Transcatheter aortic valve implantation （TAVR） has emerged as an alternative, rapidly evolving treatment option for patients with se- vere aortic stenosis and high surgical risk. Stroke is a devastating complication...Transcatheter aortic valve implantation （TAVR） has emerged as an alternative, rapidly evolving treatment option for patients with se- vere aortic stenosis and high surgical risk. Stroke is a devastating complication being confined mainly in the periprocedural and 30-day pe- riod following TAVR, with a lower and relatively constant frequency thereafter. Early stroke is mainly due to debris embolization during the procedure, whereas later events are associated with patient specific factors. Despite the fact that the rate of clinical stroke has been constantly decreasing compared to initial TAVR experience, modern neuro-imaging with MRI suggests that new ischemic lesions post-TAVR are almost universal. The impact of the latter is largely unknown. However, they seem to correlate with a reduction in neurocognitive function. Because TAVR is set to expand its indication to lower surgical-risk patients, stroke prophylaxis during and after TAVR becomes of paramount importance. Based on clinical and pathophysiological evidence, three lines of research are actively employed towards this direction： improvement in valve and delivery system technology with an aim to reduce manipulations and contact with the calcified aortic arch and native valve, antithrombotic therapy, and embolic protection devices. Careful patient selection, design of the procedure, and tailored antithrombotic strategies respecting the bleeding risks of this fragile population constitute the main defense against stroke following TAVR.展开更多
A discrete-event system simulation and animation program was developed to enhance the efficiency of a truck-excavator operation and reduce the environmental impact of haulage in an open-cut coal mine with multiple-pit...A discrete-event system simulation and animation program was developed to enhance the efficiency of a truck-excavator operation and reduce the environmental impact of haulage in an open-cut coal mine with multiple-pit operations. In any mine, a key objective is to have sufficient equipment for production and not to have excess to where it becomes counterproductive. Due to the advent of responsible mining,environmental regulations, and eco-friendly practices, these factors must also be considered in the analysis. Simulation studies can be financially advantageous for both the optimization of existing mine operations and new development phases in a mine. This study is a new approach to use discrete-event system simulation for mine systems, in order to investigate and possibly reduce environmental impact considering mining haulage performance and production target. A hypothetical layout of a surface coal mine with two pit operations was used for the simulation and animation model. The simulation model includes the animation of the operation. Animation is helpful to enhance the benefit of a mine simulation model. GPSS/Hòand Proof Professionalòwere the software used for the investigation.展开更多
Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a n...Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a natural disaster such as earthquake happens. Based on the characteristics of emergency rescue in alpinecold region,several multifunctional protective equipments have been developed by the Quartermaster Equipment Institute of General Logistics Departmen(tGLD)of the Chinese People's Liberation Army(CPLA). These equipments are lightweight,durable and environment adaptable.展开更多
文摘Transcatheter aortic valve implantation （TAVR） has emerged as an alternative, rapidly evolving treatment option for patients with se- vere aortic stenosis and high surgical risk. Stroke is a devastating complication being confined mainly in the periprocedural and 30-day pe- riod following TAVR, with a lower and relatively constant frequency thereafter. Early stroke is mainly due to debris embolization during the procedure, whereas later events are associated with patient specific factors. Despite the fact that the rate of clinical stroke has been constantly decreasing compared to initial TAVR experience, modern neuro-imaging with MRI suggests that new ischemic lesions post-TAVR are almost universal. The impact of the latter is largely unknown. However, they seem to correlate with a reduction in neurocognitive function. Because TAVR is set to expand its indication to lower surgical-risk patients, stroke prophylaxis during and after TAVR becomes of paramount importance. Based on clinical and pathophysiological evidence, three lines of research are actively employed towards this direction： improvement in valve and delivery system technology with an aim to reduce manipulations and contact with the calcified aortic arch and native valve, antithrombotic therapy, and embolic protection devices. Careful patient selection, design of the procedure, and tailored antithrombotic strategies respecting the bleeding risks of this fragile population constitute the main defense against stroke following TAVR.
文摘A discrete-event system simulation and animation program was developed to enhance the efficiency of a truck-excavator operation and reduce the environmental impact of haulage in an open-cut coal mine with multiple-pit operations. In any mine, a key objective is to have sufficient equipment for production and not to have excess to where it becomes counterproductive. Due to the advent of responsible mining,environmental regulations, and eco-friendly practices, these factors must also be considered in the analysis. Simulation studies can be financially advantageous for both the optimization of existing mine operations and new development phases in a mine. This study is a new approach to use discrete-event system simulation for mine systems, in order to investigate and possibly reduce environmental impact considering mining haulage performance and production target. A hypothetical layout of a surface coal mine with two pit operations was used for the simulation and animation model. The simulation model includes the animation of the operation. Animation is helpful to enhance the benefit of a mine simulation model. GPSS/Hòand Proof Professionalòwere the software used for the investigation.
文摘Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a natural disaster such as earthquake happens. Based on the characteristics of emergency rescue in alpinecold region,several multifunctional protective equipments have been developed by the Quartermaster Equipment Institute of General Logistics Departmen(tGLD)of the Chinese People's Liberation Army(CPLA). These equipments are lightweight,durable and environment adaptable.
