The phrase "more persistent in" is correct and usable in written English.
It is often used to indicate that someone is more committed to achieving a certain goal or reaching a certain outcome than before. For example: Despite facing several obstacles, she remained more persistent in her efforts to complete the project.
"I think we must be more persistent in rooting out these activities".
Amazingly, the pressure on Rushdie may be even more persistent in his homeland than in the Iranian theocracy.
Despite the previous reports, The Times should have been more persistent in seeking comment from the military.
That is likely to make the Germans more persistent in their push to create a pan-European exchange.
They became more open to new perspectives, more intimate in their relationships and more persistent in overcoming challenges.
But now I began to wonder what would have happened if we had been a little more persistent in our efforts.
Data available in the regulators' own assessment report shows it could be 10 times more persistent in soils than the European safety limit".
MR imaging showed that ZWC-coated NPs were more persistent in tumors than PEG-coated NPs, in agreement with the in vitro results.
With pre-session feeding, responding did not change systematically across test sessions and tended to be more persistent in the richer component.
"We're merely hearing the president more lately and that's because Khamenei has become more persistent in expressing his views, views which often are in contrast with those held by the government".
In contrast, imaging contrast agents (used predominantly for diagnosis), which include metals such as iron, are likely to be more persistent in the body, requiring greater consideration of their impacts on inflammation as well as their long-term effects on patients.
