12 results about "Sodium phosphate buffer" patented technology

The application discloses a preparation method of structural stable porous starch, which comprises the following steps: adding a hydrophilic colloid into deionized water to prepare a solution, then adding starch, mixing uniformly to obtain a compound suspension, heating the compound suspension at a crystal starting melting temperature, then performing vacuum freeze drying, grinding and sieving to obtain melting coated starch, adding the melting coated starch into a citric acid-sodium phosphate buffer solution, mixing uniformly to obtain a starch-buffer solution suspension, adding an enzyme to perform oscillation reaction, adjusting the reaction solution to alkaline to terminate the reaction after the reaction is completed, then adjusting the reaction solution to neutral, finally performing centrifugation, washing, vacuum freeze drying, grinding and sieving to obtain the structural stable porous starch. The method has the advantages of simple process and low manufacturing cost, and the prepared porous starch has excellent adsorption, structural stability and thermal stability, and solves the problems of complex manufacturing process, long preparation time, poor structural stability of the prepared porous starch and limited pore forming effect in the prior art.

To provide formulations of protein molecules comprising iduronate 2-sulfatase.SOLUTION: Certain embodiments provide a pharmaceutical composition comprising a protein molecule comprising an ERT enzyme-Fc fusion polypeptide and a modified Fc polypeptide, a buffer, an isotonicity agent, a surfactant, and a stabilizer, wherein the pH of the pharmaceutical composition is about 5.5 to 7.0, and further provide methods of use thereof. In certain embodiments, the buffer is selected from the group consisting of phosphate buffer, acetate buffer, arginine buffer, and histidine buffer. In certain embodiments, the phosphate buffer is a sodium phosphate buffer or a potassium phosphate buffer.SELECTED DRAWING: None

The invention belongs to the technical field of biological enzyme preservation, and particularly relates to a bromelain freeze-drying protective agent and a preparation method thereof. The trehalose and pulullan compound freeze-dried powder injection is prepared from the following components in parts by weight: 30 to 50 parts of trehalose, 8 to 10 parts of pulullan, 3 to 10 parts of maltodextrin, 12 to 22 parts of mannitol, 1 to 4 parts of sorbitol, 4 to 12 parts of glycine, 0.05 to 0.2 part of polysorbate-20, 1.5 to 4.5 parts of a buffering agent, 0.2 to 0.8 part of N-acetylcysteine, 0.05 to 0.3 part of oxidized glutathione, 0.8 to 2.5 parts of PEG (Polyethylene Glycol) and 0.05 to 0.3 part of an antioxidant. According to the invention, trehalose-pullulan is taken as a main skeleton, so that the growth of ice crystals is inhibited, and the water activity is reduced; mannitol constructs a crystal phase support network, and polysorbate-20 stabilizes an interface; sulfydryl is temporarily sealed through oxidized glutathione, and controllable reduction during redissolution is realized through microencapsulated N-acetylcysteine; and a sodium phosphate buffer system keeps the pH stable.

The present application belongs to the technical field of biological enzyme preservation, and particularly relates to a bromelain freeze-drying protective agent and a preparation method thereof. The composition comprises the following components: 30-50 parts of trehalose, 8-10 parts of pullulan, 3-10 parts of malt dextrin, 12-22 parts of mannitol, 1-4 parts of sorbitol, 4-12 parts of glycine, 0.05-0.2 parts of polysorbate-20, 1.5-4.5 parts of a buffer, 0.2-0.8 parts of N-acetylcysteine, 0.05-0.3 parts of oxidized glutathione, 0.8-2.5 parts of PEG and 0.05-0.3 parts of an antioxidant. The present application takes trehalose-pullulan polysaccharide as a main skeleton, inhibits ice crystal growth and reduces water activity; mannitol constructs a crystal phase support network, and polysorbate-20 stabilizes the interface; oxidized glutathione temporarily seals mercapto groups, and microencapsulated N-acetylcysteine realizes controllable reduction during redissolution; and a sodium phosphate buffer system maintains pH stability.

