Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time s...Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure(Co P)fluctuations.Multiscale entropy(MSE) has been used to identify differences in fluctuations of postural Co P time series between groups with and without known physiological impairments at multiple time scales.The purpose of this paper is to:1) review basic elements and current developments in entropy techniques used to assess physiological complexity;and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underlie the control of posture.We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control.This evidence emerges from observed lower MSE values in individuals with multiple sclerosis,idiopathic scoliosis,and in older individuals with sensory impairments.Finally,we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations;this information may improve the development and evaluation of new therapeutic interventions.展开更多
The intergranular corrosion and exfoliation corrosion of 2195 Al-Li alloy treated by multi-step heating-rate controlled aging （MSRC） are studied. The corrosion features of 2195 Al-Li alloys which are respectively tr...The intergranular corrosion and exfoliation corrosion of 2195 Al-Li alloy treated by multi-step heating-rate controlled aging （MSRC） are studied. The corrosion features of 2195 Al-Li alloys which are respectively treated by high-temperature nucleation MSRC （H-M） and low-temperature nucleation MSRC （L-M） are contrasted. And the corrosion mechanism of 2195 A1-Li alloy is also discussed from the viewpoint of microstructure （types, distribution, etc.） of the strengthening phase. The results show that 2195 A1-Li alloy after H-M is more susceptible to intergranular corrosion and exfoliation corrosion than that of alloy after L-M. The degree of intergranular corrosion increases with the increase of predeformation amount and the surface parallel to the rolling direction is more prone to exfoliation corrosion. The main reason of intergranular corrosion and exfoliation corrosion is the formation of corrosion galvanic couples among T1 phase, θ＇ phase and grain boundary precipitate-free zones （PFZ）.展开更多
文摘Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure(Co P)fluctuations.Multiscale entropy(MSE) has been used to identify differences in fluctuations of postural Co P time series between groups with and without known physiological impairments at multiple time scales.The purpose of this paper is to:1) review basic elements and current developments in entropy techniques used to assess physiological complexity;and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underlie the control of posture.We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control.This evidence emerges from observed lower MSE values in individuals with multiple sclerosis,idiopathic scoliosis,and in older individuals with sensory impairments.Finally,we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations;this information may improve the development and evaluation of new therapeutic interventions.
基金National Basic Research Program of China(2010CB934700)
文摘The intergranular corrosion and exfoliation corrosion of 2195 Al-Li alloy treated by multi-step heating-rate controlled aging （MSRC） are studied. The corrosion features of 2195 Al-Li alloys which are respectively treated by high-temperature nucleation MSRC （H-M） and low-temperature nucleation MSRC （L-M） are contrasted. And the corrosion mechanism of 2195 A1-Li alloy is also discussed from the viewpoint of microstructure （types, distribution, etc.） of the strengthening phase. The results show that 2195 A1-Li alloy after H-M is more susceptible to intergranular corrosion and exfoliation corrosion than that of alloy after L-M. The degree of intergranular corrosion increases with the increase of predeformation amount and the surface parallel to the rolling direction is more prone to exfoliation corrosion. The main reason of intergranular corrosion and exfoliation corrosion is the formation of corrosion galvanic couples among T1 phase, θ＇ phase and grain boundary precipitate-free zones （PFZ）.
