LWT-FOOD SCIENCE AND TECHNOLOGY
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2019
·
IF 3.714
Xiaosan Wang,Cong Jiang,Wendi Xu,Zhicheng Miu,Qingzhe Jin,Xingguo Wang
Structured triacylglycerols (TAGs), rich in 1,3-dioleoyl-2-palmitoylglycerol (OPO) and 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL), were prepared by enzymatic acidolysis of fractionated palm stearin with free fatty acids . The effects of enzyme type, substrate molar ratio, enzyme load, temperature, and reaction time on the yields of OPO and OPL, palmitic acid (PA) content at the sn- 2 position of TAG, and the percentage of PA at the sn- 2 position relative to total PA content were investigated. Under optimal reaction conditions (palm stearin/oleic acid/linoleic acid molar ratio of 1:8:4, lipase NS 40086 loading of 8%, 60 °C, 4 h), the combined yields of OPO and OPL was 69.26%, PA content at the sn- 2 position reached 87.75%, and the relative percentage of PA at the sn- 2 position was up to 71.07%. The synthesized TAGs have potential to be used in infant formulas.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Wenbo Zhu,Yongzhong Jia,Jinhe Sun,Pengrui Zhang,Fei Shao,Yan Jing
A novel synergistic extraction system was studied for the separation of lithium isotopes using lithium salts solution as aqueous phase and dichloromethane containing 4′-acetylbenzo-15-crown-5 and [BMIm][NTf 2 ] as organic phase with solvent extraction method . The key factors such as anions of lithium salts, concentrations of LiNTf 2 , initial pH values of aqueous phase, solvents, volume ratio of dichloromethane and [BMIm][NTf 2 ] were investigated in this study. Results showed that the maximum extraction rate of lithium was 68.36% and the maximum single stage separation factor of 6 Li and 7 Li was 1.056 ± 0.002. The formed complex in organic phase was studied by the slope analysis method, which indicated that the complex was composed of Li-ion and 4′-actylbenzo-15-crown-5 by 1:1. The thermodynamic parameters of the 6 Li and 7 Li exchange reaction were calculated by data obtained on temperature during experiments, which explained that the exchange behavior of 6 Li and 7 Li in this system was a spontaneous exothermic reaction . In addition, this system was able to efficiently separate lithium isotopes at lower temperature.
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高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2019
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IF 3.218
Haiyan Jia,Taotao Yang,Quan Xu,Jingkun Xu,Limin Lu,Yongfang Yu,Ping Li
In this paper, core-shell structured poly (indole‑5‑carboxylic acid) @ poly (3, 4‑ethylenedioxythiophene) (PIn‑5‑COOH@PEDOT) composite was prepared by a facile two-step chemical oxidation method. The composite possesses large specific surface area, high stability, good electrical conductivity and redox activity, which was designed as label-free electrochemical immunosensing platform for the monitor of the prostate specific antigen (PSA). In this sensing system, PIn-5-COOH served as both signal molecule and antibody carrier. The coating PEDOT was used to enhance the conductivity and stability of PIn-5-COOH. Benefiting from the synergistic effects between PIn-5-COOH and PEDOT, the fabricated immunosensor exhibited a wide linear range of 0.01–25 ng mL −1 and low detection limit of 3.4 pg mL −1 (S/N = 3) for the assay of PSA, coupled with good selectivity, reproducibility and stability. The immunosensor is simple, sensitive, specific and reproducible, which could provide a potential approach for clinical diagnosis.
