An analysis on a rigid-flexible coupling system of an oscillating massand a rotating disk

A mass-rod-disk system consisting of an oscillating mass attached to a rigid rotating disk by an elastic rod is designed to study rigid-flexible coupling mechanism.Suppose the rod is lightweight and has enough stiffness,the theorems of linear momentum and angular momentum are applied to the mass-rod-disk system based on the kinematic description of the system.With respect to two deflections of the mass and one angular velocity of the system,a group of nonlinear differential equations are established where the tangential inertial force,centrifugal force,Coriolis force as well as the moments of additional inertial forces take important effects on the dynamic response.For the sake of description,these three types of inertial forces mentioned before are referred to as additional inertial forces in this paper.The horizontal deflections of the mass and the angular velocity of the disk rotating about a fixed-axis are numerically solved for the prescribed external torque.The oscillating trajectory of the mass is deeply influenced by the additional inertial forces,meanwhile the dynamic fluctuations of the angular velocity and rotary inertia of the system are strongly affected by the mass oscillation.

Bioinspired Andrias davidianus-Derived wound dressings for localized drug-elution

Local drug delivery has received increasing attention in recent years.However,the therapeutic efficacy of local delivery of drugs is still limited under certain scenarios,such as in the oral cavity or in wound beds after resection of tumors.In this study,we introduce a bioinspired adhesive hydrogel derived from the skin secretions of Andrias davidianus(SSAD)as a wound dressing for localized drug elution.The hydrogel was loaded with aminoguanidine or doxorubicin,and its controlled drug release and healing-promoting properties were verified in a diabetic rat palatal mucosal defect model and a C57BL/6 mouse melanoma-bearing model,respectively.The results showed that SSAD hydrogels with different pore sizes could release drugs in a controllable manner and accelerate wound healing.Transcriptome analyses of the palatal mucosa suggested that SSAD could significantly upregulate pathways linked to cell adhesion and extracellular matrix deposition and had the ability to recruit keratinocyte stem cells to defect sites.Taken together,these findings indicate that property-controllable SSAD hydrogels could be a promising biofunctional wound dressing for local drug delivery and promotion of wound healing.

Bulk acoustic wave microstreaming trap array for capturing micron particle

The paper proposed a method to capture micron-sized particles in three-dimensional fluid space using bulk acoustic wave(BAW) microstreaming traps.Two types of BAW microstreaming trap arrays were prepared,and the finite element method(FEM) was used to simulate them.The first-order and second-order acoustic fields were obtained by solving the Navier-Stokes equation.The movement of polystyrene particles in the flow field was simulated and analyzed.The experimental results showed that the BAW microstreaming traps could quickly and efficiently capture micron-sized particles in three-dimensional fluid space.The experimental results were in good agreement with the simulation results.Both cylindrical and circular hole BAW microstreaming traps could capture particles in three-dimensional space in tens of seconds.Moreover,the capture efficiency of the cylindrical BAW microstreaming traps was higher than that of circular hole BAW microstreaming traps.This method breaks the limitation that the surface acoustic wave(SAW) microstreaming traps cannot manipulate the particles in three-dimensional space,which improves the efficiency of capturing the particles.