DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic chara...DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.展开更多
The ideal functional electrical stimulation (FES) system requires a mathematical model to provide feedforward control of the stimulation parameters such that they are optimal for different individuals across a range o...The ideal functional electrical stimulation (FES) system requires a mathematical model to provide feedforward control of the stimulation parameters such that they are optimal for different individuals across a range of physiological condi tions, muscles, and tasks. Recently we tested and validated such a model using a ble-bodied subjects. The purpose of this study was to determine whether this mo del applied to persons with spinal cord injuries (SCI). To this end, the isometr ic force responses of the paralyzed quadriceps femoris muscles of 14 adolescents and young adults were tested. For each subject, the force responses to two six -pulse stimulation trains were used to identify the parameter values of the mod el and then the model was used to predict the force responses to three train pat terns across a range of frequencies in both a nonfatigued and fatigued condition . The intraclass correlation coefficients (ICCs) between the experimental and pr edicted force-time integrals and peak forces were above 0.90 for 12 of the 13 s timulation trains tested in the nonfatigued condition and all 13 trains tested i n the fatigued condition. The success of our model with SCI subjects leads us to believe that our model may be useful for designing optimal stimulation paramete rs for standing and ambulation in patients who use FES.展开更多
E-selectin is a cell-adhesion molecule of the vascular endothelium that promotes essential leukocyte rolling in the early inflammatory response by binding to glycoproteins containing the tetrasaccharide sialyl Lewisx(...E-selectin is a cell-adhesion molecule of the vascular endothelium that promotes essential leukocyte rolling in the early inflammatory response by binding to glycoproteins containing the tetrasaccharide sialyl Lewisx(sLex).Efficient leukocyte recruitment under vascular flow conditions depends on an increased lifetime of E-selectin/ligand complexes under tensile force in a so-called catch-bond binding mode.Co-crystal structures of a representative fragment of the extracellular E-selectin region with sLex and a glycomimetic antagonist thereof reveal an extended E-selectin conformation,which is identified as a high-affinity binding state of E-selectin by molecular dynamics simulations.Small-angle X-ray scattering experiments demonstrate a direct link between ligand binding and E-selectin conformational transition under static conditions in solution.This permits tracing a series of concerted structural changes connecting ligand binding to conformational stretching as the structural basis of E-selectin catch-bond-mediated leukocyte recruitment.The detailed molecular view of the binding site paves the way for the design of a new generation of selectin antagonists.This is of special interest,since their therapeutic potentialwas recently demonstrated with the pan-selectin antagonists GMI-1070(Rivipansel).展开更多
Background:Power in the gamma band EEG increases during saccades in normal subjects.Objective:To develop a potential method to quantify signs of cortical responsiveness in persistent vegetative state(PVS)we quantified...Background:Power in the gamma band EEG increases during saccades in normal subjects.Objective:To develop a potential method to quantify signs of cortical responsiveness in persistent vegetative state(PVS)we quantified gamma range EEG in association with conjugate slow ballistic eye movements(SBEM).Methods:The EEG and the simultaneous electro-oculogram were recorded in 14(8F/6M)PVS patients.Clinical scoring was based on the Glasgow Coma Scale(GCS)and Coma Rating Scale(CRS).The Wavelet Transform,followed by Hilbert transform was applied to the EEG and gamma power distribution was quantified relative to the timing of an eye movement.We correlated the clinical and the neurophysiological measures.Results:Gamma activity was present in all PVS patients.Its power was modulated in association with eye movements only in less severely affected patients,with minimum power prior to,and maximum power during the eye movement.In severely affected patients there was no evidence of a temporal relationship between gamma power and the phase of the eye movement.Conclusions:Detecting changes in the time course of gamma power in relation to conjugate ballistic eye movements provides a quantitative neurophysiological method for prospective longitudinal studies to explore if the preservation of this CNS function relates to the potential for recovery in PVS patients.展开更多
A 9- year-old girl presented with a 2- year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical find...A 9- year-old girl presented with a 2- year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical findings. Owing to parental concern, a biopsy was performed, which revealed numerous bacteria as well as Medlar bodies overlying the nail bed with no evidence of a nevomelanocytic lesion. To our knowledge, this is the first report of Medlar bodies causing pigmented streaks in the toenails.展开更多
文摘DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.
