Joséphine Ruta

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This article concentrates on analysis of subtle ECG signal features associated with characteristic temporal variations in the repolarization phase of cardiac electrical activation (i.e., variations that are embedded within the T-wave). These variations are termed T-wave alternans (TWA) to connote larger similarity between T-wave shapes in every other beat(More)
Recent developments in chromatographic supports and instrumentation for liquid chromatography (LC) are enabling rapid and highly efficient separations. Various analytical strategies have been proposed, for example the use of silica-based monolithic supports, elevated mobile phase temperatures, and columns packed with sub-3 microm superficially porous(More)
The commercial C18 columns packed with sub-3 μm shell particles were tested and compared to a reference UHPLC column, in terms of kinetic performance as well as selectivity, retention capability, peak shape and loading capacity. For this purpose, a set of pharmaceutically relevant molecules was selected, including acidic, neutral and basic drugs. Regarding(More)
In this paper, we report a new anti-amino acid aptamer chiral stationary phase (CSP). The enantiomers of histidine were separated using an immobilized histidine-specific L-RNA aptamer (40-mer) and an aqueous buffer as mobile phase. The effects of the variation of different operating parameters, including the mobile phase pH and the MgCl2 concentration as(More)
In this paper, a new aptamer-based capillary electrophoresis (CE) method, which was able to separate the enantiomers of an anionic target (adenosine monophosphate, AMP) displaying the same electrophoretic mobility as that of the oligonucleotidic chiral selector, is reported. The design of the aptamer-modified micellar electrokinetic chromatography (MEKC)(More)
In this paper, we describe an aptamer-based competitive affinity CE (ACE) assay involving (i) the pre-incubation of the target (D-arginine) and the specific ligand (anti-D-arginine-L-RNA aptamer) before (ii) the competition with the labeled target (dansylated D-arginine) through an on-capillary mixing strategy. The effects of some critical operating(More)
The objective of this study was to evaluate various chromatographic approaches for peptide analysis. Initially, the ultra-HPLC (UHPLC) strategy, which consists of using columns packed with sub-2 microm particles at a maximal pressure of 1000 bar, was tested. To limit the backpressure generated by small particles, columns packed with superficially porous(More)
The aim of this study was to evaluate the importance of sample diluents to improve peak shapes in hydrophilic interaction liquid chromatography (HILIC), using low molecular weight (<1000 Da) analytes as well as peptides (with MW ranging between 1000 and 6000 Da) as model compounds. Various solvents were tested including water, acetonitrile, methanol,(More)
In this paper, we report the chiral resolution of arginine using an anti-arginine l-RNA aptamer chiral selector in partial-filling CE. The effects of the capillary temperature, sample load, and aptamer plug length on the enantiomeric separation were assessed. Very high chiral resolving capability was observed at low or moderate capillary temperatures (the(More)
In this work, a target-specific aptamer chiral stationary phase (CSP) based on the oligonucleotidic selector binding to silica particles through a covalent linkage was developed. An anti-D-adenosine aptamer was coupled, using an in-situ method, by way of an amide bond to macroporous carboxylic acid based silica. Frontal chromatography analysis was performed(More)