Parameter optimization of vibration control system for adjacent building structures based on negative stiffness inerter damper.

Building structures are subjected to strong earthquakes, which result in lateral collisions between them. Such collisions often cause severe structural damage and exacerbate the seismic hazard risk of building structures during earthquake events. This paper discusses the application of vibration control devices based on negative stiffness inerter damper in single-story adjacent building structures. The dynamic equations of the vibration control system containing different types of negative stiffness inerter damper under seismic excitation are established as a unified model. The H2 norm theory and Monte Carlo pattern search method are used to optimize the design parameters to improve the vibration control performance of the system, and the dynamic characteristics of the system are investigated. The results demonstrate that attaching negative stiffness inerter damper to adjacent building structures can effectively improve the overall seismic capacity reserve of the building and reduce the risk of collision of adjacent building structures; improve the robustness and stability of the system, and better reduce the displacement response of the building structure under seismic excitation. In addition, the potential of NSID-based vibration control devices to convert seismic energy into usable electricity has been investigated.

Effects of Valley Topography on Acoustic Communication in Birds: Why Do Birds Avoid Deep Valleys in Daqinggou Nature Reserve?

To investigate the effects of valley topography on the acoustic transmission of avian vocalisations, we carried out playback experiments in Daqinggou valley, Inner Mongolia, China. During the experiments, we recorded the vocalisations of five avian species, the large-billed crow (Corvus macrorhynchos Wagler, 1827), common cuckoo (Cuculus canorus Linnaeus, 1758), Eurasian magpie (Pica pica Linnaeus, 1758), Eurasian tree sparrow (Passer montanus Linnaeus, 1758), and meadow bunting (Emberiza cioides Brand, 1843), at transmission distances of 30 m and 50 m in the upper and lower parts of the valley and analysed the intensity, the fundamental frequency (F0), and the first three formant frequencies (F1/F2/F3) of the sounds. We also investigated bird species diversity in the upper and lower valley. We found that: (1) at the distance of 30 m, there were significant differences in F0/F1/F2/F3 in Eurasian magpies, significant differences in F1/F2/F3 in the meadow bunting and Eurasian tree sparrow, and partially significant differences in sound frequency between the upper and lower valley in the other two species; (2) at the distance of 50 m, there were significant differences in F0/F1/F2/F3 in two avian species (large-billed crow and common cuckoo) between the upper and lower valley and partially significant differences in sound frequency between the upper and lower valley in the other three species; (2) there were significant differences in the acoustic intensities of crow, cuckoo, magpie, and bunting calls between the upper and lower valley. (3) Species number and richness were significantly higher in the upper valley than in the lower valley. We suggested that the structure of valley habitats may lead to the breakdown of acoustic signals and communication in birds to varying degrees. The effect of valley topography on acoustic communication could be one reason for animal species avoiding deep valleys.

Sevoflurane Suppresses the Proliferation, Migration and Invasion of Colorectal Cancer Through Regulating Circ_0000423/miR-525-5p/SGPP1 Network.

Introduction: Sevoflurane (SEV) has been shown to inhibit the malignant progression in many cancers, including colorectal cancer (CRC). However, it is not clear whether SEV regulates the progression of CRC by mediating the circular RNA (circRNA) axis. Methods: Different concentrations of SEV were used to treat CRC cells. Cell proliferation, migration and invasion were determined by cell counting kit 8 assay, colony formation assay and transwell assay. The expression of circ_0000423, microRNA (miR)-525-5p and sphingosine-1-phosphate phosphatase 1 (SGPP1) mRNA was measured by quantitative real-time PCR. Cell apoptosis was assessed using flow cytometry, and protein expression was measured by western blot analysis. Dual-luciferase reporter assay and RIP assay were performed to confirm the interactions among circ_0000423, miR-525-5p and SGPP1. Animal experiments were performed to explore the effect of SEV and circ_0000423 on CRC tumorigenesis. Results: SEV could inhibit CRC cell proliferation, migration and invasion. Circ_0000423 was upregulated in CRC and its expression could be reduced by SEV. Overexpressed circ_0000423 reversed the inhibitory effect of SEV on CRC cell proliferation, migration and invasion and the promotion effect on cell apoptosis. MiR-525-5p could be sponged by circ_0000423, and its overexpression also abolished the regulation of circ_0000423 on the progression of SEV-treated CRC cells. In addition, SGPP1 was confirmed to be a target of miR-525-5p, and its expression was positively regulated by circ_0000423. MiR-525-5p inhibitor promoted CRC cell progression under the treatment of SEV, while these effects could be overturned by SGPP1 silencing. Furthermore, the inhibition effect of SEV on CRC tumorigenesis also could be abolished by overexpressing circ_0000423. Conclusion: Our results showed that SEV inhibited CRC progression through the regulation of circ_0000423/miR-525-5p/SGPP1 axis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-021-00717-5.

