Blue light emitting graphene-based materials and their use in generating white light

It has been demonstrated that acid-treated graphene samples as well as reduced graphene oxide show fairly intense blue emission centered around 440 nm. Reduction of graphene oxide can be carried out either chemically or by using different types of radiations. Blue emission from graphene-based materials can be combined with the yellow emission from materials like ZnO to produce white light sources.     

Iterative in situ click chemistry assembles a branched capture agent and allosteric inhibitor for Akt1

We describe the use of iterative in situ click chemistry to design an Akt-specific branched peptide triligand that is a drop-in replacement for monoclonal antibodies in multiple biochemical assays. Each peptide module in the branched structure makes unique contributions to affinity and/or specificity resulting in a 200 nM affinity ligand that efficiently immunoprecipitates Akt from cancer cell lysates and labels Akt in fixed cells. Our use of a small molecule to preinhibit Akt prior to screening resulted in low micromolar inhibitory potency and an allosteric mode of inhibition, which is evidenced through a series of competitive enzyme kinetic assays. To demonstrate the efficiency and selectivity of the protein-templated in situ click reaction, we developed a novel QPCR-based methodology that enabled a quantitative assessment of its yield. These results point to the potential for iterative in situ click chemistry to generate potent, synthetically accessible antibody replacements with novel inhibitory properties.     

Protonation of phenylboronic acid: Comparison of G3B3 and G2MP2 methods

G3B3 and G2MP2 calculations using Gaussian 03 have been carried out to investigate the protonation preferences for phenylboronic acid. All nine heavy atoms have been protonated in turn. With both methodologies, the two lowest protonation energies are obtained with the proton located either at the ipso carbon atom or at a hydroxyl oxygen atom. Within the G3B3 formalism, the lowest‐energy configuration by 4.3 kcal · mol^?1 is found when the proton is located at the ipso carbon, rather than at the electronegative oxygen atom. In the resulting structure, the phenyl ring has lost a significant amount of aromaticity. By contrast, calculations with G2MP2 show that protonation at the hydroxyl oxygen atom is favored by 7.7 kcal · mol^?1. Calculations using the polarizable continuum model (PCM) solvent method also give preference to protonation at the oxygen atom when water is used as the solvent. The preference for protonation at the ipso carbon found by the more accurate G3B3 method is unexpected and its implications in Suzuki coupling are discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Rare earth trisoxalatocobaltates(III) a precursor for rare earth cobaltites(III)

Rare earth cobalties, LnCoO₃, can be conveniently prepared by the thermal decomposition of the precursor LnCo(C₂O₄)₃·nH₂O (La, Ce, n=9; Pr, Nd, n=8). CeCo(C₂O₄)₃·8H₂O, unlike the other oxalato compounds thermally decompose to a mixture of CeO₂ and Co₃O₄. Although LnCoO₃are formed from the precursors at a temperature lower than 800°C, thermal analysis of a mixture of La₂(C₂O₄)₃·10H₂O and CoC₂O₄·2H₂O at 900·C shows the residue containing mainly La₂O₃ and Co₃O₄ with a small amount of LaCoO₃.     

Mathematical modelling of heat conduction in certain functionally graded composites

The aim of contribution is to formulate a certain extended version of the tolerance modelling technique for functionally graded composites. For the sake of simplicity, the considerations are restricted to the bidirectionally graded heat conductors. It is shown that the proposed approach enables to determine an entire class of mathematical models for which applications can be found in various specific problems. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Quantum deformation of the confined Hulthen problem

A scheme for studyingq deformed quasi exactly solvable problem has been applied to the Schrödinger Hulthen problem (l=0). It is found that for the confined Hulthen problem, the confining parameter can be related to the deformation parameterq.     

Anisotropic Strange Star in 5D Einstein-Gauss-Bonnet Gravity

In this paper, we investigated a new anisotropic solution for the strange star model in the context of 5D Einstein-Gauss-Bonnet (EGB) gravity. For this purpose, we used a linear equation of state (EOS), in particular pr=βρ+γ, (where β and γ are constants) together with a well-behaved ansatz for gravitational potential, corresponding to a radial component of spacetime. In this way, we found the other gravitational potential as well as main thermodynamical variables, such as pressures (both radial and tangential) with energy density. The constant parameters of the anisotropic solution were obtained by matching a well-known Boulware-Deser solution at the boundary. The physical viability of the strange star model was also tested in order to describe the realistic models. Moreover, we studied the hydrostatic equilibrium of the stellar system by using a modified TOV equation and the dynamical stability through the critical value of the radial adiabatic index. The mass-radius relationship was also established for determining the compactness and surface redshift of the model, which increases with the Gauss-Bonnet coupling constant α but does not cross the Buchdahal limit.     

Almost strict competitiveness in extensive games

We consider an extension of an almost strictly competitive game, introduced by Aumann (1961), inn-person extensive games by incorporating Selten's subgame perfection. We call it a subgame perfect weakly-almost (SPWA) strictly competitive game, in particular, an SPWA strictly competitive game in strategic form is simply called a WA strictly competitive game. We give some general results on the structure of this class of games. One result gives an easy way to verify almost strict competitiveness of a given extensive game. We show that a two-person weakly unilaterally competitive extensive game, introduced by Kats and Thisse (1992) for normal form games, is SPWA strictly competitive. We remark that some of our main results for SPWA strictly competitive games do not hold for the modification of almost strict competitiveness with trembling-hand perfection.The author is indebted to Mamoru Kaneko for valuable discussions, comments and criticism throughout the paper. He thanks N. Bose, M. Frascatore, R. Gilles, H. Haller, A. Kats, J. Kline and an anonymous referee for helpful comments on earlier drafts. The usual disclaimer applies.     

Bimolecular photoreduction of aromatic sulfoxides.

Photolysis of aromatic sulfoxides in the presence of alkoxides in alcoholic solvents provides a photochemical route to the corresponding sulfides. Other electron donors also give sulfide with various degrees of success. The reaction could also be carried out using carbazoles as sensitizers, and quantitative yields could be obtained using N-methylcarbazole in methanol. Evidence points toward a hydroxysulfuranyl radical as the key intermediate, and solvent effects point to heterolysis, rather than homolysis, as the step that breaks the S-O bond.     

Samarium Barbier reactions of alpha-iodomethyloxazoles and thiazoles with aliphatic aldehydes

[reaction: see text] The reductive coupling of substituted alpha-iodomethyloxazoles and thiazoles with aliphatic aldehydes under Barbier conditions provides an effective method for the direct incorporation of intact heterocyclic systems.