1681 results about "Freeze thawing" patented technology

A prosthesis for replacing or supplementing a nucleus pulposus of an intervertebral disk is an expandable container having flexible walls, the container being adapted to be inserted into a central cavity of an intervertebral disk through a narrow cannula, and the flexible walls are made from a biocompatible hydrogel. A preferred hydrogel is a cryogel formed from an aqueous solution of poly(vinyl alcohol) and poly(vinyl pyrrolidone). The prosthesis may be prepared by dip-coating a mandrel with an aqueous solution of a hydrogel-forming polymer or mixture of such polymers, gelling the coated solution by chilling, and subjecting the gelled coating to a series of repeated freeze-thaw treatments. In use, the prosthesis is inserted into a central cavity of an intervertebral disk and filled with biocompatible material, e.g., a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel, particularly a thermogelling hydrogel.

An antibody-containing solution formulation comprising an organic acid and a surfactant as stabilizers; a method for suppressing the formation of visible insoluble matter and/or insoluble particles due to the presence of metal ions in an antibody-containing solution formulation, which comprises adding an organic acid to the solution; a method for suppressing the formation of visible insoluble matter and/or insoluble particles during shaking and freezing-thawing of an antibody-containing solution, which comprises adding a surfactant to the solution; and a method for stabilizing an antibody-containing solution, which comprises adding an organic acid and a surfactant.

The present invention provides surgical training aids formed from hydrogels and adapted to exhibit realistic mechanical properties mimicking those of real organs. Surgical training aids are preferably fabricated by subjecting a concentration of polyvinyl alcohol to freeze-thaw cycles in a mold designed to approximate the shape of an organ, and process parameters are selected to tailor the mechanical properties of the formed hydrogel to those of the organ simulated by the surgical aid. The mechanical properties of the hydrogel forming the surgical training aid may be tailored by incorporating bacterial cellulose and by applying strain during hydrogel formation, thereby producing controlled anisotropy.

An object of the present invention is to provide a method for producing an ADM suitable as a scaffold for a cultured skin, that is, a separation and decellularization method that enables various types of extracellular matrixes such as a basement membrane to be preserved, allows the epidermal layer to be peeled off easily, and does not cause any damage to the dermal matrix. The present invention relates to a skin separation and decellularization method comprising a step of freeze thawing harvested skin and then separating the skin into epidermis and dermis by a treatment with hypertonic saline, and a step of washing the separated dermis.

A red blood cell storage composition includes a composition of red blood cells and biochemistry altering reagents, the biochemistry altering reagents being present at a concentration so as to reduce the percent hemolysis of the red blood cells during the freeze-thaw cycle below that of the percent hemolysis of the red blood cells in the absence the biochemistry altering reagents. The red blood cell storage composition preferably includes reagents selected from: modifiers of glycolytic/metabolic components, modifiers of antioxidant potential, effectors of intracellular ionic distribution, modifiers of membrane fluidity, modifiers of cytoskeletal structure, effectors of the cyclooxygenase second messenger pathway, effectors of the lipoxygenase second messenger pathway, effectors of the hexose monophosphate second messenger pathway, effectors of the phosphorylation second messenger pathway, modifiers of specific messenger molecules, and combinations thereof.

The invention provides a preparation method of a flexible polyaniline conductive composite hydrogel material, and belongs to the technical field of functional polymer materials. According to the method, a flexible conductive material with good mechanical strength and electrochemical property is prepared by utilizing the properties and characteristics of polyatomic acid of phytic acid, by taking the phytic acid as an acid doping agent and a gel crosslinking factor and taking polyvinyl alcohol hydrogel as a skeleton. The method comprises the following steps: dissolving polyvinyl alcohol into water to form a solution and matching the solution with phenylamine and phytic acid at a proportion to form a solution A; dissolving initiating agent ammonium persulfate into water to form a solution B; quickly mixing the solution A and the solution B at a low temperature, so that in situ polymerization is performed on the phenylamine in a polyvinyl alcohol aqueous solution, so as to form phytic acid-doped polyaniline hydrogel; placing the phytic acid-doped polyaniline hydrogel into a refrigerator for freezing, so as to form the flexible polyaniline conductive composite hydrogel material by a cyclic freeze thawing. The flexible polyaniline conductive composite hydrogel material prepared by the method has good electrochemical property, mechanical strength and flexibility; the preparation method is simple, and the cost is low, and the preparation method has wide application prospect in the fields of flexible energy storage materials and biomedicine.

