949 results about "Disulfide bonding" patented technology

The invention discloses silk fibroin composite gel and a preparation method thereof, and relates to the technical field of tissue filling materials. The preparation method of the silk fibroin composite gel comprises the following steps: preparing silk fibroin and carrying out amination modification on the silk fibroin to obtain aminated silk fibroin; carrying out dynamic cross-linking on the aminated silk fibroin and the oxidized sodium alginate through a Schiff base bond by adopting an enzyme catalysis cross-linking process to obtain a dynamic cross-linked network solution; adding a temperature-sensitive component into the dynamic cross-linked network solution, and uniformly mixing to obtain a temperature-sensitive-dynamic dual-network pre-gel solution with temperature responsiveness; loading the active component into the temperature-sensitive-dynamic dual-network pregel solution to obtain a composite gel solution; incubating the composite gel solution to obtain primary gel; after disulfide bonds are introduced into the primary gel, cross-linking strengthening and sterilization are carried out, and the silk fibroin composite gel is obtained. Through temperature-sensitive-dynamic dual-network design, active components and disulfide bonds are introduced to strengthen crosslinking, and the problems that traditional injectable gel is irreversible, single in function, prone to collapse after being filled and the like are systematically solved.

The invention relates to the technical field of films, in particular to a flexible film special for a handwriting board and a preparation method of the flexible film. The flexible film is obtained by coating a release film with coating slurry and carrying out thermocuring, wherein the coating slurry contains modified polyurethane, a flatting agent, a defoaming agent and ethyl acetate. According to the modified polyurethane, polycarbonate diol, isophorone diisocyanate and other raw materials are subjected to a reaction, and a nano particle chain extender containing disulfide bonds is added. The nano particle chain extender containing disulfide bonds is prepared by modifying nano silicon dioxide and grafting cystamine dihydrochloride and diamino polyethylene glycol. Through nanoparticle surface modification and dynamic disulfide bond network construction, molecular-level coupling of a rigid reinforced phase and a flexible substrate, inhibition of nanoparticle aggregation and balance of strength and toughness are realized, the dynamic disulfide bond network can self-repair microcracks, and a high-quality special flexible film solution is provided for a high-performance handwriting board.

The embodiment of the invention relates to the field of energy storage, and provides a secondary battery and a preparation method thereof, an energy storage system and electric equipment. The negative electrode active material comprises a silicon-based material, honeycomb porous graphite and a polypyrrole layer, the surface of the honeycomb porous graphite is coated with the polypyrrole layer, the silicon-based material is embedded in pores of the honeycomb porous graphite, and the silicon-based material comprises silicon particles, a poly N-isopropylacrylamide layer and a disulfide bond-containing polyaniline layer. The poly (N-isopropylacrylamide) layer and the disulfide bond-containing polyaniline layer are coated on the surfaces of the silicon particles, the poly (N-isopropylacrylamide) layer is positioned between the silicon particles and the disulfide bond-containing polyaniline layer, and the honeycomb porous graphite comprises a graphite flake and a carbon layer which is positioned on the surface of the graphite flake and is of a honeycomb pore structure. The secondary battery formed by assembling the negative electrode active material disclosed by the invention has relatively high cycling stability, high temperature resistance, rate capability, gram volume and safety.

The invention discloses a light-moisture dual-curing underwater epoxy coating with a self-repairing function as well as a preparation method and a construction method of the light-moisture dual-curing underwater epoxy coating. The epoxy coating comprises a component A and a component B, wherein the mass ratio of the component A to the component B is (1.5-3.5): 1; the component A is prepared from the following raw materials: bisphenol F type epoxy resin, dynamic disulfide bond modified polysulfide rubber, boron nitride nanosheet and silicon carbide nanowire hybrid filler, a photoinitiator and a silane coupling agent; the component B is prepared from the following raw materials: moisture-cured polyether amine, a boric acid ester bond cross-linking agent and hydrophobic modified graphene oxide. According to the invention, a light-moisture dual-curing mechanism is adopted, ultraviolet irradiation initiates rapid surface curing, and then environmental moisture permeates to complete deep curing. The material provided by the invention has the advantages of rapid curing, excellent self-repairing function, significantly improved underwater adhesion and good thermal conductivity, and provides a new solution for rapid repairing and long-acting protection of underwater structures.

