Broad spectral tuning of ultra-low-loss polaritons in a van der Waals crystal by intercalation.

Phonon polaritons-light coupled to lattice vibrations-in polar van der Waals crystals are promising candidates for controlling the flow of energy on the nanoscale due to their strong field confinement, anisotropic propagation and ultra-long lifetime in the picosecond range. However, the lack of tunability of their narrow and material-specific spectral range-the Reststrahlen band-severely limits their technological implementation. Here, we demonstrate that intercalation of Na atoms in the van der Waals semiconductor α-VO enables a broad spectral shift of Reststrahlen bands, and that the phonon polaritons excited show ultra-low losses (lifetime of 4 ± 1 ps), similar to phonon polaritons in a non-intercalated crystal (lifetime of 6 ± 1 ps).

[Physiological adaptation reactions in patients with ischemic heart disease].

The condition was studied of bodily general adaptive reactions in patients with different forms of ischemic heart disease (IHD). Unlike healthy subjects, IHD patients displayed predominance of pathogenetic and dysadaptive type reactions. 88 percent of healthy subjects had reactions of sanogenetic character, with 31.