Sliding mode observer-based model predictive tracking control for Mecanum-wheeled mobile robot.

This paper proposes a novel adaptive variable power sliding mode observer-based model predictive control (AVPSMO-MPC) method for the trajectory tracking of a Mecanum-wheeled mobile robot (MWMR) with external disturbances and model uncertainties. First, in the absence of disturbances and uncertainties, a model predictive controller that considers various physical constraints is designed based on the nominal dynamics model of the MWMR, which can transform the tracking problem into a constrained quadratic programming (QP) problem to solve the optimal control inputs online. Subsequently, to improve the anti-jamming ability of the MWMR, an AVPSMO is designed as a feedforward compensation controller to suppress the effects of external disturbances and model uncertainties during the actual motion of the MWMR, and the stability of the AVPSMO is proved via Lyapunov theory. The proposed AVPSMO-MPC method can achieve precise tracking control while ensuring that the constraints of MWMR are not violated in the presence of disturbances and uncertainties. Finally, comparative simulation cases are presented to demonstrate the effectiveness and robustness of the proposed method.

Using untargeted metabolomics to profile the differences of the fruits of Lycium barbarum in different geographical origins.

An ultra-high performance liquid chromatography system coupled with the Q-Exactive mass spectrometry (UHPLC-QE-MS) approach combined with multivariate statistical analysis was used to investigate the metabolic profiles of the fruits of Lycium barbarum in different geographical origins in China. Several classes of compounds such as sugars, amino acids, organic acids, fatty acids, polyphenols and alkaloid were identified in hydroalcoholic extracts, and ten differential metabolites including amino acids, organic acids and vitamins were identified by multivariate statistical method. It was discussed that the differences between organic acids and amino acids in the samples may be caused by environmental factors such as ultraviolet radiation, soil and altitude. A total of 119 metabolic pathways were involved in the differential metabolites and 17 of them were retained for enrichment analysis. It was found that alanine, aspartate and glutamate metabolism, arginine biosynthesis, glutathione metabolism, glyoxylate and dicarboxylate metabolism, purine metabolism, histidine metabolism and aminoacyl-tRNA biosynthesis were the most important pathways. These findings play an important role in the origin tracing of the Lycium barbarum fruit.

Metabolomics coupled with similarity analysis advances the elucidation of the cold/hot properties of traditional Chinese medicines.

It recently becomes an important and urgent mission for modern scientific research to identify and explain the theory of traditional Chinese medicine (TCM), which has been utilized in China for more than four millennia. Since few works have been contributed to understanding the TCM theory, the mechanism of actions of drugs with cold/hot properties remains unclear. In the present study, six kinds of typical herbs with cold or hot properties were orally administered into mice, and serum and liver samples were analyzed using an untargeted nuclear magnetic resonance (NMR) based metabolomics approach coupled with similarity analysis. This approach was performed to identify and quantify changes in metabolic pathways to elucidate drug actions on the treated mice. Our results showed that those drugs with same property exerted similar effects on the metabolic alterations in mouse serum and liver samples, while drugs with different property showed different effects. The effects of herbal medicines with cold/hot properties were exerted by regulating the pathways linked to glycometabolism, lipid metabolism, amino acids metabolism and other metabolic pathways. The results elucidated the differences and similarities of drugs with cold/hot properties, providing useful information on the explanation of medicinal properties of these TCMs.

[~1H NMR fingerprints of Huangqi injection solution].

The study established the 1H NMR-based fingerprinting and analyzed 8 batches of Huangqi injection solution.1H NMR-based fingerprinting of both primary and secondary metabolites of Huangqi injection were established, and the 1H-1H chemical shift correlation spectroscopy (COSY) and 1H-13C chemical shift correlation spectroscopy (HSQC) were used to identify the chemical components in Huangqi injection solution. Coupled with similarity analysis and relative content determination,8 batches of Huangqi injection solution were analyzed. Twenty-five metabolites (both primary and secondary) were identified, and the significant differences were found in the chemical composition among these Huangqi samples. The content and content variation of the primary metabolites were much higher than those of the secondary metabolites, which was the major cause of the uniformity of the Huangqi injections. The results on the quality variations of Huangqi injections in this study will serve as a basis for improving the quality control.

Echinacoside induces rat pulmonary artery vasorelaxation by opening the NO-cGMP-PKG-BKCa channels and reducing intracellular Ca2+ levels.

AIM: Sustained pulmonary vasoconstriction as experienced at high altitude can lead to pulmonary hypertension (PH). The main purpose of this study is to investigate the vasorelaxant effect of echinacoside (ECH), a phenylethanoid glycoside from the Tibetan herb Lagotis brevituba Maxim and Cistanche tubulosa, on the pulmonary artery and its potential mechanism. METHODS: Pulmonary arterial rings obtained from male Wistar rats were suspended in organ chambers filled with Krebs-Henseleit solution, and isometric tension was measured using a force transducer. Intracellular Ca(2+) levels were measured in cultured rat pulmonary arterial smooth muscle cells (PASMCs) using Fluo 4-AM. RESULTS: ECH (30-300 µmol/L) relaxed rat pulmonary arteries precontracted by noradrenaline (NE) in a concentration-dependent manner, and this effect could be observed in both intact endothelium and endothelium-denuded rings, but with a significantly lower maximum response and a higher EC50 in endothelium-denuded rings. This effect was significantly blocked by L-NAME, TEA, and BaCl2. However, IMT, 4-AP, and Gli did not inhibit ECH-induced relaxation. Under extracellular Ca(2+)-free conditions, the maximum contraction was reduced to 24.54%±2.97% and 10.60%±2.07% in rings treated with 100 and 300 µmol/L of ECH, respectively. Under extracellular calcium influx conditions, the maximum contraction was reduced to 112.42%±7.30%, 100.29%±8.66%, and 74.74%±4.95% in rings treated with 30, 100, and 300 µmol/L of ECH, respectively. After cells were loaded with Fluo 4-AM, the mean fluorescence intensity was lower in cells treated with ECH (100 µmol/L) than with NE. CONCLUSION: ECH suppresses NE-induced contraction of rat pulmonary artery via reducing intracellular Ca(2+) levels, and induces its relaxation through the NO-cGMP pathway and opening of K(+) channels (BKCa and KIR).