PURPOSE To evaluate the effect of power, vacuum, and flow rate on endothelial cell loss after phacoemulsification. SETTING Labbafinejad Medical Center Medical Center, Tehran, Iran. METHODS In a prospective randomized clinical trial, phacoemulsification was performed in 2 groups (high vacuum and low vacuum) with 3+ nuclear sclerosis. The stop-and-chop technique was used with the Sovereign ma...

The general thermodynamic analysis of the quantum vacuum, which is based on our knowledge of the vacua in condensed-matter systems, is consistent with the Einstein earlier view on the cosmological constant. In the equilibrium Universes the value of the cosmological constant is regulated by matter. In the empty Universe, the vacuum energy is exactly zero, λ = 0. The huge contribution of the zero...