Determinación de agua en alcoholes usando como reactivo un tiocianocomplejo del cobalto

En el presente trabajo se propone un método cuantitativopara la determinación de agua en etanol, basado en las variaciones de intensidad del color azul que presentan las soluciones hidroalcohólicas del complejo tetratiocianocobaltato(II) de potasio.El compuesto de coordinación se prepara triturando intimamente en un mortero cantidades estequiométricas desulfato de cobalto(II) y tiocianato de potasio. El complejoobtenido se extrae con etanol, y el sulfato de potasioremanente es insoluble en este medio. El extracto alcohólicofiltrado se evapora lentamente y los cristales azulesobtenidos se mantienen en desecador conteniendo ácido sulfúrico.El objetivo del presente trabajo es desarrollar un métodocuantitativo usando la espectrofotometría molecular, para determinar la concentración de agua en alcoholes hidratados.Esta técnica es de aplicación a limitadas cantidades de agua en alcohol etílico (3,6 -11,2 %) pues a mayores concentracionesde agua en la solución complejo-etanol, se descompone el complejo, liberando el ión cobalto(II) que colorea de rosado la solución

The Relationship Between Lactate and Ventilatory Thresholds in Runners: Validity and Reliability of Exercise Test Performance Parameters

The aims of this study were (1) to establish the best fit between ventilatory and lactate exercise performance parameters in running and (2) to explore novel alternatives to estimate the maximal aerobic speed (MAS) in well-trained runners. Twenty-two trained male athletes (V˙O2max 60.2 ± 4.3 ml·kg·min−1) completed three maximal graded exercise tests (GXT): (1) a preliminary GXT to determine individuals' MAS; (2) two experimental GXT individually adjusted by MAS to record the speed associated to the main aerobic–anaerobic transition events measured by indirect calorimetry and capillary blood lactate (CBL). Athletes also performed several 30 min constant running tests to determine the maximal lactate steady state (MLSS). Reliability analysis revealed low CV (<3.1%), low bias (<0.5 km·h−1), and high correlation (ICC > 0.91) for all determinations except V-Slope (ICC = 0.84). Validity analysis showed that LT, LT+1.0, and LT+3.0 mMol·L−1 were solid predictors of VT1 (−0.3 km·h−1; bias = 1.2; ICC = 0.90; p = 0.57), MLSS (−0.2 km·h−1; bias = 1.2; ICC = 0.84; p = 0.74), and VT2 (<0.1 km·h−1; bias = 1.3; ICC = 0.82; p = 0.9l9), respectively. MLSS was identified as a different physiological event and a midpoint between VT1 (bias = −2.0 km·h−1) and VT2 (bias = 2.3 km·h−1). MAS was accurately estimated (SEM ± 0.3 km·h−1) from peak velocity (Vpeak) attained during GXT with the equation: MASEST (km·h−1) = Vpeak (km·h−1) * 0.8348 + 2.308. Current individualized GXT protocol based on individuals' MAS was solid to determine both maximal and submaximal physiological parameters. Lactate threshold tests can be a valid and reliable alternative to VT and MLSS to identify the workloads at the transition from aerobic to anaerobic metabolism in well-trained runners. In contrast with traditional assumption, the MLSS constituted a midpoint physiological event between VT1 and VT2 in runners. The Vpeak stands out as a powerful predictor of MAS

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Herramienta para el control de la técnica de nado en mariposa

Hoja de cálculo que permite realizar una análisis técnico del nado de espalda mediante observación directa o análisis de vídeo

Etapas del Desarrollo en los LTAD

En este documento se resumen las principales características de cada una de las etapas fundamentales de los programa de desarrollo a largo plazo. Con ello el alumnado puede sensibilizarse hacia las necesidades y la realidad propia de cada etapa del desarrollo físico, emocional y deportivo

Radiografía del Deporte. Triatlón Olímpico

Material docente en el que el alumnado puede ver de forma gráfica el análisis competitivo de una modalidad deportiva. En este caso, el triatlón Olímpico

Adaptation of training methods to the peculiarities of swimming

La natación tiene unas circunstancias especiales a la hora de entrenar y monitorizar la actividad física que se lleva a cabo. Esto ha hecho que a lo largo del tiempo hayan surgido investigaciones y recursos que nos permitan controlar el proceso de entrenamiento de manera efectiva con alternativas a las variables clásicas. Además, el comportamiento fisiológico en el medio acuático varía respecto al ejercicio físico fuera de él, lo que también hace que sean necesarias algunas adaptaciones metodológicas. Actualmente la natación es un deporte creciente por su gran importancia dentro del triatlón, y las nuevas tecnologías también han logrado ofrecernos nuevas vías para el entendimiento y control del proceso formativo y de entrenamiento. El correcto manejo de las variables que determinan la carga de entrenamiento es la clave para conseguir las adaptaciones que nos aporten una mejora o nos ayude a contrarrestar los factores limitantes del rendimiento. Este trabajo muestra las principales modificaciones que requiere la programación del volumen, intensidad y densidad del entrenamiento en el medio acuáticoABSTRACT: The swimming has special circumstances when it comes to train and monitor physical activity. This has meant that over time have arisen research and resources that enable us to control the training process effectively with alternatives to the classic variables. In addition, the physiological behaviour in the acuatic environment varies from the exercise out of it, which also makes some methodological adaptations are necessary. Currently swimming is a growing sport for its great importance in the triathlon, and new technologies have also managed to offer new avenues for understanding and control of the training process and training. The correct handling of the variables that determine the training load is the key to the adaptations that bring us a better or help us counter the limiting factors of performance. This paper shows the main changes required volume programming, training intensity and density in the aquatic environmen