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Developing mechanical metamaterials through topology optimization attracts high attention in both computational design and engineering applications. However, most of the studies in the literature are of quite limited applicability and poor extensibility. Hence, this work originally established an adaptable metamaterial topology optimization framework through integrating a commercial finite element analysis (FEA) platform. Particularly, the sensitivity analysis was derived and simplified to avoid the complex extraction of internal FEA information according to the strain-energy-based homogenization method. A series of two- and three-dimensional metamaterials with different properties, i.e., bulk and shear moduli, negative Poisson's ratio, were subsequently devised. These optimized metamaterials were fabricated and experimentally tested based on the additive manufacturing, firmly demonstrating the effectiveness of the developed design framework. This well-structured design framework can be conveniently extended to the systematic design of metamaterials with various other exclusive performances, fulfilling the urgent need for metamaterial design methods. [ABSTRACT FROM AUTHOR]

A fractional order sliding controller and a fractional proportional differential controller are designed for attitude and position of 5-DOF air-bearing simulator, respectively. Firstly, a new fuzzy parameter selftuning robust fractional sliding mode controller is designed for attitude platform model under considering gravity unbalance torque and actuator assembling error. The fractional differential operator is introduced in traditional sliding mode control because of its information memory and genetic characteristics, and then switching gain parameter is achieved self-tuning by fuzzy reasoning mechanism, so that the new controller has the multiple advantages of fuzzy control, fractional differential operator and sliding mode control. The stability of the whole system is proved by Fractional Lyapunov Theory. Secondly, a fractional proportional differential controller is proposed for translational platform considering coupling effects with attitude model. Finally, the actual operating characteristics of the actuator are considered in the process of the simulation. Numerical simulations are also included to reinforce the analytic results and to validate the excellent effect of the new robust fractional sliding mode controller. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) damages plant photosynthesis, affects roots and leaves growth, and triggers molecular responses. Riluzole (RIL), which protected neuronal damage via inhibiting excess Glu release in animals, has been found to improve Cd tolerance in duckweed in this study. Firstly, RIL treatment alleviated leaf chlorosis by protecting chlorophyll and decreased root abscission under Cd stress. Secondly, RIL declines Cd accumulation by alleviating excess Glu release during Cd shock. RIL mitigate Glu outburst in duckweed during Cd stress by a decline in Glu in roots. The Cd2+ influx was repressed by RIL addition with Cd shock. Finally, differentially expressed genes (DEGs) of duckweed under Cd stress with RIL have been investigated. 2141 genes were substantially up-regulated and 3282 genes were substantially down-regulated with RIL addition. RIL down-regulates the genes related to the Glu synthesis, and genes related to DNA repair have been up-regulated with RIL treatment under Cd stress. These results provide new insights into the possibility of RIL to reduce Cd accumulation and increase Cd tolerance in duckweed, and lay the foundation for decreasing Cd accumulation in crops. [Display omitted] • Cd stimulates Glu signal responses from root to above, showed by iGluSnFR transgenic duckweed. • Riluzole (RIL) addition enhanced Cd tolerance in duckweed. • RIL declines Cd accumulation by blocking Glu release during Cd stress, and down-regulates the genes related to the Glu synthesis. • Genes related to DNA repair have been up-regulated by RIL under Cd stress. [ABSTRACT FROM AUTHOR]

An nm-level positioning precision and high-speed are required by using macro movement of long stroke linear motor and high-precision micro movement of planar motor in the wafer stage of lithography. In order to reduce the movement scope and acceleration of planar motor, the tracking precision of linear motor must be improved, so this paper presents a combined control strategy based on the combination of zero phase error tracking controller with feed forward (ZPETC-FF) and the disturbance observer (DOB). ZPETC-FF is feed forward controller, which improves the system bandwidth and tracking performance effectively, and reduces the system's dynamic tracking error, while DOB reduces the influences of the uncertainties, such as external load disturbances, unmodeled dynamics and system parameter perturbation. The experiments show that compared with traditional control method, the proposed control method not only achieves more rapid and accurate tracking of the system, but also has stronger anti-interference ability. [ABSTRACT FROM AUTHOR]

Based on exposure characteristics of the wafer scanner, a segmented iterative learning control strategy is presented. The proposed method inherits the advantage of non-causal iterative learning control, which is full learning of errors. In order to improve the dynamic tracking performance, non-causal learning of errors in the last iteration is implemented during the acceleration phase, which guarantees the fast convergence of the system versus iteration domain. For the purpose of overcoming the weakness of blind learning for non-causal iterative learning control methods, errors are not learnt fully during the constant velocity so that exposure performance does not go bad. It improves the transient performance versus time. In addition, the convergence of the proposed method is analyzed and proved. Combining the numerical example, effectiveness of the method is testified. [ABSTRACT FROM AUTHOR]

