Abstract: The present invention provides an improved method and system for denoising high-frequency ultrasound based on a multipath matching pursuit algorithm. The method includes: acquiring a high-frequency ultrasound detection signal of a to-be-tested sample; constructing a discrete overcomplete dictionary according to the high-frequency ultrasound detection signal, and training the discrete overcomplete dictionary; reconstructing the high-frequency ultrasound detection signal by using a trained dictionary and using a multipath matching pursuit algorithm, and obtaining a global optimal atom; performing interpolation on the global optimal atom, and constructing a consecutive atomic library; and reconstructing the high-frequency ultrasound detection signal in the consecutive atomic library according to a parameter of the global optimal atom, to complete signal denoising.

Abstract: The present invention provides exosomes derived from human nasal mucosa mesenchymal stem cells, their preparation method, and applications. The human nasal mucosa mesenchymal stem cells can be derived from the patients themselves, ensuring an adequate cell supply and strong plasticity. Research has found that as seed cells for extracting extracellular vesicles, these cells have been proven to promote the proliferation and differentiation of endogenous neural stem cells, bridge injury sites, and facilitate spinal cord injury repair. The effects are significant, making it convenient for widespread application and promotion.

Abstract: The invention provides a Saccharomyces cerevisiae strain for producing a human milk lipid substitute. By integrating a heterologous lysophosphatidic acid acyltransferase into Saccharomyces cerevisiae and knocking out its own natural lysophosphatidic acid acyltransferase, the content of palmitic acid (C16:0) at Sn-2 position of triacylglycerol produced by Saccharomyces cerevisiae is increased, to synthesize a human milk lipid substitute. On this basis, a metabolic pathway related gene is knocked out, to further increase the content of human milk lipid substitute in the product. In the present invention, a human milk lipid substitute is de novo synthesized by Saccharomyces cerevisiae for the first time, in which the total fatty acid is 15% or more, and the relative content of C16:0 at Sn-2 position reaches about 60%.

Abstract: Non-natural sugars modified with a bioorthogonal reactive group are added into a culture medium of immune cells such as NK cells to obtain immune cells modified with the bioorthogonal reactive group; and then, under a physiological condition, a targeting ligand, for example, a nanobody, is modified to a surface of each of the immune cells through a bioorthogonal reaction, wherein the targeting ligand has one terminal with a bioorthogonal reactive pairing group which is capable of being matched and connected with the bioorthogonal reactive group to generate a connecting reaction, connection is implemented by a transpeptidase SrtA-mediated chemoenzymatic method. The targeting ligand highly specifically recognizes and binds to a highly expressed receptor on the surface of tumor cells. The immune cell modified with the targeting ligand can specifically bind in a targeted way to the tumor cells, therefore generating cytokines, killing and damaging tumor cells.

Abstract: The invention provides a fusion protein for treating metabolic diseases, and a preparation method and use thereof. The fusion protein has a general formula of R1-L-R2 or R2-L-R1, wherein R1 is FGF21 protein, an FGF21 protein analog, or a similar peptide with the biological function of FGF21 protein; R2 is GIP, mutant GIP or a similar peptide with the biological function of GIP; and L is a linker peptide.

Abstract: The invention provides an oligosaccharide debranching enzyme mutant and use thereof in a glucose mother liquor. The mutant is obtained by mutating valine at position 219 in SEQ ID NO: 1 into alanine. According to oligosaccharide debranching enzyme mutant V219A, a primary mother liquor, a secondary mother liquor, or a tail liquid after chromatographic separation is used as a substrate, the percentage contents of glucose in the products are 99.21% (primary mother liquor), 98.89% (secondary mother liquor) and 97.97% (tail liquid after chromatographic separation) respectively, which are 2.86%, 8.64%, and 28.67% higher than that of glucose obtained with the wild-type oligosaccharide debranching enzyme. Therefore, the mutant V219A obviously improves the percentage content of glucose in the glucose mother liquor, and the scope of application of the mother liquor can be expanded by the high product purity and substrate conversion rate, so the mutant V219A has higher industrial application value.

Abstract: A dark-colored system photopolymerization composition, comprising: 20-80 phr of photopolymerizable prepolymer, 5-60 phr of photopolymerizable monomer, 0.2-8 phr of photoinitiator, and 0.1-5 phr of melanin, 0.05-5 phr of upconversion materials. The composition can construct photopolymerization under near-infrared irradiation. The dark pigment can avoid the strong absorption of near-infrared light, and the upconversion material can absorb near-infrared light with good penetrating ability and emit ultraviolet or visible light to induce the decomposition of free radicals or ionic photoinitiators in the composition. Then produced active species realize the photopolymerization of dark-colored compositions. The invention increases the depth of photopolymerization of dark-colored compositions and improves the mechanical properties of the polymer, that will broaden application fields of photopolymerization materials.

