We report that small, single-stranded circular DNA oligonucleotides 26 to 74 nucleotides (nt) in size can behave as catalytic templates for DNA synthesis by several DNA polymerase enzymes. The DNA products are repeating end-to-end multimeric copies of the synthetic circular DNAs, and range from 1 000 to > 12 000 nucleotides in length. Several aspects of this reaction are unusual: first, the synthesis proceeds efficiently despite the curvature and small size of the circles, some of which have diameters significantly smaller than that of the enzyme itself. Second, the synthesis can proceed hundreds of times around the circle, while rolling replication of larger circular plasmid DNAs requires other proteins for processive synthesis. Finally, the synthesis scheme produces multiple copies of the template without the requirement for either heating or cooling cycles and requires less than stoichiometric amounts of primer, unlike other DNA synthesis methods. We report on the scope of this reaction, and demonstrate that the multimeric products can be cleaved enzymatically to short, sequence-defined oligodeoxynucleotides. This new approach to DNA synthesis may be a practical way to produce useful repeating DNAs, and combined with DNA cleavage strategies, it may represent a useful enzymatic approach to short, sequence-defined oligodeoxynucleotides.

Developing robust electrocatalysts and advanced devices is important for electrochemical carbon dioxide (CO2) reduction toward the generation of valuable chemicals. We present herein a carbon‐confined indium oxide electrocatalyst for stable and efficient CO2 reduction. The reductive corrosion of oxidative indium to the metallic state during electrolysis could be prevented by carbon protection, and the applied carbon layer also optimizes the reaction intermediate adsorption, which enables both high selectivity and activity for CO2 reduction. In a liquid‐phase flow cell, the formate selectivity exceeds 90 % in a wide potential window from −0.8 V to −1.3 V vs. RHE. The continuous production of ca. 0.12 M pure formic acid solution is further demonstrated at a current density of 30 mA cm−2 in a solid‐state electrolyte mediated reactor. This work provides significant concepts in the parallel development of electrocatalysts and devices for carbon‐neutral technologies.

The problem of formulating solutions immediately and comparing them rapidly for billboard placements has plagued advertising planners for a long time, owing to the lack of efficient tools for in-depth analyses to make informed decisions. In this study, we attempt to employ visual analytics that combines the state-of-the-art mining and visualization techniques to tackle this problem using large-scale GPS trajectory data. In particular, we present SmartAdP, an interactive visual analytics system that deals with the two major challenges including finding good solutions in a huge solution space and comparing the solutions in a visual and intuitive manner. An interactive framework that integrates a novel visualization-driven data mining model enables advertising planners to effectively and efficiently formulate good candidate solutions. In addition, we propose a set of coupled visualizations: a solution view with metaphor-based glyphs to visualize the correlation between different solutions; a location view to display billboard locations in a compact manner; and a ranking view to present multi-typed rankings of the solutions. This system has been demonstrated using case studies with a real-world dataset and domain-expert interviews. Our approach can be adapted for other location selection problems such as selecting locations of retail stores or restaurants using trajectory data.