The phrase "a useful agent" is correct and usable in written English.
It can be used to describe someone or something that serves a beneficial purpose or function in a particular context.
Example: "In the context of environmental conservation, a useful agent can be a species that helps maintain the ecosystem's balance."
Alternatives: "a helpful factor" or "a beneficial element."
Then we examined whether erlotinib could be a useful agent for bone metastases of NSCLC using our novel osteolytic bone invasion model.
The results may lead to designing RNA targeted therapeutics and a useful agent in gene regulation in eukaryotic cells.
In conclusion, we suggest that 1-methylnicotinamide might be a useful agent for treating brain failures related to diabetes.
Dexmedetomidine is a highly selective alpha-2 adrenergic agonist which is a useful agent because it provides anxiolytic and sympatholytic effects, analgesia, and conscious sedation without respiratory depression.
Ginsenoside Rg1, which could improve spatial learning and memory, might be a useful agent for preventing and treating cognitive impairment in Alzheimer's disease (AD).
The successful conjugation of biotin to magnetic nanoparticles and their super paramagnetic behaviour, evident from FTIR and VSM, suggest that the synthesized biotinylated magnetic nanoparticles could be a useful agent in contrast-enhanced MRI.
In summary, our data demonstrate that chrysin is a potentially useful agent for the treatment of EAN with its anti-inflammatory and neuroprotective effects.
Therefore, Ankascin 568 plus may be a potentially useful agent for the regulation of blood lipids and the treatment of coronary artery diseases.
Overall, these data suggest that lapatinib may be a clinically useful agent for the treatment of lung cancer.
However, because gelonin is 5-10 times less toxic than saporin, the therapeutic ratio for gelonin is superior, making it potentially a more useful agent for human treatment.
Ivabradine is a particularly useful agent in this context because it acts on the If channels in the sinoatrial node and lowers the heart rate without substantially affecting cardiac contractility.
