枸杞多糖体清除自由基活性研究

采用超氧阴离子自由基体系、羟基自由基体系、烷基自由基引发的亚油酸氧化体系、二苯代苦味肼基自由基DPPH体系,对枸杞多糖的抗氧化活性进行了研究,并同Vc进行了比较.结果表明：枸杞多糖对这几种自由基均有不同程度的清除作用,其对超氧阴离子清除作用不明显;清除羟基自由基能力与Vc相当;在较小浓度时,清除烷基自由基和DPPH自由基能力弱于Vc,但在较高浓度与Vc接近.     

超级黑糯玉米芯色素的抗肿瘤和体外抗氧化作用

为研究超级黑糯玉米芯色素(super black glutinous corncob pigment,SBCP)对肿瘤细胞的增殖抑制效应和体外抗氧化活性.采用MTT法检测了SBCP对人肝癌细胞系BEL-7402以及胃癌细胞系SGC-7901增殖的影响;在体外化学模拟的条件下,通过建立DPPH自由基、羟基自由基、超氧阴离子自由基、还原力试验,采用比色法测定对比了SBCP和抗坏血酸(Vc)对DPPH自由基、羟基自由基和超氧阴离子的清除作用以及还原能力.结果表明SBCP对BEL-7402细胞和SGC--7901细胞增殖有明显的抑制作用,且随药物浓度的增大而增强;SBCP对两种肿瘤细胞的半数抑制浓度(IC50)分别为4.13 mg/mL和3.83 mg/mL.SBCP还具有较好的抗氧化作用,对羟基自由基和超氧阴离子的清除作用分别是Vc的1.4倍和1.23倍,还原能力是Vc的1.77倍,但对DPPH自由基的清除作用略低于Vc.SBCP在癌症预防和治疗以及食品保健方面具有潜在的应用价值;SBCP具有很好的体外抗氧化活性.     

紫甘薯膳食纤维的提取及对自由基的清除作用

以紫甘薯为材料,设计4因素3水平的正交实验,酶法提取膳食纤维。结果表明紫甘薯粉中膳食纤维提取的最佳工艺参数为0.7%的混合酶(其中α-淀粉酶∶糖化酶为6∶1),酶解温度70℃,处理时间80min,0.6%蛋白酶。以体外实验研究不同质量浓度(20~140mg/mL)的膳食纤维鲜样对1,1-二苯基-2-苦味酰基自由基(DPPH)、超氧阴离子自由基(O-2·)、羟自由基(·OH)的清除效果。结果表明紫薯膳食纤维对DPPH O-2·、·OH都有明显的清除效果,在20~140mg/mL的膳食纤维的浓度范围内,其清除自由基的效果随着膳食纤维的浓度增大而增强,但当浓度增加到一定程度后,对DPPH、超氧阴离子自由基的清除能力趋于平缓,对·OH的清除效果呈直线上升;其清除能力顺序为:DPPH自由基超氧阴离子自由基羟自由基。     

黑豆水提物抗氧化性能

对黑豆水提物抗氧化性能进行了研究。采用邻苯三酚自氧化法、水杨酸法、DPPH.法,以同浓度的维生素C作为阳性对照,测定了黑豆水提物对超氧阴离子、羟基自由基、DPPH.自由基的清除能力。结果表明：黑豆水提物对超氧阴离子自由基、羟基自由基、DPPH·自由基均具有一定的清除能力,其IC50值分别为121.6μg/mL,28.4μg/mL,32.8μg/mL,说明黑豆水提物可以作为天然的抗氧化剂应用于食品和化妆品行业。     

桑叶总黄酮清除自由基作用研究

利用紫外光谱法研究了桑叶总黄酮对1,1-二苯基-2-苦肼基自由基（DPPH.）、羟基自由基和超氧阴离子自由基的清除作用.结果表明,桑叶总黄酮能有效清除DPPH自由基、羟基自由基和超氧阴离子自由基,清除率分别达到86.10%,86.02%,43.64%.     

大孔吸附树脂提取粗壮女贞苦丁茶总黄酮及抗氧化活性

目的:研究大孔吸附树脂分离纯化苦丁茶总黄酮的最佳工艺及黄酮化合物的抗氧化活性.方法:采用大孔吸附树脂法获得总黄酮.利用紫外分光光度法测定苦丁茶总黄酮不同浓度下在体外对DPPH自由基、超氧阴离子自由基、羟基自由基和ABTS自由基的清除能力.结果:大孔吸附树脂提取最佳工艺为上样流速为3 mL/min,上样浓度为1.2 mg/mL,其黄酮类化合物在体外抗氧化的能力包括ABTS自由基、DPPH自由基、超氧阴离子自由基和羟基自由基,在不同浓度下的最大清除能力分别为88.65%、87.94%、89.11%和73.21%.结论:总黄酮对4种自由基有良好的清除效果.     

脱脂沙苑子乙醇提取物的体外抗氧化活性研究

通过测定脱脂沙苑子乙醇提取物(ESA)对1,1-二苯基-2-苦苯肼自由基(DPPH·)、超氧阴离子自由基(O-·2)和羟基自由基(·OH)的清除能力、对Fe2 诱导的脂质过氧化反应的抑制作用、还原力和总抗氧化力,评价ESA的体外抗氧化活性,并与公认的抗氧化剂维生素C作了对照.结果表明,ESA有一定的DPPH·清除能力(IC50=419.1μg/mL)、较强的超氧阴离子清除能力(IC50=117.9μg/mL)和羟基自由基清除能力(IC50=224.4μg/mL),能有效的抑制脂质过氧化(IC50=1.70 mg/mL),有良好的总抗氧化力,说明沙苑子具有明显的抗氧化活性.     

三种海藻体外抗氧化活性的研究

在体外化学模拟环境的条件下,采用比色法测定了羊栖菜,条浒苔和坛紫菜醇提物对DPPH自由基,羟基自由基和超氧阴离子的清除能力以及抗脂质过氧化能力。羊栖菜醇提物显示出较强的DPPH自由基清除能力,羟基自由基清除能力与抗脂质过氧化能力,坛紫菜醇提物显示出较强的超氧阴离子自由基清除能力与抗脂质过氧化能力。     

多羟基二苯甲酮的抗氧化性能研究

采用Friedel-Crafts反应合成18个多羟基二苯甲酮系列化合物,并从清除羟基自由基和超氧阴离子自由基能力两个方面研究了该系列化合物的体外抗氧化活性。结果表明,该系列化合物对上述两种自由基有较好的清除效果,其中羟基自由基的清除能力比Vc强,而超氧阴离子自由基的清除能力比Vc稍弱。本文的研究填补了多羟基二苯甲酮系列化合物在抗氧化性能研究的空白,为该类抗氧化剂的设计合成提供了有益参考。     

洋葱不同溶剂提取物体外抗氧化活性评价

通过测定还原力、螯合能力及其对羟基自由基、DPPH自由基、超氧阴离子自由基的清除能力等实验研究了洋葱5种不同溶剂提取物的体外抗氧化活性。实验结果表明：洋葱水提物的还原力最强,对DPPH自由基、超氧阴离子自由基和羟基自由基清除能力也最强;丙酮提取物对Fe2＋的螯合能力最强。综合评价,洋葱水提取物的抗氧化活性最强。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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