Showing papers on "Silicic acid published in 1970"
TL;DR: Analysis of the monoacylglycerophosphate formed at pH 6.5 suggests that the 1 isomer is the primary product when palmitoyl-CoA is the substrate and that the 2 isomers is the predominant product formed from oleoyl -CoA.
71 citations
TL;DR: A new procedure in which silicic acid column chromatography and fluorometry are used to assay plasma vitamin A is investigated, finding 34 µg of vitamin A per 100 ml of plasma in 778 preschool children.
Abstract: We investigated a new procedure in which silicic acid column chromatography and fluorometry are used to assay plasma vitamin A. Using tritium-labeled vitamin A acetate and vitamin A alcohol as radioactive standards, we identified two fluorescent components in plasma extracts chromatographed on silicic acid columns. One unidentified fluorescent component was eluted first with hexane or petroleum ether. Vitamin A, the second fluorescent peak, was quantitatively eluted with isopropanol. The isopropanol eluates could be immediately assayed fluorometrically without further treatment. The unidentified compound was sensitive to ultraviolet irradiation, which destroyed it slower than vitamin A is destroyed. Values correlated well for plasma vitamin A concentrations, determined by this procedure and by the Neeld and Pearson modification of the Carr-Price colorimetric method (r = 0.871). By our technique, we found 34 µg of vitamin A per 100 ml of plasma in 778 preschool children.
50 citations
TL;DR: The distribution of phospholipids derived from Micrococcus cerificans was determined under a variety of nutritive conditions and the presence of phosphatidyl-N,N-N'-dimethylethanolamine, phosph atidylcholine in trace quantities was demonstrated.
Abstract: The distribution of phospholipids derived from Micrococcus cerificans was determined under a variety of nutritive conditions. Cells were grown with hexadecane, heptadecane, or acetate serving as the sole carbon source. Total lipid was isolated by chloroform-methanol extraction, and the phospholipid fraction was isolated by silicic acid column chromatography. The phospholipids were characterized by silicic acid chromatography, by thin-layer chromatography, and by identification of water-soluble products resulting from acid hydrolysis of purified phospholipids. Major phospholipids characterized were phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Minor phospholipids were phosphatidylglycerol phosphate and phosphatidylserine. Trace amounts of methylated derivatives of phosphatidylethanolamine were determined by incorporation of 14C from 14C-methylmethionine. These experiments demonstrated the presence of phosphatidyl-N-methylethanolamine, phosphatidyl-N,N′-dimethylethanolamine, and phosphatidylcholine in trace quantities. Pulse labeling with 14C-serine demonstrated the direct incorporation of serine into phosphatidylserine followed by decarboxylation to phosphatidylethanolamine.
47 citations
Patent•
15 Dec 1970
TL;DR: Porous silicic acid has a specific surface of about 50 to 1000 m 2 /g and having an anion content below the chemically determinable limit of detection is made by hydrolyzing methyl or ethyl silicate or polymethyl or polyethyl silicate with about 70 to 120% of the stoichiometric amount of water with moderate stirring as discussed by the authors.
Abstract: Porous silicic acid having a specific surface of about 50 to 1000 m 2 /g and having an anion content below the chemically determinable limit of detection is made by hydrolyzing methyl or ethyl silicate or polymethyl or polyethyl silicate with about 70 to 120% of the stoichiometric amount of water with moderate stirring. Hydrolysis activators such as acids or bases may be present as well as alcoholates of oxides of transition metals which then appear in the end product. Alcohol may also be present to facilitate hydrolysis. The products are characterized by marked purity and their specific surface can be closely and reproducibly controlled.
44 citations
34 citations
TL;DR: Investigations of the phase behaviour on freezing and subsequent melting and of other properties indicate that anomalous water is a solution containing a fixed amount of relatively involatile material in normal water.
