Risk prediction of second hip fracture by bone and muscle density of the hip varies with time after first hip fracture: a prospective cohort study

Purpose: Predictors of 'imminent' risk of second hip fracture are unknown. The aims of the study were to explore strength of hip areal bone mineral density (aBMD), and muscle area and density for predicting second hip fracture at different time intervals.Methods: Data of the Chinese Second Hip Fracture Evaluation were analyzed, a longitudinal study to evaluate the risk of second hip fracture (of the contralateral hip) by using CT images obtained immediately after first hip fracture. Muscle cross-sectional area and density were measured of the gluteus maximus (G.MaxM) and gluteus medius and minimus (G.Med/MinM) and aBMD of the proximal femur at the contralateral unfractured side. Patients were followed up for a median time of 4.5 years. Separate Cox models were used to predict second hip fracture risk at different time intervals after first event adjusted for age, sex, BMI and diabetes. Results: The mean age of subjects with imminent (within 1st or 2nd year) second hip fracture was 79.80 +/- 5.16 and 81.56 +/- 3.64 years. In the 1st year after the first hip fracture, femoral neck (FN) aBMD predicted second hip fracture (HR 5.88; 95 % CI, 1.32-26.09). In the remaining years of follow-up after 2nd year, muscle density predicted second hip fracture (G.MaxM HR 2.13; 95 % CI, 1.25-3.65,G.Med/MinM HR 2.10; 95 % CI, 1.32-3.34).Conclusions: Our results show that femoral neck aBMD is an important predictor for second hip fracture within the first year and therefore suggest supports the importance concept of early and rapid-acting bone-active drugs to increase hip BMD. In addition, the importance of muscle density predicting second hip fracture after the second year suggest post hip fracture rehabilitation and exercise programs could also be important to reduce muscle fatty infiltration.Metabolic health: pathophysiological trajectories and therap

The Civil Aviation Pilots hypertensive patients heart rate variability and baroreflex sensitivity analysis: analysis of heart rate variability and baroreflex sensitivity in civil flying personnel with hypertension

To explore the Civil Aviation Pilots hypertensive patients cardiovascular autonomic nervous regulation of the changes to provide a reasonable basis for hypertension control. Methods: To use conventional AR spectral analysis methods on 14 cases of civil aviation pilots hypertensive patients and 14 healthy pilots Short-term heart rate variability (HRV) signal analysis, sequential analysis at the same time using its baroreflex sensitivity (BRS). Results: Compared with the control group, the HRV hypertensive patients decreased significantly, the difference was significant (P <0.05), showed total power (TP), low-frequency power (LF), high-frequency power (HF) and the normalization of the high-frequency components (HFn) lower, and normalization of the low-frequency component (LFn) and LF / HF increased; ? the BRS hypertensive patients compared with the control group decreased, the difference was significant (P <0.01). Conclusions: Pilots hypertensive patients regulatory function of the cardiovascular autonomic nervous obvious anomaly, a relatively sympathetic regulatory activities increased, vagus nerve regulatory activities be curbed. flight personnel in the control of hypertension, should strengthen its regulatory function of the autonomic nervous analysis

An investigation of interface bonding of bimetallic foils by combined accumulative roll bonding and asymmetric rolling techniques

The bond strength in bimetallic materials is an important material characteristic. In this study, 0.1-mm thick bimetallic foils (AA1050/AA6061) were produced using one pass of accumulative roll bonding followed by three passes of asymmetric rolling (AR). The AR passes were carried out at roll speed ratios of 1.0, 1.1, 1.2, 1.3, and 1.4 separately. Finite element simulation was used to model the deformation of the bimetallic foils for the various experimental conditions. Particular attention was focused on the bonding of the interface between AA1050 and AA6061 layers in the simulation. The optimization of the roll speed ratio was obtained for improvement of the bond strength of the interface of AA1050/AA6061 bimetallic foils during AR process. In the simulation, the mean equivalent strain at the interface zone between the AA1050 and AA6061 layers was seen to reach a peak value at a roll speed ratio of about 1.2 to 1.3, which also corresponded to a high quality bond at the interface as observed experimentally