神经外科是医学中的一个亚专业，专门研究神经系统疾病的手术治疗。

Neurosurgery is a ___subspecialty of medicine that focuses on surgical treatment for nervous system disorders.

她在医学领域的心血管疾病研究是一个重要的亚专业。

Her research in cardiovascular diseases is a key ___subspecialty in the medical field.