Abstract: Investigations of the phase behaviour on freezing and subsequent melting and of other properties indicate that anomalous water is a solution containing a fixed amount of relatively involatile material in normal water. There seems to be no need to postulate the existence of a new polymer of water in such solutions. If only water and silica are present, the properties are consistent with those of a silicic acid gel.
28 citations
26 citations
TL;DR: In this paper, the growth of silicic acid in this hydrosol was found to be linear, and the reasons for hydrogen bonding were given, and it was shown that most of the silanol condensation must occur during the drying of this type of silica gel.
23 citations
TL;DR: Results could be interpreted on the hypothesis that the polymers form an adsorbed layer on the quartz surface, but it is difficult to apply this explanation to two polymers which are inactive when used to pretreat the macrophages but are active when adsorbing on quartz.
Abstract: 1. Poly(2-vinylpyridine 1-oxide) counteracts the pathogenic effects normally produced when quartz is injected into or inhaled by animals and the cytotoxic effects when quartz is added to macrophage cultures. The protective action of this polymer has been attributed variously to the formation of an adsorbed layer on the quartz particles, complex formation with monosilicic acid produced by the dissolution of quartz, and strengthening of the membranes or microstructures of the cells.
2. Stereoregular forms of poly(2-vinylpyridine 1-oxide), some alkyl derivatives of poly(2-vinylpyridine 1-oxide), poly(3-vinylpyridine 1-oxide) and poly(4-vinylpyridine 1-oxide), a copolymer of 2-vinylpyridine 1-oxide and 2-n-propenylpyridine 1-oxide, some poly(1-methyl-2-vinylpyridinium) quaternary salts, and poly(1-methoxy-2-vinylpyridinium iodide), which had previously been synthesized and studied with respect to their viscosities and interaction with silicic acid, were tested for their ability to counteract the cytotoxic effects of quartz in macrophage cultures. The tests were effected both by pretreating the quartz with polymers, and by pretreating the cells.
3. Every polymer proved active in one or other of these conditions, but several were active in one test but inactive in the other. Some polymer quaternary salts, which do not contain the N-oxide group, were found to be active. A remarkable difference in activity was found between the two stereoregular forms of poly(2-vinylpyridine 1-oxide). Pretreatment of the quartz with some of the polymers increased its cytotoxicity significantly.
4. Most of the results could be interpreted on the hypothesis that the polymers form an adsorbed layer on the quartz surface, but it is difficult to apply this explanation to two polymers which are inactive when used to pretreat the macrophages but are active when adsorbed on quartz.
23 citations
Patent•
07 Oct 1970
TL;DR: The authors used colloidal silicic acid for elution of the adsorbed lipoproteins, the latter being suitable for use as a biochemical or immunochemical reagent.
Abstract: Preparation of lipoprotein-free, stable and sterile serum by intimately admixing blood serum or plasma with 250 to 500 mg. colloidal silicic acid per gram of total protein and following removal of the silicic acid subjecting the serum or plasma to irradiation with ultraviolet light and sterile filtration. The separated colloidal silicic acid can be treated for elution of the adsorbed lipoproteins, the latter being suitable for use as a biochemical or immunochemical reagent.
21 citations
Patent•
24 Sep 1970
TL;DR: A highly dispersed homogeneous mixture of activated carbon black and activated silicic acid is formed by subjecting gaseous silicon monoxide or a mixture thereof with a Gaseous metal oxide to the action of a gases oxidizing agent and passing substantially simultaneously a material that forms carbon black upon decomposition into the oxidizing zone or into the stream of gas right above the oxidising zone.
Abstract: A highly dispersed homogeneous mixture of activated carbon black and activated silicic acid is formed by subjecting gaseous silicon monoxide or a mixture thereof with a gaseous metal oxide to the action of a gaseous oxidizing agent and passing substantially simultaneously a material that forms carbon black upon decomposition into the oxidizing zone or into the stream of gas right above the oxidizing zone.
