25 results about "Gradient centrifugation" patented technology

This invention discloses a method for isolating and preparing Chlorella exovesicles. Specifically, Chlorella, conventionally cultured to the early logarithmic growth phase, is induced to develop in a nitrogen-limited medium. The culture medium is then concentrated using a tangential flow filtration system. Finally, the concentrate is subjected to density gradient centrifugation with iodixanol. After centrifugation, components within the density range of 1.10–1.12 g / mL are collected to obtain the Chlorella exovesicle product. This invention achieves concentrated and precise collection of Chlorella exovesicles by regulating membrane lipids during the early induction culture of Chlorella, combined with TFF concentration and density gradient centrifugation. This method effectively eliminates impurities, achieving a recovery rate of over 60% and a purity of 2.56 × 10⁻⁶. 10 The particle / μg method provides an efficient, controllable, and scalable solution for the industrial-scale separation and preparation of microalgal exovesicles.

This invention relates to the field of hydraulic oil purification technology, specifically a method for online hydraulic oil purification and performance regeneration based on centrifugal force field control. The method includes: online acquisition of real-time operating parameters of the hydraulic system and hydraulic oil state data; prediction of contaminant concentration distribution and deteriorated component content; dynamic calculation of the centrifugal force field intensity distribution curve using a state inversion algorithm; and control of the centrifugal device to form a gradient-changing directional centrifugal force field. Based on gradient centrifugation, the method removes solid particles, free water, and colloidal substances step-by-step. Simultaneously, it fine-tunes the local intensity of the centrifugal force field according to the deteriorated component content, selectively removing deteriorated oil molecular components while retaining intact base oil and effective additives. This method enables precise online grading and purification of hydraulic oil, adapts to the real-time state of the oil, improves impurity removal, simultaneously completes oil performance regeneration, and optimizes the quality of purification and regeneration treatment.

This invention discloses a Polygonatum sibiricum vesicle preparation for treating premature ovarian failure, its preparation method, and its application. The preparation method includes: cleaning Polygonatum sibiricum, juicing, filtering to remove residue, and collecting the juice; subjecting the juice to gradient centrifugation to remove residual plant tissue, plant cells, and plant cell debris; then using an extraction reagent for stepwise precipitation, collecting the precipitate, and resuspending it to obtain the final product. The Polygonatum sibiricum vesicle preparation prepared by this invention can be efficiently taken up by ovarian granulosa cells. It effectively treats premature ovarian failure by activating the Nrf2 signaling pathway, upregulating antioxidant enzyme expression, scavenging reactive oxygen species, restoring mitochondrial membrane potential, inhibiting apoptosis, and restoring the expression levels of estrogen, follicle-stimulating hormone, and anti-Müllerian hormone. The preparation method of this invention is standardized, biocompatible, and safe, and has broad clinical application prospects.

The application relates to a method for separating and primary culturing of monopterus albus liver cells. The method comprises the following steps: obtaining monopterus albus liver tissue, perfusing the liver tissue with HBSS buffer solution without calcium and magnesium until blood is completely drained; removing the capsule, blood clots and connective tissue after rinsing, and cutting the liver tissue; sequentially using 0.02% EDTA solution, 0.25% trypsin solution and 50 U / mL collagenase IV working solution to perform three-step digestion treatment on the liver tissue fragments; obtaining a cell suspension by blowing and filtering after the digestion is completed, and then performing gradient centrifugal purification of the cells at rotating speeds of 600 rpm, 250 rpm and 80 rpm in sequence; and finally resuspending the cells in DMEM / F12 culture medium containing 10% FBS and inoculating and culturing the cells. The monopterus albus primary liver cells obtained by the method have the advantages of large quantity, high activity and high purity, and provide a reliable in-vitro model for monopterus albus related research.

