Journal of Analytical Methods in Chemistry
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2014
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IF 0.948
Hongzhi Hu,Ying Liang,Shuo Li,Qing Guo,Chancui Wu
In the existence of appropriate amount of disodium ethylenediaminetetraacetate (EDTA), precipitation would not occur in seawater and other natural waters even if the sample solution was adjusted to strong basicity, and the NH3-OPA-sulfite reaction at the optimal pH range could be used to determine ammonium in natural waters. Based on this, a modified o-phthalaldehyde fluorometric analytical method has been established to determine ultratrace ammonium in natural waters. Experimental parameters, including reagent concentration, pH, reaction time, and effect of EDTA, were optimized throughout the experiments based on univariate experimental design. The results showed that the optimal pH range was between 10.80 and 11.70. EDTA did not obviously affect the fluorometric intensity. The linearity range of the proposed method was 0.032–0.500 µmol/L, 0.250–3.00 µmol/L, and 1.00–20.0 µmol/L at the excitation/emission slit of 3 nm/5 nm, 3 nm/3 nm, and 1.5 nm/1.5 nm, respectively. The method detection limit was 0.0099 µmol/L. Compared to the classical OPA method, the proposed method had the advantage of being more sensitive and could quantify ultratrace ammonium without enrichment.
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JOURNAL OF ETHNOPHARMACOLOGY
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2015
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IF 2.998
Hui-Hui Xiao,Quan-Gui Gao,Ming-Xian Ho,Yan Zhang,Ka-Chun Wong,Yi Dai,Xin-Sheng Yao,Man-Sau Wong
Ethnopharmacological relevance Sambucus williamsii Hance (SWH), which belongs to the Caprifoliaceae family distributed in various regions of China, Korea and Japan, has been used as a folk medicine for treatment of bone and joint diseases in China for thousands of years. In previous studies, SWH was shown to possess anti-osteoporosis, healing fracture, anti-inflammatory and analgesic activities. Our previous studies showed that SWH extract effectively suppressed ovariectomy-induced increase in bone turnover and improved bone mineral density and bone biomechanical strength in rats as well as in mice. An 8- O -4′ norlignan, (7 R ,8 S )-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol (PPD) was previously isolated and identified as the bioactive ingredient in SWH. The present study aimed to characterize the bone protective effects as well as its mechanism of actions in osteoblasts. Materials and methods Bone protective actions of PPD on different cells were determined by proliferation assay, alkaline phosphatase (ALP) activity assay, calcium deposition as well as real-time reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, estrogen receptor (ER) antagonist ICI182,780 and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 blocking assays, competitive ER radioligand binding assay, ERE-dependent luciferase reporter assay and immunoblotting were used to determine if PPD activated ER and if the effects of PPD on osteoblastic functions were ER dependent. Results PPD exerted anabolic effects in osteoblasts and its effects were abolished by co-incubation with ICI182,780 or U0126. PPD induced mRNA expressions of Runx2, ALP, osteocalcin, and increased the ratio of osteoprotegerin/receptor activator of nuclear factor κB (OPG/RANKL). PPD failed to bind to either ERα or ERβ and did not activate ERE-luciferase activity via ER. PPD induced the phosphorylation of extracellular regulated kinases (ERK) and its effect was completely abolished by U0126. It also induced the phosphorylation of ERα at serine 118. Conclusion These data show that PPD is a bioactive compound in SWH that exerts oestrogen-like actions in osteoblast-like cells via ligand-independent, estrogen response element (ERE)-independent and mitogen-activated protein (MAP) Kinase-mediated rapid nongenomic ER signaling pathway.
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2015
·Vol. 308
·期 1
·287-295
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IF 1.034
Jing P. F.,Liu H. J.,Zhang Q.,Hu S. Y.,Hu C.,Peng L.,Lei L. L.
