JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Xingchuan Yang,Huanxin Li,Chunmei Cao,Li Xu,Guoji Liu
Liquid-liquid equilibria (LLE) data for ternary systems of water + 1,6-hexanediol + 1-pentanol/ 3-methyl-1-butanol/ 2-methyl-2-butanol were measured at (293.15, 303.15, 313.15 and 323.15) K under 101.3 kPa. Cloud-point method was applied to determine the solubility curves data. Distribution coefficient and separation factors for 1,6-hexanediol were calculated from the measured tie-line data to evaluate the extraction effect of alcohols on 1,6-hexanediol. The reliability of experimental LLE data were tested by Othmer–Tobias equation and Hand equation, NRTL and UNIQUAC models were applied to correlate the measured data and the calculated results show that both models can fit the experimental data very well.
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 3
·901-908
·
IF 2.482
Wu Yuting,Yang Long,Wu Bo,Li Jie,Liu Binyao,Ke Gaili,Dong Faqin,Zhou Yong,He Huichao
It has been reported that β -MnO 2 has photocatalytic activity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. Nevertheless, it is hard to exclude the possibility that the oxidative-coupling of 2-naphthols is initiated by β -MnO 2 catalysis in dark due to the insufficient investigations in the related reports. In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols with different phases MnO 2 catalysis in dark and under visible-light irradiation were systematically investigated. The results revealed that the oxidative-coupling of 2-naphthols is jointly initiated by MnO 2 catalysis and O 2 -oxidation, not by MnO 2 photocatalysis. Among the α -MnO 2 , β -MnO 2 , γ -MnO 2 and δ -MnO 2 catalysis, β -MnO 2 catalysis has the optimal performance, its selectivity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols is close to 100%, and its catalytic capacity could be well retained after multiple using. Our findings provide comprehensive and accurate understanding the catalytic role of MnO 2 for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. Graphic In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols was proved to be jointly initiated by MnO 2 catalysis and O 2 -oxidation, not by MnO 2 photocatalysis. β -MnO 2 has the optimal catalytic activity for the oxidative-coupling of 2-naphthols relative to α -MnO 2 , γ -MnO 2 and δ -MnO 2 .
研究领域:
催化化学
·
有机合成
·
材料化学
·
物理化学
·
纳米催化
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2020
·
IF 3.209
Youxi Jin,Yu Pan,Biao Jin,Dongri Jin,Chunbo Zhang
(S)-1-(5-(4-Methylpiperazin-1-yl)-2,4-dinitrophenyl)pyrrolidine-2-carboxylic acid (Pro-PPZ) was employed as a chiral derivatization reagent (CDR) for the efficient enantioseparation and ultrasensitive mass spectrometric detection of chiral amines. Pro-PPZ was prepared from the one-step reaction of 1-(5-fluoro-2,4-dinitrophenyl)-4-methylpiperazine (PPZ) and l -proline. Two amines and two amino acid methyl esters were selected as model chiral amines, which were easily labeled with Pro-PPZ under mild reaction conditions (35 °C for 10 min) generating Pro-PPZ-amine derivatives. The resulting diastereomers were completely separated by reversed-phase liquid chromatography (RP-LC) using an ODS column ( R s = 3.4–17.0 for amines). Ultrasensitive detection limits on femtomolar level were obtained for the tested amines using multiple reaction monitoring (MRM) chromatograms at a single monitoring ion, m/z 289 (0.1–5.0 fmol for amines). The practical metabolite analysis of (R)-1-aminoindan (R-AI) in saliva samples was performed by LC–MS/MS using the Pro-PPZ derivatization method. The method was validated in terms of precision, accuracy, and linearity. Using this method, R-AI concentrations in saliva were determined after a single oral administration of the drug rasagiline to healthy male and female subjects, but no (S)-1-aminoindan (S-AI) was detected, which suggesting that R-AI was not converted into S-enantiomer in the metabolic process. R-AI concentrations in four healthy volunteers ranged from 32.85 nM to 49.45 nM, with an average value of 43.76 nM. To date, there is no LC–MS (or MS/MS) method reported for the enantioselective determination of R-AI in human saliva samples.
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ADVANCED POWDER TECHNOLOGY
·
2021
·
IF 4.833
Chuanqiang Li,Xiang Liu,Haobo Wang,Yang He,Liyun Song,Yudi Deng,Shangchen Cai,Shimin Li
A cobalt-based metal–organic framework was used as a precursor to synthesize Co 3 O 4 catalysts exhibiting a hexagonal layered morphology by calcination at varying temperatures. Various characterization techniques, such as XRD, SEM, Raman, H 2 -TPR, O 2 -TPD and N 2 adsorption–desorption, were used to study the effects of calcination temperature on the grain size, surface area, and pore volume of the catalysts. The Co 3 O 4 catalyst obtained by calcination at 350 °C (Co 3 O 4 -350) exhibited the highest catalytic activity for the total oxidation of propane. Furthermore, the small grain size and layered structure of Co 3 O 4 -350 allowed it to possess a high specific surface area, a highly exposed {1 1 2} facets, and abundant oxygen defects that facilitated a favorable low-temperature reducibility and oxygen mobility, thereby improving catalytic activity. This research offers a simple strategy for synthesis of Co 3 O 4 with layered structure, highly exposed {1 1 2} facets and rich oxygen defects.
