The phrase "a very important effect" is correct and usable in written English.
You can use it when discussing the significance or impact of something in a particular context, emphasizing its importance.
Example: "The new policy has a very important effect on employee morale and productivity."
Alternatives: "a crucial impact" or "a significant influence."
The interface roughness (amplitude) also has a very important effect on the effective thermal conductivity of the as-sprayed TBCs.
"This case will have a very important effect on how company stock will be used in the future".
Now, if in fact that condition is violated, then we end up with a very important effect.
Facility layout design (FLD) has a very important effect on the performance of a manufacturing system.
It is well known that surface roughness has a very important effect on superhydrophobicity.
It could be found that the type and position of fluorine-containing group as X or Y on benzene ring had a very important effect on herbicidal activity.
These experimental results have also demonstrated the very important effect of tube spacers on the hydrodynamics.
The distinct difference of the OFETs performance suggests that the intermolecular non-covalent interactions have very important effect on gearing the molecular packing and properties.
For example, Lin and Duan [8] considering the nonthermal ion in a dusty plasma derived a Korteweg de Vries (KdV) equation for DA wave and it was found that the nonthermal ions have very important effect on the propagation of DA solitary waves.
Zheng and coauthor had found that distinct sequence and structural features between alternative splicing and constitutive splicing, including exon length and repetitive elements, have very important effect on the splicing of ASEs [26].
Importantly, we also argued that "Step 1, the appearance of RNA editing activity, has the very important effect of making these transitions neutral".
