Augmented muscle deoxygenation during repeated sprint exercise with post-exercise blood flow restriction.

Blood flow restriction (BFR) during low-intensity exercise has been known to be a potent procedure to alter metabolic and oxygen environments in working muscles. Moreover, the use of BFR during inter-set rest periods of repeated sprint exercise has been recently suggested to be a potent procedure for improving training adaptations. The present study was designed to determine the effect of repeated sprint exercise with post-exercise BFR (BFR during rest periods between sprints) on muscle oxygenation in working muscles. Eleven healthy males performed two different conditions on different days: either repeated sprint exercise with BFR during rest periods between sets (BFR condition) or without BFR (CON condition). A repeated sprint exercise consisted of three sets of 3 × 6-s maximal sprints (pedaling) with 24s rest periods between sprints and 5 min rest periods between sets. In BFR condition, two min of BFR (100-120 mmHg) for both legs was conducted between sets. During the exercise, power output and arterial oxygen saturation (SpO2 ) were evaluated. Muscle oxygenation for the vastus lateralis muscle, exercise-induced changes in muscle blood flow, and muscle oxygen consumption were measured. During BFR between sets, BFR condition presented significantly higher deoxygenated hemoglobin + myoglobin (p < 0.01) and lower tissue saturation index (p < 0.01) than those in CON condition. However, exercise-induced blood lactate elevation and reduction of blood pH did not differ significantly between the conditions. Furthermore, power output throughout nine sprints did not differ significantly between the two conditions. In conclusion, repeated sprint exercise with post-exercise BFR augmented muscle deoxygenation and local hypoxia, without interfering power output.

Successful Reboot of High-Performance Sporting Activities by Japanese National Women's Handball Team in Tokyo, 2020 during the COVID-19 Pandemic: An Initiative Using the Japan Sports-Cyber Physical System (JS-CPS) of the Sports Research Innovation Project (SRIP).

The COVID-19 pandemic has negatively impacted sporting activities across the world. However, practical training strategies for athletes to reduce the risk of infection during the pandemic have not been definitively studied. The purpose of this report was to provide an overview of the challenges we encountered during the reboot of high-performance sporting activities of the Japanese national handball team during the 3rd wave of the COVID-19 pandemic in Tokyo, Japan. Twenty-nine Japanese national women's handball players and 24 staff participated in the study. To initiate the reboot of their first training camp after COVID-19 stay-home social policy, we conducted: web-based health-monitoring, SARS-CoV-2 screening with polymerase chain reaction (PCR) tests, real-time automated quantitative monitoring of social distancing on court using a moving image-based artificial intelligence (AI) algorithm, physical intensity evaluation with wearable heart rate (HR) and acceleration sensors, and a self-reported online questionnaire. The training camp was conducted successfully with no COVID-19 infections. The web-based health monitoring and the frequent PCR testing with short turnaround times contributed remarkably to early detection of athletes' health problems and to risk screening. During handball, AI-based on-court social-distance monitoring revealed key time-dependent spatial metrics to define player-to-player proximity. This information facilitated appropriate on- and off-game distancing behavior for teammates. Athletes regularly achieved around 80% of maximum HR during training, indicating anticipated improvements in achieving their physical intensities. Self-reported questionnaires related to the COVID management in the training camp revealed a sense of security among the athletes that allowed them to focus singularly on their training. The challenges discussed herein provided us considerable knowledge about creating and managing a safe environment for high-performing athletes in the COVID-19 pandemic via the Japan Sports-Cyber Physical System (JS-CPS) of the Sports Research Innovation Project (SRIP, Japan Sports Agency, Tokyo, Japan). This report is envisioned to provide informed decisions to coaches, trainers, policymakers from the sports federations in creating targeted, infection-free, sporting and training environments.

Effects of combined hot and hypoxic conditions on muscle blood flow and muscle oxygenation during repeated cycling sprints.

