589results about How to "Small molecular weight" patented technology

The invention belongs to the technical field of biological medicines, and relates to an antibacterial polypeptide, a composition and application thereof. The amino acid sequence of the antibacterial polypeptide is as shown in SEQ ID NO. 1: KWKIKWPVKWFKM-NH2. The invention also discloses a preparation method of the antibacterial polypeptide. Experiments show that the antibacterial polypeptide disclosed by the invention has broad-spectrum antibacterial activity on gram-positive bacteria and / or gram-negative bacteria, and also has low cytotoxicity and low hemolysis. The antibacterial polypeptide provided by the invention consists of 14 amino acids, is relatively short in peptide chain, small in molecular weight and easy to artificially synthesize, is a micromolecular polypeptide with extremely high application value, can be used for preparing a novel antibacterial agent, and has a wide application prospect.

The invention discloses a method for catalytically synthesizing lactide by using a kaolin-based catalyst, which comprises the following steps: (1) preparing oligomeric lactic acid: carrying out lactic acid dehydration polymerization reaction by using L-lactic acid or D-lactic acid or DL-lactic acid as a raw material to obtain oligomeric lactic acid of which the weight-average molecular mass of an oligomer is 1000-3000Da; and (2) depolymerizing the oligomeric lactic acid: carrying out depolymerization reaction on the oligomeric lactic acid obtained in the step (1) under the action of a kaolin-based catalyst to obtain crude lactide. The raw materials of the catalyst are easy to obtain, the cost is low, the regeneration process is simple, the reaction temperature of depolymerization cyclization is low, the reaction time is short, and the cost can be greatly reduced in industrial production.

The invention belongs to the field of biological medicine, and relates to an anti-SEZ6 nano antibody or antigen binding fragment and application. The anti-SEZ6 nano antibody or the antigen binding fragment comprises three complementary determining regions, namely, CDR1, CDR2 and CDR3; the sequences of all the regions are respectively shown as SEQ ID NO: 1 to SEQ ID NO: 18. Compared with a conventional antibody, the anti-SEZ6 nano antibody is efficient in expression, simple in purification, small in molecular weight, high in affinity, relatively good in specificity, high in solubility and strong in tolerance, and can be widely applied to the fields of scientific research, diagnosis and treatment.

The invention provides a modified silicone oil agent with a comb-shaped structure as well as a preparation method and application thereof, the oil agent comprises an amino modified silicone oil emulsion and an epoxy modified silicone oil emulsion, and the mass ratio of the amino modified silicone oil emulsion to the epoxy modified silicone oil emulsion is 1: (0.5-1.5); the amino modified silicone oil emulsion and the epoxy group-containing modified silicone oil emulsion have comb-shaped structures, main chains of the amino modified silicone oil and the epoxy group-containing modified silicone oil are acrylate polymers, and branch chains are amino short silane chains or epoxy group-containing short silane chains; the preparation method of the oiling agent comprises the following steps: respectively preparing amino short-chain silicone oil and epoxy group-containing short-chain silicone oil, and then respectively synthesizing amino modified silicone oil emulsion and epoxy group-containing modified silicone oil emulsion. The acrylate polymer is introduced, the content of organic silicon is reduced, the viscosity of the oiling agent is small, carbon fibers are conveniently oiled, a protective film is formed on the fibers, friction and abrasion between the fibers are prevented, and therefore the surface defects of the carbon fibers are reduced.

The invention belongs to the technical field of molecular biology and immunology, and provides an alpaca-derived nano antibody specifically bound with a simian vacuolar virus 40 large T antigen SV40LTA and application of the alpaca-derived nano antibody. The invention relates to a heavy chain antibody, which has a heavy chain variable region VHH, the VHH comprises the following CDR: CDR1 with an amino acid sequence as shown in SEQ ID NO: 1, CDR2 with an amino acid sequence as shown in SEQ ID NO: 2, and CDR3 with an amino acid sequence as shown in SEQ ID NO: 3, the VHH comprises four frame regions of FR1-4, and FR1, FR2, FR3 and FR4 and CDR1, CDR2 and CDR3 are arranged in a staggered manner in sequence. The antibody is high in neutralizing activity and strong in binding capacity with SV40LTA, and the equilibrium dissociation constant is less than 0.1 nM; the monoclonal antibody has the advantages that the monoclonal antibody can effectively recognize SV40LTA, the molecular weight is small, the immunogenicity is small, the solubility and stability are better, and the CDR region is longer; and a potential application value is provided for SV40LTA detection.

