Funding for this research was provided by:
National Natural Science Foundation of China (no.80471051, 81270379, 81070231, and 91649110)
Text and Data Mining valid from 2018-07-20
Received: 21 March 2018
Accepted: 11 July 2018
First Online: 20 July 2018
Ethics approval and consent to participate
: Blood was collected from healthy donors who provided written informed consent. The experiments were conducted according to the principles of the Declaration of Helsinki. This study was approved by the Ethics Committee of the Beijing Institute of Geriatrics (no. 2015026).
: Not applicable.
: The authors declare that they have no competing interests.
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