MICROPOROUS AND MESOPOROUS MATERIALS
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2019
·
IF 4.182
Ruyue Niu,Pengcheng Liu,Wei Li,Shuang Wang,Jinping Li
0.123%Pd encapsulated in nanosized silicalite-1 (MFI) zeolite catalysts has been prepared by direct hydrothermal conditions, and its catalytic performance at the low concentration methane combustion was studied. The temperatures for methane ignition ( T 10% ), the half-conversion temperature ( T 50% ) and the total conversion temperature ( T 90% ) over Pd/S-1-in (in-situ method) catalyst are 261, 329 and 382 °C, respectively, which are lower than the corresponding temperatures of Pd/S-1-im (incipient impregnation method) catalyst. Moreover, the properties are further enhanced by introducing CeO 2 into the Pd/S-1-in catalyst. The conversion rate decreased slightly from 91 to 85% when the reaction is carried out at 450 °C for 100 h at the gas hourly space velocities (GHSV) of 112500 mL g −1 h −1 . The XPS analysis showed that Pd clusters were encapsulated within the porous rather than on the surface of the crystal by in-situ method. The HRTEM studies demonstrated that the Pd particle encapsulated within Silicalite-1 zeolites are well dispersed and evenly distributed throughout the Silicalite-1 zeolites. The average size of in situ Pd particle encapsulated in Silicalite-1 zeolite is 1.7 nm, which is much smaller than the impregnated Pd/S-1-im catalyst (2.8 nm).
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CATALYSIS LETTERS
·
2019
·Vol. 149
·期 4
·974-984
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IF 2.372
Zhang Xiaotong,He Ning,Liu Chunyan,Guo Hongchen
Highly dispersed Pt–Cu alloy nanoparticles encapsulated in silicalite-1 were prepared by one-pot method. Taking propane dehydrogenation as a probe reaction, it was found that anti-coke ability was improved by encapsulation. Through H 2 -TPR, CO adsorption DRIFT spectra and X-ray Photoelectron Spectroscopy experiment, enhanced anti-coke ability was ascribed to the electronic environment change of encapsulated metal. And it was further confirmed by in situ coking experiment. Owning to limited acidity, metal encapsulated by silicalite-1 molecular sieve exhibited better anti-coke ability and higher propylene selectivity than that by stronger acidic ZSM-5 molecular sieve. Moreover it was found that the combination of Cu and Pt made better catalytic performance and accelerated dehydrogenation more effectively compared with monometallic catalysts. Therefore, Pt–Cu alloy nanoparticles encapsulated in silicalite-1 molecular sieve core–shell material was a potential coke-resistant catalyst for alkane dehydrogenation reaction. Graphical Abstract
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FIBERS AND POLYMERS
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2018
·Vol. 19
·期 10
·2134-2138
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IF 1.353
Wang Zongqian,Li Changlong,Zhang Hulin,Liu Zhi
Chromophore incorporated into the protein chains through residue modification on silk fibroin will be an important way to get new dyeing technology with improved color fastness. Herein, 1-aminoanthraquinone diazonium salt was prepared and used for the modified dyeing on tyrosine of silk fibroin. The silk after modified dyeing was measured by UV-Vis, FTIR, MS, 1 H-NMR, Data color, and other testing techniques. Interestingly, the resulting silk showed excellent rub and wash fastness. The enhanced color fastness is contributed by an electrophilic substitution reaction between 1- aminoanthraquinone diazonium salt and the ortho position of phenolic hydroxyl in tyrosine molecular. Moreover, the mechanical property of silk was protected effectively by the mild coupling modified dyeing, better than the traditional acid dyeing under high temperature for a long time. This facile strategy provides an alternative approach to silk dyeing and benefits the silk applications.
