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N Leclercq

Publications and source records attributed to N Leclercq.

5 recordsLinked to original sources
PubMed2002

Nondipolar electron angular distributions from fixed-in-space molecules.

The first indication of nondipole effects in the azimuthal dependence of photoelectron angular distributions emitted from fixed-in-space molecules is demonstrated in N (2). Comparison of the results with angular distributions observed for randomly oriented molecules and theoretical derivations for the nondipole correction first order in photon momentum suggests that higher orders will be needed to describe distributions measured in the molecular frame.

Journal Article↗
PubMed2001

Dynamical angular correlation in molecular Auger decay.

The first measurements of the angular distribution of Auger electrons from fixed-in-space molecules have been performed in the C K-shell ionization region of CO, for both parallel and perpendicular orientations of the molecular axis with respect to the light polarization vector. The angular distributions obtained for the CO(2+)B(1)Sigma Auger final state show dramatic spectral variations, which also depend on the initial ionization channels, Sigma or Pi, and on the ionization photon energy. This dynamical angular correlation process strongly suggests the breakdown of a two-step model in which the Auger decay is treated independently of the initial photoionization process.

Journal Article↗
PubMed1991

Interest of zinc determination in leucocyte fractions for the assessment of marginal zinc status.

In order to test the sensitivity of leucocyte zinc determination in the assessment of zinc status, an isolation procedure of mononuclear (MNC) and polymorphonuclear (PMNC) cell fractions was developed. Zinc concentrations in cells from healthy subjects were (mean +/- SD, in mumol/10(10) cells): 0.81 +/- 0.24 in MNC and 0.55 +/- 0.06 in PMNC. In patients suffering from several diseases known to be associated with a marginal impairment in zinc status (cirrhosis, cancer, obesity, endocrine and rheumatic diseases), these concentrations did not differ from those in controls except in rheumatic patients in whom MNC zinc was increased (1.05 +/- 0.42 mumol/10(10) cells) and correlated with erythrocyte sedimentation rate (r = 0.41, P less than 0.01). This relation was also significant in the whole study population (r = 0.39, P less than 0.01). Leucocyte zinc therefore appears to have a limited value in the assessment of marginally impaired zinc status, except in inflammatory states.

Adult↗
PubMed1991

Factors affecting determinations of manganese in serum by atomic absorption spectrometry.

A method was developed for the routine determination of manganese in serum from healthy human subjects by graphite furnace atomic absorption spectrometry. We controlled the experimental conditions rigorously, from sampling to analysis, to minimize contamination and to conserve diluted samples. We optimized the procedure with two serum Reference Materials, one of which had a manganese concentration very close to what is thought to be the physiological concentration in humans. The best analytical performance was obtained by directly injecting into the furnace serum diluted with an equal volume of a solution containing Triton X-100 and sodium EDTA and calibrating by the standard additions procedure or by a calibration graph constructed in a similar matrix. The Zeeman background correction produced better accuracy and precision than did the classical deuterium correction. Within-run CV for a manganese concentration of 12.7 nmol/L in serum was 7.9%, and between-run precision was 16.1%. The mean (SD) serum manganese concentration in 31 healthy adults was 10.8 (SD 3.0) nmol/L. Sex and age of subjects did not affect concentrations.

Blood Specimen Collection↗