RESUMEN
The clinical material obtained surgically in patients with kidney stone disease (KSD) was tested for content of the stone microflora using PCR and standard microbiological methods. It was demonstrated that about 50% of stones in patients with KSD were infected with various infection agents as observed using standard microbiological and molecular genetic methods. The percentage of detection of the Mycoplasma hominis using cultural method is lower than the percentage detected using PCR, which is due to difficult isolation and cultivation, as well as DNA fragments of mycoplasma observed after antibiotic therapy. Studies based on modern microscopy methods showed that microorganisms on the surface of the kidney stone formed multispecies biofilms.
Asunto(s)
Cálculos Renales/microbiología , Antibacterianos/uso terapéutico , Técnicas Bacteriológicas , Biopelículas/efectos de los fármacos , Humanos , Cálculos Renales/cirugía , Consorcios Microbianos/fisiología , Microscopía Electrónica , Mycoplasma hominis/genética , Mycoplasma hominis/aislamiento & purificación , Mycoplasma hominis/fisiología , Reacción en Cadena de la Polimerasa , Ureaplasma/genética , Ureaplasma/aislamiento & purificación , Ureaplasma/fisiologíaRESUMEN
We investigate the effects of a linear resonator on the high-frequency dynamics of electrons in devices exhibiting negative differential conductance. We show that the resonator strongly affects both the dc and ac transport characteristics of the device, inducing quasiperiodic and high-frequency chaotic current oscillations. The theoretical findings are confirmed by experimental measurements of a GaAs/AlAs miniband semiconductor superlattice coupled to a linear microstrip resonator. Our results are applicable to other active solid state devices and provide a generic approach for developing modern chaos-based high-frequency technologies including broadband chaotic wireless communication and superfast random-number generation.
RESUMEN
We study 2D and 3D localized oscillating patterns in a simple model system exhibiting nonlinear Faraday resonance. The corresponding amplitude equation is shown to have exact soliton solutions which are found to be always unstable in 3D. On the contrary, the 2D solitons are shown to be stable in a certain parameter range; hence the damping and parametric driving are capable of suppressing the nonlinear blowup and dispersive decay of solitons in two dimensions. The negative feedback loop occurs via the enslaving of the soliton's phase, coupled to the driver, to its amplitude and width.
RESUMEN
The prevalence of smoking is very high and growing in Siberia. Three population surveys carried out by the Institute of Internal medicine within the framework of the MONICA project (WHO) during 1988-1995 revealed that 59% of the men and 11% of the women aged 25-64 are smokers (2). The number of smokers among children is also growing: 21% of girls and 40% of boys aged 14-17 are smokers (1). Tobacco product advertising is widespread in the city. Cheap cigarettes of bad quality are easily available for the population. The economic situation in the region makes it difficult for people to pay for specialised treatment. That is why new methods of smoking prevention should be found. The main components of our work are: involving local decision-makers in the activity, educating the population, work with mass media, epidemiological studies, international Quit & Win campaigns.