Lipidomics Analysis Reveals Efficient Storage of Hepatic Triacylglycerides Enriched in Unsaturated Fatty Acids after One Bout of Exercise in Mice

Background: Endurance exercise induces lipolysis, increases circulating concentrations of free fatty acids (FFA) and the uptake and oxidation of fatty acids in the working muscle. Less is known about the regulation of lipid metabolism in the liver during and post-exercise

Vanadium oxide nanostructures on Rh(111): Promotion effect of CO adsorption and oxidation

The adsorption of CO and the reaction of CO with pre-adsorbed oxygen at room temperature has been studied on the (2 x 1)O-Rh(1 1 1) surface and on vanadium oxide-Rh(1 1 1) "inverse model catalyst" surfaces using scanning tunnelling microscopy (STM) and core-level photoemission with synchrotron radiation. Two types of structurally well-defined model catalyst V3O9-Rh(1 1 1) surfaces have been prepared, which consist of large (mean size of similar to 50 nm, type I model catalyst) and small (mean size < 15 nm, type II model catalyst) two-dimensional oxide islands and bare Rh areas in between; the latter are covered by chemisorbed oxygen. Adsorption of CO on the oxygen pre-covered (2 x 1)O-Rh(1 1 1) surface leads to fast CO uptake in on-top sites and to the removal of half (0.25 ML) of the initial oxygen coverage by an oxidation clean-off reaction and as a result to the formation of a coadsorbed (2 x 2)-O + CO phase. Further removal of the adsorbed O with CO is kinetically hindered at room temperature. A similar kinetic behaviour has been found also for the CO adsorption and oxidation reaction on the type I "inverse model catalyst" surface. In contrast, on the type II inverse catalyst surface, containing small V-oxide islands, the rate of removal of the chemisorbed oxygen is significantly enhanced. In addition, a reduction of the V-oxide islands at their perimeter by CO has been observed, which is suggested to be the reason for the promotion of the CO oxidation reaction near the metal-oxide phase boundary

Strain relaxation and surface morphology of nickel oxide nanolayers

The surface morphology and the lattice constants of NiO overlayers in the thickness range of 1\u201320 monolayers (NiO nanolayers) on Pd(1 0 0) have been investigated by high-resolution spot profile low-energy electron diffraction (SPA-LEED) and scanning tunneling microscopy (STM). NiO islands grow epitaxially on Pd(1 0 0) on top of a c(4 7 2) Ni3O4 monolayer with a compressed strained lattice, which relaxes gradually attaining the bulk lattice constant at 10\u201312 monolayers. The strain relaxation is accompanied by the formation of small angle mosaic defect regions at the surface, which have been characterised quantitatively by following the behaviour of the satellites to the main Bragg diffraction rods. The analysis of the diffuse scattering intensity around the (0 0) diffraction spot reveals anisotropic NiO island shapes, whose orientation depends on the growth conditions. An incommensurate superlattice in LEED and STM at intermediate NiO coverages ( 3c2\u20136 monolayers) is observed and its origin is discussed

The self-assembly of metallic nanowires

We have demonstrated that nickel adatoms self-assemble into quasi one-dimensional nanowires on vicinal Rh(111) surfaces by decorating their regular monoatomic step arrays, while V adatoms do not. The step decoration process has been followed experimentally by variable-temperature scanning tunnelling microscopy and high-resolution X-ray photoelectron spectroscopy. The physical origin of the different step-assisted self-assembly behaviour of Ni and V adatoms has been elucidated theoretically and is ascribed to different diffusion barriers and trapping capability of Ni and V at Rh steps. (c) 2006 Elsevier B.V. All rights reserved

Reactive growth of NiO ultrathin films on Pd(100): a multitechnique approach

Reactivegrowth of NiO ultrathin films on Pd(1 0 0) has been performed by evaporating metallic Ni in an oxygen atmosphere. The evolution of the ultrathin film is followed by means of low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), X-ray photoelectron diffraction (XPD) and scanning tunnelling microscopy (STM). The first monolayer (ML) of the deposited oxide develops as a completely wetting 2D overlayer with a c(4 7 2) periodicity, as shown by sharp LEED patterns and atomically resolved STM images. Further NiO deposition results in 3D NiO(1 0 0) islands formation on-top the c(4 7 2) superstructure, as shown by STM images and XPD data. Two layers thick islands are shown to be pseudomorphic to the substrate, i.e. characterised by in-plane compressive strain and interlayer expansion. LEED, XPD and STM give independent yet converging evidence that partial strain relaxation occurs within the third monolayer

V2O3(0001) surface terminations: from oxygen- to vanadium-rich

Well-ordered epitaxial V2O3(0 0 0 1) films (thickness > 80 Angstrom) have been prepared on the clean Rh(1 1 1) surface and investigated with scanning tunnelling microscopy, low-energy electron diffraction, high-resolution electron energy loss spectroscopy and high-resolution X-ray photoelectron spectroscopy with synchrotron radiation. Atomically flat V2O3(0 0 0 1) surfaces, terminated by vanadyl (V=O) groups, have been obtained after the reactive oxide deposition and subsequent annealing in vacuum to 600 degreesC. Annealing the V=O termination in oxygen atmosphere (500 degreesC, 5 x 10(-6) mbar) results in the partial removal of the vanadyl groups and in the formation of an oxygen-richer surface termination, exhibiting a (root3 x root3)R30degrees structure. Structure models for this oxygen-rich termination are proposed, which are characterised by (O=V)(0.66)-O-3-V-V-. . . and (O=V)(0.33)-O-3-V-V (. . .) stacking sequences. Conversely, deposition of sub-monolayer V coverages onto the V=O surface leads to the formation of a metal-rich V2O3(0 0 0 1) surface, terminated by a close-packed V-3 layer on top of the bulk-type O-3 plane. Such a VO(1 1 1)-layer is only metastable and oxidises back readily upon annealing in vacuum to the vanadyl-terminated V2O3(0 0 0 1) surface. (C) 2004 Elsevier B.V. All rights reserved

Chemical Reactivity of Ni-Rh Nanowires

The properties of bimetallic Ni-Rh nanowires, fabricated by decorating the steps of vicinal Rh(111) surfaces by stripes of self-assembled Ni adatoms, have been probed by STM, photoemission, and ab initio density functional theory calculations. These Ni-Rh nanowires have specific electronic properties that lead to a significantly enhanced chemical reactivity towards oxygen. As a result, the Ni-Rh nanowires can be oxidized exclusively, generating novel quasi-one-dimensional oxide structures