功能化核酸适体的筛选及分子识别应用

核酸适体是从寡核苷酸文库中筛选获得的一段单链寡核苷酸. 由于能与多种靶标分子高特异性结合, 核酸适体已发展成为一种新兴的分子识别工具, 广泛应用于生物医学等领域. 天然核酸文库有限的化学组成限制了核酸适体的结构和功能, 进而限制了其在分子识别中的应用. 功能化核酸适体通过引入特定的化学官能团使核酸序列具有更丰富的构象和功能, 增强其分子识别能力. 然而, 功能化核酸很难与核酸扩增方法兼容, 因而难以使用传统筛选方法进行功能化核酸的筛选. 因此, 优化筛选方法对于获得具有优异性能的功能化核酸适体至关重要. 本综述总结了功能化核酸适体的筛选方法, 并介绍了其作为分子识别工具在生物医学领域中的应用.     

水杨酸荧光增强法测定酵母核糖核酸

核酸是生物体内重要的生物大分子,定量测定核酸是研究核酸的基础,由于核酸内源荧光很弱,直接利用荧光技术来研究核酸的结构和性质受到限制.     

基于超分子化学的核酸表观遗传修饰研究

核酸是生物体的遗传物质,在生命体系中发挥着重要作用.除了构成核酸的经典碱基之外,核酸中还存在天然修饰的碱基,这被称为核酸的表观遗传修饰.核酸的表观遗传修饰在基因表达过程中具有重要的调控作用,对生物体遗传和生命生长过程影响很大,并且核酸表观遗传与疾病密切相关.超分子化学是研究分子间键的化学,而许多生物分子都需要通过超分子化学作用来发挥其生物功能,可以说生物体内天然存在着大量的超分子化学过程.本文综合评述了基于超分子化学的核酸表观遗传修饰研究的一些代表性工作.     

核酸适体与互补核酸和目标蛋白之间竞争结合的热力学特性研究

以一种基于目标蛋白凝血酶的取代反应来研究核酸适体与互补核酸和核酸适体与目标蛋白之间竞争结合的热力学特性, 研究了核酸适体-互补核酸的解离反应和在目标蛋白存在下取代反应的平衡常数、标准焓变和标准熵变等热力学参数, 结果表明该取代反应是一个熵驱动的自发过程, 熵驱动从双链的核酸转变为核酸适体-目标蛋白的复合物. 该热力学研究会对核酸适体-互补核酸和核酸适体-凝血酶之间的结合过程的机理有一个更深的理解, 将有助于进一步揭示核酸与蛋白这两种生命中最关键物质之间的相互作用和关系, 为更好地理解基本的生物过程和预测设计适体生物传感器, 发展用于疾病诊断的方法有着重要的意义.     

核酸适体偶联药物的生物偶联构建技术与应用

核酸适体被称为“化学抗体”, 具有与抗体类似或更加优异的特异性和亲和力, 可以精准地靶向靶蛋白, 与靶蛋白特异性结合. 此外, 核酸适体还具有获取简单、 合成简便、 易于进行化学修饰、 不易变性、 靶标范围广、 免疫原性低及细胞内化快等优点, 已被广泛应用于众多研究领域. 在癌症治疗领域, 核酸适体作为一种优异的靶向识别工具和药物递送载体, 可实现抗肿瘤药物的精准递送. 将核酸适体与药物分子偶联, 可通过核酸适体的靶向作用使药物分子随核酸适体共同进入靶细胞, 实现药物分子在靶细胞内的富集, 进而促进靶细胞的死亡. 近年来, 核酸适体偶联药物已成为癌症靶向治疗的前沿新兴领域, 希望通过该领域的深入研究为癌症靶向治疗领域提供新思路. 本文综合评述了以生物偶联技术构建的核酸适体偶联药物及其应用研究.     

纳米孔测序技术在核酸修饰检测中的应用

DNA和RNA上广泛存在着多种化学修饰.这些核酸修饰参与基因表达的调控,影响生长发育等生理过程,并可能会引发癌症等疾病.对核酸修饰的精准识别与定位有助于理解其功能机制,帮助相关疾病的诊断与治疗.纳米孔测序是一种新兴的单分子测序技术,可以根据修饰碱基与天然碱基之间阻孔信号的差异实现核酸序列中多种修饰的同时检测,是目前检测核酸修饰最直接的方法.本文简要介绍了纳米孔测序技术的发展和原理以及识别核酸修饰的算法工具,总结了纳米孔测序技术在核酸修饰检测中的应用,并对其发展前景进行了展望.     

框架核酸辅助的仿生膜构建

仿生膜的构建有利于了解并掌握生物膜的功能及其机理, 同时对其在生命医学及疾病诊断等相关领域的应用具有重要意义. 以框架核酸为组装单元, 构建新型仿生膜材料是一种有效且具有发展前景的方法和研究方向. 本文综述了框架核酸的设计、 制备与表征, 总结了框架核酸修饰到脂质膜上的方式. 同时, 对框架核酸辅助的仿生膜的应用情况进行了阐述, 并探讨了框架核酸在仿生膜研究领域所面临的机遇与挑战.     

大环配合物在核酸切割中的应用

核酸切割试剂的研究是化学和分子生物学中最为活跃的前沿领域之一.研究核酸切割试剂,不仅是因为对核酸酶催化机理进行深入了解之需,同时还因为人工核酸酶在基因治疗中有着诱人的前景.大环配合物的合成、结构及其对核酸的切割作用已有广泛的文献报道.本文综述了作为重要的核酸切割试剂的大环多胺配合物和氮杂冠醚配合物对核酸的切割作用及其规律性,并展望了今后的发展与应用方向.     

一种基于RepRap开源3D打印平台的低成本、自动化核酸提取系统

自动化核酸提取技术对于核酸扩增和高通量测序等分子检测应用至关重要.当前,大部分商用自动化核酸提取仪主要以磁分离技术为主,采用高度集成的封闭式结构设计方案,成本高,且不利于在资源有限的环境下使用.此外,核酸样本处理功能模块一旦固定,便很难根据需要对其功能更新和拓展.为了应对上述挑战,该文在基于"快速复制原型机(RepRa...     

基于小分子的核酸结构探针最新研究进展

本文主要综述了基于小分子的核酸结构探针的最新研究进展.所探索的核酸结构主要有四链核酸（包括G-四链体以及i-motif）结构、三链核酸结构、左手螺旋DNA结构以及不规则核酸结构（包括突起结构以及环状结构）等;所探索的小分子包括过渡金属配合物、大环共轭化合物、环肽以及寡糖抗生素等.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

结合实际发展电化学科学─—武汉大学电化学研究室工作简介

结合实际发展电化学科学─—武汉大学电化学研究室工作简介查全性,陆君涛（武汉大学化学系电化学研究室,武汉４３００７２）在物理化学的众多分支学科中,电化学长期保持良好的发展势头。除了电化学所研究的体系（溶液、电极／溶液界面等）具有广泛的基础意义外,促使电...