Multi-stage trajectory tracking of robot manipulators under stochastic environments.

For robot manipulators composed of Lagrange subsystems driven by direct current (DC) motors under stochastic environments, multi-stage trajectory tracking is investigated in this paper. The main challenge is how to achieve the end-effector drive of manipulators from a given initial state to a final state. First, the inverse kinematics method and the partition of the task space are adopted to tackle multi-stage trajectory planning. Second, the adaptive backstepping technique is used to design tracking controller for stochastic Lagrangian subsystems. Then, based on the state-dependent switching signal, a multi-stage switched controller is designed for trajectory tracking of robot manipulators. All signals in the close-loop error switched system are bounded in probability, and the tracking error in mean square can be made arbitrarily small enough by parameters-tuning The effectiveness of the proposed control method is illustrated by simulation results.

Molecular mechanism of modified Huanglian Wendan decoction in the treatment of polycystic ovary syndrome.

To investigate the mechanism of modified Huanglian Wendan decoction in the intervention of polycystic ovary syndrome (PCOS) by network pharmacology and molecular docking. The ingredients and targets of modified Huanglian Wendan decoction were retrieved from the traditional Chinese medicine Systems Pharmacology database. Related targets of PCOS were screened by Comparative Toxicogenomics Database database. Cytoscape 3.7.2 (https://cytoscape.org/) was used to draw the target network diagram of "traditional Chinese medicine - ingredient - PCOS," STRING database was used to construct the target protein interaction network. NCA tool of Cystoscape 3.7.2 was used to carried out topology analysis on PPI network, core components and key targets were obtained. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis were carried out for the intersection targets by David database. AutoDockTools 1.5.6 software (https://autodock.scripps.edu/) was used to conduct molecular docking verification of key components and key targets. Ninety-one ingredients of the modified Huanglian Wendan decoction and 23,075 diseases targets were obtained, 155 Intersection targets of the drug and disease were obtained by R language, Veen plot was drawn. Gene ontology enrichment analysis obtained 432 biological processes, 67 cell components, 106 molecular functions. Fifty-four Kyoto encyclopedia of genes and genomes enrichment pathways (P < .05) including tumor necrosis factor, hypoxia-induced factors-1, calcium, and drug metabolism-cytochrome P450 signaling pathway. Molecular docking showed quercetin, luteolin, kaempferol, and baicalein were stable in docking with core targets. Network pharmacology and molecular docking were used to preliminarily study the mechanism of action of modified Huanglian Wendan decoction in the treatment of PCOS, which laid foundation for future experimental research and clinical application.

Fuzzy event-triggered tracking control for nonlinear unreliable networked systems.

This article addresses a fuzzy event-triggered tracking control problem of unreliable networked systems. An event-based tracking controller is put forward to control the plant in fuzzy form. The looped Lyapunov-Krasovskii functional method is made use of conducting stability analysis, and sufficient conditions on the controller are determined. As a result, the tracking control performance is achieved for the controlled system. The feasibility of the presented tracking control design is verified by some examples.

Reinforcement Learning-Based Tracking Control for a Three Mecanum Wheeled Mobile Robot.

This brief investigates the robust optimal tracking control for a three Mecanum wheeled mobile robot (MWMR) with the external disturbance by the aid of online actor-critic synchronous learning algorithm. The Euler-Lagrange motion equation of MWMR subject to slipping is established by analyzing the structural characteristics of Mecanum wheels. Concatenating the tracking error with the desired trajectory, the tracking control problem is converted into a time-invariant optimal control problem of an augmented system. Then, an approximate optimal tracking controller is obtained by applying online actor-critic synchronous learning algorithm. With the help of Lyapunov-based analysis, the ultimately bounded tracking can be guaranteed. Finally, simulation results show the effectiveness of synchronous learning algorithm and approximate optimal tracking controller.

Study the Mechanism of Gualou Niubang Decoction in Treating Plasma Cell Mastitis Based on Network Pharmacology and Molecular Docking.

