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The age-specific rates of hip fractures have been declining in most countries in the West but a few studies suggest that the rates might be increasing in areas of Asia that are undergoing urbanization. We previously conducted a population-based study of hip fracture rates in Beijing, China, in 1990 to 1992 that included validation of hip fracture cases. Using a similar approach to validate cases, we estimated the age-specific hip fracture rates in Beijing, China, for 2002 to 2006. Specifically, we obtained hospital discharge data for hip fractures that were reported to the Beijing Bureau of Public Health. To confirm the diagnoses, Beijing residence, and find cases missed by the public records we checked individual cases in the public health records against medical records in a random sample of Beijing hospitals. The rates from public health data were adjusted for these under-and overestimations. We found that between 1990 and 1992 and 2002 and 2006, the adjusted age-specific rates of hip fracture over age 50 years increased 2.76-fold (95% confidence interval [CI], 2.68-2.84) in women and 1.61-fold (95% CI, 1.56-1.66) in men. Over age 70 years, the age-specific rates increased 3.37-fold (95% CI, 3.28-3.47) in women and 2.01-fold (95% CI, 1.95-2.07) in men. From 2002 to 2006, the rates over age 50 years increased 58% in women and 49% in men. We conclude that the rate of hip fracture has been rising very rapidly in Beijing, China. Therefore, the burden of hip fractures may be shifting rapidly from the West to urbanizing areas of the East. ß

No abstract

In this paper, we demonstrated a room-temperature acetone gas sensor based on tin dioxide (SnO 2 )-reduced graphene oxide (RGO) hybrid composite film. The SnO 2 -RGO composite film sensor was fabricated on PCB substrate with rectangular-ambulatory-plane interdigital microelectrodes by using a facile hydrothermal method. The presence of small-sized SnO 2 nanoparticles on RGO sheets was 10 characterized by SEM, XRD and BET measurement, demonstrating well-structures without irreversible restacking of sheets and agglomeration. The sensing properties of the SnO 2 -RGO hybrid film sensor were investigated by exposing to various concentration of acetone gas at room temperature. It was found that the presented sensor exhibited not only excellent response to acetone gas, but also fast response-recovery time and good repeatability, exhibiting the unique advantages of SnO 2 -RGO hybrid composite as a 15 building block for sensor fabrication. The gas response of the SnO 2 -RGO hybrid composite was about 2-fold higher than that of the pure RGO film, and the possible sensing mechanism was mainly attributed to the high surface area, three-dimensional porous nanostructure and special interactions between RGO sheets and SnO 2 nanoparticles.