金果榄总皂苷抗氧化活性研究

研究了金果榄总皂苷对羟基自由基、亚硝酸盐清除能力,对亚硝胺的阻断能力及对三价铁离子的还原力,并依据该5种指标讨论了金果榄总皂苷的抗氧化活性及总皂苷浓度与其抗氧化活性的关系。研究结果表明,随着总皂苷浓度的增大,总皂苷对羟自由基、亚硝酸盐、超氧阴离子的清除能力以及阻断亚硝胺能力和总黄酮还原力均增大;金果榄总皂苷的抗氧化活性随其浓度的增大而递增。     

放线菌类培养滤液体外自由基清除和抗氧化活性的研究

本研究了60种放线菌类培养滤液体外自由基清除和抗氧化活性．这60种放线菌类按阿拉伯数字的顺序被编号．分别采用化学反应抑制自由基产生的化学测定法和抑制红细胞溶血的生物测定法．结果显示2#、41#、45#、52#和54#同时具有高的羟自由基和超氧阴离子的清除活性，以及抑制红细胞溶血能力；36#仅有羟自由基清除活性；44#有超氧阴离子的清除活性，同时有抑制红细胞溶血能力．由此估计抑制红细胞溶血与超氧阴离子的清除活性有关，而与羟自由基清除活性无明显的关系．     

续断皂苷类成分的体外抗氧化活性研究

采用清除二苯代苦味酰基（ＤＰＰＨ）自由基、清除［２,２－连氨－（３－乙基苯并噻唑啉－６－磺酸）二氨盐］（ＡＢＴＳ）自由基和铁离子还原／抗氧化能力（ＦＲＡＰ）测定方法评价续断总皂苷及其主要组成成分川续断皂苷Ⅵ的体外抗氧化活性．结果显示续断总皂苷的抗氧化活性显著优于川续断皂苷 Ⅵ,ＤＰＰＨ 自 由 基 半 数 清 除 率ＩＣ５０分 别 为 ０．９和 ３ ｍｇ·ｍＬ－１,ＡＢＴＳ自由基 的ＩＣ５０ 分 别 是 ０．２５ 和 ２ｍｇ·ｍＬ－１．ＦＲＡＰ 法测得续断总皂苷铁离子的 还原能力相当于 ８８．６７ ｍｍｏｌＦｅＳＯ４,川续断皂苷Ⅵ相当于７．０２ｍｍｏｌＦｅＳＯ４．续断总皂苷和川续断皂苷Ⅵ具有一定的抗氧化能力,且呈明显的量效关系．      

文冠果种仁总皂苷的提取纯化及其抗氧化活性

研究了超声波辅助提取文冠果种仁中总皂苷的工艺条件,并探讨了大孔树脂分离纯化总皂苷的参数以及文冠果总皂苷的体外抗氧化活性。以乙醇为提取剂,通过单因素和正交实验考察了提取剂浓度、提取温度、料液比、超声功率对总皂苷提取的影响。结果表明:乙醇的体积分数70%、提取温度50℃、料液比1∶20、超声功率140 W时,提取物中总皂苷含量最高,达2.69%。采用XAD-16大孔树脂分离纯化文冠果种仁总皂苷,其最佳条件为:静态吸附与解吸时间分别是12h和4h,洗脱剂乙醇的体积分数70%;上样液密度0.12mg/mL(pH=4),上样流速10mL/min,上样液体积与柱体积比1.5,纯化后的总皂苷浓度有较大提高。以Vc作对照,研究文冠果种仁总皂苷的抗氧化活性,结果表明其还原能力和对羟自由基的清除作用高于Vc,清除DPPH自由基和对O-2自由基的能力比Vc要弱。     

