The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.

Positive ion electrospray mass spectra of arsenobetaine, AB, arsenocholine, AK, monomethylarsonic acid, MMA, dimethylarsinic acid, DMA, tetramethylarsonium TMAs, arsenate, AsV, and arsenite, AsIII, have been obtained. When appropriate, negative ion electrospray mass spectra have been performed. In order to clarify fragmentation pathways MS/MS spectra have also been recorded. Positive ion electrospray mass spectra have been found to be more useful for the identification of the organoarsenic compounds AB, AK, MMA, DMA and TMAs, whereas negative ion electrospray mass spectra is more suitable for the identification of the inorganic compounds AsV and AsIII. © 1997 John Wiley & Sons, Ltd.

The evidence that natural and synthetic drugs can affect radiolabeling or bioavailability of radiopharmaceuticals in setting of nuclear medicine clinic is already known. However, this drug interaction with radiopharmaceuticals (DIR) is not completely understood. Several authors have described the effect of drugs on the labeling of blood elements with technetium-99m (99mTc) and on the biodistribution of radiopharmaceuticals. When the DIR is known, if desirable or undesirable, the natural consequence is a correct diagnosis. However, when it is unknown, it is undesirable and the consequences are the possibility of misdiagnosis and/or the repetition of the examination with an increase of radiation dose to the patient. The possible explanation to the appearance of DIR are (a) radiopharmaceutical modification, (b) alteration of the labeling efficiency of the radiopharmaceutical, (c) modification of the target, (d) modification of no target and/or the (e) alteration of the binding of the radiopharmaceutical on the blood proteins. The effect of drugs on the labeling of blood elements with 99mTc might be explained by (i) a direct inhibition (chelating action) of the stannous and pertechnetate ions, (ii) damage induced in the plasma membrane, (iii) competition of the cited ions for the same binding sites, (iv) possible generation of reactive oxygen species that could oxidize the stannous ion and/or (v) direct oxidation of the stannous ion. In conclusion, the development of biological models to study the DIR is highly relevant.

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Neutrino oscillation experiments have proved that neutrinos are massive particles but the assessment of their absolute\ud mass scale is still an outstanding challenge in today particle physics and cosmology. The laboratory experiments dedicated\ud to effective electron-neutrino mass determination are the ones based on the study of single beta decay or electron\ud capture (EC) decay. Exploiting only on energy-momentum conservation, this kinematic measurement is the only one\ud which permits to estimate neutrino masses without theoretical assumptions on neutrino nature and it is truly modelindependent.\ud To date the most competitive isotopes for a calorimetric measurement of the neutrino mass are 187Re and 163Ho. While the first decays beta, the latter decays via electron capture, and both have a Q-value around 2.5 keV.\ud The measurement of 163Ho EC is an appealing alternative to the 187Re beta decay measurement because few nuclei are\ud needed and it is a self-calibrating measurement. In this context the MARE project, based on rhenium thermal detectors\ud has been born.\ud We report here the status of MARE in Milan with Rhenium and the activity concerning the production of radioactive\ud 163Ho isotope in the framework of MARE

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