Thermodynamic properties and lattice dynamics investigation of LuBC: experiment and ab initio calculations.

A sample of lutetium carboboride LuB2C was synthesized from a mixture of lutetium hydride, boron and carbon by annealing in argon. The temperature dependence of the heat capacity Cp(T) (2-300 K) and lattice parameters a(T), b(T), and c(T) (5-300 K) of the carboboride was experimentally determined. The experimental values of the heat capacity were fitted with the approximation Cp(T) = aT + ΣCD + CE + CTLS(T).

Dynamics of the crystal structure of tin-based type-I clathrates with different degrees of disorder in their cationic frameworks.

The temperature dependencies of heat capacity, C(T), and cubic unit cell parameter, a(T), were experimentally obtained in the range of 2-300 K for the compounds SnPI, SnZnPI, and SnZnPI, which belong to a family of type-I clathrates. The experimental data were analyzed in the frames of the Debye-Einstein approximation, further accounting for the contributions of positional disorder in the clathrate frameworks as well as those of defect modes arising from the distribution of guest atoms over unequal in energy but close in space positions inside the framework cages. By fitting the experimental data, the Debye and Einstein characteristic temperatures describing the dynamics of the framework and guest atoms, respectively, were obtained.

Structural irregularities and peculiarities of low-temperature thermal properties of SnPBr clathrate.

Temperature changes of the heat capacity and unit cell parameters of SnPBr clathrate were experimentally determined in the temperature range of 2 to 300 K. The data obtained were analyzed using Debye-Einstein approximation and taking into account the impact of both disorder in the host matrix and the presence of vacancies in the framework. Anomalous negative contribution to the thermal expansion was revealed and related to the defect mode influence on the clathrate thermal properties as a result of vibrations of two-level systems (TLS).

[Vasaprostan treatment of fibrosing alveolitis in patients with pulmonary hypertension].

Aim: To study clinical efficacy of vasaprostan in patients with fibrosing alveolitis (FA) complicated by pulmonary hypertension (PH), its effect on functional activity of platelets and endothelium, intensity of free radical processes.

Material And Methods: Seven FA patients were examined. They had either idiopathic FA or FA with diffuse diseases of the connective tissues.