RESUMO
Acoustic radiation forces have often been used for the manipulation of large amounts of micrometer sized suspended particles. The nature of acoustic standing wave fields is such that they are present throughout the whole fluidic volume; this means they are well suited to such operations, with all suspended particles reacting at the same time upon exposure. Here, this simultaneous positioning capability is exploited to pre-align particles along the centerline of channels, so that they can successively be removed by means of an external tool for further analysis. This permits a certain degree of automation in single particle manipulation processes to be achieved as initial identification of particles' location is no longer necessary, rather predetermined. Two research fields in which applications are found have been identified. First, the manipulation of copolymer beads and cells using a microgripper is presented. Then, sample preparation for crystallographic analysis by positioning crystals into a loop using acoustic manipulation and a laminar flow will be presented.
RESUMO
Sensory conduction velocities of normal subjects are increasing linearly with rising temperature. The duration of the compound sensory action potentials recorded from the median nerve at the wrist and elbow shows a negative temperature coefficient. The peak-to-peak amplitude of these potentials increases from 22 degrees to approximately 26 degrees C and then decreases progressively again up to 36 degrees C. It is believed that this behavior is due to a combination of decreasing temporal dispersion, height and duration of the individual spike potentials.
