Competition between antiferromagnetism and superconductivity in high-Tc cuprates

Using variational cluster perturbation theory we study the competition between d-wave superconductivity (dSC) and antiferromagnetism (AF) in the t-t(')-t(')-U Hubbard model. Large scale computer calculations reproduce the overall ground-state phase diagram of the high-temperature superconductors as well as the one-particle excitation spectra for both hole and electron doping. We identify clear signatures of the Mott gap as well as of AF and of dSC that should be observable in photoemission experiments.     

Detection system for electro-separation analytical methods

The paper provides information about the on-line monitoring of components analysed by capillary electrophoresis. For this purposes we developed a whole-capillary transverse scanning detection system, which helps to improve and control the separation processes. A picture from a colour line scanner was used as a source of basic information for autonomous control of the separation process by regulation of the high voltage source. The application and algorithms for machine vision were designed in the progressive graphic development system LabVIEW. Real-time control of the separation process was implemented in a compact control process logic controller. The performance of the detection system was evaluated and the function of the overall system was tested by performing isotachophoretic analysis of a model mixture.     

Vecteurs totalisateurs d'une algèbre de von Neumann

We prove that the set of cyclic vectors for a von Neumann algebra in a Hilbert spaceH is aG set, which is empty or dense. We obtain some corollaries, for instance: if (A ₁,A ₂ ...) is a sequence of von Neumann algebras inH, and if eachA _n has a cyclic vector and a separating vector, then there exists a vector inH which is cyclic and separating for eachA _n. For algebras of local observables, we improve the known results connecting the infinite type of the algebras and the existence of cyclic and separating vectors.     

First lanthanide dipolar complexes for second-order nonlinear optics

New push-pull NLO-phores based on lanthanide complexes (Ln = La, Gd, Dy, Yb) featuring an annelated dibutylaminophenyl functionalised terpyridyl ligand have been synthesised and shown to exhibit large first-order hyperpolarizability.     

Analytical aspects of carrier ampholyte-free isoelectric focusing

The applicability of carrier ampholyte-free isoelectric focusing (CAF-IEF) for analyses of ampholytes is demonstrated. The suggested method is based on the principle of both side regulated ionic matrix in CAF-IEF. A sharp step of pH is created in the column filled with a sample dissolved in a background electrolyte by influence of current and solvolytic fluxes. Here, ampholytes are focused upon. The magnitude of the step, its velocity and direction of its movement can be regulated electrically. In this manner, favorable separation properties of the system can be set up, even during the run. This brings several advantages over conventional methods. The principles of the separation can be easily changed, permitting selective pre-concentration (trapping) of minor components by processing large amounts of a sample to be preformed, effective isotachophoresis or IEF pre-separation and final electrophoretic analysis in one run. Advantages of these combinations are discussed together with the right choice of the working electrolyte. A 1000-fold increase in amount of substance in a column can be achieved for both isotachophoresis and capillary zone electrophoresis combined with CAF-IEF pre-concentration at reasonable working conditions. It enables a limit of detection at the nmol/l level with a concentration factor of about 10(7) to be reached.     

Proton scattering from unstable nuclei

Recent improvements in the intensities and optical qualities of radioactive beams have made possible the study of elastic and inelastic proton scattering on unstable nuclei. The design and performances of an innovative silicon strip detector array devoted to such experiments are described. The quality of the data obtained are illustrated with recent results obtained at the GANIL facility for unstable oxygen, sulfur and argon isotopes. Methods to analyse the data using phenomenological and microscopic optical model potentials are discussed.     

From α‐carbamoyl‐α‐cyano­oxiranes to 3‐halogenopyruv­amides

The crystal structures of the first stable α‐diol from the α‐halogenopyruv­amide series, 3‐chloro‐2,2‐di­hydroxy‐3‐phenyl­propan­amide, C₉H₁₀­ClNO₃, and three products [3‐(4‐chloro­phenyl)‐2‐cyano‐2,3‐epoxy­propan­amide, C₁₀H₇­ClN₂O₂, 3‐bromo‐2‐cyano‐2‐hydroxy‐3‐p‐tolyl­propan­amide, C₁₁H₁₁Br­N₂O₂, 3‐bromo‐2‐oxo‐3‐p‐tolyl­propan­amide, C₁₀H₁₀­BrNO₂] obtained during the systematic synthesis of α‐halogenopyruv­amides are reported. The crystal structures are dominated by hydrogen bonds involving an amide group. The stability of the geminal diol could be ascribed to hydrogen bonds which involve both hydroxyl groups.     

Origin of the Rate Acceleration in the C−C Reductive Elimination from Pt(IV)-complex in a [Ga4L6]12− Supramolecular Metallocage

The reductive elimination on [(Me₃P)₂Pt(MeOH)(CH₃)₃]⁺, 2P , complex performed in MeOH solution and inside a [Ga₄L₆]¹²⁻ metallocage are computationally analysed by mean of QM and MD simulations and compared with the mechanism of gold parent systems previously reported [Et₃PAu(MeOH)(CH₃)₂]⁺, 2Au . The comparative analysis between the encapsulated Au(III) and Pt(IV)-counterparts shows that there are no additional solvent MeOH molecules inside the cavity of the metallocage for both systems. The Gibbs energy barriers for the 2P reductive elimination calculated at DFT level are in good agreement with the experimental values for both environments. The effect of microsolvation and encapsulation on the rate acceleration are evaluated and shows that the latter is far more relevant, conversely to 2Au . Energy decomposition analysis indicates that the encapsulation is the main responsible for most of the energy barrier reduction. Microsolvation and encapsulation effects are not equally contributing for both metal systems and consequently, the reasons of the rate acceleration are not the same for both metallic systems despite the similarity between them.     

Assessing protein–ligand docking for the binding of organometallic compounds to proteins

Organometallic compounds are increasingly used as molecular scaffolds in drug development projects; their structural and electronic properties offering novel opportunities in protein–ligand complementarities. Interestingly, while protein–ligand dockings have long become a spearhead in computer assisted drug design, no benchmarking nor optimization have been done for their use with organometallic compounds. Pursuing our efforts to model metal mediated recognition processes, we herein present a systematic study of the capabilities of the program GOLD to predict the interactions of protein with organometallic compounds. The study focuses on inert systems for which no alteration of the first coordination sphere of the metal occurs upon binding. Several scaffolds are used as test systems with different docking schemes and scoring functions. We conclude that ChemScore is the most robust scoring function with ASP and ChemPLP providing with good results too and GoldScore slightly underperforming. This study shows that current state‐of‐the‐art protein‐ligand docking techniques are reliable for the docking of inert organometallic compounds binding to protein. © 2013 Wiley Periodicals, Inc.