藏红花花瓣粗多糖的体外抗氧化活性研究

采用水提醇沉法提取藏红花花瓣中的多糖,得率为3.75%.联合蒽酮-硫酸法和DNS法测得多糖纯度为68.34%.对粗多糖的体外抗氧化活性进行测定,结果表明,粗多糖具有一定的抗氧化活性,抗氧化能力指数(ORAC)值为0.572μmol TE/mg;其对ABTS+、DPPH和羟自由基具有一定的清除能力,半数清除浓度EC50分别为76.26μg/mL、165.5μg/mL和880.4μg/mL.     

地黄功能因子提取物体外抗氧化活性及α-葡萄糖苷酶抑制活性研究

通过体外试验，探讨了DHTW抗氧化活性及α-葡萄糖苷酶的抑制活性，为地黄降糖功能因子的开发利用提供理论依据.采用紫外分光光度法(UV)测定DHTW清除DPPH、ABTS等自由基的能力，利用酶标仪测定DHTW抑制α-葡萄糖苷酶的活性.结果表明：(1)DHTW均具有抗氧化活性，质量浓度在0～6 mg/mL内，随着浓度的增加，抗氧化活性也不断增加，当溶液达到一定浓度后，抗氧化性趋于稳定.(2)DHTW的DPPH自由基清除能力IC₅₀值分别为：醇洗脱物DHY(0.087 mg/mL)、粗提物DHC(2.987 mg/mL)、水洗脱物DHS(3.024 mg/mL)，故自由基清除能力表现为：DHY>DHC>DHS.(3)DHTW的ABTS自由基清除能力IC₅₀值分别为：DHY(0.137 mg/mL)、DHC(1.463 mg/mL)、DHS(2.168 mg/mL),ABTS自由基清除率表现为：DHY>DHC>DHS.(4)DHTW对α-葡萄糖苷酶均有明显的抑制作用，其中，DHY有较明显的抑制能力，α-葡萄糖苷酶抑制活性明显优...     

翘鳞肉齿菌多糖的分离纯化及抗氧化活性的研究

为了分离纯化翘鳞肉齿菌多糖,解析其结构特征,并研究其抗氧化活性.运用DEAE-cellulose column进行柱层析分离纯化翘鳞肉齿菌多糖,高效凝胶渗透色谱(HPGPC)方法研究其均重分子量,通过红外光谱解析其结构特征,进一步研究其对羟基自由基(·OH)、1,1-二苯基-2-苦基肼自由基(DPPH-)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+)的清除作用,同时研究了翘鳞肉齿菌多糖在H2O2作用下对PC12细胞的保护能力.其结果显示从四川省小金县翘鳞肉齿菌子实体分离纯化得到一种水溶性杂多糖(SIKP-1)纯品,其重均分量约为2.0×104 Da.通过化学方法研究了不同质量浓度的翘鳞肉齿菌多糖(SIKP-1)抗氧化活性,结果表明:当SIKP-1质量浓度为0.1mg/mL时,其对DPPH-自由基的清除率可达到40.63%;当SIKP-1质量浓度达到0.32mg/mL时,对·OH自由基的清除率可达到51.61%;当SIKP-1的质量浓度为3mg/mL时,对ABTS+自由基的清除率可达69.75%;在细胞生物学实验中,结果显示在用终质量浓度为0.5,1,2 mg/mL的SIKP-1处理下,PC12能免于H2O2的损伤,随着剂量的增加其存活率越高,分别为15.89%,27.60%,29.36%.综上试验结果显示,翘鳞肉齿菌多糖(SIKP-1)具有显著的抗氧化功能,因此可以作为一种理想的抗氧化剂资源.     

红参多糖体外抗氧化的研究

目的:研究不同醇沉浓度提取的红参多糖的体外抗氧化能力,并用Vc作为阳性对照。方法:用紫外分光光度法研究红参多糖和Vc清除DPPH自由基和羟自由基的能力来评价其抗氧化活性。结果:80%醇沉的红参多糖对DPPH自由基、羟自由基清除效果最好,IC_(50)分别为0.81,0.44mg/mL;30%醇沉的红参多糖对DPPH自由基也有清除效果,但相对较弱,IC_(50)为12.74mg/mL;50%醇沉的红参多糖对羟自由基的清除效果最差。结论:红参多糖具有较强的抗氧化作用,其中80%醇沉红参多糖抗氧化作用最强。     

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.     

