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The main objective of the present study was to determine the minimal optical deviation responsible for cognitive after-effects in healthy individuals and to explore whether there was a relationship between the degree of optical deviation and cognitive after-effects. Therefore different leftward optical deviations (8°, 10° and 15°) were used in three different groups of healthy participants. Sensorimotor after-effects (evaluating the visuo-manual realignment) were assessed using an open-loop pointing task and cognitive after-effects (evaluating changes in spatial representation) were assessed using manual and perceptual (landmark) line bisection tasks. Results revealed that exposure to 8°, 10° and 15° optical shifts produced sensorimotor after-effects. In contrast, the occurrence of cognitive after-effects depended on the optical deviation. Adaptation to an 8° leftward optical deviation did not produce cognitive after-effects. Adaptation to a 10° leftward optical deviation was responsible for after-effects in the manual line bisection task only. Adaptation to a 15° leftward optical deviation produced after-effects in both the manual and perceptual line bisection tasks. All cognitive after-effects were rightward and were similar to mild, neglect-like manifestations. Both sensorimotor and cognitive after-effects were correlated with the degree of optical deviation. Our results are of methodological and theoretical interest to those interested in sensorimotor plasticity and spatial cognition. [ABSTRACT FROM AUTHOR]

Abstract: To gain insight into how fluorination of ligands alters the C–H and C–C reductive elimination from Pt(IV) octahedral complexes, metadynamics and static DFT calculations have been performed. We compare the C–H and C–C reductive elimination from Pt(IV) octahedral complexes L2Pt(CH3)3X (X=H or CH3, L2 diphosphine ligand, viz=model of dppe and dppbz ligand and its fluorinated versions). The use of metadynamics simulations is shown to be a powerful tool to describe the reactivity of organometallic compounds, and provide us with the activation free energy of the different processes involved in these reactions: ligand dissociation, C–C and C–H formation. The structural data for the complexes are compared and in the fluorinated complexes, the Pt–P distances are significantly shorter even if the Pt–P dissociation is less energetically demanding compared to the non-fluorinated complexes. The computed free activation energies from metadynamics calculations show that for C–H reductive eliminations direct mechanism and concerted mechanism can occur but the concerted pathway is more favorable. For the C–C reductive elimination, the dissociative pathway has been studied and the use of fluorinated complexes enhances the dissociation capability of the chelating ligand and so should improve the reactivity. We also report computed activation free energy with inclusion of the entropy effect for the dissociation of the diphosphine ligand, necessary step for the C–C reductive elimination. [Copyright &y& Elsevier]

Abstract: We have performed a detailed study of the cyclization of carbonyl groups on unactivated alkynyl-quinolines. Two cyclization modes are accessible: the exo vs. endo mode. The influence of the substituents of the alkynyl-quinolines have been studied using two examples giving different reactivity: the phenyl and the CH2OMe substituent. From an experimental point of view, the reaction occurs in basic medium and the first step of the reaction has been shown to be the formation of the hemi-acetal. Two mechanisms have been investigated with and without deprotonation of the hemi-acetal prior to the carbon–oxygen bond formation and the proton’s transfer. The influence of the solvent effects has been studied using supermolecular and continuum/supermolecular techniques. The mechanism without deprotonation of the hemi-acetal presents high barriers and the inclusion of solvent effects both with the continuum method and the supermolecular approach stresses strongly this tendency especially when phenyl substituents are used. On the other hand, the base mechanism exhibits lower barriers but solvent effects also increase these barriers, which remain quite reasonable around 15kcalmol−1. Whatever the methods used, the exo mode of reaction appears to be the kinetic pathway whereas the endo mode appears to be under thermodynamic control. [Copyright &y& Elsevier]

Rightward deviation on line bisection is considered one of the most classic clinical signs of unilateral visual neglect—a cognitive disorder of spatial processing that commonly follows right brain damage. Recently, short-term adaptation to wedge prisms has been shown to significantly reduce neglect on this and other conventional diagnostic tasks. Our previous study has shown that visuomotor adaptation in normals produces a similar pattern of directional bias on a line bisection task. Based on the good working knowledge of how neglect patients perform on different versions of the standard diagnostic task, we showed here that using leftward-deviating prisms in normals, it is possible to produce: (1) a reliable bias on line bisection, (2) a rightward specific deviation, (3) a modulation of rightward deviation, which depends on the relative spatial location of the target lines and (4) a line length effect. A final experiment confirmed that these after-effects are specific to prism adaptation rather than passive prism exposure. Collectively, these findings confirm that adaptation to left-deviating prisms in normals produces a reliable right-sided bias and as shown by a previous visuospatial judgement task, these findings cannot be adequately explained by the symmetric sensori–motor effects of prism adaptation. Taken together with the improvement of spatial neglect shown by right-deviating prisms only, the present study suggests that low level sensori–motor adaptations play a greater role in right hemisphere organisation for spatial cognition than previously thought. [Copyright &y& Elsevier]