Sevoflurane blocks glioma malignant development by upregulating circRELN through circRELN-mediated miR-1290/RORA axis.

BACKGROUND: Sevoflurane (Sev) has been reported to inhibit cancer development, and sevoflurane treatment in cancers is implicated with the deregulation of specific non-coding RNAs (ncRNAs). This study aimed to investigate the relationship between sevoflurane and circular RNA reelin (circRELN) in glioma. METHODS: The expression of circRELN, microRNA-1290 (miR-1290) and RAR-related orphan receptor A (RORA) was measured by quantitative real-time PCR (qPCR). Cell proliferative capacity was assessed by cell counting kit-8 (CCK-8) and colony formation assays. Cell apoptosis and cell cycle distribution were monitored by flow cytometry assay. Cell migration was assessed by wound healing assay and transwell assay, and cell invasion was assessed by transwell assay. The protein levels of matrix metalloproteinase-2 (MMP2), MMP9 and RORA were quantified by western blot. Tumor growth in vivo was assessed by Xenograft models. The binding relationship between miR-1290 and circRELN or RORA was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. RESULTS: We found that circRELN expression was declined in glioma tissues and cells, while Sev treatment enhanced circRELN expression. In function, Sev notably inhibited glioma cell proliferation, migration and invasion and promoted apoptosis and cell cycle arrest, while circRELN knockdown reversed these effects. MiR-1290 served as a target of circRELN, and glioma cell malignant phenotypes recovered by circRELN knockdown were partly repressed by miR-1290 deficiency. In addition, RORA was a target of miR-1290, and glioma cell malignant phenotypes promoted by miR-1290 restoration were partly blocked by RORA overexpression. CircRELN regulated RORA expression by targeting miR-1290. In Xenograft models, Sev inhibited tumor growth by upregulating circRELN. CONCLUSION: Sev blocked the progression of glioma by increasing circRELN expression, and circRELN played roles in glioma partly by regulating the miR-1290/RORA network.

A flexible triboelectric nanogenerator based on a super-stretchable and self-healable hydrogel as the electrode.

Stretchable electronic devices nowadays have become more and more necessary in our daily lives, and most of the present electronic devices are based on inorganic materials. The obtained electronic devices can hardly bear various deformations in practical applications because of the poor flexibility and stretchability of these conventional inorganic materials. However, the biggest challenge for producing flexible and stretchable electronic devices is that each component of the device should endure deformations, and in the meantime, ensure that the whole electronic devices not only have excellent flexibility and stretchability, but also maintain excellent electrical output performances even under the situation of being deformed. In this work, a kind of super-stretchable, self-healable, and conductive hydrogel which could bear about sixty times stretching compared with its original state (∼ 6000%) is prepared; it could self-heal in about 10 min after being cut. More importantly, the hydrogel can greatly enhance the output performances of the TENG compared with the conventional copper foil as the electrode. Furthermore, when used as the electrode in flexible TENGs, relatively stable and excellent electrical output performances could be maintained even after being seriously stretched. Consequently, this study provides an ideal candidate for the electrode material of electric devices.

Boosting performances of triboelectric nanogenerators by optimizing dielectric properties and thickness of electrification layer.