Objective: Explore the potential molecular mechanisms behind the therapeutic functions of Gualou Niubang decoction (GLNBD) in the treatment of plasma cell mastitis (PCM) by network pharmacology and molecular docking. Methods: GLNBD is a formula of Chinese traditional medicine consisting of 12 herbs. The potential active ingredients of GLNBD and their target genes were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database, and PCM-related target genes were obtained from GeneCards, OMIM, and NCBI databases, using R language to obtain intersection targets; then, the STRING database and Cytoscape software were used to establish protein-protein interaction networks and herb ingredient target networks. DAVID was used to perform GO and KEGG pathway enrichment analyses on the intersection target. PyMoL-2.5.0 and AutoDock Tools-1.5.6 were used to verify the molecular docking. Results: 164 ingredients and 58 intersection targets were obtained in the treatment of PCM by GLNBD. Four key active compounds and four key proteins were identified. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that biological functions of potential target genes were associated with negative regulation of the apoptotic process, response to hypoxia, positive regulation of transcription, and DNA-templated, with related pathways involving the pathway in cancer, phosphatidylinositol 3-kinase (PI3K) Akt signaling pathway, and AGE-RAGE signaling pathway in diabetic complications. Moreover, the binding activities of key target genes and essential active compounds of Chinese herbal medicines in GLNBD were further validated by molecular docking. The results showed that the docking results were stable and had good binding ability. Conclusion: This study suggested that four potential key active components, including quercetin, luteolin, fisetin, and kaempferol, were identified in GLNBD, which could interact with ALB, EGFR, IL-6, and VEGFA modulating the activation of the pathway in cancer, PI3K-Akt pathway, and AGE-RAGE signaling pathway in diabetic complications.

Enhancement of Solubility, Purification, and Inclusion Body Refolding of Active Human Mitochondrial Aldehyde Dehydrogenase 2.

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is predominantly linked with acetaldehyde detoxification in the second stage of alcohol metabolism. To intensively study ALDH2 function, a higher purity and uniform composition of the protein is required. An efficient Escherichia coli system for ALDH2 expression was developed by using His and a small ubiquitin-related modifier fusion tag. Most of the recombinant ALDH2s were expressed in the form of inclusion bodies. The ALDH2-enriched inclusion bodies were denatured with 6 M guanidine hydrochloride, and then ALDH2 was ultrafitrated. Finally, ALDH2 was successfully purified through affinity and gel filtration chromatography. The purified ALDH2 was finally preserved by the vacuum freeze-drying method, and its purity was determined to be higher than 95%, with a final media yield of 33.89 mg/L. The specific activity of ALDH2 was 6.1 × 104 U/mg. This work was the first to report pET-SUMO-ALDH2 recombinant plasmid expression in Escherichia coli, and the inclusion bodies were isolated and refolded. Finally, the purified ALDH2 had relatively higher purity, yield, and biological activity.

Long-term low-dose ethanol intake improves healthspan and resists high-fat diet-induced obesity in mice.

Numerous epidemiological studies have reported that moderate alcohol drinking has beneficial effects. However, few studies have focused on the beneficial effects of ethanol, the common component in alcoholic beverages. Here we fed the C57BL/6 mice with 3.5% v/v ethanol as drinking water substitute to investigate the effects of long-term low-dose ethanol intake in vivo. We evaluated the metabolic rate and mitochondrial function of the long-term low-dose ethanol-intake (LLE) mice, assessed the exercise ability of LLE mice, and fed the LLE mice with a high-fat diet to investigate the potential impact of ethanol on it. The LLE mice showed improved thermogenic activity, physical performance, and mitochondrial function, as well as resistance against the high-fat diet-induced obesity with elevated insulin sensitivity and subdued inflammation. Our results suggest that long-term low-dose ethanol intake can improve healthspan and resist high-fat diet-induced obesity in mice. It may provide new insight into understanding the protective effects of moderate alcohol drinking.

Low-dose ethanol intake prevents high-fat diet-induced adverse cardiovascular events in mice.

A high-fat diet is recognized as an important factor in the development of cardiovascular diseases including cardiomyopathy. Besides high-fat diets, large quantities of ethanol also induce cardiomyopathy in both animals and humans. Emerging evidence suggests that low ethanol intake may have a protective effect on the cardiovascular system. This study aimed to clarify whether low-dose ethanol intake could prevent high-fat diet-induced adverse effects on cardiomyocytes in mice. After 6-8 weeks of feeding, the heart weight significantly decreased in ethanol + HFD mice compared to HFD mice. In addition, cardiac triglycerides and lipid droplets also decreased, but no statistically significant difference in cholesterol level was found between the two groups. Expression of the fatty acid transporters Cd36, Slc27a1 and Got2 was downregulated in the ethanol + HFD group. According to echocardiography, the mass and volume of the left ventricle were reduced, and the ejection fraction (EF) and fractional shortening (FS) were increased in mice fed with alcohol. Low doses of ethanol reduced the cardiomyocytes' cross-sectional area and the expression of the hypertrophic markers ANP and BNP. Moreover, Col1a1, the main collagen type expressed in the heart, was also reduced by low-dose ethanol consumption. Also, the expression of Rgs5, a crucial component of the signaling pathway involved in cardiac remodeling and heart failure, was upregulated in response to ethanol intake. The data suggest that low ethanol intake prevents adverse effects induced by a high-fat diet, such as lipid accumulation, cardiac dysfunction, hypertrophy and fibrosis. Furthermore, low ethanol intake upregulates Rgs5, which suggests it plays a role in cardiac remodeling and heart failure.