Batch and fixed-bed column biosorption of manganese ion by sargassum filipendula

This paper presents experimental data of the biosorption of manganese onto Sargassum filipendula in both batch and fixed-bed column systems. Batch equilibrium data were used for nonlinear fittings of the Langmuir and Freundlich isotherms. A mathematical model based on mass balances in the fluid and in the sorbent was applied to represent the experimental fixed-bed column data. The utilization of isotherm parameters from the batch experiments in the breakthrough model implied a significant mismatch in relation to the laboratory data. Alternatively, additional fixed-bed column data provided new parameters for the isotherm evaluation, and the corresponding simulated profile of the breakthrough curve reached better agreement to the experimental results.

Clinical Efficacy of Implant Removal after Posterior Spinal Arthrodesis with Pedicle Screw Fixation for the Thoracolumbar Burst Fractures / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical efficacy of implant removal by analyzing the radiological changes after posterior spinal stabilization in patients with thoracolumbar burst fractures. MATERIALS AND METHODS: Fifty-eight patients, who received surgical treatment after a thoracolumbar burst fracture with at least a two year follow-up, were enrolled in this study. An evaluation of the clinical results was based on the VAS score to examine degree of pain and discomfort. The evaluation of the radiological results was performed by measuring the changes in the kyphotic angle of the fractured vertebral bodies and the severity of the collapse of the anterior vertebral height taken after the injury, after fusion and after metal removal on the plain lateral radiograph. RESULTS: The VAS score on pain and discomfort after removing the implants showed a significant decrease from 6.5 to 3.2 and from 5.6 to 2.8, respectively. Overall, the kyphotic angle after removing the implants increased by 3.7 degrees, whereas the anterior height of the fractured vertebral body after removing the implant decreased by 1.5% in correction. CONCLUSION: The removal of implants after posterior arthrodesis in thoracolumbar burst fractures can be performed effectively to relieve the pain and restore flexibility but can result in the progression of kyphosis. However careful consideration should be made before removing an implant in cases of severe initial damage.