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This paper reports a new phenomenon connected with the influence of green light (GL) on biological systems. Our experiments have revealed an antioxidant effect of GL on cells subjected to lethal doses of UV at the cellular level and a protective effect of GL on DNA denatured by UV, coupled with a structural modification of DNA macromolecules under GL irradiation, at the molecular level. Mouse melanocyte cultures are subjected to UV irradiations with L(50) fluxes of 16.0 J m(-2) s(-1). GL is obtained from a strontium aluminate pigment, which emits GL under UV activation. Cells grown in GL, prior to UV irradiation, present a clear surprising protective effect with surviving values close to the controls. A GL antioxidant effect is suggested to be mediated through GL influence on cellular water cluster dynamics. To test this hypothesis, reactive oxygen species (ROS) are determined in cell cultures. The results revealed a decrease of cellular ROS generation in the UV-irradiated samples protected by a previous 24 h of GL irradiation. At the DNA level, the same type of GL protection against UV damage is recorded by gel electrophoresis and by UV spectroscopy of the irradiated DNA molecules. Two physical methods, impedance spectroscopy and chronoamperometry, have revealed at the level of GL-irradiated DNA molecules spectral modifications that correlate with the UV spectroscopy results. The interaction between the chargeless photons and the field of water molecules from the cellular compartments is discussed in relation with the new field of macroscopic quantum coherence phenomena.

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The Fe spin configurations in both the soft-and hard-magnetic phases of nanocomposite Fe/RE 2 Fe 14 B exchange-spring ribbons have been analysed by Mössbauer spectroscopy. New criteria for evaluating the inter-phase exchange-coupling strength are proposed. The coupling strength is discussed in relation to the annealing conditions and the relative content of the soft magnetic phase.Introduction Pinning the magnetic moments of a soft magnetic (SM) phase to the interfacial moments of a hard magnetic (HM) phase, gives rise to exchange-spring magnetic phenomena. The exchangespring concept opens an alternative route towards new high performance permanent magnets [1][2][3]. The exchange coupling depends on the grain size and the volume fraction of the SM phase as well as on the intrinsic coercive force of the HM phase [2,4,5]. Nanocomposite exchange-spring magnets can be obtained by starting from RE-Fe-B (RE=rare earth) amorphous ribbons. Using suitable annealing treatments, the metastable amorphous structure can be stabilised to a nanocomposite system consisting of a RE 2 Fe 14 B hard magnetic phase and a complementary soft magnetic α-Fe phase. The relative content of the two mentioned phases as well as their degree of crystallization may be controlled via the annealing conditions and the starting composition of the amorphous phase.The present work reports on the local magnetic interactions and Fe spin configuration of Fe/RE 2 Fe 14 B nano-composite systems obtained via annealing treatments applied to RE-Fe-B melt-spun amorphous systems with different compositions. The local structure and magnetic interactions have been investigated by Mössbauer spectroscopy and their macroscopic magnetic behaviour by magnetometry.