To reduce the exchange time of dual-stage lithography, a modified fifth-order S-curve planning method and a minimum-time and minimum-jerk control method are proposed. The dual-driver and dual-bridge exchange method of the wafer stages is analyzed, and the wafer stages on the exposure position and pre-alignment position make five point-to-point movements to complete the exchange process. A minimum-jerk optimization index is added to fifth-order S-curve based on numerical integration method, and a modified fifth- order S-curve planning algorithm is proposed to ensure the acceleration curve is smooth. Aiming at a minimum-time and minimum-jerk criterion, an optimal control system is designed to reduce the exchange time and overcome the default of controlling the acceleration mutation only by the minimum-time Bang-Bang control. Simulation and experiment results show that the exchange process can be realized by trajectory planning and optimal control method. The acceleration curve of modified fifth-order S-curve is the most smooth, and minimum-time and minimum-jerk optimal control system can achieve a shorter exchange time. [ABSTRACT FROM AUTHOR]

In recent years, organophosphate ester flame retardants (OPFRs), which have been regarded as alternatives for brominated flame retardants (BFRs), have become widely used in building materials, textiles, and electric equipment. Elucidating the relationship between OPFRs and tumors holds great significance for the treatment and prevention of diseases. In this work, we found a new method for predicting the correlation between the interactive genes of OPFRs and tumors. Transcriptome profiles and OPFR information were obtained from The Cancer Genome Atlas and the Genotype–Tissue Expression, Comparative Toxicogenomics, and PharmMapper databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed that interactive genes were mainly enriched in prostate cancer, steroid metabolic process, and steroid hormone regulation. Furthermore, protein–protein interaction network analysis revealed 33 biological hub genes. The operating characteristic curves and survival analysis showed the role of key genes in predicting the prognosis of prostate cancer. Gene target prediction and gene set variation analysis proved that OPFRs and their metabolites exert potential effects on prostate cancer. Colony formation assay showed that the cells with AR, mTOR and DDIT3 knockdown could remarkably mitigate the cell proliferation ability in both PC-3 and LNCap cells. Transwell assay demonstrated that the silencing of AR, mTOR and DDIT3 could significantly inhibit the cell invasion capacity of prostate cells. Triphenyl phosphate (TPP) significantly increase the cell proliferation ability and promote cell invasion capacity. AR, mTOR and DDIT3 in the PC-3 and LNCap cells were significantly upregulated with 10–6 M TPP treated. [Display omitted] • We identified genes related to prostate cancer and OPFRs. • We verified the relationship between OPFRs-related genes and prostate cancer. • A total of 18 OPFRs and OPFRs metabolites were analyzed. • Colony formation assay and transwell assay were added for analysis and verification. [ABSTRACT FROM AUTHOR]

Changes in soil environmental factors and microbial communities of a precious tree species (Ormosia hosiei) plantation with different forest ages are still unclear. Obtaining this information can provide a theoretical basis for scientific forest management. Ormosia hosiei plantations of varying ages (7, 20, and 45 years old) were targeted in Zhejiang Province, China. We collected surface soil (0–20 cm) and analysed the diversity and structural characteristics of soil microbial communities by high-throughput sequencing. Redundancy analysis (RDA) and Spearman correlation analysis revealed soil environmental factors that cause differences in the microbial communities. The soil bacterial community diversity was not significantly affected by stand age, while the Chao and Ace indexes of the fungal community at 20 and 45 years were markedly higher than those at 7 years. The abundance of Proteobacteria in the 45 years was lower than those at 7 and 20 years, while the abundance of Actinobacteria at 7 years was lower than those at 20 and 45 years, and the abundance of Basidiomycota gradually increased with increasing stand age. The RDA and correlation analysis indicated that the soil microbial biomass carbon (MBC), bulk density (SBD), total porosity (STP), and total potassium (TK) were key factors that affected the bacterial communities and had a significant correlation with Actinobacteria. Soil temperature (T), available phosphorus (AP) and forest litter (FL) affected the fungal communities and had a significant correlation with Basidiomycota. In conclusion, forest age did not affect bacterial diversity, but the soil fungal community of the O. hosiei plantation in the middle-aged forest (20 years old) had the highest diversity; there were obvious differences in the composition and structure of soil microorganisms between different forest ages, which may be attributed to the phyla present (e.g., Proteobacteria , Actinobacteria , and Basidiomycota), which may be caused by differences in T, SBD, STP, AP, TK, MBC, and FL. • Forest age obviously changed the soil fungal community diversity. • The differences of soil microorganisms between different forest ages may be attributed to the phyla present. • Soil copiotrophic bacteria had the highest value at the middle-age forest. [ABSTRACT FROM AUTHOR]

Abstract: The draft genome of Pseudomonas monteilii strain IOFA19 isolated from deep-sea sediment of the Indian Ocean was sequenced to gain insights into its efficient metabolic pathway for degrading formaldehyde. The annotated genome of this strain was subjected to comparative analysis with the genomes of existing sequenced P. monteilii strains QM, SB3101, and SB3078. Differences in the overall genomic content were observed, and relative genes that were hypothetically involved in the formaldehyde-degrading mechanism were identified. [Copyright &y& Elsevier]