有氧耐力训练对大鼠血液脂质过氧化抗氧化能力的影响

自由基又称游离基，是指外层轨道上含有—个或—个以上未配对的电子、原子、离子或基团，即有奇数电子的分子、原子、离子或基团。1956年Harman首次提出自由基学说，多不饱和脂肪酸（PUFA）在自由基和其它一些氧化引化剂作用下，产生脂质过氧化物，从而产生更多的脂质过氧化自由基，而且通过Fe、Ca等过渡金属离子，引起自由基的连锁反应。当自由基产生过多（剧烈运动时）或机体清除能力下降时，自由基可造成许多生物分子如蛋白质、核酸、膜不饱和脂肪酸的损伤，而耐力训练可以改善机体内的SOD含量及总抗氧化能力，从而降低自由基对机体造成的损伤。     

食用菇多糖提取物体外抗氧化性能研究

香菇和鸡腿菇分别经热水浸提,反复醇提、洗涤、真空干燥后得到两种多糖提取物。通过多糖抗食用油脂的氧化作用、利用Fenton反应检测对羟基自由基(.OH)的清除作用、对邻苯三酚自氧化系统产生的超氧阴离子自由基(O2-.)的清除作用以及在模拟胃液条件下清除NO2-的作用,对这两种不同来源的食用真菌多糖的体外抗氧化活性进行了研究。结果表明:两种多糖提取物都具有体外抗氧化性能,香菇多糖提取物的抗活性氧自由基能力和清除NO2-的能力优于鸡腿菇多糖提取物。     

黑色素对羟基自由基清除活性的研究

利用荧光光度分析法研究了黑色素对羟基自由基的清除活性，羟基自由基由Cu2^ 催化过氧化氢氧化抗坏血酸的反应产生，研究表明在一定浓度范围内，黑色素清除羟基自由基能力与黑色素的初始浓度呈线性关系，不同来源的黑色素对羟基自由基的清除能力具有明显的不同。黑色素与尿酸、硫脲相比是更强的羟基自由基清除剂。     

绞股蓝体外抗活性氧自由基的研究

利用光照核黄素产生活性氧自由基O2 -·,Fenton反应产生·OH自由基,分光光度法研究了绞股蓝粗提物体外清除O2 -·,·OH的作用.实验结果表明,绞股蓝粗提物对O2 -·,·OH自由基有显著的清除作用.     

大枣多糖的提取与抗活性氧研究

为了分析大枣多糖对各类活性氧的清除能力,建立了热水提取-乙醇沉淀-氯仿、正丁醇去蛋白的工艺以提取大枣多糖(JPS),并作了糖的含量测定.用化学发光分析法分别测定提取的JPS对全血化学发光法中的全血白细胞呼吸爆发中产生的活性氧(H2O2、O2(-·)、·OH)、连苯三酚自氧化法产生的O2(-·)(超氧阴离子自由基)、抗坏血酸-Cu2+-H2O2体系产生的·OH(羟氧自由基)以及H2O2-鲁米诺发光体系中的H2O2的清除作用.结果:大枣多糖的得率为0.848%,总糖含量为37.7% .测定JPS清除·OH、O2(-·)、H2O2、白细胞呼吸爆发中产生的氧自由基活性的AOV值分别为109.48、9057.9 、312.01、5.204.结论:JPS具有清除氧自由基的作用,其活性大小与多糖的用量呈正相关.在全血生理环境下,对全血化学发光中活性氧的清除能力最强.     

抗癌、抗衰老、抗辐射有效途径--天然产物清除活性氧

活性氧由于其极活泼的化学活性及强致癌、致心血管类疾病、炎症及促进衰老等作用而引起人们的关注.活性氧,也叫氧自由基,其种类繁多,包括超氧阴离子自由基、过氧化氢自由基、羟基自由基、烷基氧、烷过氧基和一氧化氮基等,尤其羟自由基(OH)是极强的氧化剂,它在所有的氧自由基中致癌能力最强、毒性最大、化学活性极其活泼,易攻击细胞中脱氧核糖核酸DNA的碱基使DNA损伤.活性氧自由基所诱导的生物大分子损伤是细胞癌变、衰老和死亡发生的引发剂.有关研究表明,从动植物、水果、蔬菜中萃取出的无毒有效的天然产物,具有清除氧自由基维持健康细胞功能的效果.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

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     

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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