Abstract: A surgical instrument (10) for removing a sample (50, 82) from a body of tissue (80) comprises a support structure (30) and a knife (32) arranged to cut into the body of tissue (80). The knife (32) has at least a first blade (36a), a second blade (36b) and a third blade (36c), and each blade has two cutting edges (42a, 44a; 42b, 44b; 42c, 44c) defining an apex. The knife (32) is movable between a first configuration in which the blades (36a, 36b, 36c) are substantially aligned along the longitudinal axis (X) of the support structure (30), and a second configuration in which the blades (36a, 36b, 36c) define the walls of a pyramidal enclosure for containing the sample (50, 82). In one embodiment, the instrument (10) further comprises a biasing member (52a, 52b, 52c) arranged to urge each blade (36a, 36b, 36c) towards the central axis (X) of the support structure (30).

Abstract: The reaction product of (i) an oligomer formed from one monomer or two or more different monomers, the or each monomer being an ethylenically unsaturated compound and said oligomer or each of said monomers being optionally partially or fully esterified, with (ii) a polyalkenyl derivative of an ethylenically unsaturated carboxylic reagent (iii), and (iv) a polyamine containing at least two --NH.sub.2 and/or --NH groups, wherein at least one of the ethylenically unsaturated compounds of the oligomer has a functional group which can react with an amine; and the use of the reaction product for its dispercency and low haze properties in lubricant compositions, fuel compositions and additive concentrates.

Abstract: The invention provides reaction products of:(A) an acylating reagent, with(D) a polyalkenyl derivative of an ethylenically unsaturated carboxylic reagent (C), and(E) a polyamine containing at least two --NH.sub.2 and/or --NH groups, or with(F) the pre-formed product of reagents (D) and (E), wherein the acylating reagent (A) is the reaction product of(B) a C.sub.4 -C.sub.20 polyene or oligomer prepared therefrom, and(C) an ethylenically unsaturated carboxylic reagent; lubricating oil compositions, fuel compositions and additive concentrates containing them; and use of the reaction products as dispersant additives.