Background Mental fatigue is usually caused by long-term cognitive activities, mainly manifested as drowsiness, difficulty in concentrating, decreased alertness, disordered thinking, slow reaction, lethargy, reduced work efficiency, error-prone and so on. Mental fatigue has become a widespread sub-health condition, and has a serious impact on the cognitive function of the brain. However, seldom studies investigate the differences of mental fatigue on electrophysiological activity both in resting state and task state at the same time. Here, twenty healthy male participants were recruited to do a consecutive mental arithmetic tasks for mental fatigue induction, and electroencephalogram (EEG) data were collected before and after each tasks. The power and relative power of five EEG rhythms both in resting state and task state were analyzed statistically. Results The results of brain topographies and statistical analysis indicated that mental arithmetic task can successfully induce mental fatigue in the enrolled subjects. The relative power index was more sensitive than the power index in response to mental fatigue, and the relative power for assessing mental fatigue was better in resting state than in task state. Furthermore, we found that it is of great physiological significance to divide alpha frequency band into alpha1 band and alpha2 band in fatigue related studies, and at the same time improve the statistical differences of sub-bands. Conclusions Our current results suggested that the brain activity in mental fatigue state has great differences in resting state and task state, and it is imperative to select the appropriate state in EEG data acquisition and divide alpha band into alpha1 and alpha2 bands in mental fatigue related researches.

Degradation of meat quality has always been a burning issue in fish preservation. To maintain the quality, a novel combination of chlorogenic acid (CGA) and chitosan (CS) coating was applied to snakehead fish fillets. Fish fillets were soaked into 2% chitosan (2CS), 0.2% CGA in 2% chitosan (0.2CGA/2CS), 0.5% CGA in 2% chitosan (0.5CGA/2CS), or 1.0% CGA in 2% chitosan (1.0CGA/2CS) solution; and then, coated samples were vacuum‐packaged and stored at 2 ± 0.5°C. pH values, color values, microbial loads, hardness, sensory qualities, and oxidization of lipids and proteins of stored fish fillets were investigated for 5 months. Antimicrobial activity was found to be nonsignificant (p ≤ .05) among different coated fish fillets, while color, antioxidant, and pH values were significantly (p ≤ .05) different. Lipid oxidation and protein oxidation were found to be inhibited in 2CS‐, 0.5CGA/2CS‐ and 1.0CGA/2CS‐coated fish fillet. All CGA/CS coating delayed increase in pH (p ≤ .05) and resulted brown color. However, only CS coating resulted in higher sensory scores (p ≤ .05) and controlled browning. Considering antioxidant properties and other quality parameters, CGA/CS coating might be applied commercially in fish preservation.

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