31 research outputs found
Serum Leptin, IGF-I and Insulin Levels in Preterm Infants Receiving Parenteral Nutrition During the First Week of Life
The emergence of multifrequency force microscopy
Atomic force microscopy uses the deflection of a cantilever with a sharp tip to
examine surfaces, and conventional dynamic force microscopy involves the
excitation and detection of a single frequency component of the tip’s motion.
Information about the properties of a sample is, however, encoded in the motion
of the probe and the dynamics of the cantilever are highly nonlinear. Therefore,
information included in the other frequency components is irreversibly lost.
Multifrequency force microscopy involves the excitation and/or detection of
several frequencies of the probe’s oscillation, and has the potential to overcome
limitations in spatial resolution and acquisition times of conventional force
microscopes. It could also provide new applications in fields such as energy
storage and nanomedicine. Here we review the development of multifrequency
force microscopy methods, highlighting the five most prominent approaches. We
also examine the range of applications offered by the technique, which include
mapping the flexibility of proteins, imaging the mechanical vibrations of carbonbased
resonators, mapping ion diffusion, and imaging the subsurface of cells.We are grateful for financial support from the Ministerio de Ciencia e Innovación (CSD2010-00024, MAT2009-08650).Peer reviewe