POLYMER BULLETIN
·
2018
·Vol. 76
·期 8
·3971-3987
·
IF 1.589
Chen Xiuqiong,Yan Huiqiong,Sun Wei,Shi Zaifeng,Zhang Wei,Lei Mengyuan,Zhang Pan,Lin Qiang
Since the direct electron transfer of myoglobin (Mb) is hardly realized on the bare electrode, the electrodeposition of the mixture of novel MnO 2 –C composite microsphere, sodium alginate (SA) and Mb on the surface of the carbon ionic liquid electrode (CILE) was conducted to fabricate the modified electrode, denoted as Nafion/Mb–SA–MnO 2 –C/CILE. The biological activity of Mb in the Mb–SA–MnO 2 –C composite was confirmed by FTIR and UV–Vis absorption spectra. The fabricated Nafion/Mb–SA–MnO 2 –C/CILE exhibited a fast electron transfer process with a pair of well-defined redox peaks attributed to the excellent electrochemical property of MnO 2 –C composite microsphere and good biocompatibility of SA that could provide Mb suitable microenvironment to keep its biological activity and facilitate the electron transfer. Additionally, the modified electrode also exhibited a wider linear range and a low detection limit toward the electrocatalytic reduction in trichloroacetic acid with good stability, reproducibility and accurate detection for the real samples.
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高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2018
·
IF 3.441
Bing-huang Wang,Qian Zhang,Jun-ming Hong,Ling Li
Novel iron–carbon–bentonite–alginate beads (Fe°/C-BABs) were successfully prepared with the ion-gelation method and demonstrated high activities in persulfate activation for benzalkonium chloride (BAC) oxidation. The beads were measured in terms of size, mass, and Fe content and then characterized via scanning electron microscopy, energy dispersive spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The performance of Fe°/C-BABs as filler was evaluated in a continuous fixed-bed with paralleled PS and BAC feeding. The effects of initial PS (100 mM) concentration, pH (3–11), fixed bead weight (10–30 g), and flow rate (225-540 mL h −1 ) were investigated. Results indicated that the Fe°/C-BABs effectively activated PS to treat BAC in the solution. The optimal conditions for the degradation of BAC were pH 7.0, [BAC] = 50 mg L −1 , [PS] = 100 mM, bead weight = 30 g, PS flow rate = 25 mL h −1 , and BAC flow rate = 225 mL h −1 ; the removal rate of BAC reached 93.3%.The economic cost analysis was carried out under the optimal experimental conditions. To deeply understand the degradation mechanism of pollutants, the intermediates of BAC degradation were analyzed via gas chromatography/mass spectrometry analysis, and a degradation path pathway was proposed.
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JOURNAL OF PLANT GROWTH REGULATION
·
2019
·Vol. 39
·期 1
·358-369
·
IF 2.179
Cui Dandan,Mo Yuncai,Zeng Lingjie,Feng Kai,Feng Xiaoyun,Huang Jialing,He Mengling,Zhang Xiaoyuan,Teng Xifeng
The response of Dendrobium officinale Kimura et Migo ( D. officinale ) to continuous UV-B irradiation at different carbon to nitrogen ratios (C/N ratios) was investigated. Seedlings grown for 60 days were incubated under aseptic conditions with UV-B irradiation (15.6 µW cm −2 ) at different C/N ratios: control group (CK; C/N 30 without UV-B), UV-B + CK (C/N 30 with UV-B irradiation, similarly hereafter), UV-B + C/N 120, UV-B + C/N 60, UV-B + C/N 15, UV-B + C/N 10, UV-B + C/N 7.5. Growth parameters (the defoliation rate and the sprout number), photosynthetic pigments (carotenoids, chlorophyll a and chlorophyll b), total polysaccharides, total alkaloids, and activities of antioxidant enzymes were determined following 4, 8, 12, and 16 days of continuous UV-B exposure. Results indicated that UV-B irradiation increased the defoliation rate and the content of carotenoids, total polysaccharides and total alkaloids, as well as the activities of antioxidant enzymes. Conversely, UV-B irradiation reduced the sprout number and chlorophyll content in D. officinale . Compared with UV-B + CK, lower C/N ratio treatments (UV-B + C/N 15, UV-B + C/N 10 and UV-B + C/N 7.5) enhanced the defoliation rate and sprout number, but decreased antioxidant enzyme activities and total polysaccharide content during the whole period, and reduced total alkaloid content after 4 days of UV-B exposure. Following initial UV-B irradiation, lower C/N ratios increased the contents of carotenoid and chlorophyll b, while after 8 days, a reversal in carotenoid content was observed, and after 12 days, a reversal in chlorophyll b content was observed. Optimizing the C/N ratio (C/N 60) resulted in lower defoliation rate, higher photosynthetic pigments and total polysaccharides, and increased activities of antioxidant enzymes, whereas no significant change in sprout number and total alkaloid content was recorded under long-term UV-B irradiation. Furthermore, the UV-B + C/N 120 treatment negatively affected D. officinale in terms of an increased defoliation rate and reduced sprout number, photosynthetic pigments, and total alkaloids. Therefore, results suggested that an appropriate C/N ratio (C/N 60) could ameliorate the adverse effects of continuous UV-B irradiation on D. officinale .