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JOURNAL OF CELLULAR PHYSIOLOGY
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2018
·Vol. 234
·期 5
·7161-7173
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IF 3.923
Xuzhao Wang,Yafei Chen,Junwei Li,Shuai Guo,Xiaoe Lin,Hailin Zhang,Yong Zhan,Hailong An
Mortality-to-incidence ratios in patients with cancer are extremely high, positioning cancer as a major cause of death worldwide. Ether-à-go-go-1 (Eag1) is an ion channel that plays important roles in tumour proliferation, malignant transformation, invasion, metastasis, recurrence, and prognosis. Therefore, identifying potent and specific Eag1 channel inhibitors is crucial. In this study, we identified the first natural inhibitor of Eag1, the traditional Chinese medicine agent tetrandrine, and explored the underlying mechanism. Tetrandrine directly interacted with Eag1 and inhibited the currents in a concentration-dependent manner (IC 50 of 69.97 ± 5.2 μM), and the amino acids Ile 550 , Thr 552 , and Gln 557 in the Eag1 C-linker domain were critical for tetrandrine’s inhibitory effect. Moreover, tetrandrine reduced the proliferation of HeLa cells and Chinese hamster ovary (CHO) cells stably expressing Eag1 in a concentration-dependent manner. Finally, tetrandrine (30 mg/kg/day) inhibited tumor growth in mice, demonstrating a 64.21% inhibitory rate of HeLa cell-transplanted tumors. These results suggest that tetrandrine is a potent and selective Eag1 channel inhibitor, and could act as a leading compound in the development of therapies for Eag1 ion channel dysfunction-induced diseases.
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高影响因子
FREE RADICAL BIOLOGY AND MEDICINE
·
2019
·
IF 5.657
Xueming Cao,Na Zhu,Li Li,Yuwei Zhang,Yan Chen,Jing Zhang,Jiang Li,Chuanyu Gao
Aims Y-box protein 1 (YB1) is a key regulator of inflammatory mediators . However, the roles of YB1 in oxidized low-density lipoprotein (ox-LDL)-induced macrophage inflammation and lipid uptake remain less understood. Thus, we explored the roles of YB1 in ox-LDL-induced macrophage inflammation and lipid uptake and its underlying molecular mechanisms. Methods An ox-LDL-induced atherosclerosis (AS) model was used in this study. Western blotting , RT-PCR, immunofluorescence, ELISA, dil-ox-LDL staining, a dual-luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) and in vivo experiments were used to detect each target. Results ox-LDL downregulates YB1 expression in THP-1-derived macrophages and human monocyte-derived macrophages (hMDMs) via the NF-κB pathway. Downregulation of YB1 is facilitated by lipid uptake in macrophages, and CD36 is involved in this process. Furthermore, YB1 suppresses CD36 protein levels by directly binding to the coding sequence of the CD36 gene to promote CD36 mRNA decay but does not affect its mRNA transcription. Additionally, YB1 knockdown enhances the inflammatory response and lipid deposition via the NF-κB pathway in vivo. Conclusion ox-LDL decreases YB1 expression in macrophages, resulting in enhanced inflammatory responses by affecting NF-κB and facilitating lipid uptake by promoting scavenger receptor CD36 mRNA decay.
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高影响因子
RSC Advances
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2018
·Vol. 8
·期 15
·8372-8384
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IF 2.936
Guangzheng Zuo,Yuebing Xu,Jiao Zheng,Feng Jiang,Xiaohao Liu
Supported W catalysts were extensively investigated for the conversion of 1-butene and ethylene into propene by metathesis reaction. The performance of catalysts was compared by using unsupported WO3, pure SBA-15, supported W/SBA-15 with different W loadings, varied calcination temperatures, and by changing the pretreatment gas atmosphere. The above catalytic results could be employed to deduce the reaction mechanism combined with characterization techniques such as BET, XRD, UV-vis DRS, Raman, pyridine-IR, XPS, and H2-TPR. In this study, over the investigated W/SBA-15 catalysts, the results showed that the silanol group (Si–OH) in SBA-15 could act as a weak Brønsted acid site for 1-butene isomerization. However, the metathesis reaction was catalyzed by W-carbene species. The initially formed W-carbenes (WCH–CH3) as active sites were derived from the partially reduced isolated tetrahedral WOx species which contained WO or W–OH bonds in W5+ species as corresponding Lewis or Brønsted acid sites. Furthermore, the W/SBA-15 being pretreated by H2O led to a complete loss of the metathesis activity. This was mainly due to the sintering of isolated WOx species to form an inactive crystalline WO3 phase as demonstrated by XRD patterns. On the other hand, the reduction of WOx species remarkably suppressed by H2O pretreatment was also responsible for the metathesis deactivation. This study provides molecular level mechanisms for the several steps involved in the propene production, including 1-butene isomerization, W-carbene formation, and metathesis reaction.
