小剂量辐射对红细胞膜流动性的影响

本实验以人红细胞膜为材料,使用DPH荧光探针,测定红细胞膜的荧光偏振度、微粘度,可反映出细胞膜流动性的大小,因而能定量地反映出膜脂与膜蛋白的运动状态。以1GY、0.5Gy、0.25Gy小剂量γ射线照射红细胞膜后进行测定,结果照射组(三组)的荧光偏振度、微粘度、细胞膜流动性与对照组无明显差异,表明小剂量γ射线照射后,细胞膜的流动性无明显变化。     

有机溶剂对大肠杆菌细胞膜的影响

通过对甲苯、四氯化碳、正己烷、邻苯二甲酸二乙酯4种有机溶剂对大肠杆菌K12存活率、细胞膜电位、通透性和脂肪酸组成的影响研究发现:大肠杆菌对正己烷、邻苯二甲酸二乙酯耐受性较对四氯化碳和甲苯的耐受性强;在有机溶剂刺激下,可以看到细胞膜电位的降低及细胞膜通透性的增加,细胞膜饱和脂肪酸比例增加.在加入0.3%四氯化碳30min后,细胞膜电位下降了16.3%,通透性增加34.5%,饱和脂肪酸比例达到38.7%.因此,大肠杆菌通过细胞膜的变化来适应有机溶剂的刺激.     

肺腺癌A549细胞膜上磷脂翻转酶的存在与顺铂耐药性

为证实肺腺癌细胞膜上是否存在磷脂翻转酶,将含有NBD-PE荧光探剂的脂质体与A549和A549/DDP细胞融合,根据外膜NBD-PE的荧光强度变化来检测细胞膜上磷脂翻转酶的存在及其活性.当含有NBD-PE的A549和A549/DDP细胞在保温0,30,60和90min时,测定外膜NBD-PE的结果表明,A549细胞的NBD-PE荧光强度在上述不同时间保温后分别为0%,1.4%,2.9%和7.8%;而A569/DDP细胞则相应为0%,10.5%,15.5%和18.3%,证实A549肺腺癌细胞膜上存在磷脂翻转酶.而且,具有抗药性的A549/DDP细胞膜上的磷脂翻转酶的活力明显高于药物敏感的A549细胞.用多药耐药逆转剂Verapamil(20μmol/L)在37℃处理A549/DDP细胞60min后测定其结果又表明,NBD-PE在膜外侧的增加较对照降低了25.0%.而用治疗肺腺癌的特异性抗癌药cisplatin(255μmol/L)处理时,NBD-PE在膜外侧的增加降低了31.6%,且随cisplatin的浓度增加进一步降低达79.4%.这与肺腺癌细胞的耐药性可能相关.     

磁场对酿酒酵母微观结构及膜脂流动性的影响

以磁场为外加物理场,采用恒定磁场及循环磁处理方式对酿酒酵母进行处理,研究酿酒酵母微观结构及细胞膜流动性的变化.通过透射电子显微镜观察不同磁感应强度恒定磁场处理后酿酒酵母的微观结构.研究发现恒定磁场可以促进酵母细胞的生长,群体中以具有中央大液泡为特征的成熟细胞所占比率增大,同时线粒体呈现适应性膨大、增生.利用原子力显微镜观察循环磁处理下酵母细胞的三维结构,发现细胞壁表面出现皱缩、穿孔,胞质外流.用荧光偏振法对两种处理方式下细胞的膜脂流动性进行测定,发现不同强度恒定磁场处理后,膜脂各向异性下降,流动性增强,0.05T磁感应强度下各向异性值下降3.57%,而循环磁处理后各向异性值比对照提高了8.46%,膜脂流动减慢,证实细胞膜为受到磁场作用的亚细胞结构.     

