RESUMEN
Nearly half of the elements in the periodic table are extracted, refined, or plated using electrodeposition in high-temperature melts. However, operando observations and tuning of the electrodeposition process during realistic electrolysis operations are extremely difficult due to severe reaction conditions and complicated electrolytic cell, which makes the improvement of the process very blind and inefficient. Here, we developed a multipurpose operando high-temperature electrochemical instrument that combines operando Raman microspectroscopy analysis, optical microscopy imaging, and a tunable magnetic field. Subsequently, the electrodeposition of Ti-which is a typical polyvalent metal and generally shows a very complex electrode process-was used to verify the stability of the instrument. The complex multistep cathodic process of Ti in the molten salt at 823 K was systematically analyzed by a multidimensional operando analysis strategy involving multiple experimental studies, theoretical calculations, etc. The regulatory effect and its corresponding scale-span mechanism of the magnetic field on the electrodeposition process of Ti were also elucidated, which would be inaccessible with existing experimental techniques and is significant for the real-time and rational optimization of the process. Overall, this work established a powerful and universal methodology for in-depth analysis of high-temperature electrochemistry.
RESUMEN
OBJECTIVE: To assess the medium- and long-term effectiveness of selective posterior rhizotomy (SPR) for spastic cerebral palsy. METHODS: A retrospective analysis was made on 27 patients with spastic cerebral palsy undergoing SPR between January 1997 and January 2008, whose data were complete with more than 5 years follow-up. There were 14 males and 13 females with an average age of 10.1 years (range, 4-19 years). All patients had simple spastic cerebral palsy, including 17 cases of bilateral spastic palsy and 10 cases of unilateral spastic palsy. The muscle strength, muscle tone, ambulatory function, the sharp foot and crossing-feet, knee jerk, ankle clonus, and Babinski's sign were evaluated before and after operation. RESULTS: All the patients were followed up 5-16 years (mean, 9.6 years). No obvious limitation of lumbar flexion, extension and lateral flexion, spondylolisthesis, kyphosis, and other deformities occurred. At last follow-up, the muscle strength of hip extensors, hip flexors, and knee extensors were significantly increased when compared with preoperative ones (P < 0.05); but no significant difference was found in the muscle strength of hip abductors, hip adductors, knee flexors, plantar extensors, and plantar flexors (P > 0.05). Abnormal increased muscle tone of hip flexors, hip adductors, knee flexors, and plantar flexors was declined in different degrees in all patients, showing significant differences when compared with preoperative ones (P < 0.05); but no significant difference was found in hip extensors, hip abductors, knee extensors, and plantar extensors (P > 0.05). At last follow-up, the status of toe steps and crossing-feet disappeared without recurrence for a long time. Sthenic knee jerk was eliminated, but there were several patients also keeping the active knee jerk, showing significant difference when compared with preoperative ones (Z= -7.404, P=0.000). The results of Babinski's sign were negative in 31 sides and positive in 13 sides, showing significant difference when compared with preoperative ones (Z= -6.897, P=0.000). No sharp foot or crossing-feet was observed. And ambulation ability was significantly improved after operation (Z= -4.111, P=0.000). CONCLUSION: SPR is very effective in decreasing the muscle tone and improving the motor function without recurrence in long-term.