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COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2018
·
IF 4.514
Jiajia Liu,Wei Wang,Richard K.K. Yuen,Zhou Gui,Yuan Hu
SnO 2 nanowires decorated MnO 2 nanosheets hybrids, were prepared and incorporated into epoxy resins to improve the flame retardancy and inhibite the smoke in combustion. SnO 2 -MnO 2 hybrids shows significant improve in flame retardancy, fire toxicity and thermal properties of epoxy nanocomposites, compared to neat epoxy and nanocomposites with a single SnO 2 or MnO 2 . The char residues and glass transition temperature of the epoxy/2 wt% SnO 2 -MnO 2 nanocomposite were remarkably increased. The peak heat release rate of EP/2 wt% SnO 2 -MnO 2 was significantly decreased by 62.9% than that of pure epoxy. TG-FTIR results that the concentration of organic volatiles of epoxy was significantly reduced and the toxic CO was suppressed after incorporating SnO 2 -MnO 2 . The physical barrier for SnO 2 -MnO 2 hybrids and the synergism between the catalysis effect of SnO 2 and MnO 2 can improve the flame retardancy of epoxy resin.
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ACS Catalysis
·
2018
·
IF 11.384
Tianliang Lu,Junpeng Zou,Yuzhong Zhan,Xiaomei Yang,Yiqiang Wen,Xiangyu Wang,Lipeng Zhou,Jie Xu
Highly efficient oxidation of ethyl lactate (ELA) to ethyl pyruvate (EP) was realized over TS-1 in the presence of aqueous H2O2 (30 wt %) at low temperature without other solvent. A 100% ELA conversion and 97.8% EP yield were obtained at 50 °C after 9 h. The conversion rate of ELA is sensitive to the reaction temperature. High reaction temperature (70 °C) leads to an increase in conversion rate of ELA but causes the fast hydrolysis and decarboxylation of EP to form byproducts of acetic acid and CO2. On the basis of the characterization (pyridine-FTIR and UV–vis) and reaction results, active species of Ti(OOH) were proven. In addition, a nonradical mechanism for conversion of ELA to EP for this catalytic system was proposed. By kinetic analysis, the formation of Ti(OOH) is confirmed as the rate-determining step. The apparent activation energy (103.4 kJ mol–1) was also obtained. Furthermore, TS-1 was highly stable for the oxidation of ethyl lactate. There were almost no change in ELA conversion and EP yield throughout 10 reaction runs.
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RSC Advances
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2018
·Vol. 8
·期 31
·17389-17398
·
IF 2.936
Yunquan Zheng,Qisheng Pan,Liuda Mo,Wenyi Zhang,Yunjian Duan,Chengqun Chen,Haijun Chen,Yanghao Guo,Xianai Shi,Jianmin Yang
Alzheimer's disease (AD) is an extremely complex disease, characterized by several pathological features including oxidative stress and amyloid-β (Aβ) aggregation. Blockage of Aβ-induced injury has emerged as a potential therapeutic approach for AD. Our previous efforts resulted in the discovery of Monascus pigment rubropunctatin derivative FZU-H with potential neuroprotective effects. This novel lead compound significantly diminishes toxicity induced by Aβ(1-42) in Neuro-2A cells. Our further mechanism investigation revealed that FZU-H inhibited Aβ(1-42)-induced caspase-3 protein activation and the loss of mitochondrial membrane potential. In addition, treatment of FZU-H was proven to attenuate Aβ(1-42)-induced cell redox imbalance and Tau hyperphosphorylation which caused by okadaic acid in Neuro-2A cells. These results indicated that FZU-H shows promising neuroprotective effects for AD.
