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OBJECTIVE: A prospective cohort study to evaluate the efficacy of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on freezing of gait (FOG) in patients with advanced Parkinson's disease. METHODS: Patients (n= 10) with advanced Parkinson's disease were surgically implanted with microelectrodes to facilitate STN-DBS. Evaluations of FOG, motor function, activities of daily living and neuropsychological function were carried out in on-medication and off-medication states (with and without levodopa treatment), before surgery and at 6 and 12 months postoperatively. RESULTS: STN-DBS was associated with significant improvement in FOG score and neuropsychological function at both 6 and 12 months postoperatively, compared with preoperatively. Significant postoperative improvements were also observed in motor function and activities of daily living. Daily levodopa dosage was significantly lower at both 6 and 12 months postoperatively. CONCLUSIONS: STN-DBS improved FOG in patients with advanced Parkinson's disease. The significant reduction in levodopa dosage and improvement in neuropsychological function may be the reason for the therapeutic effect seen with STN-DBS.

General equations for lattice contraction and surface stress of fcc nanocrystals are established based on the Laplace−Young equation and a consideration for the size-dependence of the solid−liquid interface energy. The predictions of our equations are in agreement with the experimental results on the measurement of lattice contraction and surface (interface) stress of nanoparticles and thin films and theoretical calculations.

Flexible bearings are critical components of harmonic drives. In service, the corresponding positions of the long and short axes of the inner and outer rings of a flexible bearing regularly change. This leads to a fatigue fracture of the outer ring because of the cyclic alternating load. In this study, a multi-body contact model and a dynamic model were established using ABAQUS to analyze the load spectrum of a flexible bearing and a wave generator. The dynamic analysis results were employed to simulate the fatigue life of the inner and outer rings using nCode-DesignLife. The results show that the inner ring underwent significant fatigue damage at the long-axis position, and the corresponding fatigue life was low. As the damage on the outer ring was due to continuous alternating deformation, the inner and outer surfaces of the outer ring were significantly damaged. Besides, the outer ring underwent fatigue damage prior to the inner ring under the same working conditions. The results provide theoretical references and practical guidance for the design and life estimation of flexible thin-wall bearings.