The invention discloses a preparation method and application of a zinc-bromine flow battery positive electrode material, and belongs to the field of zinc-bromine flow batteries. The preparation method comprises the following steps: dissolving aniline and a dithio compound in an acidic ice bath, dropwise adding a peroxy strong oxidant to generate a polyaniline-disulfide bond copolymer, dialyzing, and freeze-drying to obtain powder; then heating soluble silver salt, a reducing agent, a hydrophilic dispersing agent and an organic sulfydryl silane coupling agent to prepare functionalized nano-silver particles; the powder and nano-silver particles are dispersed in N-methyl pyrrolidone for ultrasonic treatment, and dynamic self-repairing coating slurry is prepared; and performing acid pretreatment on the carbon fiber paper, and performing electrochemical deposition on the slurry to prepare the zinc-bromine battery positive electrode material. According to the zinc-bromine battery positive electrode material, the coulombic efficiency and the voltage efficiency of a zinc-bromine flow battery are remarkably improved and the cycle life of the zinc-bromine flow battery is remarkably prolonged through methods of dynamic covalent bonds, nano-silver catalysis, a hierarchical pore structure, carbon fiber pretreatment and the like, and the zinc-bromine flow battery positive electrode material has chemical stability, efficient bromine adsorption capacity and excellent catalytic activity.

The invention discloses a bidirectional reversible conversion method and system between a peptide molecule SMILES and a sequence expression. The core innovation lies in that a new sequence description syntax is defined to retain information of a polypeptide special bond and specific modification of amino acid; a main chain atom index and adjacency traversal topology identification algorithm is adopted, and end group and topology integrated detection and coding are carried out; a residue recognition algorithm for main chain cutting and template library matching is compatible with any standard or non-standard amino acid residues, an extensible end group library / monomer template library and an automatic increment mechanism, and automatic recognition and sequence annotation of S-S disulfide bonds; the invention relates to a high-fidelity assembly algorithm of HELM anchor points and topology aware cyclic peptide processing. The method solves the problems of incapability of supporting a complex polypeptide topological structure, poor reversibility, insufficient expansibility of a monomer library and the like in the prior art, can be widely applied to scenes of quantitative structure-activity relationship model construction, large-scale polypeptide data cleaning and the like, and has remarkable practicability and innovativeness.

The present invention discloses a method for improving the properties of composite meat protein gel based on modified pea protein, which belongs to the technical field of food protein processing. The present invention fully dissolves natural pea protein or pH-shifted modified pea protein to obtain a protein solution; then adds a disulfide bond cleaving agent to the protein solution, dissolves and mixes the solution to obtain modified pea protein. The present invention is based on the disulfide bond cleavage treatment of pea protein to dissociate acidic and basic subunits and expose more internal groups, thereby achieving the improvement of the solubility and functionality of pea protein itself. In addition, both natural pea protein and modified pea protein with disulfide bond cleavage can enhance the structural properties of low-salt meat protein gel under the action of cross-linking enzymes, develop low-salt meat protein gel with good gelation and network structure, and provide solutions and technical support for the quality deterioration of meat products under various circumstances.

The invention discloses a protein-based adsorbent capable of efficiently adsorbing perfluorinated compounds and application of the protein-based adsorbent. The adsorbent is obtained by coating polyethyleneimine in a phase transition aggregate formed by unfolding protein through a disulfide bond reducing agent. The use method of the adsorbent comprises the step of feeding the adsorbent into a solution containing the perfluorinated compound to realize efficient adsorption of the perfluorinated compound. The adsorbent has the advantages of being low in cost, efficient, easy to operate, environmentally friendly, free of secondary pollution, good in biocompatibility and the like, efficient selective adsorption of perfluorinated compounds can be achieved through the adsorbent, the adsorbent can be repeatedly used, and industrial application and popularization are easy.

The invention provides an ELISA (Enzyme Linked Immunosorbent Assay) kit for detecting an anti-MDA5 antibody and a preparation method of the ELISA kit. According to the kit, full-length human MDA5 protein (1025 amino acids) expressed by a cell-free protein expression system under the low-temperature condition of 22 DEG C is adopted as a coating antigen, and a disulfide bond enhancer E6820 is added into the system to promote correct folding of the protein. The kit comprises a microwell plate coated with a full-length MDA5 antigen, an enzyme-labeled anti-human IgG secondary antibody, a standard substance with the concentration range of 1-243 ng / mL, a chromogenic substrate and an optimized confining liquid system. The invention solves the problem of insufficient sensitivity caused by the use of fragment antigens in the prior art, and can be used for early diagnosis and illness monitoring of dermatomyositis-related interstitial lung diseases.

