ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2018
·
IF 3.974
Shi-Weng Li,Xiao-Ying Zeng,Yan Leng,Lin Feng,Xiao-Hu Kang
In vitro experiments were performed to determine whether auxin can mediate the formation of adventitious roots in response to heavy metal and drought stresses using a model rooting plant, mung bean [ Vigna radiata (L.) Wilczek]. The treatments with CdCl 2 or mannitol alone significantly inhibited the formation and growth of adventitious roots in mung bean seedlings. In contrast, when CdCl 2 or mannitol was applied together with indole-3-butyric acid (IBA), IBA considerably cancelled the inhibition of adventitious rooting by stresses. Treatment with CdCl 2 or mannitol alone significantly increased the soluble protein and malondialdehyde (MDA) contents. CdCl 2 and mannitol stress each induced differentially significant changes in the activities of antioxidative enzyme and antioxidant levels during adventitious rooting. Notably, both CdCl 2 and mannitol stress strongly reduced the peroxidase (POD) and ascorbate peroxidase (APX) activities and glutathione (GSH) and phenols levels. Catalase and superoxide dismutase (SOD) activity were enhanced by CdCl 2 but reduced by mannitol. CdCl 2 increased the ascorbate acid (ASA) level, which was decreased by mannitol. Furthermore, when CdCl 2 or mannitol was applied together with IBA, IBA counteracted the CdCl 2 - or mannitol-induced increase or decrease in certain antioxidants, MDA, and antioxidative enzymes. These results suggest that Cd and mannitol stress inhibition of adventitious rooting is associated with the regulation of antioxidative enzymes and antioxidants in cells to defense the oxidative stress . Moreover, IBA alleviates the effects of Cd and mannitol stress on the rooting process partially through the regulation of antioxidative defense systems.
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高影响因子
JOURNAL OF CHEMICAL RESEARCH
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2018
·
IF 0.668
Song Bai,Shan Liu,Yunying Zhu,Jiali Lu,Lina Ai,Jing Xue,Qin Wu
An efficient asymmetric synthesis of chiral β-amino acid ester derivatives containing a 4-(pyridin-3-yl)pyrimidin-2-yl amine moiety was developed. This catalytic asymmetric Mannich reaction gave target products in high yields (95%) and excellent enantioselectivities (>99% ee) using a cinchona-based squaramide catalyst under solvent-free, one-pot conditions. Antiviral bioassays indicated that some of the chiral products exhibited higher antiviral activities against tobacco mosaic virus than the commercial compound ribavirin.
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JOURNAL OF ORGANOMETALLIC CHEMISTRY
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2016
·
IF 2.336
Kun Liu,Kai-Kai Liu,Mu-Jeng Cheng,Ming-Han Han
A combined experimental and theoretical study was conducted to investigate the isomerization of 2-methyl-3-butenenitrile (2M3BN) to 3-pentenenitrile (3PN) and to 2-methyl-2-butenenitrile (2M2BN) catalyzed by nickel diphosphine complexes. Ni(1,4-bis(diphenylphosphino)butane) (dppb) was identified as the most reactive catalyst among the complexes that we examined experimentally. Quantum mechanics (density functional theory) was then used to study the two isomerization mechanisms catalyzed by this complex. We find that for the 2M3BN → 3PN isomerization, the reaction is initiated with C CN bond cleavage, followed by an allyl direct rotation and C CN bond reformation. For the 2M3BN → 2M2BN isomerization, the most energetically favorable pathway begins with C H bond activation, followed by a π-σ-σ-π allyl rearrangement and C H bond reformation. Our proposed mechanism for the 2M3BN → 2M2BN isomerization is slightly different (yet energetically more favorable) than that described in previous studies, where it has been suggested that 2M2BN is obtained through a π-σ-σ allyl rearrangement rather than a π-σ-σ-π type rearrangement. Additionally, we investigated the effect of Lewis acids in the 2M3BN → 3PN isomerization, which has been shown in most experiments to attenuate the reaction. Notably, our calculations indicated that ZnCl 2 , which is used as a model Lewis acid, actually reduces the barriers for all elementary steps. However, the effective kinetic barrier for the isomerization increases from 23.7 (without ZnCl 2 ) to 24.0 kcal/mol because of the formation of a very stable Ni(π-allyl) (CN ZnCl 2 ) intermediate, causing a decrease in the reaction rate. This theoretical result was further confirmed by our own experiments.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 5
·761-765
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IF 0.875
Sun Weizhi,Yu Shitao,Xian Mo
To investigate the green trinitration method of aromatic compounds, with Lewis acid/ionic liquid as catalyst and HNO 3 /Ac 2 O as nitration reagent, a Lewis acid/ionic liquid/HNO 3 /Ac 2 O system was established. In various combinations of Lewis acids and ionic liquids, Bi(NO 3 ) 3 ·5H 2 O/[HMIM]ClO 4 proved to be a very efficient catalyst for the trinitration of activated aromatic compounds and reusable for 3 times. Reaction conditions for the trinitration were optimized and yields of the trinitro products were from mild to excellent. This sulfuric acid-free system has the advantages of strong trinitration ability, low environment pollution, low toxicity, low cost and high potential for industrial application.