This invention relates to a method for identifying functional microorganisms in a mixed nutrient denitrification system of iron autotrophic and heterotrophic components, belonging to the field of wastewater biological treatment technology. The invention first constructs a mixed nutrient denitrification system, and then conducts microenvironmental culture by setting up a control group, an autotrophic labeled group, and a heterotrophic labeled group. Separation is then performed using cesium chloride density gradient centrifugation. 13 C-labeled heavy-chain DNA was used to determine the heavy-chain position using real-time quantitative PCR, followed by 16S rRNA gene sequencing to accurately identify iron-autotrophic and heterotrophic functional microorganisms. Based on the identification results, the response patterns and interaction mechanisms of different trophic microorganisms were analyzed by regulating the COD / TN ratio of the system and constructing a molecular ecological network. This invention achieves accurate identification and interaction analysis of functional microorganisms in complex mixed trophic systems, providing a reliable technical means for optimizing wastewater denitrification processes.

This invention relates to plant exosomes derived from depleted blood flow, their preparation method, and applications. The preparation method includes: mixing depleted blood flow tissue with a buffer solution and homogenizing the mixture to obtain a homogenate; enzymatically hydrolyzing the homogenate before multi-stage gradient centrifugation to promote exosome release, obtaining an enzymatic hydrolysate; performing multi-stage gradient centrifugation on the enzymatic hydrolysate to obtain a supernatant; and filtering the supernatant to obtain depleted blood flow exosomes. Compared with existing technologies, the preparation process of this invention is simple and safe, and the resulting product has good integrity and biological activity, possessing antioxidant, anti-inflammatory, antibacterial, cell viability protection, and UV and blue light protection effects. Depleted blood flow exosomes can be used as functional active ingredients in cosmetics or as carriers of active substances to improve their stability, solubility, and skin absorption efficiency. This invention not only expands the application pathways of depleted blood flow resources but also provides new technical means and application value for the development of plant-derived exosomes in functional cosmetics and topical preparations.

This invention discloses a high-BNIP3-loaded exosome, its preparation method, and its applications, relating to the field of biomedical engineering technology. The high-BNIP3-loaded exosomes are obtained by pre-treating human bone marrow mesenchymal stem cells transfected with a recombinant expression vector carrying the BNIP3 gene, followed by 24 hours of hypoxia at 1% oxygen concentration. The exosomes have a particle size of 40-130 nm and highly express BNIP3 and exosome markers HSP70, CD63, and TSG101. The preparation method includes constructing a pcDNA3.1-BNIP3 recombinant vector, transfecting and screening stable-expressing engineered cells, hypoxia pre-treatment, and purification by gradient centrifugation combined with ultracentrifugation. This invention achieves efficient loading and targeted delivery of BNIP3 through a synergistic strategy of genetic engineering and microenvironment simulation, significantly improving the endocytosis efficiency of nucleus pulposus cells, activating mitophagy, restoring mitochondrial function, and promoting extracellular matrix synthesis. It can be used to prepare drugs for treating intervertebral disc degeneration and has excellent clinical application prospects.

This invention discloses the application of yam exosomes in the preparation of drugs for the prevention of colitis, belonging to the field of plant exosome technology. This invention employs a polyethylene glycol (PEG) precipitation method combined with ultracentrifugation to extract yam exosomes. Compared with the traditional sucrose density gradient centrifugation method, this method has a simpler operation process and can efficiently obtain yam exosomes with uniform morphology and intact structure. The obtained yam exosomes can not only prevent colitis but also effectively improve loperamide-induced constipation symptoms.

This invention relates to the fields of biomedicine and ophthalmic drug technology, specifically to an herbal exosome composition for eye care and treatment and its preparation method. The composition comprises a synergistic combination of herbal exosomes and mesenchymal stem cell exosomes, and also includes a nano-sustained-release carrier system. The herbal exosomes are extracted from the traditional herb licorice using gradient centrifugation combined with size exclusion chromatography, and the active herbal components astragaloside and quercetin are loaded onto the exosomes using electroporation to enhance their pharmacological activity. The nano-sustained-release carrier system has a biphasic sustained-release structure: the inner phase is a phospholipid complex carrying herbal exosomes and mesenchymal stem cell exosomes, and the outer phase is a thermosensitive hydrogel; it is liquid at room temperature, but rapidly transforms into a gel state after being instilled onto the ocular surface, significantly prolonging the drug's residence time on the ocular surface, improving bioavailability, and endowing it with targeted sustained-release capability against ocular surface tissues.