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高影响因子
CARBON
·
2018
·
IF 7.082
Hao Mei,Mengran Yang,Yanfei Shen,Fei He,Zhixin Zhou,Xinghua Chen,Yiran Yang,Songqin Liu,Yuanjian Zhang
The efficient and low-cost platinum group metal (PGM)-free metal-nitrogen-carbon electrocatalysts (M-N-C) are potential alternatives for the oxygen reduction reaction (ORR) in artificial energy conversion devices. However, the solid-state reactions of M/C/N-containing precursors at high temperature was rather complicated, making the engineering of carbonization processes of M-N-C catalysts challenging and less explored. Herein, we report a way to modulate the pyrolysis processes of M-N-C by pre-organization of the molecular precursors via a simple solvation , in which, the simultaneous hydrogen bonding and coordination interactions played an important roles. It was revealed that the supramolecular precursors from different solvents had the same chemical compositions but quite different crystal structures. Accordingly, the pyrolysis processes were greatly altered, making the as-prepared Co-N-C exhibit distinct morphologies ranging from worm-nanotubes to bamboo-nanotubes and to porous nanosheets . The optimized Co-N-C showed competitive bifunctional electrocatalytic ORR and OER activities, which were further successfully applied to advance the rechargeable Zn–air batteries with excellent cycling stability over 600 h at a current density of 20 mA cm −2 and voltage gap (0.76 V). This work highlights the great potential of the pre-organization for the designing and selecting of precursors to engineer pyrolyzed M-N-C with higher electrocatalytic activities .
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高影响因子
Molecular Catalysis
·
2018
·
IF 0
Shanshan Jie,Congqiang Yang,Yuan Chen,Zhigang Liu
The highly dispersed active sites are desirable to optimize the atom efficiency. In this study, a series of novel cobalt grafted in N-doped carbon (Co-N-C) catalysts for selective oxidation of ethylbenzene are synthesized by heating a solution of cobalt porphyrin and peptides in ionic liquids, which are also characterized by techniques such as FT-IR, XRD, SEM-EDX, HR-TEM, and XPS. The results show that the as-prepared catalysts have an attractive catalytic performance, namely, 40% of ethylbenzene conversion and 75% of selectivity to acetophenone. Especially, the activity and selectivity of the as-prepared catalysts remain almost similar even after the 10th run. Moreover, the modified-complexometry method is verified to improve the dispersion of metal active sites. The remarkable catalytic performance of the as-prepared catalysts is attributed to the highly dispersed active sites and strong interactions between Co and N species in Co-N x moieties.
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Journal of Materials Chemistry A
·
2014
·Vol. 3
·期 3
·996-1004
·
IF 0
Xue Zhou,Ye Xie,Yuanfu Deng,Xusong Qin,Guohua Chen
The rate performance of LiMnPO4-based materials is further improved via synergistic strategies including a surfactant-assisted solid state method, Fe-substitution and carbon-coating. The surfactant-assisted solid state strategy effectively decreases the primary particle size of the cathode material, which can greatly shorten the diffusion distance of lithium ions. The Fe-substitution improves the effectiveness of Li+ insertion/extraction reactions in the solid phase. The uniform carbon coating layer and the conductive networks provided by the carbon between the nanoparticles ensure the continuous conductivity by the nanoparticles. As a consequence of the synergistic effects, the as prepared LiFe0.5Mn0.5PO4 sample with 6.10 wt% carbon exhibits high specific capacities and superior rate performance with discharge capacities of 155.0, 140.9 and 121 mA h g−1 at 0.1, 1 and 5 C (1 C = 170 mA g−1), respectively. Meanwhile, it shows stable cycling stability at both room temperature (25 °C, 94.8% and 90.8% capacity retention after 500 cycles at 1 and 5 C rates, respectively) and elevated temperature (55 °C, 89.2% capacity retention after 300 cycles at 5 C rate). This material may have great potential application in advanced Li-ion batteries.
