DNA branched junctions have been constructed that contain either five arms or six arms surrounding a branch point. These junctions are not as stable as junctions containing three or four arms; unlike the smaller junctions, they cannot be shown to migrate as a single band on native gels when each of their arms contains eight nucleotide pairs. However, they can be stabilized if their arms contain 16 nucleotide pairs. Ferguson analysis of these junctions in combination with three-arm and four-arm junctions indicates a linear increase in friction constant as the number of arms increases, with the four-arm junction migrating anomalously. The five-arm junction does not appear to have any unusual stacking structure, and all strands show similar responses to hydroxyl radical autofootprinting analysis. By contrast, one strand of the six-arm junction shows virtually no protection from hydroxyl radicals, suggesting that it is the helical strand of a preferred stacking domain. Both junctions are susceptible to digestion by T4 endonuclease VII, which resolves Holliday junctions. However, the putative helical strand of the six-arm junction shows markedly reduced cleavage, supporting the notion that its structure is largely found in a helical conformation. Branched DNA molecules can be assembled into structures whose helix axes form multiply connected objects and networks. The ability to construct five-arm and six-arm junctions vastly increases the number of structures and networks that can be built from branched DNA components. Icosahedral deltahedra and 11 networks with 432 symmetry, constructed from Platonic and Archimedean solids, are among the structures whose construction is feasible, now that these junctions can be made.

Recently, we have invested a great deal of effort to construct molecular building blocks from unusual DNA motifs. DNA is an extremely favorable construction medium. The sticky-ended association of DNA molecules occurs with high specificity, and it results in the formation of B-DNA, whose structure is well known. The use of stable-branched DNA molecules permits one to make stick-figures. We have used this strategy to construct a covalently closed DNA molecule whose helix axes have the connectivity of a cube, and a second molecule, whose helix axes have the connectivity of a truncated octahedron. In addition to branching topology, DNA also yields control of linking topology, because double helical half-turns of B-DNA or Z-DNA can be equated, respectively, with negative or positive crossings in topological objects. Consequently, we have been able to use DNA to make trefoil knots of both signs and figure of 8 knots. By making RNA knots, we have discovered the existence of an RNA topoisomerase. DNA-based topological control has also led to the construction of Borromean rings, which could be used in DNA-based computing applications. The key feature previously lacking in DNA construction has been a rigid molecule. We have discovered that DNA double crossover molecules can provide this capability. We have incorporated these components in DNA assemblies that use this rigidity to achieve control on the geometrical level, as well as on the topological level. Some of these involve double crossover molecules, and others involve double crossovers associated with geometrical figures, such as triangles and deltahedra.

populations. Moreover, with the advent of the novel coronavirus disease (COVID-19), significant investment in medical resources is required. Under the umbrella of the global COVID-19 pandemic, the use of biosensors in healthcare and online medical care are becoming ubiquitous, which represent methods that can be used to detect signs from the human body for further health analysis. Furthermore, the internet of things (IoT) technology in healthcare is a method by which biosensorembedded objects can be worn on the human body in everyday life that continuously measure and digitize health information without any burden to the wearer. [1] Recently, various biometric technologies have been developed, wearable devices such as smart watches, invasive biodevices, and devices that sense the everyday surrounding environment of the wearer. Medical data can be collected using such devices, which can then be further analyzed by artificial intelligence (AI). These data can then be used for health promotion, prevention of disease, and early disease diagnosis. Moreover, with the advent of COVID-19, healthcare IoT (HIoT) technology has become extremely important. [2] In terms of the individual, when a mask is constantly worn it may cause lung damage to the user. Therefore, the HIoT would make a significant contribution in this case to offer forewarning about the situations of the lungs As society advances, the shift from passive medical care to health management and preventive medical care has become an important issue, with the realization of wearable monitors becoming desirable. In light of the COVID-19 pandemic, the number of patients who are in urgent need of the monitoring of biological information is increasing. This review focuses on piezoelectric materials and composites that convert kinetic energy into electrical energy to realize self-powered wearable monitoring sensors, outlining the recent research activity on sensors for use in healthcare monitoring. First, a general description of the principles of piezoelectric monitoring sensors is given. Next, the development status of piezoelectric materials and composites aimed at the application of detecting tiny motions of the human body is introduced, and then the research trends on the detection of larger human body movements are highlighted. Finally, after presenting the performance of current piezoelectric sensors and future research guidelines for developing multifunctional systems in the post COVID-19 era, the achievements are summarized. Overall, this review will provide guidance to researchers who are seeking to design and develop highly sensitive self-powered piezoelectric sensors that monitor human motion and physiological signals.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/admt.202200318.

We describe a new way of understanding enhanced molecular recognition through substrate–additive complex formation and the development of the first catalytic kinetic resolution of α-hydroxythioamides, which are versatile synthetic building blocks, using chiral N-heterocyclic carbene-catalyzed enantioselective acylation assisted by a carboxylate additive. Mass spectrometry provided evidence for the role of the additive, which forms a hydrogen-bonded complex with α-hydroxythioamide, resulting in both rate and selectivity enhancements. The synthetic applications of the resolved α-hydroxythioamides highlight the usefulness of the developed method.