TL;DR: The methyl-deficient and normal methylated tRNAPhe species, found in unfractionated methionine-starved tRNA, were separated and extensively purified employing chromatography on reversed-phase columns, benzoylated DEAE-cellulose and methylated albumin silicic acid columns.
Patent•
17 Apr 1970
TL;DR: An ester condensation product of a perfluoro-tertiary-alkyl alcohol is an organic acid of not more than 18 carbon atoms with at most double bond unsaturation.
Abstract: An ester condensation product of (1) a perfluoro-tertiary-alkyl alcohol in which the perfluoro-alkyl group has not more than 20 carbon atoms, is directly bonded to the alcoholic hydroxyl radical, and has at least one perfluoro-methyl group bonded to the tertiary carbon atom, and (2) an organic acid of not more than 18 carbon atoms with at most double bond unsaturation and selected from the group consisting of a hydrocarbon carboxylic acid, a hydrocarbon sulphonic acid, a hydrocarbon phosphonic acid, a hydrocarbon silicic acid or cyanuric acid, or a halogen substituted counterpart thereof. Illustrative uses of these esters include inert heat exchange fluids, as polymerizable monomers, textile treatment, surface active agents, and the like.
TL;DR: The separation of organic acids and their elution from silicic acid columns and their quantitative measurement by color change of buffered indicator, a technique mechanized by Kesner and Muntwyler, are applicable to the study of biological materials.
Abstract: The separation of organic acids and their elution from silicic acid columns and their quantitative measurement by color change of buffered indicator, a technique mechanized by Kesner and Muntwyler, are applicable to the study of biological materials. As little as 25 µg of acid can be measured. Elution times and color yield in terms of peak areas obtained with the commercial apparatus are given for 25 organic acids. Blood, plasma, red cells, and spinal fluid have been analyzed; specimens were either untreated or extracted with ether. The most abundant acids detected were propionic, lactic, hippuric, and acetic. Methylmalonate was measured in body fluids and blood cells of patients with methylmalonic acidemia and pernicious anemia. Concentrations of organic acids in blood and spinal fluid are given.
Patent•
05 Aug 1970
TL;DR: In this paper, a mixture of trivalent metal salts and bivalent metal salts are used to form metallic oxide coatings on the surface of the sol particles, and the sols as a result are rendered more stable, as indicated by the fact that the viscosity remains constant and the tendency to gel is eliminated.
Abstract: Silicic acid sols are treated with a mixture of trivalent metal salts and bivalent metal salts which react to form metallic oxide coatings on the surface of the sol particles. The sols as a result are rendered more stable, as indicated by the fact that the viscosity of said sols remains constant and the tendency to gel is eliminated. The sols can be dried to give a finely divided product.
TL;DR: In this paper, a procedure permitting the synthesis of both optical isomers as well as the racemic form of saturated or unsaturated phosphotidic acids is reported, which is obtainable by treating the pyridinium salts of L-, D-, or DL-dihydroxypropylphosphonic acid for 24 h at 80° with a mixture of the anhydride and the tetraethylammonium salt of the fatty acid to be introduced, and separating the reaction products by column chromatography on silicic acid.
Abstract: A procedure permitting the synthesis of both optical isomers as well as the racemic form of saturated or unsaturated phosphotidic acids is reported. The phosphotidic acids are obtainable by treating the pyridinium salts of L-, D-, or DL-dihydroxypropylphosphonic acid for 24 h at 80° with a mixture of the anhydride and the tetraethylammonium salt of the fatty acid to be introduced, and separating the reaction products by column chromatography on silicic acid. The preparation of the dipalmitoyl and distearoyl L-dihydroxypropylphosphonic acids is described.
TL;DR: The synthesis of radioactive androsta-4,16-dien-3-one from both 4-[14C]- and 7α-[3 H]-testosterone has been achieved using modifications of a method due to Henbest.
