In this paper, various designs of non-resonant photoacoustic cells with a different arrangement of microphones are investigated. It is demonstrated that it is possible to expand the dynamic range of measurement of gas concentration using the special configuration of cell cavities and the specific location of the microphone. The suppression of resonant acoustic effects occurring in the measuring photoacoustic cell is characteristic of this cell cavity design. Given this suppression, only the primary sound wave affects the microphone diaphragm. The implementation of a new cell design allows us to extend the range of measurement of SF6 gas impurity concentration in the atmosphere from 100 - 1000 ppm up to 10 - 10,000 ppm.
The of multiphoton microscopy (MPM) based on two-photon fluorescence and second-harmonic generation is promising for diagnosing neoplastic transformation of tissues. The results of MPM studies of tissues with prostate adenocarcinoma embedded in paraffin blocks are presented. The tissue fluorescence was also analyzed using the fluorescence lifetime (Fluorescence-lifetime imaging microscopy - FLIM) option. The relationships between the fluorescence peculiarities and the second harmonic generation of the prostate gland tissues were obtained for different morphological images.
Low-level laser exposure is a non-invasive and less painful method, which is used as an alternative method to classical acupuncture with metal needles and could be applied in clinical medical practice. The study of the laser acupuncture effect on the electroencephalogram (EEG) characteristics was carried out. The electrodes were located on the surface of the subject's head according to the standard scheme 10-20. Experimental EEG data were obtained by standard digital 16-channel electroencephalograph with EEG18 V5.0.3 software. The EEG frequencies in each of the measurements have been analyzed. This work shows that low-level laser stimulation able to change the power of rhythms in the head areas, which corresponds to the stimulation of different brain regions.