A Molecular Circuit Regenerator to Implement Iterative Strand Displacement Operations.

The predictable chemistry of Watson-Crick base-pairing imparts a unique structural programmability to DNA, enabling the facile design of molecular reactions that perform computations. However, many of the current architectures limit devices to a single operational cycle. Herein, we introduce the design of the "regenerator", a device based on coupled enthalpic and entropic reactions that permits the regeneration of molecular circuit components.

Accurate quantification of astrocyte and neurotransmitter fluorescence dynamics for single-cell and population-level physiology.

Recent work examining astrocytic physiology centers on fluorescence imaging, due to development of sensitive fluorescent indicators and observation of spatiotemporally complex calcium activity. However, the field remains hindered in characterizing these dynamics, both within single cells and at the population level, because of the insufficiency of current region-of-interest-based approaches to describe activity that is often spatially unfixed, size-varying and propagative. Here we present an analytical framework that releases astrocyte biologists from region-of-interest-based tools. The Astrocyte Quantitative Analysis (AQuA) software takes an event-based perspective to model and accurately quantify complex calcium and neurotransmitter activity in fluorescence imaging datasets. We apply AQuA to a range of ex vivo and in vivo imaging data and use physiologically relevant parameters to comprehensively describe the data. Since AQuA is data-driven and based on machine learning principles, it can be applied across model organisms, fluorescent indicators, experimental modes, and imaging resolutions and speeds, enabling researchers to elucidate fundamental neural physiology.

Exploiting molecular motors as nanomachines: the mechanisms of de novo and re-engineered cytoskeletal motors.

Cytoskeletal molecular motors provide exciting proof that nanoscale transporters can be highly efficient, moving for microns along filamentous tracks by hydrolyzing ATP to fuel nanometer-size steps. For nanotechnology, such conversion of chemical energy into productive work serves as an enticing platform for re-purposing and re-engineering. It also provides a roadmap for successful molecular mechanisms that can be mimicked to create de novo molecular motors for nanotechnology applications. Here we focus specifically on how the mechanisms of molecular motors are being re-engineered for greater control over their transport parameters. We then discuss mechanistic work to create fully synthetic motors de novo and conclude with future directions in creating novel motor systems.