Micellar electrokinetic chromatographic and capillary zone electrophoretic methods for screening urinary biomarkers of human disorders: a critical review of the state-of-the-art

Human urine plays a central role in clinical diagnostic being one of the most-frequently used body fluid for detection of biological markers. Samples from patients with different diseases display patterns of biomarkers that differ significantly from those obtained from healthy subjects. The availability of fast, reproducible, and easy-to-apply analytical techniques that would allow identification of a large number of these analytes is thus highly desiderable since they may provide detailed information about the progression of a pathological process. From among the variety of methods so far applied for the determination of urinary metabolites, capillary electrophoresis, both in the capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) modes, represents a robust and reliable analytical tool widely used in this area. The aim of the present article is to focus the interest of the reader on recent applications of MEKC and CZE in the field of urinary biomarkers and to discuss advantages and/or limitations of each mode.     

Enantioselective conjugate addition of phenylboronic acid to enones catalysed by a chiral tropos/atropos rhodium complex at the coalescence temperature

A highly enantioselective rhodium-catalysed conjugate addition of phenylboronic acid to cyclic enones has been achieved using a dynamic library of chiral phosphorus ligands; the tropos/atropos nature of the ligands in the rhodium complex has been characterised via 31P-NMR.     

Isolated single-molecule magnets on native gold

The incorporation of thioether groups in the structure of a Mn12 single-molecule magnet, [Mn12(O12)(L)16(H2O)4] with L = 4-(methylthio)benzoate, is a successful route to the deposition of well-separated clusters on native gold surfaces and to the addressing of individual molecules by scanning tunnelling microscopy.     

First and second order error estimates for the Upwind Source at Interface method

The Upwind Source at Interface (U.S.I.) method for hyperbolic conservation laws with source term introduced by Perthame and Simeoni is essentially first order accurate. Under appropriate hypotheses of consistency on the finite volume discretization of the source term, we prove -error estimates, , in the case of a uniform spatial mesh, for which an optimal result can be obtained. We thus conclude that the same convergence rates hold as for the corresponding homogeneous problem. To improve the numerical accuracy, we develop two different approaches of dealing with the source term and we discuss the question of deriving second order error estimates. Numerical evidence shows that those techniques produce high resolution schemes compatible with the U.S.I. method.

     

Concise synthesis of all stereoisomers of beta-methoxytyrosine and determination of the absolute configuration of the residue in callipeltin A

All stereoisomers of beta-methoxytyrosine (beta-OMeTyr), a stereo-undefined component of callipeltin A, were synthesized from L- and D-tyrosine. The stereochemistry of beta-OMeTyr in callipeltin A was determined to be 2R,3R by an oxidative procedure and Marfey's analysis. [structure: see text]     

Xanthones from calli of Hypericum perforatum subsp. perforatum

Two new xanthone derivatives, 1-hydroxy-5,6,7-trimethoxyxanthone and 3-O-methylpaxanthone were isolated from callus of Hypericum perforatum subsp. perforatum together with the known paxanthone, cadensin G, 1-hydroxy-6,7-dimethoxyxanthone, 1,3,6,7-tetrahydroxyxanthone, and 1,3,5,6-tetrahydroxyxanthone. The structures of the new compounds were established by spectroscopic methods.     

The theory of energy for sub-Laplacians with an application to quasi-continuity

In this paper, we provide a suitable theory for the energy where μ is a Radon measure and Γ is the fundamental solution of a sub-Laplacian on a stratified group As a significant application, we prove the quasi-continuity of superharmonic functions related to . The proofs are elementary and mostly rely on the use of appropriate mean-value formulas and mean-integral operators relevant to the Potential Theory for .     

A Poisson–Jensen Type Representation Formula for Subharmonic Functions on Stratified Lie Groups

The aim of this paper is to prove a representation formula of Poisson–Jensen type on bounded domains for subharmonic functions related to sub-Laplacians _G on stratified Lie groups G. Our result gives a complete answer to a question arisen in Math. Ann. 325 (2003), 97–122, where the additional hypothesis that is regular for the Dirichlet problem related to _G was made: here we treat the case of arbitrary bounded domains , omitting the hypothesis of regularity. In order to prove our representation formula, an ad-hoc theory of polar sets and capacity with respect to _G is also provided. Mathematics Subject Classifications (2000) Primary 31B10, 31B15; Secondary 35J70, 43A80.Chiara Cinti: Investigation supported by University of Bologna. Funds for selected research topics.     

Berry phase in open quantum systems: a quantum Langevin equation approach

The evolution of a two level system with a slowly varying Hamiltonian, modeled as a spin 1/2 in a slowly varying magnetic field, and interacting with a quantum environment, modeled as a bath of harmonic oscillators is analyzed using a quantum Langevin approach. This allows to easily obtain the dissipation time and the correction to the Berry phase in the case of an adiabatic cyclic evolution.