FOOD CHEMISTRY
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2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Ling Zhang,Sihua Cheng,Lanting Zeng,Fang Dong,Ziyin Yang
1-Phenylethanol is a chiral flavor compound that has enantiomers, ( R )- and ( S )-1-phenylethanol, with different flavor properties. Given that isolating these enantiomers from plants is low yielding and costly, enzymatic synthesis presents an alternative approach. However, the genes/enzymes that specifically produce ( R )- and ( S )-1-phenylethanol in plants are unknown. To identify these enzymes in tea ( Camellia sinensis ) flowers, 21 short chain dehydrogenase (SDR) genes were isolated from tea flowers, cloned, and functionally characterized. Several recombinant SDRs in Escherichia coli exhibited activity for converting acetophenone to ( S )-1-phenylethanol (CsSPESs, >99.0%), while only one SDR produced ( R )-1-phenylethanol (CsRPES, 98.6%). A pair of homologue enzymes (CsSPES and CsRPES) showed a strong preference for NADPH cofactor, with optimal enzymatic reaction conditions of 45–55 °C and pH 8.0. Identification of the tea flower-derived gene responsible for specific synthesis of ( R )- and ( S )-1-phenylethanolsuggests enzymatic synthesis of enantiopure 1-phenylethanol is possible using a plant-derived gene.
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ACS Catalysis
·
2018
·
IF 11.384
Yue Yan,Zihao Zhang,Seong-Min Bak,Siyu Yao,Xiaobing Hu,Zulipiya Shadike,Chi-Linh Do-Thanh,Feng Zhang,Hao Chen,Xilei Lyu,Kequan Chen,Yimei Zhu,Xiuyang Lu,Pingkai Ouyang,Jie Fu,Sheng Dai
Chemocatalysis of sugars to methyl lactate (MLA) exhibits great advantages over the conventional fermentation approach because of its higher productivity and cost-effective separation process. However, widely used supported metal oxide catalysts suffer from deactivation resulting from sintering during the reaction and removal of coke at high temperatures. Herein, we report ultrasmall cobalt oxide clusters (∼1.7 nm) stabilized within silicalite-1 crystals catalyst (CoO@silicalite-1), exhibiting superior catalytic activity and resistance to sintering for the conversion of fructose into methyl lactate. HAADF-STEM, EDS-mapping, and XRD experiments identify the existence of confined CoO clusters. XANES and Raman spectra demonstrated the covalent interaction between CoO and silicalite-1. Thanks to the ultrasmall CoO particle size (∼1.7 nm), the CoO@silicalite-1 affords nearly 100-fold higher Co-mass-based activity (mg MLA/mg Co) compared with CoO or Co3O4 particles outside the silicalite-1 framework. More importantly, this catalyst exhibits good reuse performance via the removal of coke with facile calcination.
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Frontiers in Neuroscience
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2019
·
IF 3.648
Chen Xiao,Xi Zhiyu,Liang Huaibin,Sun Yuhao,Zhong Zhihong,Wang Baofeng,Bian Liuguan,Sun Qingfang
Secondary injuries mediated by oxidative stress lead to deterioration of neurological functions after intracerebral hemorrhage (ICH). Cortical astrocytes are among the most important cells in the central nervous system (CNS), and play key roles in maintaining redox homeostasis by providing oxidative stress defense. Hemin is a product of hemoglobin degradation, which has strong toxicity and can induce reactive oxygen species (ROS). Melatonin (Mel) and its metabolites are well tolerated without toxicity, prevent tissue damage as well as effectively assist in scavenging free radicals. We evaluated the hemin neurotoxicity to astrocytes and the resistance of Mel-treated astrocytes to hemin neurotoxicity. And we found Mel induced PKCα phosphorylation (p-PKC), nuclear translocation of Nrf2 in astrocytes, and upregulation of HO-1, which contributed to the reduction of ROS accumulation and cell apoptosis. Nrf2 and HO1 protein expression upregulated by Mel were decreased after administration of PKC inhibitor, Ro 31-8220 (Ro 31). Luzindole (Luz), a melatonin receptor inhibitor, suppressed p-PKCα, HO-1, and Nrf2 expression upregulated by Mel and increased cell apoptosis rate. The upregulation of HO-1 induced by Mel was depressed by knocking down Nrf2 expression by siRNA, which also decreased the resistance of astrocytes to toxicity of hemin. Mel activates astrocytes through PKCα/Nrf2/HO-1 signaling pathway to acquire resistance to toxicity of hemin and resist from oxidative stress and apoptosis. The positive effect of Mel on PKCα/Nrf2/HO-1 signaling pathway may become a new target for neuroprotection after intracerebral hemorrhage.
