In vivo monitoring of vascularization and oxygenation of tumor xenografts using optoacoustic microscopy and diffuse optical spectroscopy.

The research is devoted to comparison of the blood vessel structure and the oxygen state of three xenografts: SN-12C, HCT-116 and Colo320. Differences in the vessel formation and the level of oxygenation are revealed by optoacoustic (OA) microscopy and diffuse optical spectroscopy (DOS) respectively. The Colo320 tumor is characterized by the highest values of vessel size and fraction. DOS showed increased content of deoxyhemoglobin that led to reduction of saturation level for Colo320 as compared to other tumors. Immunohistochemical (IHC) analysis for CD31 demonstrates the higher number of vessels in Colo320. The IHC for hypoxia was consistent with DOS results and revealed higher values of the relative hypoxic fraction in Colo320.

[Quantitative estimation of the perception of the frequency of tonal sounds by human].

The possibility of a purely instrumental investigation of the sensory characteristics of human in the real time scale has been shown using an analyzer of tonal hearing as an example. In accordance with the previously developed approach, the mean-square errors of the deviation of the instantaneous frequency of tonal sounds from its average value upon their vocal reproduction by persons being tested as well as upon their reproduction by a special electronic sound generator requiring a continuous comprehended regulation for maintaining the wanted frequency were chosen as these characteristics. It was found that the mean-square deviation of the current reproducible frequency linearly depends on the average frequency of the reproducible tonal sound. The method can be used without radical changes for studying the characteristics of human sensory analyzers with the use of stimuli of other modalities to control the state of the sensory sphere of the human operator, to solve the problems of the synthesis of human--machine interfaces, and to construct "virtual reality" systems.

[Low frequency mechanical properties of human hand soft tissue]. / O nizkochastotnykh mekhanicheskikh svoistvakh miagkoi ruki cheloveka.

Mechanical properties of the hand tissue in various states are studied in the 10 divided by 100 Hz frequency range. The velocity and damping decrement of the acoustic wave are measured. Viscoelastic parameters of the tissue are estimated.