Dynamic performance and parameter optimization of a half-vehicle system coupled with an inerter-based X-structure nonlinear energy sink

Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the IX-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the IX-NES. Furthermore, the structural parameters of the IX-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the IX-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly larger.When the structural parameters of the IX-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ranges.Thus, the IX-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibration attenuation in the vehicle engineering.

Integrative multiomics analysis identifies a metastasis-related gene signature and the potential oncogenic role of EZR in breast cancer

Distant metastasis is a major cause of increased mortality in breast cancer patients,but the mechanisms underlying breast cancer metastasis remain poorly understood.In this study,we aimed to identify a metastasis-related gene(MRG)signature for predicting progression in breast cancer.By screening using three regression analysis methods,a 9-gene signature(NOTCH1,PTP4A3,MMP13,MACC1,EZR,NEDD9,PIK3CA,F2RL1 and CCR7)was constructed based on an MRG set in the BRCA cohort from TCGA.This signature exhibited strong robustness,and its generalizability was verified in the Metabric and GEO cohorts.Of the nine MRGs,EZR is an oncogenic gene with a well-documented role in cell adhesion and cell migration,but it has rarely been investigated in breast cancer.Based on a search of different databases,EZR was found to be significantly more highly expressed in both breast cancer cells and breast cancer tissue.EZR knockdown significantly inhibited cell proliferation,invasion,chemoresistance and EMT in breast cancer.Mechanistically,RhoA activation assays confirmed that EZR knockdown inhibited the activity of RhoA,Rac1 and Cdc42.In summary,we identified a nine-MRG signature that can be used as an efficient prognostic indicator for breast cancer patients,and owing to its involvement in regulating breast cancer metastasis,EZR might serve as a therapeutic target.

Microcystis aeruginosa/Pseudomonas pseudoalcaligenes interaction effects on off-flavors in algae/bacteria co-culture system under different temperatures

We conducted an experiment to study the interaction effects of Microcystis aeruginosa and Pseudomonas pseudoalcaligenes on off-flavors in an algae/bacteria co-culture system at three temperatures（24, 28 and 32℃）. Gas chromatography-mass spectrometry was applied to measure off-flavor compounds dimethyl sulfide（DMS）, dimethyl trisulfide（DMTS）,2-methylisoborneol, geosmin（GEO） and β-cyclocitral. During the lag phase of co-cultured M. aeruginosa（first 15 days）, P. pseudoalcaligenes significantly increased the production of DMS, DMTS and β-cyclocitral at all three temperatures. In the exponential phase of co-cultured M. aeruginosa（after 15 days）, M. aeruginosa became the main factor on off-flavors in the co-culture system, and β-cyclocitral turned to the highest off-flavor compound. These results also indicated that DMS, DMTS and β-cyclocitral were the main off-flavor compounds in our M. aeruginosa/P. pseudoalcaligenes co-culture system. Univariate analysis was applied to investigate the effects of M. aeruginosa and P. pseudoalcaligenes on the production of off-flavors. The results demonstrated that both M. aeruginosa and P. pseudoalcaligenes could increase the production of DMS and DMTS, while β-cyclocitral was mainly determined by M. aeruginosa. Our results also provide some insights into understanding the relationship between cyanobacteria and heterotrophic bacteria.