Selective effect of laser radiation on cancer cells and laser spectroscopy of the cell (review)

Abstract

A comparison of the frequencies of stabilized He-Ne/I2'I2 lasers at X = 633 nm in Helsinlu (Finland) is reported. This comparison involved two lasers from the D. I. Mendeleyev Institute for Metrology (Russian Federation) and the Technical Inspection Centre (Finland). The frequency difference between laser radiations is 2,8 kHz with a standard uncertainty of 3,4 kHz.The comparison described here is part of the work carried out between national standards laboratories for the investigation of the metrological characteristics of He-Ne lasers stabilized by saturated absorption on the transition 11-5 R (127) in iodine-127 (He-Ne/lZ7I2). This transition at 633 nm is one of those recommended by the CIPM in 1983 [l] for the practical realization of the metre.Laser comparisons have been carried out within the framework of the D. I. Mendeleyev Institute for Metrology (VNIIM) and the Technical Inspection Centre (TTK) in a joint programme on stabilized lasers. The first comparison of VNIIM and TTK He-Ne& lasers at 633 nm was carried out in December 1987. At that time the frequency difference between the VNIIM laser and the TTK laser TTK2 was (-6+6) kHz. No major modifications have been made to the TTK lasers since that time. The frequency difference between two TTK lasers, TTKl and TTK2, has been in the range ( l o + 10) kHz for many years.The comparison of He-NeA2 lasers reported here was carried out from 8 to 16 January 1991 at Helsinki University of Technology.The TTK laser TTKl used in the comparison has the following characteristics:(a) The length of the cavity made of Invar is 41 cm.

Photodynamic action on some pathogenic microorganisms of oral cavity

“…Theoretical model of photodynamic cell destruction, discussed by Kamalov et al*, show that in case when dominant oxygen amount goes on substrate oxidizing, survived cells number is proportional to normalized dose, in tern dependent from dye concentration and radiation dose 6 : There are two types of reactions where dye being in excited state can react with biological substratum.…”

Inactivation of bacterial cells by dynamic low-coherent speckles: mathematical model of photoprocessing

“…[1,5] the average time of fluctuations of speckles (at their local influence on each cell) is comparable with the characteristic time-passing of photochemical reactions. However, by now, the spatial-temporal characteristics of optical speckles, length and time of coherence of light used for perfusion practically are not considered [6] in the content of primary molecular mechanisms of action of lasers on biological structures.…”