In this work VO2 /SiO2 samples were maintained-by
heat sinking-at a selected temperature within the heating branch of the hysteresis loops for resistance and near-infrared transmittance, while brief thermal excursions of the VO2 film were caused by either voltage pulses applied to the film or laser light pulses irradiating the film. These pulses had durations from milliseconds to a few seconds and the resulting drops in resistance or transmittance were easily and repeatably measurable without appreciably affecting their new values. A sequence of equal-duration pulses (for either equal-voltage or equal-irradiation pulses) caused the resistance and infrared transmittance to continue to drop, each time by a smaller amount, and
larger energy pulses were required in order to cause drops comparable with the initial one. The ability of the film to change the values of the measurands in this manner Napabucasin concentration with additional pulses was maintained up to a limit defined by the outer hysteresis curve for the measurand in question. The results presented show that a plurality of memory “”states”" in VO2 can be established or “”written”" either by voltage pulses or by light pulses applied to the material, and queried or “”read”" by resistance or transmittance readings, or both. These states were found to remain stable for at least several hours, as long as temperature was kept constant, Dehydrogenase inhibitor and are expected to persist indefinitely under this condition. In the all-optical case, if the same light beam is used for writing and reading the memory state, the device is an optical analog of a memristor. (C) 2010 American Institute of Physics. [doi:10.1063/1.3518508]“
“Purpose: To establish an imaging approach to visualize the 100-mu m-thick hippocampal buy AZD4547 neuron-generating dentate granule cell layer (DGCL) consistently within a clinically feasible magnetic resonance (MR) imaging duration and to assess its sensitivity by quantifying the likelihood that it will be detected in healthy young adults.
Methods: The study was HIPAA compliant and institutional review board approved. All subjects provided written informed consent. Ten healthy volunteers (five male subjects, five female subjects; mean age, 26 years +/- 6 [standard deviation]) were imaged at 7.0 T by using a 24-element head coil array with three-dimensional T1-weighted MR imaging for anatomic reference, followed by T2*-weighted gradient-echo (echo time, 25 msec; repetition time, 944 msec) imaging at 232-mu m in-plane resolution (0.05-mm(3) pixels) in coronal and sagittal slabs (17 sections at 1 mm thick) over the hippocampus in 14 minutes. The entire study took 45 minutes.
Results: The DGCL was consistently visible in all 10 enrolled subjects. All larger subfields were visible in excellent detail and contrast in every subject.
Conclusion: The spatial resolution and tissue contrast at high field strength (7.