Abstract: A DNA fragment coding for a modified nuclear glucocorticoid receptor, particularly one mutated in the region coding for the ligand binding domain, so that receptor activity is more strongly inducible by a synthetic glucocorticoid ligand than by a natural glucocorticoid ligand, is disclosed. A recombination system inducible in mammals by means of a fusion protein produced between a recombinase and the binding domain of the ligand derived from the modified glucocorticoid receptor of which the activity is more strongly inducible by synthetic glucocorticoids than by natural glucocorticoids, is also disclosed.

Abstract: A process for shaping penetrating projectiles useful in the manufacture of military ammunition, comprising: preparing an alloy of tungsten, nickel, iron and copper by powder metallurgy, compacting the alloy mass into a rough shaped blank having an axis of revolution, sintering the rough shaped blanks thereby producing a blank having a density of at least 17,000 kg/m.sup.3, and work-hardening the sintered blank at a temperature ranging from ambient temperature to 500.degree. C., thereby producing a blank having a variable degree of reduction in section in a direction parallel to the axis of the blank.

Abstract: The invention relates to a method for the selective separation of a given protein substance having an affinity for a ligand from other substances some of them having the same affinity for the ligand but also having a high molecular weight, higher than that of said protein substance, said substances being in solution.The method consists of filtering said substances on a gel which excludes said high molecular weight substances, said gel being coupled with a ligand for which said protein substance has affinity.The method may be applied to enzymatic and especially to immunoenzymatic assays.