu Le,Xi Jingyu,Qiu Xinping,Guan Tian,He Yonghong
Understanding spatial distribution difference and reaction kinetics of the electrode is vital for enhancing the electrochemical reaction efficiency. Here, we report a total internal reflection imaging sensor without background current interference to map local current distribution of the electrode in a vanadium redox flow battery during cyclic voltammetry (CV), enabling mapping of the activity and reversibility distribution with the spatial resolution of a single fiber. Three graphite felts with different activity are compared to verify its feasibility. In long-term cyclic voltammetry, the oxygen evolution reaction is proved to enhance activity distribution, and homogeneity of the electrode and its bubble kinetics with periodic fluctuation is consistent with the cyclic voltammetry curve, enabling the onset oxygen evolution/reduction potential determination. Higher activity and irreversibility distribution of the electrode is found in favor of the oxygen evolution reaction. This sensor has potential to detect in situ, among other processes, electrochemical reactions in flow batteries, water splitting, electrocatalysis and electrochemical corrosion.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Electrocatalysis
·
2019
·Vol. 11
·期 1
·59-67
·
IF 2.311
Guan Jibiao,Fang Yini,Zhang Ting,Wang Lina,Zhu Han,Du Mingliang,Zhang Ming
Biomass-derived porous carbon materials with environmental adaptability and superior specific surface area have become one of the most promising materials in 21st era, especially in the electrochemical application. Herein, we proposed a kelp-derived carbon material (KPC) with a unique highly disordered graphite layer structure as an outstanding sensor via facile KOH activation method. The BET adsorption-desorption isotherm of KPC shows a typical IUPAC I type, and KPC possesses a high specific surface area with 2064 m 2 g −1 . Morphology observation and pore size analysis indicate that its porous-rich structure comprises countless micropores and mesopores. This unique structure of KPC not only provides massive active sites but exhibits high sensitivity in the detection of heavy metal by square wave anodic stripping voltammetry (SWASV), with Pb 2+ at 53.4 μA μM −1 and Cd 2+ at 26.5 μA μM −1 in simultaneous detection. This study reports a new strategy for the detection of heavy metal ions using porous metal-free carbon materials.
✓ 已验证
产品关联
DOI
高影响因子
Stem Cell Research & Therapy
·
2019
·Vol. 10
·期 1
·1-11
·
IF 4.627
Liao Naishun,Shi Yingjun,Zhang Cuilin,Zheng Youshi,Wang Yingchao,Zhao Bixing,Zeng Yongyi,Liu Xiaolong,Liu Jingfeng
Background Adipose tissue-derived mesenchymal stem cells (ADSCs) are promising candidates for regenerative medicine. However, long-term in vitro passaging leads to stemness loss and cell senescence of ADSCs, resulting in failure of ADSC-based therapy. Methods In this study, ADSCs were treated with low dose of antioxidants (reduced glutathione and melatonin) with anti-aging and stem cell protection properties in the in vitro passaging, and the cell functions including stem cell senescence, cell migration, cell multidirectional differentiation potential, and ROS content were carefully analyzed. Results We found that GSH and melatonin could maintain ADSC cell functions through reducing cell senescence and promoting cell migration, as well as by preserving stemness and multidirectional differentiation potential, through inhibiting ROS generation during long-term expansion of ADSCs. Conclusions Our results suggested that antioxidant treatment could efficiently prevent the dysfunction and preserve cell functions of ADSCs after long-term passaging, providing a practical strategy to facilitate ADSC-based therapy.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 9
·9503-9519
·
IF 3.056
Xie Wanying,Li Ji,Sun Feiyun,Dong Wenyi
