Since COVID-19 infection,many infected patients have developed multiple systemic symptoms that persist long after 3 months of infection,which is called Long COVID.Numerous studies have shown that fatigue is the most common symptom among the many symptoms of Long COVID that has severely impacted the quality of their life.Therefore,it is particularly important to understand the mechanisms by which Long COVID causes fatigue symptoms.This article summarizes the possible mechanisms of Long COVID fatigue,including immune response,oxidative stress,and affecting the central nervous system,by combing through the relevant literature,aiming to increase clinical awareness of fatigue induced by Long COVID and to provide certain ideas for its treatment.

Objective:To evaluate the homogenization effect of standardized residency training base of internal medicine and to provide reference for further improving the standardized residency training system.Methods:Taking all "unit residents" who took part in the standardized residency training test of Beijing resident physicians in 2015 and 2016 as the research objects, the self-assessment questionnaire survey of resident competency was carried out to analyze the training effect on competency. SPSS 21.0 was used to statistically analyze the collected data.Results:There are differences in self-assessment scores among the four system bases. From high to low, the overall self-assessment score are PUMCH, CCMU, the military, PUHSC. Among the eight abilities, the abilities of teaching and scientific research were the lowest.Conclusion:The training effect of Beijing internal medicine training base has not achieved homogenization. In order to improve the comprehensive ability of residents, it is suggested to strengthen the weak links in the standardized residency training from three aspects: teachers, training process and increasing support.

Objective To establish a reasonable evaluation system of the training effect of residents and professional master degree graduates in order to meet the needs of the construction of medical education system.Methods A questionnaire study had been conducted by stratified sampling to evaluate the abilities of the residents and medical professional degree graduates who had finished residency training in Beijing from 2015 to 2016.The trainees were evaluated by themselves,their colleagues and patients they had dealt with.Results The results showed that 95.29％ of the trainees and 99.00％ of their colleagues or patients thought that the overall abilities of the trainees were "excellent" or "better",and the evaluation results of all kinds of personnel above were consistent.Statistical analysis showed that some of the sub items of each ability index were evaluated better than the others,such as professional ethics,team cooperation ability and interpersonal communication ability,while some of the sub abilities need to be improved such as the information and management ability as well as teaching and research ability.The comparative analysis indicated that the postgraduates were superior to the residents in abilities of clinical diagnosis and treatment,information and management ability,and teaching and research ability.Conclusion The study showed that the training effect of residents and professional degree graduates had met the basic requirements,but the comprehensive quality and innovation ability needs to be promoted.The combination of degree education and resident training helps to cultivate the comprehensive ability of medical talents.