Abstract: A sialic acid derivative having an active carbonyl group represented by the formula [I]: ##STR1## wherein R.sup.1 represents hydrogen or acetyl group; R.sup.2 represents hydrogen, a metal or a lower alkyl group; R.sup.3 represents hydrogen, hydroxyl group, or a residue removed hydrogen from an alcohol portion of an active ester; Ac represents acetyl group; and n is 1 to 20, respectively. This sialic acid derivative [I] can be utilized as a starting material for various complex having a sialic acid in the molecule since it has an active carbonyl group in the molecules so that it shows high reactivity.

Abstract: A screw rotor assembly for a screw compressor or the like includes a male screw rotor and a femal screw rotor having rotor teeth each having a profile consisting of a plurality of special curves designed to reduce both the length of the sealing line and the area of the blow hole. The confugurations of the male and female screw rotors reduces the abrasion of the screw rotor assembly as well as the length of the sealing line and the area of the blow hole, so that the performance of the screw rotor assembly is improved. The length of the sealing length and the area of the blow hole in the screw rotor assembly of the present invention are about 10% and about 50%, respectively, of those of the conventional screw rotor assembly.

Abstract: Novel unnatural ceramide related compounds, for instance, (2S, 3S)-2-tetracosanamido-octadecane-1,3-diol are herein provided, which are useful as intermediates in preparing ceramide moieties employed in the preparation of glycolipids and gangliosides known as tumor markers or molecular markers and which are prepared by, for instance, subjecting a chiral compound represented by the following formula: ##STR1## to deacetal treatment.

Abstract: The present invention relates to a new process for preparing 3-O-(sodium(5-acetamide-3,5-dideoxy-alpha-D-glycero-D-galacto-2-noneuro pyranosyl)onate-1,2-di-O-tetradecyl-Sn-glycerol (3) consisting essentially of hydrolyzing a 3-O-(C.sub.1-5 alkyl(5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-di-deoxy-alpha-D-glycero-D-ga lacto-2-noneuropyranosyl)onate)-1,2-di-O-tetradecyl-Sn-glycerol (1) in a single step, in an aqueous lower aliphatic alcohol solution of an alkali metal hydroxide.

Abstract: This invention provides a novel process for preparing a compound represented by the formula ##STR1## In accordance with this invention, the compound is prepared by reacting a compound represented by the formula ##STR2## with glycolic acid in the presence of dicyclohexylcarbodiimide.

Abstract: A novel N-acetylneuraminic acid derivative, represented by the general formula: ##STR1## wherein the R.sup.1 groups are, independently, hydrogen or acetyl; R.sup.2 is a nucleoside residue; and R.sup.3 is carboxyl or methoxycarbonyl.The N-acetylneuraminic acid derivative is useful in inhibiting metastasis of cancer cells. Also provided is a process for the preparation of the derivatives.

Abstract: This invention provides a novel compound having a formula such as ##STR1## This invention also provides a process for preparing such a compound. The novel compound has excellent immunological activity.

Abstract: A screw compressor which a casing defining therein a pair of cylindrical chambers axially intersected, and a pair of male and female screws in an intermeshing relationship. The casing includes an inlet port having a profile composed of an open area fully open to the chambers and the remaining solid area occupied with one portions of shafts of the screws and with one portion of the casing, said profile being equal to a profile of the chambers, such that the fluid can flow freely into the chambers without causing turbulent fluid flow.

Abstract: This invention provides a novel compound having a formula such as ##STR1## This invention also provides a process for preparing such a compound. The novel compound has an excellent immunological activity.

Abstract: A slide valve type screw compressor having a slide valve with a surface of chevron shape in section consisting of a couple of arcuately curved surfaces forming part of the inner wall surfaces of a rotor chamber accommodating a pair of intermeshed male and female screws, the slide valve being slidable in the axial direction of the rotors for communicating the rotor chamber with a suction port through an opening with an adjustably variable area for volumetric control of the compressor, characterized in that the slide valve is retractably protruded into a suction casing at a fore end on the side of the suction port and has the opposite outer corner portions of the curved surfaces cut off at a predetermined angle with the longitudinal axis thereof to provide a substantially triangular section with a forwardly reduced width at the protruded fore end.

Abstract: Novel cephalosporin derivatives are described which have excellent antibiotic activity against pathogenic bacteria belonging to the Pseudomonas, Serratia and Enterobacter. The compounds have general formula ##STR1## in which R is hydrogen, acyloxy, carbamoyloxy, a substituted or unsubstituted pyridinium group or a group -S-Het in which Het represents a substituted or unsubstituted, hetero atom-containing, 5- or 6-membered heterocyclic ring, R' is hydrogen, alkali metal, an organic amine or an ester moiety, R.sub.1 and R.sub.2 are the same or different and are hydrogen or a lower alkyl and B stands for a 1,4-cyclohexadienyl group, a group ##STR2## in which Y is hydrogen, --OH or ##STR3## in which R.sub.5 is an alkyl of 1 to 5 carbon atoms, aryl or alkoxy having 1 to 4 carbon atoms, Z stands for hydrogen or halogen and p is an integer of 1 or 2, a furan group or a thiophene group. Methods of preparation are described.

Abstract: (E)-2-[p-(.beta.-Substituted-vinyl)phenyl]alkanoic acids represented by the formula (I): ##STR1## wherein R.sub.1 and X are as hereinafter defined, having anti-inflammatory, analgesic, antipyretic and platelet aggregation inhibitory activities.