Structure-property relationships from universal signatures of plasticity in disordered solids.

When deformed beyond their elastic limits, crystalline solids flow plastically via particle rearrangements localized around structural defects. Disordered solids also flow, but without obvious structural defects. We link structure to plasticity in disordered solids via a microscopic structural quantity, "softness," designed by machine learning to be maximally predictive of rearrangements. Experimental results and computations enabled us to measure the spatial correlations and strain response of softness, as well as two measures of plasticity: the size of rearrangements and the yield strain. All four quantities maintained remarkable commonality in their values for disordered packings of objects ranging from atoms to grains, spanning seven orders of magnitude in diameter and 13 orders of magnitude in elastic modulus. These commonalities link the spatial correlations and strain response of softness to rearrangement size and yield strain, respectively.

[Treatment of prolactin-secreting pituitary tumors with bromocriptine].

9 women and 6 men with prolactin-secreting pituitary tumors--prolactinomas (mean age 41 years, range 28-57), were treated conservatively with bromocriptine. The women usually presented with galactorrhea, menstrual disorders and headaches, and the men with headaches, decreased libido or impotence, and visual abnormalities. The symptoms had lasted from several months to 20 years, but were not correlated with tumor size. Between 77-100% of symptoms improved during bromocriptine. Prolactin levels, which correlated with the size of the tumor, averaged 1241 ng/ml before treatment and became normal in 80% of the patients. Tumor size decreased in 58% of those with macroprolactinomas. Lesions of decreased density were found in another 17% of the patients. Side-effects of bromocriptine were minor and disappeared despite continuation of therapy. The results of this series, as well as those of others, indicate that bromocriptine is the treatment of choice for micro- and macroprolactinomas.