The invention provides a pharmaceutical wastewater treatment process. The pharmaceutical wastewater treatment process comprises the following steps: A1, pretreatment, A2, adsorption treatment, A3, oxidation treatment and A4, filtration treatment. In the step A2, a composite adsorbent comprising the following raw materials: attapulgite, activated carbon, carbon nanotubes, 4-carboxyphenylboronic acid, polyethyleneimine, sodium dithiocarbamate, epoxy resin E-44, deionized water and modified nano zero-valent iron is used, and self-repairing is realized through dynamic chemical bonds such as boric acid ester bonds, imine bonds and thiol-disulfide bonds; the adsorbent can be self-repaired during microscopic damage, so that the service life is prolonged, and relatively high adsorption capacity is kept. In the step A3, a gel microsphere oxidant comprising the following raw materials: hydrogen peroxide, potassium persulfate, copper-iron sulfide, nitrogen-doped carbon quantum dots, sodium alginate powder, sodium polyacrylate and a phosphate buffer solution is used, and efficient degradation is realized through a synergistic mechanism of free radical oxidation, non-free radical oxidation and photocatalysis.

The invention provides a recombinant chicken antibacterial peptide aiming at drug-resistant staphylococcus aureus, and belongs to the technical field of veterinarians. The recombinant chicken antibacterial peptide is expressed through genetic engineering recombinant escherichia coli. Three natural chicken antibacterial peptide active regions are fused, and two disulfide bonds are introduced to stabilize the structure of the recombinant chicken antibacterial peptide and enhance the affinity of the recombinant chicken antibacterial peptide to staphylococcus aureus outer membrane protein. The minimum inhibitory concentration of the recombinant chicken antibacterial peptide to the drug-resistant staphylococcus aureus is obviously lower than that of three natural chicken antibacterial peptides, and the formation of a biomembrane of a USA300 strain of the drug-resistant staphylococcus aureus can be thoroughly inhibited when the minimum inhibitory concentration is 8 mu g / mL. The recombinant chicken antibacterial peptide has a good antibacterial effect on different drug-resistant staphylococcus aureus separated from a chicken house, and can effectively solve the infection problem of the drug-resistant staphylococcus aureus in the chicken house.

The invention belongs to the technical field of antibacterial peptides, and particularly relates to an antibacterial peptide Mh-GC21 as well as a precursor and application thereof. The amino acid sequence of the antibacterial peptide Mh-GC21 provided by the invention is as shown in SEQ ID NO.1, and two cysteines are oxidized to form a pair of intermolecular disulfide bonds; the C tail end of the antibacterial peptide Mh-GC21 is subjected to amidation modification. The antibacterial peptide Mh-GC21 provided by the invention is from microhyla microcarpa, has broad-spectrum antibacterial activity, has relatively good antibacterial and bactericidal effects on standard strains of acinetobacter baumannii, escherichia coli and staphylococcus aureus and clinically sourced drug-resistant strains, and can be used for targeted destruction of cell membranes of bacteria, removal of biological membranes and inhibition of formation of the biological membranes. Moreover, the antibacterial peptide Mh-GC21 has the advantages of good stability, no hemolytic activity and cytotoxicity, and difficulty in inducing strains to generate drug resistance.

The invention discloses a polylipoic acid-based composite sponge wound dressing and a preparation method and application thereof.The preparation method comprises the following steps that polylipoic acid amide with amino is obtained through disulfide bond ring opening polymerization, and the polylipoic acid amide and an aldehyde cross-linking agent are jointly dissolved in ethyl alcohol to form a solution A; carrying out high-speed shearing, dispersing and foaming on the water-soluble polymer, and freeze-drying to form porous sponge B; the porous sponge B is soaked in the solution A to be subjected to a cross-linking reaction, vacuum drying is conducted, and the polylipoic acid-based composite sponge wound dressing is obtained. The preparation method has the characteristics of simple preparation process, safety and no toxicity, the polylipoic acid with excellent oxidation resistance is introduced into the medical sponge material, the preparation method of the polylipoic acid medical porous structure material is obtained, the oxidation resistance and the wet viscosity of the medical sponge material are improved, and the medical sponge material has good application prospects. The application of the polylipoic acid-based porous material in the fields of hemostatic materials and wound dressings is realized.