The application relates to the technical field of carbon nanotubes, and particularly discloses a carbon nanotube purification method. The carbon nanotube purification method comprises the following steps: (1) weighing carbon nanotube crude products and various raw materials; (2) adding the carbon nanotube crude products and a surfactant into deionized water to perform ultrasonic dispersion, so as to obtain a dispersion liquid; (3) performing gradient centrifugation on the dispersion liquid, and taking upper suspension; (4) mixing hydrochloric acid and nitric acid with the suspension to treat the carbon nanotubes; (5) treating the carbon nanotubes with dilute acid, mildly oxidizing the carbon nanotubes through a low-concentration hydrogen peroxide solution, and then adsorbing magnetic impurities in a magnetic field; (6) performing cross-flow filtration through a polycarbonate microfiltration membrane, and collecting the treated carbon nanotubes; and (7) performing inert gas annealing on the treated carbon nanotubes, and performing freeze drying, so as to obtain purified carbon nanotubes. The purification method can efficiently remove metal catalysts, amorphous carbon and graphite impurities, and meanwhile, the tube wall integrity of the carbon nanotubes is maintained.

FIELD: neurology; laboratory diagnostics.SUBSTANCE: used for the differential diagnosis of Parkinson's disease not associated with mutations in the GBA1 gene, and multiple system atrophy. The patient's peripheral venous blood is collected, from which mononuclear cells are isolated by gradient centrifugation, followed by their differentiation into a primary culture of macrophages in the presence of the macrophage colony-stimulating growth factor M-CSF to ensure proliferation and differentiation of monocytes into mature macrophages. The obtained blood macrophage cells are applied to 903 filter cards at a concentration of 2×106 cells / ml. Whatman 903 Sample Collection Cards can be used as 903 filter cards. The activity of lysosomal enzymes is determined: glucocerebrosidase GCase, alpha-galactosidase GLA, acid sphingomyelinase ASMase, galactosylceramidase GALC by high-performance liquid chromatography in combination with tandem mass spectrometry. The value of the canonical linear discriminant function CLDF is calculated using the stated formula. If the value of CLDF is ≥ 43.44, the patient is diagnosed with multiple system atrophy. If the value of CLDF is < 43.44, Parkinson's disease is diagnosed in patients who do not have a mutation in the GBA1 gene.EFFECT: method enables reliable and accurate differential diagnosis of Parkinson's disease and multiple system atrophy by assessing the activity of lysosomal enzymes.2 cl, 2 dwg, 2 ex

The application discloses a living extraction method of citrus Huanglongbing bacteria, relates to the technical field of plant pathogenic bacteria extraction, and solves the problem that the prior art cannot guarantee that the citrus Huanglongbing bacteria have complete biological activity and high purity at the same time. The method comprises four core steps of pretreatment of Rutaceae plant samples, extraction of bacterial liquid, initial enrichment of the bacterial liquid and re-enrichment of the bacterial liquid in sequence, the whole extraction process is carried out in a low-temperature environment, plant tissues infected with pathogenic bacteria are broken by freezing and grinding, and step-by-step extraction and enrichment of the citrus Huanglongbing bacteria are realized by combining step-by-step differential centrifugation and sucrose density gradient centrifugation. The method can effectively retain the complete biological activity of the citrus Huanglongbing bacteria, significantly improve the purity of the bacterial liquid, and the prepared bacterial liquid can be used for infection of healthy Rutaceae plants and microinjection transfection of citrus psyllids, the method is simple in operation and good in repeatability, and provides stable and reliable experimental materials for the research on the pathogenic mechanism, transmission rule and prevention and control technology of the citrus Huanglongbing disease.

This invention discloses a method and product for manufacturing LEDs with anti-sulfurization and low light decay, comprising the following steps: S1, preparation of composite ceramic powder; S2, slurry preparation: mixing composite ceramic powder with organosilicon resin in a certain proportion, then adding polyethylene glycol and fumed silica in a certain proportion, adjusting the slurry viscosity to 500-800 mPa·s to obtain a slurry; S3, pre-orientation treatment: immersing the LED bracket in the above slurry, applying 18-22 kHz ultrasonic vibration and 1-3 m / s directional airflow, and treating for 5-8 min; S4, gradient centrifugation sedimentation: fixing the LED bracket in a variable frequency centrifuge, with the LED bracket at an angle of 15-30° to the centrifugal force direction, and centrifuging at a five-stage gradient speed; S5, curing and sintering. This invention achieves a synergistic improvement in heat dissipation and anti-sulfurization through optimization of the composite ceramic powder material formulation and process innovation.

