RSC Advances
·
2015
·Vol. 5
·期 84
·68369-68377
·
IF 3.84
Mingyong Du,Caili Dai,Ang Chen,Xuepeng Wu,Yuyang Li,Yifei Liu,Weitao Li,Mingwei Zhao
A novel fluid system composed of 2-methoxycinnamic acid (trans-OMCA) and 1-hexadecyl-3-methylimidazolium bromide (C16mimBr) in an aqueous solution was investigated. The compounds trans-OMCA and C16mimBr in an aqueous solution can self-assemble and form viscoelastic worm-like micelles. The concentrations of trans-OMCA and C16mimBr have a significant influence on the rheological properties of the system. The samples were characterized by rheological measurements. The structural isomerization of trans-to-cis for trans-OMCA occurred after UV light irradiation. The transformation of the system after UV light irradiation was determined by UV-vis absorption spectroscopy, rheological measurement and cryo-TEM observation. Surface tension measurements were carried out to investigate the role of trans-OMCA and UV light in C16mimBr aqueous solution. Critical aggregation concentration (cac), effectiveness of surface tension reduction (Πcac), maximum excess surface concentration (Γmax) and minimum area occupied per surfactant molecule (as) were investigated. Critical packing parameter was introduced to express the mechanism of aggregation behavior transition.
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ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Youqin Lu,Xilin Wang,Min Wang,Lingqian Kong,Jinsheng Zhao
This paper reports the synthesis and characterization of two none-noble oxygen reduction reaction (ORR) catalysts including the CuPPyPhen/C and the FePPyPhen/C. The catalysts were prepared by covalently bonding of the 1,10-phenanthroline metal complexes with the poly(pyrrole-3-carboxylic acid)/C composite, which was prepared with an oxidative chemical method of polymerization of pyrrole-3-carboxylic acid on the carbon surface. Both catalysts were characterized using electrochemical techniques such as cyclic voltammetry (CV), rotating disk electrode (RDE), as well as rotating ring disk electrode (RRDE) to quantitatively obtain ORR kinetic constants and the reaction mechanisms. The results of the data showed that both catalysts underwent a predominant four-electron pathway for the reduction of oxygen, with the CuPPyPhen/C catalyst exhibited a better ORR activity and stability than that of the FePPyPhen/C and PPyPhen/C catalyst, suggesting that the ORR activity of the catalyst depend on the species of the metal ions which plays a key role to enhance the eletrocatalytic activity and accelerate the step for ORR. The physical morphologies and the surface chemical compositions of the catalysts were examined by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively.
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MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 1
·185-192
·
IF 3.719
Wang Huiqi,Feng Wei,Jia Qiong
We show that graphene oxide functionalized with 3-aminophenylboronic acid represents a useful new adsorbent for the selective enrichment of the nucleosides, adenosine, guanosine, uridine, and inosine, which then were quantified by capillary electrophoresis. The analytes were separated within 10 min using a borate buffer of pH 9.3 (containing sodium dodecyl sulfate) at an operating voltage of 25 kV, a temperature of 20 °C, a sample injection time of 5 s, and with UV detection at 254 nm. The effects of sample pH, sample flow rate, eluent type, and eluent flow rate were optimized. Under the optimized conditions, the enrichment factor was determined to be 10. A linear relationship was obtained over the 0.1 to 100 μg mL −1 concentration range, with regression coefficients of >0.9991. The intra-day and inter-day relative standard deviations of this method were in the range of 3.1–5.0 % and 4.8–7.5 %, respectively. The method was applied to the determination of the nucleosides in (spiked) traditional Chinese medicine injection samples, and recoveries ranged from 70.8 to 106.7 %.
Graphene oxide functionalized with 3-aminophenylboronic acid was prepared for the enrichment of nucleosides combined with capillary electrophoresis. After optimizing various experimental parameters, the method was successfully applied to the determination of nucleosides in traditional Chinese medicine injection samples.