The invention discloses a method for preparing psicose by catalyzing fructose conversion through immobilized isomerase, and belongs to the technical field of sweeteners, the method comprises the following steps: glycosylation of DAEase enzyme, preparation of a lectin carrier, immobilization of glycosylated DAEase enzyme, and catalytic preparation of psicose; the method for immobilizing the glycosylated DAEase enzyme comprises the following steps: dispersing the glycosylated DAEase enzyme and a lectin carrier in a sodium phosphate buffer solution, stirring at room temperature for 1-1.2 hours, centrifuging to remove supernate, adding into a glutaraldehyde solution, cross-linking at room temperature for 1-1.5 hours, and freeze-drying to obtain the immobilized isomerase, according to the method disclosed by the invention, the activity of the immobilized enzyme, the conversion rate of D-fructose and the catalytic rate of DAEase are improved.

The invention discloses a cathode plate surface sulfuration treatment method and a sulfuration treatment surface thereof, and relates to the technical field of cathode plate surface treatment.The cathode plate surface sulfuration treatment method comprises the following steps that after a cathode plate is pretreated, pulse current deposition is conducted in sulfuration liquid, and after-treatment is conducted, the cathode plate can be obtained; the vulcanizing liquid comprises a sulfur source, ammonium citrate, hydroxylated carbon nanotubes, potassium perfluorohexyl sulfonate and a boric acid-disodium hydrogen phosphate buffer system; the sulfur source is at least one of thiosulfate, thiourea or sodium sulfide. The porosity of the vulcanized surface is less than or equal to 2.0%, the uniformity is less than or equal to 5%, and the vulcanized surface has good adhesive ability.

The application discloses a triglyceride and cholesterol mixed quality control liquid and a preparation method and application thereof, relates to the technical field of in vitro diagnostic reagents, and solves the problem of poor compatibility of components of the triglyceride and cholesterol mixed quality control liquid. The triglyceride and cholesterol mixed quality control liquid comprises a mother liquor and a diluent, the mother liquor comprises the following components in percentage by mass: glyceryl trioleate 7-10%, Triton X-100 85-90% and cholesterol 3-5%; and the diluent comprises the following components in percentage by mass: isopropyl alcohol 50-51%, sodium phosphate buffer 39-40%, sodium cholate 9.50-9.75% and sodium benzoate 0.25-0.50%. The mixed quality control liquid is high in stability and accuracy, can detect triglyceride and cholesterol at the same time, and the detection results do not interfere with each other.

The invention relates to the technical field of enzyme extraction, in particular to an extraction method of hermetia illucens superoxide dismutase, which comprises the following steps: homogenizing hermetia illucens larvae by a bead mill at 8 DEG C, mixing the homogenized hermetia illucens larvae with 0.3 mol / L sodium phosphate buffer solution with pH of 8.6 according to a liquid-solid ratio of 6.0 mL / g, standing and centrifuging to obtain crude extract enzyme liquid; adjusting the pH value to 6.8, standing and centrifuging to obtain a primary purified enzyme solution; performing fractional precipitation and centrifugation by using ammonium sulfate to obtain a secondary purified enzyme solution; then adding a specific metal salt solution, heating in a water bath and centrifuging to obtain a third-stage purified enzyme solution; and finally, dialyzing, desalting and freeze-drying to obtain the high-purity SOD powder. According to the method, multiple extraction and purification technologies are combined, impure protein is greatly removed, the enzyme activity is reserved, the used reagent is an inorganic reagent and is environmentally friendly, the technical blank is filled, the additional value of the hermetia illucens can be increased, and the method has wide industrial application prospects.

The invention discloses a method for extracting lily polysaccharide from lily, and belongs to the technical field of lily polysaccharide extraction. The method comprises the following steps: washing and drying lily bulbs, cutting the lily bulbs into pieces, adding pure water for washing, standing the washing liquid, layering the washing liquid with water after starch is completely precipitated, and taking the lily bulbs and supernate; drying the washed lily bulbs, and sieving to form lily bulb powder; mixing the lily bulb powder, the supernate and pure water, stirring, extracting at constant temperature and constant pressure, and cooling to obtain an extracting solution; mixing the sodium phosphate buffer solution and the extracting solution for pre-incubation to obtain a mixed solution; pre-incubating amyloglucosidase, adding the pre-incubated amyloglucosidase into the mixed solution, mixing and hydrolyzing, and terminating the reaction by using a DNS reagent. According to the method, the total sugar extraction rate is remarkably increased, the starch component in the bulbs is effectively removed, and polysaccharide with higher purity is obtained. Subcritical water is used as a solvent in the extraction process, pollution of an organic solvent is avoided, the process is more environmentally friendly, and operation is easy and convenient.

