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• Muscle synergies and muscle networks were extracted from three distinct frequency components (20–450 Hz, 20–30 Hz, 30–450 Hz). • The low-frequency component (20–30 Hz) is capable of performing muscle synergy analysis as done in the full-band (20–450 Hz). • Alterations in muscle coordination induced by stroke are evident in the full-band in muscle network analysis. As a neural control strategy employed by the central nervous system to control movements, the extraction of muscle synergies from a broad range of electromyographic signals has been the focus. Nevertheless, recent coherence analysis demonstrates distinct roles played in low-frequency components in motor control. This suggests that muscle synergies extracted from the low-frequency components can capture movement characteristics as done in the full-band. To investigate this issue, muscle synergies were extracted from three distinct frequency components (20–450 Hz, 20–30 Hz, 30–450 Hz) during spatial reaching movements in a group of healthy and stroke subjects. Synergy similarities were computed both within frequencies and between groups, and complex network analysis was conducted based on the group-averaged synergies. Results showed that the number and structure of muscle synergies, as well as network metrics, identified from the full-band (20–450 Hz) and low-frequency (20–30 Hz) exhibited high similarity between groups. These patterns diverged from those observed in high-frequency (30–450 Hz). The stroke did not induce significant alterations in muscle synergies. However, higher network metrics were identified in the full-band for one synergy. This study demonstrated the capacity of low-frequency components to perform muscle synergy analysis. These findings can help better understand the neural drive and motor control, potentially advancing the assessment of motor function and rehabilitation strategies. [ABSTRACT FROM AUTHOR]

Herein, sludge-derived biochar (BS) as an effective peroxymonosulfate (PMS) activator (BS900) was prepared by a simple one-step pyrolysis treatment. The BS900 demonstrated remarkable capability in activating PMS for efficient tetracycline (TC) removal. The existence of zero-valent iron (Fe0), the elevated ratio of Fe2+ to Fe3+, and the elevated percentage content of graphitic N were identified as the main contributors to the high PMS activation performance of BS900. Correspondingly, compared with other BS-derived PMS activators, the lowest charge transfer resistance (R ct) of BS900 was obtained, indicating efficient charge transfer between the PMS molecule and BS900. The generated reactive oxygen species (ROS) including the superoxide radical (O 2 •-) and singlet oxygen (1O 2) were verified by the radical trapping and electron paramagnetic resonance (EPR) tests during the BS-induced PMS activation process. The generated O 2 •- served as the precursor for 1O 2 formation. Whereas, the yields of the OH• and SO 4 •- were inhibited, suggesting that PMS activation by BS900 was a process dominated by ROS. Furthermore, the evaluation of ecotoxicity showed the TC degradation intermediates exhibit lower developmental toxicity and no mutagenicity. The research offers a novel perspective into the characteristics and mechanism of PMS-based advanced oxidation processes (AOPs) catalyzed by sludge-derived biochar. [Display omitted] • Biochar derived from the sludge (BS900) was prepared by one-step pyrolysis treatment • BS900 illustrated high ability to activate PMS for the removal of tetracycline (TC) • O 2 •- and 1O 2 were generated during the BS-induced PMS activation process • PMS activation by BS900 was a process dominated by reactive oxygen species (ROS) • O 2 •- was the indispensable precursor for 1O 2 formation [ABSTRACT FROM AUTHOR]