The influence of ultrasonication on membrane performance was investigated by two ultrasonication modes, direct and indirect ultrasonication as pretreatment, and simply improved PVDF-TiO 2 membranes’ performance was systematically compared. Ultrasound intensity of 100% and ultrasonication time ranged from 1 to 2 h positively affect membrane permeability. Characterization results manifested that membrane structure was eventually optimized with an even nano-TiO 2 dispersion by direct ultrasonication. Analysis of surface roughness reflected that PVDF-TiO 2 (MS-U2) surface morphological pattern was peak-valley structure that resisted fouling greatly. A good fitting of experimental result and Tansel’s simulation illustrated that anti-fouling ability was realized direct ultrasonication modified membrane. PVDF-TiO 2 (MS-U2) membrane showing the lowest | τ | reflecting the time required to reach a certain level of the fouling degree was the lowest. Relying upon modified Hermia’s model analysis, protein blockage within the membrane pore was one major fouling mechanism; surface blockage degree of PVDF-TiO 2 (MS-U2) was relative slight. Fouling mechanism analyzed by two models reflected that PVDF-TiO 2 (MS-U2) membrane exhibited a higher anti-protein fouling ability during cross-flow filtration process.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BMC PLANT BIOLOGY
·
2020
·Vol. 20
·期 1
·1-17
·
IF 3.497
Xue Cheng,Guan Si-Cong,Chen Jian-Qing,Wen Chen-Jin,Cai Jian-Fa,Chen Xu
Background Pectin methylesterase (PME) is a hydrolytic enzyme that catalyzes the demethylesterification of homogalacturonans and controls pectin reconstruction, being essential in regulation of cell wall modification. During fruit ripening stage, PME-mediated cell wall remodeling is an important process to determine fruit firmness and softening. Strawberry fruit is a soft fruit with a short postharvest life, due to a rapid loss of firm texture. Hence, preharvest improvement of strawberry fruit rigidity is a prerequisite for extension of fruit refreshing time. Although PME has been well characterized in model plants, knowledge regarding the functionality and evolutionary property of PME gene family in strawberry remain limited.Results A total of 54 PME genes (FvPMEs) were identified in woodland strawberry (Fragaria vesca ‘Hawaii 4’). Phylogeny and gene structure analysis divided these FvPME genes into four groups (Group 1–4). Duplicate events analysis suggested that tandem and dispersed duplications effectively contributed to the expansion of the PME family in strawberry. Through transcriptome analysis, we identified FvPME38 and FvPME39 as the most abundant-expressed PMEs at fruit ripening stages, and they were positively regulated by abscisic acid. Genetic manipulation of FvPME38 and FvPME39 by overexpression and RNAi-silencing significantly influences the fruit firmness, pectin content and cell wall structure, indicating a requirement of PME for strawberry fruit softening.Conclusion Our study globally analyzed strawberry pectin methylesterases by the approaches of phylogenetics, evolutionary prediction and genetic analysis. We verified the essential role of FvPME38 and FvPME39 in regulation of strawberry fruit softening process, which provided a guide for improving strawberry fruit firmness by modifying PME level.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 11
·4558-4569
·
IF 3.553
Li Tianya,Wang Kejian,Wang Jihao,Liu Yueqi,Han Yufen,Song Jinghui,Hu Hengwei,Lin Guangyi,Liu Yong
Proton exchange membrane fuel cell (PEMFC) is a promising automotive power source that has been gradually applied due to its many advantages such as pollution-free and low-temperature start-up. The gas diffusion layer (GDL) is a key component for water and gas management in PEMFC. It can directly affect the performance of PEMFC. In this paper, we prepared a new type of GDL with hierarchical pores to improve the performance of PEMFC at high current density. The new GDL mainly includes a commercial carbon paper layer and two microporous layers on the same side of carbon paper. The microporous layer near carbon paper was modified with pore former, and another layer was produced without pore former. The pore size of the middle microporous layer was controlled by the content of pore former and times of sonication. From the results of the polarization curve, electrochemical impedance spectroscopy, water contact angle, conductivity, and pore size distribution, it was found that GDL with hierarchical pores shows obvious advancement than commercial GDL. The PEMFC performance was tested to compare the new and commercial GDL. The results show that the peak power of our GDL at 100% humidity reaches 1.24 W/cm 2 and the limit current density is 3.500 A/cm 2 . The modification of the pore size of the microporous layer near the carbon paper side can improve the water management ability of the fuel cell.
