54results about How to "Avoid steric hindrance" patented technology

The invention discloses a cyclic chimeric citrullinated peptide antigen and an application thereof. The preparation of the cyclic chimeric citrullinated peptide antigen comprises the following steps: firstly connecting and jogging three small-molecular antigen peptides, namely a citrullinated peptide1, a citrullinated peptide 2 and a citrullinated peptide 3 derived from a silk polymerizing protein / an intermediate filament protein, and then synthetizing a cyclic polypeptide with a similar protein beta-corner structure by forming a disulfide bond through two cysteines inserted into the end N and the end C of a chimeric peptide. The cyclic chimeric citrullinated peptide antigen coats a solid-phase vector to prepare an indirect enzyme linked immunosorbent assay kit used for detecting the hypotype of multiple anti-citrullinated protein antibodies contained in RA (Rheumatoid Arthritis) serum. The cyclic chimeric citrullinated peptide antigen and the ELISA kit thereof which are disclosed by the invention have the advantages of simple preparation and experimental operation process, good result repeatability, qualification or quantification and wide clinical application and scientific research value and are outstandingly enhanced in detection sensibility and diagnosis value on RA compared with an international similar kit.

The invention discloses a copper porphyrin titanium dioxide composite photocatalyst and a preparation method thereof. The specific technical scheme is that: copper porphyrin as shown by the following structure is adsorbed on the surface of a pure anatase type titanium dioxide particle, and the mass ratio of the copper porphyrin to the titanium dioxide is (0.1-1):100. The preparation method comprises the following steps of: according to the mass ratio of the copper porphyrin to the pure anatase type titanium dioxide of (0.1-1):100, dissolving the copper porphyrin by using trichloromethane or dichloromethane; adding the titanium dioxide into the copper porphyrin, and fully stirring the mixture; performing reduced pressure distillation to remove a solvent; collecting the copper porphyrin titanium dioxide composite photocatalyst; and grinding and drying the copper porphyrin titanium dioxide composite photocatalyst. The copper porphyrin titanium dioxide composite photocatalyst can be synthesized simply, has stable properties, high activity and reusability, and can degrade stable organic matters.

The present invention provides a branched poly quaternary ammonium salt (PQAS). The present invention further provides a method for synthesizing the PQAS, wherein branched polyethyleneimine is subjected to an aminomethylation reaction to obtain methylated branched polyethyleneimine, and the methylated branched polyethyleneimine reacts with a halogenated compound to obtain the PQAS. According to the present invention, the method has characteristics of rapidness, efficiency, low cost, simple process and high yield; and the PQAS has the contact type bactericidal capacity, the internal branched structure can embed the guest molecules such as antibiotics, dyes and the like to form the slow release type bactericidal capacity, and the compatibility between the PQAS and the water or resin can be adjusted with different halogenated compounds, such that the PQAS can be used in the fields of antibacterial lotion and material formula, dyeing formulas of plastics, coating materials or films, and the like.

The invention relates to a method for preparing polyolefin-based complex fiber through modified nano-particles. The method comprises the following steps of: implementing hydroxylation to nano-particles, enabling the nano-particles to react with a prepared reagent with a function of initiating living radical polymerization of a monomer, implementing photo-initiated living radical polymerization grafting to the monomer on the surfaces of the nano-particles to form nano-particles covered by multiple layers of organic casings, and mixing the nano-particles with polyolefin to obtain the polyolefin-based complex fiber. The method, in comparison with the prior art, is convenient and simple to operate, and simultaneously, the method can be used for effectively controlling grafting generations of the monomer; the method is high in grafting rate, and molecular chains grated to the surfaces of the nano-particles are narrow in molecular weight distribution, so that compatibility of the nano-particles with the polyolefin as well as dispersion of the nano-particles in the polyolefin are greatly improved; the polyolefin-based complex fiber which is enhanced in mechanical property can be prepared with a low additive amount.

The invention discloses a non-contact positioning auxiliary device used for the minimally invasive intracranial hematoma cleaning operation. The non-contact positioning auxiliary device comprises a fixed rack, a right-angle connecting rod, a right-angle connecting rod fixing shaft, a height adjusting device, a horizontal telescopic boom, a vertical telescopic boom, a vertical-direction laser alignment device and a horizontal-direction laser alignment device, wherein the far end of the horizontal telescopic boom is provided with the vertical-direction laser alignment device, the vertical-direction sector-shaped laser face emitted by the vertical-direction laser alignment device is vertical to the long shaft of the horizontal telescopic boom, a light source points to the downward direction, and a guiding datum line mark is provided; the far end of the vertical telescopic boom is provided with the horizontal-direction laser alignment device, the sector-shaped laser face emitted by the horizontal-direction laser alignment device can rotate along the optical axis of the laser through a rotation adjusting mechanism, and the sector-shaped laser face emitted by the horizontal-direction laser alignment device is enabled to be always vertical to the vertical-direction sector-shaped laser face through the right-angle-shaped adjusting booms. According to the non-contact positioning auxiliary device, the non-frame cantilever laser alignment guide technology is adopted, therefore, the puncture needle is accurately guided continuously during the operation; the non-contact design increases the visual operative field, and thus the steric hindrance in the puncture process is avoided.