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JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2014
·
IF 1.357
Zhang Jianping,Guo Jianfeng,Zhang Yao,Yang Jiao
The graft polymer Dex-g-PSSS was obtained through poly(sodium 4-styrene sulfonate) (PSSS) grafted on dextran(Dex) by using the cerium salt–hydroxyl group redox initiation system. The cross-linked microspheres C(Dex-g-PSSS) were synthesized by suspension polymerization with epichlorohydrin as the cross-linking agent. The chemical structure and physicochemical characteristics of C(Dex-g-PSSS) microspheres were represented by infrared spectroscopy (FTIR), optical microscope, and zeta potential analysis. The aim of the study is to constitute a colon-specific drug delivery system via molecular design, using C(Dex-g-PSSS) microspheres as the drug-carrying material and taking 5-fluorouracil (5-FU) as the model drug. The drug-carrying ability and mechanism of the cross-linked microspheres C(Dex-g-PSSS) for 5-FU were investigated. Finally, in vitro release tests for the drug-carrying microspheres were conducted. The experimental results show that in the medium with pH 2, the cross-linked microspheres C(Dex-g-PSSS) exhibit a strong adsorption ability for 5-FU because of strong electrostatic interactions and have an adsorption capacity of 154 ± 7.5 mg/g, displaying high drug-carrying efficiency. The in vitro release behavior of the drug-carrying microspheres is highly dependent on pH and dextranase. In the medium with pH 2, the drug-carrying microspheres do not release the drug and in the medium with pH 1, they release a little, whereas in the medium with pH 7.4, a sudden delivery phenomenon of the drug will occur, and in the presence of dextranase, a more sudden delivery phenomenon of the drug will occur, displaying an excellent colon-specific drug delivery behavior.
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PubMed
高影响因子
ANALYST
·
2014
·Vol. 139
·期 10
·2499-2506
·
IF 3.906
Qingqing Wen,Xi Zhang,Jiye Cai,Pei-Hui Yang
Cytochrome c (cyt c) and caspase-9 were critical biomarkers in mitochondria-mediated apoptosis. A novel electrochemical immunosensor was developed for in situ analysis of cyt c and caspase-9 in the cytosol. Gold nanoparticle–polydopamine (AuNP/PDA) composites were used to fabricate the interface of the sensor. The anti-cyt c or anti-caspase-9 functionalized-immunosensor provided a biomimetic interface for immunosensing of cyt c or caspase-9 in Hela cells during apoptosis. The changes in the expression level of cyt c and caspase-9 in the cytosol upon curcumin-induced apoptosis were detected by using the proposed method, and also the influence of different concentrations and incubation times of curcumin-induced Hela cells was investigated. This method achieved a linear range (0.1–100 μM) for standard cyt c and caspase-9, with a detection limit of 0.03 ± 0.01 μM for standard cyt c and 0.08 ± 0.02 μM for standard caspase-9. Moreover, this method was used to detect cells which could detect as low as 100 cells which expressed cyt c and caspase-9, and also the results are in good agreement with standard flow cytometry analysis. The developed electrochemical immunosensor offered a simple and rapid approach for sensitive evaluation of apoptosis markers with considerable specificity and reproducibility, and also the developed strategy could be of great importance in clinical diagnosis and therapeutic research.
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PubMed
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 35
·10429-10435
·
IF 0
Peng Yan,Lei Lu,Xiao-min Liu,Yin Cao,Zhi-peng Zhang,Hui Yang,Xiao-dong Shen
A novel, economic and scalable method is proposed in this context using an impinging jet reactor to continuously precipitate FePO4 (FP) nanoparticles with high purity. The LiFePO4/C (LFP/C) nano-composites synthesized from the FP, lithium and carbon sources show fast charge capability and excellent power performance. The generated FP and LFP/C are characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and inductively coupled plasma (ICP) spectrometry. The LFP/C nano-composites are cycled at various C-rates to explore the electrochemical performance. When the pH of the working solution is 1.3, the molar ratio of Fe to P equals 1 in the obtained amorphous FP. In addition, the precipitation mechanism is discussed. Compared to the amorphous FP, the hexagonal FP obtained after calcining the former one is preferred to synthesize high power LFP/C. It is proved that 2 mol% excess LiOH is needed to compensate for the possible loss of Li during calcination. With 4.4 wt% of in situ carbon coating, the LFP/C nano-composites exhibit 145 mA h g−1 at 10 C (1.7 A g−1, 6 min) charge (without floating charge) and discharge, without obvious capacity loss up to 100 cycles, which is among the best high power performances reported so far. This strategy offers an inexpensive and easy control method to mass-produce high quality LFP/C nano-composites which might be suitable for powering hybrid electric vehicles and plug-in hybrid electric vehicles.