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Materials
·
2020
·Vol. 13
·期 24
·5733
·
IF 3.057
Tiancheng He,Caihuan Lv,Wenhao Li,Guohua Huang,Zhihui Hu,Jianmei Xu
The electronics related to the fifth generation mobile communication technology (5G) are projected to possess significant market potential. High dielectric constant microwave ceramics used as filters and resonators in 5G have thus attracted great attention. The Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) ceramic system has aroused people’s interest due to its underlying excellent microwave dielectric properties. In this paper, the relationships between the dielectric constant, Nd-doped content, sintering temperature and the density of Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) ceramics were studied. The linear regression equation was established by statistical product and service solution (SPSS) data analysis software, and the factors affecting the dielectric constant have been analyzed by using the enter and stepwise methods, respectively. It is found that the model established by the stepwise method is practically significant withY= −71.168 + 6.946x1+ 25.799x3, whereY,x1andx3represent the dielectric constant, Nd content and the density, respectively. According to this model, the influence of density on the dielectric constant is greater than that of Nd doping concentration. We bring the linear regression analysis method into the research field of microwave dielectric ceramics, hoping to provide an instructive for the optimization of ceramic technology.Keywords:microwave dielectric ceramics;Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) system;dielectric constant;linear regression analysis
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
·
IF 9.7
Min Xie,Xiaoying Li,Yufan Chen,Xiangyue Liao,Qiaoji Zheng,Heng Zhang,Kwok-Ho Lam,Dunmin Lin
Sodium superionic conductor (NASICON)-type phosphates cathodes have attracted considerable attention due to their high operational voltage and robust three-dimensional (3D) framework; however, the poor intrinsic electronic conductivity and low energy density hinder their broader application. Herein, a novel NASICON-type Na 3 V 1.44 Fe 0.5 Mo 0.06 (PO 4 ) 3 cathode was designed through Fe/Mo dual-doping at the V sites of Na 3 V 2 (PO 4 ) 3 and synthesized via a conventional high-temperature solid-state method. The introduction of Fe 3+ activates the V 4+ /V 5+ redox couple at a high voltage plateau (∼ 4.0 V), while also generates additional Fe 2+ /Fe 3+ and V 4+ /V 5+ redox pairs. Meanwhile, the doing of Mo 6+ creates cation vacancies, effectively modulating the electronic structure of vanadium and promoting ionic transport kinetics. Benefiting from this dual-doping strategy, the Na 3 V 1.44 Fe 0.5 Mo 0.06 (PO 4 ) 3 cathode delivers a high capacity of 123.4 mAh g −1 at 0.2C and an impressive energy density of 406 Wh kg −1 within 2.2–4.2 V. Moreover, it exhibits outstanding cycling stability, presenting a capacity retention of 92 % after 2500 cycles at 30C. This work highlights a viable strategy for advancing high-performance NASICON-type cathodes through complex metal ion doping.
