18种中草药抗氧化活性的比较研究

采用分光光度法研究了18种中草药的抗氧化活性,测定了它们的乙醇提取液对DPPH(1,1-二苯基-2-苦肼基自由基)的清除作用. 其中杭白菊、虎杖、白芍、女贞子和龙井茶等5种中草药对DPPH的清除作用都在80%以上,具有较强的抗氧化作用,尤其杭白菊高达93.17%.     

16种中草药提取物的抗氧化活性研究

以无水乙醇、50%乙醇水溶液和水为提取剂,分别超声提取16种中草药,并运用3种抗氧化活性评价方法对各提取液的体外抗氧化能力进行了测定和评价.结果表明:红景天、何首乌、肉苁蓉的乙醇提取液对DPPH·、·OH和·O2-自由基都具有较强的清除能力;石榴皮的无水乙醇、50%乙醇水溶液和水3种提取液对DPPH·和·O2-自由基具有较强的清除能力;陈皮、丹参的水提取液对DPPH·和·O2-自由基也具有较强的清除能力;所有中草药的水提取液对·OH自由基的抑制率均较低.     

5种黔产清热类中草药抗氧化性的研究

共选取5种黔产清热类中草药射干、头花蓼、板蓝根、龙胆草、栀子,测定了其水提取液和乙醇提取液对自由基.OH和DPPH.的清除能力,并采用IC50对其抗氧化能力进行评价。本实验还以烘箱试验来研究这些中草药抗菜籽油和猪油氧化的作用。结果表明,这5种清热类中草药对.OH和DPPH.均具有一定抗氧化作用,并且能很好地抑制菜籽油和猪油氧化。但龙胆草对猪油有一定的促氧化作用。     

7种黔产补益类中草药抗氧化性的研究

共选取7种黔产补益类中草药白术、太子参、何首乌、淫羊藿、麦冬、石斛、黄精,测定其水提取液和乙醇提取液对自由基.OH、O2-.和DPPH.的清除能力,并和维生素C的抗氧化能力进行比较,对其抗氧化能力进行评价.本实验还以烘箱试验来研究这些中草药抗菜籽油氧化的作用.结果表明,这7种补益类中草药对.OH、O2-.、DPPH.均具有一定抗氧化作用,并且能很好地抑制菜籽油氧化.     

改善记忆中草药与核桃肽的相互作用

选取5种具有改善记忆作用的传统中草药(人参、远志、茯苓、龙眼及银杏叶),分别水提得到相应的活性成分,考虑提取效果和重复性,选择3种活性成分与核桃多肽进行相互作用,研究所得复合物的理化特性与抗氧化活性.首先,通过含量和抗氧化测定,发现所提取的中草药活性成分均具有抗氧化、清除自由基功效;然后,以蛋白回收率和抗氧化活性为指标优化核桃酶解工艺,分析最佳酶解液的总氨基酸组成,并借助抗氧化性评价和荧光光谱法研究中草药活性成分与核桃多肽的交互作用,探讨不同相互作用条件(如配比、温度、pH值等)对交互作用的影响.结果表明,中草药中提取的活性成分会使核桃多肽发生荧光猝灭,说明两类物质发生了交互作用,且在抗氧化功效上有协同作用.通过对交互作用影响因素的探讨,发现合适的中草药活性成分与核桃多肽配比有助于增进协同效果,温度、pH值对活性成分和多肽交互作用的影响较为显著.研究结果可为相关产品生产时中草药活性成分与多肽类物质的复配提供一定的参考.     

治疗高血压病中草药中微量元素的主成分分析

采用主成分分析法对7种治疗高血压的中草药中的微量元素进行分析,获得治疗高血压的中草药中微量元素之间的相关关系,并对这7种中草药进行了综合排名,得到了7种中草药的质量优劣,分析总结出了微量元素的作用,研究对治疗高血压中草药的研发提供一定的理论依据。     

米口袋清除自由基活性及其成分研究

为了研究中草药米口袋的清除自由基活性及其成分,用2∶1的甲醇:氯仿超声提取米口袋成分,并用石油醚、乙酸乙酯和正丁醇依次进行萃取,利用DPPH法、邻二氮菲-Fe2 氧化法和AP-TEMED法进行清除自由基活性实验,同时与合成抗氧化剂BHT进行对照。结果显示乙酸乙酯提取物(EAF)具有最高的清除自由基活性,大于人工合成抗氧化剂BHT。利用硅胶,RP-18和Sephadex LH-20对其进行活性追踪分离,得到3种纯的清除自由基活性成分。利用1D、2DNMR和ESI-MS对其结构进行鉴定。结果显示为槲皮素-3-O-葡萄糖甙,芹菜素和4',7-二羟基黄酮。抗氧化活性大小顺序为槲皮素-3-O-葡萄糖甙>芹菜素>4',7-二羟基黄酮>EAF>BHT。含酚羟基化合物的清除自由基活性与其结构密切相关。活性大小主要取决于酚羟基的数目。本研究结果证明:米口袋及其活性成分具有很强的清除自由基作用。可作为一种高效的新型清除自由基天然食品添加剂使用,具有广泛的应用前景。     

几种豆科中草药的电化学指纹图谱鉴别

目的:应用电化学振荡技术测定几种豆科中草药电化学指纹图谱,研究同科不同属的中草药指纹图谱的群集特征.方法:在锰离子催化的振荡反应体系中,以中草药为反应耗散底物,应用电化学工作站测定不同中药的电化学指纹图谱.结果:几种豆科中草药电化学指纹图谱各具特色.结论:利用电化学指纹图谱技术鉴别豆科几种中草药是可行的.     

五种中草药提取液对细菌作用效果初探

选取银杏、厚朴、野菊花、苦参、石菖蒲五种中草药,利用95%酒精提取其活性成分,进行抑菌、杀菌活性测定.结果表明,在供试质量浓度0.05g/mL时,此五种中草药对大肠杆菌、枯草杆菌、金黄色葡萄球菌的抑菌率均在86%以上;在供试质量浓度0.01g/mL时,作用时间为5min,五种中草药对大肠杆菌、金黄色葡萄球菌的杀菌率均在94.5%以上,杀菌效果显著.不同中草药对同一细菌的抑制作用有一定差异,同一中草药对不同细菌的抑制作用亦存在着较大差异.中草药的杀菌率随着浓度增大、着用时间延长,杀菌率随之增大.但五种中草药对枯草杆菌均无杀菌效果,其原因有待进一步探讨.     

中草药及其生长土壤中铅元素含量相关性研究

实验测定了甘肃定西地区的几种中草药药用部分的Pb元素含量及这几种中草药根系部分土壤中Pb元素的含量，通过两者的含量对比，考察了Pb元素从土壤到中草药中的生物迁移相关性．比较了微波消解和高温灰化两种样品预处理方法，选择了微波消解法．用原子吸收火焰法测定Pb含量，结果表明：所测中草药药用部分的Pb元素含量明显低于土壤中的含量，说明中草药对土壤中的Pb元素有微弱生物迁移作用。     

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

正~~