新疆芍药与窄叶芍药根中多糖含量测定及体外抗氧化活性的研究

为探讨新疆芍药和窄叶芍药根中多糖的含量并评价其多糖体外抗氧化活性。采用水提醇沉法提取多糖,用Sevage法除蛋白、活性碳脱色,并用苯酚-硫酸比色法测定多糖的含量;并采用1,1-二苯基-2-硝基苯肼自由基清除法(DPPH法)和2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二氨盐自由基清除法(ABTS法)对提取的多糖进行体外活性评价。结果显示:纯化后窄叶芍药和新疆芍药的多糖含量达0.82%和0.78%;窄叶芍药和新疆芍药多糖对DPPH自由基的IC50分别为0.07 mg/m L和0.13 mg/m L;而两者对ABTS自由基的IC50分别为0.075 mg/m L和0.096mg/m L。由此可知,本文建立的测定多糖含量的方法简便、准确、重现性好;且窄叶芍药和新疆芍药对清除DPPH与ABTS自由基均具有一定抗氧化活性。     

玉竹多糖的抗氧化作用研究

为研究玉竹多糖的体外抗氧化活性和清除自由基作用,采用体外化学体系研究玉竹多糖对超氧阴离子(O-2·)、羟自由基(·OH)、1,1-二苯基-2苦苯肼自由基(DPPH·)和过氧化氢(H2O2)的清除能力。结果表明:玉竹多糖对超氧阴离子(O-2·)、过氧化氢(H2O2)和1,1-二苯基-2-苦苯肼自由基(DPPH·)具有较强的清除能力,其EC50值分别为0.38 mg/mL(Vc为0.09 mg/mL)、0.65 mg/mL(Vc为0.70 mg/mL)和0.43 mg/mL(Vc为0.06 mg/mL);但对羟自由基(·OH)的清除能力较弱,其EC50值为14.7 mg/mL(Vc为0.34 mg/mL)。玉竹多糖具有较好的体外抗氧化活性。     

蒙药述达格-4抗氧化活性研究

通过建立蒙药述达格-4体外抗氧化活性测定方法,明确述达格-4的抗氧化作用.采用DPPH自由基清除率、FRAP法对Fe3+的还原能力、TEAC法对ABTS自由基的清除率及总抗氧化能力(T-AOC)试剂盒等综合评价述达格-4的抗氧化能力.结果显示,述达格-4浓度为0.32mg/mL时,DPPH自由基清除率为77.08％,I...     

杏鲍菇粗多糖的抗氧化活性研究

对杏鲍菇子实体、菌丝体和发酵液粗多糖清除DPPH自由基、羟自由基的能力、铁离子螯合能力以及还原力进行了比较分析,结果表明:菌丝体、发酵液粗多糖清除DPPH自由基能力较强,清除率EC50值分别为4.15和4.81mg/mL;子实体、菌丝体和发酵液粗多糖清除羟自由基、螯合铁离子的能力较强,羟自由基清除率EC50值分别为1.27、1.31和3.54mg/mL,铁离子螯合能力EC50值分别为3.01、1.53和4.17mg/mL;在一定浓度范围内,多糖浓度增加其清除DPPH自由基、羟自由基的能力以及铁离子螯合能力亦增强,并呈现良好的量效关系.实验浓度范围内,3种粗多糖的还原力均较弱.     

响应面法优化白番红花球茎多糖提取工艺及其抗氧化活性研究

在单因素试验的基础上,以白番红花球茎多糖提取率为响应值,对超声功率、超声时间、液料比三因素进行响应面法优化试验,并通过白番红花球茎多糖对DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基的清除能力,来研究白番红花球茎多糖的抗氧化活性.白番红花球茎多糖的提取最佳工艺条件为：超声功率为428 W、超声时间为45 min、液料比为57.8∶1(mL·g^-1),多糖实际提取率为7.54%.白番红花球茎多糖对DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基均有清除作用,其清除率最高分别可达到78.5%、57.9%、45.3%、79.8%.响应面法优化超声波提取白番红花球茎多糖的工艺合理可行,并且白番红花球茎多糖具有较强的抗氧化活性.     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has