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CHINESE JOURNAL OF CATALYSIS
·
2013
·
IF 1.304
Qi SONG,Jiaying CAI,Junjie ZHANG,Weiqiang YU,Feng WANG,Jie XU
Phenethyl phenyl ether (PPE) was selected as a typical lignin model compound and hydrogenated and cleaved over two readily accessible nickel-based catalysts, which could be easily separated from the product mixture. The results revealed that the reduction of the nickel catalyst with gaseous hydrogen produced a species capable of achieving higher activity towards C-O-C bond cleavage compared to the Ru/C and Pd/C catalysts. The selectivity of the C-O-C bond cleavage over the Ni/C catalyst was 85%, and higher than the corresponding values in the Ru/C (40%) and Pd/C (69%) systems. Using the carbothermal reduction method for the production of the Ni/C-C catalyst, the conversion and selectivity levels reached 99%, with 40% of the benzene rings in PPE being reserved. In comparison, no benzene ring containing products wer observed over the noble metal catalysts. This difference was attributed to the interaction between the carbon support and the nickel nanoparticles. 摘要 研究了Ni基催化剂上木质素模型化合物苯基苯乙醚中C–O–C键加氢裂解性能. 结果表明, 14;Ni/C催化剂显示出优异的加氢裂解能力, 14;苯基苯乙醚的转化率达到99%以上. Ni/C催化剂的还原方法对裂解选择性有重要影响; 氢气还原制备的Ni/C-H催化剂上, 14;C–O–C键裂解选择性为85%. Ru/C和Pd/C催化剂上裂解选择性分别为40%和69%. 采用碳热还原方法制备的Ni/C-C催化剂, 14;可以实现高选择性加氢和裂解, 14;C–O–C键裂解选择性达到99%以上, 14;其中芳烃化合物收率为44%. 这可能与镍组分和载体碳之间的相互作用有关.
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高影响因子
MOLECULAR HUMAN REPRODUCTION
·
2014
·Vol. 20
·期 8
·799-809
·
IF 3.483
Wang Yongjie,Tang Chao,Wu Minglan,Pan Yibin,Ruan Hongfeng,Chen Linling,Yao Hongyi,Zhu Haibin,Wu Ximei
We have previously demonstrated that the reduced form of vitamin C (l-ascorbic acid, AA) is able to induce the production of both steroid and peptide hormones in human choriocarcinoma cells. Here, we attempted to investigate the role and underlying mechanism of the oxidized form of vitamin C, dehydroascorbic acid (DHA), in steroidogenesis in primary human cytotrophoblasts and human choriocarcinoma cells. Messenger RNA and protein levels of steroidogenic enzymes including P450 cholesterol side-chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD1), 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) and aromatase were examined by quantitative RT–PCR and western blots, respectively. Progesterone (P4) and estradiol (E2) levels were determined by enzyme immunoassays. Knockdown of c-Jun was achieved by lentivirus-mediated shRNA, and signaling pathways implicated in DHA-induced steroidogenesis were examined by western blots and dual-luciferase assays. DHA dose-dependently induced the expression of steroidogenic enzymes including 3β-HSD1, 17β-HSD1 and aromatase at both mRNA and protein levels, and subsequently increased the production of E2 but not P4. These effects were synergized by diethylmaleate, a glutathione-depleting compound, and α-tocopherol, a reducing agent, but robustly attenuated by inhibition of DHA transportation by phloretin or 2-deoxy-d-glucose. DHA time-dependently inhibited JNK and c-Jun phosphorylation, and dose-dependently reduced AP1 reporter activity. JNK signaling pathway-specific inhibitor SP600125 and c-Jun shRNA both significantly increased the expression of steroidogenic enzymes and E2 production regardless of the presence or absence of DHA. These findings suggest that DHA is able to induce steroidogenesis through inhibition of JNK/c-Jun/AP1 signaling, and may therefore play indispensable roles in pregnancy maintenance.
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PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Xu Yan,Zipeng Xing,Yan Cao,Mengqiao Hu,Zhenzi Li,Xiaoyan Wu,Qi Zhu,Shilin Yang,Wei Zhou
In-situ C-N-S-tridoped single crystal black TiO 2 nanosheets with exposed {001} facets are successfully fabricated via a facile hydrothermal method combined with an in-situ solid-state chemical reduction approach, followed by calcination at 450 °C. The crystal structure, crystallinity, morphology and composition of the as-prepared samples are investigated through X-ray diffraction, Raman, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectroscopy, respectively. The results suggest that the obtained C-N-S-tridoped single crystal black TiO 2 nanosheets exhibit uniform nanosheet-like structure with exposed {001} facets and average length of ∼300–400 nm, thickness of ∼20 nm. The visible-light photocatalytic degradation rate of methyl orange is up to 92.13%, and photocatalytic hydrogen evolution is 149.7 μmol h −1 g −1 . The excellent photocatalytic activity can be ascribed to the synergetic effect of surface heterojunction between {001} and {101} facets, the C-N-S-tridoping, and the formed Ti 3+ species in photocatalyst, which can not only favor the visible-light absorption but also facilitate the separation and transfer of photogenerated charges.
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