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21.
A magnetically assisted fluorescence ratiometric technique has been developed for adenosine deaminase assays with high sensitivity
using water-soluble cationic conjugated polymers (CCPs). The assay contains three elements: a biotin-labeled aptamer of adenosine
(biotin-aptamer), a signaling probe single-stranded DNA-tagged fluorescein at terminus (ssDNA-Fl) and a CCP. The specific
binding of adenosine to biotin-aptamer makes biotin-aptamer and ssDNA-Fl unhybridized, and the ssDNA-Fl is washed out after
streptavidin-coated magnetic beads are added and separated from the assay solution under magnetic field. In this case, after
the addition of CCP to the magnetic beads solution, the fluorescence resonance energy transfer (FRET) from CCP to fluorescein
is inefficient. Upon adding adenosine deaminase, the adenosine is converted into inosine, and the biotin-aptamer is hybridized
with ssDNA-Fl to form doubled stranded DNA (biotin-dsDNA-Fl). The ssDNA-Fl is attached to the magnetic beads at the separation
step, and the addition of CCP to the magnetic beads solution leads to efficient FRET from CCP to fluorescein. Thus the adenosine
deaminase activity can be monitored by fluorescence spectra in view of the intensity decrease of CCP emission or the increase
of fluorescein emission in aqueous solutions. The assay integrates surface-functionalized magnetic particles with significant
amplification of detection signal of water-soluble cationic conjugated polymers.
Supported by the “100 Talents” Program of the Chinese Academy of Sciences, and the National Natural Science Foundation of
China (Grant No. 20574073) 相似文献
22.
超快速冷却工艺对中低碳钢组织性能的影响 总被引:1,自引:0,他引:1
基于UFC-ACC设计理念,结合超快速冷却机理及其在中厚板产品处理过程中的技术实现,针对中低碳钢采用不同轧制方式,分析超快冷后钢板力学性能变化,得出较优超快冷冷却规程;同时,对比不同工艺条件下的金相组织,结合理论计算,总结出超快速冷却条件下中低碳钢组织性能演变规律.从分析结果看,中低碳钢冲击韧性明显提高,其他力学性能也有较大改善;此外,UFC-ACC冷后机体大部分为细小均匀的F+P组织,并能保持原奥氏体中的高密度位错,使钢板性能优于普通ACC处理后钢板. 相似文献
23.
应用PCR从杜仲内生Pseudomonas koreensis JDM-2株基因组中扩增出ACC脱氨酶基因acdS,将其克隆到pMD18-T载体并段进行DNA测序,通过BamHⅠ和HindⅢ酶切从重组质粒pMD18ACDS中切下acdS基因序列,将其连接到pQE30质粒的BamHⅠ和HindⅢ位点,构建表达质粒pQE30ACDS,转化大肠杆菌BL21,利用比色法测定ACC脱氨酶活力.测序结果表明,JDM-2菌株acdS基因大小为1 017 bp,与已报道不同菌种acdS基因的同源性在86%~99%之间.SDS-PAGE结果显示在大肠杆菌BL21中表达了分子量为38 kDa的ACC脱氨酶.酶活性检测结果显示重组菌ACC脱氨酶的酶活力为0.214 U/mg. 相似文献
24.
具有ACC脱氨酶活性及抗枯萎病菌的假单胞菌株B*8 总被引:7,自引:1,他引:6
运用新的快速筛选程序,获得了具有1-氨基环丙烷-1-羧酸(1-aminocyclopropane-1car-boxylate,ACC)脱氨酶活性和拮抗瓜类枯萎病菌双重功能的根际假单胞菌株B8.利用ACC为唯一氮源,从不同的土样中,快速筛选出80个具有ACC脱氨酶活性的菌落.在马铃薯葡萄糖培养基和西瓜培养基上,经异步培养法进一步筛选并纯化出3株对西瓜枯萎病菌具有较强拮抗作用的拮抗菌A9、B8和C17.对拮抗作用最强的B8进行分析表明,它属于假单孢菌属,能分泌较多的铁载体,对瓜类枯萎病以及其他植物病原菌具有广谱抗性.结果显示,此程序可替代通常采用的低效而耗时的筛选和生物测定过程,加快新的促进植物生长根际细菌的筛选和应用. 相似文献
25.
26.
大脑前额叶扣带回皮层是一个与感觉功能密切相关的脑区,它能够对丘脑触觉反应进行调制.实验在10只戊巴比妥钠(1%)麻醉的SD雄性大鼠上进行,采用辣根过氧化物酶(horseradish peroxidase,HRP)逆行标记的方法,对扣带皮层前部调制丘脑腹侧基底核(ventrobasal,VB)感觉信息的途径进行了研究.实验结果显示,VB核可以接受扣带皮层后部的投射,而且扣带皮层前部有纤维投射到扣带皮层后部.由此提示了前扣带皮层对丘脑腹侧基底核神经元触觉信息调制的可能神经环路是:扣带皮层前部-扣带皮层后部-丘脑腹侧基底核. 相似文献
27.
Vallur AC Yabuki M Larson ED Maizels N 《Cellular and molecular life sciences : CMLS》2007,64(5):555-565
Expressed immunoglobulin (Ig) genes undergo alterations in sequence and genomic structure in order to optimize antibody function. A single B cell-specific factor, activation-induced deaminase (AID), initiates these changes by deamination of cytosine to uracil. Uracil in DNA is encountered commonly, and conserved pathways are responsible for its faithful repair. However, at the Ig loci of B cells, AID-initiated damage is processed to produce three distinct outcomes: somatic hypermutation, class switch recombination and gene conversion. This review focuses on the role of AID in Ig gene diversification, emphasizing how AID functions within the mechanism of the Ig gene diversification pathway; and highlights open questions for future research, particularly the most provocative current question: what makes a gene a target for AID-initiated mutagenesis? 相似文献
28.
介绍了开发DMIS中ACC车次输入(自动和半自动)的界面,讨论了网络套接口的数据通信机制在本应用程序中的具体实现,还介绍了开发过程中的难点及其解决办法. 相似文献
29.
Bonanzinga给出的两个例子表明一个ACC空间的完备象不一定是ACC,一个ACC空间的完备前象不一定是ACC.在这个注记中,我们按通常的方法给出两个例子,它们比Bonanzinga的例子简单了许多. 相似文献
30.
价值工程理论源于制造业,目前在很多行业得到了广泛的应用,但是在国内招标中应用较少。本文以某电力建设项目空冷岛招标为例,对应用价值工程理论招标进行了介绍,希望价值工程理论能够在招标中得到更多的应用。 相似文献