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高影响因子
Food & Function
·
2013
·Vol. 4
·期 11
·1609-1616
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IF 2.694
Yi Zhang,Ying Wang,Baodong Zheng,Xu Lu,Weijing Zhuang
Prebiotics such as oligosaccharides, fructans, and resistant starch (RS) stimulate the growth of beneficial bacteria in large bowel and modify the human gastrointestinal environment. In this study, compared with glucose (GLU) and high amylose maize starch (HAMS), the in vitro effects of LRS3 and P-LRS3 (RS3 and purified RS3 prepared from lotus seed starch) on the proliferation of bifidobacteria were assessed by assessing the changes in optical density (OD), pH values, short chain fatty acid (SCFA) production, and tolerance ability to gastrointestinal conditions. Significantly higher OD values were obtained from media containing LRS3 and P-LRS3, and especially in the medium containing P-LRS3, the OD value of which reached 1.36 when the concentration of the carbon source was 20 g L−1. Additionally, the lag phase of bifidobacteria was 8 h in the medium with LRS3 or P-LRS3, whereas it was 16 h in the medium with GLU or HAMS. What is more, a higher content of butyric acid was obtained in the P-LRS3 medium. Compared with GLU and HAMS media, bifidobacteria had a higher tolerance to gastrointestinal conditions in LRS3 and P-LRS3 media. It shows that lotus seed resistant starch, especially P-LRS3, could stimulate the growth of bifidobacteria. The rough surface of resistant starch and the SCFAs produced during fermentation might influence the proliferation of bifidobacteria.
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高影响因子
CyTA-Journal of Food
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2025
·
IF 1.7
Han Zhao,Xiaohui Duan,Siqi Xie,Lili Cheng,Fei Wang,Wenjuan Xu,Yaolei Zhang,Weiyi Zhang,Cheng Zhao
Listeria monocytogenes is a foodborne pathogenic bacterium that can survive under a wide range of temperature and pH conditions, with a mortality rate of up to 20% −30%. One emerging and validated method of indirectly assessing Listeria monocytogenes in food is detecting 3-hydroxy-2-butanone gas. In this study, WO3 nanoflowers (a diameter of 2.8 µm) and two different hierarchical structures of WO3 were successfully synthesized. XRD, BET, SEM, and TEM were applied to characterize their morphology, microstructure, catalytic structure, and specific surface area. For assessing their gas sensing performances toward 3-hydroxy-2-butanone, a series of gas sensitivity indicators were purposefully measured. The results indicated that WO3 nanoflowers had the best gas sensing performance including high sensitivity (81 @ 20 ppm), rapid response-recovery time (4 s/9 s), low LOD (1 ppm) and good stability. Moreover, by analysing the various characterization results of these materials, the sensitivity mechanism was explained in detail as well.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Kunqi Liu,Junxia Wang,Jin Wang,Die Liu,Youqin Huang,Zhenjin Fu,Xi Zhang
In this study, the novelly designed Sr 0.5 Zr 2 (PO 4 ) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics were utilized as nuclear waste form to simultaneously immobilize simulated fission products Sr and actinide nuclides. The phase transition mechanism, thermokinetics and densification behavior of Sr 0.5 Zr 2 (PO 4 ) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics based on in-situ synthesis were systemically analyzed by XRD, in-situ XPS, TG-DSC, SEM and density measurements. The results demonstrate that the formation of Ce 0.5 Sm 0.5 PO 4 solid solution phase preceded that of Sr 0.5 Zr 2 (PO 4 ) 3 phase, of which there is a valence change of Ce from Ce 4+ to Ce 3+ before 1023 K. Additionally, as for the exothermic crystallization enthalpy, change of exothermic crystallization enthalpy and activation energy, the values of Sr 0.5 Zr 2 (PO 4 ) 3 and Ce 0.5 Sm 0.5 PO 4 phases in composite ceramics are 286.17 – 515.61 mJ, 19.11 – 35.38 J/g, 702.45 kJ/mol and 145.21 – 232.44 mJ, 9.26 – 15.44 J/g, 450.04 kJ/mol, respectively. It is then indicated that the formation of Ce 0.5 Sm 0.5 PO 4 phase is definitely more favorable than that of Sr 0.5 Zr 2 (PO 4 ) 3 phase. Simultaneously, the relative densities of Sr 0.5 Zr 2 (PO 4 ) 3 –Ce 0.5 Sm 0.5 PO 4 composite ceramics are more than 95 % when the sintering temperature exceeds 1273 K.