The adsorption of thorium(IV) [Th(IV)] was studied using a novel 6-o-monotosyl-deoxy-β-cyclodextrin inclusion complex of dibenzoyl (inclusion complex), which was acquired by the reaction of dibenzoyl and 6-OTs-β-CD with the mole ratio of 1:2. The adsorption of Th(IV) onto inclusion complex were investigated as a function of pH value, contact time, temperature, interfering ions and Th(IV) concentration using batch adsorption technique. The maximum adsorption of Th(IV) and the equilibrium adsorption capacity were found to be 89 ± 1 % and 17.83 mg g −1 respectively at pH 3.0, equilibrium time 20 min and initial Th(IV) concentration 20 mg L −1 . Adsorption kinetics, adsorption isotherm and thermodynamics were carried out.
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JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2017
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IF 1.591
Tengfei Bian,Xiujuan Zhang,Gaohong He,Zhijun Duan,Chunxu Dong,Xiangcun Li,Nana Guo
Hepatic encephalopathy (HE) is a neuropsychiatric disorder caused by chronic and acute liver diseases. It is believed that ammonia played an important role on the pathogenesis of the disease. Herein, acid-loaded water-in-oil-in-water (W1/O/W2) multiple emulsions with over 95% encapsulation efficiency were prepared and used to absorb colonic ammonia. The study of citric acid release from W1 to W2 in bulk deionized water indicated that only 17% acid released in 8 hours, which proved the stability of the multiple emulsions and hence prevented the intestine from being irritated by acid burst release. In vitro, the W1/O/W2 emulsion could remove around 90% ammonia in 1.5 hours from either the 3 mmol/L ammonia solution or the artificial colonic fluid with 1 and 0.5 mmol/L ammonia without acidifying the artificial colonic fluid. In vivo, compared with lactulose, W1/O/W2 emulsions could efficiently reduce the blood ammonia to the similar level in the rat models with HE without increasing the water content in feces. All these results indicated a potential application of W1/O/W2 multiple emulsions for the treatment of HE.
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JOURNAL OF CHROMATOGRAPHY A
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2016
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IF 3.926
Qiqin Wang,Peijie Zhu,Meng Ruan,Huihui Wu,Kun Peng,Hai Han,Govert W. Somsen,Jacques Crommen,Zhengjin Jiang
An O -9-( tert -butylcarbamoyl) quinidine (t-BuCQD) functionalized polymeric monolithic capillary column was prepared by the in situ copolymerization method. The physicochemical properties of the optimized monolithic column were characterized by scanning electron microscopy and micro-LC. Satisfactory column permeability, efficiency, stability and reproducibility were obtained for this monolithic column. The chiral recognition ability of the resulting monolith was also evaluated using 47 N -derivatized amino acids, eight N -derivatized dipeptides, and two herbicides. Under the selected conditions, the enantiomers of all chiral analytes were baseline separated with exceptionally high selectivity and resolution using micro-LC. It is worth noting that this chiral stationary phase (CSP) containing quinidine with a tert -butyl carbamate residue as chiral selector exhibits much higher enantioselectivity and diastereoselectivity than the previously developed O -9-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD) based CSP for N -derivatized amino acids and dipeptides. These results indicate that this novel quinidine-based polymeric monolith can be used as an effective tool for the enantioseparation of chiral acidic compounds.
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CARBOHYDRATE POLYMERS
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2017
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IF 4.811
Xueqian Wang,Mengliu Zhang,Dawei Zhang,Shumei Wang,Chunyan Yan
Osteoporosis is characterized by a reduction in bone mass and bone mineral density, which weakens the bone. Due to the side effects associated with drugs that are currently used to treat this disease, an increasing number of studies have focused on the research of effective ingredients derived from natural products. In particular, polysaccharides extracted from Chinese herbal medicines have received increasing attention. In this study, we isolated a homogeneous polysaccharide (COP90-1) from the dried rhizomes of Curculigo orchioides , a famous traditional Chinese medicine that is widely used in China, and determined its structure using the combined methods of chemical and spectral analyses. In addition, its effects on the proliferation and differentiation of primary mouse osteoblasts were assessed. The results showed that COP90-1 can effectively promote the proliferation and differentiation of primary osteoblasts in vitro . Additional studies are warranted to study the effects of this compound in vivo .