Abstract: Disclosed is a hybridoma cell strain that secretes anti-dinitolmide monoclonal antibodies applicable to the field of food safety immunoassay methods. The hybridoma cell strain DAS3H10 that secretes anti-dinitolmide monoclonal antibodies has been deposited in Comprehensive Microbiology Center of China Microbial Culture Collection Management Committee (CGMCC), addressed in No. 1 Hospital No. 3 Institute of Microbiology of the Chinese Academy of Sciences, North Chenxi Road, Beijing Chaoyang District in Beijing. It is classified as a monoclonal cell strain. The deposit date is Nov. 28, 2019, and the deposit number is MCCC No. 19165. The monoclonal antibody secreted by the hybridoma cell strain DAS3H10 has a good affinity and high sensitivity to dinitolmide. Because of IC50 to dinitolmide up to 9.01 ng/mL, the monoclonal antibody could be used to prepare dinitolmide immunoassay kits and colloidal gold test strips, and can further provide a powerful means for detecting dinitolmide in animal-derived foods.

Abstract: The present invention discloses a RamA transcription factor mutant for promoting the production of N-acetylglucosamine and use thereof. The mutant is obtained by mutating lysine at position 90 to asparagine and serine at position 92 to lysine in a parent having an amino acid sequence as shown in SEQ ID NO: 2. The present invention provides a genetically engineered strain that overexpresses the RamA transcription factor mutant and increases the production of N-acetylglucosamine. By overexpressing the transcription factor RamA that is involved in the regulation of carbon metabolism, the extracellular accumulation of N-acetylglucosamine is increased, with a maximum concentration reaching 31.5 g/L, which lays a foundation for further metabolic engineering of Corynebacterium glutamicum to produce glucosamine. The method for constructing recombinant Corynebacterium glutamicum of the invention is simple, and convenient in use, and thus has good application prospects.

Abstract: A method for preparing a sustained-release antibacterial film includes: (1) mixing a cyclodextrin metal-organic framework (CD-MOF) material with a silver nitrate short-chain alcohol solution to prepare an intermediate material A; (2) mixing the intermediate material A with a caffeic acid short-chain alcohol solution to prepare an intermediate material B; (3) dispersing the intermediate material B in a solvent, adding a polydimethylsiloxane main agent and a PDMS auxiliary agent in sequence, and mixing well by stirring to obtain a casting solution; and (4) coating the casting solution on a film support material, conducting vacuum drying, and peeling off a film from the film support material to obtain the sustained-release antibacterial film. A mixed matrix-based film material in which the CD-MOF and the PDMS are physically blended is prepared based on CD-MOF and PDMS for the first time, and may be used in application researches of food, environment and other fields.

Abstract: The invention provides a method for constructing a target prediction model in a multicenter small sample scenario and a prediction method. In combination with the idea of transfer learning, a training set of a new node is predicted by directly using knowledge of a trained node, and a prediction error sample is used to reflect a difference between the new node and the trained node. The difference is used as supplementary knowledge. Model knowledge of the new node is quickly acquired, to avoid training of a new node from scratch each time. Finally, parallel integration of incremental subclassifiers is implemented by using a ridge regression method, so that the deployment time and costs are greatly reduced. The generalization of models is ensured through sharing of historical knowledge and a knowledge discarding mechanism, good classification effect can also be achieved for a node with a small sample size.

Abstract: A hybridoma cell line of secreting cyproheptadine monoclonal antibodies with a preservation number of CGMCC No. 14699 belongs to the field of food safety immunological detection. BALB/c mice are immunized through one time immunization with complete freund's adjuvant, three times of booster immunization with incomplete freund's adjuvant and one time of rush immunization with cyproheptadine complete antigen without adjuvant; the spleen cells from BALB/C mice immunized with high potency and low value of IC50 are fused with murine myeloma cells; and then the hybridoma cell line is obtained through indirect competitive ELISA screening and three sub-clones. The monoclonal antibody secreted by this cell line has good specificity and detection sensitivity to cyproheptadine (value of IC50 is 0.37 ng/ml), being suitable for detection of cyproheptadine in food.

Abstract: The present invention provides a method for promoting N-acetylglucosamine synthesis by using the GlcN6P responsive element. In the present invention, Bacillus subtilis BSGNY-Pveg-glmS-P43-GNA1 is used as a starting strain, in which a CRISPRi system regulated by GlcN6P responsive element is integrated into the genome to dynamically weaken the N-acetylglucosamine synthesis competitive pathway; a GlcN6P responsive promoter is used to regulate the expression of GNA1 on the plasmid to dynamically regulate the N-acetylglucosamine synthesis pathway; and the key gene alsSD involved in the acetoin synthesis pathway is knocked out. During fed-batch fermentation with this strain in a 15 L fermenter, the production of N-acetylglucosamine reaches 131.6 g/L and no by-product acetoin is accumulated, which lays a foundation for the production of GlcNAc by industrial fermentation.

