Background: Reduced bone density is a major risk factor for fragility fracture. Previous studies reported, that 69% to 100% of patients with fragility fractures had low bone mineral density (BMD). Objective: The objec...Background: Reduced bone density is a major risk factor for fragility fracture. Previous studies reported, that 69% to 100% of patients with fragility fractures had low bone mineral density (BMD). Objective: The objective of the study is to estimate the prevalence of osteoporosis and osteopenia among patients with fragility fractures. Results: The result of the study revealed that the mean age of patients included in the study was 65.11 ± 10.17 and the majority (77.3%) were females. The most common sites of fractures were the femur, radius and vertebra (30.7%, 17.0% and 14.8% respectively). Moreover, more than 95% of patients with fragility fracture who underwent BMD testing had low bone mineral density. In female with fragility fracture the prevalence of osteoporosis was higher in comparison to male (58.8% and 45.0% respectively). Conclusion: Our data showed that low BMD measurement is prevalent in patient with fragility fracture. It also highlighted the importance of implementation of Fracture liaison service, to reduce the gap between fragility fracture and osteoporosis treatment.展开更多
The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high f...The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high flexibility and low fabrication cost. We modified theoretical approach for piezoresistivity simulation from our original method for semiconductor systems to improved procedure applicable to conductor systems. The variations of carrier conductivity due to strain along with the graphene ribbon models (armchair model and zigzag model) have been calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional electronic band diagram. We found that the armchair-type graphene nano-ribbon models have low conductivity with heavy effective mass. This is a totally different conductivity from two-dimensional graphene sheet. The variation of band energy diagrams of the zigzag-type graphene nano-ribbon models due to strain is much more sensitive than that of the armchair models. As a result, the longitudinal and transverse gauge factors are high in our calculation, and in particular, the zigzag-type graphene ribbon has an enormous potential material with high piezoresistivity. So, it will be one of the most important candidates that can be used as a high-performance piezoresistive material for fabricating a new high sensitive strain gauge sensor.展开更多
文摘Background: Reduced bone density is a major risk factor for fragility fracture. Previous studies reported, that 69% to 100% of patients with fragility fractures had low bone mineral density (BMD). Objective: The objective of the study is to estimate the prevalence of osteoporosis and osteopenia among patients with fragility fractures. Results: The result of the study revealed that the mean age of patients included in the study was 65.11 ± 10.17 and the majority (77.3%) were females. The most common sites of fractures were the femur, radius and vertebra (30.7%, 17.0% and 14.8% respectively). Moreover, more than 95% of patients with fragility fracture who underwent BMD testing had low bone mineral density. In female with fragility fracture the prevalence of osteoporosis was higher in comparison to male (58.8% and 45.0% respectively). Conclusion: Our data showed that low BMD measurement is prevalent in patient with fragility fracture. It also highlighted the importance of implementation of Fracture liaison service, to reduce the gap between fragility fracture and osteoporosis treatment.
文摘The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high flexibility and low fabrication cost. We modified theoretical approach for piezoresistivity simulation from our original method for semiconductor systems to improved procedure applicable to conductor systems. The variations of carrier conductivity due to strain along with the graphene ribbon models (armchair model and zigzag model) have been calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional electronic band diagram. We found that the armchair-type graphene nano-ribbon models have low conductivity with heavy effective mass. This is a totally different conductivity from two-dimensional graphene sheet. The variation of band energy diagrams of the zigzag-type graphene nano-ribbon models due to strain is much more sensitive than that of the armchair models. As a result, the longitudinal and transverse gauge factors are high in our calculation, and in particular, the zigzag-type graphene ribbon has an enormous potential material with high piezoresistivity. So, it will be one of the most important candidates that can be used as a high-performance piezoresistive material for fabricating a new high sensitive strain gauge sensor.
