Search results for "MgO"
showing 10 items of 20 documents
Comparative theoretical study of the Ag–MgO (100) and (110) interfaces
1999
We have calculated the atomic and electronic structures of Ag–MgO(100) and (110) interfaces using a periodic (slab) model and an ab initio Hartree–Fock approach with a posteriori electron correlation corrections. The electronic structure information includes interatomic bond populations, effective charges, and multipole moments of ions. This information is analyzed in conjunction with the interface binding energy and the equilibrium distances for both interfaces for various coverages. There are significant differences between partly covered surfaces and surfaces with several layers of metal, and these can be understood in terms of electrostatics and the electron density changes. For complet…
Depth profiles of damage creation and hardening in MgO irradiated with GeV heavy ions
2019
This work has been performed within the framework of the EUROfusion Enabling Research project: ENR-MFE19.ISSP-UL-02 “Advanced experimental and theoretical analysis of defect evolution and structural disordering in optical and dielectric materials for fusion applications”. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Activation of MORs in the VTA induces changes on cFos expression in different projecting regions: Effect of inflammatory pain.
2019
Abstract Chronic pain is a worldwide major health problem and many pain-suffering patients are under opioid based therapy. Epidemiological data show that pain intensity correlates with the risk of misuse of prescription opioids, and other drugs of abuse including alcohol. This increased vulnerability to suffer Substance Use Disorders could be, in part, caused by functional changes that occur over the mesocorticolimbic system, a brain pathway involved in reward processing and addiction. Previous data in rats revealed that inflammatory pain desensitizes mu opioid receptors (MORs) in the ventral tegmental area (VTA). As a consequence, pain alters dopamine release in the nucleus accumbens (NAc)…
Systemic administration of D-penicillamine prevents the locomotor activation after intra-VTA ethanol administration in rats.
2010
Although recently published studies seem to confirm the important role displayed by acetaldehyde (ACH), the main metabolite of ethanol, in the behavioral effects of ethanol, the origin of ACH is still a matter of debate. While some authors confer more importance to the central (brain metabolism) origin of ACH, others indicate that the hepatic origin could be more relevant. In this study we have addressed this topic using an experimental approach that combines local microinjections of ethanol into the ventral tegmental area (VTA) (which guarantees the brain origin of the ACH) to induce motor activation in rats together with systemic administration (i.p.) of several doses (0, 12.5, 25 and 50 …
Governare il Mezzogiorno. Gli alleati e l'occupazione/liberazione del Sud (1943-1945)
2015
In winter 1943 the United Stated and Britain planned the invasion of Axis-held Europe and decided to invade Sicily. A Military Government (Amgot) – which would be a model for the future Allied administration in Europe – was set in order to administrate the occupied territories. While the Allied propaganda presented the invasion of Italy as a «liberation» from the Axis yoke, when in summer 1943 the Allied troops landed in Sicily, Italy was actually treated as a fully-fledged enemy country. When the Amgot became operative, the contradictory role of the Allies in the occupation emerged clearly. The aim of this article is to examine the complex aspects of this military occupation in Sicily an…
Dissociative adsorption of water on Au/MgO/Ag(001) from first principles calculations
2015
Abstract The molecular and dissociative adsorption of water on a Ag-supported 1 ML, 2 ML and 3 ML-a six atomic layer-thick MgO films with a single Au adatom is investigated using density functional theory calculations. The obtained results are compared to a bulk MgO(001) surface with an Au atom. On thin films the negatively charged Au strengthens the binding of the polar water molecule due to the attractive Au–H interaction. The adsorption energy trends of OH and H with respect to the film thickness depend on an adsorption site. In the case OH or H binds atop Au on MgO/Ag(001), the adsorption becomes more exothermic with the increasing film thickness, while the reverse trend is seen when th…
First principles simulations of 2D Cu superlattices on the MgO(0 0 1) surface
2004
AbstractFirst principles slab simulations of copper 2D superlattices of different densities on the perfect MgO(001) surface are performed using the DFT method as implemented into the CRYSTAL98 computer code. In order to clarify the nature of interfacial bonding, we consider regular 1/4, 1/2 and 1 monolayer (ML) coverages and compare results of our calculations with various experimental and theoretical data. Our general conclusion is that the physical adhesion associated with a Cu polarization and charge redistribution gives the predominant contribution to the bonding of the regular Cu 2D layer on the MgO(001) surface.
About the reliability of the Maximum Entropy Method in reconstructing electron density: the case of MgO
2006
Abstract The reliability of the Maximum Entropy Method (MEM) to reconstruct finite temperature electron density (ED) is here discussed, investigating the case of periclase (MgO). A theoretical electron density has been generated by quantum mechanic calculations and folded with a function simulating atomic thermal motion, in order to produce a reference errorless ED [ρ(r)REF]. The Fourier coefficients of ρ(r)REF have been calculated, and used as “observed” diffraction intensities to reconstruct via MEM the original ED. The electron density attained by MEM [ρ(r)MEM] and ρ(r)REF have been compared with each other (pixel-by-pixel and critical points) to assess the ability of MEM to retrieve EDs…
Binding of [3H][D-Ala2, MePhe4, Gly-ol5] Enkephalin, [3H][D-Pen2, D-Pen5]Enkephalin, and [3H]U-69,593 to Airway and Pulmonary Tissues of Normal and S…
1997
Abstract Bhargava, H. N., V. M. Villar, J. Cortijo and E. J. Morcillo. Binding of [3H][D-Ala2, MePhe4, Gly-ol5]enkephalin, [3H][D-Pen2, D-Pen5]enkephalin, and [3H]U-69,593 to airway and pulmonary tissues of normal and sensitized rats. Peptides 18(10) 1603–1608, 1997.—The role of endogenous opioid peptides in the regulation of bronchomotor tone, as well as in the pathophysiology of asthma is uncertain. We have studied the binding of highly selective [3H]labeled ligands of μ-([D-Ala2, MePhe4, Gly-ol5]enkephalin; DAMGO), δ ([D-Pen2, D-Pen5]enkephalin; DPDPE), and κ-(U-69,593) opioid receptors to membranes of trachea, main bronchus, lung parenchyma and pulmonary artery obtained from normal (uns…
Regional differences in mu-opioid receptor-dependent modulation of basal dopamine transmission in rat striatum
2016
Abstract The nigrostriatal dopamine system is implicated in the regulation of reward and motor activity. Dopamine (DA) release in dorsal striatum (DS) is controlled by the firing rate of DA neurons in substantia nigra pars compacta. However, influences at terminal level, such as those involving activation of mu opioid receptors (MORs), can play a key role in determining DA levels in striatum. Nonetheless, published data also suggest that the effect of opioid drugs on DA levels may differ depending on the DS subregion analyzed. In this study, in vivo microdialysis in rats was used to explore this regional dependence. Changes in basal DA levels induced by local retrodialysis application of DA…