In recent decades,the application of seismic metamaterials to protect civil infrastructures being free of the damage of earthquakes has been attracting extensive attention.Specifically,the proposed locally resonant se...In recent decades,the application of seismic metamaterials to protect civil infrastructures being free of the damage of earthquakes has been attracting extensive attention.Specifically,the proposed locally resonant seismic metamaterials provide the probability of isolating the low-frequency seismic wave using a small-size isolation barrier.However,in previous studies,the energy absorption properties of locally resonant seismic metamaterials remain one of the least understood aspects of isolation.Benefit from the fascinating energy absorption characteristic of negative Poisson ratio(NPR)metamaterial,we creatively design a new seismic metamaterial structure by assembling the locally resonant seismic metamaterial and NPR metamaterial,to isolate seismic waves.The sound cone technique combining the transmission spectrum is employed to identify the surface wave from the hybrid waves.The generation mechanism of frequency bandgap and the isolation effectiveness of the proposed seismic metamaterial are discussed in detail.The results indicate that the generation of ultra-low and ultra-wide frequency bandgap with the range of 0.65 Hz–18.9 Hz is attributed to the locally resonant and energy absorption of the proposed seismic metamaterial structure and the excellent isolation effect is achieved by transforming the surface wave into the bulk wave.The frequency bandgap narrows as the distance increases between each resonator.In addition,the mechanical properties of the NPR bearing,such as the Poisson ratio,mass density,and elastic modulus,have remarkable impact on the frequency bandgap,especially on the upper bound frequency.In practical engineering,the NPR bearing with a low Poisson ratio,small mass density,and high elastic modulus is suggested for the design of the NPR locally resonant seismic metamaterial structures.Time domain analysis for the practical seismic wave verifies that the proposed seismic metamaterial has a promising application in isolating ultra-low and ultra-wide seismic waves,with the isolation effectiveness larger than 70%.This work contributes a new locally resonance seismic metamaterial design idea for isolating and adjusting the low-frequency seismic wave.展开更多
More than 50%of prostate cancer(PCa)patients have bone metastasis with osteo-blastic lesions.MiR-18a-5p is associated with the development and metastasis of PCa,but it remains unclear whether it is involved in osteobl...More than 50%of prostate cancer(PCa)patients have bone metastasis with osteo-blastic lesions.MiR-18a-5p is associated with the development and metastasis of PCa,but it remains unclear whether it is involved in osteoblastic lesions.We first found that miR-18a-5p was highly expressed in the bone microenvironment of patients with PCa bone metastases.To address how miR-18a-5p affects PCa osteoblastic lesions,antagonizing miR-18a-5p in PCa cells or pre-osteoblasts inhibited osteoblast differentiation in vitro.Moreover,injection of PCa cells with miR-18a-5p inhibition improved bone biomechanical properties and bone mineral mass in vivo.Furthermore,miR-18a-5p was transferred to osteoblasts by exosomes derived from PCa cells and targeted the Hist1h2bc gene,resulting in Ctnnb1 up-regulation in the Wnt/β-catenin signaling pathway.Translationally,antagomir-18a-5p significantly improved bone biomechanical properties and alleviated sclerotic lesions from osteoblastic me-tastases in BALB/c nude mice.These data suggest that inhibition of exosome-delivered miR-18a-5p ameliorates PCa-induced osteoblastic lesions.展开更多
基金supported by the National Natural Science Foundation(Grant Nos.52208344 and 52278350)the Natural Science Foundation of Jiangxi Province(Grant Nos.20224BAB214068 and 20212BDH81034)+1 种基金Education Department of Jiangxi Province(Grant No.GJJ2200673)Open Project of State Key Laboratory(Grant No.HJGZ2022204).
文摘In recent decades,the application of seismic metamaterials to protect civil infrastructures being free of the damage of earthquakes has been attracting extensive attention.Specifically,the proposed locally resonant seismic metamaterials provide the probability of isolating the low-frequency seismic wave using a small-size isolation barrier.However,in previous studies,the energy absorption properties of locally resonant seismic metamaterials remain one of the least understood aspects of isolation.Benefit from the fascinating energy absorption characteristic of negative Poisson ratio(NPR)metamaterial,we creatively design a new seismic metamaterial structure by assembling the locally resonant seismic metamaterial and NPR metamaterial,to isolate seismic waves.The sound cone technique combining the transmission spectrum is employed to identify the surface wave from the hybrid waves.The generation mechanism of frequency bandgap and the isolation effectiveness of the proposed seismic metamaterial are discussed in detail.The results indicate that the generation of ultra-low and ultra-wide frequency bandgap with the range of 0.65 Hz–18.9 Hz is attributed to the locally resonant and energy absorption of the proposed seismic metamaterial structure and the excellent isolation effect is achieved by transforming the surface wave into the bulk wave.The frequency bandgap narrows as the distance increases between each resonator.In addition,the mechanical properties of the NPR bearing,such as the Poisson ratio,mass density,and elastic modulus,have remarkable impact on the frequency bandgap,especially on the upper bound frequency.In practical engineering,the NPR bearing with a low Poisson ratio,small mass density,and high elastic modulus is suggested for the design of the NPR locally resonant seismic metamaterial structures.Time domain analysis for the practical seismic wave verifies that the proposed seismic metamaterial has a promising application in isolating ultra-low and ultra-wide seismic waves,with the isolation effectiveness larger than 70%.This work contributes a new locally resonance seismic metamaterial design idea for isolating and adjusting the low-frequency seismic wave.
基金supported by the National Natural Science Foundation of China(No.81930067)Key Project for Clinical Innovation of AMU(China)(No.CX2019LC107).
文摘More than 50%of prostate cancer(PCa)patients have bone metastasis with osteo-blastic lesions.MiR-18a-5p is associated with the development and metastasis of PCa,but it remains unclear whether it is involved in osteoblastic lesions.We first found that miR-18a-5p was highly expressed in the bone microenvironment of patients with PCa bone metastases.To address how miR-18a-5p affects PCa osteoblastic lesions,antagonizing miR-18a-5p in PCa cells or pre-osteoblasts inhibited osteoblast differentiation in vitro.Moreover,injection of PCa cells with miR-18a-5p inhibition improved bone biomechanical properties and bone mineral mass in vivo.Furthermore,miR-18a-5p was transferred to osteoblasts by exosomes derived from PCa cells and targeted the Hist1h2bc gene,resulting in Ctnnb1 up-regulation in the Wnt/β-catenin signaling pathway.Translationally,antagomir-18a-5p significantly improved bone biomechanical properties and alleviated sclerotic lesions from osteoblastic me-tastases in BALB/c nude mice.These data suggest that inhibition of exosome-delivered miR-18a-5p ameliorates PCa-induced osteoblastic lesions.
