Effect of Tea Polyphenols on Lipid Oxidation of Nemipterus VirgatusSurimi Cake During Ice Storage

Surimi cake is a high value aquatic product. In this work, lipid oxidation and volatile compounds in Nemipterus virgatus surimi cake were investigated to evaluate the effectiveness of tea polyphenols in preventing or reducing lipid oxidation. Surimi cake was prepared in the presence or absence of 0.2% tea polyphenols, and was stored at 4 ℃ for 16 days. It was found that the peroxide value(POV) and thiobarbituric acid reactive substances(TBARS) values of the experimental groups(with 0.2% tea polyphenols) were much lower than those of the untreated surimi cake(p<0.05). In total, 52 compounds were presented in the volatiles of the surimi cake, such as ethanol, hexanal,(E,E)-2,4-decadienal, 2,3-octanedione, 2-hydroxy-propanamide, and 2,5-dimethyl-pyrazine. It indicated that tea polyphenols could reduce the amount of hexanal, ethanol, and(E,E)-2,4-decadienal, and delay the lipid oxidation of the surimi cake. Effects of lipid oxidation of the tea polyphenols on surimi cake were reduced during storage in ice.

Effect of sodium starch octenyl succinate-based Pickering emulsion on the physicochemical properties of hairtail myofibrillar protein gel subjected to multiple freeze-thaw cycles

A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.

Effects of cytokines and chemokines on migration of mesenchymal stem cells following spinal cord injury

We investigated the effects of cytokines and chemokines and their associated signaling pathways on mesenchymal stem cell migration after spinal cord injury, to determine their roles in the curative effects of mesenchymal stem cells. This study reviewed the effects of tumor necrosis factor-α, vascular endothelial growth factor, hepatocyte growth factor, platelet-derived growth factor, basic fibroblast growth factor, insulin like growth factor-I, stromal cell-derived factor and monocyte chemoattractant protein-1, 3 during mesenchymal stem cell migration to damaged sites, and analyzed the signal transduction pathways involved in their effects on mesenchymal stem cell migration. The results confirmed that phosphatidylinositol 3-kinase/serine/threonine protein kinases and nuclear factor-KB play crucial roles in the migration of mesenchymal stem cells induced by cytokines and chemokines.

Effects of Pendular Waist on Gecko＇s Climbing： Dynamic Gait, Analytical Model and Bio-inspired Robot

Most quadruped reptiles, such as lizards, salamanders and crocodiles, swing their waists while climbing on horizontal or vertical surfaces. Accompanied by body movement, the centroid trajectory also becomes more of a zigzag path rather than a straight line. Inspired by gecko＇s gait and posture on a vertical surface, a gecko inspired model with one pendular waist and four active axil legs, which is called GPL model, is proposed. Relationship between the waist position, dynamic gait, and driving forces on supporting feet is analyzed. As for waist trajectory planning, a singular line between the supporting feet is found and its effects on driving forces are discussed. Based on the GPL model, it is found that a sinusoidal waist trajectory, rather than a straight line, makes the driving forces on the supporting legs smaller. Also, a waist close to the pygal can reduce the driving forces compared to the one near middle vertebration, which is in accord with gecko＇s body bending in the process of climbing. The principles of configuration design and gait planning are proposed based on theoretical analyses. Finally, a bio-inspired robot DracoBot is developed and both of the driving force measurements and climbing experiments reinforce theoretical analysis and the rationality of gecko＇s dynamic gait.

Research on Gliding Aerodynamic Effect of Deformable Membrane Wing for a Robotic Flying Squirrel

Inspired by creatures with membrane to obtain ultra-high gliding ability, this paper presents a robotic flying squirrel （a novel gliding robot） characterized as membrane wing and active membrane deformation. For deep understanding of membrane wing and gliding mechanism from a robotic system perspective, a simplified blocking aerodynamic model of the deformable membrane wing and CFD simulation are finished. In addition, a physical prototype is developed and wind tunnel experiments are carried out. The results show that the proposed membrane wing is able to support the gliding action of the robot. Meanwhile, factors including geometry characteristics, material property and wind speed are considered in the experiments to investigate the aerodynamic effects of the deformable membrane wing deeply. As a typical characteristic of robotic flying squirrel, deformation modes of the membrane wing not only affect the gliding ability, but also directly determine the effects of the posture adjustment. Moreover, different deformation modes of membrane wing are illustrated to explore the possible effects of active membrane deformation on the gliding performance. The results indicate that the deformation modes have a significant impact on posture adjustment, which reinforces the rationality of flying squirrel＇s gliding strategy and provides valuable information on prototype optimal design and control strategy in the actual gliding process.

Research on Non Intrusive Intelligent Monitoring System for Elevator State

The current elevator status monitoring systems basically realize the monitoring of elevator status by collecting signals from the main board of the elevator.However it is costly and lacks universality,which also requires invasive installation.To address the above problems,a non-invasive intelligent monitoring method is proposed in this paper for elevator operation status.Themethod decomposes the acceleration signal into vertical and horizontal components,estimates the dynamics of the elevator using Kalman filter,performs vibration analysis on the horizontal components,establishes a baseline for normal operation,and automatically calibrates the sensors by combining the operating characteristics of the elevator.The traceless Kalman filter based on fused SLAM was performed to couple the sensor information and track the real-time position of the elevator.The effectiveness and robustness of the method are verified in actual operation,and the problem of elevator position error accumulation is basically solved without installing fiducials.The designed non-intrusive elevator status intelligent monitoring method is low-cost and universal,which is of practical significance for promoting on-demand elevator maintenance.

Modeling and Analysis of EEG Brain Network in High Altitude Task State

Long-term exposure to high altitude,low pressure and low oxygen will seriously threaten people’s cognitive function.To explore the changes in wholebrain network dynamics during brain activity in long-term high-altitude migrants,EEG signals from three subjects of 75 different altitudes were analyzed using the Stroop experimental paradigm and the network recombination prediction model.The sliding window method was used to explore the dynamic change process of the brain network.At the same time,the time period with significant difference between the brain networks of the altitude group was selected as the real response network to measure the model prediction accuracy.Then,according to different network prediction model rules,the weights of brain network 200 ms before stimulation were updated for each subject.Finally,the prediction model with the least difference between the prediction network and the real response network was selected for each subject.The experimental results showed that the prediction accuracy of the model reach 98.95%,and there is a significant difference in model selection between the elevation groups.It helps to understand the brain dynamics of healthy people,and reveals the abnormal changes in the brain networks of those who have stayed at high altitude for a long time,providing an important reference for the cognitive rehabilitation training of victims ex-posed at high altitude.