Mayor of Yerevan Hayk Marutyan on Thursday signed a decision on conferring titles of chief specialist of Yerevan upon several doctors, including allergologist Kristina Jamalyan, neurologist Lidia Gimoyan, dentist Izabella Vardanyan, virologist Arshak Ghazaryan, doctor-laboratory assistant Vahagn Gevorgyan, vascular surgeon Tigran Kamalyan and pulmonologist Ashot Yeghoyan.