The invention provides micron blocky and submicron spherical mixed silver powder and a preparation method thereof. The preparation method comprises the steps that firstly, a silver salt solution is prepared, a reducing agent, a dispersing agent and pure water are mixed to obtain a reducing agent solution, and nano-silver crystal suspension liquid and the dispersing agent are mixed to obtain a base solution; synchronously dropwise adding the silver salt solution and the reducing agent solution into the base solution to obtain a solution containing the mixed silver powder; and finally, the solution is subjected to washing, solid-liquid separation and drying and shaping treatment, and then the micron blocky and submicron spherical mixed silver powder is obtained. According to the preparation method, polyvinylpyrrolidone with low molecular weight is selected as a dispersing agent, and the adding process of the dispersing agent is controlled, so that nano-silver crystals and the dispersing agent play a synergistic role, the micron blocky and submicron spherical mixed silver powder with good dispersion uniformity and high tap density is obtained, and the mixed silver powder is better in stacking structure and high in conductivity after being formed into slurry; the preparation method provided by the invention simplifies the process steps, shortens the preparation time, and has industrial application prospects.

The invention belongs to the technical field of functional foods and health foods, and particularly relates to an anti-saccharification and anti-aging aronia melanocarpa fruit composition and a preparation method thereof. The composition is prepared from the following raw materials in parts by weight: 150 to 400 parts of aronia melanocarpa fruit fermentation liquor, 10 to 80 parts of lycium ruthenicum, 10 to 80 parts of ginseng, 0.5 to 2.5 parts of grape seed extract, 10 to 70 parts of collagen peptide, 0.5 to 4 parts of sodium hyaluronate, 0.1 to 0.8 part of resveratrol and 0.03 to 0.3 part of yeast extract. The content of type I collagen peptide in the skin is increased, the generation of in-vitro anti-glycation end products is inhibited, and the anti-glycation and anti-aging effects are achieved.

The invention relates to a transdermal dipeptide and application thereof, and belongs to the technical field of active polypeptides. A novel transdermal dipeptide Arg-Pro is designed and synthesized, the transdermal dipeptide has obvious penetration enhancing capacity, the penetration enhancing effect of the transdermal dipeptide is better than that of existing penetration enhancers, namely transdermal peptide TD-1, acetyl hexapeptide-1 and menthol, and the transdermal dipeptide is simple in structure, small in molecular weight, high in biocompatibility and free of toxic effects on cells, can be used for preparing penetration enhancing products and has good application prospects. Wide development prospects and application potentials are realized. Meanwhile, transdermal dipeptides Lys-Pro and Asn-Pro are also synthesized, and the transdermal delivery effect of the transdermal dipeptides Lys-Pro and Asn-Pro is slightly lower than that of Arg-Pro, but the transdermal dipeptides Lys-Pro and Asn-Pro still have an obvious penetration promoting effect.

The embodiment of the invention relates to a phycobiliprotein active peptide with a hypoglycemic function and a preparation method and application thereof, and belongs to the technical field of biological active peptides. According to the phycobiliprotein active peptide with the blood sugar reducing function, the amino acid sequence of the phycobiliprotein active peptide is Ser-Tyr-Phe-Asp-Arg-Ala, Ile-Ala-Ser-Tyr-Phe-Asp-Arg, Gly-Tyr-Tyr-Leu-Arg or Val-Ala-Phe-Gly-Arg-Phe, and the amino acid sequence of the phycobiliprotein active peptide with the blood sugar reducing function is shown in the description. The phycobiliprotein active peptide in the embodiment of the invention is separated from spirulina phycobiliprotein, and the spirulina phycobiliprotein is an important protein resource in spirulina and a high-quality source of bioactive peptide, and has wider application; the phycobiliprotein active peptide is low in molecular weight, and compared with a chemically synthesized hypoglycemic preparation, food-borne peptides are safer and more efficient, free of toxic and side effects and easy to digest and absorb; the phycobiliprotein active peptide has high binding affinity with the alpha-glucosidase and the DPP-IV, can form a very stable ligand receptor compound, and has a good inhibition effect on the alpha-glucosidase and the DPP-IV; the compound has excellent inhibition performance on alpha-glucosidase, alpha-amylase and DPP-IV (dipeptidyl peptidase-IV).

