Poly(ethylene glycol)(PEG) coated silver nanowires has been hydrothermally prepared at a very slow rate, in which PEG was used as both a mild capping agent and a weak reductant. As-prepared silver nanowires(SNWs) have been characterized using scanning electron microscopy) and transmission electron microscope), which showed that the SNWs are usually longer than 100 μm and their diameters(each SNW has a uniform thickness) vary mainly in the range of 80～300 nm. Surprisingly, some of these silver nanowires connected) by their two ends to form some close-looped silver nanowires, which hitherto has not been reported elsewhere. The existence of close-looped silver nanowires supports the mechanism that nanowires can evolve from fusion of some nanoparticles and/or shorter nanorods. Careful TEM characterization and selected area electron) diffraction revealed that the silver nanowires kept a five-fold twinned structure, which is opposite to some reports) that a long-time incubation will lead to the disappearance of this twin structure. This work demonstrates the situation that deeper investigation is still needed for understanding the structure transformation of silver) nanowires.

The mutual influence of lead and cadmium ions on “in-situ” bismuth film coated glassy carbon electrode was demonstrated using different concentration target ions by changing ratio between Pb2+ and Cd2+. It is found that the presence of coexisting ions can have an influence on the detection of target ions. Especially for the detection of Cd2+, the existence of Pb2+ can be beneficial for the deposition of Cd due to the more positive deposition potentials. And the analytical performances of Cd2+and Pb2+ were obtained. The detection limit is 0. 5 μg/L towards Pb2+ with a linear range from 1-80 μg/L using 60 s deposition time. The resulting calibration plots of Cd2+ are linear over the range from 1-25 and 30-200 μg/L with the detection limit of 1 μg/L using 120 s deposition time. The bismuth film was finally employed to determine the Pb2+and Cd2+in real sample with good satisfied results.

Objective:To explore the effects of dual task training assisted by a lower limb rehabilitation robot on lower extremity mobility and the walking ability of stroke survivors.Methods:Sixty-one stroke survivors were randomly divided into a control group and an experimental group with 30 in the control group and 31 in the experimental group. In addition to routine exercise training and physical therapy, both groups were given cognitive-motor dual task training 5 times a week for 3 weeks. But only in the experimental group was the dual task training assisted by a lower limb rehabilitation robot. Both groups′ lower limb motor function, walking ability, cognition, balance and ability in the activities of daily living were evaluated before and after the experiment using the Fugl-Meyer lower extremity assessment (FMA-LE), functional ambulation categories (FAC), the digital span test (DST), the Berg Balance Scale (BBS) and the Modified Barthel Index (MBI). Additionally, 6 survivors of a right hemisphere stroke from the experimental group received cognitive-motor dual task training both with and without the robotic assistance alternately. Near-infrared functional brain imaging was applied before and after the intervention, and the functional network connectivity of the resting brains was analyzed.Results:After the intervention the average FMA-LE, FAC, BBS and MBI scores had improved in both groups, with the improvement in the experimental group significantly better than in the control group on average. In terms of cognition there was no significant difference in the DST forward and backward assessment results between the two groups. The analysis of brain network functional connectivity showed that the intensity of functional connectivity between the left prefrontal cortex (PFC) and the left premotor cortex and supplementary motor cortex (PMC/SMA) increased significantly more, on average, after training assisted by the robot.Conclusion:Dual task training with the assistance of a lower limb rehabilitation robot can effectively improve the lower limb motor function, walking, balance and ability in the activities of daily living of stroke survivors. Enhanced functional connection of the PFC and the PMC/SMA in the healthy hemisphere induced by the robot may be the cause.