Abstract: The synthesis of radioactive androsta-4,16-dien-3-one from both 4-[14C]- and 7α-[3 H]-testosterone has been achieved using modifications of a method due to Henbest. Contrarily to this earlier report, yields of purified androstadienone were approximately 6%. Other compounds, which may be ring D isomers, have been separated by column chromatography on silicic acid impregnated with silver nitrate. Labelled 17-epitestosterone acetate is also formed in this reaction, and may be readily isolated.
Patent•
16 Feb 1970
TL;DR: In this paper, a procedure for preparing ZIRCONIUM OXIDE by fusing a Zirconium SILICEOUS ORE with an ALKALI METAL CARBONATE or HYDROZIDE is described.
Abstract: A PROCESS IS PROVIDED FOR PREPARING ZIRCONIUM SULFATES BY FUSING A ZIRCONIUM SILICEOUS ORE, SUCH AS ZIRCON SAND, WITH AN ALKALI METAL CARBONATE OR HYDROZIDE TO FORM AN ALKALI METAL ZIRCONYLOSILICATE, AND/OR ALKALI METAL ZIRCONATE, AND SILICATE, WHICH IS DISSOLVED IN AQUEOUS HYDROCHLORIC ACID TO FORM A CLEAR SOLUTION OF ZIRCONYL CHLORIDE AND SILICIC ACID. AN AQUEOUS SULFATE SOLUTION IS ADDED, AND THE MIXTURE HEATED TO RPECIPITATE A ZIRCONIUM SULFATE. THIS CAN BE CALCINED TO FORM ZIRCONIUM OXIDE. IF FLUORIDE IS ADDED WITH THE SULFATE SOLUTION, A SERIES OF BASIC AND ACIDIC ZIRCONIUM FLUOSULFATES CAN BE OBTAINED USEFUL AS A GLASS POLISHING ADDITIVE. THE ZIRCONIUM FLUOSULFATES CAN ALSO BE CALCINED, TO FORM A VERY PURE ZIRCONIUM OXIDE. A PROCESS ALSO IS PROVIDED FOR PREPARING A ZIRCONIUM OXIDE HAVING A VERY LOW PROPORTION OF SILICA, BY CALCINING A ZIRCONIUM COMPOUND COMPRISING SILICA IN THE PRESENCE OF FLUORINE OR A FLUORIDE.
TL;DR: The results suggest that tubular regulation of silicic acid excretion was absent, and diet affected siliic acid clearance only to the extent that it altered the glomerular filtration rate.
Patent•
28 Sep 1970
TL;DR: In this paper, the authors describe a process for the production of a perflusor oalkylsulfonic ACID ARYL ESTER, which is capable of handling up to 12 CARBON atoms, with an ARYL esterer of a SILICIC ACID at a temperature of about 20 to 300 *C.
Abstract: A PROCESS FOR THE PRODUCTION OF A PERFLUOROALKYLSULFONIC ACID ARYL ESTER COMPRISING REACTING A PERFLUOROALKYLSULFONYL FLUORIDE, WHEREIN THE ALKYL GROUP HAS UP TO ABOUT 12 CARBON ATOMS, WITH AN ARYL ESTER OF A SILICIC ACID AT A TEMPERATURE OF ABOUT 20 TO 300*C. IN THE PRESENCE OF A CATALYST. THE AMINOSUBSTITUTED-ARYL ESTERS ARE NEW COMPOUNDS ESPECIALLY USEFUL AS SURFACTANTS, TEXTILE-IMPREGNATING AGENTS, FOAM STABILIZERS, INSECTICIDES AND HERBICIDES, AND ARE ALSO CLAIMED.
TL;DR: A standardized technique for preparation of an efficient and reproducible partition column for the separation of steroid mixtures on one of the commercially available silicic acids is described.