The invention provides antibacterial carboxymethyl cellulose hemostatic gauze and a preparation method thereof.The preparation method comprises the steps that carboxymethyl cellulose gauze is soaked in a PBS buffer solution, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbodiimide are added into the PBS buffer solution, and a soaking solution is obtained after uniform mixing; adding the graft modified alginate oligosaccharide into the soaking solution, mixing and stirring to generate grafting reaction, taking out the carboxymethyl cellulose gauze after the reaction is finished, washing and drying to obtain the antibacterial carboxymethyl cellulose hemostatic gauze. According to the preparation method disclosed by the invention, the catechol-grafted modified alginate oligosaccharide and partially carboxymethylated carboxymethyl cellulose gauze are subjected to amidation grafting compounding, so that the hemostatic gauze with excellent antibacterial and hemostatic properties is prepared.

The invention discloses a small-molecule active peptide with antioxidant and hypoglycemic effects, a composition and application, and belongs to the technical field of biological active peptides. The amino acid sequence of the small molecule active peptide with the antioxidant and blood sugar reducing effects is at least one of FSNAPRL, QFGRLY and SVPGHF. According to the invention, a plurality of micromolecular active peptides with antioxidant and hypoglycemic effects are extracted from walnut meal, the obtained peptide fragment sequence is subjected to molecular docking and chemical synthesis, and the antioxidant activity and hypoglycemic activity of a single peptide fragment and a compound peptide fragment of the synthesized peptide fragment are verified. The active peptide and the compound peptide fragment thereof have good DPPH and ABTS clearance rate and alpha-glucosidase and alpha-amylase inhibition ability, so that the active peptide and the compound peptide fragment thereof have good application prospects in preparation of products with antioxidant and hypoglycemic effects, and a foundation is laid for comprehensive utilization of walnut meal byproducts and promotion of research, development and application of functional active peptides.

The invention relates to transdermal tetrapeptide and application thereof, and belongs to the technical field of active polypeptide. A novel transdermal tetrapeptide Ala-Arg-Cys-Gly is designed and synthesized, the transdermal tetrapeptide has obvious penetration enhancing capacity, the penetration enhancing effect of the transdermal tetrapeptide is similar to that of the transdermal peptide TD-1 serving as an existing penetration enhancer and is remarkably superior to that of acetyl hexapeptide-1 and menthol serving as existing penetration enhancers, and the transdermal tetrapeptide is simple in structure, small in molecular weight, high in biocompatibility, free of toxic effect on cells and suitable for being used as a transdermal drug. The method can be used for preparing penetration promoting products and has wide development prospects and application potentials. Meanwhile, transdermal tetrapeptides Arg-Arg-Cys-Gly, Ala-Lys-Cys-Gly and Ala-Arg-Met-Gly are further synthesized, and although the transdermal delivery effect of the transdermal tetrapeptides is slightly lower than that of the Ala-Arg-Cys-Gly, the transdermal tetrapeptides still have an obvious penetration promoting effect.

The invention relates to transdermal tripeptide and application thereof, and belongs to the technical field of active polypeptide. The invention designs and synthesizes a novel transdermal tripeptide Ser-Cys-Arg, the transdermal tripeptide has obvious transdermal ability, the penetration enhancing effect of the transdermal tripeptide is lower than that of acetyl hexapeptide-1, but still better than that of menthol, and the transdermal tripeptide is simple in structure, small in molecular weight, high in biocompatibility and free of toxic action on cells, can be used for preparing penetration enhancing products, and has wide application prospects. Wide development prospects and application potentials are realized. Meanwhile, transdermal tripeptides Ser-Met-Arg and Ser-Cys-Lys are further synthesized, and although the transdermal delivery effect of the transdermal tripeptides is slightly lower than that of the Ser-Cys-Arg, the transdermal tripeptides still have an obvious penetration promoting effect.