The invention belongs to the field of collagen extraction, and particularly relates to a preparation method of a high-stability I-type collagen solution for injection and an obtained product. The method is realized by the following steps: firstly, pretreating a type I collagen freeze-dried product; and sequentially adding a sodium hyaluronate mixed solution and a chitosan mixed solution 3, fully and uniformly mixing, and adding a disodium hydrogen phosphate buffer solution to obtain the I-type collagen solution for injection. The preparation method disclosed by the invention is simple and easy to operate, the prepared animal-derived I-type collagen solution for injection is relatively good in uniformity and stability, and the selected components are safe and relatively excellent in effectiveness. The type I collagen and the chitosan have good effects of promoting cell proliferation, migration and repair, and related repair products are sold on the market; the type I collagen and the sodium hyaluronate have a good moisturizing effect; the trehalose component has good moisturizing and anti-oxidation effects, and particularly, the trehalose has excellent characteristics of keeping cell viability and biomacromolecule activity; the mannitol component has a good effect of improving the osmotic pressure molar concentration of the solution, the osmotic pressure of the solution can be basically kept consistent with the osmotic pressure of body fluid in the solution, and side effects such as edema are not prone to occurring.

This invention relates to a method for degrading PET fibers using a mechanical enzymatic method and recycling the degradation products, comprising: (1) extracting crude enzyme solution using screened PET-degrading strains. When the bacteria are in the late logarithmic growth phase, the supernatant of the culture medium is collected by centrifugation, and then placed in a freeze dryer to remove water from the crude enzyme solution, thereby obtaining the desired enzyme powder. (2) accurately weighing a certain amount of PET and placing it in a homogenizer, adding a certain amount of enzyme powder and sodium phosphate buffer with added green surfactant, performing preliminary mechanical treatment using a homogenizer, and then incubating the treated mixture at a constant temperature. (3) reacting the degradation products in the solid reaction mixture with sodium carbonate solution, filtering through cotton, and then acidifying with hydrochloric acid to precipitate substances such as terephthalic acid. Finally, centrifuging is used to remove the acidic supernatant to separate the degradation products such as terephthalic acid. This process avoids the use of large amounts of solvent, reduces costs and environmental impact, realizes the direct enzymatic hydrolysis of highly crystalline PET fibers, and simultaneously achieves high-purity recovery of degradation products, which can be recycled for the production of new PET products.

The present invention relates to a method for synthesizing α-Fe2O3 / Fe3O4 nanoparticles having Bst3 polymerase immobilized on their surface, the method being characterized in that it comprises the following steps: 1) synthesis of α-Fe2O3 / Fe3O4 nanoparticles; a) dissolving chitosan in an acid solution to obtain a chitosan solution; b) adding a glutaraldehyde solution to the chitosan solution; c) stirring to form a chitosan hydrogel; d) mineralizing magnetic nanoparticles in the chitosan hydrogel; e) resuspending the chitosan hydrogel in distilled water in an FeCl3 solution at least once to form a CS-Fe complex; f) wetting the CS-Fe complex with a NaOH solution to obtain a black magnetite / chitosan compound; g) degrade the magnetite / chitosan compound in acetic acid and an H2O2 solution to obtain magnetic chitosan nanoparticles;h) Recover the α-Fe2O3 / Fe3O4 nanoparticles by centrifugation; i) Functionalize the α-Fe2O3 / FeO4 nanoparticles; 2) Immobilization of the Bst3 polymerase; a) Take a sample of 0.5 to 1.5 g of functionalized magnetic nanoparticles; b) Mix the functionalized magnetic nanoparticles with glutaraldehyde to a final concentration of 2 to 5%; c) Wash the functionalized magnetic nanoparticles with sodium phosphate buffer and resuspend them in the same buffer; d) Immobilize the Bst3 polymerase by mixing 7,000 to 15,000 units of enzyme with the nanoparticles suspended in sodium phosphate buffer; e) Mix the nanoparticles suspended in sodium phosphate buffer with the enzyme by stirring for 18 to 30 hours; f) separate the nanoparticles suspended in sodium phosphate buffer mixed with the enzyme using a magnet and resuspend them in a sodium phosphate buffer containing 20 to 30% sterile glycerol.;