Biomimetic total synthesis of meiogynin A, an inhibitor of Bcl-xL and Bak interaction

A short, convergent, and selective synthesis of meiogynin A, an inhibitor of the antiapoptotic protein Bcl-xL, has been performed. This synthesis, based on a biomimetic approach, allowed the determination of its absolute configuration. Three isomers of meiogynin A have also been elaborated. One of these was found to be three times more potent than the natural compound.     

Excess properties and vapour pressure of {3-diethylaminopropylamine + cyclohexane}

The vapour pressures of liquid {3-diethylaminopropylamine (3-DEPA) + cyclohexane} were measured by a static method between T = (273.15 and 363.15) K at 10 K intervals. The excess molar volumes V^E at 298.15 K and excess molar enthalpies H^E at 303.15 K were also measured. The molar excess Gibbs free energies G^E were obtained with Barker’s method and fitted to the Redlich–Kister equation. The Wilson equation was also used. Deviations between experimental and predicted G^E and H^E, by using DISQUAC model, were evaluated     

Measurement and prediction of (solid + liquid) equilibria of gun powder’s and propellant’s stabilizers mixtures

A differential scanning calorimetry (d.s.c.) was used to determine binary (solid + liquid) phase equilibria (SLE) for four binary mixtures, viz. (n-nitrosodiphenylamine + diphenylamine), (2-nitrodiphenylamine + ethyl centralite), (2,4-dinitro-N-ethylaniline + methyl centralite), and (2,4-diphenylamine + 4,4′-dinitroethylcentralite). These compounds are used as stabilizers in gun powders and propellants. Results obtained with this technique are compared with those correlated by NRTL and ideal models. It was found out that all the systems are simple eutectic systems and deviations between experimental and predicted SLE results were observed.     

Quantum Transport in Crystals: Effective Mass Theorem and K·P Hamiltonians

In this paper the effective mass approximation and the k·p multi-band models, describing quantum evolution of electrons in a crystal lattice, are discussed. Electrons are assumed to move in both a periodic potential and a macroscopic one. The typical period e{\epsilon} of the periodic potential is assumed to be very small, while the macroscopic potential acts on a much bigger length scale. Such homogenization asymptotic is investigated by using the envelope-function decomposition of the electron wave function. If the external potential is smooth enough, the k·p and effective mass models, well known in solid-state physics, are proved to be close (in the strong sense) to the exact dynamics. Moreover, the position density of the electrons is proved to converge weakly to its effective mass approximation.     

Search for a standard model Higgs boson in the H→ZZ→ℓ(+)ℓ(-)νν decay channel with the ATLAS detector

A search for a heavy standard model Higgs boson decaying via H→ZZ→→?(+)?(-)νν, where ?=e, μ, is presented. It is based on proton-proton collision data at √s=7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb(-1). The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340相似文献   

Geometries and electronic structures of Ga<Subscript>2</Subscript>Se<Subscript>3</Subscript>, Ga<Subscript>3</Subscript>Se<Subscript>2</Subscript> and their anions. Theoretical insights

We hereby report a theoretical study on the equilibrium geometries, electronic structures and harmonic vibrational frequencies of Ga₂Se₃, Ga₃Se₂ and their anions. The ground and low-lying excited states of Ga₂Se₃⁻, Ga₂Se₃, Ga₃Se₂⁻ and Ga₃Se₂ are studied at the B3LYP and/or MP2 and CCSD(T) levels in conjunction with 6-311+G(d) and 6-311+G(2df) one particle basis sets. Ga₂Se₂⁻ adopts the C_2v kite geometry while Ga₂Se₃ has a ‘V’ geometry. Ga₃Se₂⁻ has a three-dimensional ‘D_3h ’ geometry and Ga₃Se₂ prefers the three-dimensional ‘C_2v ’ structure. Electron detachment energies from the ground electronic states of the anions to several neutral states are reported and discussed. At CCSD(T)//MP2 level, the adiabatic electron affinity (AEA) of Ga₂Se₃ is calculated to be 3.23 eV when using the 6-311+G(2df) basis set and that of Ga₃Se₂ is 2.77 eV with the 6-311+G(d) basis set. The findings of this research are analyzed and compared with gallium oxide and sulfide analogues.     

Interaction in the geometro-differential conception of extended particles and the Galilei semigroup of trajectories

Along the lines of a previous work, the geometrical structure of Hibert bundles describing extended quantum free particles is repeated with Galilei external and internal independent symmetries. Then, in order to introduce the interaction, this structure is extended by replacing configuration and momentum spaces by the socelled spaces of trajectories and extended velocity boosts, respectively. These provide representations giving the probability amplitudes for the particle to follow certain trajectories. The interaction can be introduced in the transformation law from functions on the space of trajectories (free dynamics) to functions on spacetime (intracting dynamics). This transformation law, which makes use of a universal distribution, is seen as a functional in our work according to a quantum functional theory which generalizes the ideas of de Broglie. Intertwining of induced representations gives the free propagator in the space of trajectories and, henceforth, the propagator with interaction in space-time for the extended particle.     

Vapour pressures and excess functions of N, N, N′, N′-tetramethylalkanediamine + cyclohexane. A group contribution study of the N---N proximity effect

The vapour pressuresof liquid cyclohexane + N, N, N′, N′-tetramethylalkanediamine, (CH₃)₂ N(CH₂)_uN(CH₃)₂ (u = 1,2) + cyclohexane mixtures were measured by a static method between 303.15 and 343.15 K at 10 K intervals. The excess molar enthalpies at 303.15 K were also measured.

The molar excess Gibbs energies, calculated from the vapour-liquid equilibrium data, and the molar excess enthalpies compare satisfactorily with group contribution (DISQUAC) predictions.

The proximity effect of N atoms produces a regular decrease of the interactional parameters.     

Atheroprotective potentials of curcuminoids against ginger extract in hypercholesterolaemic rabbits

The anti-atherogenic potentials of total ginger (Zingiber officinale) extract (TGE) or curcuminoids extracted from turmeric (Curcuma longa), members of family Zingiberaceae, were compared in hypercholesterolaemia. Rabbits were fed either normal or atherogenic diet. The rabbits on atherogenic diet received treatments with TGE or curcumenoids and placebo concurrently for 6 weeks (n = 6). The anti-atherogenic effects of curcuminoids and ginger are mediated via multiple mechanisms. This effect was correlated with their ability to lower cholesteryl ester transfer protein activity. Ginger extract exerted preferential effects on plasma lipids, reverse cholesterol transport, cholesterol synthesis and inflammatory status. Curcuminoids, however, showed superior antioxidant activity.