RESUMO
The influence of magnetic field of strength 18 Gauss and power frequency 50Hz on the dielectric properties of hemoglobin molecule in the frequency range from 20Hz to 100kHz, measured using RLC bridge is studied. The Cole-Cole model gives a good fit for the experimental dielectric data for the control and the exposed hemoglobin samples to the magnetic field. The obtained fitted parameters have been presented for the control and the exposed hemoglobin samples to the magnetic field with different exposure times. The induced polarization is due to the counter-ions around the hemoglobin molecules. The results show that exposure to the magnetic field causes a decrease in the dielectric increment [epsilon] and relaxation time [t], and increase in static conductivity [sigma] and little change in the alpha-parameter of the hemoglobin molecules. As the exposure time to the magnetic field increases more decrease in the dielectric increment and relaxation time and more increase in static conductivity occur
Assuntos
Masculino , Animais de Laboratório , Índices de Eritrócitos , Camundongos , Condutividade ElétricaRESUMO
Tumor angiogenesis is an important step for tumor growth and metastasis. There are specific growth factors operating in this process such as VEGF. The aim of this study is to examine the effect of single exponential electric field pulse of different intensities from 0.3 kv/cm to 1.65 kv/cm and 1 ms duration on the VEGF level in the cultured human C.N.S tumor cells. VEGF level is determined by Enzyme Immunoassay [EIA] technique in cell culture and its supernatant. The results showed that high intensity electric field pulse decrease VEGF level in the cells. Also, it was found that the rate of growth of tumor cells decreased with field intensity elevation as indicated by morphological observations