Bone mineral density in osteopenic early postmenopausal women practicing Pilates gymnastic for six years

Osteoporosis has a negative impact on health and is very frequent in women after menopause. Regular physical activity (PA) is known to reduce the bone loss associated with ageing across the lifespan. Aims: There are two aims of this study: (1) to compare the BMD values of an active female group at the end of the 5-th year with those at the end of 6-th year; (2) to compare the mineral bone density (BMD) in early menopausal women (50-65y), who followed a PA program twice a week, for 6 years with that of a similar group, who have not done any regular PA. Methods: 22 women recently entered menopause (56.53± 6.3 years, BMI 21.11±4.98 kg/m2) who have participated for 5 years the Pilates type fitness program, (60 minutes, 2x/week) formed the activel group (AG), and the sedentary group (SG) - 25 women (56.98±3.40 years, BMI 22.4±4.8kg/m2) with a sedentary lifestyle. Both groups underwent calcaneal ultrasound measurement with OsteoSysSonost 3000 device. Results: The bone parameters of the experimental group were the same, or have not changed significantly in the last year of physical activity. At follow-up (the end of the 6-th year) the bone parameters of AG and SG have generated significant differences favouring the active group (p<0.01). Conclusions: A Pilates fitness program of 12 months had not an impact on the BMD values of women in menopause, but BMD values did not decrease as expected in women of this age. Regular physical activity practiced over a six years period has led to greater BMD values for active early menopausal women than their sedentary peers

Polymer Dynamics in PEG-Silica Nanocomposites: Effects of Polymer Molecular Weight, Temperature and Solvent Dilution

The mechanical properties of particulate nanocomposites strongly depend upon the particle dispersion, as well as on the closely related properties in thin polymer films covering the particle surface. The length scale of such changes is relevant for the understanding of particle-particle interactions, which ultimately dominate the mechanical response. Using well-defined 44 nm diameter silica nanoparticles dispersed in poly(ethylene glycol), we focus on surface-induced changes in polymer dynamics. Using proton time-domain NMR, we distinguish three polymer phases of different mobility, i.e., a strongly adsorbed, solid-like fraction, a fraction with intermediate relaxation times and a highly mobile fraction. We explore how these fractions change as we vary polymer molecular weight from 300 to 20 000 and particle volume fraction up to 0.3. A multiple-quantum experiment enables a closer analysis of the mobile component which we show consists of two fractions, one resembling the bulk melt-like and another one showing network-like properties. We demonstrate that above a polymer molecular weight-dependent volume fraction, polymers form elastically active links between particles, resulting in the physical gelation observed in such systems. Our results provide a quantitative picture of network formation, which is described by the amount and length of network-like chains as well as heterogeneities in the polymer dynamics. We relate changes in polymer dynamics to particle microstructure obtained from small angle neutron scatteringclose181