Spinal cord injury(SCI)population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles,extensive muscle atrophy,infiltration of intramuscular fat and formation of fibrous t...Spinal cord injury(SCI)population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles,extensive muscle atrophy,infiltration of intramuscular fat and formation of fibrous tissue.These morphological changes may put individuals with SCI at higher risk for developing other diseases such as various cardiovascular diseases,diabetes,obesity and osteoporosis.Currently,there is no available rehabilitation intervention to rescue the muscles or restore muscle size in SCI individuals with lower motor neuron denervation.We,hereby,performed a review of the available evidence that supports the use of electrical stimulation in restoration of denervated muscle following SCI.Long pulse width stimulation(LPWS)technique is an upcoming method of stimulating denervated muscles.Our primary objective is to explore the best stimulation paradigms(stimulation parameters,stimulation technique and stimulation wave)to achieve restoration of the denervated muscle.Stimulation parameters,such as the pulse duration,need to be 100–1000 times longer than in innervated muscles to achieve desirable excitability and contraction.The use of electrical stimulation in animal and human models induces muscle hypertrophy.Findings in animal models indicate that electrical stimulation,with a combination of exercise and pharmacological interventions,have proven to be effective in improving various aspects like relative muscle weight,muscle cross sectional area,number of myelinated regenerated fibers,and restoring some level of muscle function.Human studies have shown similar outcomes,identifying the use of LPWS as an effective strategy in increasing muscle cross sectional area,the size of muscle fibers,and improving muscle function.Therefore,displaying promise is an effective future stimulation intervention.In summary,LPWS is a novel stimulation technique for denervated muscles in humans with SCI.Successful studies on LPWS of denervated muscles will help in translating this stimulation technique to the clinical le展开更多
A sloping semisolid rheo-rolling process of Mg-3Sn-1Mn alloy was developed, and the effects of process parameters on the microstructure and mechanical properties of Mg-3Sn-lMn alloy strip were studied. The results sho...A sloping semisolid rheo-rolling process of Mg-3Sn-1Mn alloy was developed, and the effects of process parameters on the microstructure and mechanical properties of Mg-3Sn-lMn alloy strip were studied. The results show that the primary grain average diameter of the strip increases with the increase of the roll speed. The primary grain average diameter decreases firstly and then increases with the increase of the vibration frequency, and the tensile strength and elongation of the strip increase firstly and then decrease with the increase of the vibration frequency. The primary grain average diameter increases with the increase of casting temperature, and the tensile strength and elongation of the strip decrease correspondingly. When the casting temperature is 670℃, the roll speed is 52 mm/s, and the vibration frequency is 60 Hz, Mg-3Sn-1Mn alloy strip with good properties is produced. The mechanical properties of the present product are higher than those of Mg-3Sn-lMn alloy casting with the addition of 0.87% Ce （mass fraction）.展开更多
文摘Spinal cord injury(SCI)population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles,extensive muscle atrophy,infiltration of intramuscular fat and formation of fibrous tissue.These morphological changes may put individuals with SCI at higher risk for developing other diseases such as various cardiovascular diseases,diabetes,obesity and osteoporosis.Currently,there is no available rehabilitation intervention to rescue the muscles or restore muscle size in SCI individuals with lower motor neuron denervation.We,hereby,performed a review of the available evidence that supports the use of electrical stimulation in restoration of denervated muscle following SCI.Long pulse width stimulation(LPWS)technique is an upcoming method of stimulating denervated muscles.Our primary objective is to explore the best stimulation paradigms(stimulation parameters,stimulation technique and stimulation wave)to achieve restoration of the denervated muscle.Stimulation parameters,such as the pulse duration,need to be 100–1000 times longer than in innervated muscles to achieve desirable excitability and contraction.The use of electrical stimulation in animal and human models induces muscle hypertrophy.Findings in animal models indicate that electrical stimulation,with a combination of exercise and pharmacological interventions,have proven to be effective in improving various aspects like relative muscle weight,muscle cross sectional area,number of myelinated regenerated fibers,and restoring some level of muscle function.Human studies have shown similar outcomes,identifying the use of LPWS as an effective strategy in increasing muscle cross sectional area,the size of muscle fibers,and improving muscle function.Therefore,displaying promise is an effective future stimulation intervention.In summary,LPWS is a novel stimulation technique for denervated muscles in humans with SCI.Successful studies on LPWS of denervated muscles will help in translating this stimulation technique to the clinical le
基金Project(51222405) supported by the National Science Foundation of Outstanding Young Scholars of ChinaProject(51034002) supported by the National Natural Science Foundation of China+1 种基金Project(132002) supported by the Fok Ying Tong Education FoundationProject (2011CB610405) supported by the National Basic Research Program of China
文摘A sloping semisolid rheo-rolling process of Mg-3Sn-1Mn alloy was developed, and the effects of process parameters on the microstructure and mechanical properties of Mg-3Sn-lMn alloy strip were studied. The results show that the primary grain average diameter of the strip increases with the increase of the roll speed. The primary grain average diameter decreases firstly and then increases with the increase of the vibration frequency, and the tensile strength and elongation of the strip increase firstly and then decrease with the increase of the vibration frequency. The primary grain average diameter increases with the increase of casting temperature, and the tensile strength and elongation of the strip decrease correspondingly. When the casting temperature is 670℃, the roll speed is 52 mm/s, and the vibration frequency is 60 Hz, Mg-3Sn-1Mn alloy strip with good properties is produced. The mechanical properties of the present product are higher than those of Mg-3Sn-lMn alloy casting with the addition of 0.87% Ce （mass fraction）.