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Scientific Reports
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2019
·Vol. 9
·期 1
·1-13
·
IF 4.011
Huang Yifeng,Ma Yongwen,Wan Jinquan,Wang Yan
In this study, the hydrodynamic characteristic of a lab-scale internal circulation (IC) anaerobic reactor was investigated. We found that the gradual Increasing-Size Continuous Stirred-Tank Reactors (ISC) model is desirable to describe the hydraulic character of the reactor. As a generalized anaerobic digestion model, Anaerobic Digestion Model No.1 (ADM1) was combined simultaneously with the ISC model to simulate the effluent of the IC reactor. Both the stable running and overloading shock tests were carried out to validate the simulation. The mathematical simulation results agreed well with the experimental observation. This proposed model may be valuable to simulate the performance of the IC reactor effectively and to supply a useful tool to for designing and operating other anaerobic reactors.
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GREEN CHEMISTRY
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2019
·Vol. 21
·期 9
·2286-2294
·
IF 9.405
Yuqing Qin,Fei Peng,Yonggang Hu
The oxidation of As(III) to As(V) is a critical process in the treatment of contaminated water. We found that 95% As(III) (10 mg L−1) could be rapidly oxidized to As(V) by a laccase–2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system in 1 h. Based on this finding, we used Bacillus subtilis spores instead of laccase for As(III) oxidation with the same effect because the former had plenty of CotA–laccase on their surface. The catalytic ability of CotA protein and spores was confirmed by expressing the CotA protein and knocking out the cotA gene from wild-type spores. Both laccase– and spore–TEMPO systems displayed similar oxidation rate constants, Michaelis–Menten constants, and maximal velocities owing to the formation of the oxoammonium cation of TEMPO in the presence of dissolved oxygen. Several other laccase mediators such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) (ABTS), acetosyringone (AS), 1-hydroxybenzotriazole (HBT), 2-hydroxybutyl acrylate (HBA), violuric acid (VLA), 4-oxo-TEMPO, 4-amino-TEMPO, 4-methoxy-TEMPO, 4-hydroxy-TEMPO benzoate, and 4-hydroxy-TEMPO coupled with spores for As(III) oxidation were also investigated in detail. The spore–TEMPO system exhibited the highest oxidation efficiency and tolerated the addition of 10 mg L−1 Al3+, Ti4+, Cu2+, K+, Fe3+, Zn2+, Ni2+, Mg2+, Co2+, and Mn2+. Both laccase and spores recovered via ultrafiltration and centrifugation, respectively, could be reused for at least five cycles. The developed spore-based system has several advantages including eco-friendliness, ease of operation and storage, low cost, recyclability, sustainability, and without the need for enzyme purification. These findings may have promising implications for developing a new eco-friendly and cost-effective technology for the treatment of arsenic-containing water.
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SURFACE & COATINGS TECHNOLOGY
·
2019
·
IF 3.192
Jingcheng Du,Cailong Zhou,Zhijie Yang,Jiang Cheng,Yuanyuan Shen,Xinjuan Zeng,Luxi Tan,Lichun Dong
The economic and green synthesis of metal-organic frameworks (MOFs) is of great significance. In this work, a facile method for preparing HKUST-1 MOFs at room temperature with insoluble Cu 2 (OH) 2 CO 3 particles and film as the precursors was developed. The as-prepared HKUST-1 MOFs were characterized by using the XRD , Raman spectrum , FTIR, XPS and N 2 adsorption-desorption analyses, and the wetting property of the HKUST-1 film was also evaluated. The results demonstrated that the MOF film decorated copper mesh possesses the promising underwater superoleophobicity and underoil superhydrophobicity, with the contact angles of non-wetting liquids larger than 150°. The on-demand oil/water separation was subsequently realized through a prewetting method, obtaining the high separation efficiency up to 97%. The facile route by using solid precursors developed in this work might provide a new strategy for preparing MOFs, and the special wetting properties of the as-prepared materials could enrich the applications of MOF films as well.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 3
·514-520
·
IF 1.071
Liu Guomin,Li Yalong,Yang Shuting,Zhao Yi’an,Lu Tiancheng,Jia Wenyuan,Ji Xuan,Luo Yungang