The invention belongs to the technical field of bioinformatics, and discloses a protein disulfide bond mutation site prediction method and device, equipment and a storage medium, a plurality of candidate residue pairs are extracted by obtaining a prediction structure of a to-be-modified protein, and structural feature information of each candidate residue pair is extracted; comprising an inter-residue distance matrix of two residues, a sequence distance, a relative solvent accessible surface area of each residue, a depth index and a predicted local distance difference test value, inputting a prediction model to obtain a probability value of forming a disulfide bond by each candidate residue pair, determining the candidate residue pair with a probability greater than a specified probability as a disulfide bond mutation site, therefore, the bonding probability of the disulfide bond can be comprehensively predicted by using more comprehensive features, the high dependence of the model on individual traditional features is reduced, the high sensitivity of a traditional method on atomic coordinates and the uncertainty of a prediction result are overcome to a certain extent, and the method has higher robustness and is suitable for popularization and application. The prediction accuracy of the protein disulfide bond mutation site is improved.

The invention discloses a long-acting durable waterproof paint with a self-repairing function and a synthesis method thereof, and relates to the technical field of waterproof paints.The long-acting durable waterproof paint is prepared from self-repairing matrix resin, a bi-component microcapsule self-repairing agent, a fluorine-silicon modified waterproof agent, a nano reinforcing filler and a weather-proof additive; through the synergistic effect of a dynamic disulfide bond and an interpenetrating network, the balance of molecular-level self-repairing and macroscopic mechanical properties is achieved, the efficiency bottleneck of single-component self-repairing is broken through through a two-component microcapsule system, a three-dimensional cross-linked structure of the fluorosilicone modifier endows the super-amphiphobic property, meanwhile, the hydrophobic and oleophobic properties are achieved, and the self-repairing effect is good. In addition, a multi-scale reinforcing system is constructed through the gradient nano filler, so that the crack growth needs to consume higher energy, and finally, the integrity of the microcapsule and the accurate control of the crosslinking degree of the resin are ensured through a specific curing process in the synthesis process, so that the waterproof coating finished product has excellent self-repairing capability, weather resistance and waterproof performance.

The present application relates to a kind of high weather resistance and coating adhesion sunscreen coating and its preparation method, belong to sunscreen coating technical field;The present application uses the modifier with disulfide bond and polymerizable double bond to modify polyacrylate emulsion, significantly improve the flexibility of polyacrylate molecular chain after modification, reduce solidification shrinkage stress and internal stress, improve the coating adhesion of sunscreen coating of hard filler to matrix resin, it can also form stable chemical bonding between polyacrylate resin and titanium dioxide, provide stable stress transfer path, reduce the cracking and warping of coating, in addition, the modifier of the present application has good heat resistance aromatic ring structure, using the modifier of the present application can improve the heat resistance of sunscreen coating without introducing additional modifier.

The present invention provides engineered soluble F proteins of paramyxoviruses, such as respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and human parainfluenza virus (hPIV). These engineered proteins are stabilized by specific modifications in the wild-type soluble F sequence, such as substitutions in the 023 chain and / or the introduction of engineered disulfide bonds in the 0 hairpin in the F1 subunit. The present invention also provides a nanoparticle vaccine comprising an engineered soluble F immunogen displayed on a self-assembled nanoparticle. The invention also provides methods of using such vaccine compositions in a variety of therapeutic applications, e.g., methods for preventing or treating viral infections, such as RSV, MPV, and PIV infections.

The invention relates to the technical field of photovoltaic glass coatings, and discloses an anti-reflection liquid with a self-repairing function, a preparation method of the anti-reflection liquid and an organic-inorganic hybrid coating prepared from the anti-reflection liquid. The polyurethane-silicon dioxide composite resin with a disulfide bond structure is introduced, so that an automatic repairing function of the coating when the coating is damaged by slight scratches or cracks and the like is realized; by adopting an in-situ hybridization strategy, SiO2 particles are uniformly generated and stably dispersed in a polyurethane matrix to form a compact and synergistically enhanced composite network structure, so that excellent optical performance is maintained while functionality is achieved, and the power generation efficiency of a photovoltaic module is favorably improved; by adjusting the hydrophobicity of the surface of the coating, the super-hydrophobic effect is achieved; the preparation method is mild in process conditions.

