Vibration training and quadriceps muscle strength in soccer players' knee joints

Objective: This paper discusses the effect of vibration training on the strength of knee flexion and extension muscle group of football players. Methods: This test was carried out in a local sports college from January 2021 to January 2022. Taking 22 football playersin the college as an example, the athletes were divided into experimental group and observation group by digital grouping method, with 11 people in each group. The observation group was trained with the conventional lower limb physical training method, but also on the equipment. In the process of the experiment, the researchers will focus on the analysis of vibration training on the knee flexion and extension muscle group of football players, and compare the data and effects of the two groups of athletes. The experiment lasted for eight weeks. Results:The data of the experimental group were better than those of the observation group. Vibration training had a significant effect on improving the muscle strength of knee flexion and extension muscle group of football players, P > 0.05. Conclusion:In this eight-week experiment, the vibration training program with 30Hz frequency and 2mm amplitude can significantly improve the muscle strength of knee flexion and extension muscles of college athletes. Compared with the traditional training method, the vibration training program has more advantages, mainly reflected in the tolerance of athletes. However, there is little difference between the method and the traditional training method in the athlete's explosive power, and no great advantage is seen (AU)

Evolutionary game analysis of forestry carbon sink trading model under blockchain technology.

As a new balanced economy, the green economy guides the upgrade and transformation of industrial structures based on the original concept of sustainable development. Reducing carbon emissions is indispensable for achieving better and faster green economic development. From a functional perspective, forestry carbon sinks have good carbon sequestration potential and have positive attributes, such as climate regulation and biodiversity maintenance, for the entire ecosystem. To promote the continuous development of forestry carbon sink trading in China, blockchain, a new technology with several advantages such as traceability, supervision, and tamper-proofness, has emerged, which creates a good market trading environment and has made a breakthrough in the trading mode. If forestry carbon sink trading is effectively supported, organic combinations and simultaneous synergistic development can be conducted, which will open new avenues for the carbon sink economy. In this study, a game model of the forest carbon sink trading mode under blockchain technology was constructed from the perspective of traders, and influential factors, such as the carbon sink available for sale by the supply side and the demand side's perspective towards emission reduction, were considered. Subsequently, the MATLAB R2020b software was used to conduct a simulation analysis of the transactions, thereby showing the evolutionary path of the game between the two sides and the influence mechanism of the addition of blockchain technology on the evolution trajectory of the demand-side decision. The findings indicate that, from the perspective of participating traders, the inclusion of blockchain technology in forestry carbon sink trading resulted in positive effects. Moreover, the greater the probability that the carbon sinks available for sale in the market can meet the demand, the more likely the demand side is to participate in the transaction.

How many COVID-19 cases could have been prevented in the US if its interventions were as effective as those in China and South Korea?

The COVID-19 [1] pandemic has forced governments to take measures to contain the spread of the disease [2]; however, the effects have varied significantly from one country to another contingent on governments responses. Countries that have flattened their coronavirus curves prove that interventions can bring COVID-19 under control. These achievements hold lessons, such as the strict social distancing and coordinated efforts of all government levels in China and massive testing in South Korea, for other countries battling the coronavirus around the world. In this work, we attempt to estimate how many COVID-19 cases could have been prevented in the United States (US) when compared with the USs actual number of cases assuming that on a certain date, the US took China-like or South Korea-like interventions and that these interventions would have been as effective in the US as in China and South Korea. We found that if that date was at the early stage of the outbreak (March 10), more than 99% (1.15 million) fewer infected cases could be expected by the end of the epidemic. This number decreases to 66.03% and 73.06% fewer infected cases with the China-like scenario and the South Korea-like scenario, respectively, if actions were taken on April 1, highlighting the need to respond quickly and effectively to fight the virus. Furthermore, we found that although interventions in both China and South Korea allowed the COVID-19 outbreak to be managed, the epidemic could still oscillate without strict large-scale lockdown measures, as shown in South Korea. Our results demonstrate that early effective interventions can save considerably more people from infection and provide a worldwide alert regard the need for swift response.

Serial interval and generation interval for respectively the imported and local infectors estimated using reported contact-tracing data of COVID-19 in China

BackgroundsThe emerging virus, COVID-19, has caused a massive out-break worldwide. Based on the publicly available contact-tracing data, we identified 337 transmission chains from 10 provinces in China and estimated the serial interval (SI) and generation interval (GI) of COVID-19 in China. MethodsInspired by possibly different values of the time-varying reproduction number for the imported cases and the local cases in China, we divided all transmission events into three subsets: imported (the zeroth generation) infecting 1st-generation locals, 1st-generation locals infecting 2nd-generation locals, and others transmissions among 2+ generations. The corresponding SI (GI) is respec-tively denoted as [Formula], and [Formula]. A Bayesian approach with doubly interval-censored likelihood is employed to fit the lognormal, gamma, and Weibull distribution function of the SI and GI using the identified 337 transmission chains. FindingsIt is found that the estimated [Formula], and [Formula], thus overall both SI and GI decrease when generation increases.

Quantitative evaluation of microstructural changes of brain nuclei in Wilson's disease with neurite orientation dispersion and density imaging / 中国医学影像技术

Objective To investigate the value of neurite orientation dispersion and density imaging (NODDI) in quantitative evaluation of the microstructural changes in basal ganglia and thalamus in Wilson's disease (WD) patients,and to assess the diagnostic efficacy of NODDI.Methods Totally 27 WD patients (WD group) and 26 age-and sex-matched controls (control group) were enrolled.All subjects underwent MR scanning with NODDI.Parameters of NODDI,including intracellular volume fraction (Vic),orientation dispersion index (ODI) and isotropic volume fraction (Viso) of bilateral caudate nucleus,globus pallidus,putamen and thalamus were compared between the 2 groups.Correlation analysis was performed between each parameter of NODDI and clinical Young scores.Random Forest model was used to assess the relative importance of each parameter and to evaluate the diagnostic efficacy.Results The Vic and ODI of bilateral caudate nucleus,globus pallidus and putamen in WD patients were significantly lower than those in normal controls (all P＜0.05),while Viso was significantly higher than that in normal controls (all P＜0.05).The Vic of bilateral thalamus was lower,while Viso was higher in WD patients than those in normal controls (all P＜0.05),and ODI had no significant difference between the 2 groups (P=0.055).In WD patients,Vic and ODI of bilateral caudate nucleus,globus pallidus and putamen were negatively correlated with clinical Young scores.Viso of globus pallidus and putamen were positively correlated with clinical scores.The prediction accuracy of NODDI was 96.23％,and the area under ROC curve was 0.96.Conclusion NODDI can effectively evaluate changes in microstructures and metabolism during copper deposition in WD patients,and it may be useful in detecting changes of brain deep nuclei and assessing the progression of WD.