Chinese Physics B
·
2018
·Vol. 27
·期 9
·097301
·
IF 1.321
Ang Li,Jin-Lei Wu,Xue-Song Xu,Yang Liu,Ya-Nan Bao,Bin Dong
The W18O49 nanoflowers with a diameter of 500 nm are prepared by a facile hydrothermal method. The Er–Yb: NaYF4 nanoparticles are adsorbed on the petals (the position of the strongest local electric field on W18O49 nanoflowers). With a 976 nm laser diode (LD) as an excitation source, the selectively green upconversion luminescence (UCL) is observed to be enhanced by two orders of magnitude in Er–Yb: NaYF4/W18O49 nanoflowers heterostructures. It suggests that the near infrared (NIR)-excited localized surface plasmon resonance (LSPR) of W18O49 is primarily responsible for the enhanced UCL, which could be partly reabsorbed by the W18O49, thus leading to the selective enhancement of green UCL for the Er–Yb: NaYF4. The fluorescence intensity ratio is investigated as a function of temperature based on the intense green UCL, which indicates that Er–Yb: NaYF4/W18O49 nanoflower heterostructures have good potential for developing into temperature sensors.
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Chinese Journal of Natural Medicines
·
2018
·
IF 1.991
Yan-Zi LI,Zhi-Na MA,Yin-Shi SUN,Shen REN,Shuang JIANG,Wei-Zhe ZHANG,Zi WANG,Wei LI
The present study was designed to evaluate protective activity of an ethanol extract of the stems of Schisandra chinensis (SCE) and explore its possible molecular mechanisms on acetaminophen (APAP) induced hepatotoxicity in a mouse model. The results of HPLC analysis showed that the main components of SCE included schisandrol A, schisandrol B, deoxyschisandrin, schisandrin B, and schisandrin C and their contents were 5.83, 7.11, 2.13, 4.86, 0.42 mg·g −1 , respectively. SCE extract was given for 7 consecutive days before a single hepatotoxic dose of APAP (250 mg·kg −1 ) was injected to mice. Our results showed that SCE pretreatment ameliorated liver dysfunction and oxidative stress, which was evidenced by significant decreases in aspartate transaminase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA) contents and elevations in reduced glutathione (GSH) and superoxide dismutase (SOD) levels. These findings were associated with the result that the SCE pretreatment significantly decreased expression levels of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT). SCE also significantly decreased the expression levels of Bax, mitogen- activated protein kinase (MAPK), and cleaved caspase-3 by APAP exposure. Furthermore, supplementation with SCE suppressed the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), suggesting alleviation of inflammatory response. In summary, these findings from the present study clearly demonstrated that SCE exerted significant alleviation in APAP-induced oxidative stress, inflammation and apoptosis mainly via regulating MAPK and caspase-3 signaling pathways.
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PubMed
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2018
·
IF 0.824
Qiang LI,Yuan-Yuan LI,Nan ZHU,Zhu-Xian GAO,Tian-Jun LI,Tong ZHOU,Yu-Long MA
Graphene oxide (GO) was covalently coupled to the surface of amino silica gel by amide bond. β -cyclodextrin ( β -CD) was further chemically bonded with GO to prepare a novel chiral stationary phase. The resulting material was characterized by Fourier transform-infrared (FT-IR) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analysis and thermogravimetric analysis (TGA). The separation of seven enantiomers was improved in varying degrees. Meanwhile, the stationary phase showed typical characteristics of hydrophilic interaction chromatography (HILIC), and four small nucleoside molecules were separated with the mobile phase of methanol-acetonitrile-water (45:45:10, V/V ) in the HILIC mode. In addition, the separation mechanism of the stationary phase was further explored by studying the effects of mobile phase composition, temperature and pH value on the analyte retention. The low temperature was conducive to the separation of analytes at 20–60 °C. The addition of protonated solvent methanol significantly decreased the retention time of the four analytes. The change of pH affected the degree of protonation of the analyte, the interaction between analytes and the stationary phase, and retention time of analytes. The results showed that GO and β -CD played a synergistic effect in the chiral resolution of the chromatographic stationary phase. The retention of analytes in HILIC was attributed to their mixed-mode retention mechanisms including hydrophilic interaction, electrostatic interaction, hydrogen bonding, π-π stacking and so on.