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PLoS One
·
2016
·Vol. 11
·期 2
·e0149032
·
IF 3.057
Zhao Gao,Yu Han,Yunhui Hu,Xiaoyan Wu,Yongbin Wang,Xiaoqun Zhang,Jinjuan Fu,Xue Zou,Jun Zhang,Xiongwen Chen,Pedro A. Jose,Xi Lu,Chunyu Zeng
Both oxidative stress and inflammation are involved in the pathogenesis of contrast-induced nephropathy (CIN). Epigallocatechin-3-gallate (EGCG), a purified catechin from green tea, has antioxidant and anti-inflammatory effects. However, it is unknown whether or not EGCG is effective in treating CIN. Our present study found that intravenous administration of EGCG, either before or just after the establishment of CIN, had a protective effect, determined by normalization of serum creatinine and blood urea nitrogen levels, improvement in renal histopathological scoring and alleviation of apoptosis, accompanied by decreased oxidative stress and inflammation. Because EGCG is a potent inducer of the antioxidant heme oxygenase-1 (HO-1), we studied HO-1 signaling in CIN. HO-1 levels were increased in CIN; treatment with EGCG further increased HO-1 levels, accompanied by an increase in Nrf2, a regulator of antioxidant proteins. Interestingly, blockade of HO-1 with protoporphyrin IX zinc(II) (ZnPP) prevented the protective effect of EGCG on CIN. ZnPP also blocked the ability of EGCG to increase the activity of an antioxidant (superoxide dismutase), and decrease markers of oxidative stress (myeloperoxidase and malondialdehyde) and inflammation (myeloperoxidase and IL-1β), indicating that HO-1 is the upstream molecule that regulates the EGCG-mediated protection. To determine further the role of HO-1 on the EGCG-mediated inhibition of inflammation, we studied the effect of EGCG on the NLRP3 inflammasome, an upstream signaling of IL-1β. EGCG down-regulated NLRP3 expression, which was blocked by ZnPP, indicating that HO-1 links EGCG with NLRP3. Therefore, EGCG, via up-regulation of HO-1, protects against CIN by amelioration of oxidative stress and inflammation.
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RSC Advances
·
2016
·Vol. 6
·期 19
·15354-15361
·
IF 3.289
Xinhuan Lu,Yang chen,Zhenshuang Zhao,Hao Deng,Dan Zhou,Changcheng Wei,Renfeng Nie,Qinghua Xia
The carbon supported 10% Ni catalysts doped with 3‰ Rh have been prepared by an impregnation method. These catalysts have been used to catalyze the one-step hydrogenation of nitrobenzene to cyclohexylamine. The results show that the 3‰ Rh–10% Ni/CSC (biocarbon) catalyst exhibits an excellent performance to achieve 100 mol% conversion of nitrobenzene and 91.6% selectivity of cyclohexylamine under reaction conditions of 3.5 MPa and 140 °C. The recycling tests reveal recyclable stability of 3‰ Rh–10% Ni/CSC. This catalyst is active for the hydrogenation of a series of electron-deficient nitrobenzenes. Some factors such as the type of carriers, the content of Ni and Rh, the type of metals and additives play important roles in controlling the selective hydrogenation.
