Direct measurement of the PSF for Coulomb delocalization - a reconsideration.

An interpretation of Coulomb delocalization, which limits the spatial resolution of inelastic TEM or STEM images, is given. We conclude that the corresponding point spread function cannot be measured as a broadening of a STEM probe.

Effect of subcutaneous insulin detemir on glucose flux and lipolysis during hyperglycaemia in people with type 1 diabetes.

AIMS: To investigate, using a novel non-steady-state protocol, the differential effects of subcutaneous (s.c.) detemir and NPH insulin on glucose flux and lipid metabolism after insulin withdrawal. METHODS: After a period of insulin withdrawal resulting in whole-blood glucose concentration of 7 mmol/l, 11 participants (five men, mean age 41.0 years, mean body mass index 25 kg/m(2)) with type 1 diabetes (mean glycated haemoglobin concentration 57 mmol/mol, mean diabetes duration 14 years) received 0.5 units per kg body weight s.c. insulin detemir or NPH insulin in random order. Stable isotopes of glucose and glycerol were infused intravenously throughout the study protocol. RESULTS: Glucose concentration decreased after insulin treatment as a result of suppression of endogenous glucose production, which occurred to a similar extent with both detemir and NPH insulin. The rate of glucose disappearance (Rd) was not increased significantly with either type of insulin. When the effect of detemir and NPH insulin on glucose flux at glucose concentrations between 9 and 6 mmol/l was examined, glucose rate of appearance (Ra) was similar with the two insulins; however, glucose Rd was greater with NPH insulin than with detemir at glucose concentrations of 8.0, 8.5, 7.0 and 6.0 mmol/l (p < 0.05) The percentage change in glycerol Ra, a measure of lipolysis, was greater in the NPH group than in the detemir group (p = 0.04). CONCLUSIONS: The results of the study are consistent with the hypothesis that detemir has a lesser effect on the periphery, as evidenced by a lesser effect on peripheral glucose uptake at specific glucose concentrations.

A low error reconstruction method for confocal holography to determine 3-dimensional properties.

A confocal holography microscope developed at the University of Victoria uniquely combines holography with a scanning confocal microscope to non-intrusively measure fluid temperatures in three-dimensions (Herring, 1997, Abe and Iwasaki, 1999, Jacquemin et al., 2005). The Confocal Scanning Laser Holography (CSLH) microscope was built and tested to verify the concept of 3D temperature reconstruction from scanned holograms. The CSLH microscope used a focused laser to non-intrusively probe a heated fluid specimen. The focused beam probed the specimen instead of a collimated beam in order to obtain different phase-shift data for each scan position. A collimated beam produced the same information for scanning along the optical propagation z-axis. No rotational scanning mechanisms were used in the CSLH microscope which restricted the scan angle to the cone angle of the probe beam. Limited viewing angle scanning from a single view point window produced a challenge for tomographic 3D reconstruction. The reconstruction matrices were either singular or ill-conditioned making reconstruction with significant error or impossible. Establishing boundary conditions with a particular scanning geometry resulted in a method of reconstruction with low error referred to as "wily". The wily reconstruction method can be applied to microscopy situations requiring 3D imaging where there is a single viewpoint window, a probe beam with high numerical aperture, and specified boundary conditions for the specimen. The issues and progress of the wily algorithm for the CSLH microscope are reported herein.

Planar diffracted-beam interferometry/holography.

A method to interfere planar electron diffracted beams that have been created by a primary electron beam passing through a crystal specimen has been invented and referred to as planar diffracted-beam interferometry/holography (planar DBI/H). Planar DBI/H is able to measure the intensity and coherence properties of the diffracted electron beams. When the diffracted electron beams are energy filtered, planar DBI/H is also able to measure the intensity and coherence properties of the zero-loss electrons, phonon-loss electrons and plasmon-loss electrons. These coherence properties are useful to help our understanding of the Stobbs factor and the properties of advanced materials, necessary for our understanding of nanoscience and the development of nanotechnology.

Energy-filtered electron-diffracted beam holography.

A method of energy-filtered electron holography is described where any two electron-diffracted beams can be interfered using an electron biprism. A Gatan image filter is used to select the energy loss of the electrons produced in the holograms. Gallium arsenide is used as the TEM specimen. This method of microscopy confirms that fringes extending beyond a limiting aperture were due to inelastically scattered electrons and specifically electrons scattered from the bulk plasmon. The degree of coherence of the zero-loss and energy-loss electrons were high and measured to be approximately 0.3, which was maintained even for the high energy-loss electrons up to 100 eV. Future systematic studies using this method should help understand the Stobbs factor and contribute to the development of quantitative high-resolution electron microscopy.