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2016
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IF 2.857
Yu-Chun Wang,Wen-Jun Qian,Na-Na Li,Xin-Yuan Hao,Lu Wang,Bin Xiao,Xin-Chao Wang,Ya-Jun Yang
Tea plant (Camellia sinensis) is one of the most economically valuable crops in the world. Anthracnose can affect the growth of leaves and cause serious yield losses of tea. Tea plants are rich in secondary metabolites; however, their roles in resistance to anthracnose are unclear. Herein we compared the contents of total phenolics, catechins, and caffeine in two cultivars with different resistances to anthracnose during Colletotrichum fructicola infection. (−)-Epigallocatechin-3-gallate (EGCG), (+)-catechin (C), caffeine, and critical regulatory genes were induced in C. fructicola-resistant tissues. In vitro antifungal tests showed that caffeine more strongly inhibited mycelial growth than tea polyphenols and catechins. Both electron microscopy and bioactivity analysis results showed that caffeine can affect mycelial cell walls and plasma membranes. Through promoter sequences analysis, a number of stress response-related cis-acting elements were identified in S-adenosylmethionine synthetase and tea caffeine synthase. These results demonstrated that (−)-EGCG, (+)-C, and caffeine may be involved in the resistance of tea plants to anthracnose.
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RSC Advances
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2017
·Vol. 7
·期 32
·19815-19827
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IF 3.108
Liya Zeng,Xin Xin,Yalin Zhang
Nanoemulsions have attracted much attention due to their wide application in commercial industries such as pharmaceutics, food, beverages and skin care. Cremophor EL has been extensively used for emulsification, protection and solubilization of various lipophilic bioactive agents. However, their anaphylactoid hypersensitivity reactions are still challenging. Therefore, the aim of this study was to develop and characterize a promising, low-level Cremophor EL-stabilized o/w nanoemulsion using the spontaneous emulsification method for oral administration. From comparing the physicochemical properties (particle size and size distribution) of their emulsions, Cremophor has better emulsifying capacity than Tween and the droplet radius of emulsions can be reduced by increasing the surfactant concentration in current systems. The impact of various short-chain alcohols (C–OH < 5) on the formation and stability of nanoemulsions was also investigated to optimize the formulations. And there is a good correlation between nanoemulsion droplet size and the surfactant packing parameter (p). The smallest droplet size with the narrowest size distribution was produced by the system containing ethylene glycol as a cosurfactant. However, preparation of nanoemulsions with ethylene glycol was a time-consuming process since it was difficult to emulsify the water-induced gel-structure. Surfactant-to-oil mass ratio and surfactant-to-cosurfactant levels had to be optimized to produce fine droplets. Moreover, there was a linear relationship between the viscosity/log P value of alcohols and droplet size. Ostwald ripening was the dominant breakdown process of nanoemulsions obtained in the ethyl oleate/Cremophor EL–butanol (3 : 2)/water system. Ostwald ripening rate was increased with increasing surfactant concentration. Dilution (100×) of this system considerably improved their stability against droplet growth. This study demonstrated that alcohol addition might be a useful tool for preparing Cremophor EL-stabilized nanoemulsions for pharmaceutical applications.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2016
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IF 2.822
Changling Yan,Xun Liu,Ruixing Zhang,Yujuan Chen,Gongke Wang
In this work, a novel approach for selective and sensitive detection of ascorbic acid (AA) was proposed combined molecularly imprinted polymers and electrochemical sensor. The molecularly imprinted sensor was prepared by cyclic voltammetry on pencil graphite electrode with pyrrole (Py) and o-phenylenediamine (o-PD) as functional monomers and AA as template molecule. The sensor was evaluated through scanning electron microscope (SEM) and square wave voltammetry (SWV). The factors affecting electrochemical response of sensor were investigated and optimized. Under the optimum conditions, the imprinted sensor exhibited good selectivity and stability. The linear range of the sensor was 1 × 10 − 6 to 1 × 10 − 3 mol/L, meanwhile, the detection limit was 2.63 × 10 − 7 mol/L (S/N = 3). This molecularly imprinted sensor has been successfully used in AA determination in real tablet samples with good recovery.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2017
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IF 3.133
Shu Huang,Min Zhou,Kangli Wang,Shijie Cheng,Guoping Yan,Kai Jiang
Electrochemical synthesis method is an effective, controllable and cost-effective synthesis route for fabricating various kinds of metal compounds. Here, for the first time, we synthesis the Li-Mo-O compounds by electrolysing MoO 3 in molten LiCl-LiBr salt at 600 °C. The as-prepared LiMoO 2 and Li 2 MoO 4 were evaluated as novel anode materials for lithium ion batteries (LIBs), delivering high reversible capacities of 565 and 473 mAh g −1 , respectively. More significantly, the LiMoO 2 @C show extra high initial columbic efficiency of 80% with superior rate capability and long cycling stability over 200 cycles. This facile and green electrochemical synthesis route described in this work can provide new insights for the development of promising host materials for practical LIBs in large-scale energy storage applications.