The invention discloses a rosin triol ester and a preparation method therefore. The chemical name of the rosin triol ester is trimethylolpropane dehydroabietyate. The preparation method of the rosin triol ester comprises the following steps: by taking dehydroabietic acid and trimethylolpropane as the raw materials, EDC / DMAP as the catalysts, and any one of methylene chloride, tetrahydrofuran and N,N-dimethyl formamide as the solvent, performing an esterification reaction at normal temperature to synthesize the trimethylolpropane dehydroabietyate. The esterification method is completed in one step; the steric hindrance can be effectively overcome; the yield is high; the reaction is performed at room temperature so that the energy consumption can be reduced; the byproducts are soluble in water and easy to purify; the smell is light and few three wastes are generated; and the solvent selection range is wide. The ester prepared by use of the method is wide in use, and can be used as plasticizers and modifiers of various resins, excellent adhesives for pressure-sensitive and thermosensitive adhesive tapes, hot melt coatings, surface activators and pharmaceutical vectors.

A dual-antibody sandwith ELISA detecting method for human soluble p185HER-2 antigen features that the purified and coated P185HER-2 monoclonal antibody is bound to solid supporter, the specimen containing soluble p185HER-2, the purified standard p185HER-2 antigen and the coated antibody are incubated, and another purified and coated p185HER-2 monoclonal antibody marked by horseradish perioxidase is used as detecting antibody. It can be used for serum diagnosis of tumor.

The invention discloses a method for identifying a target RNA (Ribonucleic Acid) of an RNA binding protein through an ultraviolet crosslinking-immune co-precipitation method. According to the method, micrococcalnuclease is used for performing incomplete enzymolysis instead of RNaseA and RNaseT1, and the micrococcalnuclease is completely inactivated by removing calcium ions (Ca<2+>) from a solution after enzymolysis is finished. Moreover, joints are arranged at the two ends of the target RNA in way of connecting 5'RNAlinker firstly and connecting 3'RNAlinker secondly after enzymolysis is finished. The micrococcalnuclease is used for clearing a part of RNAs, so that the degradation of the target RNA is effectively reduced; and due to the adoption of the scheme for connecting the 5'RNAlinker firstly, possible steric hindrance formed at a 3'end by a possibly-existing protein compound is overcome, and the successful rate of a CLIP technology is increased.

The invention discloses a synthesis method and applications of inner-outer dual-layer amino modified SiO2 aerogel. The synthesis method comprises following steps: preparing 20 mL of sodium silicate, removing sodium ions in sodium silicate by a cation exchange resin column; adjusting the pH value of obtained silicic acid solution to 4.0-8.0 by an ammonia solution (0.1-2.0 mol / L) and a hydrochloric acid solution (0.1-2.0 mol / L); rapidly subjecting a beaker containing the silicic acid solution to an ultrasonic treatment, sequentially adding epoxy chloropropane, APETS, ethylene diamine and n-hexane according to a volume ratio of 1:1:1:16, wherein epoxy chloropropane, APETS, and ethylene diamine form a mixed modifier; slowly shaking the beaker under an ultrasonic condition until the solution is converted into gel, then storing the gel for 5 to 24 hours at a temperature of 30 to 65 DEG C, then adding 28 mL of n-hexane into the gel, continuously vibrating the gel for 5 to 24 hours at a temperature of 30 to 65 DEG C; and finally, freeze-drying the wet gel in vacuum for 10 to 48 hours to obtain the inner-outer dual-layer amino modified SiO2 aerogel. The initial adsorbent concentration of the aerogel is 1211 mg / L (humic acid solution), the adsorption balance is reached within 90 minutes, and the adsorption amount is as much as 1194.4 mg / g.

Macromolecular water-soluble conjugates based on synthetic copolymers to which at least one affinity tag, at least one imaging probe, and at least one targeting ligand are bound via covalent bonds. The macromolecular conjugate may be used in identification, visualization, quantification or isolation of proteins and / or cells. The targeting ligand may be attached to the synthetic copolymer via a flexible linker.