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TETRAHEDRON
·
2016
·
IF 2.645
Xiong-Wei Liu,Zhen Yao,Jun Yang,Zhi-Yong Chen,Xiong-Li Liu,Zhi Zhao,Yi Lu,Ying Zhou,Yu Cao
A facile and efficient methodology was developed for the synthesis of isoxazole-fused spiropyrrolidine oxindoles 3–5 via a 1,3-dipolar cycloaddition reaction of 3-methyl-4-nitro-5-alkenyl-isoxazoles with azomethine ylides (thermally generated in situ from isatin derivatives and proline or thioproline or sarcosine). Products bearing adjacent quaternary-tertiary centers were smoothly obtained in high yields (up to 90% yield) with good diastereoselectivity (up to 20:1). Furthermore, their biological activity has been preliminarily demonstrated by in vitro evaluation against human prostate cancer cells PC-3, human lung cancer cells A549 and human leukemia cells K562 by the MTT-based assays using the commercially available standard drug Cisplatin as a positive control. These results suggested that most of isoxazole-fused spiropyrrolidine oxindoles 3–5 showed considerable cytotoxicities to these three cell lines K562, A549 and PC-3, and that isoxazole-fused spiropyrrolidine oxindoles may be potential leads for further biological screening.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2017
·Vol. 21
·期 6
·1631-1637
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IF 2.316
Ma Xinying,Wang Xueliang,Chen Meifeng,Li Fuchuan
A novel electrochemical immunoassay for glypicans-3 (GPC3) was established based on its new high affinity antibody (Ig). In this study, we used glass carbon film (GCF) as carrier for immobilizing Ig and avoiding the high electron transfer resistance (Ret) in electrochemical immunoassay sensor (Ig-Biotin-GR/GCE) because many materials such as bovine serum albumin (BSA), avidin, biotin, Ig, GPC3, and ALP were covered on. The Ig was combined with GCP3 labeled alkaline phosphatase (ALP-GPC3) which catalyzes p-nitro phenyl phosphate (PNPP) into p-nitro phenol (PNP). In order to obtain highly sensitive electrochemical signals of the PNP and further determine ALP-GPC3, the GR/GCE modified polylysine (PLYS/GR/GCE) was fabricated and used for detecting the PNP. According to the principle of competitive inhibition, less ALP-GPC3 would be combined with the Ig in the presence of GPC3. By investigating the signals of PNP in the absence and presence of GPC3, GPC3 could be qualitatively and quantitatively analyzed. Under the optimal conditions, the peak current of PNP on the PLYS/GR/GCE was linear with the concentration of GPC3 in the range of 0.75~75 ng mL −1 and a detection limit of 0.2 ng mL −1 . The recognition of GPC3 and detection of PNP were separated, which provides a new way for studying the diagnosis of liver cancer.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
X. Jia,Y.H. Zhao,T. Liu,Y.H. He
Short-term exposure to elevated CO 2 increases cadmium (Cd) uptake in some plant species (wheat, poplars, and willows), which triggers an increase in antioxidative system activity to deal with additional reactive oxygen species that are generated. Here, we examined leaf defenses in Robinia pseudoacacia L. seedlings exposed to elevated CO 2 + Cd for 3 years. Three years of elevated CO 2 decreased Cd uptake into leaves and the Cd content in soils and increased the pH of rhizosphere soil relative to ambient CO 2 . In plants exposed to Cd stress , leaf chlorophyll content was greater under elevated CO 2 than under ambient CO 2 . Superoxide dismutase, peroxidase, and catalase activity increased, glutathione content increased, and malondialdehyde and phytochelatins contents decreased under elevated CO 2 + Cd relative to Cd alone. Proline, soluble sugars, flavonoids, saponins, and phenolic acids contents were greater under elevated CO 2 + Cd than under Cd alone, and condensed tannin content was lower. Overall, long-term elevation of CO 2 enhanced the leaf defense system of R. pseudoacacia exposed to Cd by stimulating antioxidant enzyme activity , osmotic adjustment, and the production of glutathione, flavonoids and phenolic acids. Future research should focus on understanding the mechanisms involved in the decrease in Cd uptake into leaves and Cd content in soils and the increase in rhizosphere soil pH under long-term exposure to elevated CO 2 .