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产品关联
DOI
高影响因子
ELECTROANALYSIS
·
2021
·Vol. 34
·期 2
·263-274
·
IF 3.223
Minling Ding,Qi Shu,Nan Zhang,Chaoren Yan,Huizhe Niu,Xiaoqian Li,Ping Guan,Xiaoling Hu
The amyloid-β peptide (1–42) (Aβ 42 ) can provide high diagnostic accuracy for the early diagnosis of Alzheimer's disease (AD). In this study, an immunosensor based on the peroxidase-like activity of heme-Aβ 42 was designed for Aβ 42 detection. The glassy carbon electrode (GCE) was electrodeposited Au particles (GCE/Au). The GCE/Au was modified using polythionine-methylene blue (PTH−MB), AuNPs, monoclonal antibody (anti-Aβ 42 ), and bovine serum albumin (BSA), successively. The GCE/Au/PTH−MB/AuNPs/anti-Aβ 42 /BSA could competitively recognize Aβ 42 and heme-Aβ 42 . The anchored heme-Aβ 42 showed strong electrocatalytic activity between H 2 O 2 and ferrocenemethanol. Under optimum conditions, we determined detection limits of 17.3 pM in PBS pH 7, 25.2 pM in serum, and 23.8 pM in saliva. The recovery ranged from 71.0 % to 117.8 %.
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DOI
高影响因子
Molecular Medicine Reports
·
2020
·Vol. 21
·期 6
·2466-2474
·
IF 2.1
Lu Wang,Liran Zhu,Chenfangyuan Duan,Lu Li,Guangliang Chen
Total saponins extracted from Dioscorea collettii (TSD), extracts of the Chinese herb Dioscorea, are thought to exhibit therapeutic benefit in gouty arthritis. However, its exact mechanism remains unclear. The current study aimed to elucidate the underlying mechanisms by investigating the effects of TSD on the inflammation induced by monosodium urate (MSU) crystals in THP‑1 macrophages. The viability of THP‑1 macrophages was examined using the MTT assay and the levels of inflammatory cytokines, including interleukin (IL)‑1β, IL‑18 and tumor necrosis factor (TNF)‑α, released by the cells were quantitatively measured using ELISA kits. The results revealed that the protein level of cluster of differentiation 11b increased in THP‑1 cells treated with 100 ng/ml phorbol ester, suggesting that monocytic THP‑1 cells were successfully differentiated into macrophages. TSD decreased the levels of inflammatory cytokines, including TNF‑α, IL‑18 and IL‑1β, secreted by THP‑1 macrophages. As the release of IL‑1β and IL‑18 is dependent on the NLR family pyrin domain containing 3 (NALP3) inflammasome and caspase‑1, the current study investigated the effect of TSD on the aforementioned proteins. The results revealed that TSD decreased the protein levels of NALP3 and apoptosis‑associated speck‑like, which serve important roles in the assembly of the NALP3 inflammasome. Furthermore, NALP3 inflammasome‑related proteins were also decreased by TSD in rotenone induced THP‑1 macrophages, TSD inhibited the activation of caspase‑1 and rotenone‑induced NALP3 inflammasome activation in THP‑1 macrophages. The results obtained in the current study revealed that TSD attenuated MSU crystal‑induced inflammation by inhibiting rotenone‑induced activation of the NALP3 inflammasome and caspase‑1, suggesting that these two proteins may be novel targets for the treatment of gouty arthritis.
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Mengqi Wang,Bo Chen,Yan He,Zhili Li,Yuanyuan Ge
Titanium silicalite-1 zeolite (TS-1) has been widely used as a catalyst for the epoxidation of 1-hexene. However, fast synthesis of TS-1 with high activity and stability remains a great challenge. In this study, a new strategy using sodium persulfate (SPS) as a crystallization modifier was proposed for the accelerated synthesis of anatase-free TS-1. The anatase-free TS-1 (TS-20-SPS) could be obtained after 20 h of hydrothermal crystallization. TS-20-SPS had a low Si/Ti ratio (31) and achieved a high conversion (20 %) in the epoxidation of 1-hexene at room temperature (298 K), which was 200 % higher than that of TS-1 synthesized without adding SPS. The addition of SPS not only accelerated the crystallization due to the generation of ·OH, but also reduced the pH value of the system to avoid the generation of anatase. This SPS-assisted approach offers an avenue for the accelerated synthesis of high-performance, anatase-free TS-1.