PURPOSE: The purpose of the present study was to determine muscle blood flow and muscle oxygenation during repeated-sprint exercise under combined hot and hypoxic conditions. METHODS: In a single-blind, cross-over research design, 11 active males performed three sets of 5 × 6-s maximal sprints with 30-s active recovery on a cycling ergometer under control (CON; 23 °C, 50% rH, 20.9% FiO2), normobaric hypoxic (HYP; 23 °C, 50% rH, 14.5% FiO2), or hot + normobaric hypoxic (HH; 35 °C, 50% rH, 14.5% FiO2) conditions. The vastus lateralis muscle blood flow after each set and muscle oxygenation during each sprint were evaluated using near-infrared spectroscopy methods. RESULTS: Despite similar repeated-sprint performance among the three conditions (peak and mean power outputs, percent decrement score), HH was associated with significantly higher muscle blood flow compared with CON after the first set (CON: 0.61 ± 0.10 mL/min/100 g; HYP: 0.81 ± 0.13 mL/min/100 g; HH: 0.99 ± 0.16 mL/min/100 g; P < 0.05). The tissue saturation index was significantly lower in HYP than in CON during the latter phase of the exercise (P < 0.05), but it did not differ between HH and CON. CONCLUSION: These findings suggest that a combination of normobaric hypoxia and heat stress partially facilitated the exercise-induced increase in local blood flow, but it did not enhance tissue desaturation.

Effects of Reduced Carbohydrate Intake after Sprint Exercise on Breath Acetone Level.

Assessment of breath acetone level may be an alternative procedure to evaluate change in fat metabolism. The purpose of the present study was to investigate the effect of insufficient carbohydrate (CHO) intake after sprint exercise on breath acetone level during post-exercise. Nine subjects conducted two trials, consisting of either reduced CHO trial (LOW trial) or normal CHO trial (NOR trial). In each trial, subjects visited to laboratory at 7:30 following an overnight fast to assess baseline breath acetone level. They commenced repeated sprint exercise from 17:00. After exercise, isoenergetic meals with different doses of CHO (LOW trial; 18% for CHO, 27% for protein, 55% for fat, NOR trial; 58% for CHO, 14% for protein, 28% for fat) were served. Breath acetone level was also monitored immediately before and after exercise, 1 h, 3 h, 4 h, and 15 h (on the following morning) after completing exercise. A significant higher breath acetone level was observed in LOW trial than in NOR trial 4 h after completion of exercise (NOR trial; 0.66 ppm, LOW trial; 0.9 ppm). However, breath acetone level did not differ on the following morning between two trials. Therefore, CHO intake following an exhaustive exercise affects breath acetone level during early phase of post-exercise.

Utilisation of polarity inversion for phosphorus recovery in electrochemical precipitation with anaerobic digestion effluent.

Phosphorus is a non-replaceable and limited resource, whose future drought is a matter of concern. Its recovery from wastewater has gained attention as a method of making the recovered phosphorus available for beneficial use. This study applied electrolysis with a platinum-coated titanium electrode to an actual anaerobic digestion effluent and investigated the phosphorus removal and precipitation characteristics with various current values. The separation of the phosphorus precipitate from the sludge residue and the usefulness of the polarity inversion to recover the phosphorus precipitate were evaluated. The availability of the recovered precipitate as a fertiliser was also demonstrated. The anaerobic digestion effluent after the centrifugal dehydration process with a coagulant was collected from a wastewater treatment plant. Phosphorus was precipitated as a form of calcium phosphate, including hydroxyapatite, which was confirmed by X-ray diffraction. The generated gases from the electrodes during the electrolysis floated and condensed the sludge residue, leading to successful separation of the phosphorus precipitate from the sludge residue. The polarity inversion successfully detached the phosphorus precipitate from the electrode, and at least 3 min polarity inversion was enough to detach the whole phosphorus precipitate. The submerging phosphorus precipitate contained abundant phosphorus (12.6%), in which citric-acid-soluble phosphorus accounted for 94.4%, and the utilisation of the precipitate as a slow-release phosphorus fertiliser was suggested.

