Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord...Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord in vivo. Diffusion tensor imaging technology is a sensitive method to diagnose spinal cord injury; fiber tractography visualizes the white matter fibers, and directly displays the structural integrity and resultant damage of the fiber bundle. At present, diffusion tensor imaging is restricted to brain examinations, and is rarely applied in the evaluation of spinal cord injury. This study aimed to explore the fractional anisotropy and apparent diffusion coefficient of diffusion tensor magnetic resonance imaging and the feasibility of diffusion tensor tractography in the evaluation of complete spinal cord injury in rats. The results showed that the average combined scores were obviously decreased after spinal cord transection in rats, and then began to increase over time. The fractional anisotropy scores after spinal cord transection in rats were significantly lower than those in normal rats （P 〈 0.05）; the apparent diffusion coefficient was significantly increased compared with the normal group （P 〈 0.05）. Following spinal cord transection, fractional anisotropy scores were negatively correlated with apparent diffusion coefficient values （r = -0.856, P 〈 0.01）, and positively correlated with the average combined scores （r = 0.943, P 〈 0.01）, while apparent diffusion coefficient values had a negative correlation with the average combined scores （r = -0.949, P 〈 0.01）. Experimental findings suggest that, as a non-invasive examination, diffusion tensor magnetic resonance imaging can provide qualita- tive and quantitative information about spinal cord injury. The fractional anisotropy score and apparent diffusion coefficient have a good correlation with the average combined scores, which reflect functional recovery after spinal cord injury.展开更多
The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a P...The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a Pt electrode proceeds in two steps: Cu(II) + evelence Cu(I); Cu(I) + e velence Cu. The reduction potential of Cu(II) in DMSO solution is morenegative than that in CH_3OH solution, and the diffusion coefficient of Cu(II) ion in DMSO solutionis larger than that in CH_3OH solution because the polarity of DMSO is larger than that of CH_3OHobservably and has a stronger solvating power.展开更多
The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-...The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-electron process, that is： Hf（IV） ＋ 2e→Hf（II） and Hf（II） ＋ 2e- →Hf, and the electrochemical reduction of Hf（IV） pro- cess was diffusion-controlled. The diffusion coefficients were calculated at several temperatures, and the results obey the Arrhenius law. According to the relationship oflnD versus 1/T, the corresponding activation energy was determined to be 158.8 kJ.mol- x. The square wave voltammetry results further confirm the reduction mechanism of hafnium.展开更多
基金financially supported by a grant from the Shaanxi Provincial Science and Technology Research and Development Project,No.2013K12-20-08
文摘Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord in vivo. Diffusion tensor imaging technology is a sensitive method to diagnose spinal cord injury; fiber tractography visualizes the white matter fibers, and directly displays the structural integrity and resultant damage of the fiber bundle. At present, diffusion tensor imaging is restricted to brain examinations, and is rarely applied in the evaluation of spinal cord injury. This study aimed to explore the fractional anisotropy and apparent diffusion coefficient of diffusion tensor magnetic resonance imaging and the feasibility of diffusion tensor tractography in the evaluation of complete spinal cord injury in rats. The results showed that the average combined scores were obviously decreased after spinal cord transection in rats, and then began to increase over time. The fractional anisotropy scores after spinal cord transection in rats were significantly lower than those in normal rats （P 〈 0.05）; the apparent diffusion coefficient was significantly increased compared with the normal group （P 〈 0.05）. Following spinal cord transection, fractional anisotropy scores were negatively correlated with apparent diffusion coefficient values （r = -0.856, P 〈 0.01）, and positively correlated with the average combined scores （r = 0.943, P 〈 0.01）, while apparent diffusion coefficient values had a negative correlation with the average combined scores （r = -0.949, P 〈 0.01）. Experimental findings suggest that, as a non-invasive examination, diffusion tensor magnetic resonance imaging can provide qualita- tive and quantitative information about spinal cord injury. The fractional anisotropy score and apparent diffusion coefficient have a good correlation with the average combined scores, which reflect functional recovery after spinal cord injury.
基金This project is financially supported by the Scientific Commission Foundation of Guangzhou City (No. 2001-J-015-01)
文摘The cyclic voltammetry and the potential-time curve after galvanostaticelectrolysis were used to study the electrode processes of Cu(II) in CH_3OH solution and DMSOsolution. The electroreduction of Cu(II) to Cu on a Pt electrode proceeds in two steps: Cu(II) + evelence Cu(I); Cu(I) + e velence Cu. The reduction potential of Cu(II) in DMSO solution is morenegative than that in CH_3OH solution, and the diffusion coefficient of Cu(II) ion in DMSO solutionis larger than that in CH_3OH solution because the polarity of DMSO is larger than that of CH_3OHobservably and has a stronger solvating power.
基金financially supported by the National Natural Science Foundation of China(No.51204021)the National Science and Technology Plan of China(No.2012BAB10B10)
文摘The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-electron process, that is： Hf（IV） ＋ 2e→Hf（II） and Hf（II） ＋ 2e- →Hf, and the electrochemical reduction of Hf（IV） pro- cess was diffusion-controlled. The diffusion coefficients were calculated at several temperatures, and the results obey the Arrhenius law. According to the relationship oflnD versus 1/T, the corresponding activation energy was determined to be 158.8 kJ.mol- x. The square wave voltammetry results further confirm the reduction mechanism of hafnium.