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Nanomaterials
·
2017
·Vol. 7
·期 2
·25
·
IF 3.553
Xiang-Nan Xu,Xiao-Na Guan,Hui-Hua Zhou,Yue-Feng Zhu
3-Hydroxy-2-naphthoic acid hydrazide (HNH), a new reductant and modifier, was applied to reduce and modify graphene oxide (GO) in a one-step process. The obtained HNH reduced graphene oxide (HNH-rGO) was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared spectra (FTIR). The results demonstrated that GO was successfully reduced to graphene and the surface of HNH-rGO was grafted with HNH. The interlayer space was increased from 0.751 nm to 1.921 nm, and its agglomeration was much more attenuated compared with GO. HNH-rGO/polypropylene and graphene/polypropylene composites were synthesized through melt-blending method. The viscosity was enhanced with increased addition of graphene and surface modified graphene demonstrated stronger rheological behavior improving effect than the untreated graphene.Keywords:graphene;reduction;surface modification;nanocomposites
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BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Fengping Liu,Jiaqian Tang,Jun Xu,Yun Shu,Qin Xu,Hongmei Wang,Xiaoya Hu
An amperometric sensor was firstly established for the detection of indole-3-acetic acid (IAA) at low potential based on the hemin/reduced graphene oxide (hemin/rGO) composite. The hemin/rGO nanocomposite was prepared by a simple and facile hydrothermal method without using any reducing agent. It exhibited peroxidase-like activity for the catalytic oxidation of IAA in the presence of oxygen. The consumption of oxygen has a linear relationship with the concentration of IAA in the range from 0.1 to 43 μM and from 43 to 183 μM. The detection limit was down to 0.074 μM. This sensor was unaffected by many interfering substances and stable over time. Such work broadened the application of hemin/rGO and provided a new method for IAA detection.
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ANALYTICAL SCIENCES
·
2024
·Vol. 40
·期 7
·1289-1299
·
IF 1.8
Gong Can,Lu Xiang-Ting,Zhang Shi-Ding,Xiao Kun,Xu Xu
Liquid chromatography‒mass spectrometry employing porous graphite carbon columns and an n-octane-isopropanol mobile phase was utilized for the separation of triacylglycerols (TAGs) in various edible oils, aiming to identify lard adulteration in soybean, corn, and sunflower seed oils. Experiments were conducted using a Hypercarb column (2.1 mm × 100 mm, 5 µm) and an n-octane-isopropanol (70:30, V/V) mobile phase at a flow rate of 0.25 mL· min −1 and a column temperature of 60 °C. Detection was achieved through atmospheric pressure chemical ionization-mass spectrometry. Analysis of diverse edible oil samples revealed that oils of the same type shared similar TAG compositions, while different types exhibited distinct TAG profiles. Distinct variations in triglyceride composition were observed across different edible oils. Based on liquid chromatography‒mass spectrometry analysis, the characteristic component 1-stearic acid-2-palmitic acid-3-oleic acid glyceride (SPO), which may also include PSO, was identified in lard through principal component analysis and orthogonal partial least squares discriminant analysis. This component served as a marker for detecting as low as 0.1% lard adulteration in soybean, corn, and sunflower seed oils. The technique offers a precise and effective approach for the identification of lard adulteration in these edible oils. Graphical abstract
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PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Xiaoxian Hao,Xin Zhang,Wenjing Wang,Wenjing Liu,Guangming Lu,Wenru Zheng,Dirong Gong,Haichao Zhao
The controlled release of antifouling agents from organic coatings is an effective measure against marine biofouling. In this study, Mg Al layered double hydroxides (LDH), a two-dimensional nanoparticle , were intercalated with the 1,2-benzisothiazolin-3-one-based anions (BIT-COO − ) via an ion-exchange process for achieving controlled release of BIT-based antibacterial agent. Multifunctional X-ray photoelectron spectroscopy, thermogravimetric analyzer, and transmission electron microscopy confirmed the successful loading of BIT intercalated into LDH interlayers. The antibacterial performance of LDH@BIT-COOH was tested by the zone of inhibition method, the plate colony counting method, the turbidity method, and the biofilm method, and results proved that 0.4 mg/mL LDH@BIT-COOH exhibited complete inactivation of E. coli (6 h) and S. aureus (12 h ). The release study of the LDH@BIT-COOH proved that the release time prolonged to 4500 min after loading. The 5 wt% LDH@BIT-COOH coating exhibited outstanding antibacterial and antifouling properties by using bio-laser confocal microscope , and without obvious toxicity as observed by L929 cell test using enzyme marker, showing potential applications in marine antifouling.
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