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Radiation enteritis (RE) is the most common radiotherapy complication, and effective RE treatments are lacking. Resveratrol exerts beneficial effects on radiation injury. However, the effect of resveratrol in radiation-induced intestinal injury and the underlying mechanism remain unclear. Here, a C57BL/6 mouse model of RE was established and an intestinal epithelial cell line was used to evaluate the protective effects of resveratrol against radiation-induced intestinal injury and the underlying mechanisms. Resveratrol improved radiation-induced oxidative stress and cell apoptosis via upregulating antioxidant enzymes and downregulating p53 acetylation. In vivo , resveratrol-treated mice exhibited longer survival; longer villi; more intestinal crypt cells; upregulated expression of Ki67, catalase, and superoxide dismutase 2; and fewer inflammatory proteins and apoptotic cells. These protective effects were suppressed by inhibition of SIRT1. These results demonstrate that resveratrol can reduce radiation-induced intestinal injury by inhibiting oxidative stress and apoptosis via the SIRT1/FOXO3a and PI3K/AKT pathways. • Resveratrol pretreatment attenuated radiation-induced intestinal injury in mice. •Resveratrol mitigated irradiation-induced IEC-6 cell injury. •Resveratrol activated the SIRT1/FOXO3a pathway to inhibit oxidative stress. •The PI3K/AKT pathway may aid resveratrol protective effects against radiation. [ABSTRACT FROM AUTHOR]

• A new MRE metamaterial plate with continuous programmable properties was proposed. • A real-time tunable and fast response local resonant band gap was generated. • The plane wave expansion method and the finite element method were implemented. • The vibration manipulation functionalities were experimentally verified. Metamaterial plates have attracted considerable attention due to their unprecedented elastic wave manipulation abilities. Currently, the band gap and other properties of traditional metamaterial plates are fixed, and the material parameters of most metamaterials cannot be dynamically and continuously adjusted. To address this issue, a two-dimensional (2D) magnetorheological elastomer (MRE) programmable metamaterial plate (MREPMP) with local resonance was proposed. The proposed MREPMP was composed of a thin steel plate and a periodic array of resonators, consisting of MREs and electromagnetic mass blocks. It not only has a compact structural design, but also enables real-time vibration control and programming wave manipulation by altering the amplitude of the current. The dispersion relation of the proposed MREPMP was theoretically calculated based on the plane wave expansion (PWE) method and the simulated transmissibility was numerically calculated using the finite element method in COMSOL. Subsequently, a prototype of the MREPMP was fabricated, and vibration tests were conducted to assess its programmable vibration manipulation functionalities. Two different types of defect paths were used as excitations and the corresponding real-time vibration manipulation performance was analyzed. The simulation results agree with the experimental results, showing that the MREPMP can dynamically tune the band gap and activate different waveguides through continuous online programming. This paper opens up a new idea for tunable manipulation of wave propagation. [Display omitted] [ABSTRACT FROM AUTHOR]

Background Colorectal cancer (CRC) is a common cancer with high morbidity and mortality. However, its molecular mechanism is not clear, nor the genes related to CRC stages. Methods Gene expression data in CRC and healthy colorectal tissues were obtained from gene expression omnibus. Limma package was used to identify the differentially expressed genes (DEGs) between control and CRC (stage I, II, III, and IV), obtaining 4 DEG sets. VennPlex was utilized to find all DEGs and intersection DEGs. Functional interactions between all DEGs and protein-protein interactions (PPIs) between intersection DEGs were analyzed using ReactomeFIViz and STRING, respectively, and networks were visualized. Known CRC-related genes were down-loaded from Comparative Toxicogenomics Database and mapped to PPI network. Results Totally, 851, 760, 729, and 878 DEGs were found between control and CRC stage I, II, III, and IV, respectively. Taken together, 1235 DEGs were found, as well as 128 up-regulated intersection DEGs, 365 down-regulated intersection DEGs, and 0 contra-regulated DEG. A functional interaction network of all DEGs and a PPI network of intersection DEGs were constructed, in which CDC20, PTTG1, and MAD2L1 interacted with BUB1B; UGT2B17 interacted with ADH1B; MCM7 interacted with MCM2. BUB1B, ADH1B, and MCM2 were known CRC-related genes. Gradually upregulated expressions of CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 in stage I, II, III, and IV CRC were confirmed by using quantitative PCR. Besides, up-regulated intersection DEGs enriched in pathways about Cell cycle, DNA replication, and p53 signaling. Conclusion CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 might be CRC stage-related genes. [ABSTRACT FROM AUTHOR]