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FOOD HYDROCOLLOIDS
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2024
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IF 11
Kaixin Li,Xin Yuan,Jiajia Zhao,Jinbo Ren,Lingjun Ma,Xiaojun Liao,Xiaosong Hu,Fang Chen,Junfu Ji
The unique structural of anthocyanins makes them vulnerable to degradation within food processing environments. Proteins commonly coexist with polyphenols in natural food matrices on a non-covalent and covalent basis, serving to stabilize protection for polyphenols. Here, three natural pea-extracted proteins, including albumin, vicilin, and legumin were bound to cyanidin-3-O-glucoside (C3G), and binding modes, conjugate structures and functions were characterized. Isothermal titration calorimetry showed a strongly exothermic interaction between C3G and proteins. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fourier transform infrared spectroscopy revealed that the C3G-quinone (C3GQ) formed by C3G oxidation established covalent cross-links with C–S and C–N in the amino acid residues of proteins, and could form more large molecular weight aggregates at an addition amount of 1 mM. The free sulfhydryl and amino contents of the three protein conjugates decreased with the addition of C3GQ. Due to the presence of 4–5 times more sulfhydryl groups in albumin as compared to globulin, albumin showed a 20% higher binding capacity for C3GQ than globulin. This consequently led to the highest antioxidant activity in the C3GQ-albumin conjugate. In contrast to native pea proteins, the introduction of covalent modifications induces changes in the secondary structure of the pea proteins. Specifically, the structure of albumin tends to exhibit increased orderliness, while the molecular flexibility of globular proteins was augmented. Thus, the conjugates have enhanced thermal stability. Our results affirmed that the stability of C3G can be more effectively improved through designing it to covalently interact with proteins relative to non-covalent interactions. This study aimed at offering novel theoretical underpinnings for the functional utilization of C3G and pea proteins in the food industry.
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ENERGY & FUELS
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2024
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IF 5.2
Changlong Yin,Yihang Han,Lingtong Meng,Yongqiang Guo,Yu Yan,Dong Liu,Huiji Zhao,Yongming Chai,Chenguang Liu
Biolipids and oil hydrogenation are prominent alternatives to petroleum-based fuels. Currently, the catalysts used are limited to deoxidation activity, resulting in the reaction products with a high content of n-alkanes and waxes, necessitating secondary treatment to increase iso-alkane content. Herein, an unsupported Ni–Nb–O catalyst with trifunctional capabilities (i.e., hydrodeoxygenation, hydrocracking, and isomerization) was developed for the efficient conversion of methyl stearate and jatropha oil into small molecular alkanes. The metal ratio significantly affects the catalytic performance, in which Ni/Nb = 2:0.6 exhibited the highest isomerization activity. Moreover, 84% of the deoxidized products are C8–C17 hydrocarbons, with 53.4% being isomeric hydrocarbons. The catalyst also demonstrated excellent stability, maintaining 54% selectivity for C8–C17 iso-alkanes in jatropha oil feedstock during 240 h of operation.
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