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.     

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。     

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.     

基于大肠杆菌MG1655载体矿化合成纳米硒的研究

根据生物矿化策略,以不同质量浓度的Na_2SeO_3溶液作为硒源,利用大肠杆菌MG1655生物还原Na_2SeO_3制备纳米硒。研究Na_2SeO_3质量浓度对大肠杆菌生长曲线的影响,用氢化物原子荧光光谱法(HG-AFS)测定Na_2SeO_3的还原效率,进一步利用扫描电子显微镜(SEM)、X线衍射仪(XRD)和傅里叶红外光谱(FT-IR)等仪器对产物进行了相关表征。结果表明:大肠杆菌MG1655能将Na_2SeO_3大量矿化为粒径基本在100~250 nm左右的红色单质纳米硒颗粒,且对各质量浓度下的Na_2SeO_3的还原率均在50%以上。     

硒酵母中三种含硒馏分的生物活性研究

本文采用超声粉碎硒酵母,将其超速离心所得上清液通过Sephadex—G25分子筛色谱柱,分离得到三个含硒馏分(P_1;P_2;P_3)。用T_3菌生物发光和电子自旋共振(ESR)技术研究了它们对As(Ⅲ)毒性的拮抗作用和对脂质过氧自由基的清除作用。实验结果表明其生物活性大小为P_3>P_1>P_2>Na_2SeO_3,并对三个含硒馏分的结构进行了讨论。     

硒对衣藻细胞群体生长的促进作用及其对汞的拮抗

作者以衣藻为材料,观察硒对其群体生长的促进作用以及硒对汞的拮抗。结果表明,1ppm及5ppm的SeO_2对衣藻细胞群体的生长有促进作用,细胞的耗氧量及谷胱甘肽过氧化物酶的活性均高于对照组(不含SeO_2)。但如培养液含硒量为10ppm以上时,衣藻群体的生长就将受到抑制。衣藻细胞在含HgCl_21.5ppm的培养液中48小时后几乎全部褪色死亡,但在含HgCl_2 1.5ppm,同时含SeO_2 5ppm的培养液中,衣藻细胞生长正常,群体生长曲线和不含HgCl_2和SeO_2的培养液(对照组)相似,说明5ppm SeO_2可以拮抗1.5ppm HgCl_2的毒性。     

微量Se保护细胞膜和细胞内DNA免受~1O_2损伤的研究

本文利用亚甲蓝光敏化产生~1O_2,对~1O_2的荧光检测法做了研究;利用滤膜过滤法研究了硒化合物保护NIH小鼠肾细胞DNA免受~1O_2损伤的作用;利用~3H-TdR掺入法研究了Na_2SeO_3对~1O_2抑制Wistar大鼠骨髓细胞DNA合成的作用;利用TBA法检测细胞脂质过氧化作用,观察到Na_2SeO_3抑制~1O_2诱导的细胞脂质过氧化的作用.Na_2SeO_3起保护作用的最适宜浓度范围为0.01～1.00μmol/L,高浓度的Na_2SeO_3表现出毒性作用.     

红细胞膜的ESR研究——冷冻固化新鲜膜的各向异性及氧化特性

冷冻干燥膜和冷冻固化新鲜膜都得到各向异性的ESR谱,表明红细胞膜之间存在电磁相互作用。经超氧阴离子O_2~-氧化后的红细胞膜在ESR谱图中出现了g=2.0062的吸收峰,故本文还对O_2~-与细胞膜的相互作用了实验研究。     

红细胞膜的ESR研究——冷冻固化新鲜膜的各向异性及氧化特性

冷冻干燥膜和冷冻固化新鲜膜都得到各向异性的ESR谱,表明红细胞膜之间存在电磁相互作用。经超氧阴离子O_2~-氧化后的红细胞膜在ESR谱图中出现了g=2.0062的吸收峰,故本文还对O_2~-与细胞膜的相互作用了实验研究。     

红细胞膜氧化损伤的ESR波谱研究

用生化方法对红细胞膜的氧化损伤研究已有较长的历史[1,2]但是借助于ESR手段的研究则相对较少。因为通常人们采用的方式不是极低温,就是借助自旋标记:前者的谱图复杂,分析识别困难,后者的实验局限性大,故只能在膜的局部结构研究中发挥作用[3～5]。由于作者在二年前成功地利用冷冻固化的方法对红细胞膜进行了ESR波谱的研究[3],它可使图谱简化,易于识别,发现了红细胞膜氧化后出现的特异自由基信号。本文就是介绍在此基础上研究红细胞膜氧化损伤的作用机理,研究表明,ESR波谱可以作为红细胞膜内部结构及有关动态机理研究的一种手段。     

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     

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