Abstract: The activity of alkaline phosphatase in aqueous solution, especially in reconstituted serum, is kept constant by adding to the phosphatase-containing solution Mn.sup.2+ or Cd.sup.2+ ions, preferably to an end concentration of 0.05 to 0.5 mMol/liter of Mn.sup.2+ or 0.05 to 0.1 mMol/liter of Cd.sup.2+. Control serums comprising the Mn.sup.2+ and/or Cd.sup.2+ ions in human or animal serum or serum-like compositions are also provided.

Abstract: A process for the manufacture of homopolymers and copolymers of .alpha.-monoolefins of 2 to 6 carbon atoms by polymerizing the monomer or monomers by means of a Ziegler catalyst system comprising (1) a catalyst component containing titanium and (2) a particular compound of aluminum, magnesium or zinc, the atomic ratio of titanium from catalyst component (1) to metal (Me) from catalyst component (2) being from 1 : 0.1 to 1 : 500, wherein the titanium-containing catalyst component (1) employed is the solid-phase product (VI) obtained by (1.1) first bringing into contact (1.1.1) a particular finely divided, porous, inorganic oxidic material (I) and (1.1.2) a particular aluminum compound (II) dissolved in an organic solvent, to form a solid-phase product (III) and (1.2) then bringing into contact (1.2.1) the solid-phase product (III) obtained from stage (1.1) and (1.2.2) a solution (IV) which is obtained on bringing together (IVa) 100 parts by weight of a particular alcohol, (IVb) from 0.

Abstract: A process for the manufacture of homopolymers and copolymers of .alpha.-monoolefins of 2 to 6 carbon atoms by polymerizing the monomer or monomers by means of a Ziegler catalyst system comprising (1) a catalyst component containing titanium and (2) a particular compound of the metals aluminum, magnesium or zinc, the atomic ratio of titanium from catalyst component (1) to metal from catalyst component (2) being from 1:0.1 to 1:500, wherein the titanium-containing catalyst component (1) employed is the solid-phase product (IV) obtained by bringing into contact (1.1) a finely divided, porous, inorganic oxidic material (I) which has the formula SiO.sub.2 . aAl.sub.2 O.sub.3 --, where a is a number from 0 to 2, and (1.2) a solution (II) formed on bringing together (IIa) 100 parts by weight of an alcohol of the general formula Z--OH, where Z is a saturated hydrocarbon radical of 1 to 8 carbon atoms, (IIb) from 0.01 to 6 parts by weight (calculated as titanium) of a titanium trihalide and (IIc) from 0.

Abstract: A process for the manufacture of olefin polymers by polymerizing .alpha.-monoolefins of 2 to 8 carbon atoms by means of a catalyst which is obtained from a silicate carrier (component a), an organo-metallic compound containing alkoxide groups (component b) and a chromium compound (component c), wherein the catalyst employed is obtained by (1) first charging (1.1) a finely divided porous xerogel (component a) of the formula SiO.sub.2 . m Al.sub.2 O.sub.3, where m is a number from 0 to 2, with (1.2) a particular aluminum compound containing alkoxide groups (component b), (2) then charging (2.1) the product obtained from stage (1) with (2.2) a particular chromium compound (component c) by treatment with a solution of the chromium compound, with intimate mixing and evaporation of the solvent and (3) finally heating the product, obtained from stage (2), in an anhydrous stream of gas containing oxygen.

Abstract: A process for the manufacture of olefin polymers by polymerizing .alpha.-monoolefins of 2 to 8 carbon atoms by means of a catalyst which is obtained from a silicon-containing material (component a), an organo-metallic compound containing alkyl groups (component b) and a chromium compound (component c), wherein the catalyst employed is obtained by (1) first bringing into contact (1.1) an alkogel (component a) of the empirical formula SiO.sub.2 .multidot. m Al.sub.2 O.sub.3 .multidot. n ROH, where m is a number from 0 to 2, n is a number such that the content of ROH in the alkogel is from 1 to 85 per cent by weight and R is alkyl of 3 to 8 carbon atoms, and (1.2) an aluminum compound containing certain alkyl groups (component b), with intimate mixing, to form a solid-phase reaction product, (2) then bringing into contact (2.1) the solid-phase reaction product obtained from stage (1) and (2.

Abstract: Triglycerides are determined by enzymatic saponification with lipase in a buffer in the presence of a carboxylesterase and an alkali metal or alkaline earth metal (10-15 carbon atom) alkyl sulfate, in the additional presence of a compound of the general formula RO(CH.sub.2 CH.sub.2).sub.n H, in which R is alkyl or alkenyl containing 14 to 20 carbon atoms and n is a number of from 7 to 20; this determination prevents turbidity and does not disadvantageously influence enzyme activity.

Abstract: .gamma.-Glutamyl-4-nitroanilide compounds of the formula ##STR1## wherein R is a .gamma.-glutamyl radical and X is an acid group, and salts of such compounds, are used to determine .gamma.-glutamyl-transpeptidase by contacting a sample suspected of containing .gamma.-glutamyltranspeptidase with said compound and glycylglycine and determining the liberation of the resulting p-nitro-aniline compound as a measure of the .gamma.-glutamyltranspeptidase activity initially present in the sample.

