A multiple time step algorithm,called reversible reference system propagator algorithm,is introduced for the long time molecular dynamics simulation.In contrast to the conventional algorithms,the multiple time method ...A multiple time step algorithm,called reversible reference system propagator algorithm,is introduced for the long time molecular dynamics simulation.In contrast to the conventional algorithms,the multiple time method has better convergence,stability and efficiency.The method is validated by simulating free relaxation and the hypervelocity impact of nano-clusters.The time efficiency of the multiple time step method enables us to investigate the long time interaction between lattice dislocations and low-angle grain boundaries.展开更多
Knee dislocations frequently involve vascular injuries that demand early diagnosis and timely intervention. Time of ischemia is pivotal in determining the outcome for the limb, delays in treatment beyond 8 hours signi...Knee dislocations frequently involve vascular injuries that demand early diagnosis and timely intervention. Time of ischemia is pivotal in determining the outcome for the limb, delays in treatment beyond 8 hours significantly increase the risk of limb loss. Unfortunately, this critical window is often missed in resource-limited settings. Here we report a 25-year-old female sustained a left knee injury after falling into a trench. She was diagnosed with an open knee dislocation accompanied by a popliteal artery injury. However, revascularization was delayed for 18 hours due to limited resources, including the unavailability of a thrombectomy catheter. Postoperatively, the patient received anticoagulation therapy with serial limb assessments and after 3 weeks the laceration healed and the limb was still viable. Knee dislocations frequently result in vascular injury (popliteal artery most common), making prompt diagnosis and intervention essential for limb preservation. In settings with limited resources, like ours, delayed presentation and transfer to specialized centers contribute to prolonged ischemic times. Nonetheless, viable limbs should be revascularized in stable patients, even with prolonged ischemia. This case highlights the importance of limb revascularization despite delay. Efforts should be made to improve prompt diagnosis, timely referral, and availability of necessary equipment for vascular repair to optimize outcomes in similar cases.展开更多
基金The project supported by the National Natural Science Foundation of China(the 973 Project 2004CB619304).
文摘A multiple time step algorithm,called reversible reference system propagator algorithm,is introduced for the long time molecular dynamics simulation.In contrast to the conventional algorithms,the multiple time method has better convergence,stability and efficiency.The method is validated by simulating free relaxation and the hypervelocity impact of nano-clusters.The time efficiency of the multiple time step method enables us to investigate the long time interaction between lattice dislocations and low-angle grain boundaries.
文摘Knee dislocations frequently involve vascular injuries that demand early diagnosis and timely intervention. Time of ischemia is pivotal in determining the outcome for the limb, delays in treatment beyond 8 hours significantly increase the risk of limb loss. Unfortunately, this critical window is often missed in resource-limited settings. Here we report a 25-year-old female sustained a left knee injury after falling into a trench. She was diagnosed with an open knee dislocation accompanied by a popliteal artery injury. However, revascularization was delayed for 18 hours due to limited resources, including the unavailability of a thrombectomy catheter. Postoperatively, the patient received anticoagulation therapy with serial limb assessments and after 3 weeks the laceration healed and the limb was still viable. Knee dislocations frequently result in vascular injury (popliteal artery most common), making prompt diagnosis and intervention essential for limb preservation. In settings with limited resources, like ours, delayed presentation and transfer to specialized centers contribute to prolonged ischemic times. Nonetheless, viable limbs should be revascularized in stable patients, even with prolonged ischemia. This case highlights the importance of limb revascularization despite delay. Efforts should be made to improve prompt diagnosis, timely referral, and availability of necessary equipment for vascular repair to optimize outcomes in similar cases.