TL;DR: A gas-chromatographic method with temperature programming has been adapted for determining vitamin D in fortified non-fat dried milk by using an acetone-ethanol mixture for protein precipitation and ascorbic acid as an anti-oxidant.
Abstract: A gas-chromatographic method with temperature programming has been adapted for determining vitamin D in fortified non-fat dried milk by using an acetone-ethanol mixture for protein precipitation and ascorbic acid as an anti-oxidant, followed by extraction with chloroform, with a butylated hydroxyanisole-2,6-di-t-butyl-p-cresol mixture as the second anti-oxidant.Sample purification is accomplished by using multi-bore silicic acid column chromatography with gradient elution, followed by antimony trichloride treatment and 2-stage silicic acid micro-column chromatography.Vitamins D2 and D3 are differentiated and determined by gas-liquid chromatography, with one vitamin as internal standard for the other. An over-all average recovery of 104 per cent. of vitamin D2 was obtained when vitamin D2 was used as the internal standard on samples fortified at levels of 10 to 50 µg per 100 g of non-fat dried milk. Approximate total analysis time was 7 hours.
Patent•
28 Jan 1970
TL;DR: In this paper, the authors describe a coating of a rutile pigment with 0.5-25% amorphous dense SiO2 and then with 0A5- 25% Al2O3, based on the weight of the TiO2.
Abstract: 1,179,171. Coated TiO2. E. I. DU PONT DE NEMOURS & CO. 6 Jan., 1967 [7 Jan., 1966], No. 858/67. Heading C1A. TiO2 pigment is coated first with 0A5-25% amorphous dense SiO2, and then with 0A5- 25% Al2O3, based on the weight of the TiO2. The TiO2 is rutile, 0A1-1A in diameter, obtained by TiCl4 oxidation, and may contain 0A3-3% Al2O3 by co-oxidation with AlCl3. It is dispersed in water and mixed with active SiO2 at a pH above 8, a temperature of 40‹ C. to b.pt., and an alkali metal ion concentration below IN. The active SiO2 is preferably formed in situ by acidification of Na or K silicate, or may be silicic acid obtained by cation exchange of Na silicate. The pH is then lowered to 7 or below with acid to precipitate SiO2. The acid may be H2SO4, HCl, HNO3, HAc, H3PO4, NaHSO4, acid phosphates, or carbonic acid, and is preferably added in a plurality of streams. The slurry is then mixed with an Al compound, e.g. Al2(SO4)3, AlCl3, or Na aluminate +H2SO4, while maintaining a pH<7, AND HYDROUS AL2O3 is precipitated by adjusting the pH to 7-8 with base, e.g. NaOH solution. The pigment is filtered, washed, dried at below 450‹ C., e.g. at 125-150‹ C., preferably by spray-drying with air or steam, and ground, e.g. in a fluid energy mill with steam at 250‹ C.
TL;DR: Interaction of ascorbic acid with silicic acid in the solid state was studied using diffuse reflectance spectroscopic techniques and furfural was a major degradation product; whereas in the adsorbed state,furfural could not be detected.
TL;DR: A rapid procedure for the preparation of highly purified transforming Hemophilus influenzae DNA with at the most 3 % residual proteins and with practically no RNA contamination is described.
TL;DR: (l- 14C)-dodecanal was synthesized from (l-14C)- dodecanoic acid and purity was verified by thin layer chromatography and stimulation of light emission catalysed by bacterial luciferase.
Abstract: (l-14C)-dodecanal was synthesized from (l-14C)-dodecanoic acid. The two-step synthesis beginning with 0.9 mg of the acid resulted in an overall yield of 42 % after purification. The final product was separated from the starting material and side products by silicic acid column chromatography. Purity was verified by thin layer chromatography and stimulation of light emission catalysed by bacterial luciferase.
Patent•
01 Sep 1970
TL;DR: In this paper, a cylindrical reactor with a lateral pipe connecting its upper and lower portions is used for hydrogenation in the presence of glacial acetic acid and trichloroacetic acid.