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高影响因子
JOURNAL OF CATALYSIS
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2018
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IF 6.759
Qifan Wu,Bin Zhang,Chao Zhang,Xiangchun Meng,Xinluona Su,Shan Jiang,Ruhui Shi,Yan Li,Weiwei Lin,Masahiko Arai,Haiyang Cheng,Fengyu Zhao
The selectivity of 3-nitrostyrene (NS) hydrogenation over 0.5 wt-% Pt catalysts supported on carbon materials can be switched simply by changing reduction temperature. When the reduction temperature was 150 °C, 1-ethyl-3-nitrobenzene (ENB) was mainly produced in a selectivity of 93% at a conversion of 95% (at 100 °C). When the reduction was conducted at a higher temperature of 450 °C, in contrast, the main product was switched to 3-aminostyrene (AS) in a selectivity of 96% at a conversion of 91%. That is, the Pt/C catalysts reduced at low and high temperatures could preferentially catalyze the hydrogenation of vinyl and nitro groups of NS, respectively. This switching of the product selectivity may be ascribed to actions of surface oxygen-containing functional groups and surface hetero P species. The quantity and nature of these surface species were examined in detail by a few different methods. For the low-temperature reduced catalyst, surface acidic groups present close to Pt nanoparticles (∼2 nm) would interact with the nitro group of a NS molecule and make its vinyl group more likely to interact with the surface active metal species of Pt nanoparticles; this facilitates the hydrogenation of the latter and produces ENB selectively. For the high-temperature reduced catalyst, however, P species would interact with Pt and form Pt-PO x complex, on which a NS molecule is likely to be adsorbed with its nitro group, facilitating the selective production of AS via its hydrogenation. It is demonstrated that surface functional groups and surface hetero atoms (like P), in addition to main active metal species (like Pt), should have direct actions in the catalysis for such a catalyst that exposes a larger quantity of surface functional groups and/or hetero atoms compared to the number of supported metal nanoparticles .
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高影响因子
NATURAL PRODUCT RESEARCH
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2018
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IF 1.928
Xu Pang,Li-Ming Wang,You-Cai Zhang,Li-Ping Kang,He-Shui Yu,Guan-Wei Fan,Li-Feng Han
A continuous phytochemical study on the seeds of Senna obtusifolia (Syn.: Cassia obtusifolia) led to the isolation of a new anthraquinone analogue, obtusifolin-2-O-β-D-(6’-O-α,β-unsaturated butyryl)-glucopyranoside (1) and a new eurotinone analogue, epi-9-dehydroxyeurotinone-β-D-glucopyranoside (2). Their structures were established mainly by NMR and MS experiments as well as the necessary chemical evidences. Their inhibitory effects on two organic anion transporters (OAT1 and OAT3) were investigated and the results showed that 1 exhibited a strongly specific inhibitory effect on OAT1 at 100 μM.
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2019
·
IF 6.393
Xin Xiong,Yao Zhang,YinFang Wang,HaiFeng Sha,Nengqin Jia
By virtue of the metal organic framework UiO-66-NH 2, an ingenious electrochemiluminescence immunosensor was successfully constructed for subtle exploration of the breast cancer biomarker CA 15-3. In this protocol, Ru(bpy) 3 Cl 2 ·6H 2 O (Ru(bpy) 3 2+ ), as a conventional luminescent reagent, provides a stable and strong luminescent signal. The UiO-66-NH 2 serves as a carrier to provide a large specific surface area for enhancing the electrochemical luminescence signal response of Ru(bpy) 3 2+ . UiO-66-NH 2 , Ru(bpy) 3 2+ are fixed together with Nafion membrane, and CA 15-3 antibody is covalently conjugated onto the membrane through the amide reaction. Ru(bpy) 3 2+ @UiO-66-NH 2 is used as the detection system. The experimental results reveal that the ECL signal decreased obviously after the CA 15-3 antigen molecule is captured on the immunosensor, with the capture of manifesting the principle of electrochemical luminescence quenching detection. Under optimal conditions, the sensor is sensitive and selective for detecting CA 15-3 with the detection range from 5 × 10 −4 to 5 × 10 2 U mL -1 and the low LOD (1.7705 × 10 -5 U mL -1 ). Furthermore, multiple experiments elucidate that the as-prepared sensor could be used for susceptibly detect CA 15-3 in actual samples, which has underlying application prospects in biological analysis.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2018
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IF 2.196
Yitong Dai,Wenqi Zhao,Haiyun Sun,Yongsheng Guo,Wenjun Fang
Densities (ρ) and viscosities (η) of ternary system n-dodecane + bicyclohexyl + n-butanol and three corresponding binary systems, n-dodecane + bicyclohexyl, n-dodecane + n-butanol, and bicyclohexyl + n-butanol, were measured at temperature range from 293.15 to 333.15 K in detail. Densities were obtained using a vibrating-tube densimeter. Viscosities were determined using an automatic microviscometer based on the rolling ball principle. The excess molar volumes (VmE) and the viscosity deviations (Δη) of each mixture were calculated with the measured data. The VmE and Δη values of three binary systems were fitted to the Redlich–Kister equation, and those of the ternary system were fitted to Nagata–Tamura, Singh, Clibuka, and Redlich–Kister semiempirical equations. The VmE values are negative for the binary system of n-dodecane + bicyclohexyl with the minimum at about x = 0.5, while those of binary systems n-dodecane + n-butanol and bicyclohexyl + n-butanol are positive over the entire concentration range. For the ternary system, the VmE values are subtotal positive and the Δη are negative over the entire concentration range. The nonideal behaviors of the mixtures are explained by physical interactions and structural effects between mixture components.
