A general route to synthesize supported isolated oxide and mixed-oxide nanoclusters at sizes below 5 nm

A simple and efficient route to prepare supported nanocrystalline oxides is presented. The synthesis procedure, i.e. in situ autocombustion of a glycine complex, allows the production of nanocrystals in a porous matrix presenting larger pore size. An example of successful formation of 2-5 nm nanocrystals is given for a single oxide (Fe(2)O(3)), a mixed-oxide structure (LaCoO(3) perovskite-type) and a nickel-doped oxide.     

Improved intermediate asymptotics for the heat equation

This letter is devoted to results on intermediate asymptotics for the heat equation. We study the convergence towards a stationary solution in self-similar variables. By assuming the equality of some moments of the initial data and of the stationary solution, we get improved convergence rates using entropy/entropy-production methods. We establish the equivalence of the exponential decay of the entropies with new, improved functional inequalities in restricted classes of functions. This letter is the counterpart in a linear framework of a recent work on fast diffusion equations; see Bonforte et al. (2009) [18]. The results extend to the case of a Fokker–Planck equation with a general confining potential.     

Isolation of mineralizing Nestin+ Nkx6.1+ vascular muscular cells from the adult human spinal cord

Background

Evidence suggests that rheumatoid arthritis (RA) may enhance or reduce the progression of Alzheimer's disease (AD). The present study was performed to directly explore the effects of collagen-induced rheumatoid arthritis (CIA) on amyloid plaque formation, microglial activation, and microvascular pathology in the cortex and hippocampus of the double transgenic APP/PS1 mouse model for AD. Wild-type or APP/PS1 mice that received type II collagen (CII) in complete Freund's adjuvant (CFA) at 2 months of age revealed characteristics of RA, such as joint swelling, synovitis, and cartilage and bone degradation 4 months later. Joint pathology was accompanied by sustained induction of IL-1β and TNF-α in plasma over 4 weeks after administration of CII in CFA.

Results

CIA reduced levels of soluble and insoluble amyloid beta (Aβ) peptides and amyloid plaque formation in the cortex and hippocampus of APP/PS1 mice, which correlated with increased blood brain barrier disruption, Iba-1-positive microglia, and CD45-positive microglia/macrophages. In contrast, CIA reduced vessel density and length with features of microvascular pathology, including vascular segments, thinner vessels, and atrophic string vessels.

Conclusions

The present findings suggest that RA may exert beneficial effects against Aβ burden and harmful effects on microvascular pathology in AD.     

On the degree of the inverse of an automorphism of the affine space

We study the degree of the inverse of an automorphism f of the affine n-space over a -algebra k, in terms of the degree d of f and of other data. For n = 1, we obtain a sharp upper bound for deg (f^{− 1}) in terms of d and of the nilpotency index of the ideal generated by the coefficients of f^′'. For n = 2 and arbitrary d≥ 3, we construct a (triangular) automorphism f of Jacobian one such that deg(f^{− 1}) > d. This answers a question of A. van den Essen (see [3]) and enables us to deduce that some schemes introduced by authors to study the Jacobian conjecture are not reduced. Still for n = 2, we give an upper bound for deg (f^{− 1}) when f is triangular. Finally, in the case d = 2 and any n, we complete a result of G. Meisters and C. Olech and use it to give the sharp bound for the degree of the inverse of a quadratic automorphism, with Jacobian one, of the affine 3-space.     

Synthèses et applications des oxophosphonates en chimie organique

Synthesis and affliations of oxophosphonates in organic chemistry. This work devoted to oxophosphonates deals with three different series of compounds: the α-ketophosphonates, the β-ketophosphonates and finally the γ- and δ-ketophosphonates which were considered as one series of compounds. For each type of products, the various synthetic methods as well as their reactivity were presented. In the last part, we have developed different methods of reduction, nucleophilic addition and substitution reactions. Particular attention was focused on sulfur and nitrogen containing derivatives as well as fluorinated and chlorinated compounds.     

Temperature Determination in Air Plasmas with Chlorofluorocarboned Molecules in the Range 2500 K < T < 6000 K: Application to Quantitative Analysis of Elemental Pollutants

The diagnosis by emission spectroscopy of quasi-thermal air plasmas mixed with pollutants was performed for temperatures lower than 6000 K at atmospheric pressure. The applications concern monitoring of the destruction of chlorofluorocarbons (CFC) and the measurement of very low concentrations (some ppb) of heavy metals (copper) in air. The proposed methods are based on the simulation of the absolute intensity of the most intense molecular systems of the spectra (systems Gamma of NO, A-X of OH and NH, Schumann–Runge of O₂ and violet of CN). The plasma composition of the mixtures (air+x% H₂O+y% Cu+z% CCl₂F₂) and spectra simulation takes into account non-thermal equilibrium (T_g and T_e kinetic temperatures of gas and electrons with X=T_e/T_g). Six methods were selected and the conditions for their use were discussed. They were applied to the diagnosis of an air Inductively Coupled Plasma (64 MHz, 2.4 kW). Excellent agreement was obtained among them. Temperature variations lower than 50 K were able to be revealed and temperatures lower than 2600 K were measured. In a spectroanalysis context, it was shown that the partial pressure of metal nebulized in the discharge is uniform and that its excitation temperature T_Cu=T_g. The copper concentration was measured with an uncertainty which does not exceed 7%.     

凝结相中功能性碳材料和碳纳米复合物催化转化生物质制备可再生化学品(英文)

The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures ( 300 °C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.     

Calix[6]arene mono-diazonium salt synthesis and covalent immobilization onto glassy carbon electrodes

This Letter describes the fast synthesis of a mono-aminated calix[6]arene. The immobilization of this macrocycle onto glassy carbon electrodes via diazonium salt chemistry and the electrochemical characterization of the grafted organic layer are also reported.