16 results about "Ascorbic acid" patented technology

The invention relates to the technical field of cell culture, and in particular to a serum-free culture medium, a preparation method thereof and a culture method of mesenchymal stem cells. The culturemedium consists of the following components: non-essential amino acid, glutamine, hydrocortisone, dexamethasone, polyvinyl alcohol, recombinant human insulin, recombinant human transferrin, a recombinant human epidermal growth factor, a recombinant human basic fibroblast growth factor, a recombinant human Wnt-3a protein, a recombinant human fibronectin, recombinant human laminin, L-glutathione, L-ascorbic acid, beta-mercaptoethanol, ethanolamine, Pluronic F-68, Tween 80, cholesterol, adenine, sodium selenite and a basic culture medium. According to the invention, polyvinyl alcohol can replaceserum albumin in a serum-free culture medium in carrier function, so that proliferation capacity of mesenchymal stem cells is effectively improved. Polyvinyl alcohol has more stable performance thanserum albumin, and the problem that proliferation capacity and passage capacity of stem cells are reduced can be effectively solved.

Compositions include vitamin C, water and a reducing sugar, result in increased stability of vitamin C. Further the addition of alcohol to aqueous vitamin C compositions increased the stability of vitamin C. Moreover, aqueous vitamin C compositions having surfactant included therein enhance the absorption of vitamin C into skin. Methods of using the stable vitamin C compositions are also described.

The invention belongs to the technical field of clinical in vitro diagnostic reagents and relates to a dry chemical reagent tablet for quantitatively measuring the concentration of total cholesterol and a preparation method of the dry chemical reagent tablet. The dry chemical reagent tablet comprises four laminations which are respectively a support layer, a color developing layer, a reagent layerand a diffusion layer distributed sequentially; and reagents in the reagent layer include a buffer system, a hydrophilic colloid, peroxidase, an activator, a surfactant and a stabilizer; and reagentsin the color developing layer include a chromogen and a hydrophilic colloid. Compared with the prior art, the dry chemical reagent tablet and the preparation method thereof of the invention have theadvantages of simple operation process, high stability, high good repeatability and high accuracy of detection results, quantitative detection, wide linear range, simple and convenient preparation process, easiness in operation, low risk and low pollution. According to the dry chemical reagent tablet and the preparation method of the dry chemical reagent tablet of the invention, the reagents do not need to be prepared, and samples can be directly added dropwise; the reagent tablet is dry and is free of moisture; the diffusion layer has a filtering function, so that hemolysis, bilirubin and ascorbic acid samples exert no significant interference on measurement results.

The invention relates to a quickly frozen steamed bun raw product and a production method thereof, belonging to the technical field of food processing. Wheat flour, Yanshan yeast, aluminum-free baking powder, white granulated sugar, shortening, salt, transglutaminase, lipase, xylanase, glucose oxidase, trehalose, ascorbic acid, lecithin, sugar ester, glycerol, locust bean gum, artemisia gum, carboxymethylcellulose, guar gum, wheat gluten, wheat starch, or corn starch, or potato starch or rice starch are put in a mixing tank, are slowly agitated and are evenly mixed, water is added in the mixture and the obtained mixture is agitated into dough at medium-speed; the dough is pressed and formed, the obtained dough is quickly frozen after the bough is pre-fermented and cooled or the obtained dough is directly and quickly frozen, and the obtained dough is frozen for future use; and when in use, the dough is directly steamed only to obtain fresh bun products, and for dough not pre-fermented,pre-fermentation is required before steaming. The invention has the advantages that the traditional manual workshop production of the steamed bun is shifted to industrial production in an accelerating way, the product quality, the safety and the convenience are improved, the flavor loss caused by repetitive steaming is avoided and the energy is saved when compared with the steamed bun products quickly frozen after steaming.

The invention discloses application of sucrose phosphorylase in preparation of 2-O-alpha-D-glucosyl-L-ascorbic acid. According to the application, a reaction system is formed by taking fermentation liquor, obtained through fermenting sucrose phosphorylase gene containing engineering bacteria, or broken liquor, obtained through resuspending wet thalli obtained after centrifuging the fermentation liquor with a buffer solution, as a catalyst, taking L-ascorbic acid as a substrate, taking sucrose as a cosubstrate and taking a buffer solution with a pH of 4.8 to 6.0 as a reaction medium, and a reaction is carried out at the temperature of 30 DEG C to 55 DEG C, thereby obtaining AA-2G. According to the application, the AA-2G is efficiently produced by employing the sucrose phosphorylase, the yield is 3.47g/L/h and is increased by 34.5% compared with that employing the existing reported B. longum derived sucrose phosphorylase, and the maximum concentration of the AA-2G can reach 178g/L; and recombinant bacillus subtilis can efficiently secrete and express the sucrose phosphorylase, and the fermentation liquor is directly applied to preparation of food-grade AA-2G.

The invention discloses an aluminum-magnesium alloy electroplating solution which is composed of 20-35 g/L nickel sulfate, 15-25 g/L chromic sulfate, 15-35 g/L copper sulfate, 1-5 g/L cobalt acetate, 50-80 g/L tetrahydrothiazolyl thione, 10-20 g/L citric acid, 1-5 g/L ascorbic acid, 10-40 g/L sodium oxalate, 40-50 g/L sodium borate, 20-35 g/L potassium citrate and the balance of deionized water. The aluminum-magnesium alloy electroplating solution can solve the problem of high corrosion tendency of the aluminum-magnesium alloy in the electroplating construction, and can enhance the binding force of the coating.