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CHINESE JOURNAL OF CATALYSIS
·
2018
·
IF 3.525
Yanyan Guo,Chengna Dai,Zhigang Lei
We studied the hydrogenation of 2-ethylanthraquinone (eAQ) over Pd/SiO 2 /COR (COR = cordierite) monometallic and Pd-M/SiO 2 /COR (M = Ni, Fe, Mn, and Cu) bimetallic monolithic catalysts, which were prepared by the co-impregnation method. Detailed investigations showed that the particle sizes and structures of the Pd-M (M = Ni, Fe, Mn, and Cu) bimetallic monolithic catalysts were greatly affected by the second metal M and the mass ratio of Pd to the second metal M. By virtue of the small particle size and the strong interaction between Pd and Ni of Pd-Ni alloy, Pd-Ni bimetallic monolithic catalysts with the mass ratio of Pd/Ni = 2 achieved the highest H 2 O 2 yield (7.5 g/L) and selectivity (95.3%). Moreover, density functional theory calculations were performed for eAQ adsorption to gain a better mechanistic understanding of the molecule-surface interactions between eAQ and the Pd(1 1 1) or PdM(1 1 1) (M = Ni, Fe, Mn, and Cu) surfaces. It was found that the high activity of the bimetallic Pd-Ni catalyst was a result of strong chemisorption between Pd 3 Ni 1 (1 1 1) and the carbonyl group of eAQ.
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NEW CARBON MATERIALS
·
2018
·
IF 1.171
Ju-meng Wei,Bi-tao Liu,Xin Zhang,Chang-chun Song
N and S co-doped carbon quantum dots (N, S-CQDs) with a high fluorescence quantum yield (12.6%) were synthesized by a one-pot hydrothermal method. Results indicate that the N, S-CQDs have a small particle size and an amorphous structure, exhibiting unique surface states and excitation wavelength-independent fluorescent properties. Co-doping of N and S increases the electron-transfer rate and improves the coordination interaction between the N, S-CQDs and Hg 2+ ions. The N, S-CQDs show a high sensitivity and selectivity in detecting Hg 2+ ions even for a lake water sample. They are promising fluorescence probes for environmental monitoring.
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CHINESE JOURNAL OF CATALYSIS
·
2017
·
IF 2.813
Yi Liu,Xuanmu Zhou,Zhehui Zhang,Bingguang Zhang,Kejian Deng
The photocatalytic activity of cobalt octakis(butylthio) porphyrazine (CoPz(BuS) 8 ) was assessed through photodegradation of the dye rhodamine B (RhB) in water under irradiation with a Xe lamp and aerated conditions. The photocatalytic activity of CoPz(BuS) 8 loaded on Al 2 O 3 or SiO 2 @Fe 3 O 4 nanoparticles or coordinated with an axial azide ligand was also investigated. The results demonstrated that the photocatalytic activity of CoPz(BuS) 8 loaded on Al 2 O 3 was higher than that loaded on SiO 2 @Fe 3 O 4 . The kinetic curves of RhB degradation in aqueous solutions at different pH indicated the pseudo first-order kinetics of the reaction. The highest degradation rate for CoPz(BuS) 8 loaded Al 2 O 3 at pH = 4 after 160 min was 84.6%. However, the advantages of easier separation and recycling as well as the ability to terminate the reaction at any time for the CoPz(BuS) 8 loaded SiO 2 @Fe 3 O 4 cannot be ignored. When electron-rich NaN 3 was coordinated with CoPz(BuS) 8 as an axial ligand and loaded on Al 2 O 3 , the resulting catalyst produced more active oxygen species such as O 2 − and HO • to promote the quicker degradation of RhB than that by the other catalysts. For the N 3 -coordinated CoPz(BuS) 8 loaded on Al 2 O 3 , the reactions at pH = 4 and 7 distinctly deviated from first-order kinetics, and the degradation rate reached 77.6% after 80 min at pH = 4.