Brain-computer interface with somatosensory feedback improves functional recovery from severe hemiplegia due to chronic stroke.

Recent studies have shown that scalp electroencephalogram (EEG) based brain-computer interface (BCI) has a great potential for motor rehabilitation in stroke patients with severe hemiplegia. However, key elements in BCI architecture for functional recovery has yet to be clear. We in this study focused on the type of feedback to the patients, which is given contingently to their motor-related EEG in a BCI context. The efficacy of visual and somatosensory feedbacks was compared by a two-group study with the chronic stroke patients who are suffering with severe motor hemiplegia. Twelve patients were asked an attempt of finger opening in the affected side repeatedly, and the event-related desynchronization (ERD) in EEG of alpha and beta rhythms was monitored over bilateral parietal regions. Six patients were received a simple visual feedback in which the hand open/grasp picture on screen was animated at eye level, following significant ERD. Six patients were received a somatosensory feedback in which the motor-driven orthosis was triggered to extend the paralyzed fingers from 90 to 50°. All the participants received 1-h BCI treatment with 12-20 training days. After the training period, while no changes in clinical scores and electromyographic (EMG) activity were observed in visual feedback group after training, voluntary EMG activity was newly observed in the affected finger extensors in four cases and the clinical score of upper limb function in the affected side was also improved in three participants in somatosensory feedback group. Although the present study was conducted with a limited number of patients, these results imply that BCI training with somatosensory feedback could be more effective for rehabilitation than with visual feedback. This pilot trial positively encouraged further clinical BCI research using a controlled design.

Progress of the conversion reaction of Mn3O4 particles as a function of the depth of discharge.

A comprehensive investigation of the morphological and interfacial changes of Mn3O4 particles at different lithiation stages was performed in order to improve our understanding of the mechanism of the irreversible conversion reaction of Mn3O4. The micronization of Mn3O4 into a Mn-Li2O nanocomposite microstructure and the formation of a solid electrolyte interphase (SEI) on the Mn3O4 surface were carefully observed and characterized by combining high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and in situ X-ray absorption fine structure (XAFS) measurements. Accumulation of a thin SEI film of 2-5 nm thickness on the surfaces of the Mn3O4 particles due to their catalytic decomposition was observed at a depth of discharge (DOD) of 0%. As the DOD increases from 25% to 75%, the SEI layer composed of Li2CO3 and LiF continues to grow to 20-30 nm, and Li2O nanoparticles are clearly observed. At 100% DOD, the Mn-Li2O particles with diameters of 2-5 nm become totally encapsulated within a huge organic-inorganic coating structure, while the overall starting shape of the particles remains.

Effects of neurofeedback training with an electroencephalogram-based brain-computer interface for hand paralysis in patients with chronic stroke: a preliminary case series study.

OBJECTIVE: To explore the effectiveness of neurorehabilitative training using an electroencephalogram-based brain- computer interface for hand paralysis following stroke. DESIGN: A case series study. SUBJECTS: Eight outpatients with chronic stroke demonstrating moderate to severe hemiparesis. METHODS: Based on analysis of volitionally decreased amplitudes of sensory motor rhythm during motor imagery involving extending the affected fingers, real-time visual feedback was provided. After successful motor imagery, a mechanical orthosis partially extended the fingers. Brain-computer interface interventions were carried out once or twice a week for a period of 4-7 months, and clinical and neurophysiological examinations pre- and post-intervention were compared. RESULTS: New voluntary electromyographic activity was measured in the affected finger extensors in 4 cases who had little or no muscle activity before the training, and the other participants exhibited improvement in finger function. Significantly greater suppression of the sensory motor rhythm over both hemispheres was observed during motor imagery. Transcranial magnetic stimulation showed increased cortical excitability in the damaged hemisphere. Success rates of brain-computer interface training tended to increase as the session progressed in 4 cases. CONCLUSION: Brain-computer interface training appears to have yielded some improvement in motor function and brain plasticity. Further controlled research is needed to clarify the role of the brain-computer interface system.