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A model is developed for tensile fracture under compression for a brittle material with microcracks. The final stage of failure with the formation of macroscopic‐splitting cracks is considered. Pre‐existing microcracks act as a converter of compression into tension in one direction. This results in the nucleation of other tensile microcracks. Rupture of spacings between the microcracks generates a mode I macrocrack parallel to the direction of maximum compression. Crack propagation is due to sliding along planes that are inclined to the compression microcrack surfaces and is stimulated by the forces distributed along the interacting macrocrack surfaces. Equilibrium, stability and growth of cracks are studied on the basis of the theory of fracture mechanics under the assumption of the plane strain state. The behaviour of both short and long macrocracks are analysed. Parameters of the model are evaluated with the help of data from fracture experiments on some rocks.

The paper presents the results of study of the clinical and functional characteristics of chronic obstructive pulmonary disease III degree. The peculiarities of hormonal status by determining the hormones as cortisol, aldosterone, DHEA-S are revealed. At the correlation determining of hormone levels with clinical signs it was established significantly lower levels of cortisol, aldosterone, and DHEA-S at severe and very severe dyspnea in patients with COPD III degree. The use of low-intensity laser radiation in the treatment of patients with chronic obstructive pulmonary disease improves clinical features and laboratory data on improved hormonal status, including significant increase in cortisol, aldosterone, DHEA-S, and reduces the duration of acute illness and financial expenses in the inpatient treatment of patients, improves the quality of life in patients with chronic obstructive pulmonary disease. Correlation analysis showed the presence of multiple linear relationships between hormone levels and clinical signs. Correlation between levels of cortisol, aldosterone, and DEHA-S with the main clinical laboratory and functional indicators of COPD was defined. It was found that reducing the concentration of hormones is accompanied by varying degrees of severity of the deterioration of clinical, laboratory and functional parameters that determine the severity of the disease. The proposed method of hormone therapy is effective, safe, well tolerated and doesn’t cause side effects. The data on the effectiveness of complex treatment can be used in treatment, clinical examination of the design of programs, prevention and rehabilitation of patients with COPD.

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