The invention relates to the technical field of antibodies, in particular to a Trop2 combined nano antibody, a chimeric antigen receptor and application of the Trop2 combined nano antibody and the chimeric antigen receptor. The Trop2-binding nano antibody provided by the invention can efficiently and specifically recognize and bind Trop2 protein, and can be used for diagnosing and treating diseases taking Trop2 molecules as markers. The invention further provides CAR and CAR-T cells which are combined with the Trop2 protein, and the CAR-T cells have a good Trop2-targeting immune clearance effect, can be used for specifically recognizing and killing cells expressing Trop2, can be used for improving and treating diseases with Trop2 molecules as markers and have a good application prospect in tumor diagnosis and treatment.

The invention discloses a Chinese yam fermented beverage and a preparation method thereof, and relates to the technical field of food processing. The Chinese yam is processed through enzymolysis-extrusion puffing, the molecular weight of Chinese yam starch is reduced, the solubility of the Chinese yam starch is improved, the viscosity of the Chinese yam is reduced, the digestibility of nutritional ingredients such as starch and protein is improved, and release of phenolic substances is promoted. The compound probiotics are adopted for fermentation, the characteristics of reducing sugar and amylose are comprehensively utilized, the content of total sugar (including starch and reducing sugar) in fermentation liquor is reduced, beneficial metabolites such as beta-glucosidase and glucan are generated, and the nutritional value and flavor of the product are improved.

The invention discloses a preparation method and application of active cationic chitosan nanoparticles, which comprises the following steps: reacting a low-molecular chitosan triethylamine hydrogen sulfate ionic liquid ([(C2H5) 3NH] HSO4) solution with an aldehyde compound ethanol solution to form Schiff base protection on chitosan C2-site amino, and then reacting with 2, 3, 5, 6-tetramethyl-4-piperidine-2-one to obtain the active cationic chitosan nanoparticles. The preparation method comprises the following steps: carrying out nucleophilic substitution reaction on chitosan C6 in the presence of a basic catalyst by using 2, 3-epoxypropyl trimethyl ammonium chloride, then adding a chemical initiator, carrying out grafting reaction on chitosan C3 and acrylic acid, and then removing Schiff base protection on chitosan C2. Carboxylate anions of acrylic acid and cations of chitosan are subjected to cross-linking self-assembly through a hydrothermal reaction, and the chitosan nanoparticles which are high in stability, small in particle size, uniform in distribution and efficient and lasting in function are obtained. The prepared nanoparticles are high in reaction activity, contain a large amount of quaternary ammonium salt, amino dication groups and carboxyl groups, and have wide application prospects in the fields of dye adsorption, heavy metal adsorption, textile function finishing and the like.

The invention provides an albumin peptide for promoting growth and development as well as a preparation method and application thereof, and belongs to the technical field of food science. According to the albumin peptide provided by the invention, denatured egg white is taken as a substrate, firstly, chymotrypsin is used for prehydrolysis, after prehydrolysis is completed, the temperature and pH are adjusted, and then alkaline protease and chymotrypsin are added for synergistic hydrolysis. The prepared albumin peptide is small in molecular weight and easy to digest and absorb, and has the effects of promoting growth and development, improving macrophage proliferation capacity, improving immunity and the like.

The invention discloses application of a fusion protein KSa-SspCas9 and a mutant thereof in gene editing, and belongs to the field of genetic engineering. SspCas9 protein in Staphyloccus sp.17KM0847 bacteria is excavated through analysis of bioinformatics, the protein has PAM recognition capability of NNG, a PI structural domain of the SspCas9 protein is fused with a non-PI structural domain of the SaCas9 protein to obtain the fusion protein KSa-SspCas9, and the fusion protein KSa-SspCas9 is used for gene editing. The fusion protein has higher base editing efficiency. Meanwhile, the specific site of the fusion protein is mutated, and the PAM recognition range is greatly widened through PAM sequences of NRN and NYN which can be recognized by mutants. Through discovery of the Cas9 protein and the gene editing system, the variety of gene editing tools is expanded, and the Cas9 protein and the gene editing system have wide application prospects in the aspects of disease treatment, animal model preparation, plant breeding and the like.

