Funding for this research was provided by:
National Natural Science Foundation of China (8187052509)
National Clinical Research Center for Geriatric Diseases (NCRCG-PLAGH-2018006)
Article History
Received: 31 October 2019
Accepted: 7 January 2020
First Online: 10 January 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All studies in this review have been approved by the local ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.