An empirical mode decomposition (EMD)-based time–frequency denoising algorithm is derived in this paper to accomplish the extraction of active ingredients for multi-frequency mixed signals, and then the self-sensing of vibration signals is realized without additional sensors for an ultrasonic-assisted grinding device. EMD is employed to accomplish the signal decomposition, and multiple intrinsic mode function components and the residual are obtained. Then, the weighted factors used for signal reconstruction are obtained based on innovation statistical distance, which is selected as a criterion to evaluate the time–frequency domain correlation between decomposition results and the original signal. Next, the maximum correntropy criterion-based similarity detection method is designed to adaptively modify the weighted factors, and the signal is reconstructed on the foundation of the modified weighted factors. Finally, numerical simulations and a self-sensing experiment are conducted to verify the denoising performance of the proposed algorithm. The self-sensing of the 4.59 dB vibration signal is realized for an ultrasonic-assisted grinding device.

The influence of the ambient pressure on the load capacity of near-field acoustic levitation is studied. Theoretical models based on the acoustic radiation pressure and hydrodynamic lubrication theory are built, taking into account the changes of the ambient pressure. Both simulation and measured results show that the levitation force is positively proportional to the ambient pressure. The levitation force increased by 4–5 times at an ambient pressure of 0.5 MPa. A maximum load capacity of 0.309 MPa is obtained.

Background: Lung cancer is the most prevalent and deadly tumors around the world. Here we aimed to investigate the effect of wogonoside (also called baicalin) on the invasion and migration of lung cancer A549 cells and angiogenesis in xenograft tumors in nude mice. Methods: A549 cells of lung cancer were treated with different doses of wogonoside. After 24 h, CCK8 was used to detect the survival rate of cells. The non-toxic doses of wogonoside (0, 10, 25, and 50 µM) were selected for subsequent experiments. Transwell and scratch assays were used to detect invasion and migration. The number of microtubule nodules was detected by microtubule formation experiment, and the expressions of VEGF, E-cadherin, N-cadherin, and Vimentin were detected by Western blotting. BALB/c nude mice were subcutaneously injected with lung cancer A549 cells to establish the xenograft model, followed by intraperitoneal injection of 80 mg/kg of wogonoside. After 30 days, tumor volume was measured, and the levels of VEGF and vimentin were detected with immunohistochemistry. The level of CD34 was determined by flow sorting. Results: A549 cell survival decreased in a concentration-dependent manner, with the survival rate significantly reduced when the concentration of wogonoside exceeded 100 µM (P<0.05). A549 cell invasion and the number of microtubule nodules were significantly lower in the wogonoside 20 µM and the wogonoside 50 µM groups (P<0.05) compared with the wogonoside 0 µM group, while the rate of scratch closure and the protein levels of VEGF, N-cadherin, and Vimentin were all significantly reduced (P<0.05), and the expression level of E-cadherin was significantly increased (P<0.05). Compared with the control group, the tumor volumes of wogonoside (80 mg/kg) treated mice were significantly reduced after 30 days (P<0.05), and the levels of VEGF and vimentin positive cells were significantly reduced (P<0.05), as was the level of CD34 (P<0.05). Conclusions: Wogonoside can inhibit the invasion and migration of lung cancer A549 cells and angiogenesis of xenograft tumors in nude mice.