51results about How to "Solve degradation" patented technology

The invention discloses a recombinant human III-type collagen and a pichia pastoris recombinant expression system thereof. According to the invention, a Gly-X-Y structural peptide containing valine, phenylalanine, leucine, methionine and alanine in a part of peptide fragments of human III-type collagen is replaced with a Gly-X-Y structural peptide which is high in use frequency and does not contain the amino acid, and a gene sequence for encoding the peptide fragments is obtained according to the peptide fragments after the replacement. And then gene expression vectors for tandem expression ofpeptide fragments with different repeat numbers are constructed and transformed into pichia pastoris host bacteria, and a strain for high expression of the recombinant human III-type collagen is obtained through screening. Through artificial design optimization of a protein structure, the problem that natural collagen is degraded in fermentation is effectively solved, and an expression product has high stability and good biocompatibility and can be used for large-scale production.

The invention relates to a vertical type animal gastrointestinal bionic digester, which comprises a motor, a connecting shaft sleeve, a heightening transmission rod, a stirring rod and a simulated digestive tract, wherein the connecting shaft sleeve is sleeved on an output shaft of the motor and synchronously rotates along with the motor, and the top end of the heightening transmission rod is fixedly sleeved in a sliding chute below the connecting shaft sleeve by a screw rod, so that the heightening transmission rod can move up and down in the connecting shaft sleeve; a locking nut is arranged on the heightening transmission rod and is used for adjusting the locking degree of the heightening transmission rod and the stirring rod, and the simulated digestive tract is a double-layer hollow vertical glass tube; the stirring rod is arranged in an accommodating cavity of the simulated digestive tract, and the top end of the stirring rod penetrates through a sealing plug at the top of the simulated digestive tract and is connected with the bottom end of the heightening transmission rod. The vertical type animal gastrointestinal bionic digester provided by the invention has the advantages of simple structure, convenience in use, avoidance of leakage of a bionic digestion reaction liquid, high accuracy and good repeatability of digestion simulation, and small errors; the degradation difficulty of cellulose on a dialysis bag in the existing simulated digestive tract in a bionic digestion reaction is effectively solved.

The invention belongs to the field of biodegradable plastics, and discloses a method for preparing attapulgite-based biodegradable plastics from a natural attapulgite-loaded biopolymer material and a photocatalytic material. Natural attapulgite is subjected to functionalization treatment to serve as a carrier, a biological polymer material and a photocatalytic material are adsorbed through a physical/chemical method, modified attapulgite composite powder is prepared, the modified attapulgite composite powder and biodegradable plastic powder are blended to prepare a modified master batch, and the attapulgite-based biodegradable plastic which is low in cost, good in mechanical property and high in degradation rate is prepared through processing and forming. The attapulgite-based biodegradable plastic prepared by the method has the characteristics of good mechanical property, low cost, high biological decomposition rate and the like, can be applied to replace traditional non-degradable plastic, and provides a new way for solving the problem of white pollution.

The invention discloses a method for extracting total RNA (Ribonucleic Acid) of grapholita molesta adult antennae. The method comprises the following steps of: freezing grapholita molesta adults for coma under a low temperature condition, shearing a plurality of antennae by using small medical scissors and forceps, immediately soaking the antennae in a 1.5ml centrifugal tube in liquid nitrogen, taking the centrifugal tube out of liquid ammonia, immediately adding a small amount of RNA extraction liquid, fully homogenizing the extraction liquid by using a homogenizer, adding enough total RNA extraction liquid, blowing for a few times by use of a pipettor, transferring to the other new centrifugal tube, performing chloroform extraction according to a total RNA extraction method, and performing isopropanol and ethanol precipitation and separation, thus obtaining high-purity total RNA. The method is simple and convenient, and can be used for solving the problem about degradation of the RNA in the extraction process, so that the high-quality total RNA is obtained.

The invention discloses a recombinant III-type humanized collagen, a nucleic acid, a carrier and an implant, and relates to the technical field of biological genes. Sequence peptide fragments 549-560aa, 597-613aa, 881-902aa and 648-662aa which are obtained by screening a natural human III type collagen alpha1 chain for a long time and have good stability are selected, the four peptide fragments are spliced in sequence to form monomers, and then tandem expression is performed on the monomers. Through fermentation and purification, the obtained recombinant III-type humanized collagen is high in stability, the problem of degradation of the recombinant III-type humanized collagen in the clinical use process is effectively solved, and the recombinant III-type humanized collagen can be prepared into a liquid preparation for preservation and use.