Acidolysis is emerging as a promising method for recycling polyurethane foam (PUF) waste. Here, we present highly efficient acidolysis of PUFs with adipic acid (AA) by heating the reaction mixtures with microwaves. The influence of experimental conditions, such as reaction temperature, time, and amount of the degradation reagent, on the polyol functionality, molecular weight characteristics, the presence of side products, and the degree of degradation of the remaining PUF hard segments was studied by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), nuclear magnetic resonance (NMR), size-exclusion chromatography (SEC) coupled to a multidetection system, and Fourier transform infrared (FT-IR) spectroscopy. The purified recycled polyols were used for the synthesis of flexible PUFs. The morphology and mechanical properties of the PUFs show that the degree of functionalization of the polyol by the carboxylic end groups, which is higher for larger amounts of AA used to degrade the PUFs, significantly affects the quality and performance of the flexible PUFs from the recycled polyols.
The main coffee diterpenes cafestol, kahweol, and 16-O-methylcafestol, present in the bean lipid fraction, are mostly esterified with fatty acids. They are believed to induce dyslipidaemia and hypercholesterolemia when taken with certain types of coffee brews. The study of their binding to serum albumins could help explain their interactions with biologically active xenobiotics. We investigated the interactions occurring between cafestol and 16-O-methylcafestol palmitates with Bovine Serum Albumin (BSA), Human Serum Albumin (HSA), and Fatty Free Human Serum Albumin (ffHSA) by means of circular dichroism and fluorimetry. Circular Dichroism (CD) revealed a slight change (up to 3%) in the secondary structure of fatty-free human albumin in the presence of the diterpene esters, suggesting that the aliphatic chain of the palmitate partly occupies one of the fatty acid sites of the protein. A warfarin displacement experiment was performed to identify the binding site, which is probably close but not coincident with Sudlow site I, as the affinity for warfarin is enhanced. Fluorescence quenching titrations revealed a complex behaviour, with Stern–Volmer constants in the order of 103–104 Lmol−1. A model of the HSA-warfarin-cafestol palmitate complex was obtained by docking, and the most favourable solution was found with the terpene palmitate chain inside the FA4 fatty acid site and the cafestol moiety fronting warfarin at the interface with site I.
The main purpose of the study was to examine the longitudinal associations between fat mass and fat free mass with health-related physical fitness. Two-hundred and forty 15-year old adolescent girls were measured at the baseline and after a period of 3 years (17 y). Health-related physical fitness included the following tests: (1) explosive power of the lower extremities (standing broad jump); (2) muscle endurance of the trunk (sit-ups in 60 s); (3) flexibility (sit-and-reach test); (4) muscle endurance of the lower extremities (squats in 60 s); (5) aerobic endurance (the 800 m run test); and (6) speed endurance (the 400 m running test). Fat mass and fat free mass were assessed using the bioelectrical impedance method. Longitudinal associations were analyzed with linear mixed model estimates. After adjusting for body mass index, fat mass was negatively associated with standing broad jump (β = −1.13, p < 0.001), sit-ups in 60 s (β = −0.27, p < 0.001), and squats in 60 s (β = −0.27, p < 0001), while positive associations with the 800 m running test (β = 0.02, p < 0.001) and the 400 m running test (β = 0.02, p < 0.001) were observed. On the other hand, fat free mass was positively associated with standing broad jump (β = 1.14, p < 0.001), sit-ups in 60 s (β = 0.28, p < 0.001), and squats in 60 s (β = 0.28, p < 0001), while the 800 m running test (β = −0.02, p < 0.001) and the 400 m running test (β = −0.02, p < 0.001) exhibited negative associations. This study shows that fat mass and fat free mass components are longitudinally, but oppositely associated with health-related physical fitness in adolescent girls.
Background Evidence has shown that higher levels of physical fitness (PF) in youth have beneficial effects on adult health-related outcomes. However, the tracking of separate PF components during adolescence has been less studied. Since PF often starts to rapidly decline during adolescence, it is necessary to provide information regarding critical time-point for interventions. This study aimed to analyze the extent of tracking the components of PF through PF tests. Methods In this longitudinal study, we recruited 240 adolescent girls with recoded data at 2 time-points (15 y and 17 y). PF included body composition (fat mass), explosive power of lower extremities (standing broad jump), muscle endurance of the trunk (sit-ups in 60 s), flexibility (sit-and-reach test), muscle endurance of lower extremities (squats in 60 s), aerobic endurance (the 800 m run test) and speed endurance (the 400 m run test). Tracking coefficients were calculated using generalized estimating equations. Tertiles (high, moderate and low) were calculated for each fitness component. Results The highest tracking coefficients between the two time-points were found for explosive power of lower extremities (β = 0.98), followed by flexibility (β = 0.89), body composition (β = 0.88), speed endurance (β = 0.86), aerobic endurance (β = 0.75), muscle endurance of lower extremities (β = 0.65), and muscle endurance of the trunk (β = 0.51). Tertile ratings remained stable across the two time-points. Conclusions Moderate to high tracking of PF in adolescent girls suggests that interventions aiming to increase the level of PF should probably begin in early adolescence.
BackgroundEvidence has shown that higher levels of physical fitness in youth have beneficial effects on adult health-related outcomes. However, the tracking of separate physical fitness components during adolescence has been less studied. Since physical fitness often starts to rapidly decline during adolescence, it is necessary to provide information regarding critical time-point for interventions. This study aimed to analyze the extent of tracking of several physical fitness tests. Methods In this longitudinal study, we recruited 240 adolescent girls with recoded data at 2 time-points (15 y and 17 y). Physical fitness included body composition (fat mass), explosive power of lower extremities (standing broad jump), muscle endurance of the trunk (sit-ups in 60 sec), flexibility (sit-and-reach test), muscle endurance of lower extremities (squats in 60 sec), aerobic endurance (the 800 m run test) and speed endurance (the 400 m run test). Tracking coefficients were calculated using generalized estimating equations. Tertiles (high, moderate and low) were calculated for each fitness component. Results The highest tracking coefficients between the two time-points were found for explosive power of lower extremities (β=0.98), followed by flexibility (β=0.89), body composition (β=0.88), speed endurance (β=0.86), aerobic endurance (β=0.75), muscle endurance of lower extremities (β=0.65), and muscle endurance of the trunk (β=0.51). Tertile ratings remained stable across the two time-points.ConclusionsModerate to high tracking of physical fitness in adolescent girls suggests that interventions aiming to increase the level of physical fitness should probably begin in early adolescence.
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