Ultrasound therapy has a long history of novel applications in medicine. Compared to high-intensity ultrasound used for tissue heating, low-intensity ultrasound has drawn in-creasing attention recently due to its ability to induce therapeutic changes without biologically significant temperature increase. Low-intensity pulsed ultrasound (LIPUS) is a specific type of ultrasound that delivers at a low intensity and outputs in the mode of pulsed waves. It has minimal thermal effects while maintaining the transmission of acoustic energy to the target tissue, which is able to provide non-invasive physical stimulation for therapeutic applications. LIPUS has been demonstrated to accelerate the healing of fresh fracture, nonunion and delayed union in both animal and clinical studies. The effectiveness of LIPUS for the applications of soft-tissue regeneration and inhibiting inflammatory responses has also been investigated experimentally. Additionally, research has shown that LIPUS is a promising modality for neuromodulation. The purpose of this review is to provide an overview of the recent developments of LIPUS for therapeutic applications, based on the papers that report positive effects, and to present the findings on the understanding of its mechanism. Currently available LIPUS devices are also briefly described in this paper.

We investigate the interaction of visible supercontinuum light with fiber Bragg gratings that are UV-written in a birefringent air-silica microstructure fiber. Spectral enhancements near the grating resonance are observed, and their variations are studied by adjusting the power level and polarization of input pulses. With weak input pulses (<0.5nJ), individual Raman solitons are observed in the spectrum, and the grating generates a picosecond dispersive wave centered near its bandgap when a Raman soliton has both spatial and spectral overlap with the grating resonance. Using the nonlinear Schrödinger equation (NLSE) with a simplified model of the grating dispersion, our numerical modeling reproduces the salient features of this enhancement, and shows the important role played by grating dispersion outside the bandgap.

Triple-modular redundancy (TMR), which consists of three identical modules and a voting circuit, is a common architecture for soft-error tolerance. However, the original TMR suffers from two major drawbacks: the large area overhead and the vulnerability of the voter. In order to overcome these drawbacks, we propose a new complementary dual-modular redundancy (CDMR) scheme for mitigating the effect of soft errors. Inspired by the Markov random field (MRF) theory, a two-stage voting system is implemented in CDMR, including a first-stage optimal MRF structure and a second-stage high-performance merging unit. The CDMR scheme can reduce the voting circuit area by 20% while saving the area of one redundant module, achieving at least 26% error-rate reduction at an ultralow supply voltage of 0.25 V with 8.33% faster timing compared to previous voter designs.

Subwavelength freestanding InGaN/GaN quantum well microtubes with a wall thickness of about 50 nm are formed by selective release of a coherently strained bilayer heterostructure from a hosting substrate. Highly polarized spontaneous and stimulated emissions due to whispering gallery mode oscillation were observed in photoluminescence spectra at room temperature. The quality factor was increased by a factor of 3 by elevating the microtube from the substrate and reducing light leakage before threshold. A lasing threshold was characterized as low as 3 mJ/cm². Microtubes were immersed in different liquids with refractive index variation as small as 0.01 and tested below and above threshold. The peak positions shift obviously while exhibiting excellent repeatability. Using a simple optical probe-detect method, a 5-μm diameter microtube cavity achieves a sensitivity of 40 nm/refractive index unit (RIU) and a detection limit of 6 × 10⁻³ RIU.

Reliability is one of the major concerns for ultralow power circuit designs. Markov random field (MRF) techniques have been applied to logic circuits to resist random noise when operating under ultralow supply voltage or sub-threshold voltage. Although conventional MRF networks can be easily mapped onto simple logic circuits, it becomes difficult when the circuits are large and complex. In this paper, we present a general coding-based partial MRF (CPMRF) method for multi-logic operations in one basic unit, which is referred to as a CPMRF pair. A CPMRF pair saves circuit area by sharing a common MRF network. It also inherits noise immunity from the MRF theory while obtaining noise immunity from the coding structure as a combination of robust ``1s'' and ``0s.'' The resulting architectures become more cost effective than conventional ones. To validate the performance of our proof-of-concept design, we fabricated a carry-lookahead adder implemented by the proposed CPMRF pairs using IBM 130-nm CMOS technology. Measurement results indicate that the CPMRF CLA can achieve high noise tolerance with 20% improvement while occupying 37.7% less area and reducing power consumption by 93% compared with the master-and-slave MRF CLA design.