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高影响因子
APPLIED SURFACE SCIENCE
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2013
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IF 2.112
Yongbing Yuan,Hongling Chen
The chemical modification of calcined kaolinite particle surface via stepwise method using 3-glycidoxypropyltrimethoxysilane (GPS) and dodecylamine was investigated. Silylation of kaolinite particles was controlled by varying the amount of GPS under almost anhydrous condition. FT-IR and thermal analysis indicated that silylation monolayer coverage on kaolinite particle surface increased with the increasing of the amount of additive GPS, reaching a maximum value of 8.81 μmol/m 2 when the mass ratio of kaolinite to GPS was up to 1:1. Further modification of the silylated kaolinite particle surfaces was accomplished using the modifier synthesized by the ring-open reaction of GPS and dodecylamine to form multilayer branches at the presence of H 2 O (pH = 12). The final modified kaolinite particle surfaces contained both hydrophobic long alkyl chains and hydrophilic groups, which were advantageous to homogeneous dispersion in low polar as well as polar solvents, respectively. Digital photographs and TEM images revealed that the final modified kaolinite particles were homogeneously dispersed in acetone, dioxane, ethanol, and THF, even better than raw kaolinite dispersed in ethanol. Meanwhile, the dispersion properties in low polar solvents such as xylene, cyclohexane and petroleum ether were also acceptable, and the aggregate particle size was near to primary particle size of raw kaolinite, or just a bit larger, increasing from 1.25 to 1.75–2.00 μm.
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高影响因子
JOURNAL OF HETEROCYCLIC CHEMISTRY
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2014
·Vol. 51
·期 4
·1094-1099
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IF 0.873
Guangfan Han,Jiawei Du,Lizhuang Chen,Lijun Zhao
A series of 2-amino-7-methoxy-4-aryl-4 H -chromene-3-carbonitrile compounds 2 were obtained by condensation of 3-methoxyphenol with β-dicyanostyrenes 1 in absolute ethanol containing piperidine. The intermediate enamines 3 were prepared by compounds 2 with 5-substituted-1,3-cyclohexanedione using p -toluenesuflonic acid (TsOH) as catalyst. The title compounds 11-amino-3-methoxy-8-substituted-12-aryl-8,9-dihydro-7 H -chromeno[2,3- b ]quinolin-10(12 H )-one 4 were synthesized by cyclization of the intermediate enamines 3 in THF with K 2 CO 3 /Cu 2 Cl 2 as catalyst. The structures of all compounds were characterized by elemental analysis, IR, MS, and 1 H NMR spectra. The crystal structure of compound 4i was determined by single-crystal X-ray diffraction analysis.
