Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Different uppercase letters on the error bar indicated extremely significant differences (P < 0.01), different lowercase letters indicated significant differences (P < 0.05), while the same letters show no significant differences (P > 0.05).