The invention relates to the field of preparation of lubricating materials, in particular to a preparation method of composite phase change lubricating gel based on temperature-friction force synergistic response. The lubricating gel adopts a sandwich layered structure; the bottom layer is a porous ceramic layer formed by micro-arc oxidation, is filled with a disulfide bond dynamic network polymer and is anchored on a metal substrate; the middle layer comprises a microencapsulated phase change material which is dispersed in a polyurethane network containing dynamic disulfide bonds and is wetted with ionic liquid; the surface layer is an epoxy resin coating rich in boron nitride nanosheets, and a rapid heat conduction channel is constructed. Compared with the prior art, the lubricating state can be automatically adjusted in the friction process without external energy input, and the method has the advantages of being sensitive in multi-field coupling response, capable of achieving automatic antifriction protection, high in extreme working condition adaptability and the like.

The invention discloses a synthesis method of an insulin analogue, which comprises the following steps of: firstly, obtaining A-chain peptide resin by using a solid-phase synthesis method, constructing a disulfide bond between A6 and A11 on a solid phase, and cracking the A-chain peptide resin by using a cracking solution containing a sulfydryl activator to obtain a peptide chain with an activated sulfydryl group and a protected sulfydryl group; then a solid-phase synthesis method is used for obtaining B-chain peptide resin, Lys side chain protecting groups are removed on a solid phase in a fixed-point mode, side chain fatty acid modification is completed, and a peptide chain with an exposed sulfydryl group and a protected sulfydryl group is obtained after cracking is conducted through a cracking solution; and mixing the products in a solution according to a certain proportion to form a first pair of intermolecular disulfide bonds, and constructing and purifying the last pair of disulfide bonds to obtain the insulin analogue. The method disclosed by the invention has the advantages of convenience in synthesis, low cost, simple process and the like, can be used for research on amino acid mutation of insulin compounds, and has important practical significance on development of insulin drugs.

The invention discloses a super-tough temperature-resistant self-repairing copolymer based on SBS acrylate dynamic synergistic reinforcement and a preparation method thereof, and belongs to the technical field of self-repairing materials in compositions of high-molecular compounds. The copolymer comprises SBS, an acrylate monomer, a dynamic bond functional monomer, an initiator, a cross-linking agent, a nano reinforcing agent and a temperature-resistant modifier, wherein the dynamic bond functional monomer comprises at least one of acryloyloxyethyl disulfide, acrylamide acryloyloxyethyl disulfide or anthracene methyl acrylate. The molecular structure of the dynamic bond functional monomer contains a carbon-carbon double bond and a disulfide bond, in the free radical polymerization reaction initiated by the initiator, the carbon-carbon double bond is opened and is subjected to a copolymerization reaction with an SBS chain segment or an acrylate chain segment, so that the disulfide bond enters the polymer chain segment, the dynamic disulfide bond can be reversibly broken and recombined at high temperature, and the dynamic bond functional monomer is obtained. The high-temperature viscoelasticity is maintained, the material is endowed with self-repairing capability, and the problem that the viscoelasticity of the material in the prior art is sharply reduced at high temperature (gt; 120 DEG C) is solved.

The invention belongs to the technical field of epoxy resin, and particularly relates to a self-repairing epoxy insulating material as well as a preparation method and application thereof. The invention relates to a self-repairing epoxy insulating material, which is prepared from the following raw materials: an epoxy resin matrix, a heat-conducting filler dispersed in the epoxy resin matrix, a cross-linking agent and a curing agent, wherein the heat-conducting filler is subjected to surface modification through an amphiphilic polymer, and a gradient compatibility interface layer is formed on the surface of a particle and is used for improving the interface compatibility between the heat-conducting filler and the epoxy resin matrix and reducing the interface thermal resistance; the cross-linking agent comprises reversible covalent bonds of disulfide bonds and / or imide bonds, a dynamic cross-linked network is formed in the epoxy resin matrix, and the dynamic cross-linked network can perform reversible fracture and recombination of chemical bonds through external stimulation, so that the epoxy insulating material has self-repairing capability.

