人老化红细胞囊泡的分离及其特性研究

本文报道了人红细胞在体外老化(37℃.48h)过程中会自然形成并释放的囊泡为不均一的群体,经Dextran-T70不连续密度梯度离心后可明显分成三种组分.囊泡主要集中在组分Ⅱ和Ⅲ中,而组分Ⅰ除了囊泡外还含有膜和膜碎片.这三种囊泡组分在流动性、封闭度等性质上有明显差异.值得引起注意的是,囊泡的荧光光谱与正常红细胞膜相比变化较大,红移22nm左右,这提示了囊泡膜脂的结构和组分与红细胞有较大差异.     

微量元素硒对红细胞老化的保护作用

红细胞老化过程中,释放囊泡,增加脆性以及减少酶活性等等均是细胞衰老的征状。本文在前文的基础上,探讨了微量元素硒对红细胞老化的保护作用。发现在红细胞老化体系中补充适量 Na_2SeO_3(0.04～0.64ppm)后,红细胞延缓释放囊泡,溶血减少以及膜上 AchE 脱落减少,而过量的 Na_2SeO_3(6.4 ppm 以上)对红细胞则有一定的损伤作用。用电子顺磁共振(ESR)波谱仪分别测定了红细胞膜,Na_2SeO_3溶液以及外加硒红细胞膜的 ESR 谱。结果表明,外加硒红细胞膜的 ESR 谱与红细胞膜和 Na_2SeO_3溶液均不相同,其特征峰的 g 值在2.0760左右。这提示了 Na_2SeO_3对红细胞膜的作用可能是以膜结合硒的形式进行的。     

微量元素硒对红细胞老化的保护作用

红细胞老化过程中,释放囊泡,增加脆性以及减少酶活性等等均是细胞衰老的征状.本文在前文的基础上,探讨了微量元素硒对红细胞老化的保护作用.发现在红细胞老化体系中补充适量Na_2SeO_3(0.04～0.64ppm)后,红细胞延缓释放囊泡,溶血减少以及膜上AchE脱落减少,而过量的Na_2SeO_3(6.4 ppm以上)对红细胞则有一定的损伤作用.用电子顺磁共振(ESR)波谱仪分别测定了红细胞膜,Na_2SeO_3溶液以及外加硒红细胞膜的ESR谱.结果表明,外加硒红细胞膜的ESR谱与红细胞膜和Na_2SeO_3溶液均不相同,其特征峰的g值在2.0760左右.这提示了Na_2SeO_3对红细胞膜的作用可能是以膜结合硒的形式进行的.     

氧化甾醇-磷脂脂质囊泡的制备及特性研究

 氧化甾醇3,19–二羟基-胆甾烷-24-酮（DHCO）和3β,5α,6β-胆甾烷三醇（Triol）替代胆甾醇与大豆磷脂形成脂质囊泡的性质研究。采用乙醇注入法制备脂质囊泡,通过测定脂溶性及水溶性荧光探针在脂质囊泡中的荧光强度变化,考察囊泡膜流动性及通透性;通过测定脂质囊泡中游离DHCO及结合DHCO的浓度考察DHCO与磷脂的结合率;考察DHCO/磷脂比例、超声条件对脂质囊泡粒径大小和分布的影响。结果表明,DHCO、Triol与磷脂形成的脂质囊泡与胆甾烷（CHOL）-磷脂脂质囊泡的膜流动性无明显差异,但膜通透性稍有增大。DHCO与磷脂的结合率为8258%。DHCO、Triol与大豆磷脂经简单工艺即可形成脂质囊泡。可通过调节DHCO/磷脂比例、超声条件获得具理想粒径和外观的脂质囊泡。氧化甾醇数量庞大,其作为脂质囊泡的新型“流动性缓冲剂”有巨大的发展潜力。     

几种血液病人红细胞膜蛋白组分的比较研究

为研究几种血液病人和正常人的红细胞膜蛋白的差异,采用ＳＤＳ－ＰＡＧＥ对红细胞影泡电泳。结果发现：一生溶贫病人膜蛋白的电泳图谱与正常人基本相似、膜蛋白组分含量属正常;贫血病人的膜蛋白中带４．１与带３的比值较正常的低,且带４．２下出现新带,与骨髓病主粗关的病人膜蛋白各组分变化较大。     

