The phrase "are used simultaneously" is correct and usable in written English.
It can be used when describing two or more things that occur at the same time.
Example: "In this experiment, the two methods are used simultaneously to achieve more accurate results."
Alternatives: "are utilized at the same time" or "are employed concurrently".
"This could be useful in developing new combination therapies, where multiple drugs are used simultaneously to treat a cancer by attacking different parts of the cancer cells at the same time".
This resistance to interference by other TetR-based transregulators makes the new sc-rtTA variants very useful in applications where multiple TetR-based regulatory systems are used simultaneously.
In many an organization, both approaches are used simultaneously.
Experiments on monkeys suggest this might work, particularly if two drugs are used simultaneously.
Both are used simultaneously to describe the color images including more edges than usually used.
In some instances, nuclear medicine technologies and other techniques are used simultaneously, such as when computed tomography is combined with PET or single photon emission computed tomography (SPECT).
It is shown that the optimization process is more effective when both mechanical and electromagnetic parameters are used simultaneously.
Several approaches for generating improved multiperiod azeotropic design solutions are developed and are used simultaneously in a large-scale demonstration.
For the first time, two types of dynamic performance constraints are used simultaneously within the adopted framework.
Feedback and feedforward control strategies are used simultaneously in order to achieve maximum net power and prevent oxygen starvation.
The frequency with which they occur depends, in part, on the number of different drugs that are used simultaneously.
