ABSTRACT
Magnetic Resonance Imaging(MRI)technology can directly show the changes of brain network and explain the central mechanism of Tai Chi remodeling of brain structure and function.In this paper,we collected the domestic and foreign research on the influence of Tai Chi movement on the brain network by using MRI technology,and combed it from the perspective of brain structure and function changes.The results revealed that Tai Chi may promote memory function,cognitive flexibility,inhibitory control,and working memory capacity by remodeling the structure and function of the medial temporal lobe and prefrontal cortex in older adults,which may be a potential central mechanism for Tai Chi to improve memory and cognitive control in the elderly.However,there are some problems in the current research,such as small sample size,insufficient long-term follow-up,and difficult evaluation of exercise intensity.It is necessary to carry out large-sample and long-term detailed research to further verify the current research results.
ABSTRACT
Traditionally, comprehensive laboratorial experiments on newly proposed microfluidic devices are necessary for theoretical validation, technological design, methodological calibration and optimization. Multiple parameters and characteristics, such as the flow rate, particle size, microchannel dimensions, etc., should be studied by controlled trials, which could inevitably result in extensive experiments and a heavy burden on researchers. In this work, a novel numerical model was introduced to simulate particle migration within a complicated double-layered microchannel. Using the hybrid meshing method, the proposed model achieved a significant improvement in meshing quality, and remarkably reduced the required calculation resources at the same time. The robust, efficient and resource-saving numerical model was calibrated and validated with experimental results. Based on this model, 1) the mechanism of microparticle manipulation within the microchannel was revealed; 2) the primary reason for the microparticle focusing failure was investigated; and 3) the optimal microparticle sorting strategy at different flow rates was analyzed. In experiments, the obtained optimal strategy could approach a good sorting performance with a high recovery rate and high concentration ratio in a high-throughput manner. The proposed numerical model shows great potential in mechanism investigation and functional prediction for microfluidic technologies using unconventional designs.