The invention belongs to the technical field of functional polymer composite caulking materials, and relates to a polyurethane caulking material based on shape memory assisted self-repairing and a preparation method thereof. The polyurethane caulking material is prepared from the following raw materials in parts by mass: a component A and a component B, the component A is prepared from 20 to 30 parts of isocyanate and 100 parts of polyhydric alcohol; and the component B comprises 1-13 parts of a sulfur-containing chain extender for providing dynamic disulfide bonds, 1-5.4 parts of a common chain extender, 0-30 parts of a plasticizer, 0.5-1.5 parts of a water removal agent and 20-40 parts of a solvent. During preparation, the component B and the component A are mixed at the temperature of 40-60 DEG C, defoamed at the temperature of 30-50 DEG C and then injected into a mold, and the polyurethane caulking material based on shape memory assisted self-repairing is obtained after curing. The problem that an existing polyurethane caulking material lacks self-repairing capacity after cracks are generated is solved.

The invention discloses an amyloid-like protein mediated long-acting metal organic framework antifouling agent as well as a preparation method and application thereof. Belongs to the field of marine antifouling material preparation. The anti-fouling agent is based on MOF with an anti-fouling function, and amyloid-like protein is self-assembled on the surface of the MOF to form a compact protective shell layer. According to the preparation method, metal ions and organic ligands react and are connected through coordinate bonds to form an MOF structure, and MOF particles are obtained through centrifugation, collection, precipitation, washing and drying; under the action of a water-soluble organic reducing substance, the protein completely opens a disulfide bond to form an unfolded protein chain, and the protein chain is self-assembled to obtain an amyloid-like protein solution; and placing the MOF particles in an amyloid-like protein solution, and carrying out simple one-step incubation to obtain the amyloid-like protein mediated long-acting metal organic framework antifouling agent. The antifouling agent is prepared by adopting a novel green, high-stability, rapid and efficient mild modification method, and has the advantages of stability, durability, universality and high efficiency.

The invention discloses an RSV pre-F tripolymer protein combination and application thereof in preparation of bivalent RSV vaccines, and relates to the technical field of human vaccines. The vaccine is prepared by mixing an RSV-A subtype pre-F tripolymer protein and an RSV-B subtype pre-F tripolymer protein in equal mass, and matching with an aluminum hydroxide adjuvant with the concentration of 0.35 mg / 0.5 mL. A p27 fragment and a C-terminal esterification region of each of the two F proteins are deleted, the two F proteins are connected with F2 / F1 through GSGSGS, inter-chain disulfide bonds are introduced to S146C / N460C and A149C / Y458C sites respectively, intra-chain disulfide bonds are introduced to S155C / S290C sites respectively, and stable pre-F trimers are spontaneously assembled after secretion expression of CHO cells; the vaccine does not need to be freeze-dried, still keeps high purity and neutralizing epitope integrity after being stored at 37 DEG C for 28 days, can obviously induce neutralizing antibody and T cell immunity, and can be used for preventing various RSV-A / B infections.

The invention relates to room-temperature self-repairing polyurethane with quadruple hydrogen bonds / disulfide bonds and a preparation method of the room-temperature self-repairing polyurethane, and the prepared polyurethane is a thermoplastic polymer and shows a dynamic cross-linked structure. The polyurethane is prepared by adopting a step-by-step polymerization method in the presence of two chain extenders containing different dynamic bonds, the prepared polyurethane has good mechanical properties, self-repairing of cracks can be realized in a room temperature environment, and the method is simple and easy to industrialize. The polyurethane has important application value in the industries of flexible electronics, medical instruments, long-acting protection and the like.

The application provides a reverse osmosis membrane and a preparation method and application thereof. The preparation method comprises the following steps: (1) polymeric reaction of a polyamine and a polyacyl chloride on a support membrane to form a polyamide layer on the support membrane; and (2) reaction of the polyamide layer prepared in step (1) and a benzene series A to obtain the reverse osmosis membrane; the benzene series A is a benzene series containing an amino group, an antibacterial group, a disulfide bond and a phenoxy group. The reverse osmosis membrane provided by the application has high flux and high desalination rate, and excellent oxidation resistance, antibacterial property and acid and alkali resistance.