Abstract: The disclosure discloses a method for producing maltodextrin with a single polymerization degree by multienzyme coupling, and belongs to the technical field of biology. The disclosure provides a method for producing non-reducing maltodextrin with a uniform and low polymerization degree. After a reaction is preformed for 2-6 hours by using the method of the disclosure, the content of 4-O-?-maltohexaosyl ?-D-glucoside in a reaction solution can be as high as 57.2% to 77.3%, accounting for 50% to 90% of the total amount of maltodextrin in the reaction solution. In maltodextrin prepared by using the method of the disclosure, non-reducing maltodextrin with low polymerization degree only includes 4-O-?-maltohexaosyl ?-D-glucoside, and the content of non-reducing maltodextrin with low polymerization degree can be 50% to 90% of the total amount of maltodextrin.

Abstract: The invention relates to an ink based on near-infrared light polymerization. The method and technology of direct writing three-dimensional printing belong to the field of material processing technology area. The method is: direct writing nozzles move in three-dimensional space or stationery, the ink is squeezed out of the direct writing nozzle, receiving the near-infrared light irradiation, after curing, complete the three-dimensional object forming and curing. The solidifying time t does not exceed the ratio of near-infrared light diameter dl and the ink extrusion speed vi, that is, t?dl/vi. Since near-infrared light has a better medium mass penetration, can penetrate the structure during molding to promote both internal and external to a higher degree of curing, so as to achieve cross-scale structure 3D printing, and the method provided by the present invention accurately controls solidifying process of the ink and therefore achieve the DIW array 3D structure real-time curing.

Abstract: The present invention provides a nucleic acid aptamer specifically recognizing ?-lactoglobulin and use thereof. The nucleic acid aptamer has a sequence as shown in SEQ ID NO:1, a sequence having 60% or higher homology to the sequence as shown in SEQ ID NO:1 and specifically recognizing ?-lactoglobulin, or a sequence derived from the sequence as shown in SEQ ID NO:1 and specifically recognizing ?-lactoglobulin. The nucleic acid aptamer specifically binds to the allergen ?-lactoglobulin in cow milk and dairy products, thereby providing a new tool for the high-sensitivity and low-cost detection of the allergen ?-lactoglobulin.

Abstract: The present application belongs to the technical field of research and development of fermented beverages, and a method for preparing Cordyceps militaris ferment by two-stage fermentation and complex enzymatic hydrolysis is provided. The present application involves preparation of a Cordyceps militaris powder and a Cordyceps militaris slurry, preparation of a Cordyceps militaris fermentation substrate, lactic acid bacteria fermentation in combination with complex enzymatic hydrolysis, and yeast fermentation, followed by centrifugation, filtration, formulation, sterilization, and filling to obtain a product. By employing lactic acid bacteria fermentation in combination with complex enzymatic hydrolysis, and secondary fermentation by yeast, the present application can quickly finish a whole fermentation process in 2 to 3 days.

Abstract: The present invention discloses a cyclohexenecarboxylate ester hydrolase, and a mutant, a coding gene, an expression vector, recombinant bacterium and use thereof. The cyclohexenecarboxylate ester hydrolase AcEst1 and its mutant of the present invention have the function of enantioselectively resolving methyl 3-cyclohexene-1-carboxylate with high efficiency to prepare optically active (S)-3-cyclohexene-1-carboxylic acid. When the substrate concentration is as high as 2000 mM (about 280 g/L), the optical purity of the product is higher than 99%, and the substrate/catalyst is as high as 3500 g/g. As compared with other preparation methods, the product prepared by the method of the present invention has high concentration and high optical purity, the catalytic efficiency is high, the reaction conditions are mild. Furthermore, the method is environmentally friendly, simple in operation and easy for industrial scale-up, thus has a good prospect of application in industry.

Abstract: The present invention discloses a visual bionic digestive system for a human gastrointestinal tract model, and belongs to the field of bionic digestive systems.

Abstract: Disclosed is an ultrasonic composite acidic water extraction method for a Cordyceps polysaccharide and cordycepin in Cordyceps militaris, which falls within the technical field of food processing. The method comprises: picking, washing, drying, pulverizing and degreasing Cordyceps militaris fruiting bodies to obtain a Cordyceps militaris dry powder; then immersing same in a prepared diluted hydrochloric acid solution to perform three cycles of ultra-low temperature freezing and microwave defrosting, and at the same time using low-frequency ultrasonic waves to carry out assisted stirring and extraction; then subjecting an extract to evaporation and concentration treatments; and finally, performing freeze-drying on the extract to collect a dry powder of a water extraction product.