Locally resonant phononic crystals have excellent low-frequency characteristics and can result in a small size controlling a long wavelength. Based on the locally resonant phononic crystal theory, locally resonant pentamode metamaterials with composite materials are proposed and studied. The acoustic band frequencies of the locally resonant pentamode metamaterials were found to be two orders of magnitude smaller than those of conventional Bragg-Scattering pentamode metamaterials with the same lattice constant. Therefore, the single-mode frequency regions and locally resonant acoustic bandgaps which are under 110 Hz can be obtained by locally resonant pentamode metamaterials with a centimeter-scale lattice constant. The figure of merit can be increased by 60.78%–138.08%. This kind of locally resonant pentamode metamaterial opens a new path for applications in low-frequency acoustic cloaking and control of long wavelengths using small structure dimensions.

In this paper, the phononic band structures of Bragg scattering and locally resonant pentamode metamaterials (PMs) with single and composite materials symmetric double-cone elements (SDCEs) are calculated by using the finite element method. The numerical results show that, for the Bragg scattering PMs with single material SDCEs, the phononic band gaps (PBGs) can be obtained while the top touch cone diameters (TTCDs) (i.e. d) are much smaller than the bottom touch cone diameters (i.e. D), and the variation range of the PBGs frequency is mainly determined by the TTCDs. This indicates that the Bragg scattering PMs with single material SDCEs can be investigated as a phonon crystal. On this basis, the locally resonant SDCE PMs can be designed by using the composite SDCEs instead of single material SDCEs, and the PBGs can be obtained under the 100 Hz. This finding provides a way to control the low-frequency acoustics waves by using small-sized SDCEs PMs. In addition, compared with the Bragg scattering PMs, the relative bandwidth of the first PBGs of the locally resonant PMs can be expanded at least 25 times. In the end, the effect of mass density and Young’s modulus E of the composition material parameters of locally resonant SDCEs PMs on the PBGs is also studied by changing the parameters individually. The results show that the lower and upper edge and relative bandwidth of the first PBGs of locally resonant PMs with composite SDCEs are mainly impacted by the difference of the mass density between the two constituent materials, and the difference of the Young’s modulus E between the two constituent materials has little effect on the PBGs.

Background: Recent studies have shown that propofol and sevoflurane, two common anesthetics, can prevent tumor development. The prevalence of lung adenocarcinoma in China is highest in Yunnan Xuanwei, and many patients with lung cancer in this area are often resistant to platinum-based treatments. Objective: The objective of the study was to investigate the effects of propofol and sevoflurane on malignant biological behavior and cisplatin resistance of Xuanwei lung adenocarcinoma. Methods: Herein, XWLC-05/R, a cisplatin-resistant cell line of XWLC-05 cells from Xuanwei lung adenocarcinoma, was constructed. The XWLC-05 cells and XWLC-05/R cells were treated with propofol and sevoflurane singly or as a combination and subjected to CCK-8 assay, clone formation tests, and flow cytometry analysis to assess the proliferation level of cells. The morphology and number of apoptotic bodies in XWLC-05 cells and XWLC-05/R were examined with a transmission electron microscope. The ANNEXIN V-FITC/PI and transwell assays were performed to evaluate apoptosis, invasion, and migration of the cells. Subsequently, we constructed a Xuanwei lung adenocarcinoma xenograft model to investigate the effects of propofol and sevoflurane on the tumorigenicity of XWLC-05 cells in vivo. Results: Treatment with propofol and sevoflurane significantly inhibited proliferation, invasion, migration, and induced apoptosis of XWLC-05 and XWLC-05/R cells. These effects were more pronounced when propofol and sevoflurane were co-incubated with the cells. Moreover, both propofol and sevoflurane significantly inhibited Wnt/β- catenin and PI3K/AKT pathways. Moreover, the two drugs effects suppressed the malignant biological behavior of XWLC-05 cells and XWLC-05/R cells, and this effect was counteracted by 740Y-P (PI3K/AKT pathway activator) and Wnt pathway activator 1 (Wnt/β-catenin pathway activator). In vivo experiments confirmed that propofol and sevoflurane alleviated the tumorigenicity of XWLC-05 cells. Conclusions: In summary, this study shows, for the first time, that propofol and sevoflurane decrease the proliferation, invasion, migration and induce apoptosis of XWLC-05 cells and XWLC-05/R cells by impeding the Wnt/β-catenin and PI3K/AKT signaling pathways, thereby alleviating the development of Xuanwei lung adenocarcinoma in vivo. Moreover, these effects are more pronounced when the two drugs are combined.

The adjacent double-cones of the pentamode metamaterials form a connection overlap for the non-180° angle connection, and the overlap leads to a connection overlap deviation between the actual effective narrow touch diameters d′ and the defined narrow touch diameters d. The connection overlap deviation increases with the increasing of wide touch diameters D of the double-cones of the pentamode metamaterials with linear outside profile cones. In order to decrease the influence of the connection overlap deviation on the pentamode metamaterials, three types of pentamode metamaterials with small connection overlap (second and third order polynomial outside profile cones structures and the cones stacked by the cylinders-frustums) are proposed and studied in this paper. The connection overlap deviations of pentamode metamaterials with different outside profile cones are analyzed, the phononic band structures are calculated, and the ratio of bulk modulus B to shear modulus G are analyzed for evaluating fluid property. The results show that the pentamode metamaterials proposed by us have smaller connection overlap deviation and more excellent fluid properties than the pentamode metamaterials with linear outside profile cones. The ratio of bulk modulus to shear modulus can be increased by 7.47%–215.92% with the increasing of D from 1 mm to 9.6 mm.