BACKGROUND: It is of great significance to study the resilience of articular cartilage for human daily routine and their match quality. OBJECTIVE: To analyze the micromechanical properties of articular cartilage resilience under different loads and at time points. METHODS: The swine cartilage samples coated with tracers were compressed using the MTF-100 tensile machine, and the cartilage compression and resilience were recorded by CCD. Images were processed using digital image correlation technology.RESULTS AND CONCLUSION: During resilience, the strain value on the superficial surface of the cartilage was decreased most, successively followed by the middle layer and the deep layer, while the time of a decrease from 20%, 10% and 6% to 3% was similar. The longer the resilience time was, the more slowly the strain changed in different layers of the cartilage, but the ultimate strain was less than 1%. On the same layer under different compressive stress, the larger load caused faster strain change firstly, and then the smaller load brought about faster strain change. The effect of different continuous compressive time on the same layer of cartilage was similar with the load. These results showed that 90% resilience of the articular cartilage occurred within the first 15 minutes. The mechanical resilience of different layers of the articular cartilage has a close relationship with the loading and the loading time, and both compressive time and loading do harm to the resilience of articular cartilage. Besides, the cartilage will rebound to the state before compression.

Objective: To analyze the information about coronavirus disease 2019 (COVID-19) on WeChat official accounts of centers for disease control and prevention (CDCs) in Zhejiang Province from January 20 to February 5,2020,so as to provide reference for improving the effects of health communication by WeChat official accounts. Methods: The number,content and pageview of the information about COVID-19 on WeChat official accounts of one provincial and eleven municipal CDCs from January 20 to February 5 were collected and analyzed. The number of new followers and WeChat communication power index (WCI) were employed to evaluate the communication effect. Results: By February 5,those WeChat public official accounts pushed 629 pieces of information about COVID-19. The pageviews were 3 713 428 in total and 5 903.70 on average. There were totally 633 008 followers,including 110 341 new followers which contributed to a growth rate of 21.11%. The average WCI was 677.81. The WCIs of eight official accounts were higher than 500,with “Zhejiang Health Education” the highest (1 021.95). The daily pageviews peaked on January 20,21,25 and 31. Among the top 15 pieces of information in pageviews,there were 7 pieces for epidemic announcements,3 pieces for popular science and 5 pieces for behavioral intervention. Conclusions The WeChat official accounts of CDCs in Zhejiang Province pushed the information about COVID-19 in line with the progress of the epidemic and the demand of the public,leading to a higher attention and better communication effect.