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This paper aimed to investigate the antioxidant activity of buckwheat bee pollen polysaccharides (BWPP) during the in vitro gastrointestinal digestion. The crude polysaccharides were purified using DEAE-52 cellulose column and their antioxidant activity during in vitro simulated gastric and intestinal digestion was studied. The results showed that after purification by DEAE-52 cellulose column chromatography, the highest total sugar content component BWPP-1 was obtained, which was mainly composed of Glc, Xyl, Ara, etc. The infrared spectrum showed that BWPP-1 had obvious polysaccharide characteristic absorption peaks. During the simulated in vitro gastrointestinal digestion, the ABTS+· scavenging rates of BWPP and BWPP-1 reached their maximum values at 60 minutes of simulated gastric juice digestion, which were 86.39%±1.28% and 90.38%±2.78%, respectively. There was a significant difference compared to other digestion times (P<0.05). The DPPH· clearance rates reached their maximum values at 60 minutes, which were 86.86%±0.11% and 89.58%±1.67%, respectively, and the difference between the two was not significant (P>0.05). When simulating intestinal digestion, the maximum clearance rates of ABTS+· by BWPP and BWPP-1 reached 88.67%±0.40% and 91.82%±2.77% at 60 minutes, and the difference between the two was not significant (P>0.05). The DPPH· scavenging rates reached their peak values at 240 minutes of 57.11%±0.06% and 65.67%±3.67%, with significant difference (P<0.05). During the digestion process, the ability to reduce iron ions was relatively weak. Based on these findings, it can be concluded that BWPP and BWPP-1 have good ABTS+· and DPPH· scavenging abilities, and the DPPH· scavenging ability during gastric digestion is slightly higher than that during intestinal digestion, while the ABTS+· scavenging ability during intestinal digestion is slightly higher than that during gastric digestion. This study provides a theoretical basis for the development of functional products based on buckwheat bee pollen. [ABSTRACT FROM AUTHOR]

How to improve our episodic memory is an important issue in the field of memory. In the present study, we used a discriminative learning paradigm that was similar to a paradigm used in animal studies. In Experiment 1, a picture (e.g., a dog) was either paired with an identical picture, with a similar picture of the same concept (e.g., another dog), or with a picture of a different concept (e.g., a cat). Then, after intervals of 10 min, 1 d, and 1 wk, participants were asked to perform a 2-alternative forcedchoice (2AFC) task to discriminate between a repeated and a similar picture, followed by the contextual judgment. In Experiment 2, eye movements were measured when participants encoded the pairs of pictures. The results showed that by discriminative learning, there was better memory performance in the 2AFC task for the "same" and "similar" conditions than for the "different" condition. In addition, there was better contextual memory performance for the "similar" condition than for the other two conditions.With regard to the eye movements, the participants were more likely to fixate on the lure objects and mademore saccades between the target and lure objects in the "similar" (versus "different") condition. The number of saccades predicted how well the targets were remembered in both the 2AFC and contextual memory tasks. These results suggested that with discriminative learning of similar objects, detailed information could be better encoded by distinguishing the object from similar interferences, making the details and the contexts better remembered and retained over time.

A periodic mass-spring-truss chain based on a scissor-like structure and inertial amplification is proposed to seek for low-frequency vibration attenuation. The resonant and anti-resonant frequencies of a basic element are obtained analytically to explain the resonance and anti-resonance of the periodic chain. The formation of bandgaps is explored, revealing that the vertical movements of the vertices take the input kinetic energy away from the horizontal movement energy. The cut-off frequencies of three models are derived analytically to compare the effect of the inertia amplification, which can reach more than three times the classical mass-spring chain with a small angle. Also, the effect of stiffness amplification is presented when the spring mounted vertically, unlike the classical inertial amplification systems. Thus, the optimal configuration for low-frequency attenuation is obtained, that is, the spring mounted horizontally and the masses mounted at the upper and lower vertices. The chain with mass on the upper and lower vertices has the lowest cut-off frequency, which is 17.7% lower than that of the classical mass-spring chain. A diatomic chain is studied to find lower and wider bandgaps, where the central frequency is 25% lower than the classical mass-spring diatomic chain. The central frequency and width of the new bandgap can be tunable accordingly. The result shows that small angles or low stiffness ratios result in lower bandgaps. Meanwhile, the large angles, big differences of masses, or high stiffness ratios lead to wider bandgaps. [ABSTRACT FROM AUTHOR]