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941.
Liang-Liang Wang Qiu-Long Zhang Yang Wang Yan Liu Jiao Lin Fan Xie Liang Xu 《Chemical science》2021,12(25):8698
Introduction of artificial metal–ligand base pairs can enrich the structural diversity and functional controllability of nucleic acids. In this work, we revealed a novel approach by placing a ligand-type nucleoside as an independent toehold to control DNA strand-displacement reactions based on metal–ligand complexation. This metal-mediated artificial base pair could initiate strand invasion similar to the natural toehold DNA, but exhibited flexible controllability to manipulate the dynamics of strand displacement that was only governed by its intrinsic coordination properties. External factors that influence the intrinsic properties of metal–ligand complexation, including metal species, metal concentrations and pH conditions, could be utilized to regulate the strand dynamics. Reversible control of DNA strand-displacement reactions was also achieved through combination of the metal-mediated artificial base pair with the conventional toehold-mediated strand exchange by cyclical treatments of the metal ion and the chelating reagent. Unlike previous studies of embedded metal-mediated base pairs within natural base pairs, this metal–ligand complexation is not integrated into the nucleic acid structure, but functions as an independent toehold to regulate strand displacement, which would open a new door for the development of versatile dynamic DNA nanotechnologies.This metal-mediated artificial base pair can function as an independent toehold based on metal–ligand coordination and exhibit flexible and reversible controllability to manipulate the dynamics of strand displacement. 相似文献
942.
Enzyme-catalyzed reaction of o-phenylenediamine (OPD)-Hz02-horseradish peroxidase (HRP) voltammetric enzyme-linked immunoassay system has been studied in detail with electrochemical
analysis, high performance liquid chromatography (HPLC), ultraviolet/visible (UV/Vis) spectroscopy, infrared (IR) spectroscopy
and nuclear magnetic resonance (NMR) spectroscopy. The pure product of H202 oxidizing OPD catalyzed by HRP was prepared with chemical method. The experimental results of voltammetry and HPLC indicate
that only one product of enzyme-catalyzed reaction has been obtained under the selected enzyme-catalyzed reaction conditions.
Identifications by UV/ Vis spectrum, IR spectrum and13C NMR spectrum show that the product is 2,3-diaminophenazine. The processes of the enzyme-catalyzed reaction and the electroreduction
of the product of the enzyme-catalyzed reaction are described.
Project supported by the National Natural Science Foundation of China 相似文献
943.
Type 2 diabetes mellitus (T2DM) is a noteworthy worldwide public health problem. It represents a complex metabolic disorder, mainly characterized as hyperglycemia and lipid dysfunction. The gut microbiota dysbiosis has been proposed to play a role in the development of diabetes. Recently, there has been considerable interest in the use of medicine food homology (MFH) and functional food herbs (FF) to ameliorate diabetes and lead to a natural and healthy life. Hence, this review compiles some reports and findings to demonstrate that the practical use of the MFH/FF can modulate the homoeostasis of gut microbiota, thereby ameliorating the development of T2DM. The results provided useful data to support further investigation of the functional basis and application of MFH/FF to treat T2DM through maintaining intestinal homeostasis. 相似文献
944.
945.
Armin de Meijere Vladimir Chaplinski Harald Winsel Mikhael A. Kusnetsov Paul Rademacher Roland Boese Thomas Haumann Marit Traetteberg Paul von R. Schleyer Tosja Zywietz Haijun Jiao Pascal Merstetter Fabian Gerson 《Angewandte Chemie (International ed. in English)》1999,38(16):2430-2433
A surprisingly high first vertical ionization energy (8.44 eV) and an unusually high oxidation potential are exibited by tricyclopropylamine ( 1 )—in sharp contrast to triisopropylamine. These are attributed to the near-tetrahedral geometry of 1 at the N atom and the perpendicular orientation—with respect to the N-orbital axis—of the cyclopropyl groups. γ-Irradiation of 1 led to the radical cation 1 .+, which, in accord with computations, has a planar C3h-symmetrical structure. The EPR-spectroscopic and computational results disclose a dramatic, previously not reported, conformational change on going from 1 to 1 .+. 相似文献
946.
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948.
949.
HP-β-CD手性流动相HPLC法拆分萘普生对映体的色谱保留机制和拆分机理研究 总被引:6,自引:0,他引:6
研究了HPLC法羟丙基_β_环糊精(HP_β_CD)手性流动相添加剂对萘普生对映体的保留机制,建立了保留因子与[CD]、[H ]、包结常数以及萘普生的解离常数的关系式,并结合实验对此关系式进行了验证,结果表明此关系式对手性添加剂、pH等因素对拆分的影响具有一定的理论指导。保留因子(k)的倒数1k对HP_β_CD的浓度呈良好的线性关系,证明HP_β_CD与萘普生对映体形成的包合比是11包合物。计算了手性分离过程中的热力学参数,结果表明HP_β_CD对萘普生对映体的分离过程主要是一个焓驱动的过程,包合过程是一个放热过程。通过比较手性选择体结构,探讨了HP_β_CD拆分萘普生对映体的机理,进一步分析表明HP_β_CD能拆分萘普生对映体的主要因素是尺寸大小相匹配、构象诱导作用和偶极_偶极作用。 相似文献
950.
Di Peng Xu Liu Lingrui Jiao Ziyan Li Xin Wen Chaokai Yuan Guilai Han Yunfeng Liu Yingzheng Liu Zonglin Jiang 《Acta Mechanica Sinica》2021,(1):20-26
The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings.We proposed a s... 相似文献