EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2014
·Vol. 238
·期 5
·889-894
·
IF 1.387
Zhu Jinghui,Li Chunyan,Liu Shaopu,Liu Zhongfang,Yang Jidong,Tian Jing,Hu Xiaoli
A non-diazotization-coupling reaction-based colorimetric method was developed and validated for the determination of nitrite in tap water and milk samples. Under acidic condition, nitrite could selectively react with pyrrole, resulting in the emerging of a new absorption peak at 509 nm and a distinct color change from clear to red, with which the concentration of nitrite can be determined indirectly. Excellent linear range was achieved from 0.72 to 40.0 μmol L −1 with a detection limit of 0.22 μmol L −1 . The detection limit was lower than or comparable to most of the recently published methods. The experimental conditions were optimized, and effects of coexisting substances were evaluated, and the results showed excellent priority since a certain amount of other anions, including SO 3
− , SeO 3
− and other acid radicals, would not interfere with the measurement. We highlighted the simplicity and efficiency of this method as no diazotization-coupling procedure and toxic aniline were involved. Determination of nitrite in tap water and milk samples was performed.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 5
·540-550
·
IF 1.42
Guo Hua,Yang Cheng-ling,Wang Wei,Wu Yu-kun,Lai Quan-yong,Yuan Zhi
A series of drug delivery systems based on a sodium alginate derivative were prepared by mixing glycyrrhetinic acid (GA) and doxorubicin (DOX) conjugates at different ratios. GA (a liver-targeting ligand) and DOX (an antitumor drug) were both conjugated to oligomeric glycol monomethyl ether-modified sodium alginate (ALG-mOEG) for prolonged duration of action. These NP-based delivery systems exhibited active cell uptake and cytotoxicity in vitro and liver-targeted distribution and anti-tumor activity in vivo . In addition, nanoparticles with a 1:1 ( W : W ) ratio of GA-ALG-mOEG and DOXALG-mOEG (NPs-3) showed the highest cellular uptake and cytotoxicity in vitro and liver-targeted distribution and antitumor activity in vivo . Specifically, when mixed nanoparticles defined as NPs-3 were injected in mice, liver DOX concentration reached 61.9 μg/g 3 h after injection, and AUC 0-∞ and t
1/2 of DOX in liver reached 4744.9 μg·h/g and 49.5 h, respectively. In addition, mice receiving a single injection of NPs-3 exhibited much slower tumor growth (88.37% reduction in tumor weight) 16 days after injection compared with placebo. These results indicate that effective cancer treatment may be developed using mixed NP delivery systems with appropriate ratio of targeted ligand and drug.
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WATER AIR AND SOIL POLLUTION
·
2013
·Vol. 224
·期 7
·1-10
·
IF 1.748
Liu Fahui,Wang Chuanhua,Liu Xiaoyan,Liang Xia,Wang Qian
This research evaluated the effects of alkyl polyglucoside (APG), an environment-friendly surfactant, on the removal of anthracene (ANT), phenanthrene (PHE), and pyrene (PYR) from the soil cultivated with Scirpus triqueter , an aquatic native pioneer plant in the Yangtze estuarine wetland, China. Soils spiked with about 200 mg kg −1 of ANT, PHE, and PYR were individually irrigated with 0, 10, 20, 30, 40, 50, 100, and 150 mg L −1 of APG. Plant biomass yields, polycyclic aromatic hydrocarbons (PAHs) removal rates, soil microbial, and soil enzyme activities were quantified after 90 days’ cultivation of Scirpus triqueter . Experiments demonstrated that APG has an ability to facilitate PAHs degradation at appropriate concentrations. The highest removal rate of the PAHs was observed in 40 mg L −1 APG treatment, and the removal rates increased 23, 54, and 52 %, respectively, compared to the non-amended control pots. However, the PAHs removal rate decreased to a certain extent when high concentrations of APG were added. The effect on PAHs removal in the soil could be explained by the changed levels of plant biomass, soil microbial populations, and soil enzymatic activity affected by the APG. The results suggested that the use of Scirpus triqueter combined with APG was an effective means for the phytoremediation of the PAH-contaminated soil. At the same time, APG’s optimal concentration should be determined before the application in the PAH-contaminated wetlands.
