RESUMEN
PURPOSE: To determine whether extremely low frequency electromagnetic fields can alter average free cytosolic calcium ion concentrations [Ca2+]i and transient increases in [Ca2+]i in populations of ROS 17/2.8 cells. MATERIALS AND METHODS: Cells loaded with the calcium-selective luminescent photoprotein, aequorin, were placed in the bottom of a sample chamber, which was inserted into the gap of a previously described air gap reactor system where they were exposed either to sinusoidal magnetic fields at a variety of frequencies and flux densities or to sham conditions. Real-time recordings of photon counts due to aequorin luminescence were obtained and data were analysed with the use of probit plots. RESULTS: Probit plots of data obtained from cells exposed to the various magnetic fields were virtually superimposable over the data obtained for the same cultures during pre- and post-exposure sham or no-field periods. CONCLUSION: These experiments provided no evidence for any effects of ELF EMF, either positive or negative, on either average [Ca2+]i or on transient increases in [Ca2+]i.
Asunto(s)
Calcio/metabolismo , Aequorina/farmacología , Animales , Relación Dosis-Respuesta en la Radiación , Campos Electromagnéticos , Iones , Mediciones Luminiscentes , Neoplasias/radioterapia , Fotones , Ratas , Factores de Tiempo , Células Tumorales CultivadasRESUMEN
Ribbonlike magnetoelastic sensors can be considered the magnetic analog of an acoustic bell; in response to an externally applied magnetic field impulse the sensors emit magnetic flux with a characteristic resonant frequency. The magnetic flux can be detected external to the test area using a pick-up coil, enabling query remote monitoring of the sensor. The characteristic resonant frequency of a magnetoelastic sensor changes in response to mass loads. [L.D. Landau and E. M. Lifshitz, Theory of Elasticity, 3rd ed. (Pergamon, New York, 1986). p. 100].Therefore, remote query chemical sensors can be fabricated by combining the magnetoelastic sensors with a mass changing, chemically responsive layer. In this work magnetoelastic sensors are coated with humidity-sensitive thin films of ceramic, nanodimensionally porous TiO2 to make remote query humidity sensors.