A wideband energy harvester has been designed, fabricated, and tested based on an array of four parametrically excited cantilever beams; the cantilever beams carry a tip mass at their free end. Piezoelectric transduction has been used to convert between the mechanical and electrical domains. An array configuration in conjunction with parametric excitation generated an enhanced bandwidth of the device (at low frequencies); furthermore, each piezoelectric beam displayed nonlinear dynamical behaviour due to geometric extensibility at the centreline—this behaviour was used to further increase the bandwidth of the energy harvester. An electrodynamic shaker has been used to parametrically excite the energy harvester, and the corresponding voltage of each piezoelectric beam has been measured. It was observed the energy harvester displayed eight resonance peaks that are within close proximity of each other, particularly, for low frequency applications (below 13 Hz); each piezoelectric beam generated substantial power (in the milli-Watt range). [ABSTRACT FROM AUTHOR]

• A novel metamaterial MRE sandwich beam in a compact design was proposed. • The MRE and the local coil resonators were periodically arranged as the core layer. • A real-time tunable local resonance band gap was generated for vibration isolation. • A model using the Timoshenko beam theory and transfer matrix method was developed. • The low-frequency band gap can be controlled by adjusting the applied current. • The larger the current, the stronger the magnetic field and the higher the band gap. The effectiveness of the sandwich beam structure on vibration attenuation has been extensively investigated in diverse engineering applications. As the evolvement of the metamaterial structure into sandwich beam can further improve the vibration attenuation performance, a novel metamaterial magnetorheological elastomer (MRE) sandwich beam (MMRESB) in a compact design was proposed in this study to generate a real-time tunable local resonance band gap for vibration isolation. The controllable band gap behavior and the transmission spectrum were investigated theoretically based on the Timoshenko beam theory and the transfer matrix method. Subsequently, experiments were conducted to evaluate the controllability of the band gap and its vibration transmissibility properties. The results show that as the applied current increases from 0.0 A to 1.0 A, the compact MMRESB with local coil resonators can autonomously tune its band gap from 52.3–92.8 Hz to 56.5–98.9 Hz, and that the compact MMRESB can significantly suppress the vibration wave propagation along the beam. [ABSTRACT FROM AUTHOR]

• A novel compact rotary MR damper with variable stiffness and variable damping characteristics was designed and prototyped for the seat suspension. • The nonlinear stiffness control scheme can avoid the end-stop impact and dissipate vibration energy. • The no-jerk skyhook damping control scheme can reduce the vibration amplitude. • The vibration attenuation performance of the seat suspension was largely improved by the VSVD rotary MR damper. Long-term vibration poses a threat to drivers' health and affects their ride performance. Furthermore, large-magnitude vibration and sudden shocks may even result in end-stop impacts, raising the drivers' injury risk. To reduce the vibration and avoid end-top impacts, this paper presents an innovative seat suspension installed with variable stiffness and variable damping (VSVD) rotary magnetorheological (MR) dampers. At first, a novel compact VSVD rotary MR damper was designed and prototyped for the suspension, making the suspension's stiffness and damping controllable. Then, with two identical VSVD MR dampers were installed, the prototyped seat suspension was characterised by an MTS test frame to verify its capabilities of variable stiffness and damping. A control strategy consisting of a nonlinear stiffness control and a no-jerk skyhook damping control was also designed. Finally, the vibration attenuation performance of the seat suspension was numerically and experimentally evaluated under three vibration excitations, i.e., harmonic excitation, bump excitation, and random excitation. Both numerical and experimental results indicate that the vibration control performance of the seat suspension can be significantly improved by the VSVD rotary MR dampers. [ABSTRACT FROM AUTHOR]

• A new metamaterial MRE isolator with tunable vibration bandgaps is proposed. • A spring-mass model is built for theoretically analyses of the metamaterial MRE isolator. • The vibration isolation effectiveness increases greatly among the vibration bandgaps. • The tunable vibration bandgaps enlarge the effective frequency range of the isolator. Semi-active isolators with laminated magnetorheological elastomer (MRE) structures draw increasing attentions for vibration control because of their resonance-frequency-shift property. Their vibration attenuation capacity can be further improved by integrating the acoustic metamaterial characteristics with tunable vibration bandgaps at designed frequencies. On this basis, a novel metamaterial MRE isolator with controllable vibration bandgaps was designed and prototyped. The mechanism of the formation of vibration bandgaps was analysed theoretically using the method of mass-spring model. Both infinite and finite periodic structures were discussed respectively. The equivalent negative stiffness of the metamaterial MRE isolator was studied. The evaluation experiments were conducted to study bandgaps of the metamaterial MRE isolator and its vibration isolation capacity. Results demonstrate that the new metamaterial MRE isolator possesses controllable bandgaps and can provide improved vibration isolation performance. [ABSTRACT FROM AUTHOR]