RESUMO
Inactivation of VEE virus with laser UV impulses of nano- and picosecond duration was investigated. It has been shown that in both cases there is a decrease of the inactivation cross-section with the rise of irradiation intensity. It points to the fact that the major lethal photoproduct in VEE is formed by a single-quantum mechanism.
Assuntos
Alphavirus/efeitos da radiação , Lasers , Raios UltravioletaRESUMO
A study was made of the lethal effect of pulse laser (second harmonic Nd+3:YAG laser of 532 nm, pulse length 3.3.10(-11) s, peak intensity from 4.10(12) to 1.10(14) W/m2) on HeLa cells at the phases of active and stationary growth, and lethal and mutagenic effects of this radiation on E. coli cells. As was shown, HeLa cells at both growth phases and E. coli cells exhibited low sensitivity to laser radiation at lambda = 532 nm.
Assuntos
Lasers/efeitos adversos , Mutação , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Escherichia coli/efeitos da radiação , Células HeLa , Humanos , Fatores de TempoRESUMO
Formation of cross-links and local denaturated sites in double-stranded DNA of bacteriophage CD under picosecond laser UV irradiation was investigated by fluorescent method. It is shown that passing from low-intensity UV irradiation with mercury lamp to high-intensity laser UV irradiation quantum, yield of cross-links formation increases by an order.
Assuntos
DNA Viral/efeitos da radiação , Lasers , Desnaturação de Ácido Nucleico/efeitos da radiação , Raios Ultravioleta , Bacteriófagos/metabolismo , Bacteriófagos/efeitos da radiação , DNA de Cadeia Simples/metabolismo , DNA de Cadeia Simples/efeitos da radiação , DNA Viral/metabolismo , Técnicas In Vitro , Espectrometria de FluorescênciaRESUMO
Two-step photochemical decomposition of aromatic amino acids under picosecond laser UV-irradiation was investigated. These results were compared with the photochemical stability of nucleic acid bases. Using the known ratio between the nucleic acid bases and aromatic amino acids in native bacteriophages lambda and phi X174 it was shown that picosecond laser UV-inactivation of viruses occurred due to the photodegradation of nucleic acid.
