Population inversion induced by collisions in a two level system under nonresonance optical excitation.

When the gas particles, which can be considered as a two level quantum system, are affected by frequent collisions with buffer gas particles (thermal reservoir), the spectral densities of the Einstein coefficients for absorption and induced emission are unequal to each other far from the absorption (emission) line. The relationship between the spectral densities at the specified condition reveals new physical phenomena. The mostly convincing example is the fact that population inversion is established in a two level system under nonresonance optical excitation.

[An algorithm approach to the diagnosis of the forms of bronchial asthma (based on anamnestic data)].

Analysis of complaints and anamnesis in asthmatics suggested by the authors facilitates recognizing forms of the disease at the very first consultation and allows to single out effectively subjects with IgE-dependent asthma. The approach presented in the article makes it possible to prevent complications and work out preliminary plan of examination and treatment. Statistical data on ratio of patients with different forms of asthma confirmed by clinical-laboratory study indicate 3-fold increase in number of patients who have signs of atopy for the last 17 years.