The application discloses a glass wool raw material added with a fluxing agent and a glass wool preparation method, and belongs to the technical field of glass wool preparation. The glass wool raw material of the application adopts quartz sand, feldspar, borax, soda ash, potassium nitrate, dolomite, calcite and recycled glass clinker as raw materials, innovatively constructs a soda ash+borax+potassium nitrate ternary composite fluxing and stabilizing system, and breaks through the limitation of traditional binary fluxing technology; meanwhile, a three-stage gradient melting, gradient centrifugal spinning and low-pressure constant-temperature solidification coupling preparation process is matched, the glass melting state is effectively optimized, the slag ball generation is greatly reduced, and the glass fiber is refined and homogenized. The application solves the technical problems of high energy consumption, high slag ball content, large fiber dispersion and poor product stability in the existing glass wool production, and has the advantages of simple preparation process, industrialization production and the like, and the prepared glass wool has excellent heat preservation, sound absorption, rebound and weather resistance, and has good application prospect and economic value.

This invention discloses a method for extracting exosomes from sheep milk. The method comprises the following steps: First, fresh sheep milk is centrifuged to obtain a first supernatant, which is then mixed with rennet for enzymatic hydrolysis and centrifuged again to obtain a second supernatant. The second supernatant is then subjected to stepwise gradient centrifugation and ultracentrifugation, the supernatant is discarded, and the precipitate is resuspended to obtain a primary exosome solution. The primary solution is further loaded into an equilibrated size exclusion column, eluted with phosphate buffer, and a specific elution volume of the fraction is collected. The fraction is then concentrated via ultrafiltration to obtain a high-purity sheep milk exosome suspension with a particle size of 100-200 nm. This method, by optimizing centrifugation conditions, chromatographic purification, and ultrafiltration concentration processes, significantly improves the separation efficiency and purity of exosomes. The obtained product can be widely used in biomarker research, drug delivery carrier development, and functional food preparation.

This invention discloses a method for preparing high-viability fat grafts, comprising: aseptically transferring adipose tissue in a closed system while maintaining complete isolation from air during the transfer; performing multi-stage liquid washing on the adipose tissue, including an initial washing and a secondary washing, to remove blood components, tissue debris, and drug residues; subjecting the washed adipose tissue to gradient centrifugation, including an initial low-speed centrifugation and a secondary high-speed centrifugation, to achieve uniform separation of fat cells through a sieve; and collecting the centrifuged fat grafts to obtain a final product with high cell viability and a high proportion of concentrated stem cells. By combining multi-stage liquid washing with gradient centrifugation, efficient purification and uniform separation of fat cells are achieved, effectively reducing the risk of inflammation and removing harmful residues such as lidocaine, resulting in a final fat graft with a high proportion of stem cells and excellent biocompatibility, supporting regenerative medicine applications.

The application discloses yak fetal bovine serum and a preparation process thereof, and belongs to the technical field of biological medicine and cell culture. The unique physiological characteristics of yaks formed by long-term adaptation to extreme environments such as high cold, low oxygen and strong ultraviolet light are utilized, 3-8 month old fetal calves are taken as blood sources, and the fetal bovine serum with high biological activity is prepared through a process of aseptic heart puncture blood collection, low-temperature coagulation, gradient centrifugation, multi-stage sterilization filtration and ultralow-temperature cryopreservation. The detection shows that the core indexes of the serum strictly meet the quality control requirements in the Pharmacopoeia of the People's Republic of China (2025 edition (part three)), and the batch consistency is excellent. The raw material source is unique and natural, the process is stable and controllable, the production can be scaled up, and the serum can be widely applied to the fields of biological pharmaceuticals, cell therapy and basic medical research, and fills the market blank of yak-derived fetal bovine serum.

