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Metal oxide sensor‐based electronic nose (E‐Nose) technology provides an easy to use method for breath analysis by detection of volatile organic compound (VOC)‐induced changes of electrical conductivity. Resulting signal patterns are then analyzed by machine learning (ML) algorithms. This study aimed to establish breath analysis by E‐Nose technology as a diagnostic tool for severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) pneumonia within a multi‐analyst experiment. Breath samples of 126 subjects with (n = 63) or without SARS‐CoV‐2 pneumonia (n = 63) were collected using the ReCIVA® Breath Sampler, enriched and stored on Tenax sorption tubes, and analyzed using an E‐Nose unit with 10 sensors. ML approaches were applied by three independent data analyst teams and included a wide range of classifiers, hyperparameters, training modes, and subsets of training data. Within the multi‐analyst experiment, all teams successfully classified individuals as infected or uninfected with an averaged area under the curve (AUC) larger than 90% and misclassification error lower than 19%, and identified the same sensor as most relevant to classification success. This new method using VOC enrichment and E‐Nose analysis combined with ML can yield results similar to polymerase chain reaction (PCR) detection and superior to point‐of‐care (POC) antigen testing. Reducing the sensor set to the most relevant sensor may prove interesting for developing targeted POC testing. [ABSTRACT FROM AUTHOR]

Background: Volleyball is a complex intermittent sport characterized by short explosive technical movements, many of which involve vertical jumping. The assessment of mechanical jumping variables in relation to both injury prevention and performance enhancement through the use of wearable technologies is becoming a new training tool among professional volleyball players., Methods: The present study aimed to assess the vertical jumping mechanics before and after a controlled load (volume and intensity) of a routine volleyball training session among male professional players. Twelve male elite professional volleyball players (23.7±4.9 years, 198.1±6.2 cm, 92.2±10.3 kg) of national and international level belonging to the same Brazilian first league team were recruited. Biomechanical analysis of vertical unilateral countermovement jump (CMJ) and bilateral CMJ tests were performed before and after a routine training session of these players at their usual training court. An inertial orientation sensor placed at the third lumbar vertebra was employed for biomechanical data collection., Results: In relation to the unilateral CMJ, a 10% decrease (P=0.02) in the vertical ground reaction force after training compared to pretraining values was observed. However, no significant differences were observed in the remaining outcomes. Regarding the bilateral CMJ, no significant differences were observed in all assessed outcomes., Conclusions: Our findings showed no evidence of fatigue after a controlled regular in season volleyball training session in professional players. In addition, this volleyball training session induced a significant reduction in the vertical ground reaction force during unilateral CMJ in volleyball players.