Biomedical subjects

G Turri

Publications and source records attributed to G Turri.

7 recordsLinked to original sources

PubMed2004

Photoexcitation of He- hollow-ion resonances: observation of the 2s2p2 4P state.

Highly correlated states are studied in He-, a fundamental 3-electron system and prototypical negative ion. The 2s2p(2) 4P state is observed for the first time. This state is detected in a resonant simultaneous double-Auger decay of unprecedented strength. In addition, the first measurements of photodetachment cross sections, positions, widths, and shapes of triply excited resonances in He- are reported. These measurements provide a sensitive test for several sophisticated ab initio calculations, and indicate differences in the position and shape of some structures.

Journal Article↗

PubMed2004

Probing the molecular environment using spin-resolved photoelectron spectroscopy.

Angle- and spin-resolved photoelectron spectroscopy with linearly and circularly polarized synchrotron radiation were used to study the electronic structure of model triatomic molecules, hydrogen sulfide, and carbonyl sulfide. The spin-polarization measurements of the molecular field split components of the S 2p photolines revealed a strong effect of the different molecular environments. The validity of simple atomic models to explain the results is discussed.

Journal Article↗

PubMed2002

O 1s --> sigma* resonance in O2: inadequacy of only two exchange-split components.

The O 1s-->sigma* transition below the O K-edge in O2 has been investigated by absorption, constant ionic state (CIS) experiments, and extensive configuration interaction calculations. CIS scans of the three lowest-lying final states reached in resonant Auger decay provide a wealth of information on energy range, symmetry, and spin multiplicity of the intermediate states with sigma* character. We conclude that the identification of only two exchange-split components is inadequate because a complex manifold of states with sigma* character exists with no unique energy difference between related states.

Journal Article↗

PubMed2002

K-shell photodetachment of He- : experiment and theory.

High-resolution K-shell photodetachment measurements of He- giving rise to He+ ions have been performed using a merged synchrotron vacuum ultraviolet photon-ion beam technique. The measurements on this fundamental negative ion display dramatic structure differing substantially, qualitatively and quantitatively, from the corresponding process in neutral atoms and positive ions, owing to the dominance of correlation in both initial and final states of He-. In addition, this experimental investigation provides an unambiguous test of two independent theoretical calculations that report serious discrepancies and shows excellent agreement with one of them.

Journal Article↗

PubMed2001

K-shell photodetachment of Li(-): experiment and theory.

An experimental K-shell photodetachment study of Li(-) giving rise to doubly photoionized Li(+) ions has been carried out at the Advanced Light Source, using a collinear photon-ion beam apparatus. The experiment reveals dramatic structure, differing substantially both qualitatively and quantitatively from the corresponding processes above the 1s ionization threshold in Li and Li(+), as predicted by our enhanced R-matrix calculation. The experimental/theoretical comparison shows good agreement over some of the photon energy range, and also reveals some puzzling discrepancies.

Journal Article↗

PubMed2001

Experimental observation of post-collision interaction and interference effects in resonant double photoionization processes.

The combined effects of post-collision interaction in the final state and interference due to the indistinguishability of the two electrons have been studied in a selected case of resonant double photoionization of neon. In our coincidence experiments, the photo- and Auger-electron pair was measured when the two electrons have nearly equal energy and are ejected at small mutual angle. The obtained energy distributions exhibit a strong interplay of post-collision interaction and interference effects, in agreement with the theoretical prediction of Sheinerman and Schmidt [J. Phys. B 30, 1677 (1997)] made on beryllium.

Journal Article↗

PubMedDate not supplied

[Paroxysmal tachycardia in children: analysis of two clinical cases].

Two cases of paroxysmal supraventricular tachycardia in children are reported. Associated congenital heart disease were excluded by color-doppler echocardiogram. Electrocardiogram, holter monitoring and transesophageal study (in one case) suggested associated Wolf-Parkinson-White syndrome. The former case was successfully treated with digitalis, the latter, diagnosed "at risk" by transesophageal recording, was long term treated with propafenone. Clinical evaluation at follow-up confirmed the efficacy of the therapy.

Child↗