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1.
邻苯二酚与脱氧核糖核酸相互作用的研究   总被引:1,自引:1,他引:0  
用循环伏安法、荧光光谱法、紫外可见光谱法、量子化学方法研究了pH为7.42的磷酸盐缓冲溶液中邻苯二酚与脱氧核糖核酸(DNA)的相互作用,在DNA开链过程中,邻苯二酚与脱氧核糖核酸作用后的荧光光谱曲线、紫外光谱曲线的吸收峰改变较大,循环伏安法峰氧化峰正向移动,电流增大,量化计算表明邻苯二酚位于磷酸基团近侧,邻苯二酚与脱氧核糖核酸主要以静电方式结合。  相似文献   

2.
采用单壁碳纳米管(SWCNTs)-Nafion修饰电极作为工作电极,对邻、间、对硝基苯酚进行同时测定,实现了硝基苯酚异构体不经分离同时测定.邻硝基苯酚(o-NP)、间硝基苯酚(m-NP)和对硝基苯酚(p-NP)的线性范围分别为3.0×10-5~9.0×10-5,1.0×10-5~7.0×10-5,8.0×10-6~5.0×10-5 mol/L;检出限分别为6.0×10-6,4.0×10-6,1.0×10-6 mol/L.  相似文献   

3.
采用荧光光谱法和紫外光谱法, 在模拟生理条件下(pH=7.23)对紫外线吸收剂2-苯基苯并咪唑-5-磺酸(PBSA)与脱氧核糖核酸(DNA)的相互作用进行了研究.结果表明PBSA能够与DNA相结合形成复合物,引起了PBSA紫外吸收的降低和荧光的猝灭;PBSA与DNA的相互作用为静态猝灭过程,两者间的结合位点数为1.11.  相似文献   

4.
采用荧光光谱法和热力学理论,考察了中性红(NR)与鲱鱼精脱氧核糖核酸(DNA)作用的结合模式及作用力.实验结果证明NR与DNA相互作用方式为嵌插模式,作用力以静电结合为主.  相似文献   

5.
熊大珍 《科技信息》2010,(23):I0050-I0051
在25°C,37°C和42°C测定了脱氧核糖核酸(DNA)对血卟啉(HP)的荧光猝灭光谱,研究了在模拟人体生理条件下,血卟啉(HP)与脱氧核糖核酸(DNA)结合反应的特征,计算了荧光猝灭常数和热力学参数。结果表明,随着DNA浓度的增加,HP-Zn的荧光猝灭越来越严重,通过可计算表明脱氧核糖核酸(DNA)与血卟啉(HP)的猝灭常数较大,说明脱氧核糖核酸(DNA)与血卟啉(HP)的结合作用较强,为血卟啉用于临床提供了理论依据。  相似文献   

6.
以邻硝基苯酚、邻氨基苯酚、甘油为原料,在浓硫酸催化下,用Skraup法合成了8-羟基喹啉;实验结果表明,其最佳反应条件为:邻硝基苯酚与邻氨基苯酚物质量的比为1∶2,反应温度为130℃,反应时间为2.5 h;用8-羟基喹啉荧光分光光度法测定油炸食品中铝的含量,为食品加工和安全检测提供了重要参考。  相似文献   

7.
研究了硝基苯及其主要降解中间产物邻硝基苯酚、间硝基苯酚和对硝基苯酚对明亮发光杆菌的单一毒性及多元混合联合毒性的影响.采用毒性单位法(TU)、加和指数法(AI)以及混合毒性指数法(MTI)进行了评价.实验结果表明,硝基苯、邻硝基苯酚、间硝基苯酚和对硝基苯酚半致死浓度的-log EC50值分别为3.21、3.40、3.30和4.15.这4种有机物二元、三元和四元混合溶液的生物毒性主要表现为部分相加或协同作用.  相似文献   

8.
采用荧光光谱法研究了FPZ与DNA的相互作用机理.实验结果表明,DNA通过静态猝灭机制使FPZ的荧光发生猝灭,疏水作用力和氢键在FPZ-DNA复合物形成过程中发挥主要作用,FPZ和DNA的相互作用模式是嵌插结合方式.  相似文献   

9.
用荧光光谱法、紫外-可见分光光度法在生理条件下(pH-7.41)研究了β-环糊精(β-CD)、6-去氧-(N-胺乙基)环糊精(CR—β—CDen)分别与刚果红(CR)的包合作用;研究了CR,(CR—β—CD)和(CR—p—CDen)超分子体系与小牛胸腺DNA的相互作用。紫外滴定实验结果表明:(1)β-环糊精和6-去氧-(N-胺乙基)环糊精都与客体分子刚果红发生超分子作用;(2)CR,CR—pCD,CR-β-CDen与小牛胸腺DNA作用的结合常数Kb值分别为4.1×10^4L/mol,1.36×10^5L/mol,2.33×10^5L/mol,表明超分子体系CR-β-CDen与DNA的相互作用最强。荧光实验结果表明三种化合物CR,CR—β—CD,CR-β-CDen的荧光强度随着CT—DNA的增加而增大,其中环糊精衍生物CR—β—CDen荧光增强效果是最好的。  相似文献   

10.
研究了脱氧核糖核酸(DNA)与Tb^3+的相互作用.发现DNA能增敏Tb^3+的特征荧光.且热变性DNA对Tb^3+的荧光增敏作用比DNA强几十倍.基于上述实验现象,探讨了四种核苷酸d—AMP.d—CMP.d—GMP,d-TTP及四种核苷dA、dC、dG、dT与Tb^3+相互作用的荧光光谱.发现DNA对Tb^3+的荧光增敏除与鸟嘌呤碱基有关外,还有可能与磷酸基有关.进一步选择了含有不同数目磷酸基的核苷酸GMP、GDP、GTP及dG研究磷酸基的作用.实验结果表明不含磷酸基的dG不增敏Tb^3+的荧光,而分别含有1、2、3个磷酸基的GMP、GDP、GTP三种核苷酸对Tb^3+的荧光增敏程度依次为GTP〉GDP〉GMP.认为DNA对Th^3+的荧光增敏是鸟嘌呤碱基和磷酸基共同作用的结果.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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-  相似文献   

18.
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-  相似文献   

19.
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  相似文献   

20.
<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  相似文献   

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