Abstract: 2',3'-Dideoxy-4-thio-uridine derivatives represented by a following general formula ##STR1## (wherein R indicates hydrogen or protecting groups such as acetyl group, benzoyl group, trityl groups, etc.), process for their preparation, antivirus agents used them as effective ingredients and therapeutic method and therapeutic drugs for virus diseases are disclosed.

Abstract: It takes high skill to achieve maximum efficiency of construction equipment under the ever changing working conditions. The automatic implement control system helps maximize operator efficiency and convenience by allowing a predetermined angle, lift and/or tilt position of a work implement (40) to be stored in the memory of the controller (3). In operation, the implement (40) may be moved from that stored predetermined position to perform other functions. In an automatic mode, the controller (3) can return the implement (40) to that predetermined position at any time during the work cycle. A valve (15-70) is provided for selectively switching between manual and automatic modes.