枸杞多糖的研究与应用

枸杞多糖是枸杞中主要的生物活性成分之一,因具有抗氧化、免疫调节、抗肿瘤等多种功能作用而成为近年来研究的热点。详细介绍了枸杞多糖的制备、生物活性作用及其开发利用现状。枸杞多糖的制备过程包括提取、分离与纯化。提取方法有水提醇沉法、碱液提取法、超声波提取法、微波辅助法等;分离与纯化方法主要有Sevage法、三氯乙酸法、蛋白酶法、活性炭脱色、聚合物-盐双水相系统等,主要是去除多糖中游离蛋白质、色素等杂质,再通过分级沉淀、纤维素离子交换柱层析和凝胶柱层析方法进一步纯化得到单一多糖。此外,还对近年来枸杞多糖在医药、食品、畜牧与饲料等领域的开发利用进行了较详细介绍,并对今后的研究方向进行了展望,旨在为枸杞多糖的进一步研究与开发提供参考。     

茶树花多糖研究进展

茶树花与茶叶同根共生,但往往被视为茶树的废弃物,不能很好地加以利用,从而造成资源的浪费与损失。茶树花含有丰富的活性物质,其中茶树花中的多糖成分与茶叶中含有的多糖成分基本相同,但含量明显高于茶鲜叶。茶树花多糖具有降血糖、抗氧化、免疫调节作用及抗肿瘤、肝保护、抗凝血等多种生物活性,是非常宝贵的新资源食品。茶树花多糖主要的提取方法包括溶剂提取法、酶法提取、微波辅助提取和超声辅助提取法。提取出的茶树花粗多糖,一般需要经过脱蛋白、脱色、色谱柱分离等纯化工艺,得到纯净的茶树花多糖。目前,围绕茶树花多糖的研究报道较少,值得对其进行深入研究。聚焦茶树花这一新资源食品,围绕茶树花多糖的生物活性、提取方法、分离纯化方法等方面进行阐述,以期为研究茶树花及其多糖活性物质的开发利用提供新的研究思路。     

糖脂康多糖的分离与纯化研究

目的:研究糖脂康多糖的提取、分离与纯化方法,并筛选出糖脂康多糖脱蛋白、脱色的最佳方法。方法:采用水提醇沉法提取分离糖脂康多糖,以提取多糖物质多糖损失率、蛋白质去除率为测定指标,分别考察不同实验方法对糖脂康多糖脱蛋白、脱色的影响。结果:三氯乙酸脱蛋白法为糖脂康多糖脱蛋白的最佳方法,活性炭脱色法对糖脂康多糖的脱色效果优于过氧化氢脱色法。结论:糖脂康粗多糖的纯化,脱蛋白、脱色方法的优化为进一步研究糖脂康多糖的生物活性提供了基础。     

甘薯多糖SPP-Ⅰ的制备与结构初步研究

研究采用水提醇沉法提取甘薯粗多糖,进行单因素试验考察,用正交法优化工艺.再经DEAE-纤维素-52阴离子交换柱和Sephadex G200凝胶柱对所得粗多糖进行层析纯化,得到甘薯多糖组分SPP-Ⅰ.应用苯酚硫酸法测定多糖百分含量,HPLC法测定多糖分子质量,紫外光谱、红外光谱、甲基化衍生结合GC-MS分析多糖结构.结果表明甘薯多糖最优提取工艺为提取温度90℃,提取时间3 h,液料比40∶1,提取次数3次.甘薯多糖SPP-Ⅰ总糖百分含量分别为97. 61%,分子质量为245ku,紫外光谱扫描结果显示无核酸和蛋白质吸收峰,红外光谱扫描结果表明含有多糖类物质的特征吸收峰,结合甲基化和GC-MS分析初步确定甘薯多糖SPP-Ⅰ是具有1→3、1→3→6糖苷键结构的α-葡聚糖.     

莪术多糖的分离纯化

研究莪术多糖分离纯化的最佳条件,优化莪术多糖的提取纯化工艺,为进一步探讨莪术多糖的生物活性奠定基础.莪术经热水提取,酒精沉淀,脱色,脱蛋白得粗多糖.粗多糖用50%、75%乙醇分级沉淀得2个级分CZ1、CZ2,进行DEAE-纤维素柱层析.调节DEAE-纤维素的pH值,比较洗脱曲线的不同.CZ1经DEAE-纤维素柱层析得到1个组分,CZ2在酸性、中性条件下层析得2个组分,在碱性条件下得1个组分,随pH升高,回收率降低,纯度增高.各纯化得到的多糖组分经纸层析、琼脂糖凝胶电泳鉴定为单一成分.实验证明,pH是影响层析的一个重要因素,因此莪术多糖的最佳纯化pH值为7.0.     

白术多糖的研究进展

白术多糖具有多种重要的生物活性和功能,是目前药物开发和研究的热点之一.对白术多糖提取、分离纯化、结构分析和生物活性的研究现状进行综述,并指出研究存在的问题和今后的研究方向.     

虎奶菇中多糖的提取工艺、结构分析和生物活性研究进展

虎奶菇是一种具有大型菌核且营养丰富的食药两用型担子菌,其在民间常被用于治疗哮喘、感冒发烧、胃病等常见病症,具有显著提高人体免疫力的功能。有关虎奶菇中活性物质的研究文献逐年增多,对近年来虎奶菇中的一种活性物质——多糖的提取和纯化技术、结构鉴定方法、生物活性等方面进行了较为详细的总结和概括,可为虎奶菇活性多糖的进一步深入研究和产品开发提供参考。     

双孢蘑菇菇柄中多糖、核酸等成分的提取利用

废弃的双孢蘑菇菇柄富含多糖、核酸等活性物质,应获得更好的开发利用。本文就改进食用菌多糖的提取纯化工艺和简化核酸类物质的提取纯化工艺,采用膜分离技术,获得较高纯度的多糖产品、核酸产品进行了探索。     

金樱子不同部位多糖的提取

对金樱子多糖的分离纯化方法作了探讨，筛选出了较佳的工艺条件，通过紫外分光光度法，对金樱子的果肉、籽、两者混和物中多糖提取的含量进行比较。找出最佳金樱子多糖提取部位。     

仙人掌多糖的超滤膜分离提取及其影响因素

应用不同截留分子质量的超滤膜对仙人掌多糖浸提液进行分离、纯化和浓缩,并分析了超滤压力、超滤温度、纯化时间、料液体积流量、浓缩倍数等对超滤过程的影响,得出了最适宜的操作条件.研究结果表明,当选用截留分子质量为10000 ku的超滤膜、超滤压力为0.20MPa、超滤温度为25℃、料液体积流量控制在0.04~0.05 L/min、浓缩倍数为5~7倍时,粗多糖得率达0.95%.与传统的真空浓缩法相比,超滤浓缩法的粗多糖得率较高,所得多糖的品质也得到了改善,减轻了后续工艺进一步分离纯化多糖的负担.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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