The paper analyzes the radon data of nearly two decades on the Jiayuguan fault zone,discusses the main influencing factors,and puts forward the relationship between radon and air temperature,ground temperature and rai...The paper analyzes the radon data of nearly two decades on the Jiayuguan fault zone,discusses the main influencing factors,and puts forward the relationship between radon and air temperature,ground temperature and rainfall.We summarized the earthquake reflecting effect for ML≥5.0 about 400km within the Jiayuguan station,and reached the conclusion that it has better earthquake-reflecting ability before an earthquake,usually appearing as abnormal changes in sustained low value.By extracting the annual trend of radon in Jiayuguan station over many years,we discovered that the annual trend of radon has a close relationship with the seismic activity in surrounding areas,namely,if the annual variation of radon is larger,the seismic activity in surrounding areas is stronger;Otherwise,if the annual variation of radon is relatively stable,the seismic activity in the vicinity is weak.展开更多
Purpose： The aim of this study was to investigate the incidence of Z-effect after dual lag screw intramedullary nailing systems and risk factors contributing to this effect. We hypothesized that long nails provide mo...Purpose： The aim of this study was to investigate the incidence of Z-effect after dual lag screw intramedullary nailing systems and risk factors contributing to this effect. We hypothesized that long nails provide more neck strength due to a longer lever than short nails and are therefore less likely to develop a misbalance of a higher head compressive strength than neck compressive strength, Methods： In this retrospective cohort study 103 patients treated operatively with a dual lag screw intramedullary nailing device for （sub）trochanteric hip fracture were included, We analysed patient charts regarding patient and operation characteristics. Furthermore we conducted radiologic mea- surements within the 2-year follow-up period to investigate the quality of fracture fixation, implant failure and predictors for Z-effect. The re-operation risk was investigated with multivariate regression analysis, Results： The incidence of （reversed） Z-effect in this study was 9% （n 80）; 6 out of 7 Z-effects occurred in the short nail group, which was not significant. Patients who were treated with a long nail had a significant larger number of complications in comparison with the short nail group （median 2 vs 0,5, p = 0.001）. The long nail group received more often erythrocytes blood transfusions （82% vs 31%, p 〈 0.01） and had a longer hospital stay （13 vs 21 days, p 〈 0.05）. Migration of lag screws （p 〈0.05） and unstable fracture type （p 〈 0.05）, were risk factors for re-operation. The re-operation rate within 2 year after surgery was 21%, of which one fourth was due to a Z-effect. Conclusion： The nail length was not associated with the development of a Z-effect. Migration of lag screws after intramedullary nailing is common and a risk factor for re-operation.展开更多
基金sponsored by the Youth Fund of China Earthquake Networks Center (150-1548,406-1503)
文摘The paper analyzes the radon data of nearly two decades on the Jiayuguan fault zone,discusses the main influencing factors,and puts forward the relationship between radon and air temperature,ground temperature and rainfall.We summarized the earthquake reflecting effect for ML≥5.0 about 400km within the Jiayuguan station,and reached the conclusion that it has better earthquake-reflecting ability before an earthquake,usually appearing as abnormal changes in sustained low value.By extracting the annual trend of radon in Jiayuguan station over many years,we discovered that the annual trend of radon has a close relationship with the seismic activity in surrounding areas,namely,if the annual variation of radon is larger,the seismic activity in surrounding areas is stronger;Otherwise,if the annual variation of radon is relatively stable,the seismic activity in the vicinity is weak.
文摘Purpose： The aim of this study was to investigate the incidence of Z-effect after dual lag screw intramedullary nailing systems and risk factors contributing to this effect. We hypothesized that long nails provide more neck strength due to a longer lever than short nails and are therefore less likely to develop a misbalance of a higher head compressive strength than neck compressive strength, Methods： In this retrospective cohort study 103 patients treated operatively with a dual lag screw intramedullary nailing device for （sub）trochanteric hip fracture were included, We analysed patient charts regarding patient and operation characteristics. Furthermore we conducted radiologic mea- surements within the 2-year follow-up period to investigate the quality of fracture fixation, implant failure and predictors for Z-effect. The re-operation risk was investigated with multivariate regression analysis, Results： The incidence of （reversed） Z-effect in this study was 9% （n 80）; 6 out of 7 Z-effects occurred in the short nail group, which was not significant. Patients who were treated with a long nail had a significant larger number of complications in comparison with the short nail group （median 2 vs 0,5, p = 0.001）. The long nail group received more often erythrocytes blood transfusions （82% vs 31%, p 〈 0.01） and had a longer hospital stay （13 vs 21 days, p 〈 0.05）. Migration of lag screws （p 〈0.05） and unstable fracture type （p 〈 0.05）, were risk factors for re-operation. The re-operation rate within 2 year after surgery was 21%, of which one fourth was due to a Z-effect. Conclusion： The nail length was not associated with the development of a Z-effect. Migration of lag screws after intramedullary nailing is common and a risk factor for re-operation.