The invention discloses hydrogel dressing which is composed of an upper layer and a lower layer. The lower-layer hydrogel is prepared by utilizing freeze thawing radiation method, and the upper-layer hydrogel is prepared by utilizing the radiation method; both the layers of hydrogel contain water-soluble polymer, and solvent for the residual; wherein, the lower-layer hydrogel contains polyvinyl alcohol. The invention also discloses a hydrogel-dressing preparation method which comprises the following steps: after the deaeration treatment of the water-soluble polymer solution containing polyvinyl alcohol, the hydrogel is prepared by utilizing circulating frozen thawing method; the water-soluble polymer solution after the deaeration treatment is positioned on the hydrogel, and then irradiation is performed under the high-energy rays. The hydrogel dressing has not only excellent strength and toughness, but also high transparence and wound fluid absorption ability. Meanwhile, the hydrogel dressing requires no additional chemical cross-linking agent or initiating agent, medical adhesive, and no reinforcing layer, such as fiber fabrics and woven fabrics, the two layers can be bonded firmly, and the preparation and the disinfection can be finished synchronously.

The invention which belongs to the field of civil engineering equipment relates to a full-automatic, digital and large frozen soil direct shear apparatus. The large frozen soil direct shear apparatus which comprises a shear box, a refrigeration system of an upper shear box, a refrigeration system of a lower shear box, a vertical servo loading and monitoring system, a horizontal servo loading and monitoring system, and a measurement and control system is to determine the shear strength of the freeze-thaw interface of the frozen soil or determine the shear strength of full frozen soil and full thawy soil. The size of a frozen soil sample in the embodiment of the invention is 305mm*305mm*200mm, static force and a layered compacting method are adopted to prepare remolded soil samples of different initial water contents and dry densities for shear tests; temperature control systems of the upper shear box and the lower shear box are adjusted to control the temperatures of soils in the shearboxes to guarantee the shear plane to be superposed with the freeze-thaw interface of the frozen soil sample. The direct shear apparatus of the present invention solves problems that the difficulty of testing the shear strength of the freeze-thaw interface is large, the shear tests of coarse grain soil are difficult and the like and provides reasonable design parameters for civil engineering and traffic engineering in cold or highly cold regions.

The invention discloses a solar photothermal conversion material and a preparation method thereof, wherein the method comprises the steps of: a light absorbing material, a water-soluble monomer, an initiator and a crosslinking agent are mixed and dispersed in water to obtain a reaction liquid; or the light absorbing material, a water-soluble polymer and the crosslinking agent are mixed and dispersed in the water to obtain a reaction liquid; the reaction liquid is adsorbed by a sponge, and gelatinized to obtain a hydrogel, and after several cycles of freeze-thawing, freeze-drying and dissolvingof the hydrogel in water until the hydrogel is saturated to swell, the solar photothermal conversion material is obtained. The porous property of a sponge material enhances the water absorption of the solar photothermal conversion material, and can solve the salt deposition problem, and the solar photothermal conversion material has self-cleaning property. In the solar photothermal conversion material, the light absorbing material ensures the light absorption of the solar photothermal conversion material, and the hydrogel material can reduce the latent heat required for evaporation of water,so that high photothermal conversion efficiency and high evaporation rate can be ensured.

The present invention provides a freeze-thawing circulation detection apparatus for nature saline soil, wherein the apparatus is used for detecting the formation process of saline soil under nature environment conditions and detecting the frost heaving and melt sinking change law of the saline soil during multiple freeze-thawing circulation processes. According to the present invention, the upper portion of a sample tube of the apparatus is connected with a low temperature constant temperature box for detecting the temperature change under a nature state, temperature setting is decided according to the air temperature of a region, the bottom of the sample tube is fixed with a temperature control head, the detected temperature between the soil under the nature conditions is set as +5 DEG C, and the temperature control head on the bottom is connected with a water replenishment device for detecting groundwater and salinity replenishment under the nature conditions; and with the freeze-thawing circulation detection apparatus for nature saline soil, the freeze-thawing circulation mechanism of the saline soil can be well reflected so as to provide reference for engineering construction in the saline oil area.

