"twofold effect" is a grammatically correct phrase in written English.
It is typically used to describe something that has two separate outcomes or results. Here is an example: "The new policy had a twofold effect on the company: it increased profits, but it also led to a decrease in employee morale."
This has had a twofold effect.
For a parent, watching these monsters has a twofold effect.
Elevated atmospheric concentrations of carbon dioxide have a twofold effect on the world's oceans.
Güllner said Petry's comments about being able to shoot refugees on the border had had a twofold effect.
That fabled period, the way he talked about it, had a twofold effect on his family and friends: it laid them low financially while drawing them closer personally.
With each contraction a twofold effect is produced to facilitate the dilation, or opening, of the cervix.
Tweaks aside, the twofold effects of the School Lunch Act are much the same now as 60 years ago.
For example, the twofold effects of emotion on attention have been almost exclusively reported in paradigms using either arousing, and mostly negatively valenced words or fearful facial expressions.
The twofold effects of DBTC on the pancreas are mediated by a biliary obstructive component and secondly a direct toxic effect.
In the realization of n-type OFET, the LUMO level lowering provides a twofold beneficial effect: firstly, an effective charge-injection can be achieved using gold or other high work function metals, and secondly, the electron transport is made less sensitive to charge trapping mechanisms related to the interaction with ambient agents such as oxygen and humidity [4].
In a colon xenograft model, it showed an almost twofold greater effect in inhibition of tumor cell growth compared to Vorinostat (Novoty-Diermayr et al. 2010).
