Nucleic Acid Driven DNA Machineries Synthesizing Mg2+‐Dependent DNAzymes: An Interplay between DNA Sensing and Logic‐Gate Operations

Polymerase/nicking enzymes and nucleic‐acid scaffolds are implemented as DNA machines for the development of amplified DNA‐detection schemes, and for the design of logic gates. The analyte nucleic acid target acts, also, as input for the logic gates. In the presence of two DNA targets, acting as inputs, and appropriate DNA scaffolds, the polymerase‐induced replication of the scaffolds, followed by the nicking of the replication products, are activated, leading to the autonomous synthesis of the Mg²⁺‐dependent DNAzyme or the Mg²⁺‐dependent DNAzyme subunits. These biocatalysts cleave a fluorophore/quencher‐functionalized nucleic‐acid substrate, thus providing fluorescence signals for the sensing events or outputs for the logic gates. The systems are used to develop OR, AND, and Controlled‐AND gates, and the DNA‐analyte targets represent two nucleic acid sequences of the smallpox viral genome.     

离子液体中脂肪酶催化酯类合成的新进展

作为21世纪最具发展潜力的绿色溶剂,离子液体用于酶促合成的反应介质具有得天独厚的优势.与传统的有机溶剂相比,离子液体能够提高脂肪酶的稳定性和选择性,减少有机合成中的副反应和有毒气体的产生,后处理简单,可重复利用.参考10年来的文献,从脂肪酶催化酯类合成的常用离子液体种类、过程因素及场/反应器强化等方面进行了综述,同时展望了离子液体在未来酯类酶促合成领域的发展趋势.     

Improvement on mixed-potential type ammonia sensor by a Cr2O3 gas-phase catalyst layer

Journal of Solid State Electrochemistry - Mixed-potential type ammonia sensors based on yttria-stabilized zirconia are promising devices in NOx reducing system for high-temperature exhaust....