Synthesis and evaluation as NOP ligands of some spiro[piperidine-4,2'(1'H)-quinazolin]-4'(3'H)-ones and spiro[piperidine-4,5'(6'H)-[1,2,4]triazolo[1,5-c]quinazolines

Some spiro[piperidine-4,2'(1'H)-quinazolin]-4'(3'H)-ones 3 and spiro[piperidine-4,5'(6'H)-[1,2,4]triazolo[1,5-c]quinazolines] 4 were synthesized and evaluated as ligands of the nociceptin receptor. The examined compounds showed partial agonistic activity, except compounds 3, 4n that proved to be pure antagonists.     

Computer-aided molecular design of asymmetric pyrazole derivatives with exceptional enantioselective recognition toward the Chiralcel OJ-H stationary phase

A computer-aided design of novel asymmetric pyrazoles with improved enantioselective properties was performed by docking experiments starting from a model of Chiralcel OJ chiral in the stationary phase. Synthesis and HPLC experiments confirmed the theoretical prediction and led to a detailed investigation of the enantioselective recognition process. For the first time, looking at the time spent by each enantiomer in contact with the CSP during long molecular dynamic simulations, the experimental analytical trend has been reproduced.     

Synthesis of TiO2 rutile nanoparticles by PLA in solution

This paper describes the synthesis of TiO₂ nanoparticles by laser ablation in solution synthesis (Lasis). The laser excimer beam passes through a focusing lens and it is sent to the reaction chamber. The frequency used during the synthesis was 20 Hz, intensity 26 kV The metal ablated by the laser beam undergoes an oxidation process resulting from the reaction with water. We obtain TiO₂ nanoparticles with average size of 6.5 nm, crystallized in the rutile structure. The crystallographic and morphological structure was studied by transmission electron microscopy.     

Influence of the support and precursor compounds on the sintering and coking of supported nickel oxyreforming catalysts

In this paper the activity, selectivity and mainly stability of nickel catalysts in the oxyreforming reaction are analyzed. The catalysts were prepared employing different precursors (nickel nitrate and nickel acetylacetonate) on α-Al₂O₃ and α-Al₂O₃ modified by a layer of aluminium oxide. The catalytic sample obtained from nickel acetylacetonate on the modified support showed the best stability.     

Skeletal vibrations of cuprate superconductor-like phases: a comparison of the FT-FIR spectra of La2−x Sr x CuO4, Nd2−x Ce x CuO4 and RBa2 Cu3 O7−x (R=Ln or Y) Powders

Il Nuovo Cimento D - The FT-IR/FT-FIR spectra of powders of Nd2−x Ce x CuO4 and La2−x Sr x CuO4 solid solutions and of RBa2Cu3O7−x with R=Y, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm and...     

Daughter ion mass spectra of 11-pentafluorobenzyl ester derivatives of 11-dehydiothromboxane B2 and B3

Collisionally activated decomposition (CAD) mass spectra of the [M – C₆F₅CH₂?]^? ions of 1-methyl cster-11-pentafluorobenzyl ester-9,12,15-tris(trimethylsilyl) and 9,12,15-tris(ethyldimethylsilyl) ether derivatives of 11-dehydrothromboxane B₂ are presented and discussed. The spectra are interpreted with the aid of those of a corresponding 3,3,4,4-tetradeutero compound and of an analogous derivative of 11-dehydrothromboxane B₃. Proposed fragmentation pathways are based on internal consistency of data from all four compounds. The migration of a trimethylsilyl or an ethyldimethylsilyl group is the salient feature of all the CAD spectra.     

On the large-N limit of 3D and 4D hermitian matrix models

The large-N limit of the hermitian matrix model in three and four euclidean space-time dimensions is studied with the help of the approximate Renormalization Group recursion formula. The planar graphs contributing to wave-function, mass and coupling-constant renormalization are identified and summed in this approximation. In four dimensions the model fails to have an interacting continuum limit, but in three dimensions there is a non-trivial fixed point for the approximate RG relations. The critical exponents of the three-dimensional model at this fixed point are ν = 0.67 and η = 0.20. The existence (or non-existence) of the fixed point and the critical exponents display a fairly high degree of universality since they do not seem to depend on the specific (non-universal) assumptions made in the approximation.