The invention discloses a novel polypeptide, a polypeptide derivative and application thereof, and belongs to the technical field of biological medicine. The invention specifically relates to a specific sequence, a discovery process, a specific anti-tumor type, a long-acting modification mode and application of the novel polypeptide. The tumors comprise one or more of brain glioma, neuroblastoma, head and neck cancer, esophagus cancer, thyroid cancer, lung cancer, liver cancer, kidney cancer, breast cancer, cervical cancer, uterine cancer, ovarian cancer, colon cancer, small intestinal cancer, ileocecum cancer, stomach cancer, bladder cancer, pancreatic cancer, prostate cancer, bile duct cancer, melanoma, sarcoma, myeloma, lymphoma and leukemia; the compound has the specific effect of inhibiting proliferation and / or metastasis of tumor cells, is wide in treatment spectrum and has important treatment value in various tumors.

The invention provides a protein degradation targeting chimera based on G-quadruplex RNA (Ribonucleic Acid) as well as a preparation method and application of the protein degradation targeting chimera. The structural general formula of the protein degradation targeting chimera is G-L-E, wherein G is G quadruplex RNA specifically combined with mammal fragile X hypophrenia protein (FMRP), E is a ligand of micromolecule E3 ubiquitination ligase, and L is a connecting arm between the G quadruplex RNA and the ligand of the micromolecule E3 ubiquitination ligase. The protein degradation targeting chimera provided by the invention has the advantages that the stability in an in-vivo environment and the capability of entering cells are greatly improved, and the protein degradation targeting chimera also has the capabilities of efficiently degrading FMRP and changing a secretion mode of cancer cells, so that a lot of convenience is provided for the development of nucleic acid PROTAC drugs.

According to the chlorella pyrenoidosa high-F-value peptide and the preparation method thereof, parameters in the enzymolysis and adsorption processes are strictly controlled, and the enzymolysis of the incision enzyme and the excision enzyme not only can efficiently hydrolyze chlorella protein and generate more peptide fragments with biological activity, but also can be used for preparing the chlorella pyrenoidosa high-F-value peptide. And the characteristics of high industrial production cost and poor stability caused by wide enzyme cutting sites are solved. The prepared chlorella pyrenoidosa high-F-value peptide reaches 36.90 + / -8.18, the F value of the chlorella pyrenoidosa high-F-value peptide is increased by 12.72 times compared with the chlorella pyrenoidosa raw material (2.90 + / -0.07), and in addition, the molecular weight of the high-F-value oligopeptide is 1t; peptides with the molecular weight of 1000 Da account for 95-99.40%, the characteristics of oligopeptides are met, the molecular weight is small, and digestion and absorption are easy. The prepared high-F-value oligopeptide can accelerate metabolism of ethyl alcohol in the liver and protect the liver from being damaged by the ethyl alcohol, and has the effects of dispelling the effects of alcohol and protecting the liver.

The invention relates to low-viscosity sodium alginate, a preparation method and a soft capsule shell containing a pure sodium alginate component, and belongs to the technical field of biochemical engineering, the viscosity and molecular weight of the low-viscosity sodium alginate are 15mPa. S and 273.08 kDa; the molecular weight is 30 mPa.s and the molecular weight is 310.5 kDa; according to the present invention, the ratio of the Da to 665.43 kDa is 20.48%, the ratio of the Da to 444.79 kDa is 16.87%, and the ratio of the Da to 322.06 kDa is 62.66%; or when the molecular weight is 70 mPa.s, the molecular weight of 466.92 kDa accounts for 44.27%, and the molecular weight of 329.27 kDa accounts for 55.73%. The invention also provides a preparation method of the low-viscosity sodium alginate, which comprises the following steps: dissolving the sodium alginate as a raw material, carrying out enzymolysis by using alginate lyase, sampling at regular time, measuring the viscosity, carrying out enzyme deactivation treatment on the enzymatic hydrolysate when the viscosity reaches the specified viscosity, and carrying out evaporation concentration, alcohol precipitation, drying and crushing to obtain the low-viscosity sodium alginate. The low-viscosity sodium alginate can be used for preparing a soft capsule shell which is stable in property and good in enteric characteristic.

