Measuring the solubility product constant of paramagnetic cations using time-domain nuclear magnetic resonance relaxometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exercise tolerance can be enhanced through a change in work rate within the severe intensity domain: work above critical power is not constant

The characterization of the hyperbolic power-time (P-tlim) relationship using a two-parameter model implies that exercise tolerance above the asymptote (Critical Power; CP), i.e. within the severe intensity domain, is determined by the curvature (W') of the relationship. The purposes of this study were (1) to test whether the amount of work above CP (W>CP) remains constant for varied work rate experiments of high volatility change and (2) to ascertain whether W' determines exercise tolerance within the severe intensity domain. Following estimation of CP (208 ± 19 W) and W' (21.4 ± 4.2 kJ), 14 male participants (age: 26 ± 3; peak [Formula: see text]: 3708 ± 389 ml.min-1) performed two experimental trials where the work rate was initially set to exhaust 70% of W' in 3 ('THREE') or 10 minutes ('TEN') before being subsequently dropped to CP plus 10 W. W>CP for TEN (104 ± 22% W') and W' were not significantly different (P>0.05) but lower than W>CP for THREE (119 ± 17% W', P<0.05). For both THREE (r = 0.71, P<0.01) and TEN (r = 0.64, P<0.01), a significant bivariate correlation was found between W' and tlim. W>CP and tlim can be greater than predicted by the P-tlim relationship when a decrement in the work rate of high-volatility is applied. Exercise tolerance can be enhanced through a change in work rate within the severe intensity domain. W>CP is not constant.

Comparison of frequency and time domain electromyography parameters in women with patellofemoral pain

Despite its high incidence, patellofemoral pain etiology remains unclear. No prior study has compared surface electromyography frequency domain parameters and surface electromyography time domain variables, which have been used as a classic analysis of patellofemoral pain. Thirty one women with patellofemoral pain and twenty eight pain-free women were recruited. Each participant was asked to descend a seven step staircase and data from five successful trials were collected. During the task, the vastus medialis and vastus lateralis muscle activities were monitored by surface electromyography. The data were processed and analyzed in four variables of the frequency domain (median frequency, low, medium and high frequency bands) and three time domain variables (Automatic, Cross-correlation and Visual Onset between the vastus medialis and vastus lateralis muscles). Reliability, Receiver Operating Characteristic curves and regression models were performed. The medium frequency band was the most reliable variable and different between the groups for both muscles, also demonstrated the best values of sensitivity and sensibility, 72% and 69% for the vastus medialis and 68% and 62% for the vastus lateralis, respectively. The frequency variables predicted the pain of individuals with patellofemoral pain, 26% for the vastus medialis and 20% for the vastus lateralis, being better than the time variables, which achieved only 7%. The frequency domain parameters presented greater reliability, diagnostic accuracy and capacity to predict pain than the time domain variables during stair descent and might be a useful tool to diagnose individuals with patellofemoral pain.

Accumulation of domain-specific physical inactivity and presence of hypertension in brazilian public healthcare system

Hypertension is one of the most common noncommunicable diseases worldwide, and physical inactivity is a risk factor predisposing to its occurrence and complications. However, it is still unclear the association between physical inactivity domains and hypertension, especially in public healthcare systems. Thus, this study aimed to investigate the association between physical inactivity aggregation in different domains and prevalence of hypertension among users of Brazilian public health system. 963 participants composed the sample. Subjects were divided into quartiles groups according to three different domains of physical activity (occupational; physical exercises; and leisure-time and transportation). Hypertension was based on physician diagnosis. Physical inactivity in occupational domain was significantly associated with higher prevalence of hypertension (OR = 1.52 [1.05 to 2.21]). The same pattern occurred for physical inactivity in leisure-time (OR = 1.63 [1.11 to 2.39]) and aggregation of physical inactivity in three domains (OR = 2.46 [1.14 to 5.32]). However, the multivariate-adjusted model showed significant association between hypertension and physical inactivity in three domains (OR = 2.57 [1.14-5.79]). The results suggest an unequal prevalence of hypertension according to physical inactivity across different domains and increasing the promotion of physical activity in the healthcare system is needed.