摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method is disclosed for improving the activity of oxireductase enzymes, the improvement consisting in that an enzyme and a previously functionalized coenzyme are embedded in a filamentary structure, the coenzyme having previously been attached to a water-soluble, high-molecular-weight polymer.
摘要:
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.
摘要:
Oily hydrocarbons which pollute the surface of water are removed therefrom by scattering over the polluted surface solid particles of nutrient salt containing nitrogen and phosphorous in a form that is readily assimilable by aqueous microorganisms capable of metabolizing hydrocarbons. The particles of nutrient salt are given a surface pretreatment with paraffine so that they are buoyant and only slowly soluble in water and lipophilic.
摘要:
This invention relates to a process for the preparation of D(-) mandelic acid by the acid hydrolysis of the corresponding carbamate in an aqueous environment at a temperature of between 40.degree. and 100.degree. C. and at a pH of between 1 and 3.5.The invention also relates to a process for the enzymatic hydrolysis of racemic 5-substituted 2,4-oxazolidinediones to give only one of the two possible optical isomers, i.e., the D-carbamyl-.alpha.-hydroxy acid. The free D-.alpha.-hydroxy acid can be obtained from the optically active carbamyl derivative by simple hydrolysis. Of particular interest is the case in which the D-.alpha.-hydroxy acid is D(-)mandelic acid. The enzymatic activity required for preparing the carbamyl derivative of D(-)mandelic acid has been found both in homogenised veal liver and in a series of microorganisms, including Agrobacterium radiobacter, Bacillus brevis, Bacillus stearothermophilus, Pseudomonas sp., Pseudomonas desmolytica, Pseudomonas fluorescens, Pseudomonas putida.