Repetitive magnetic stimulation has been shown to alter local blood flow of the brain, excite the corticospinal tract and muscle, and induce motor function recovery. We established a rat model of acute spinal cord inj...Repetitive magnetic stimulation has been shown to alter local blood flow of the brain, excite the corticospinal tract and muscle, and induce motor function recovery. We established a rat model of acute spinal cord injury using the modified Allen＇s method. After 4 hours of injury, rat models received repetitive magnetic stimulation, with a stimulus intensity of 35% maximum output intensity, 5-Hz frequency, 5 seconds for each sequence, and an interval of 2 minutes. This was repeated for a total of 10 sequences, once a day, 5 days in a week, for 2 consecutive weeks. After repetitive magnetic stimulation, the number of apoptotic cells decreased, matrix metalloproteinase 9/2 gene and protein expression decreased, nestin expression increased, somatosensory and motor-evoked potentials recovered, and motor function recovered in the injured spinal cord. These findings confirm that repetitive magnetic stimulation of the spinal cord improved the microenvironment of neural regeneration, reduced neuronal apoptosis, and induced neuroprotective and repair effects on the injured spinal cord.展开更多
The influence of Mo content on the microstructure and mechanical properties of the Ti?45Al?5Nb?xMo?0.3Y(x=0.6,0.8,1.0,1.2)alloys was studied using small ingots produced by non-consumable electrode argon arc melting.Th...The influence of Mo content on the microstructure and mechanical properties of the Ti?45Al?5Nb?xMo?0.3Y(x=0.6,0.8,1.0,1.2)alloys was studied using small ingots produced by non-consumable electrode argon arc melting.The results show that smallquantities ofβphase are distributed alongγ/α2lamellar colony boundaries as discontinuous network in the TiAl alloys owing to thesegregation of Mo element.Theγphase forms in the interdentritic microsegregation area when the Mo addition exceeds0.8%.Theβandγphases can be eliminated effectively by subsequent homogenization heat treatment at the temperature above Tα.The evolutionof the strength,microhardness and ductility at different Mo contents under as-cast and as-homogenization treated conditions wasanalyzed,indicating that excessive Mo addition is prone to cause the microsegregation,thus decreasing the strength andmicrohardness obviously,which can be improved effectively by subsequent homogenization heat treatment.展开更多
文摘Repetitive magnetic stimulation has been shown to alter local blood flow of the brain, excite the corticospinal tract and muscle, and induce motor function recovery. We established a rat model of acute spinal cord injury using the modified Allen＇s method. After 4 hours of injury, rat models received repetitive magnetic stimulation, with a stimulus intensity of 35% maximum output intensity, 5-Hz frequency, 5 seconds for each sequence, and an interval of 2 minutes. This was repeated for a total of 10 sequences, once a day, 5 days in a week, for 2 consecutive weeks. After repetitive magnetic stimulation, the number of apoptotic cells decreased, matrix metalloproteinase 9/2 gene and protein expression decreased, nestin expression increased, somatosensory and motor-evoked potentials recovered, and motor function recovered in the injured spinal cord. These findings confirm that repetitive magnetic stimulation of the spinal cord improved the microenvironment of neural regeneration, reduced neuronal apoptosis, and induced neuroprotective and repair effects on the injured spinal cord.
基金Project(51275132)supported by the National Natural Science Foundation of ChinaProject(2008RFQXG040)supported by the Youth Science and Technology Project of Harbin,China
文摘The influence of Mo content on the microstructure and mechanical properties of the Ti?45Al?5Nb?xMo?0.3Y(x=0.6,0.8,1.0,1.2)alloys was studied using small ingots produced by non-consumable electrode argon arc melting.The results show that smallquantities ofβphase are distributed alongγ/α2lamellar colony boundaries as discontinuous network in the TiAl alloys owing to thesegregation of Mo element.Theγphase forms in the interdentritic microsegregation area when the Mo addition exceeds0.8%.Theβandγphases can be eliminated effectively by subsequent homogenization heat treatment at the temperature above Tα.The evolutionof the strength,microhardness and ductility at different Mo contents under as-cast and as-homogenization treated conditions wasanalyzed,indicating that excessive Mo addition is prone to cause the microsegregation,thus decreasing the strength andmicrohardness obviously,which can be improved effectively by subsequent homogenization heat treatment.
