The phrase "a slow but persistent" is correct and usable in written English.
It can be used to describe something that progresses gradually over time but continues to make progress without giving up.
Example: "The project faced many challenges, but it was a slow but persistent effort that ultimately led to success."
Alternatives: "gradual yet steady" or "slow yet unwavering".
We also observed a slower, but persistent loss of GFP-AR nuclear intensity in both the untreated, treated, and ligand withdrawn HeLa GFP (Supplementary Fig. S3B C).
Thus BX displays a faster but adaptive response, while AX displays a slower but persistent response.
Subsequently, viral load declines with a slower but persistent rate approximately equal to δ × ε.
Simulations suggest the evolutionary rate signatures are a combination of surface transport mechanisms, which are occurring with irregular periodicity but over longer distances across YNP, and on a relatively slow but persistent hydrothermal "conveyer" that would drive dispersal of chemotrophic communities through a YNP subsurface biosphere.
In addition, while telomerase deficiency causes a relatively slow, but persistent, accumulation of DNA damage, ATR elimination leads to an immediate catastrophic loss of genome integrity and clearance of the damaged cells (Ruzankina et al, 2007).
A slow developing but persistent rundown in total transient current follows this temporary reduction.
Indeed, most studies in patients have dealt only with the effects of the mediators of inflammation on acute phenomenon [2], [6] and few investigations have centered on the side effects of inflammatory mediators when the onset is slow but persistent over a prolonged period [7], [8], [11].
It is also evident that slow but persistent changes in serum creatinine over a longer time course than 48 hours can be missed and sometimes impossible to classify.
In my slow but persistent bid for the reader's sanity, I hereby prescribe a period of allowing things to be adequate.
