Preparation and application of a novel bioflocculant by two strains of Rhizopus sp. using potato starch wastewater as nutrilite.

A complex bioflocculant MBF917 was prepared by Rhizopus sp. M9 and M17 using potato starch wastewater (PSW) as nutrilite, and its flocculation characteristics of treating PSW were studied. Culture conditions of the two strains were optimized, and flocculating conditions of the bioflocculant for treating PSW were also investigated. The optimal and economical culture conditions were determined as COD of about 1600 mg/L, 0.3 g/L urea and 0.04 g/L potassium dihydrogen phosphate, with no need of adding carbon sources or adjusting pH. When the bioflocculant was used to flocculate PSW, the optimal dosage was 0.1 mL/L with addition of 5 mL/L 10% CaCl2 as coagulant aid, and there was no need to adjust pH. After flocculation, COD and turbidity removal rates of the PSW could reach 54.09% and 92.11%, respectively, and 1.1g/L proteic substance was recycled from the PSW as a byproduct that could be used for animal feed.

Subthalamic nucleus stimulation for Parkinson's disease preferentially improves akinesia of proximal arm movements compared to finger movements.

Deep brain stimulation of the subthalamic nucleus (STN-DBS) reduces akinesia in Parkinson's disease but its impact on fine motor functions was unknown. We assessed the effects of DBS and a levodopa (L-dopa) test on the timing of the precision grip in 18 patients. Improvement on UPDRS-items reflecting hand functions and the shortening of the first phases of the precision grip were more distinct in the L-dopa test than in the pure STN-DBS condition. Other akinesia items and the time for build-up of lifting force were equally improved in both conditions. This suggests that routine STN-DBS might not be equally effective on all aspects of fine motor functions.

Dyskinesias and grip control in Parkinson's disease are normalized by chronic stimulation of the subthalamic nucleus.

Deep-brain stimulation of the subthalamic nucleus appears to reduce levodopa-induced dyskinesias, but whether this effect is caused by the reduction of the total levodopa ingestion or represents a direct effect on the motor system is unknown. Precision grip force of grasping movements and levodopa-induced dyskinesias was analyzed in 10 parkinsonian patients before and after 3 months of deep-brain stimulation of the subthalamic nucleus. Peak grip force was abnormally increased before surgery in the off-drug state and, particularly, in the on-drug state (sensitization). This grip force upregulation normalized with chronic deep-brain stimulation in both conditions (desensitization). Peak-dose dyskinesias also improved, and off-dystonia was completely abolished. Mean dosage of dopaminergic drugs was reduced, but force overflow and dyskinesias were equally improved in 2 patients without a reduction. Despite the same single levodopa test dose, force excess and levodopa-induced dyskinesias were drastically reduced after 3 months of deep-brain stimulation of the subthalamic nucleus. This indicates that direct effects of deep-brain stimulation of the subthalamic nucleus on levodopa-induced dyskinesias are likely to occur. Grip force overflow is a promising parameter to study the desensitizing effect of chronic deep-brain stimulation on levodopa-induced dyskinesias.