文摘The ideal functional electrical stimulation (FES) system requires a mathematical model to provide feedforward control of the stimulation parameters such that they are optimal for different individuals across a range of physiological condi tions, muscles, and tasks. Recently we tested and validated such a model using a ble-bodied subjects. The purpose of this study was to determine whether this mo del applied to persons with spinal cord injuries (SCI). To this end, the isometr ic force responses of the paralyzed quadriceps femoris muscles of 14 adolescents and young adults were tested. For each subject, the force responses to two six -pulse stimulation trains were used to identify the parameter values of the mod el and then the model was used to predict the force responses to three train pat terns across a range of frequencies in both a nonfatigued and fatigued condition . The intraclass correlation coefficients (ICCs) between the experimental and pr edicted force-time integrals and peak forces were above 0.90 for 12 of the 13 s timulation trains tested in the nonfatigued condition and all 13 trains tested i n the fatigued condition. The success of our model with SCI subjects leads us to believe that our model may be useful for designing optimal stimulation paramete rs for standing and ambulation in patients who use FES.
基金supported by the Swiss National Science Foundation(grant number 200020_129935 and R’EQUIP 145023).
文摘E-selectin is a cell-adhesion molecule of the vascular endothelium that promotes essential leukocyte rolling in the early inflammatory response by binding to glycoproteins containing the tetrasaccharide sialyl Lewisx(sLex).Efficient leukocyte recruitment under vascular flow conditions depends on an increased lifetime of E-selectin/ligand complexes under tensile force in a so-called catch-bond binding mode.Co-crystal structures of a representative fragment of the extracellular E-selectin region with sLex and a glycomimetic antagonist thereof reveal an extended E-selectin conformation,which is identified as a high-affinity binding state of E-selectin by molecular dynamics simulations.Small-angle X-ray scattering experiments demonstrate a direct link between ligand binding and E-selectin conformational transition under static conditions in solution.This permits tracing a series of concerted structural changes connecting ligand binding to conformational stretching as the structural basis of E-selectin catch-bond-mediated leukocyte recruitment.The detailed molecular view of the binding site paves the way for the design of a new generation of selectin antagonists.This is of special interest,since their therapeutic potentialwas recently demonstrated with the pan-selectin antagonists GMI-1070(Rivipansel).
文摘Background:Power in the gamma band EEG increases during saccades in normal subjects.Objective:To develop a potential method to quantify signs of cortical responsiveness in persistent vegetative state(PVS)we quantified gamma range EEG in association with conjugate slow ballistic eye movements(SBEM).Methods:The EEG and the simultaneous electro-oculogram were recorded in 14(8F/6M)PVS patients.Clinical scoring was based on the Glasgow Coma Scale(GCS)and Coma Rating Scale(CRS).The Wavelet Transform,followed by Hilbert transform was applied to the EEG and gamma power distribution was quantified relative to the timing of an eye movement.We correlated the clinical and the neurophysiological measures.Results:Gamma activity was present in all PVS patients.Its power was modulated in association with eye movements only in less severely affected patients,with minimum power prior to,and maximum power during the eye movement.In severely affected patients there was no evidence of a temporal relationship between gamma power and the phase of the eye movement.Conclusions:Detecting changes in the time course of gamma power in relation to conjugate ballistic eye movements provides a quantitative neurophysiological method for prospective longitudinal studies to explore if the preservation of this CNS function relates to the potential for recovery in PVS patients.
文摘A 9- year-old girl presented with a 2- year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical findings. Owing to parental concern, a biopsy was performed, which revealed numerous bacteria as well as Medlar bodies overlying the nail bed with no evidence of a nevomelanocytic lesion. To our knowledge, this is the first report of Medlar bodies causing pigmented streaks in the toenails.