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CATALYSIS LETTERS
·
2013
·Vol. 143
·期 9
·873-880
·
IF 2.244
Yang Lan,Luo Wei,Cheng Gong-Zhen
Abstract Amorphous nickel catalysts derived from nickel halides (NiF 2 , NiCl 2 , NiBr 2 , NiI 2 ) were in situ synthesized in an aqueous solution of NaBH 4 /NH 3 BH 3 . The halide anions have effects on the formation of Ni(0) catalysts, which can further affect the catalytic activities and activation energies of the catalysts for the hydrolysis of ammonia borane. The PVP stabilized catalysts have higher hydrogen evolution rates and durabilities than bare Ni catalysts for the hydrolysis of ammonia borane. The catalysts derived from NiBr 2 stabilized by PVP present the highest catalytic activity and the lowest activation energy, which has been measured to be 25.58 kJ/mol. This value is lower than most of reported Ni-based catalysts and even noble-metal containing catalysts. The results of mercury poisoning experiment reveal that Ni(0) catalysts derived from NiBr 2 are heterogeneous catalysts in the hydrolysis of ammonia borane. Graphical Abstract
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MICROCHIMICA ACTA
·
2013
·Vol. 180
·期 7
·695-702
·
IF 3.434
Zhang Ting,Ma Chao,Wu Mei,Ye Yong,Chen Huaixia,Huang Jianlin
We report on an organic–inorganic hybrid material that was double imprinted with the insecticide carbaryl and the anti-inflammatory drug naproxen by a single-step method and that can serve for selective microextraction of the two analytes. The materials, in the form of monolithic columns, were characterized by scanning electron microscopy and Fourier transform IR spectra. A simple, rapid and sensitive method was then developed for the simultaneous determination of carbaryl and naproxen in lettuce and river water using these columns for microextraction, HPLC for separation, and a diode array for UV detection. The limits of detection (at S/N = 3) and quantification (at S/N = 10) are in the ranges of 2.5 – 8.8 μg kg −1 and 2.3 – 8.0 μg L −1 for lettuce and Yangtze River water, respectively. The recoveries of this method range from 93.0 to 108 % (in case of analyzing lettuce and river water), and relative standard deviations are <8.9 %.
An organic–inorganic hybrid carbaryl and naproxen imprinted monolithic column was synthesized, characterized and applied. The derivated double-template imprinted polymer showed high selectivity and enrichment ability for templates. It can be used as an alternative technique for extracting carbaryl and naproxen from complex samples.
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Journal of Nanostructure in Chemistry
·
2014
·Vol. 4
·期 3
·1-8
·
IF 0
Li Lihua,Feng Dexiang,Fang Xian,Han Xiaowei,Zhang Yuzhong
In this work, we have developed a novel visual Hg 2+ sensor in aqueous solution using unmodified Au@Ag core–shell nanoparticles at room temperature, based on a redox reaction between Ag-shell and Hg 2+ . The prepared Au@Ag core–shell nanoparticles exhibited good monodispersity. In the presence of Hg 2+ , Hg 2+ was reduced into Hg (0) by Ag-shell, and deposited on the surface of Au-core to form Au–Hg alloys and caused nanoparticles aggregation, leading to the color changes of the solution from yellow to purplish red, and the surface plasmon resonance spectra of Au@Ag core–shell nanoparticles red shift. Under the optimal conditions, the visual sensor could selectively detect Hg 2+ as low as 0.4 µM with the naked eye and 5.0 nM by UV–vis spectra analysis methods. The designed sensor had several advantages: (1) the nanoparticles surface need not be functionalized. (2) The color change of the solution was in 2 s and could easily be observed with naked eyes. The visual sensor had been applied to detection of Hg 2+ in tap and lake water, which obtained satisfied result.
