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Biomedical subjects

D Tonelli

Publications and source records attributed to D Tonelli.

At least 37 records · Page 2Linked to original sources
PubMed1988

Radioactivity in breast milk and placentas during the year after Chernobyl.

After the April 1986 nuclear reactor accident at Chernobyl in the Union of Soviet Socialist Republics, samples of human placenta and breast milk were tested for 1 year to determine the levels of radioactivity. The radionuclide iodine 131 was never beyond the detection limit of our gamma detector for both matrices. As to cesium isotopes 134 and 137, the highest levels detected in breast milk (6 Bq.L-1) and placenta (15.8 Bq.kg-1) were recorded in March 1987. Study data for breast milk and placenta are in agreement with the values calculated by means of double-compartment food-milk and food-placenta models. With regard to placental content, the cesium contribution to the average dose during the year after the Chernobyl accident was calculated to be 40 to 60 microSv.

Accidents, Occupational↗
PubMed1987

Identification of cosmetic dyes by ion-pair reversed-phase high-performance liquid chromatography.

A method based on ion-pair reversed-phase high-performance liquid chromatography with detection at four wavelengths between 400 and 600 nm is reported for the separation and identification of the most common synthetic colour additives in cosmetic products. All the dyes generally employed in the U.S.A. and almost all those in current use in cosmetics in the European Community have been taken into account. The chromatography was performed on a C8 bonded silica packed column, with a 60-min gradient changing from 10 to 95% acetonitrile in water containing 10(-2) M sodium perchlorate (pH 3.0) as mobile phase (flow-rate 2.5 ml/min). Detection limits are in the range 20-100 ng for all dyes investigated. The method has been applied to the analysis of commercial lipsticks.

Chromatography, High Pressure Liquid↗
PubMed1984

Electrochemical and pulse radiolysis study of misonidazole and its azo and azoxy derivatives.

Pulse radiolysis experiments were carried out on methanolic solutions of misonidazole and its azo and azoxy derivatives in order to obtain the spectra of their radical anions. The rate constants for the reaction of these compounds with es- were 2.5 X 10(10), 2.3 X 10(10) and 1.9 X 10(10) M-1 s-1 respectively. The electrochemical properties of the compounds were studied with the aim of producing their radical anions by electrolysis in aprotic medium (DMF, 0.1 M TEAP ). The potentials at cathodic peaks were -1.05, -1.10 and -1.18 V for misonidazole, azo and azoxy derivatives, respectively. The decay of the radical anion of misonidazole, which produces nitrite ions, was studied in particular, the corresponding rate constant being 2.8 X 10(-4) s-1. The possibility of using electrochemistry in the study of these transient species is discussed.

Electrochemistry↗