Abstract: This invention relates to certain 3-aryl or 3-heteroaryl pyrazoles with 4,5(3,4)-bicyclic ring fusion which are inhibitors of protein kinase activity, of which some are novel compounds, to pharmaceutical compositions containing these pyrazoles and to processes for preparing these pyrazoles.

Abstract: The invention provides compounds of formula I ##STR1## and pharmaceutically acceptable salts thereof; wherein R.sub.50 is hydrogen or C.sub.1-4 alkyl, A.sub.51 is oxygen, sulphur or a group of the formula --NR.sub.52 -- wherein R.sub.52 is hydrogen or C.sub.1-4 alkyl; A.sub.50 comprises i) a mono or bicyclic aromatic ring optionally containing one or more nitrogen, oxygen or sulphur atoms, ii) a cycloalkendiyl group, or iii) an acyclic bridging group having a chain of one, two or three atoms between the cyclobutenedione group and X.sub.50, said chain being a chain of one or two carbon atoms or a chain of one carbon atom and one or more nitrogen, oxygen or sulphur atoms or iv) a bond; X.sub.50 is either a bond or a spacer group providing a chain between A.sub.50 and B.sub.50 of one or two atoms length; B.sub.

Abstract: An elongated rigid bar is arranged to be secured at one of its ends to a power unit and is enclosed through most of its length in a rigid housing. Longitudinal passageways are provided interiorly of the housing for receiving a cross link drive chain trained over a sprocket on the power unit and on a cross shaft supported at a free end of the housing. The cross shaft supports digging units. A ground engaging support wheel is attached to the housing adjacent its free end. The housing has a semi-flexible guard mounted on it adjacent the digging units.