As a"double-edged sword"in emerging medical science and technology,medical digital twins not only bring good news to clinical diagnosis and treatment,but also have a certain impact on the medical ethics system.This paper mainly discussed the ethical risks and challenges involved in the application of digital twins technology in the medical field,such as the scientificity and effectiveness of simulation experimental results,the autonomy of both doctors and patients,issues of privacy and life safety,and potential social injustice.Starting from the four principles of bioethics,such as respect,benefit,non-harm,and justice,this paper analyzed the current situation and explored prevention and treatment countermeasures or suggestions for solving the ethical issues of medical digital twins,with a view to achieving timely,accurate,and effective detection,prevention,and control,to better promote the rational development,innovative application,and healthy development of digital twins technology in the medical field.

ObjectiveCOVID-19 vaccination is critical for pandemic control， especially in the elderly. Compared with developed countries， the rate of full vaccination and booster vaccination for the elderly in China is low， making it urgent to accelerate the process of vaccination for the elderly in China. MethodsThis study summarizes the policy experiences of the United Kingdom， the United States， Singapore， and South Korea by sorting relevant literature and government websites， analyzes the current performance and reasons for COVID-19 vaccination among the elderly in China， and explores strategic suggestions for improving COVID-19 vaccination in the elderly in terms of vaccination priority groups， service provision， and vaccination intention. ResultsIt is important to vaccination rate for the elderly in China by focusing on the priority vaccination population， establishing a permanent mechanism based on the family doctor system， and increasing the willingness to vaccinate. ConclusionContinued reinforcement of COVID-19 vaccination for the elderly is needed， and the existing vaccination model is overwhelming. We should establish a permanent mechanism based on the family doctor system to transfer from a mobilization model to a regular vaccination model.

To investigate the antiox idant effect of Tiandi Tang to mice testide mitochondrion.METHOD:D-g alactose-induced model senile mice was used,giving Tiandi Tang extracts,measuri ng the activities of GSH-Px，Na+，K+-ATPase and the content of MDA of testid e mitochondrion.RESULTS:Polar extracts of Tiandi Tang had antioxidan t action.CONCLUSION:The effect of Tiandi Tang polar extracts was one of the main mechanisms of antiaging.