Triboelectric nanogenerators (TENGs) with excellent flexibility and high outputs are promising for powering wearable/wireless electronics with electricity converted from ubiquitous mechanical energies in the working environment. In this work, the effects of the dielectric properties and thickness of the electrification film on the performance of the TENG are discussed. BaTiO3 nanoparticles are added into poly(vinylidene fluoride) (PVDF) to improve the dielectric constant of the composite film. The TENG using a BaTiO3/PVDF nanocomposite film with 11.25 vol% BaTiO3 as the tribo-negative electrification layer is demonstrated to be the optimized one, and generates an open-circuit voltage of 131 V and transferred short-circuit charge density of 89 µC m-2, 6.5 fold higher than those of a TENG using bare a PVDF layer. Furthermore, by reducing the thickness of the BaTiO3/PVDF film to 5 µm, the voltage and charge density increase to 161 V and 112 µC m-2, respectively, and an instantaneous peak power density of 225.6 mW m-2 is obtained.

[Protective effect of astaxanthin against epididymal oxidative damagein rats with ornidazole-induced oligoasthenozoospermia].

OBJECTIVE: To investigate the improving effect of astaxanthin (AST) on the sperm quality of rats with ornidazole (ORN)-induced oligoasthenozoospermiaand its action mechanism. METHODS: Forty adult male SD rats were equally randomized into groups A (solvent control), B (low-dose ORN ï¼»400 mg/（kg·d）］), C (high-dose ORN ï¼»800 mg/（kg·d）］), D (low-dose ORN ï¼»400 mg/（kg·d）］ + AST ï¼»20 mg/（kg·d）］), and E (high-dose ORN ï¼»800 mg/（kg·d）］ + AST ï¼»20 mg/（kg·d）］), all treated intragastrically for3 weeks.After treatment, the epididymal tails ononeside was taken for determination of sperm concentration and activity, and the epididymideson the other side harvested for measurement of the activities of GSH-Px, GR, CAT and SOD and the MDA contentin the homogenate. RESULTS: Compared with group A, sperm motilityin the epididymal tail andGSH-Px and SOD activities in theepididymiswere markedly decreased while the MDAcontent significantlyincreased in group B (P<0.05), spermmotility and concentrationin the epididymal tail, testisindex, and the activities of GSH-Px, GR, CAT and SOD in the epididymis were remarkably reduced while theMDA contentsignificantly increased in group C(P<0.05). In comparison with group B, group D showed markedly increased sperm motility (ï¼»45.3±8.7ï¼½% vs ï¼»66.3±8.9ï¼½%, P<0.05) in the epididymal tail and SOD activity in the epididymis (ï¼»116.7±25.3ï¼½ U/mg prot vs ï¼»146.1±23.8ï¼½ U/mg prot, P<0.05), decreased MDA content(ï¼»1.68±0.45ï¼½ nmol/mg prot vs ï¼»1.19±0.42ï¼½ nmol/mg prot, P<0.05).Compared with group C, group Eexhibited significant increases in the weight gained (ï¼»89.0±9.5ï¼½ vs ï¼»99.9±4.1ï¼½ %, P<0.05) and sperm motility (ï¼»17.9±3.5ï¼½% vs ï¼»27.3±5.3ï¼½ %, P<0.05) but a decrease in the content of MDA (ï¼»2.03±0.30ï¼½ nmol/mg prot vs ï¼»1.52±0.41ï¼½ nmol/mg prot, P<0.05). CONCLUSIONS: AST can improve spermquality in rats with ORN-inducedoligoasthenozoospermia, which may be associated with its enhancing effect on the antioxidant capacity of the epididymis.

[Astaxanthin in male reproduction: Advances in studies].

Astaxanthin (AST) is a carotenoid with a strong antioxidant activity and has many biological functions, such as anti-inflammation, immune regulation, anti-tumor, anti-oxidation, anti-aging, and anti-apoptosis. Recent studies show that AST can effectively regulate the dynamic balance between oxidation and antioxidants in the male reproductive system, protect sperm mitochondrial function, ameliorate testicular heat stress and reproductive poison damage, promote the occurrence of sperm capacitation and acrosome reaction, regulate reproductive endocrine hormone balance, and act favorably on primary infertility or metabolic syndrome-related infertility. It also helps the treatment of late-onset hypogonadism and prostate health care. This review updates the studies of AST in male reproductive health and provides some new ideas for the prevention and treatment of male reproductive problems.