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-9
·
IF 11.878
Yan Jianhua,Dong Keqi,Zhang Yuanyuan,Wang Xiao,Aboalhassan Ahmed Abdulqawy,Yu Jianyong,Ding Bin
Conductive porous carbon nanofibers are promising for environmental, energy, and catalysis applications. However, increasing their porosity and conductivity simultaneously remains challenging. Here we report chemical crosslinking electrospinning, a macro–micro dual-phase separation method, to synthesize continuous porous carbon nanofibers with ultrahigh porosity of >80% and outstanding conductivity of 980 S cm −1 . With boric acid as the crosslinking agent, poly(tetrafluoroethylene) and poly(vinyl alcohol) are crosslinked together to form water-sol webs, which are then electrospun into fibrous films. After oxidation and pyrolysis, the as-spun fibers are converted into B-F-N triply doped porous carbon nanofibers with well-controlled macro–meso–micro pores and large surface areas of ~750 m 2 g −1 . The sponge-like porous carbon nanofibers with substantially reduced mass transfer resistances exhibit multifunction in terms of gas adsorption, sewage disposal, liquid storage, supercapacitors, and batteries. The reported approach allows green synthesis of high-performance porous carbon nanofibers as a new platform material for numerous applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-6
·
IF 3.159
Zhao Yingjian,Wang Yong
Polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) have important significance for the development of next-generation rechargeable lithium-ion batteries. However, strong coordination between lithium ions and PEO chains results the ion conductivity usually lower than the expectation. In this study, sub-micron montmorillonite is incorporated into the PEO frames as Lewis base center which enables the lithium ions to escape the restraint of PEO chains. After involving montmorillonite (MMT) into the SPEs, the ionic conductivity of SPEs is 4.7 mS cm − 1 at 70 °C which shows a comparable value with that of liquid electrolyte. As coupling with LiFePO 4 material, the battery delivers a high discharge capacity of 150.3 mAh g − 1 and an excellent rate performance with a capacity of 111.8 mAh g − 1 at 0.16 C and maintains 58.2 mAh g − 1 at 0.8 C. This study suggests that the customized incorporation of Lewis base materials could offer a promising solution for achieving high-performance PEO-based solid-state electrolyte.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BMC Complementary and Alternative Medicine
·
2019
·Vol. 19
·期 1
·1-10
·
IF 2.479
Fan Yuyan,Fan Hongyu,Zhu Bin,Zhou Yilun,Liu Qingshan,Li Ping
Background Astragaloside IV (AS-IV) was reported to play a role in improving diabetic nephropathy (DN), however, the underlying mechanisms still remain unclear. The aim of the present study is to investigate whether AS-IV ameliorates DN via the regulation of endothelial nitric oxide synthase (eNOS).Methods DN model was induced in Sprague-Dawley (SD) male rats by intraperitoneal injection of 65 mg/kg streptozotocin (STZ). Rats in the AS-IV treatment group were orally gavaged with 5 mg/kg/day or 10 mg/kg/day AS-IV for eight consecutive weeks. Body weight, blood glucose, blood urea nitrogen (BUN), Serum creatinine (Scr), proteinuria and Glycosylated hemoglobin (HbA1c) levels were measured. Hematoxylin-Eosin (HE) and Periodic Acid-Schiff (PAS) staining were used to detect the renal pathology. The apoptosis status of glomerular cells was measured by TUNEL assay. The phosphorylation and acetylation of eNOS were detected by western blot. The effects of AS-IV on high-glucose (HG)-induced apoptosis and eNOS activity were also investigated in human renal glomerular endothelial cells (HRGECs) in vitro.Results Treatment with AS-IV apparently reduced DN symptoms in diabetic rats, as evidenced by reduced BUN, Scr, proteinuria, HbA1c levels and expanding mesangial matrix. AS-IV treatment also promoted the synthesis of nitric oxide (NO) in serum and renal tissues and ameliorated the phosphorylation of eNOS at Ser 1177 with decreased eNOS acetylation. Moreover, HG-induced dysfunction of HRGECs including increased cell permeability and apoptosis, impaired eNOS phosphorylation at Ser 1177, and decreased NO production, were all reversed by AS-IV treatment.Conclusion sThese novel findings suggest that AS-IV ameliorates functional abnormalities of DN through inhibiting acetylation of eNOS and activating its phosphorylation at Ser 1177. AS-IV could be served as a potential therapeutic drug for DN.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）