To explore the ability of dihydroxyphenylalanine-insulin-like growth factor-1(DOPA-IGF-1) coated hydroxyapatite/poly(lactic-co-glycolic acid)(HA/PLGA) microspheres to promote the proliferation and osteoclastic differentiation of rabbit bone mesenchymal stem cells(rBMSCs), HA/PLGA microspheres with different HA content (10%, 30%, 50%, mass fraction) were prepared by electrospinning method and HA/PLGA microspheres with 50% HA were coated with IGF-1 and DOPA-IGF-1, respectively. They were co-cultured with rBMSCs, respctively. Cell counting kit-8(CCK-8) detection, confocal laser scanning microscopy(CLSM), alkaline phosphatase(ALP) detection and osteogenesis related genes COL1A1 , Runx2 and bone morphogenetic protein-2( BMP-2 ) detection were conducted to detect the proliferation activity, cell morphology, differentiation ability and the expression level of osteogenesis-related genes of cells cultured on all microspheres groups. The results showed that rBMSCs proliferation increased in an HA content dependent manner, and cells proliferated more in the IGF-1 coated and DOPA-IGF-1 coated groups, in particular in DOPA-IGF-1 coated group, and the differences were more remarkable over time ( P <0.05). HA/PLGA microspheres promoted the proliferation and osteogenic differentiation of rBMSCs, and DOPA-IGF-1 coating enhanced the proliferation and osteogenic differentiation of rBMSCs.
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EUROPEAN JOURNAL OF PHARMACOLOGY
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2019
·
IF 3.17
Qi Wan,Hui Chen,Guirun Xiong,Rui Jiao,Yun Liu,Xiaolei Li,Yu Sun,Jingcheng Wang,Lianqi Yan
Intraarticular fibrosis following knee surgery is a troublesome complication and remains a challenging problem for clinicians. Artesunate (ART), a classical anti-malarial drug extracted from the Chinese medicinal herb Artemisia annua L, has been associated with some fibrosis-related diseases. However, its effect and underlying mechanism on knee arthrofibrosis are still obscure. In the present study, we found that ART induced cellular autophagy flux and inhibited cell proliferation in fibroblasts. Intriguingly, genetic depletion of Beclin-1 abolished ART-triggered cellular autophagy and further attenuated the inhibitory effect of ART on fibroblasts proliferation. Moreover, at molecular level, our results demonstrated that ART-induced autophagy activation was associated with the inhibition of mTOR signaling through PI3K/AKT/mTOR pathway and AMPK/mTOR pathway. In vivo, ART treatment triggered autophagy activation and alleviated the severity of surgery-induced knee arthrofibrosis. Taken together, we concluded that ART exhibited anti-proliferation efficacy in fibroblasts and alleviated the severity of knee arthrofibrosis in rabbits by inducing Beclin-1-mediated autophagy via inhibition of mTOR signaling. These findings indicated that ART might be a potential therapeutic agent for preventing the progression of surgery-induced intraarticular fibrosis of knee.
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FREE RADICAL BIOLOGY AND MEDICINE
·
2019
·
IF 5.657
Ying He,Shenglan Li,Damu Tang,Yu Peng,Jie Meng,Shifang Peng,Zhenghao Deng,Sisi Qiu,Xiaohua Liao,Haihua Chen,Sha Tu,Lijian Tao,Zhangzhe Peng,Huixiang Yang
Sterile inflammation is initiated by damage-associated molecular patterns (DAMPs) and a key contributor to acute liver injury (ALI). However, the current knowledge on those DAMPs that activate hepatic inflammation under ALI remains incomplete. We report here that circulating peroxiredoxin-1 (Prdx1) is a novel DAMP for ALI. Intraperitoneal injection of acetaminophen (APAP) elicited a progressive course of ALI in mice, which was developed from 12 to 24 h post injection along with liver inflammation evident by macrophage infiltration and upregulations of cytokines (IL-1β, IL-6 and TNF-α); these alterations were concurrently occurred with a robust and progressive production of serum Prdx1. Similar observations were also obtained in carbon tetrachloride (CCl 4 )-induced ALI in mice. Removal of the source of serum Prdx1 protected mice deficient in Prdx1 from APAP and CCl 4 -induced liver injury, and decreased macrophage infiltration, IL-1β, IL-6 and TNF-α production. As a result, Prdx1 −/− mice were strongly protected from APAP-induced death that was likely progressed from ALI. Additionally, intravenous re-introduction of recombinant Prdx1 (rPrdx1) in Prdx1 −/− mice reversed or reduced all the above events, demonstrating an important contribution of circulating Prdx1 to ALI. rPrdx1 potently induced in primary macrophages the expression of pro-IL-1β, IL-6, TNF-α, and IL-1β through the NF-κB signaling as well as the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling, evident by caspase-1 activation. Furthermore, a significant elevation of serum Prdx1 was demonstrated in patients (n = 15) with ALI; the elevation is associated with ALI severity . Collectively, we provide the first demonstration for serum Prdx1 contributing to ALI.
