Abstract: An asymmetrical membrane for use in dialysis and ultra-filtration is prepared using a polyester-amide (TATE).sub.n, wherein T represents a radical of terephthalic acid, A represents a radical of hexamethylenediamine, and E represents a radical of hexanediol, in a solvent of formic acid or in a solvent comprising a solution of lithium chloride in dimethylformamide or dimethylacetamide. The polyester-amide (TATE).sub.n is formed into a thin layer and placed into an aqueous coagulation bath to coagulate the resulting membrane. The membrane has a thickness of from 15 to 190 .mu.m, a water permeability of from about 3 up to about 9 liters/m.sup.2 /hour for a .DELTA.P of 300 mm.sub.HG and is permeable for substances having a molecular weight of up to about 17,000.

Abstract: A hollow fibre of polyester-amide, useful in the process of dialysis and in ultra-filtration processes in general, is formed by a polyester-amide with repetitive units (TATE).sub.n (wherein T is the terephthalic acid radical; A is the ethylenediamine radical; and E is the hexanediol radical).Such a fibre is obtained by a process which comprises the following steps, carried out sequentially:preparation of a solution of polyesteramide (TATE).sub.n in a solvent constituted by formic acid at a concentration higher than about 99%, or constituted by a solution of lithium chloride in dimethylformamide or dimethylacetamide;extrusion of said solution through a spinnerette having a cross section of annular shape and coagulation of the fibre in an aqueous coagulation bath, with the possible introduction of an aqueous coagulating liquid to the interior of the annular opening of the spinnerette;washing with water and recovery of the so-obtained hollow fibre.

Abstract: The invention relates to a zirconium phosphate in particles having sizes comprised within the range of from 1 to 100 .mu.m, a lamellar structure with interlayer distance, in the anhydrous state, comprised within the range of from 7.9 to 8.2 .ANG. and a surface area comprised within the range of from 9 to 20 m.sup.2 /g.The method consists in altering the lamellar structure of a zirconium phosphate with layer structure of alpha type by intercalating into it an organic substance containing a proton-acceptor group and water and by a treatment with ultrasounds, in regenerating the hydrogen form of said zirconium phosphate by an acid and in washing the same with diluted acids and/or water.

Abstract: Mixed phosphorous or arsenic salts of tetravalent metals are provided having the general formula M(HAO.sub.4).sub.2-x (HAO.sub.3).sub.x.nH.sub.2 O, where M is Zr, Ti or Hf, A is phosphorus or arsenic, x is between 0.05 and 1.95, and n is 0 to 6. The salts are highly stable and have wide potential application in the fields of ion exchange, catalysis, intercalation of molecules, solid electrolytes, and chromatography. The salts are prepared by reacting a halide, oxyhalide, nitrate, sulphate, phosphate or oxide of the tetravalent metal, preferably in an aqueous medium, with at least two oxygenated acids of phosphorus and/or arsenic.

Abstract: This invention relates to chemical products of general formula ##STR1## wherein R is an amino group, mono or bi-hydroxyalkyl substituted, or a thio group, mono hydroxyalkyl substituted, in which one or more of the available --OH groups have been esterified with acids containing 2 to 18 carbon atoms.It is also described a process for the preparation of said products, which comprises reacting a corresponding starting compound, N or S-hydroxyalkyl substituted, with the chloride or the anhydride of the acid concerned.

Abstract: Hollow chitosan fibres for use in ultrafiltration processes are described, and which can be plasticized by the addition of glycerin such that they contain this latter in a quantity variable between 0.5 and 5% by weight with respect to the polymer. Said fibres are prepared by the wet spinning of acid chitosan solutions, using an alkali solution as the external fibre coagulant and a gaseous phase containing a basic gaseous component as the internal fibre coagulant.

Abstract: A prosthetic polymer material is made non-thrombogenic by immobilizing apyrase on its surface. Immobilization is preferably carried out by hydrolytically activating the surface of a polyamide polymer or a polyethylene terphthalate polymer, and treating the hydrolyzed polymer with a solution of cross-linking agent and a solution of apyrase. The apyrase converts adenosine diphosphate to adenosine monophosphate and adenosine whereby the formation of thrombi is inhibited.

Abstract: Fibres for biological uses can be produced by adding to a spinnable solution of a polymer selected from among many of the most common polymers and copolymers, a substance selected from among anti-platelet aggregation substances, anticoagulants and substances having a similar action. The substances can also be applied as a surface outer layer to articles made with the polymeric substances.

Abstract: Polyamide materials for the construction of protheses and surgical sundries are made biocompatible by inducing a superficial hydrolysis by treating such materials, either raw or in the form of shaped articles, with a normal multiple solution of hydrogen chloride. Thrice normal or fourfold normal solutions are preferred and the treatment time being a function of the temperature. At human body temperature (37.degree. C.) a treatment time from 30 to 60 minutes will do.

Abstract: A method is disclosed for embedding sequestering agents in filamentary structures, the method comprising the steps of preparing an emulsion formed by an aqueous or nearly aqueous solution of the sequestering agent and a solution of the filament-forming polymer in an appropriate solvent, and spinning the emulsion in a coagulation bath.

Abstract: Phenylalanine level in blood or another medium is considerably reduced and can even be annulled by causing blood or the other medium to flow through a mass of porous fibers in which the enzyme phenylalanine ammonia lyase has been occluded: the fibers have been previously made biocompatible, if necessary.

Abstract: Biocompatible articles are obtained by treating a polymeric material with a hydrolyzing agent on its surface and covalently binding thereon a biological agent, such as an anti-platelet-aggregation agent.

Abstract: For effecting enzymic reaction, a reactor is disclosed, in which the flow of the solution to be treated through the catalytic bed material takes place radially. It is preferred to have the catalytic bed in the form of coils of enzyme-occluding fibers. The coils are variously piled up within the reactor. High outputs, low pressure drops and more than satisfactory conversion rates are obtained.

Abstract: Artificial fibres containing antibodies, antigens or antisera are prepared by emulsifying the substances to be incorporated in the interior of the fibres and spinning the emulsion thus obtained through a spinneret immersed in an appropriate coagulation bath, when the coagulation liquor and the solvent(s) have been removed, a fibre is obtained which can be used in many fields wherever it is required to remove antibodies, antigens or antisera from certain substances. The fibres thus obtained could also be used for chromatographical methods of the affinity chromatography type.

Abstract: High permeability cellulose fibers containing enzymes are formed by preparing a solution of nitrocellulose in a solvent that is insoluble in water, preparing an aqueous enzyme solution, mixing together the nitrocellulose and enzyme solutions and emulsifying the mixture, spinning the emulsion into a coagulating bath to produce fibers englobing enzymes and treating the fibers with a reducing agent under conditions which do not damage the enzymes so that nitro groups are removed from the nitrocellulose.