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AbstractPlantaginis Semen (PS) are the dried mature seeds of Plantago asiatica L. or Plantagodepressa Willd. in the Plantago family. Its polysaccharides are important components of PS. Response surface methodology was used to optimize the ultrasonic-assisted deep eutectic solvent (DES) extraction process of PS polysaccharides (PSP). The results showed that the optimal extraction parameters were a solid-liquid ratio of 1:35 g/mL, an extraction time of 73 min, and a molar ratio of 2:1. The yield of PSP was 0.64% and 1.20% by water immersion and ultrasonic water extraction, respectively, indicating that the DES extraction method (2.21 ± 0.06%) is superior to these two methods, and the optimization effect is good. Through the α-glucosidase and α-amylase inhibition activities experiment, it was found that the IC50 values of PSPs-1 were 1122 and 220.5 μg/mL. DPPH·and ABTS+ scavenging activity experiments showed that the IC50 values of PSPs-1 were 19.2 and 4.3 μg/mL, respectively. Its molar ratio of monosaccharide composition is rhamnose: galactose: galacturonic acid: glucose: glucuronic acid: arabinose: mannose: xylose = 33.6:13.3:6.5:3:2.6:2:1.4:1. Therefore, this study can provide an experimental basis for the establishment of an industrialized production process of polysaccharides and the study of their biological activities. [ABSTRACT FROM AUTHOR]

In this work, through integrate that teaching management system, the learn mode of the O2O is used to build a learner‐centered frame of the teaching reformation. This frame is supported by the O2O learning platform, with themed practical teaching and O2O model as the main body, and the "Thousand questions plan" and "Teachers guiding" system as two guarantee supports. In order to achieve high quality results, specific implementation plan, including management system and implementation measures has been formulated in teaching reform of O2O platform. The questionnaire shows that this system has mobilized the enthusiasm of teachers and students. By comparing the practice results of the experimental class and the control class, the effectiveness of the O2O teaching framework is verified, and the teaching reform is successful. Finally, this paper provides teaching inspiration and future research direction for educators and researchers. [ABSTRACT FROM AUTHOR]

The threshold pressure to induce cavitation in supercritical carbon dioxide is analysed with Rayleigh theory, and the surface tension and the viscosity of the fluid are ignored. It is found that the acquired ultrasonic pressure is similar to the critical pressure of the fluid due to the absence of vapour pressure. Based on a liquid state equation and the available physical parameters, a new state equation for supercritical carbon dioxide is proposed for solving the Gilmore equation with improved accuracy. The fourth order Runge–Kutta method is adopted to calculate the bubble-wall motions and the results show that a bubble in supercritical carbon dioxide may collapse and the characteristics of its motion are similar to cavitations in ordinary liquid. The compressibility of supercritical fluid should be considered when studying its cavitations, and our results show that the collapse intensity decreases greatly when the compressibility of supercritical fluid is considered. [ABSTRACT FROM AUTHOR]