RESUMO
Introduction: Since tracked mobile robot is a typical non-linear system, it has been a challenge to achieve the trajectory tracking of tracked mobile robots. A zeroing neural network is employed to control a tracked mobile robot to track the desired trajectory. Methods: A new fractional exponential activation function is designed in this study, and the implicit derivative dynamic model of the tracked mobile robot is presented, termed finite-time convergence zeroing neural network. The proposed model is analyzed based on the Lyapunov stability theory, and the upper bound of the convergence time is given. In addition, the robustness of the finite-time convergence zeroing neural network model is investigated under different error disturbances. Results and discussion: Numerical experiments of tracking an eight-shaped trajectory are conducted successfully, validating the proposed model for the trajectory tracking problem of tracked mobile robots. Comparative results validate the effectiveness and superiority of the proposed model for the kinematical resolution of tracked mobile robots even in a disturbance environment.
RESUMO
Metal-organic frameworks (MOFs) are one of the most promising adsorbents in the adsorption cooling system (ACS) for their outstanding water adsorption performance. Notwithstanding that fact, numerous reports pay more attention to the ACS performance improvement through enhancing equilibrium water uptake of MOFs. However, adsorption cooling performance, including specific cooling power (SCP) and coefficient of performance for cooling (COPC) of MOF/water working pairs, always depends on the water adsorption kinetics of MOFs in ACS. In this work, to increase the water adsorption rate, the preparation of MOP/MIL-101(Cr) was achieved by encapsulating hydrophilic metal-organic polyhedral (MOP) into MIL-101(Cr). It was found that the hydrophilicity of MOP/MIL-101(Cr) was enhanced upon hydrophilic MOP3 encapsulation, resulting in a remarkable improvement in water adsorption rates. Furthermore, both SCP and COPC for MOP/MIL-101(Cr)-water working pairs were also improved because of the fast water adsorption of MOP/MIL-101(Cr). In brief, an effective approach to enhance the water adsorption rate and cooling performance of MOF-water working pairs through enhancing the hydrophilicity of MOFs by encapsulating MOP into MOFs was reported in this work, which provides a new strategy for broadening the application of MOF composites in ACS.
RESUMO
DACH1 is an important component of the retinal determinate gene network (RDGN), which regulates the expression of target genes by directly binding or interacting with other factors. DACH1 shows inhibitory effects in most tumors, but its role in papillary thyroid carcinoma is unclear and warrants further investigation. We assessed the expression of DACH1 in different tissues and correlation with immune infiltration by The Cancer Genome Atlas (TCGA) and Tumor Immune Estimation Resource (TIMMER2.0 databases). The effects of DACH1 on the proliferation and migration of TPC-1 and Bcpap cells were assessed by cell viability assay, colony formation assay, wound healing assay, transwell migration assay, and flow cytometry. Finally, the effects of DACH1 on CXCL8, CXCL10, and CXCL12 expression in Nthy-ori-3-1, TPC-1 and Bcpap cells were assessed by enzyme-linked immunosorbent assay kit and real-time polymerase chain reaction, respectively. The results showed that DACH1 was differentially expressed in different tumors and tissues. Basal expression of DACH1 was lower in thyroid and papillary thyroid carcinoma than in other normal tissues and corresponding tumors, and positively correlated with CD8+ T cell infiltration. In Nthy-ori-3-1, TPC-1 and Bcpap cells, overexpression of DACH1 inhibited cell migration and proliferation, and the opposite results was obtained by knocking down DACH1 using small interfering RNA. We also demonstrated that DACH1 regulated chemokines CXCL8, CXCL10, and CXCL12, thereby modulating tumor immunity.
