排序方式: 共有25条查询结果,搜索用时 31 毫秒
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Vardevanyan PO Antonyan AP Parsadanyan MA Davtyan HG Karapetyan AT 《Experimental & molecular medicine》2003,35(6):527-533
The pH-induced helix-coil transition of DNA and its complexes with EtBr is carried out at acidic pH in a wide interval of change of concentration ratio of EtBr/DNA. The binding isotherms of EtBr on double and single-stranded DNA at pH = 7.0 and pH = 3.0 (t = 25(o)C) are obtained by absorption and fluorimetric methods. Binding constants (K) and number of bases (n), corresponding to one binding site were determined. Non fluorescent "strong" complex with ds-DNA at pH = 7.0 and t = 25(o)C as well as "strong" and "weak" complexes with ss-DNA at pH = 3.0 and t = 25(o)C are revealed. 相似文献
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Minasyan SH Tavadyan LA Antonyan AP Davtyan HG Parsadanyan MA Vardevanyan PO 《Bioelectrochemistry (Amsterdam, Netherlands)》2006,68(1):48-55
The interaction of ethidium bromide (EtBr) with calf thymus DNA is investigated electrochemically with the use of differential pulse voltammetry (DPV) at two different ionic strengths of a solution (0.154 M and 0.02 M [Na+], pH 7.0). It is revealed that EtBr binds with DNA in more than one way. The appropriate values of constants (K) and number site sizes (n) of EtBr binding to DNA are determined. The values of binding constants are equal to 1.9 x 10(6) and 5.6 x 10(5) M(-1), and number site sizes to 9 and 3.6 for strong interactions at ionic strengths of solutions 0.02 and 0.154 M Na+ at 28 degrees C, respectively. For a weaker interaction, these parameters are equal to 7 x 10(4) and 8 x 10(4) M(-1) and 1.5 and 1 at the mentioned ionic strengths of solutions, respectively. Thus, EtBr interacts with DNA in more than one way--intercalative and electrostatic at low ionic strength, and semi-intercalative and electrostatic at a higher strength of the solution. These results are in good accordance with the ones obtained by spectroscopic (absorption and fluorimetric) methods. 相似文献
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非线性涡黏性系数模型和代数应力模型联系了线性涡黏性系数湍流模型和完整的微分
雷诺应力模型.随着它们受到日益关注,其形式也越来越多样化.本篇综述的目的是对这些模
型加以总结并比较它们之间的共同点及不同之处,指出它们与完整微分雷诺应力模型之间的
关系,以及相对于线性涡黏性系数模型而言它们在预报流场上所具有的优势. 相似文献
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K. Yu. Amirbekyan A. P. Antonyan P. O. Vardevanyan Sh. A. Markarian 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(12):2027-2029
Interaction between benzimide (Hoechst 33258, H33258) and calf thymus DNA in aqueous dimethyl sulfoxide is investigated by means of UV-Vis and fluorescence spectroscopy at a constant ratio (r) of the number of H33258 molecules and DNA base pairs. Melting curves of the DNA-H33258 complex are obtained from the temperature dependences of the normalized optical density and fluorescence intensity, and the melting temperatures of the complex are determined. It is shown that adding dimethyl sulfoxide (DMSO) lowers the complex’s melting temperature. It is concluded that a long wavelength shift of the fluorescence spectra occurs when the temperature is raised. 相似文献
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We present a computer model of diffusion limited aggregation with linear seed. The clusters with varying linear seed lengths are simulated, and their pattern structure, fractal dimension and multifractal spectrum are obtained. The simulation results show that the linear seed length has little effect on the pattern structure of the aggregation clusters if its length is comparatively shorter. With its increasing, the linear seed length has stronger effects on the pattern structure, while the dimension D f decreases. When the linear seed length is larger, the corresponding pattern structure is cross alike. The larger the linear seed length is, the more obvious the cross-like structure with more particles clustering at the two ends of the linear seed and along the vertical direction to the centre of the linear seed. Furthermore, the multifractal spectra curve becomes lower and the range of singularity narrower. The longer the length of a linear seed is, the less irregular and nonuniform the pattern becomes. 相似文献