The invention discloses a cationic coating digital ink-jet printing pretreatment liquid and a preparation method and application thereof, and the preparation method comprises the following steps: in the presence of a chain transfer agent, copolymerizing a cationic monomer and a water-soluble nonionic monomer to obtain the cationic coating printing pretreatment liquid; the pretreatment liquid is finished on the fabric, the pretreatment liquid and electronegative coating particles printed on the fabric through jet printing form electrostatic attraction through the cationic property of the pretreatment liquid, the electronegative coating particles are deposited on the surface of the fabric, permeation is avoided, and the apparent color yield of the fabric is improved; meanwhile, as the electrostatic adsorption efficiency is high, the slurry amount for pretreatment is reduced, the influence of the slurry on the hand feeling of the fabric is small, and the hand feeling of the jet-printed fabric is improved. Besides, benefited from the control of the chain transfer agent and the copolymerization of the hydrophilic monomer, the resin in the pretreatment liquid is low in molecular weight, high in water solubility and easy to wash away, and the staining resistance of the pigment printed fabric is also improved when the pigment printed fabric is worn and washed with water.

The invention discloses a Keemun black tea fermentation product, a preparation method thereof and application of the Keemun black tea fermentation product in caenorhabditis elegans anti-aging research. Active components in the black tea can be more fully extracted by using the natural eutectic solvent, and then the active components are further fermented by sequentially using the lactobacillus and the thermophilic thermophilic bacteria, so that the Keemun black tea fermentation product is prepared. The Keemun black tea fermentation product prepared by the invention is applied to caenorhabditis elegans anti-aging research, and adverse effects caused by oxidative stress are relieved through the antioxidant effect of the Keemun black tea fermentation product, so that the antioxidant enzyme activity (SOD, CAT and GSH) of caenorhabditis elegans is remarkably improved, and the metabolite (MDA) is remarkably reduced; and the ROS level in the caenorhabditis elegans is also obviously reduced. Therefore, the Keemun black tea fermentation product prepared by the invention has better antioxidant activity, and can effectively improve the oxidative stress damage of the caenorhabditis elegans, thereby effectively prolonging the life of the caenorhabditis elegans.

The invention belongs to the technical field of food microbial fermentation, and particularly relates to modified fucoidin, a preparation method thereof and application of the modified fucoidin in regulating an intestinal flora structure. The method comprises the following steps: inoculating a fermentation culture medium containing fucoidin with an activated bifidobacterium longum seed solution, carrying out anaerobic fermentation, taking a supernatant, desalting, and drying to prepare the modified fucoidin. The main chain structure and monosaccharide composition of the modified fucose fructose are unchanged, and the content of sulfuric acid groups of the modified fucose fructose is reduced by 25%-35% compared with that before modification. When the modified fucoidin is used for regulating the intestinal flora, the molecular weight of the modified fucoidin is reduced to 15% or below compared with that before modification, the proportion of the intestinal beneficial flora can be remarkably increased, the intestinal utilization rate of the modified fucoidin by the intestinal flora is increased, and a basis is provided for subsequent research and development of food for improving the intestinal beneficial flora.

The invention provides whitening and moisturizing essence as well as a preparation process and application thereof, and belongs to the technical field of cosmetics. The essence is prepared from tranexamic acid, nicotinamide, macromolecular hyaluronic acid, micromolecular hyaluronic acid, hexapeptide-2, an althaea rosea flower extract, a rhodiola sachalinensis extract, a glycyrrhiza glabra extract, a coast pine needle extract, a polyhydric alcohol humectant, vegetable fat and the like. Wherein the hollyhock flower extract, the rhodiola sachalinensis extract, the glycyrrhiza glabra extract and the coast pine needle extract are respectively obtained by adopting a special enzymolysis method. The tranexamic acid and the nicotinamide are used for synergistically whitening, the hyaluronic acid, the polyhydric alcohols and the vegetable fat are used for jointly moisturizing, the plant extract is used for enhancing oxidation resistance, whitening and safety, the components are ensured to be uniform and stable through a reasonable preparation process, and the effect of the essence is favorably improved.

