[Damage of the knee posterior cruciate ligament: biomechanics, basic diagnostics, treatment and secondary osteoarthritis prevention directions]

The analysis of literature data was performed on the pathogenesis, diagnosis and treatment of injuries of the posterior cruciate ligament (PCL) of the knee joint. PCL is the largest intra-articular ligament of the knee joint, can withstand the maximum loads compared with other ligaments. It was noted that, in general, in cases of damage to the PCL, it is necessary to use a set of diagnostic methods, and the basic principles for the choice of optimal treatment plan for this patient. It considered the results of the conservative treatment of PCL partial ruptures, and it is indicated that this approach increases the risk of degenerative anatomical structures and functional disorders of the joint. It was noted that it is advisable to conduct surgical treatment to restore the stability of the knee joint and normalize function, while a number of methods for the reconstruction of PCL have been proposed to date. The usage of chondroprotectors for prevention of the secondary osteoarthrosis of the knee joint affected by posterior cruciate ligament rupture was analyzed in the literature data.

Effects of pressure and composition on Raman spectra of CO-H2-CO2-CH4 mixtures

There is great interest in the development of renewable and environmentally friendly fuel sources such as biogas and syngas for generation of heat and electricity. Raman spectroscopy is a promising method for rapid quantitative analysis of the composition of such gases. To improve the accuracy of the method, information is needed on changes in the spectra of the main components as a function of pressure and gas composition. In this work the spectral characteristics of the most intense peaks of methane, carbon monoxide, carbon dioxide and hydrogen in the range of 200-3800 cm^-1 were investigated in the range of 1-25 bar for pure gases and binary mixtures. It has been revealed that, under these conditions, the change in the characteristics of pure rotational hydrogen lines is negligible, while the Q-branches of the main vibrational bands of methane, carbon monoxide and carbon dioxide shift to a few tenths of cm^-1. The values of errors that can occur in the case of ignoring such changes in the spectra are estimated.