DEVELOPMENT OF A GENERIC ULTRASOUND VIBRO-ACOUSTIC IMAGING PLATFORM FOR TISSUE ELASTICITY AND VISCOSITY

Tissue elasticity and viscosity are always associated with pathological changes.As a new imaging method,ultrasound vibro-acoustic imaging is developed for quantitatively measuring tissue elasticity and viscosity which have important significance in early diagnosis of cancer.This paper developed an ultrasound vibro-acoustic imaging research platform mainly consisting of excitation part and detection part.The excitation transducer was focused at one location within the medium to generate harmonic vibration and shear wave propagation,and the detection transducer was applied to detect shear wave at other locations along shear wave propagation path using pulse-echo method.The received echoes were amplified,filtered,digitized and then processed by Kalman filter to estimate the vibration phase.According to the phase changes between different propagation locations,we estimated the shear wave speed,and then used it to calculate the tissue elasticity and viscosity.Preliminary phantom experiments based on this platform show results of phantom elasticity and viscosity close to literature values.Upcoming experiments are now in progress to obtain quantitative elasticity and viscosity in vitro tissue.

IMPACT OF DYNAMICAL HYDRATION SHELL AROUND HA PROTEIN ON NONLINEAR CONCENTRATION DEPENDENT T-RAYS ABSORPTION

T rays is sensitive to covalently cross linked proteins and can be used to probe unique dynamic properties of water surrounding a protein.In this paper,we demonstrate the unique abeorption properties of the dynamic hydnation shells deternined by hemagglutinin(HA)protein in ter-ahertz frequency.We study the changes arising fom diferent concentrations in detail and show that nonlinear absorption coefficient is induced by the dynamic hydration water.The binary and ternary component model were used to interpret the nonlinearity absorption behaviors and predict the thickness of the hydration shells around the HA protein in aquous phase.

NEW FOCUSED ULTRASOUND TRANSDUCER FOR FAT CELL DISRUPTION

Being an emerging body-shaping technology of fat cell disruption,high-intensity focused ultrasound has been investigated intensively in recent years for its favorable natures such as painlessness,safety and noninvasion.One of the major problems for the technology,however,is the overheating of transducers.In this study,we modified the transducer design in order to solve the overheating problem.We simulated the performance of the modified design by finite element analysis and fabricated the newly designed transducer.By measuring the actual performance data,we proved that the new design can effectively reduce temperature rise while keeping the acoustic intensity field unaffected.

Rice stripe mosaic virus hijacks rice heading‐related gene to promote the overwintering of its insect vector

Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of China.It is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice fields.Our field investigations revealed that RSMV infection causes delayed rice heading,resulting in a large number of green diseased plants remaining in winter rice fields.This creates a favorable environment for leafhoppers and viruses to overwinter,potentially contributing to the rapid spread and epidemic of the disease.Next,we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant.A rice heading‐related E3 ubiquitin ligase,Heading date Associated Factor 1(HAF1),was found to be hijacked by the RSMV‐encoded P6.The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins,HEADING DATE 1 and EARLY FLOWERING3,leading to a delay in rice heading.Our results provide new insights into the development regulation‐based molecular interactions between virus and plant,and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.