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高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Qingcun Li,Qingsheng Bai,Ronggang Zheng,Peng Li,Rui Liu,Sujuan Yu,Jingfu Liu
Micro- and nanoplastics (MNPs) have drawn growing concerns because of their potential adverse effects on aquatic ecosystems. However, limited information is available regarding their concentration and distribution in the actual environment, particularly for nanoplastics (NPs). Herein, forty-eight sampling sites were established across the entire Taihu Lake to comprehensively investigate small MNP (<100 μm) pollution. By pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), six kinds of MNPs in Taihu Lake, namely polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA) were quantified. Total mass concentrations of the six MNPs in the collected surface water samples ranged from 381 to 1356 μg/L. Specifically, the concentrations of small microplastics (1–100 μm) ranged from 229 to 1182 μg/L, and those of nanoplastics (<1 μm) ranged from 88 to 305 μg/L. The mass concentrations of the six MNPs were as follows: 20.3–635.7 μg/L for PE, 46.6–281.4 μg/L for PP, 81.8–410.6 μg/L for PET, 62.8–445.8 μg/L for PVC,
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DOI
PubMed
高影响因子
TETRAHEDRON-ASYMMETRY
·
2014
·
IF 2.165
Rui-Jie Chen,Gao-Wei Zheng,Yan Ni,Bu-Bing Zeng,Jian-He Xu
A new NADH-dependent carbonyl reductase Rh CR capable of efficiently reducing the ε-ketoester ethyl 8-chloro-6-oxooctanoate (ECOO) to give ethyl ( S )-8-chloro-6-hydroxyoctanoate [( S )-ECHO], an important chiral precursor for the synthesis of ( R )-α-lipoic acid, was identified from Rhodococcus sp. ECU1014. Using recombinant Escherichia coli cells expressing Rh CR and glucose dehydrogenase used for the regeneration of cofactor, 440 g L −1 (2 M) of ECOO were stoichiometrically converted to ( S )-ECHO in a space–time yield of 1580 g L −1 d −1 without the external addition of any expensive cofactor.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Tong-Yang Song,Zhao-Xia Dong,Jian-Dong Song,Xiao-Xia Wang,Guan-Qun Xie,Meng-Fei Luo,Ji-Qing Lu
Dehydrochlorination of 1, 1, 2-trichloroethane was performed on SiO 2 supported alkali metal (Na. K, Cs) and transition metal (Mn, Ni, Zn) catalysts. The surface basicity or acidity of the catalyst exerted great influence on catalytic behaviors. The catalysts with higher amount of base or acid sites resulted in higher activity due to more adsorption sites for reactant. The basic catalysts (Cs/SiO 2 and K/SiO 2 ) tended to form vinylidene chloride with a selectivity up to 80 %; the neutral catalysts (Na/SiO 2 and SiO 2 ) tended to form 1, 2-dichloroethene with a selectivity up to about 80 %; the acidic catalysts (Zn/SiO 2 , Mn/SiO 2 and Ni/SiO 2 ) tended to form 1, 2-dichloroethene with a selectivity up to 96 %. Proposed reaction mechanisms included an E1cb mechanism with a carbanion intermediate on the basic catalysts, an E2 concerted mechanism on the neutral catalysts, and an E1 mechanism with a carbonium intermediate on the acidic catalysts.
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高影响因子
MATERIALS LETTERS
·
2013
·
IF 2.224
Kejie Yu,Xuebin Zhang,Hongwu Tong,Xiangyan Yan,Shaomin Liu
Fibrous monodisperse core–shell structured Fe 3 O 4 /SiO 2 /KCC-1 nanoparticles were synthesised successfully through a surfactant-templated microemulsion formation process. The structure and morphology of the synthesised nanoparticles were investigated by scanning electron microscopy , transmission electron microscopy , superconducting quantum interference device susceptometer, X-ray diffraction, thermogravimetric analysis and N 2 adsorption/desorption. These nanoparticles showed monodisperse spherical morphology, high magnetism , good thermal stability , large surface area , direct channels, easily accessible large pores and narrow size distribution. A mechanism for the synthesis of these nanoparticles was proposed and explained. Adsorption experiments indicated that the as-prepared materials had good adsorption capacity for dye and could perform a fast transfer of molecules, indicating its promising application in purification of industrial wastewater, drug delivery and so on.
研究领域:
纳米医学
·
材料科学
·
环境工程
·
生物材料
·
药剂学
·
胶体与界面化学
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高影响因子
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
·
2012
·Vol. 85
·期 4
·481-486
·
IF 1.436
Li Rong,Pan Chunyue,Xiong Shaohui,Yu Guipeng,Wang Pingshan,Zou Yingping,Zhang Aiqing
Tetrakis(1-adamantanecarboxymethyl)methane was prepared by indirect esterification. DSC traces of tetrakis(1-adamantanecarboxymethyl)methane showed two endothermic peaks. Entropy ratio of these two peaks is: ΔStrs/ΔSfus = 1.58 > 1. XRD confirmed the solid–solid transition and analysis of XRD by DICVOL demonstrated tetrakis(1-adamantanecarboxymethyl)methane is a new compound with a highly disordered crystalline phase. Analysis of entropy changes at transitions showed why fusion entropy (ΔSfus = 70.07 J mol−1 K−1) of tetrakis(1-adamantanecarboxymethyl)methane is much larger than Timmermans’ criterion.
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高影响因子
危险品化学品经营许可证（带存储）