The fact known from ab initio calculations, that in molecular systems with real Hamiltonian, surrounding a two-state conical intersection (ci) with a small circle in the configuration space of nuclear coordinates the angle of the adiabatic-to-diabatic transformation (ADT) matrix forms a phase of Air Max 90 Em ±π, is rigorously proved for the most general case and a condition is given to decide whether +π or −π values should be assigned to the particular seam of ci. We show how can be explained on a straightforward way the disappearance i.e. the `pair annihilation' of conical intersections with the aid of ±sign attached to the ci.
Teratomas and other germ cell tumors are common pediatric neoplasms. They may have gonadal and extragonadal locations. Congenital teratomas of the neck are unusual.Imaging provides early diagnosis, which is crucial for planning the delivery, definitive treatment and that of associated complications. This report describes the prenatal sonographic features of fetal neck teratoma and its role in early diagnosis and treatment.A 30-year-old gravid woman presented with polyhydramnios in 31 weeks. Ultrasound scan revealed fetal complex neck mass of heterogenous texture and marked Air Max polyhydramnios. The mass was excited in the early neonatal period and teratoma was confirmed on histology.