Mechanically manipulating glymphatic transport by ultrasound combined with microbubbles.

The glymphatic system is a perivascular fluid transport system for waste clearance. Glymphatic transport is believed to be driven by the perivascular pumping effect created by the pulsation of the arterial wall caused by the cardiac cycle. Ultrasound sonication of circulating microbubbles (MBs) in the cerebral vasculature induces volumetric expansion and contraction of MBs that push and pull on the vessel wall to generate a MB pumping effect.

Innovative high-gain optically pumped far-infrared laser.

A new optically pumped far-infrared (FIR) laser with separate pump beam reflector and FIR output coupler has been developed. The new design greatly simplifies the tuning of the laser and enables the optimization of the pump beam absorption without affecting the laser alignment. Working with formic acid (HCOOH) vapor pumped by a 30 W CO laser at the 9R20 line, a high laser gain of 3  dB/m and power conversion efficiency of 16.

Far infrared laser polarimetry and far forward scattering diagnostics for the C-2 field reversed configuration plasmas.

A two-chord far infrared (FIR) laser polarimeter for high speed sub-degree Faraday rotation measurements in the C-2 field reversed configuration experiment is described. It is based on high power proprietary FIR lasers with line width of about 330 Hz. The exceptionally low intrinsic instrument phase error is characterized with figures of merit.