The invention relates to a preparation method of a fluorinated acrylate emulsion. A method of semi-continuous seed emulsion polymerization is used, so that a fluorine monomer is concentrated in a copolymer shell; meanwhile, a reactive emulsifier is used, so that emulsifier molecules are combined on the surface of emulsion particles via stable covalent bonds. Specific method comprises the following steps: firstly, preparing a nuclear emulsion, dropping a shell preemulsion on the basis of the shell preemulsion, and polymerizing through a semi-continuous seed method to obtain an aqueous fluorinated acrylate shell emulsion. Due to the preparation technique, a fluorine-containing monomer is placed in the shell, so that the efficiency is maximized, advantages of a fluorine-containing polymer is shown as much as possible; the emulsion obtained through the method has excellent storage stability, calcium ion stability, freeze-thaw stability and mechanical stability.

The invention discloses a method for preparing a high-strength polyvinyl alcohol hydrogel. The method comprises the following steps: taking polyvinyl alcohol as an initial raw material, and heating and dissolving in a water bath, thereby obtaining a polyvinyl alcohol aqueous solution; performing repeated low-temperature freezing-thawing on the polyvinyl alcohol aqueous solution, thereby obtaining polyvinyl alcohol hydrogel; adding the polyvinyl alcohol hydrogel into a saturated saline solution, thereby obtaining the high-strength polyvinyl alcohol hydrogel. According to the invention, a hydrogen bond cross-linking structure and a microcrystalline domain are sequentially constructed by a two-step method, and then the high-strength polyvinyl alcohol hydrogel is prepared. The preparation method disclosed by the invention is simple and environmental-friendly, and the prepared high-strength polyvinyl alcohol hydrogel has excellent mechanical property, non-toxicity and high biocompatibility.

A cement-emulsified asphalt mortar used for railway and overhead railway in urban area contains cement and its additive, emulsified asphalt, sand, water, water-reducing agent, aluminium powder, surfactant, defoaming agent, polyacrylic fibres and chlorobutadiene latex. Its preparing process is also disclosed. Its advantages are high flowability, high strength and freeze-thawing resistance, and no environmental pollution.

The invention discloses a nanometer bacterial cellulose\polyvinyl alcohol\polyethylene glycol porous composite hydrogel. The porous composite hydrogel comprises nanometer bacterial cellulose, polyvinyl alcohol and polyethylene glycol. The invention also discloses a preparation method of the porous composite hydrogel. The method comprises the following steps: hydrolyzing clean bacterial cellulose by sulfuric acid to obtain a nanometer cellulose solution, carrying out neutral treatment, mixing the treated solution in a polyvinyl alcohol solution, carrying out ultrasonic dispersion until uniformity, adding a small amount of a polyethylene glycol solution, carrying out ultrasonic stirring mixing, adding the above obtained mixed solution into a glass bead template in a dropwise manner, repeatedly freeze-thawing to cross-link the obtained mixture, and drying to obtain the porous composite hydrogel. The porous composite hydrogel prepared in the invention has the advantages of low cost, mild reaction, fast speed, good biocompatibility, high mechanical strength, uniform porous structure, and wide application prospect in the fields of biomedical science and tissue engineering.

The invention discloses a method for preparing health food capsules by using cordyceps militaris and cocoon extracts, and aims to extract various nutrient substances with natural activities from the cordyceps militaris and cocoon to produce different types of nutrient health products, so that the utilization rate of the cordyceps militaris and cocoon is fully improved, and the market demand is met. The method is characterized by comprising the steps of extracting the nutrient substances from the cordyceps militaris and cocoon by performing freeze thawing, combined enzymolysis and aqueous alcohol precipitation sub-step extracting methods; adding a proper quantity of auxiliary materials into the nutrient substances to fully and evenly stir and sieve to prepare the particles; filling the particles into the capsules; wiping off residual powder adhered to the capsule shells; waxing; polishing; and sterilizing the capsules in a radiation mode after the capsules are packaged so as to obtain the finished product.