细胞选择性穿膜肽的穿膜效果研究

细胞穿膜肽是一类能够穿透细胞膜并且不损坏细胞膜结构的小分子多肽,该多肽一般由不多于30个氨基酸组成.针对FITC标记的具有肺癌或肝癌细胞选择性的两种穿膜肽,设置不同浓度梯度,分别处理多种肿瘤细胞,荧光显微镜下观察不同作用浓度下细胞中绿色荧光的强弱,并通过流式细胞仪检测含有荧光的细胞数.结果表明:两种细胞穿膜肽具有不同的细胞选择性. CPP33在作用浓度为10μmol/L时能观察到较强的荧光选择性,流式细胞仪检测含有荧光的细胞数约大于50%,CPP44在作用浓度为10μmol/L时能观察到较强的荧光选择性,流式细胞仪检测含有荧光的细胞数约大于60%.并且随着作用浓度的增加,两种细胞中含有荧光的细胞数不断上升.因此这种针对肿瘤细胞的选择性穿膜肽可能为小分子药物在体内的精确递送提供一种新的方法.     

龙葵多糖对H22荷瘤小鼠红细胞膜功能的影响

研究龙葵多糖对H22荷瘤小鼠红细胞膜功能的影响.采用DPH荧光探针标记荧光分光光度计测定红细胞膜的流动性,比色法测定红细胞膜表面膜封闭度、SA、SOD的含量.龙葵多糖各剂量组都能够降低H22荷瘤小鼠红细胞膜的微黏度,提高细胞膜脂流动性,提高红细胞膜重新封闭的能力,升高荷瘤小鼠红细胞膜唾液酸及超氧化物歧化酶的含量.龙葵多...     

蟾酥对活体家兔体内大肠杆菌抑制作用研究

蟾酥对活体家兔体内大肠杆菌(Escherchia coli)抑菌作用的原因可能是抑制了大肠杆菌细胞壁粘肽合成酶的活性,使蛋白质合成受阻,破坏了细胞膜的通透性,抑制了菌体的增长.实验中向家兔耳缘静脉注射1 mL浓度为2 mg.mL-1的蟾酥药液后,观察活体家兔体内大肠杆菌菌落的变化.结果表明,给带菌家兔注射蟾酥药液后,大肠杆菌的平均菌落数由17.66个降到1.5个.     

金基质的固体表面荧光法测定痕量Mn2+

以金片作为固体基质,通过自组装方式把荧光物质1-萘胺乙酸(NAA)间接组装在金表面,制备具有荧光特性的NAA/Cys/Au自组装膜.利用在酸性介质中,Mn2 可使NAA/Cys/Au自组装膜表面荧光产生猝灭,且荧光猝灭程度和Mn2 浓度在5.0×10-6～3.0×10-5 mol·L-1范围内呈现良好的线性关系,从而建立利用固体表面荧光检测Mn2 的新方法,其检测下限为9.64×10-7 mol·L-1.荧光被Mn2 猝灭后的自组装膜,可在NaOH溶液中实现膜表面荧光的再生.     

大豆磷脂脂质体与绵羊红细胞膜相互作用的研究(Ⅱ)

用超声法制备大豆磷脂小单层脂质体，低渗溶血法制备绵羊红细胞膜。在一定条件下，将脂质体与红细胞膜温育一定时间后，离心去掉脂质体，用正己烷－异丙醇，提取膜总脂质，用高效液相色谱法分离测定温育前后膜脂组成。结果表明，温育后红细胞膜的磷脂酰胆碱与鞘磷脂物质的量之比（ｎｐｃ／ｎｓＭ）明显增加，这是影响膜流动性的重要参数。上述结果与作者以前用ＤＰＨ荧光偏振技术测定的同样条件下膜流动性变化完全一致。因此，很好地从分子水平上解释了与大豆磷脂脂质体温育后，红细胞膜流动性的增加。     

改进法制备大肠杆菌膜囊及其电镜观察

使用改进方法成功地制得大肠杆菌膜囊。该膜囊为一封闭的、不合任何细胞质组织的、仅由细胞膜构成的囊状结构。少数膜囊外仍保留部分外膜成份。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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