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Atomic nuclei have a shell structure in which nuclei with 'magic numbers' of neutrons and protons are analogous to the noble gases in atomic physics. Only ten nuclei with the standard magic numbers of both neutrons and protons have so far been observed. The nuclear shell model is founded on the precept that neutrons and protons can move as independent particles in orbitals with discrete quantum numbers, subject to a mean field generated by all the other nucleons. Knowledge of the properties of single-particle states outside nuclear shell closures in exotic nuclei is important for a fundamental understanding of nuclear structure and nucleosynthesis (for example the r-process, which is responsible for the production of about half of the heavy elements). However, as a result of their short lifetimes, there is a paucity of knowledge about the nature of single-particle states outside exotic doubly magic nuclei. Here we measure the single-particle character of the levels in (133)Sn that lie outside the double shell closure present at the short-lived nucleus (132)Sn. We use an inverse kinematics technique that involves the transfer of a single nucleon to the nucleus. The purity of the measured single-particle states clearly illustrates the magic nature of (132)Sn.

The 10.15 MeV resonance in 10Be has been probed via resonant 6He+4He elastic scattering. It is demonstrated that it is the Jpi=4+ member of a rotational band built on the 6.18 MeV 0+ state. A Gammaalpha of 0.10-0.13 MeV and Gammaalpha/Gamma=0.35-0.46 were deduced. The corresponding reduced alpha width, gamma2alpha, indicates one of the largest alpha-cluster spectroscopic factors known. The deformation of the band, including the 7.54 MeV, 2+ member, is large (h2/2I=200 keV). Such a deformation and the significant degree of clusterization signals a well-developed alpha:2n:alpha molecular structure.

The effects of transforming growth factor-beta (TGF-beta) and ACTH on growth, as indicated by [3H]thymidine incorporation into DNA, of primary cultures of neocortical cells from the human fetal adrenal gland were studied. TGF-beta inhibited, in a dose- and time-dependent manner, the growth of fetal neocortical cells, and ACTH significantly blunted the inhibitory effects of TGF-beta on growth of these cells. ACTH did not block the inhibitory effects of TGF-beta on growth of fetal adrenal fibroblasts or liver cells; neither ACTH nor TGF-beta had any effect on growth of fetal kidney cells. Thus, it appears that growth regulation of the neocortex may differ strikingly from that of the fetal zone of the human fetal adrenal, in which ACTH and TGF-beta have been reported recently to have additive inhibitory effects on cell proliferation.