To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions...To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed soil.In this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging condition.First,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ sampling.Subsequently,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil heterogeneity.The results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed soil.Therefore,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.展开更多
Aims: To determine the effects of digoxin on all-cause mortality and heart failure(HF) hospitalizations, regardless of ejection fraction, accounting for serum digoxin concentration(SDC). Methods and results: This comp...Aims: To determine the effects of digoxin on all-cause mortality and heart failure(HF) hospitalizations, regardless of ejection fraction, accounting for serum digoxin concentration(SDC). Methods and results: This comprehensive post-hoc analysis of the randomized controlled Digitalis Investigation Group trial(n=7788) focuses on 5548 patients: 1687 with SDC, drawn randomly at 1 month, and 3861 placebo patients, alive at 1 month. Overall, 33% died and 31% had HF hospitalizations during a 40-month median follow-up. Compared with placebo, SDC 0.5- 0.9 ng/mL was associated with lower mortality[29 vs. 33% placebo; adjusted hazard ratio(AHR), 0.77; 95% confidence interval(CI), 0.67- 0.89], all-cause hospitalizations(64 vs. 67% placebo; AHR, 0.85; 95% CI, 0.78- 0.92) and HF hospitalizations(23 vs. 33% placebo; AHR, 0.62; 95% CI, 0.54- 0.72). SDC ≥ 1.0 ng/mL was associated with lower HF hospitalizations(29 vs. 33% placebo; AHR, 0.68; 95% CI, 0.59- 0.79), without any effect on mortality. SDC 0.5- 0.9 reduced mortality in a wide spectrum of HF patients and had no interaction with ejection fraction >45% (P=0.834) or sex(P=0.917). Conclusions: Digoxin at SDC 0.5- 0.9 ng/mL reduces mortality and hospitalizations in all HF patients, including those with preserved systolic function. At higher SDC, digoxin reduces HF hospitalization but has no effect on mortality or all-cause hospitalizations.展开更多
基金supported by the Natural Science Foundation of Hainan Province(Grant No.520LH015)the Fundamental Research Funds for the Central Universities and the Major Projects of Strategic Emerging Industries in Shanghai(Grant No.BH3230001).
文摘To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed soil.In this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging condition.First,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ sampling.Subsequently,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil heterogeneity.The results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed soil.Therefore,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.
文摘Aims: To determine the effects of digoxin on all-cause mortality and heart failure(HF) hospitalizations, regardless of ejection fraction, accounting for serum digoxin concentration(SDC). Methods and results: This comprehensive post-hoc analysis of the randomized controlled Digitalis Investigation Group trial(n=7788) focuses on 5548 patients: 1687 with SDC, drawn randomly at 1 month, and 3861 placebo patients, alive at 1 month. Overall, 33% died and 31% had HF hospitalizations during a 40-month median follow-up. Compared with placebo, SDC 0.5- 0.9 ng/mL was associated with lower mortality[29 vs. 33% placebo; adjusted hazard ratio(AHR), 0.77; 95% confidence interval(CI), 0.67- 0.89], all-cause hospitalizations(64 vs. 67% placebo; AHR, 0.85; 95% CI, 0.78- 0.92) and HF hospitalizations(23 vs. 33% placebo; AHR, 0.62; 95% CI, 0.54- 0.72). SDC ≥ 1.0 ng/mL was associated with lower HF hospitalizations(29 vs. 33% placebo; AHR, 0.68; 95% CI, 0.59- 0.79), without any effect on mortality. SDC 0.5- 0.9 reduced mortality in a wide spectrum of HF patients and had no interaction with ejection fraction >45% (P=0.834) or sex(P=0.917). Conclusions: Digoxin at SDC 0.5- 0.9 ng/mL reduces mortality and hospitalizations in all HF patients, including those with preserved systolic function. At higher SDC, digoxin reduces HF hospitalization but has no effect on mortality or all-cause hospitalizations.
