Prevalence of and factors associated with frailty and disability in older adults from China, Ghana, India, Mexico, Russia and South Africa.

BACKGROUND: The severe burden imposed by frailty and disability in old age is a major challenge for healthcare systems in low- and middle-income countries alike. The current study aimed to provide estimates of the prevalence of frailty and disability in older adult populations and to examine their relationship with socioeconomic factors in six countries. METHODS: Focusing on adults aged 50+ years, a frailty index was constructed as the proportion of deficits in 40 variables, and disability was assessed using the World Health Organization Disability Assessment Schedule (WHODAS 2.0), as part of the Study on global AGEing and adult health (SAGE) Wave 1 in China, Ghana, India, Mexico, Russia and South Africa. RESULTS: This study included a total of 34,123 respondents. China had the lowest percentages of older adults with frailty (13.1%) and with disability (69.6%), whereas India had the highest percentages (55.5% and 93.3%, respectively). Both frailty and disability increased with age for all countries, and were more frequent in women, although the sex gap varied across countries. Lower levels of both frailty and disability were observed at higher levels of education and wealth. Both education and income were protective factors for frailty and disability in China, India and Russia, whereas only income was protective in Mexico, and only education in South Africa. CONCLUSIONS: Age-related frailty and disability are increasing concerns for older adult populations in low- and middle-income countries. The results indicate that lower levels of frailty and disability can be achieved for older people, and the study highlights the need for targeted preventive approaches and support programs.

Effect of compressive straining on corrosion resistance of a shape memory Ni-Ti alloy in Ringer's solution.

The effect of various degrees of deformation was investigated at specific locations in the stress-strain curve under compression on the corrosion resistance of a wrought Ni-Ti alloy with a martensite to austenite transformation peak of 110 degrees C. Two metallurgical conditions were evaluated: 30% cold drawn and annealed at 900 degrees C for 1 h. The cold drawn material was tested for corrosion resistance after 5.8, 7.4, 12.2, and 24.5% applied strain. Similarly, the corrosion resistance of the annealed material condition was examined after deformation in compression to 11.9, 22.3, and 24.4% strain. Tafel extrapolation and cyclic polarization tests were used for corrosion characterization of each alloy condition. It was found that the corrosion current density undergoes a significant reduction while the breakdown potential improves at increasing strains. In particular, the alloy in the annealed condition exhibited breakdown potentials above 1000 mV with current densities lower than 10 microA cm-2 when it was strained to 24.4%.

Deformation behavior of low-carbon Co-Cr-Mo alloys for low-friction implant applications.

The plastic flow behavior of wrought Co-27Cr-5Mo-0.05C alloy was investigated at 298 K as a function of grain size using uniaxial tension testing. The microstructures produced by deformation were characterized using X-ray diffraction, reflected light, and scanning electron microscopy. This study revealed that material with initially coarse face-centered cubic (fcc) grains exhibits larger uniform ductility than material with fine grain size. Typically, increasing the grain size from 7 to 70 microns reduces the yield strength by about 50% and increases the elongation to fracture from 12 to 30% with a small effect on the tensile strength. The material is capable of deforming uniformly to large strains without developing plastic instabilities until the point of fracture. This effect was found to be associated with the occurrence of transformation-induced plasticity (TRIP) in the coarse-grained material. TRIP enhances the material's ability to deform uniformly by maintaining a high rate of strain hardening during deformation. Smaller fcc initial grain size inhibits the transformation kinetics of the fcc-hexagonal close-packed phase transition according to the Olson-Cohen model.