Abstract: A process for the manufacture of olefin polymers by polymerization of monoolefins using a silicic xerogel/chromium trioxide catalyst obtained by (1) synthesizing a particulate silicic xerogel, (2) doping said xerogel with chromium trioxide or a chromium compound capable of converting to chromium trioxide under the conditions of stage (3) and (3) heating the resulting product in a gas stream containing oxygen. The silicic xerogel/chromium trioxide catalyst used is one which has been obtained by (1) synthesizing the silicic xerogel in the first stage by (1.1) starting with a silicic hydrogel having a relatively high solids content, (1.2) extracting water from said hydrogel by means of an alkanol and/or alkanone until the organic liquid absorbs no further water, (1.3) extracting the organic liquid used in stage (1.

Abstract: This invention relates to a process for the manufacture of olefin polymers by polymerization of monoolefins with the aid of a silicic xerogel/chromium trioxide catalyst obtained by (1) synthesizing a particulate silicic xerogel, (2) doping this xerogel with chromium trioxide or a chromium compound which converts to chromium trioxide under conditions of stage (3) and (3) maintaining the resulting product at an elevated temperature in a water-free oxygen-containing stream of gas. The characteristic feature of the process of the invention is that the silicic xerogel/chromium trioxide catalyst used is one obtained by (1) synthesizing the silicic xerogel in the first stage as follows: (1.1) taking an aqueous solution of a sodium silicate, (1.2) substituting substantially all of the sodium ions contained in said solution by hydrogen ions by means of an ion exchanger, (1.3) introducing a water-soluble aluminum salt into the resulting aqueous silicic acid solution, (1.

Abstract: A process for the manufacture of olefin polymers by polymerization of .alpha.-monoolefins by means of a silicic acid xerogel/chromium trioxide catalyst, which is obtained by a method wherein (1) a finely divided silicic acid xerogel is first manufactured by (1.1) employing a silicic acid hydrogel of relatively high solids content, (1.2) extracting at least 60% of the water contained in the hydrogel from the latter by means of a particular organic liquid, (1.3) drying the gel thus obtained until there is no further loss in weight (xerogel formation) and (1.4) reducing the xerogel thus obtained to particles of diameter from 20 to 2,000 .mu.m,2. this xerogel is then charged with the desired amount of chromium from a solution of chromium trioxide or a solution of a chromium compound which under the conditions of stage (3) is converted to chromium trioxide, with evaporation of the solvent, and3. finally the product thus obtained is heated in an anhydrous stream of gas containing oxygen.

Abstract: Cholesterol oxidase which oxidizes cholesterol with oxygen to give cholestenone and hydrogen peroxide, is prepared by culturing Nocardia erthropolis ATCC 17895, Nocardia erthropolis ATCC 4277, Nocardia formica ATCC 14811 or Proactinomyce erythropolis NCIB 9158 first on a peptone-containing mineral salt medium and thereafter on at least one sterol compound as the sole source of carbon, and then isolating the cholesterol oxidase formed from the cultured micro-organism, wherein said sterol compound is of the formula ##STR1## in which R.sub.1 and R.sub.2 are hydrogen or together represent a double bond,R.sub.3 and R.sub.4 are hydrogen or together represent a double bond, andR.sub.5 is hydrogen or alkyl containing up to 3 carbon atoms.

Abstract: Particulate olefin polymers are prepared by catalytic polymerization of monoolefins in an auxiliary liquid containing the monomers to be polymerized in dissolved form and the particulate polymer product in suspended form. The reaction mixture is recycled in a loop to which the starting materials are fed and from which the particulate polymer formed is removed. The essential features are (a) that a side stream is branched off from the loop, (b) that the side stream is caused to pass through a separating zone in which particulate olefin polymer is separated by centrifugal acceleration at temperatures and pressures in the same range as present in the loop and (c) that the separated particulate olefin polymer is discharged through flashing means.

Abstract: .gamma.-Glutamyl-4-nitroanilide compounds of the formula ##SPC1##Wherein R is a .gamma.-glutamyl radical and X is an acid group, and salts of such compounds, are used to determine .gamma.-glutamyltranspeptidase by contacting a sample suspected of containing .gamma.-glutamyltranspeptidase with said compound and glycyl-glycine and determining the liberation of the resulting p-nitroaniline compound as a measure of the .gamma.-glutamyltranspeptidase activity initially present in the sample.

Abstract: .gamma.-Glutamyl-4-nitroanilide compounds of the formula ##SPC1##Wherein R is a .gamma.-glutamyl radical and X is an acid group, and salts of such compounds, are used to determine .gamma.-glutamyltranspeptidase by contacting a sample suspected of containing .gamma.-glutamyltranspeptidase with said compound and glycylglycine and determining the liberation of the resulting p-nitroaniline compound as a measure of the .gamma.-glutamyltranspeptidase activity initially present in the sample.

Abstract: Enzyme-kinetic determination of the concentration of an enzyme substrate which is acted on during an enzymatic reaction is carried out by adding at least one competitive inhibitor to an enzymatic reaction medium to bring the ratio of the substrate concentration C.sub.3 to the apparent Michaelis constant K'.sub.M to 0.2:1 or less, homogenizing the medium and determining the rate change of the enzymatic reaction at certain intervals of time.