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CHROMATOGRAPHIA
·
2014
·Vol. 77
·期 19
·1379-1386
·
IF 1.37
Liu Huijun,Li Caixia,Wang Hong,Huang Zhongping,Zhang Peipei,Pan Zaifa,Wang Lili
Headspace solid-phase microextraction and gas chromatography/mass spectrometry (HS-SPME–GC/MS) method combined with XCMS Online was tentatively applied to characterize the dysregulated volatile organic metabolites (VOMs) in benign and malignant pleural effusions. A total of 9 dysregulated feature groups were isolated from metabolic features in 35 pleural effusion samples (20 benign effusions and 15 malignant ones from lung cancer patients). Principle component analysis, partial least squares discriminant analysis (PLS-DA) and orthogonal PLS-DA were built to separate benign from malignant pleural effusion groups and to find dysregulated metabolites in significantly different amounts between the two groups. Four dysregulated VOMs such as 2-ethyl-1-hexanol, cyclohexanone, 1,2,4,5-tetramethylbenzene and naphthalene were selected according to the variable influence on the projection value. The concentration of the four dysregulated VOMs in benign and malignant effusions were further determined by external standard method. The median concentrations of 4 VOMs in malignant effusion samples were from 4.7 to 91,121.9 nM, whereas their median levels were only 1.9–318.3 nM in benign ones. The results show that the proposed SPME–GC/MS-based metabolomic approach combined with XCMS Online data processing is a simple, rapid and available method for the characterization of dysregulated VOMs in malignant and benign pleural effusions.
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Forensic Toxicology
·
2014
·Vol. 32
·期 2
·331-337
·
IF 5.756
Wurita Amin,Hasegawa Koutaro,Minakata Kayoko,Watanabe Kanako,Suzuki Osamu
Traffic police brought five dubious herbal product packages to our laboratory for toxicological analysis. These products usually contain one or multiple kinds of synthetic cannabinoids. In one of the packages, we identified the coexistence of a new type of dubious drug (diphenidine) with the synthetic cannabinoid 5-fluoro-AB-PINACA. Conclusive identification was performed by comparison of the mass spectra of the test herb extracts with those of the reference standards of diphenidine and 5-fluoro-AB-PINACA by both gas chromatography–mass spectrometry (GC–MS) and electrospray ionization–tandem mass spectrometry. Both mass spectra of the test extracts coincided with those of the reference standards for each MS method. Diphenidine and 5-fluoro-AB-PINACA were quantitated in the herbal product by GC–MS using selected ion monitoring and the standard addition method. The content of diphenidine in the herbal product was as high as 289 ± 23.2 mg/g ( n = 5); that of 5-fluoro-AB-PINACA was 55.5 ± 5.8 mg/g ( n = 3). Diphenidine is known as an N -methyl- d -aspartate receptor channel blocker. Although its human toxicity has not been studied, it is likely to have severe psychotropic action in humans. The very high content of diphenidine in the present herbal package should prompt law enforcement agencies to be aware of the potential harmful effects of diphenidine itself and also when consumed in combination with other drugs of abuse.
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JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 49
·期 20
·7133-7142
·
IF 2.305
Bu Xiaohai,Zhou Yuming,Zhang Tao,He Man
Optically active substituted polyacetylene@CdSe quantum dots (SPA@CdSe QDs) nanocomposites were fabricated by grafting helical SPA polymers onto the surface of semiconductor QDs through ester linkage. Optically active SPA polymer derived from chiral amino acids was copolymerized by a rhodium zwitterion catalyst and was evidently proved to adopt a predominately single-handed helical conformation. The SPA@QDs nanocomposites were characterized by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and thermogravimetric analysis. The results indicated that the organic SPA matrix exhibited an enhancement in thermal stability after the hybridization with CdSe QDs, while the blended QDs maintained their original crystalline structure during grafting. The infrared emissivity properties of the SPA@QDs nanocomposites at 8–14 μm were further investigated. The data demonstrated that the SPA@QDs-15 composite film possessed an infrared emissivity value of 0.501, which was much lower than pristine SPA and QDs. This might be attributed to the incorporation of optically active helical SPA and semiconductor QDs in a hybrid phase, which had great effect in enhancing their interfacial interactions.