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高影响因子
IMMUNOLOGIC RESEARCH
·
2024
·
IF 3.3
Su Xiaoran,Wang Xinliu,Zhang Xin,Sun Yajie,Jia Yugai
Massive evidence shows that intestinal tryptophan metabolites affected by intestinal flora can modulate the progression of rheumatoid arthritis (RA). However, the effects and mechanisms of intestinal tryptophan metabolites on RA are not yet detailed. Herein, we investigated the protective effects of intestinal tryptophan metabolites on RA and its detailed mechanisms. In this study, the collagen-induced arthritis (CIA) rat model was established. Based on metabolomics analysis, the contents of β-indole-3-acetic acid (IAA), indolylpropionic acid, and indole-3-β-acrylic acid in the sera of CIA rats were significantly less compared with those of the normal rats. Under the condition of Treg or Th17 cell differentiation, IAA significantly promoted the differentiation and activation of Treg cells instead of Th17 cells. Intestinal tryptophan metabolites are well-known endogenic ligands of aryl hydrocarbon receptor (AhR). Not surprisingly, IAA increased the level of Foxp3 through activating the AhR pathway. Interestingly, IAA had little impact on the level of Foxp3 mRNA, but reducing the ubiquitination and degradation of Foxp3. Mechanically, IAA reduced the expression of the transcriptional coactivator TAZ, which was almost completely reversed by either AhR antagonist CH223191 or siRNA. In vitro, IAA decreased the combination of TAZ and the histone acetyltransferase Tip60, while it increased the combination of Tip60 and Foxp3. In CIA rats, oral administration of IAA increased the number of Treg cells and relieved the inflammation. A combined use with CH223191 almost abolished the effect of IAA. Taken together, IAA attenuated CIA by promoting the differentiation of Treg cells through reducing the ubiquitination of Foxp3 via the AhR-TAZ-Tip60 pathway.
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高影响因子
Science Bulletin
·
2023
·
IF 18.9
Along Zhao,Fangjie Ji,Changyu Liu,Shihao Zhang,Kean Chen,Weihua Chen,Xiangming Feng,Faping Zhong,Xinping Ai,Hanxi Yang,Yongjin Fang,Yuliang Cao
Fe-based polyanionic sulfate materials are one of the most promising candidates for large-scale applications in sodium-ion batteries due to their low cost and excellent electrochemical performance. Although great achievements have been gained on a series of Na 6−2 x Fe x (SO 4 ) 3 (NFSO- x , 1.5 ≤ x ≤ 2.0) materials such as Na 2 Fe 2 (SO 4 ) 3 , Na 2 Fe 1.5 (SO 4 ) 3 , and Na 2.4 Fe 1.8 (SO 4 ) 3 for sodium storage, the phase and structure characteristics on these NFSO- x are still controversial, making it difficult to achieve phase-pure materials with optimal electrochemical properties. Herein, six NFSO- x samples with varied x are investigated via both experimental methods and density functional theory calculations to analyze the phase and structure properties. It reveals that a pure phase exists in the 1.6 ≤ x ≤ 1.7 region of the NFSO- x , and part of Na ions tend to occupy Fe sites to form more stable frameworks. The NFSO-1.7 exhibits the best electrochemical performance among the NFSO- x samples, delivering a high discharge capacity (104.5 mAh g −1 at 0.1 C, close to its theoretical capacity of 105 mAh g −1 ), excellent rate performance (81.5 mAh g −1 at 30 C), and remarkable cycle stability over 10,000 cycles with high-capacity retention of 72.4%. We believe that the results are useful to clarify the phase and structure characteristics of polyanionic materials to promote their application for large-scale energy storage.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 32
·期 10
·2110335
·
IF 18.808
Hu Li,Limei Lin,Liquan Yao,Fengying Wu,Dong Wei,Guoliang Liu,Zhigao Huang,Shuiyuan Chen,Jianmin Li,Guilin Chen
MXene, a class of 2D materials of metal carbide or nitride, has attracted a lot of attention recently due to its excellent optical and electrical properties. In this work, titanium-carbide MXene (Ti 3 C 2 T x ) is introduced as a back electrode in Sb 2 (S,Se) 3 thin-film solar cells (FTO/CdS/Sb 2 (S,Se) 3 /MXene) for the first time, which displaces traditional carbon (C) and gold (Au) electrodes entirely. Impressively, thanks to its high conductivity, mild reflectivity, and flexible flake architecture, the MXene-based device performance outperforms typical C and Au electrodes by 153% and 77%, respectively. Specifically, the tunable work function of MXene and a beneficial Sb–O bond formed between Sb 2 (S,Se) 3 and MXene efficiently suppress the recombination and enhance charge transport by enjoying the unique merit of the rich terminal groups of MXene. As a result, the best efficiency of 8.29% of MXene-based Sb 2 (S,Se) 3 solar device is achieved, which represents the highest performance of noble metal and/or hole transport layer-free derived Sb 2 (S,Se) 3 solar cells to date. This result has revealed that MXene is a feasible material to substitute the back electrode in Sb-based solar cells to reach high efficiency, low cost, and high stability.
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