玉米根细胞正面向外和内翻外质膜囊泡的分离

利用水双相分配分离法从玉米根细胞提取原生质膜囊泡。其质膜成分特异的K~+,Mg~(2+)—ATP酶活性比膜粗提液高1.67倍。其他细胞器标记酶活性在质膜组分中很低或没有。特异染色电镜形态学定量统计表明质膜组分中90％以上是质膜囊泡。去污剂刺激ATP酶活性实验证明,约92％囊泡是正面向外的。应用此法也证明NAD(P)H—氧化酶可能是跨膜存在的,其催化Fe~(3+)还原的位点可能在膜的内侧。应用高盐冻—融法并结合水双相分配分离法处理正面向外囊泡,可获得内翻外质膜囊泡,实验证明它不仅纯度高而且封闭。     

超重女性有氧运动对红细胞代谢的影响作用

有氧运动是人体在氧气充分供应的情况下进行的体育锻炼,红细胞代谢时可运输氧气,研究超重女性有氧运动对红细胞代谢产生的影响作用具有十分重要的意义。对64名超重女性进行为期三周的有氧运动。通过流式细胞检测法检测超重女性体内红细胞膜的PS外翻量,对有氧运动前后的血脂、PS外翻及Na+K+-ATPase和Ca2+Mg2+-ATPase酶三维活性进行检验。实验结果表明:有氧运动干预之前,轻度超重组女性体内的PS外翻量与其余两组有明显的差别(P≤0.05),HDL在轻度超重组和重度超重组之间有明显的区别;有氧运动干预后,Na+K+-ATPase的活性有显著提高(P≤0.05),红细胞膜的PS外翻量虽然有降低的趋势,但差异不显著。说明在红细胞脂质代谢紊乱的初期,红细胞膜PS外翻量比血脂指标更能体现超重女性的体重发展情况。有氧运动能够有效提高红细胞膜膜Na+K+-ATPase酶的活性,提高红细胞膜PS的外翻量,同时加快红细胞的代谢速度。     

曲率模量不同的两组分膜泡形状方程的数值解

采用变分法讨论了旋转对称情况下曲率模量不相同的两组分膜泡的欧拉-拉格朗日形状方程及其边界条件。通过双向"打靶法"数值求解了两组分膜泡在确定边界条件下的形状方程,计算了不同平均曲率模量比εκ和线张力系数λ下的平衡形状。阐述了不同εκ和λ下平均曲率模量不相同的两组分膜泡的形状变化,导致这种变化的原因是膜泡两组分的曲率能和线张力能相互竞争的结果。计算结果说明数值计算方法合理可行,此数值解可进一步研究与实验相关的两组分膜泡问题。     

人红细胞老化对膜结构及组分的影响

目前认为细胞老化与其膜结构及组分的改变有密切关系。本文探讨了在不同条件下老化(体内或体外)的红细胞对其膜结构和组分的影响。结果表明,完整红细胞老化后其膜流动性均明显下降(P<0.01)而收缩蛋白含量显著增加(P<0.01)。但值得注意的是,分离的红细胞膜在体外老化(37℃,24小时)后收缩蛋白含量却显著减少(P<0.05)。关于老化红细胞膜上收缩蛋白含量变化的原因,本文作了初步讨论。     

人红细胞老化对膜结构及组分的影响

目前认为细胞老化与其膜结构及组分的改变有密切关系。本文探讨了在不同条件下老化(体内或体外)的红细胞对其膜结构和组分的影响。结果表明,完整红细胞老化后其膜流动性均明显下降(P<0.01)而收缩蛋白含量显著增加(P<0.01)。但值得注意的是,分离的红细胞膜在体外老化(37℃,24小时)后收缩蛋白含量却显著减少(P<0.05)。关于老化红细胞膜上收缩蛋白含量变化的原因,本文作了初步讨论。     

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