This invention provides the application of *Viola yedoensis*-derived nanovesicles in the preparation of antitumor drugs, belonging to the field of biomedical technology. The method for preparing *Viola yedoensis*-derived nanovesicles includes the following steps: mixing whole *Viola yedoensis* plants with PBS buffer, homogenizing, and then centrifuging at a gradient to obtain vesicles with a particle size of 100-200 nm. The *Viola yedoensis*-derived nanovesicles of this invention exhibit good biocompatibility and, by inducing mitochondrial-dependent cell death pathways in tumor cells, demonstrate highly efficient and broad-spectrum inhibitory effects on pancreatic cancer, colorectal cancer, and liver cancer, providing a new strategy for achieving highly efficient, low-toxicity, and highly targeted tumor treatment.

This application relates to the field of biomedical detection, specifically disclosing a diagnostic reagent for measuring immune levels and its preparation method. The diagnostic reagent comprises the following raw materials: magnetic nanoparticle-antibody complex, acoustically sensitive hollow microsphere-antibody complex, composite stabilizer, and buffer solution. The magnetic nanoparticle-antibody complex is prepared by co-incubating an antibody with γ-Fe₂O₃ after carboxyl activation. The acoustically sensitive hollow microsphere-antibody complex is prepared by encapsulating perfluoropentane in a lipid film, followed by ultrasonic treatment, gradient centrifugation, and then binding it to an antibody. The composite stabilizer is composed of trehalose, pullulan, green tea EGCG, and thyme oil in a specific ratio. This application also provides a method for preparing the diagnostic reagent, including steps such as raw material mixing, ultrasonic dispersion, and stabilizer addition. The diagnostic reagent of this application is characterized by its ease of operation, high stability, and excellent sensitivity, making it suitable for various fields.

The application discloses an extracellular vesicle extraction system, application and method for extracting extracellular vesicles, and belongs to the technical field of extracellular vesicle separation. The extracellular vesicle extraction system comprises a raw material storage tank, a deep filtration device, a continuous flow centrifuge, a pretreatment buffer tank, a first filtration device, a concentrated liquid tank, a second filtration device, a product collection tank and a waste liquid tank. The extracellular vesicle extraction system is used for extracting extracellular vesicles, and based on the ultrafiltration and microfiltration technology, the extracellular vesicles in the crushed liquid of Chinese herbal medicines or other plants are separated. Compared with the existing differential centrifugation, density gradient centrifugation, ultrafiltration, immunocapture and other technologies, the process is more suitable for large-batch, standardized and high-efficiency extraction, the product yield is high, the speed is fast, the service life of the filter membrane is greatly prolonged, the process cost is reduced, and the process has great commercial value.

This invention belongs to the fields of biotechnology and precision oncology, and discloses a serum-free amplification method for circulating tumor cells (CTCs) based on apoptosis selectivity, along with a dedicated culture medium. This addresses the problems of existing CTC technologies, which rely on physical capture leading to impaired cell viability and low culture success rates. The invention involves mild density gradient centrifugation and erythrocyte lysis of anticoagulated whole blood from patients to obtain a mixed population of leukocytes containing CTCs. This population is then seeded into a serum-free, selective apoptosis medium for three-dimensional culture. The medium contains apoptosis inhibitors and specific growth factors. Utilizing the difference between tumor cells' anti-apoptosis and normal blood cells' susceptibility to apoptosis, leukocyte apoptosis is induced within 4-7 days, while simultaneously supporting CTC survival, adhesion, and clonal proliferation, enabling the amplification of individual CTCs into cell clusters. This method preserves the original activity and heterogeneity of CTCs, is simple to operate, and has good reproducibility, providing a highly active cell source for CTC molecular identification, drug sensitivity testing, and metastasis mechanism research.

The application relates to a purification method of chicken embryo culture influenza virus, and belongs to the technical field of biological medicine. The method is specific capture of inactivated virus liquid from chicken embryos through microspheres; the microspheres swell and adsorb viruses at low temperature, the network structure of the microspheres is triggered to shrink through temperature control, complete virus particles are released, and damage caused by chemical competition elution is avoided; the released viruses are lysed, and then purified through sucrose density gradient centrifugation and molecular sieve chromatography. Through the synergistic effect of impurity removal and specific capture and mild release, the application reduces ovalbumin residues, maintains virus hemagglutinin, and provides an industrialized feasible path for preparation of high-purity and high-immunogenicity influenza vaccine antigen.