The hydrogenation of CO 2 into high-value fuels is a potentially effective approach to reduce anthropogenic dependence on fossil fuels and effects of climate change. In this study, we evaluated the hydrogenation of CO 2 into CO and CH 4 under the electrochemical promotion of catalysis (EPOC) effect through experimental and computational studies using Ru nanoparticles. Ru nanoparticles (1–2 nm) supported on yttria-stabilized zirconia (YSZ) solid electrolyte were evaluated at 250 °C at atmospheric pressure. Under positive polarization, the methanation reaction was promoted and the competitive reverse water gas shift (RWGS) reaction was impeded. On the other hand, negative polarization resulted in suppressing permanently the methanation reaction and minimally affecting the RWGS reaction. To qualitatively rationalize the tuning of selectivity via EPOC, Density Functional Theory (DFT) computations were used to model the EPOC effect induced on the Ru (0001) surface. DFT computations uncovered that electric field effects together with a change in surface electrochemical potential between intermediates are responsible for the contrasting influence of EPOC on the CH 4 and CO formation over Ru catalysts. Image 1 [ABSTRACT FROM AUTHOR]

Abstract: Children with developmental dyslexia exhibit delayed reading abilities and various sensori-motor deficits. The way these various symptoms interact remain poorly understood. The objective of this study was twofold. First, we aimed to investigate whether postural control was impaired in dyslexic children when cognitive demands are increased. Second, we checked whether this effect could be reduced significantly by a treatment aiming to recalibrate ocular proprioception. Twelve dyslexic and fifteen treated dyslexic children (>3 months of treatment) were compared with twelve non-dyslexic children in two conditions (mean age: 11.6±2.1, 12.5±1.5 and 10.6±1.7 years respectively). In a first condition they maintained balance while fixating a point in front of them. In the second condition the postural task was combined with a silently reading one. Balance was assessed by means of a force plate. Results demonstrated that the mean velocity (i.e. the total length) of the center of pressure (CoP) displacement was increased in the reading task only for the dyslexic group. Interestingly, for the treated children, an inverse tendency was observed: the mean velocity (i.e. the total length) and the surface of the 90% confidence ellipse of the CoP displacement decreased for 13/15 patients and for 12/15 patients respectively, while performing the reading task. Values remained similar to those observed for the control children. Altogether, these results strongly suggest that cognitive demands can impair postural control in developmental dyslexia but this interaction could be normalized. These results sustain the hypothesis of a cerebellar origin for dyslexia. [Copyright &y& Elsevier]

Abstract: The 1,3-dipolar cycloadditions of cyclic nitrones to five-membered unsaturated lactones are studied. Special attention was focused on a single and double asymmetric induction when one or both components were chiral. The energies of the cycloaddition reactions are investigated through application of molecular orbital calculations at the B3LYP/6-31+G(d) theory level. A study of the different reactants’ approaches and their conformational aspects revealed the stereochemical preferences of these reactions. The results of these calculations correspond well with the previously reported experimental data. [Copyright &y& Elsevier]

Abstract: Transformation of aminoacridines into N-acridinyl-N′-alkylguanidines is described. The chosen procedure allows introduction of pendent substituents (exemplified by N,N-dimethylaminopropyl chain) into key acridinyl thioureas, thus opening the way to structural diversity. Spectroscopic study and pK a determination show that the presence of the strongly basic guanidine has a dramatic influence on the ionization of the acridine nucleus by lowering the pk a value down to 4.49. [Copyright &y& Elsevier]

Abstract: The 1,3-dipolar cycloaddition of cyclic nitrones with electron-poor and electron-rich cyclic dipolarophiles (α,β-unsaturated lactones and vinyl ethers) is studied. The energies of the cycloaddition reactions have been investigated through molecular orbital calculations at the B3LYP/6-31+G(d) level theory. Different reaction channels and reactants approaches, effective in regio- and stereochemical preferences are discussed. The results were compared with experimental data to find a good agreement. [Copyright &y& Elsevier]

Formic acid is obtained in equimolar amount with levulinic acid during the hydrolysis of cellulose and thus can be used as a sustainable hydrogen source in the direct levulinic acid hydrogenation towards gamma-valerolactone (biofuel additive). Ag Pd catalysts prepared by various methods and containing different Ag:Pd ratio were investigated in this context. By combining activity tests, characterization of the main physicochemical properties of the catalysts and DFT study of formic acid decomposition, the key factors responsible for the activity of Ag Pd catalysts in both the formic acid decomposition and the subsequent hydrogenation of levulinic acid were specified. Pd is shown to be active, but prone to poisoning by CO, while the CO poisoning remains limited on diluted Ag Pd alloy with strong intermetallic interaction, where its adsorption is very weak thanks to the isolation of Pd atoms. Therefore, the catalyst containing 4%Ag-1%Pd/AlOOH showed the highest selectivity in formic acid decomposition as well as the highest activity in levulinic acid hydrogenation (34% conversion in 5 h at 190 °C). • Pd–Ag catalysts are active in the formic acid decomposition and levulinic acid hydrogenation tandem process. • Pd–Ag catalysts are reducing CO poisoning compared to the active Pd counterpart. • Preparation method and Ag:Pd ratio allow to tune the activity of the reaction. • Periodic DFT computations were used to rationalize the activity of Pd–Ag catalysts. [ABSTRACT FROM AUTHOR]

