"once demonstrated that" is a correct and usable phrase in written English
It is typically used to indicate that something has been proven or shown to be true or effective in the past. Example: The experiment once demonstrated that plants can survive in zero gravity environments.
To shake hands once demonstrated that you did not hold a sword, but to extend your hand today does not imply that you suspect another is armed.
And yes, this can actually affect our most important decisions: UMass professor Ed Saunders once demonstrated that a sunny day in New York can cause investor optimism and therefore lead to a bump in the New York Stock Exchange.
Once demonstrated that nuclear muNS-derived inclusions are able to recruit IC-tagged proteins, we assessed the validity of our system to detect protein-protein interactions within the nucleus.
Once demonstrated that Dil-Ac-LDL+ cells dispersed in the matrigel biopolymer derived from the muscular interstitial space, we performed a similar experiment, injecting only matrigel loaded with VEGF without the previous intramuscular Dil injection.
Nevertheless, once demonstrated that Trp-377 is the main substrate oxidation site in A. auricula-judae DyP, it is difficult to unambiguously identify these second/third catalytic sites due to the variety of exposed aromatic residues in this haem peroxidase.
Once demonstrated that reduction in cholesterol level does not cause cancer this has been assumed as a preclinical effect of malignancy considering that cancer cells up take cholesterol and decreases its levels.
Others players have also been motivated to come back and play more than once, demonstrating that the approach proposed had some success.
Kennedy elected not to speculate on the matter, for once demonstrating that the repetition of campaign talking points can help to paper over a host of media sins.
Mr. Putin has rarely wanted for a dramatic gesture, and the dismissals demonstrated that point once more.
Sprave once demonstrated a slingshot that shoots live chainsaws on his Slingshot Channel.
If Super Tuesday once again demonstrated that Mr. Romney is not likely to win the nomination by acclamation, it also demonstrated (once again) that all of the other candidates have deeper flaws.