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ELECTROCHIMICA ACTA
·
2015
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IF 4.504
Jinli Mao,Lianyi Shao,Peng Li,Xiaoting Lin,Miao Shui,Nengbing Long,Jie Shu
Three Li 3-x Na x V 2 (PO 4 ) 3 (x=0.5, 1.5 and 2.0) samples are synthesized by a traditional solid-state reaction method in this work. Their phase composition, surface morphology and electrochemical property are described and compared by using various physical/chemical methods. Phase analysis results reveal that Li 2.5 Na 0.5 V 2 (PO 4 ) 3 consists of monoclinic Li 3 V 2 (PO 4 ) 3 , rhombohedral Li 3 V 2 (PO 4 ) 3 and rhombohedral Na 3 V 2 (PO 4 ) 3. While, both Li 1.5 Na 1.5 V 2 (PO 4 ) 3 and LiNa 2 V 2 (PO 4 ) 3 are the two-phase mixture consisted of rhombohedral Li 3 V 2 (PO 4 ) 3 and rhombohedral Na 3 V 2 (PO 4 ) 3 . Electrochemical testing results reveal that LiNa 2 V 2 (PO 4 ) 3 and Li 1.5 Na 1.5 V 2 (PO 4 ) 3 can deliver the initial discharge capacities of 101.4 mAh g −1 and 108.6 mAh g −1 with a long potential plateau at 3.69 V, respectively. In contrast, Li 2.5 Na 0.5 V 2 (PO 4 ) 3 presents an initial discharge capacity of 111.7 mAh g −1 with four potential plateaus. High lithium ion diffusion coefficient in Li 2.5 Na 0.5 V 2 (PO 4 ) 3 indicates that the existence of monoclinic Li 3 V 2 (PO 4 ) 3 phase can improve the ionic conductivity and then be responsible for good electrochemical performance. Besides, in-situ X-ray diffraction observation of LiNa 2 V 2 (PO 4 ) 3 demonstrates that the phase transition is not fully reversible but quasi-reversible during the lithiation-delithiation process. The partial irreversibility of structural evolution for LiNa 2 V 2 (PO 4 ) 3 induces the capacity loss upon repeated cycles.
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高影响因子
ANALYTICAL SCIENCES
·
2014
·Vol. 30
·期 4
·489-494
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IF 1.403
Xiu-Fang YAN,Hai-Long WU,Xiang-Dong QING,Yan-Mei SUN,Ru-Qin YU
In this work, a simple and practicable method that combines excitation-emission matrix (EEMs) fluorescence with a second-order calibration method based on parallel factor analysis-alternative least-squares (PARAFAC-ALS) algorithm was developed for the direct interference-free determination of indole-3-acetic acid (IAA) in two real systems, coconut water (CW) and coconut milk (CM). Although the excitation and emission profiles of IAA heavily overlapped with that of unknown interferents in the complex real systems, the actual contents and satisfactory recoveries were still obtained successfully. The contents of IAA in CW and CM were 10.8 ± 0.3 and 4.9 ± 0.2 μg mL−1, respectively, which were consistent with those reported by LC-MS/MS assays in the reference material. The average spike recoveries of IAA in the validation set based on CW and CM were 102.1 ± 3.2 and 98.0 ± 1.9%, respectively. In addition, routine experiments were performed for establishing the validity of the assay to internationally accepted criteria.
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2013
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IF 2.206
Hong Xu,Fangfang Tong,Jian Yu,Lixiong Wen,Jun Zhang,Jiasong He
Poly(methyl methacrylate) (PMMA) and sodium montmorillonite (Na-MMT) were melt-blended with 1-dodecyl-3-methylimidazolium hexafluorophosphate (C12mimPF6) to prepare nanocomposites containing well-dispersed MMT layers in nanoscale and freely existed excess C12mimPF6. A synergistic effect of MMT and C12mimPF6 on the foaming behavior of nanocomposites was revealed in this study. At the mild conditions of 17 MPa and 35 °C, neat PMMA and PMMA/C12mimPF6 and PMMA/Na-MMT samples were not foamed, while cells were induced in nanocomposites containing a certain amount of free C12mimPF6. At 25 MPa/90 °C, foamed nanocomposites exhibited higher nucleation efficiency and cell density, and smaller cell sizes with narrower size distribution than that of neat PMMA and those binary samples. The results indicated that the MMT nanoparticles produced heterogeneous nucleation, and increased the modulus of polymer matrix to depress cell coalescence. The presence of free C12mimPF6 decreased the energy barrier for cell nucleation and facilitated the dispersion of MMT nanoparticles via in situ organic modification.
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高影响因子
危险品化学品经营许可证（带存储）