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高影响因子
JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY
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2018
·
IF 1.418
Ying Guo,Jian-Qiang Chen,Meng Su,Jian-Guo Hong
Lignocellulosic biomass is regarded as one of the most abundant and sustainable resources for the development of bio-based plastics. The esterification of wood with phthalic anhydride (PA) yields low content due to lack of an efficient modification medium. In the present study, 1-methylimidazole was used as a catalytic medium for the highly efficient esterification of waste lignocellulosic biomass (poplar wood, mulberry wood, and wheat straw) with PA. After modification, the wood particles were plasticized and molded via injection molding. Analyses of the weight percent gain showed that under the same conditions, poplar wood, which has a soft and loose structure, presented the highest extent of esterification, whereas mulberry wood, which has a tight texture, had the lowest extent of esterification. Mulberry wood-based plastics exhibited the best performance in terms of flexural and tensile strength. Notably, short reaction time was favorable to produce bio-based plastics that were light in color. FT-IR spectroscopy and solid-state 13 C NMR spectroscopy confirmed the chemical structures of the esterified products. Dynamic mechanical analysis was used to identify the storage modulus and the damping factor of the esterified products. Analyses of the morphologies of the materials demonstrated different composite structures for the bio-based plastics, which played an important role in their mechanical performance.
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AMB Express
·
2019
·Vol. 9
·期 1
·1-9
·
IF 2.226
Zhao Shuxue,Hu Chunhui,Guo Lizhong,Li Kuiran,Yu Hao
A 3-hydroxypyridine degrading bacterium, designated strain DW-1, was isolated from petroleum contaminated soil in Liao River China. 16S rRNA-based phylogenetic analysis indicates that strain DW-1 belongs to genus Agrobacterium. The optimal cultivation temperature and pH for strain DW-1 with 3-hydroxypyridine were 30 °C and 8.0, respectively. Under optimal conditions, strain DW-1 could completely degrade up to 1500 mg/L of 3-hydroxypyridine in 66 h. The 3-hydroxypyridine degradation pathway of strain DW-1 was suggested by HPLC and LC–MS analysis. The first reaction of 3-hydroxypyridine degradation in strain DW-1 was α-hydroxylation so that the major metabolite 2,5-dihydroxypyridine was produced, and then 2,5-dihydroxypyridine was transformed by a Fe2+-dependent dioxygenase to form N-formylmaleamic acid. N-Formylmaleamic acid will be transformed to maleic acid and fumaric acid through maleamic acid. This is the first report of the 3-hydroxypyridine degradation pathway and the utilization of 3-hydroxypyridine by a Agrobacterium sp. It may be potentially used for the bioremediation of environments polluted with 3-hydroxypyridine.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Yang Xiang,Xiaohui Duan,Longbao Feng,Shuqi Jiang,Li Deng,Jun Shen,Yijun Yang,Rui Guo
The successful treatment of gliomas relies on two important factors, namely therapeutic genes/drugs and efficient delivery vehicles to cross the blood-brain barrier. In this work, a new gene vector was constructed based on polycaprolactone (PCL), glutathione (reduced; GSH)-sensitive polyethylenimine (PEI-SS) and polyethylene glycol (PEG), and modified with a cell-penetrating peptide (tLyp-1); this yielded tLyp-1-conjugated GSH-sensitive biodegradable micelles (PPPt) that mediated enhanced tumour necrosis factor (TNF)-related apoptosis-inducing ligand (pUNO1-hTRAILa) and curcumin (CUR) co-delivery to gliomas. The sensitisation function of CUR was used to explore whether CUR and genes have a synergistic antitumour effect. The results showed that the drug loading efficiency of PPPt was about 8.6%. The PPPt possessed good cytocompatibility and blood compatibility when the concentration was less than 0.06 mg/mL. PPPt strongly condensed pUNO1-hTRAILa to form a nanocomplex and efficiently transfected C6 cells. The drug-release behaviour of PPPt/CUR/pUNO1-hTRAILa was reduction-sensitive and the cellular uptake results indicate that modification of tLyp-1 promoted the internalisation of micelles. The PPPt/CUR/pUNO1-hTRAILa complexes exhibited much better in vitro and in vivo antitumour effects than micelles loaded with CUR or pUNO1-hTRAILa alone. We also used magnetic resonance imaging for in vivo monitoring of the transcranial drug delivery and therapeutic effect of the tumour on rats bearing in situ glioma.
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