Psychophysiological responses during the microcycle with the start of the national championship: A case study of a volleyball team

The aim of the study was to monitoring psychophysiological responses among volleyball players in the microcycle with a high-performance competition game scheduled. Methods: Ten male athletes (26.6 ± 5.3 years) from an adult volleyball team participated in the study. The variables session Rating of Perceived Exertion (Session RPE), Total Quality of Recovery scale (TQR), Well-being questionnaire (WB), testosterone, cortisol, and testosterone/cortisol Ratio (T:C ratio) were evaluated during the microcycle before the game. Results: Differences were observed in the daily training load (F = 23.776; p < 0.001), TQR (F = 10.687; p < 0.001), WB (F = 6.736; p < 0.001), cortisol (F = 8.253; p < 0.001) and T:C ratio (F = 3.862; p = 0.01). Conclusion: The behavior of the variables fluctuated with factors such as training load, number of training days and time off, and due to the psychophysiological stress of the match. (AU)

Determination of creatinine in urine and blood serum human samples by CZE-UV using on-column internal standard injection.

Creatinine is a well-stablished biomarker for kidney malfunctions and for normalization parameter of urinary quantitative information. Recently, metabolic studies have been discovering other functionalities for creatinine tests in human urine and blood serum. In this work we present an enhanced capillary electrophoresis (CE) based protocol for determination of creatinine. CE is a high-throughput separation technique that have been getting attention through the last decades and might be considered to be adopted as an analytical instrumentation for clinical purposes. In the proposed method, we performed a short injection program with on-column addition of internal standard. Additionally, the method allows a simultaneous screening of non-proteinogenic amino acids that could be considered for metabolomics purposes. We design a pilot study that successfully estimated the creatinine value in 100 urine samples with (2.85 ± 1.78) mg dL-1 LOD; (8.24 ± 5.93) mg dL-1 LOQ and 82.4% accuracy. Considering that serum creatinine is also included in the clinical laboratory routines for estimated Glomerular Filtration Rate dosage, the method was complementary applied to 10 blood serum samples, which resulted in a model with (0.4 ± 0.2) mg dL-1 LOD; (2.0 ± 0.6) mg dL-1 LOQ and 83.8% of accuracy. All results were in agreement with reference values. The proposed method promotes a great analytical frequency and reproducibility with enhanced specificity compared with the ongoing protocol by Jaffe's reaction, thereby proving to be useful as an alternative for creatinine exams that might help complete a diagnosis of a series of health-related issues.