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EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2014
·Vol. 239
·期 5
·827-835
·
IF 1.387
Wang Panxue,Li Aixia,Dong Mei,Fan Mingtao
The aim of this study was to purify a malolactic enzyme (MLE) from Oenococcus oeni ( O. oeni ) strain and determine its properties in detail. O. oeni SD-2a was cultivated in the ATB broth supplemented with 7 g/L l -malic acid for harvesting the cells. After harvest, the cells were washed and disrupted for purification of MLE. MLE was purified from the supernatant of the disrupted cells through protamine sulfate precipitation, anion exchange chromatography and gel filtration chromatography. The purified MLE was identified using mass spectrometry. The MLE was purified by 43-fold with a yield of 0.42 % and possessed a specific activity of 419.2 U/mg. The purified enzyme with a nominal molecular mass of 59 kDa and a theoretical p I of 4.76 exhibited a maximum enzyme activity at 35 °C and pH 6.0, which retained over 50 % of its initial activity in the presence of 14 % (v/v) ethanol. Mn 2+ was proven to be the most effective divalent cation to promote enzyme activity. Under the conditions of temperature 30 °C and pH 6.0, the K
m and V
max of MLE on l -malic acid were 12.5 × 10 −3 M and 43.86 μmol/(min × mg), respectively. Moreover, the purified enzyme exhibited a higher stability with 0.1 M NaCl in addition and had a half-life of 30 days at 4 °C.
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BioEnergy Research
·
2014
·Vol. 7
·期 4
·1541-1549
·
IF 3.398
Zhang Haidong,Zou Yu,Shen Yu,Gao Xue,Zheng Xuxu,Zhang Xianming,Chen Youpeng,Guo Jinsong
Three mesoporous silica materials with various channel sizes and structures were employed to prepare immobilized lipase catalysts for the transesterification of unrefined wasted cooking oil (UWCO) to biodiesel at room temperature. The channel size of support material was found to be the key point to obtain high initial specific activity and high sustainability of activity of the immobilized lipase catalysts. A SBA-15 material with appropriate channel size (14.0 nm) demonstrates the best capacity of lipase. The immobilized catalyst with the SBA-15 material shows much higher activity and sustainability of activity than the immobilized catalysts with a MCM-41 material (channel size 1.8 nm) and a mesostructured cellular foam (MCF) material (channel size 28.0 nm) as support materials in the transformation of UWCO to biodiesel. After 60 h of reaction at 28 °C, a fatty acid methyl ester (FAME) yield up to 80.1 and 71.8 % of initial specific activity can be achieved using SBA-15-immobilized lipase.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2014
·Vol. 31
·期 7
·1276-1280
·
IF 1.241
Yuan Xiangxi,Ma Xiaolei,Cao Xuejun
A novel method of producing ursodeoxycholic acid was developed through direct electro-reduction of 7-ketolithocholic acid in a divided electrolytic cell. Titanium ruthenium mesh electrode was used as the anode, while high purity lead plate was used as the cathode. The process was optimized with regards to the electrolyte, temperature, concentration of methanol, current density and concentration of anolyte. When potassium bromide was used as the electrolyte, the saturated solution of 7-ketolithocholic acid in 85–93% (v/v) methanol, current density 9.52–28.6 A/m 2 and concentration of anolyte at 4–6% (w/w), the maximum percentage yield of ursodeoxycholic acid could be 47%. The method will provide a potential approach for large-scale production of ursodeoxycholic acid.
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