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Evaluating bioactivity and bioaccessibility properties of the propolis extract prepared with L-lactic acid: An alternative solvent to ethanol for propolis extraction

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FOOD BIOSCIENCE 2023年第3期53卷 2351-2358页

作者： Atayoglu, Ali Timucin Atik, Didem Sozeri Boluk, Esra Gurbuz, Basak Ceylan, Fatma Duygu Capanoglu, Esra Atayolu, Rumeysa Paradkar, Anant Fearnley, James Palabiyik, Ibrahim Istanbul Medipol univ Tradit & Complementary Med Dept Istanbul Turkiye Tekirdag Namik Kemal univ Food Engn Dept Tekirdag Turkiye Istanbul Tech univ Food Engn Dept Istanbul Turkiye Istanbul Medipol univ Nutr & Dietet Dept Istanbul Turkiye univ bradford Ctr Pharmaceut Engn Sci Sch Pharm Bradford W Yorkshire England Apiceut Res Ctr Whitby N Yorkshire England

Ethanol readily solubilizes the active components of propolis. Due to certain disadvantages of ethanolic extracts, developing new non-ethanolic extraction methods is highly desirable. This study aimed to determine the content of phenolic compounds and antioxidant activity of propolis by using lactic acid extraction compared to ethanol. Various concentrations of ethanol and lactic acid were utilized to produce extracts, and an in vitro digestion procedure was applied to the extracts to compare the bioaccessibility of phenolic compounds by using LC-MS/MS in extracts and HPLC-DAD in digested samples. The compounds detected in the lactic acid-based propolis so-lution had similar values to those in the ethanol solution at a propolis concentration of 10%. The propolis-lactic acid solution had a significantly higher antioxidant activity against DPPH radical than the one prepared with ethanol at the same concentration (p < 0.05). Chrysin and naringenin were found as the most abundant phenolic compounds in the initial samples during in vitro digestion experiments. Pinocembrin was the most bioaccessible component among the dialyzed IN fractions of ethanol and lactic acid-based solutions, whereas some compounds were not detected. The results suggest that lactic acid may be used as an alternative to ethanol for propolis extraction.

关键词： Antioxidant Extraction Lactic acid Propolis Phenolics

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竞争政策与多边贸易体制下的中国贸易政策

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山西大学学报(哲学社会科学版) 2003年第1期26卷 28-32页

作者：吴莉芳,张英中共中央党校研究生院英国bradford大学经济系北京100091 BD71DP U.K.

文章以竞争政策为主线 ,论证了竞争政策与入世后中国贸易政策的选择与发展之间的关系。提出这样几个观点 :(1)以开放促竞争 ,将中国独特的比较优势转化为竞争优势 ;(2 )竞争政策是入世后中国贸易政策选择与发展的出发点 ;(3)竞争政策并... 详细信息

文章以竞争政策为主线 ,论证了竞争政策与入世后中国贸易政策的选择与发展之间的关系。提出这样几个观点 :(1)以开放促竞争 ,将中国独特的比较优势转化为竞争优势 ;(2 )竞争政策是入世后中国贸易政策选择与发展的出发点 ;(3)竞争政策并不排斥贸易保护 ,中国应该选择实施以竞争政策为基石的适度贸易保护政策 ;(4)以竞争政策作为中国贸易政策的出发点有利于消除“发达国家”、“不公平贸易行为”等“灰色”影响。

关键词：竞争政策贸易政策适度贸易保护 WTO

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High-repetition-rate source of nanosecond duration kA-current pulses driven by relativistic laser pulses

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High Power Laser Science and Engineering 2024年第3期12卷 106-115页

作者： Michael Ehret Jakub Cikhardt Philip Wykeham bradford Iuliana-Mariana Vladisavlevici Tomas Burian Diego de Luis Jose Luis Henares Rubén Hernández Martín Jon Imanol Apiñaniz Roberto Lera JoséAntonio Pérez-Hernández João Jorge Santos Giancarlo Gatti Centro de Láseres Pulsados(CLPU) VillamayorSpain Czech Technical university in Prague Faculty of Electrical EngineeringPragueCzech Republic univ.Bordeaux-CNRS-CEA Centre Lasers Intenses et Applications(CELIA)UMR 5107TalenceFrance Department of Radiation and Chemical Physics FZU-Institute of Physics of the Czech Academy of SciencesPragueCzech Republic

We report the first high-repetition-rate generation and simultaneous characterization of nanosecond-scale return currents of kA-magnitude issued by the polarization of a target irradiated with a PW-class high-repetition-rate titanium:sapphire laser system at relativistic *** present experimental results obtained with the VEGA-3 laser at intensities from5×10^(18)to 1.3×10^(20)W cm^(-2).A non-invasive inductive return-current monitor is adopted to measure the derivative of return currents of the order of kA ns-1and analysis methodology is developed to derive return *** compare the current for copper,aluminium and Kapton targets at different laser *** data show the stable production of current peaks and clear prospects for the tailoring of the pulse shape,which is promising for future applications in highenergy-density science,for example,electromagnetic interference stress tests,high-voltage pulse response measurements and charged particle beam *** compare the target discharge of the order of hundreds of nC with theoretical predictions and a good agreement is found.

关键词： current pulses electromagnetic pulse application high-power laser relativistic laser plasma

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Biochemical, chromatographic and spectroscopic analyses of Suwannee River fulvic acid—Evidence for the presence of a DNA-like material

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Chinese Journal Of Geochemistry 2006年第B8期25卷 267-267页

作者： Nawab ALI Graduate Institute of Technology university of Arkansas at Little Rock 2801 S. univ. Ave. Little Rock AR 72204 USA

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Proton deflectometry of a capacitor coil target along two axes

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High Power Laser Science and Engineering 2020年第2期8卷 10-18页

作者： P.bradford M.P.Read M.Ehret L.Antonelli M.Khan N.Booth K.Glize D.Carroll R.J.Clarke R.Heathcote S.Ryazantsev S.Pikuz C.Spindloe J.D.Moody B.B.Pollock V.T.Tikhonchuk C.P.Ridgers J.J.Santos N.C.Woolsey York Plasma Institute Department of PhysicsUniversity of YorkHeslingtonYork YO105DDUK Centre Lasers Intenses et Applications University of Bordeaux-CNRS-CEA33405 TalenceFrance Institut fur Kernphysik Tech.Univ.Darmstadt64289 DarmstadtGermany Central Laser Facility Rutherford Appleton LaboratoryChiltonDidcotSTFCUKRIOxfordshireUK Joint Institute for High Temperatures RASMoscow 125412Russia National Research Nuclear university MEPhI Moscow 115409Russia Lawrence Livermore National Laboratory LivermoreCalifornia 94551USA ELI Beamlines Institute of PhysicsCzech Academy of SciencesZa Radnicic 83525241 DolníBrezanyCzech Republic

A developing application of laser-driven currents is the generation of magnetic fields of picosecond-nanosecond duration with magnitudes exceeding B=10 ***-loop and helical coil targets can direct laser-driven discharge currents along wires to generate spatially uniform,quasi-static magnetic fields on the millimetre ***,we present proton deflectometry across two axes of a single-loop coil ranging from 1 to 2 mm in *** with proton tracking simulations shows that measured magnetic fields are the result of kiloampere currents in the coil and electric charges distributed around the coil *** this dual-axis platform for proton deflectometry,robust measurements can be made of the evolution of magnetic fields in a capacitor coil target.

关键词： strong magnetic field laser-driven coil targets laser-plasma interaction proton deflectometry laboratory astrophysics

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