ABSTRACT
The ternary half-Heusler compounds have shown great potential for realizing new 3D topological insulators. With band gap tuning and spin orbit coupling these compounds may undergo topological phase transitions. In present work, we explore the possibility of realizing a topological insulating phase in half-Heusler family NaYO (Y= Ag, Au, and Cu). We find that for NaAgO, external strain (â¼19%) along with spin-orbit coupling (SOC), is required to achieve band-inversion at Γ high-symmetry point and leads to phase transition from trivial to non-trivial topological insulating phase. In case of NaAuO and NaCuO, non-trivial phase appears in their equilibrium lattice constant, hence only SOC is enough to achieve band-inversion leading to non-trivial topology. The non-centrosymmetric nature of crystal geometry leads to the formation of two twofold degenerate point nodes near the Fermi level.
ABSTRACT
Hydatid disease is a zoonotic infestation caused by larval cestode of genus Echinococcus. Cystic form of this infection mostly involves liver and lung. Hydatid disease of the parotid gland is very rare even in endemic areas and is often clinically mistaken for parotid tumors or cysts. The presence of protoscolices, laminated membranes, and isolated hooklets are characteristic cytological features observed on fine-needle aspirate from hydatid cysts. We report unusual cytological features from a hydatid cyst of parotid in a 13-year-old girl. She presented with a slowly enlarging hard mass in left parotid. Fine-needle aspiration yielded slightly turbid fluid. Smears from the sediment revealed naked parasitic micronuclei, fragments of germinative layer (endocyst), and abortive brood capsules (buds from endocyst) seen as spherical structures with multiple parasitic nuclei. Some of these spherical structures were degenerated with recognizable nuclei and others were completely necrotic. Diagn. Cytopathol. 2016;44:770-773. © 2016 Wiley Periodicals, Inc.