Abstract: 1,249,718. Chloroacetic acid. KNAPSACK A.G. 23 Dec., 1969 [24 Dec., 1968], No. 62583/69. Heading C2C. Monochloroacetic acid containing dichloroacetic acid, acetic acid and, optionally, trichloroacetic acid is purified by passing excess hydrogen into the crude liquid at 60-170‹ C. having suspended therein 0A05 to 15% wt. of a fine particulate catalyst comprising an inert carrier and less than 1% wt. of a metal of Group VIII of the Periodic table. The metal specified is palladium and supports specified are silicic acid and active carbon, an exemplified catalyst having a particle size of 40 to 200 microns. Preferably at least 5 times the theorectical amount of hydrogen is used, and the catalyst-containing feed material is circulated thereby. The feed material may be obtained by the chlorination of glacial acetic acid in the presence of acetic anhydride and acetyl chloride, followed by saponification. Hydrogenation may be effected in a cylindrical reactor having a lateral pipe connecting its upper and lower portions. Such reactors may be used in series.
TL;DR: In this paper, a cyclopropene structure was proved by spectroscopy and chemical methods, and the separable amount of the photoproduct was 9.5%.
Abstract: Methyl sterculate was isolated from an irradiation mixture obtained by photolysis of diazomethane in presence of methyl stearolate by column chromatography on silicic acid. The separable amount of the photoproduct was 9.5%. The presence of the cyclopropene structure was proved by spectroscopy and chemical methods.
Patent•
29 Jun 1970
TL;DR: In this paper, Kombinat et al. presented a method for improving the interfacial adhesion of inorganic fiber materials, especially desized fabrics of glass fibre materials to resins, wherein inorganic fibre materials are treated with a solution of an epoxy silane and, for the production of composite materials, a resin specific coupling agent of the silane type, containing unsaturated radicals, is added to the resin.
Abstract: 1,260,798. Laminates. VEB KOMBINAT TECHNISCHES GLAS ILMENAU. 29 June, 1970, No. 31303/70. Heading B5N. [Also in Division D1] Method for improving the interfacial adhesion of inorganic fibre materials, especially desized fabrics of glass fibre materials to resins, wherein inorganic fibre materials are treated with a solution of an epoxy silane and, for the production of composite materials, a resin specific coupling agent of the silane type, containing unsaturated radicals, is added to the resin. Vinyl or methacrylate silane is used as the silane in the case of the use of unsaturated polyester resins and epoxy-silane is used for epoxide or phenolic resins. The inorganic fibre materials may also be impregnated with a solution comprising an organo-silane, preferably containing unsaturated radicals, and a chromium salt of an organic and/or inorganic acid. To improve the wettability by the resin, the inorganic fibre materials are treated with coupling agents containing polymeric compounds and/or phenol derivatives and/or silicic acid compounds and/or inorganic pigments. It is possible to add, as polymeric compounds, water soluble and/or water dispersible polymers and as phenol derivatives dihydroxy-benzenes, and as silicic acid compounds aqueous dispersions of silicon dioxide and/or silicic acid ester dispersions and/or dispersions of condensed silicic acid esters, and as inorganic pigments titanium dioxide, calcium carbonate and antimony trioxide preferably in dispersed form. For the production of composite materials, the above treated inorganic fibre materials are impregnated with a resin either in pure form or modified with silane. Examples of polymeric compounds are polyvinyl pyrrolidone solutions, epoxide resin dispersions, dispersions of unsaturated polyester resins; examples of phenol derivatives are resorcinol, precondensates or condensates of resorcinol with formaldehyde as solutions or dispersions and examples of resins are thermosetting or thermoplastic resins and silicone resins or elastomers. The fabric of inorganic material is first desized, preferably thermally and then impregnated with mixtures of the described coupling agents and additives, whereupon it is dried and set at an elevated temperature.