The phrase "a significant modification of" is correct and usable in written English.
It can be used when discussing changes or alterations that have a considerable impact on something.
Example: "The new software update includes a significant modification of the user interface, enhancing overall usability."
Alternatives: "a major change to" or "a substantial alteration of".
That would be a significant modification of a contractual right.
A significant modification of the electronic structure has been revealed at flake edges and grain boundaries.
A significant modification of the cobalt surface was observed with time on stream.
A significant modification of the pPb spectra with respect to the pp spectra is observed in all p(T ave) intervals investigated.
4 Even courts from other jurisdictions which have adopted this theory have recognized that it is a significant modification of or deviation from the traditional theories of causation.
It is demonstrated that the variation of the substrate temperature results in a significant modification of the film morphology.
This is a slow decay, which leads to a still significant modification of the wave energy absorption at long distance (up to 15% at a distance of 2000 m).
Although global gene expression can result quantitatively altered by the tumorous condition, a significant modification in the pattern of reciprocal expression between overlapping genes is unlikely.
We did not find a statistically significant modification of effect, but we found that acute or chronic lower respiratory disease had important effects on response to PM10.
1– 3 Deposition of molecules on conducting electrodes may significantly affect their intrinsic chemical, optic and magnetic properties that can result in a correspondently significant modification of the structural and electronic characteristics of the molecule.
They found a statistically significant modification of temperature on the association between exposure to sulphur dioxide and total excess mortality, although the main effect of this pollutant was not statistically significant.