The invention discloses a method for extracting coal bed gas from circulating pulse type low temperature freeze-thawed anti-reflection coal. Firstly, a borehole and multiple rows of guiding slots are constructed in a coal bed, the guiding slots are communicated with the borehole and extend to two sides of the borehole in the direction perpendicular to the borehole in the coal bed, and coal bed gas extraction boreholes are formed at the outer ends of the guiding slots. A liquid low-temperature medium is injected into the borehole and the guiding slots in a high-pressure pulse mode, the coal bed is freeze-thawed by adopting a pulse circulating low temperature freeze-thawing method to fracture for increasing reflection, and a coal bed gas extraction fracture network is thus formed. Coal bed gas is extracted via the coal bed gas extraction boreholes. By combining freeze-thawing erosion with coal bed gas extraction and combining pulse circulating injection of the liquid low-temperature medium with freeze-thawing phase change fracture, the method significantly improves the anti-reflection efficiency of coal. The method is simple, feasible and low in construction cost, can effectively improve the single-pore extraction quantity and extraction concentration of coal bed gas and prolong the attenuation time of gas concentration, and is particularly suitable for coal bed gas extraction in low-osmosis and high-gas bearing coal beds.

The invention belongs to the technical field of medicament, and particularly relates to preparation and application of phycocyanin extract. The phycocyanin extract is prepared by the following steps of: crushing spirulina cell walls of spirulina powder to obtain a crude extract by a repeated freeze-thawing method at the temperature of between 20 DEG C below zero and 4 DEG C; depositing the crude extract to obtain a crude protein extract by using 50 to 60 mass percent of ammonium sulfate; and then extracting and purifying the crude protein extract by adopting double aqueous phases, and removing salt by using excess infiltration to obtain phycocyanin extract solution. The phycocyanin extract mainly comprises phycocyanin, and the aqueous solution of the phycocyanin extract has the absorbance characteristics that A620/280 is slightly equal to 3.0+/-0.2 and A620/650 is slightly equal to 2.2+/-0.1. The phycocyanin extract is obtained by mainly combining the processes of ammonium sulfate deposition, double aqueous phase extraction, dialysis and salt removal and the like; and the phycocyanin extract administrated to S180 sarcoma mice with different dosages shows good tumor inhibiting effect and has no obvious toxicity on the spleen and the thymus gland.

This invention relates to a formulation with the addition of low density additives of volcanic ash, hollow ceramic microspheres or a combination of microspheres and volcanic ash or other low density additives into cementitious cellulose fiber reinforced building materials. This formulation is advantageously lightweight or low density compared as compared to current fiber cement products without the increased moisture expansion and freeze-thaw degradation usually associated with the addition of lightweight inorganic materials to fiber cement mixes. The low density additives also give the material improved thermal dimensional stability.

The invention relates to a method for preparing an amorphous cellulose aerogel, and concretely relates to an amorphous cellulose aerogel with an ionic liquid. The invention aims to solve technical problems of shapelessness and bad toughness in present inorganic aerogel preparation processes. The method comprises the following steps: 1, dissolving cellulose in the ionic liquid, freeze-thawing multiple times, and displacing the ionic liquid out with a displacement liquid to obtain an amorphous cellulose hydrogel; and 2, carrying out supercritical drying and critical point drying on the hydrogelto obtain the amorphous cellulose aerogel. A novel cellulose material amorphous cellulose aerogel is prepared in the invention. The ionic liquid can be recovered and recycled, so a green preparation technology is realized, and the prepared aerogel has the advantages of nontoxicity, good shape and very good mechanical strength. The prepared new product cellulose aerogel can be applied to heat insulation, sound insulation, inorganic nanoparticle loading, virus filtration, biological scaffolds and the like, and the preparation method provides a new approach for the high efficiency utilization oflow quality biomass resources.