In this paper we present two filters called Reflection Delayed noise Suppression RDS and Integration Reflection Delayed noise Suppression IRDS whichare useful to increase the dynamics of video CCD cameras. The RDS is a band-passfilter built with a parallel short-circuited line. It lowers significantly the mostimportant noise which is called reset noise. Unfortunately, this signal processingunit increases the contribution of thermal fluctuations by about 3 dB. To overcomethis disadvantage, a triggered low-pass filter can be added to the RDS which leadsto the IRDS cell. First, we will describe both systems, and then we will comparetheir effects, in a theoretical way and by experimentation, on the unsampled noises (i.e. the thermal and flicker noises) generated in the CCD sensor.

Ferrofluids are colloidal solutions of iron oxide magnetic nanoparticles in either a polar or no polar liquid. We present here two biological applications using maghemite (γFe2O3) ferrofluids: magnetic cell sorting and magnetocytolysis.The first application employs magnetic particles binding a biological effector, which is capable to recognize the target cells specifically. These cells become magnetic and can be sorted in a gradient of magnetic field. We describe first the various steps of the synthesis of a biocompatible ferrofluid and the grafting an effector protein onto the particles. We then describe the use of particles carrying annexin V in the separation and quantification of damaged erythrocytes in blood samples. This very sensitive technique can be used to follow the erythrocytes ageing of normal blood samples during their storage under blood bank conditions or to detect the membrane modifications that are associated with some pathologies such as malaria or Alzheimer's disease.The dependence of the magnetic susceptibility versus the frequency is a way to transform magnetic energy into thermal energy. Magnetocytolysis is the destruction of cells, carrying magnetic particles, through the action of an alternating magnetic field (about 1 MHz). We present here preliminary experiments with macrophages, which demonstrate the method's feasibility and the formation of the non-specific interactions between the cells and the magnetic particles.