No abstract

Our results indicate that learning tasks of reading aloud and arithmetic calculation can be used for cognitive rehabilitation of dementia patients.

Visualizing atoms and discriminating between those of different elements is a goal in many analytical techniques. The use of electron energy-loss spectroscopy (EELS) in such single-atom analyses is hampered by an inherent difficulty related to the damage caused to specimens by incident electrons. Here, we demonstrate the successful EELS single-atom spectroscopy of various metallofullerene-doped single-wall nanotubes (known as peapods) without massive structural destruction. This is achieved by using an incident electron probe with a low accelerating voltage (60 kV). Single calcium atoms inside the peapods were unambiguously identified for the first time using EELS. Elemental analyses of lanthanum, cerium and erbium atoms were also demonstrated, which shows that single atoms with adjacent atomic numbers can be successfully discriminated with this technique.

To reduce radiation damage caused by the electron beam and to obtain high-contrast images of specimens, we have developed a highly stabilized transmission electron microscope equipped with a cold field emission gun and spherical aberration correctors for image- and probe-forming systems, which operates at lower acceleration voltages than conventional transmission electron microscopes. A delta-type aberration corrector is designed to simultaneously compensate for third-order spherical aberration and fifth-order 6-fold astigmatism. Both were successfully compensated in both scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) modes in the range 30-60 kV. The Fourier transforms of raw high-angle annular dark field (HAADF) images of a Si[110] sample revealed spots corresponding to lattice spacings of 111 and 96 pm at 30 and 60 kV, respectively, and those of raw TEM images of an amorphous Ge film with gold particles showed spots corresponding to spacings of 91 and 79 pm at 30 and 60 kV, respectively. Er@C(82)-doped single-walled carbon nanotubes, which are carbon-based samples, were successfully observed by HAADF-STEM imaging with an atomic-level resolution.