The efficiency of direct ethanol fuel cells suffers from the partial oxidation of ethanol into acetic acid as opposed to the complete oxidation of this fuel to CO 2 . Herein, we support the quest for a selective catalyst for ethanol electro-oxidation to CO 2 , building on our previous mechanistic hypothesis based on experimental insight and DFT computations. We derive a simple descriptor of the expected selectivity towards full oxidation, Ω, as a function of the adsorption energy of atomic C and O. Three different families of catalyst surfaces are screened using this descriptor: monometallics, bimetallics and conducting metal oxides, totaling to 600 surfaces. In agreement with available experimental data, no single metal surface is more selective for total oxidation than platinum and palladium. While the selected conducting oxides were not predicted to be selective towards splitting the C C bond, structurally-controlled monometallics (such as Pd(100)) or some bimetallics (Pd 3 Ag) are found to be competitive with the most stable facet, (111), of Pd and Pt. Despite this very extensive screening, no very promising catalyst has been identified. This highlights the need to identify catalysts for acetate oxidation or to exploit support effects and electrolyte engineering to profit from the full power of direct ethanol fuel cells. [ABSTRACT FROM AUTHOR]

Bulk (Mo 2 N) and supported molybdenum nitride (Mo 2 N/TiO 2 , Mo 2 N/CeO 2) were synthesized by reduction-nitridation of bulk and supported MoO 3 under a mixture of N 2 /H 2. We investigated the mechanism of formation of molybdenum nitrides by coupling elemental analysis, in situ and ex situ XRD, Raman spectroscopy, in situ XPS/UPS spectroscopy and DFT calculation. We showed that it is possible to control the crystallographic phase and degree of nitridation (i.e. nitrogen vacancies) by adjusting the parameters of the synthesis, including the heating rate and final temperature, the nature, composition and flow of gas during reduction/nitridation and cooling. We demonstrated that β-Mo 2 N and γ-Mo 2 N go through the same intermediates: molybdenum bronze, MoO 2 and Mo. The final crystallographic phase of the nitride depends mainly on the temperature rate and gas hourly space velocity employed during the synthesis, as they impact the crystallite size of the intermediates and the kinetics of reduction and nitridation. Molybdenum nitride clusters (<0.5 nm) are formed on TiO 2. [Display omitted] • Mechanism of formation of tetragonal and cubic molybdenum nitride with N 2 /H 2. • Identification of molybdenum bronze (H x MoO 3) as a new intermediate. • Controlling the crystallographic phase and nitrogen content of molybdenum nitride. • In situ X-ray and Ultraviolet photoelectron spectroscopy coupled with DFT calculation. • Synthesis of small clusters (<0.5 nm) of Mo 2 N on TiO 2. [ABSTRACT FROM AUTHOR]

Reaction of Fe(NO 3 ) 3 with 3,6-di(pyrimidin-2-yl)-1,2,4,5-tetrazine (BPymTz) in acetonitrile gives a hepta-coordinated Fe III complex ( 1 ) with the bridging unit 1,2-diiminohydrazido (1,2-dih 2− : − HN C(R) N N C(R) NH − ) generated in situ from the tetrazine ring-opening of BPymTz. DFT calculations, X-ray diffraction studies and SQUID magnetometry measurements were successfully performed on 1 . The crystallography measurement confirms the ring-opening and the substituent’s contribution to the rare pentagonal bipyramidal coordination geometry of the metal ions. Magnetic susceptibility measurements on 1 reveal an S = 0 ground state, arising from the antiferromagnetic interaction between the two Fe III centers ( J = −3.02 cm −1 ) within the molecule. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rightward bias for central location in children with dyslexia in line bisection. [•] Asymmetrical effect of line location in children with dyslexia. [•] Lateral effect towards the starting position in proprioceptive circle centering. [•] Forward (backward) effect in visuo-proprioceptive (proprioceptive) circle centering. [•] Influence of the left starting position in radial response in children with dyslexia. [Copyright &y& Elsevier]

To improve lubricant formulation, a better understanding of the wettability properties and hence of the interactions between the surface and the lubricant additives is a key parameter. Herein, we use density functional theory calculations to characterize 32 typical head groups, classified into four categories: protic, aprotic, aromatic and phosphorus-containing molecules. By comparing their adsorption energies on γ-alumina, used as a surface model of aluminium sheets, and their solvation energies in a model lubricant base oil, we found that the solvation energy was not a discriminant parameter while the adsorption energy was critical. Phosphates and carboxylic acids are the most strongly adsorbed, and thus more likely to yield to improved wettability properties of the lubricant through film formation. Image 1 • Ab initio modelling unravels the wettability related competition between solvation and adsorption for lubricant additives. • For lubricants in apolar base oils, the solvation is not critical while the adsorption strength discriminates the additives. • A linear correlation is obtained between the dissociative adsorption energy and the pKa of the head group of the additive. • Phosphates and carboxylic acids are the most adsorbed functional groups and should improve the wettability properties. [ABSTRACT FROM AUTHOR]