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NANOTECHNOLOGY
·
2019
·Vol. 30
·期 48
·485706
·
IF 3.399
Feng Long,Wei Li,Wanling Chen,Danni Liu,Yue Chen,Rui Zhou,Penghui Li
In this work, a novel label-free electrochemical biosensor is developed for the detection of galectin-1 (Gal-1) based on gold nanoparticle (AuNP) loaded octahedral Cu2O (Cu2O@Au) nanocomposites. The AuNPs on the surface of the Cu2O nanocrystals not only enhance the electrochemical performance, but also serve as the binding sites for the lactose ligand which can specifically bind with Gal-1. The Cu2O@Au nanocomposites provide the synergic effect of electrochemical signal amplification and lactose–galectin reaction as the recognition strategy. Under optimal conditions, the proposed biosensor exhibits a variation of electrochemical responses to different concentrations of Gal-1 ranging from 0.1 pg ml−1 to 10 ng ml−1. This work presents an alternative electrochemical biosensor for the detection of tumor biomarkers based on a simple and economical lactose ligand incorporated Cu2O@Au biosensor platform.
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EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2018
·Vol. 2018
·期 8
·1047-1052
·
IF 2.507
Xiaoxia Jia,Ning Yuan,Li Wang,Jiangfeng Yang,Jinping Li
Graphical Both high selectivity and adsorption capacity in the adsorptive separation of CO 2 , CH 4 , and N 2 were achieved by means of (CH 3 ) 2 NH functionalization of the unsaturated metal sites of the MOF Ni-HKUST-1. Ni-HKUST-1, with the same topological structure as Cu-BTC (HKUST-1), was synthesized by a (CH 3 ) 2 NH-assisted method. Ni-HKUST-1 with high purity (> 90 %), yield (85 %), and BET surface area (1088 m 2 /g) was successfully synthesized for the first time by using NiCl 2 . The pure-component adsorption isotherms of CO 2 , CH 4 , and N 2 on Ni-HKUST-1 were measured by the volumetric method and the data used to estimate the separation selectivity for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 binary mixtures according to the ideal adsorbed solutions theory. At 273 K and 1 atm, the selectivities for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 were 14.49, 5.36, and 183.41, respectively, and the adsorption capacities for CO 2 and CH 4 were 223.87 and 67.89 cm 3 /g, respectively. This is a rare demonstration of both high selectivity and adsorption capacity in the separation of CO 2 , CH 4 , and N 2 .
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Xiubing Huang,Jie Feng,Hassan R.S. Abdellatif,Jing Zou,Guan Zhang,Chengsheng Ni
Mn-substituted double perovskites , PrBaCo 2-x Mn x O 5+δ (x = 0, 0.5, 1), are evaluated as cathode materials for intermediate-temperature solid oxide fuel cells. The effects of Mn substitution content on their structural and electrochemical properties including crystal structure, thermal expansion coefficient , and cathodic interfacial polarization resistance are investigated. The PrBaCo 2-x Mn x O 5+δ samples exhibit structural changes with increasing Mn contents from tetragonal (x = 0) to cubic (x = 0.5 and 1.0) symmetry. The thermal expansion coefficient decreases with the increasing Mn content while the cathodic performance increases with the increment of Mn content from x = 0 to x = 0.5 then decreases with the further increment of Mn content from x = 0.5 to x = 1.0. When using La 0.8 Sr 0.2 Ga 0.8 Mg 0.15 Co 0.05 O 3 with 300 μm thickness as electrolyte and Sr 2 Fe 1.4 Ni 0.1 Mo 0.5 O 6-δ as anode, the maximum powder density of the x = 0.5 composite is 0.638 W cm −2 , which is higher than that of the other two samples with x = 0 (0.474 W cm −2 ) and x = 1.0 (0.371 W cm −2 ) at 800 °C.
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危险品化学品经营许可证（带存储）