The invention discloses a preparation method for solar blind type deep ultraviolet plasma resonance nanoparticles. A laser liquid phase ablation device is adopted. A laser liquid phase ablation methodis used for preparing metal nanoparticles with a local area surface plasma resonance effect; the preparation method is simple; and a reaction product is pure, so that impurities are not easily introduced. Ascorbic acid is introduced as a carbon source, so that the metal nanoparticles can be wrapped with a carbon layer with a certain thickness, and the stability and oxidation resistance of the product can be effectively improved. The experimental controllability is high. By adjusting laser energy and ablation time, the particle size and the oxidation degree of the metal nanoparticles can be regulated and controlled. The prepared metal nanoparticles can be used for enhancing the light absorption of light (240-260nm) in the extremely deep ultraviolet waveband.

The invention discloses a precious metal anti-cancer nano material and a preparation method and application thereof.The preparation method comprises the steps that a chloroauric acid aqueous solution, a chloroplatinic acid aqueous solution and a copper chloride aqueous solution are evenly mixed, an ascorbic acid aqueous solution is added, heating is conducted for 1-4 h at the temperature of 30-60 DEG C, a product is centrifugally washed, and the precious metal anti-cancer nano material is obtained. The precious metal anti-cancer nano material with the face-centered cubic structure can be obtained. According to the preparation method of the precious metal anti-cancer nano material, the problem that in the prior art, the preparation conditions for preparing the precious metal-transition metal alloy nano material are harsh and tedious is solved. And the reaction is carried out in a water phase without adding an organic solvent or a surfactant, so that the prepared precious metal anticancer nano material can be prevented from being polluted by reagents.

The invention discloses a preparation method of a silver-coated gold nanorod. The method comprises the following steps that a NaBH4 solution is prepared and is inserted into ice for at least 10 min; a cetyltrimethylammonium bromide (CTAB) solution is added into a container, the container is placed into a water bath at 30 DEG C, and stirring is performed at the speed not higher than 600 rpm; a HAuCl4 solution is added into the CTAB solution, then the NaBH4 solution is added under violent stirring at the speed not lower than 1000 rpm, and a brown seed solution is obtained; after 5 min, the seed solution stands in a water bath for 1 h; an AgNO3 aqueous solution is added into the CTAB solution under the condition of the stirring speed not higher than 600 rpm and the temperature being 30 DEG C, and then the HAuCl4 solution, the ascorbic acid solution and the seed solution are added to obtain a colorless mixed solution; the colorless mixed solution is stirred for 1 min and then stands in the dark for 1 h; the mixed solution obtained after standing is transferred into an Eppendorf tube, centrifugation is conducted to remove supernate, and solution sediment is obtained; the solution precipitate is resuspended in phosphate buffer saline water, and the gold nanorod is obtained; and a silver coating is formed on the surface of the gold nanorod.

The invention discloses low-sugar fingered citron jam and a preparation method thereof. The fingered citron jam is prepared from the following raw materials in parts by weight: 55 to 75 parts of fingered citron pulp, 5 to 15 parts of stachyose, 5 to 15 parts of isomalto-oligosaccharide, 3 to 10 parts of pectin, 0.1 to 1 part of L-ascorbic acid and 0.1 to 1 part of citric acid. The preparation method of the fingered citron jam comprises the steps of pre-treating the raw materials, pre-boiling, pulping, blending, concentrating, filling and sterilizing. The low-sugar fingered citron jam providedby the invention is low in sugar content and is suitable for special crowds including diabetic patients and the like to eat; meanwhile, the low-sugar fingered citron jam has the effects of tonifying spleen and appetizing, and regulating intestines.

The invention belongs to the technical field of medicines, and discloses a novel 3-O-(para-methanesulfonate benzyl)-ascorbic acid compound with anti-cancer activity and a preparation method thereof. The compound has the advantages that the synthesizing route is simple, the reaction condition is mild and environment-friendly, the yield is higher, and the good inhibiting activity on human colon cancer cell RKO, human lung cancer cell A549, human breast cancer cell MDA-231 and human melanoma cell B16-F10 is realized.

The invention belongs to the technical field of etching antennas, and particularly relates to a corrosion inhibitor for reducing lateral etching of etching antennas. The corrosion inhibitor is prepared from the following raw materials in parts by weight: 3-7 parts of urotropine (hexamethylenetetramine), 2-5 parts of thiourea, 16-28 parts of chlorinated poly (N-carboxymethyl-4-vinyl pyridine) salt,7-10 parts of EDTA (ethylene diamine tetraacetic acid), 6.5-10.5 parts of maleic anhydride, 4-8 parts of citric acid, 6-8 parts of ascorbic acid, 8-12 parts of sodium percarbonate, 2-5 parts of polyethylene glycol and 28-48 parts of deionized water. The corrosion inhibitor is non-toxic and harmless, the overall etching speed can be increased, meanwhile, the local etching speed is decreased, lateral etching can be reduced as much as possible while it is guaranteed that etching is thorough in the process of overall etching, and the etching process can be operated stably and evenly.