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Materials Research Express
·
2016
·Vol. 3
·期 9
·095020
·
IF 0.968
Congyue Wang,Chunfeng Wang,Dong Sun,Aoqi Li,Yujuan Chen,Kelei Zhuo
Heteroatom doped carbon dots (CDs) possess many unique properties and have attracted increasing attention. The precursor is vital for the preparation of highly fluorescent heteroatom doped CDs. Herein, 1, 3-bis(carboxymethyl)imidazolium chloride ([Im(AH)2]Cl, a COOH-functional ionic liquid) and aminoethylethanolamine (AEEA) were firstly used as precursors to prepare nitrogen-doped carbon dots (N-CDs) by a simple one-step pyrolysis approach. The effects of reaction time, temperature, and mass ratio of precursors on the quantum yield (QY) of N-CDs were investigated. The prepared N-CDs are spherical morphology with an average diameter of 2.4 nm, and have blue fluorescence with a QY of 23.2% and excitation-dependent emission behavior. They also possess good water solubility and fluorescent stability. In addition, based on the obtained N-CDs, a sensing method of free chlorine detection in acidic water system was introduced. The proposed method has good sensitivity and selectivity to free chlorine, and exhibits a nice linear response in the concentration range from 0.2 to 22 μM with a detection limit of 0.15 μM. Furthermore, this sensing method was successfully applied to detect free chlorine of tap water with satisfactory recovery (97%–103%), suggesting it has the potential application in water quality monitoring.
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NANOTECHNOLOGY
·
2016
·Vol. 27
·期 9
·095603
·
IF 3.573
Jingjie Cui,Jing Chen,Shaowei Chen,Li Gao,Ping Xu,Hong Li
Cancer is a cell dysfunction disease. The detection of cancer cells is extremely important for early diagnosis and clinical treatments. At present, the pretreatment for the detection of cancer cells is costly, complicated and time-consuming. As different species of the analytes may give rise to specific voltammetric signals at distinctly different potentials, simple potential sensing has the specificity to detect different cellular species. By taking advantage of the different electrochemical characteristics of normal cells, cancer cells and biointeractions between anticancer drugs and cancer cells, we develop a specific, sensitive, direct, cost-effective and rapid method for the detection of cancer cells by electrochemical potential sensing based on Au/TiO2 nanobelt heterostructure electrodes that will be of significance in early cancer diagnosis, in vitro screening of anticancer drugs and molecular biology research.
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PubMed
高影响因子
NEW CARBON MATERIALS
·
2016
·
IF 0.993
Yue Wang,Wen-ting Wu,Ming-bo Wu,Hong-di Sun,Hui Xie,Chao Hu,Xue-yan Wu,Jie-shan Qiu
Yellow-visual fluorescent carbon quantum dots (CQDs) were prepared from petroleum coke by ultrasonic-assisted chemical oxidation and were used as label-free probes for Cu 2+ detection in water. The detection of Cu 2+ by CQD probes is related to a quenching of fluorescence by a photoinduced electron transfer mechanism. The quenched fluorescence of the CQDs by Cu 2+ can be recovered by adding ethylene diamine tetraacetic acid. The yellow-visual fluorescent CQD probes have a linear detection range from 0.25 to 10 μM, a detection limit of 0.0295 μM, a response time of 3 s, and a superior sensitivity and selectivity for Cu 2+ detection compared to other fluorescent probes. The CQDs are easy to prepare, economical, reusable, fast to respond and can be used in on-line detection.
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Chinese Journal of Natural Medicines
·
2016
·
IF 1.382
Zhi-Shen XIE,Ling-Jun ZHONG,Xiao-Meng WAN,Meng-Ning LI,Hua YANG,Ping LI,Xiao-Jun XU
As a culinary and medicinal herb, rosemary is widely used. The present work aimed to investigate the effects of rosemary extracts on metabolic diseases and the underlying mechanisms of action. Liver cells stably expressing SREBP reporter were used to evaluate the inhibitory effects of different fractions of rosemary extracts on SREBP activity. The obese mice induced by Western-type diet were orally administered with rosemary extracts or vehicle for 7 weeks, the plasma and tissue lipids were analyzed. SREBPs and their target genes were measured by quantitative RT-PCR. We demonstrated that the petroleum ether sub-fraction of rosemary extracts (PER) exhibited the best activity in regulating lipid metabolism by inhibiting SREBPs, while water and n -BuOH sub-fraction showed the SREBPs agonist-effect. After PER treatment, there was a significant reduction of total SREBPs in liver cells. PER not only decreased SREBPs nuclear abundance, but also inhibited their activity, resulting in decreased expression of SREBP-1c and SREBP-2 target genes in vitro and in vivo . Inhibiting SREBPs by PER decreased the total triglycerides and cholesterol contents of the liver cells. In the mice fed with Western-type diet, PER treatment decreased TG, TC, ALT, glucose, and insulin in blood, and improved glucose tolerance and insulin sensitivity. Furthermore, PER treatment also decreased lipid contents in liver, brown adipose tissue, and white adipose tissue. Our results from the present study suggested that petroleum ether fraction of rosemary extracts exhibited the best potential of improving lipid metabolism by inhibiting SREBPs activity.
