Active galactic nuclei (AGNs) are believed to emit radiations using the gravitational
energy released through accretion onto black holes. For low accretion rates, the flows
are so hot and tenuous that non-thermal protons naturally exist inside the flows. In the
first part of this talk, I discuss the effects of non-thermal particles on the dynamical
structure of hot accretion flows using one-dimensional equations including the feedback
from non-thermal particles consistently. It is found that for the flow structure to
change to a Keplerian disk, the escaping protons need to extract almost all the energy
released. Since this situation is quite extreme, it seems difficult that the non-thermal
particles affect the dynamical structure of the hot accretion flows. In the second part
of this talk, I discuss the emission of neutrinos from Low-Luminosity AGNs (LLAGNs)
using the Fokker-Planck equation. For a typical LLAGN, the diffusive escape suppresses
the acceleration of protons. The diffuse neutrino intensity from LLAGNs is calculated,
and it is found that the observed IceCube data can be fitted for reasonable
parameters. Although LLAGNs are much fainter than quasars, they can contribute to the
diffuse neutrino intensity owing to their high number density.