Axis-switch method

Applying short ssDNA strands that selectively interact with a specific part of a molecular device is another method to make the device move. A robust rotary device was developed based on multiple crossover motifs [91]. The motivity of the device was the reversible binding of DNA strands. The central axis consists of a couple of ssDNA sections. The conformation of the two ssDNA strands can readily be switched between a PX conformation and its topoisomer conformation. The ssDNA strand replacement can cause the interconversion between the two conformations, and results in an 180° rotation of the end of one strand. This work showed that a rotary nanomechanical device is capable of being cycled by the addition of strands that direct its structure (Fig. 12a). As an application of the DNA nanodevice, a unique DNA nanomechanical device that enables the positional synthesis of products whose sequences are determined by the state of the device has been... 

All diffraction-unlimited nanoscopy methods can provide improved axial resolution even when implemented with a single lens [77,83,120,131,132[. However, because it starts out from less favorable values, the -resolution usually remains worse than its focal plane counterpart. The coherent use of opposing lenses pioneered in 4Pi microscopy and FM, however, facilitates an independent resolution improvement factor by 3-7-fold along the optic axis as has already been demonstrated with STED [83,84,87]. In the stochastic single molecule switching modalities, a similar gain in resolution will take place by the coherent use of opposing lenses [133]. Thus, while 4Pi microscopy and FM did not break the diffraction barrier, they remain cornerstones of far-field fluorescence nanoscopy in the future. 

Flow Rate Measurements, Methods, Figure 13 Response of flow sensor at very low flow rates, (a) Instantaneous current values when the flow was varied and switched. The results in (a) are replotted in (b). The velocities of beads at different flow rates of the fluid are also shown on the right axis of (a). (The peaks in (b) correspond to the flow rate values labeled) [6]... 

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