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PubMed
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CHINESE JOURNAL OF CATALYSIS
·
2017
·
IF 2.813
Na Huo,Hong Ma,Xinhong Wang,Tianlong Wang,Gang Wang,Ting Wang,Leilei Hou,Jin Gao,Jie Xu
ABSTRACT From both fundamental and practical perspectives, the production of chemicals from biomass resources using high-efficiency non-precious metal catalysts is important. However, many processes require addition of stoichiometric or excess quantities of base, which leads to high energy consumption, leaching problems, and side reactions. In this study, we investigated the high-efficiency oxidative esterification of furfural to methylfuroate by molecular oxygen with a Co-N-C/MgO catalyst. The catalyst was prepared by direct pyrolysis of a cobalt(II) phenanthroline complex on MgO at 800 °C under N 2 atmosphere. From furfural, 93.0% conversion and 98.5% selectivity toward methylfuroate were achieved under 0.5 MPa O 2 with reaction at 100 °C for 12 h without a basic additive. The conversion and selectivity were much higher than those obtained with cobalt catalysts produced by pyrolysis of a cobalt(II) phenanthroline complex on activated carbon or typical basic supports, including NaX, NaY, and CaO. X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and experimental results revealed that the high efficiency of Co-N-C/MgO for production of methylfuroate was closely related to the cobalt-nitrogen-doped carbon species and its catalytic ability in hydrogen abstraction. In contrast, Co-N-C(HCl) that synthesized by removing MgO with HCl from Co-N-C/MgO, as the catalyst produced mainly an acetal as a condensation product, and chloride ions had a negative effect on the oxidative esterification. Although the catalytic performance of the cobalt-nitrogen-doped carbon species was greatly affected by HCl treatment, it could be recovered to a great extent by addition of MgO. Moreover, changes in the oxygen pressure hardly affected the oxidative esterification of furfural with Co-N-C/MgO. This study not only provides an effective approach to prepare methylfuroate, but also for designing high-performance non-precious metal catalysts for the oxidative esterification of biomass-derived compounds.
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JOURNAL OF RARE EARTHS
·
2017
·
IF 2.429
Feng WANG,Wenbo WANG,Yongfeng ZHU,Aiqin WANG
CTS- g -(AA- co -SS)/ISC hybrid hydrogel adsorbent with crosslinked network structure and superior adsorption performance for rare-earth metal ions was successfully synthesized in aqueous solution by a simple one-step free-radical grafting polymerization reaction among acrylic acid (AA), sodium p -styrenesulfonate (SS) and chitosan (CTS) using illite/smectite clay (ISC) as the inorganic additive. The structure of the as-prepared CTS- g -(AA- co -SS)/ISC hydrogel adsorbent was characterized, and the reaction parameters such as AA/SS molar ratio and ISC content were optimized, and the effects of pH values, initial concentration and contact time on the adsorption performance for Ce(III) and Gd(III) were systematically evaluated. It was found that the maximum adsorption capacities of the hydrogel adsorbent toward Ce(III) and Gd(III) reached 174.05 and 223.79 mg/g, respectively, and the adsorption quickly achieved equilibrium within 15–20 min. The adsorbed Ce(III) and Gd(III) could be easily desorbed for recovery, and the used adsorbent was able to be regenerated for reuse. After five adsorption-desorption cycles, the regenerated adsorbent could still retain the adsorption capacities that were close to the initial value. The adsorption process was well described by pseudo-second-order kinetic mode and the Langmuir isotherm model, and the chemical complexation between ions and –COO – was mainly responsible for the high adsorption capacity. As a whole, the hybrid hydrogel adsorbent was potential to be used for the adsorption and recovery of Ce(III) and Gd(III) from water.
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