The invention belongs to the technical field of biology, and particularly relates to recombinant III-type humanized collagen as well as a preparation method and application thereof. On the basis of the III-type human collagen amino acid sequence, the amino acid sequence is designed by means of bioinformatics and the like, so that the recombinant collagen realizes higher expression efficiency and a triple helix structure on the premise of maintaining high biological activity, a section of brand new collagen sequence containing 180 amino acids is designed, the protein molecular weight is small, and the recombinant collagen has the advantages of high expression efficiency, high yield, high yield and the like. The skin permeability is better. Compared with a commercially available collagen product, the recombinant humanized collagen prepared by the technical scheme has better stability, cell proliferation and migration promotion effect and barrier repair capability, so that the recombinant humanized collagen has good practical application value.

The invention discloses a low-cost temperature-resistant quick-drying polyether solvent adhesive and a preparation method thereof, and belongs to the field of polyurethane adhesives for composite flexible packages. The solvent type adhesive is prepared by mixing a component A and a component B according to a weight ratio of 1: (0.8-1.2), wherein the component A is hydroxyl-terminated resin obtained by carrying out polymerization reaction on a mixture of polyester polyol and polyether polyol and isocyanate; and the component B is isocyanate-terminated resin obtained by carrying out polymerization reaction on a mixture of two polyether polyols and isocyanate. By adjusting the proportion of polyester and polyether in the component A and the proportion of polyether polyol with different molecular weights in the component B, the temperature required for reaction of the component A and the component B is low, the reaction speed is high, the crosslinking degree of an adhesive film after reaction is high, and the polyether adhesive can be cured at low temperature, and is short in curing time and good in heat resistance.

The invention relates to high-purity resistant dextrin and a preparation method thereof, and belongs to the technical field of starch processing.According to the technical scheme, a resistant dextrin semi-finished product with the high dietary fiber content is obtained through the synergistic effect of steam explosion assisted acidolysis, high-temperature treatment, ultrahigh-pressure treatment and enzymolysis treatment; and obtaining the high-purity resistant dextrin through a series of refining processes. Through the synergistic effect of steam explosion and ultrahigh pressure treatment, the solubility of pyrodextrin is remarkably improved, and meanwhile, the molecular weight of starch is reduced through steam explosion assisted acidolysis and high-temperature treatment; therefore, the resistant dextrin with high dietary fiber content can be obtained by using a small amount of alpha-amylase and trans-glycosidase and performing enzymolysis for a short time. The use amount of alpha-amylase and transglycosidase is small, so that the pollution of zymoprotein to a filter membrane or resin is reduced.

The invention provides a polylactic acid material environment-friendly skin-friendly natural antibacterial double-layer fabric and a preparation method thereof, and belongs to the technical field of fabrics. Polylactic acid long fibers, combed long stapled cotton yarns and antibacterial spandex are combined, a double-sided circular knitting machine is adopted for weaving, grey cloth is woven according to a designed organization structure, the grey cloth is subjected to pre-shaping, hair removal through cellulase, dyeing through reactive dye and disperse dye, liquid ammonia finishing is conducted after drying is conducted through loose drying equipment, and the antibacterial fabric is obtained. During shaping, soft oil finishing and preshrinking finishing are carried out, and the polylactic acid material environment-friendly skin-friendly natural antibacterial double-layer fabric is prepared. The polylactic acid fiber is combined with high-quality cotton yarn and antibacterial spandex, and meanwhile, the polylactic acid material environment-friendly skin-friendly natural antibacterial double-layer fabric is prepared through the special design of a weaving method and the working procedures of enzyme washing treatment, liquid ammonia treatment, silicone oil treatment and the like.