The invention relates to a method for preparing group A meningococcal capsular polysaccharide conjugate vaccine. The method includes the following steps that group A meningococcal capsular polysaccharide is diluted, activated and coupled into a group A meningococcal polysaccharide-sebacic dihydrazide derivative together with sebacic dihydrazide; then the group A meningococcal polysaccharide-sebacic dihydrazide derivative and a tetanus toxoid solution are subjected to a catalytic reaction through carbodiimide, so that group A meningococcal capsular polysaccharide and carrier protein conjugate is obtained. According to the method, the sebacic dihydrazide is used as a coupling agent in the preparation process of the group A meningococcal conjugate vaccine; compared with adipic dihydrazide, the sebacic dihydrazide has two more methylenes on carbon chains, molecular chains are longer, the steric hindrance of biomacromolecules can be better resisted, and the conjugation yield is increased.

The invention discloses a catalytic hydrogenation catalyst as well as a preparation thereof and application thereof to the selective hydrogenation reaction of an aromatic nitro compound. The catalystcomprises an activated carbon carrier coated with a modified coating layer and metal quantum dots loaded on the carrier; metal is palladium, and the particle size range of each of the metal quantum dots is between 4 mm and 7 nm; activated carbon is irregular or molded granular activated carbon, and the size is not greater than 1 cm; a pore structure of the activated carbon coated with the modifiedcoating layer is dominated by a mesopore, the micro-pore ratio is reduced to below 10 percent, and the composition materials of the modified coating layer are titanium dioxide, silicon dioxide and titanium silicate. The invention discloses the application of the catalytic hydrogenation catalyst to the reaction of aromatic hydroxylamine shown as a selective catalytic hydrogenation synthesis formula II of the aromatic nitro compound shown as a formula I; the catalytic hydrogenation catalyst has the characteristics of no additive requirement, high conversion rate, good selectivity, high hydrogenation reaction rate, good stability, long catalyst service life and hydrogen recycling.

The invention discloses a preparation method of an extracorporeal circulation anticoagulant modified membrane. The preparation method comprises the following steps: 1, synthesizing carboxylated polysulfone / polyethersulfone; 2, synthesizing apixaban modified polysulfone / polyethersulfone; 3, preparing an apixaban modified polysulfone / polyethersulfone membrane. According to the extracorporeal circulation anticoagulant modified membrane and the preparation method thereof provided by the invention, an Xa factor inhibitor apixaban is grafted to base materials such as polyethersulfone (PES) and polysulfone (PSf), the base materials are modified by the apixaban, and membrane material wall-attached thrombus is efficiently inhibited through signal amplification, so that the membrane has strong anticoagulant and antithrombotic performance. The modification process is simple in synthesis condition, high in controllability and suitable for subsequent industrial large-scale production. According to the novel extracorporeal circulation anticoagulant modified membrane, the steric hindrance effect caused by heparin / heparinoid synthesis is effectively avoided, and meanwhile, the risk of severe bleeding caused by heparin-induced thrombocytopenia (HIT) is reduced.

The invention discloses automatic assembling equipment for a gear assembly, and belongs to the field of gear assembly mounting. The equipment comprises gear sets, a gear set pre-mounting device, a gear set assembling device and a clamping device, wherein a plurality of gears in each gear set are movable gears; the gear set pre-mounting device is used for combining the gears into the gear sets in adisengaged state; the gear set assembling device pushes the movable gears in each gear set to enable the gears to be in meshing transmission; and the clamping device is used for moving in and movingout the gear sets on the gear set assembling device. By arranging the gear set assembling device, the gear sets in the disengaged state are connected in a meshed mode, the problem of steric hindrancecaused by the gear sets in the vertical mounting process is solved, and the gears are prevented from being damaged in the assembling process; and moreover, the meshed gear sets are small in form fluctuation in the moving process, reading deviation of a character wheel system is not likely to be caused, and the mounting stability of the gear sets is ensured.

The invention relates to the technical field of steel pipe machining, and discloses a wear-resistant welded steel pipe, the surface of the steel pipe is coated with a wear-resistant layer, and the wear-resistant layer comprises the following components in parts by weight: 60-80 parts of epoxy resin; 5 to 10 parts of maleated rosin; 4-8 parts of allyl alcohol; 0.5 to 1 part of zinc oxide; 6-8 partsof acetone; and 3-4 parts of chlorinated polyethylene. The wear-resistant welded steel pipe has the following advantages and effects: the maleated rosin and the allyl alcohol are subjected to polycondensation to form a cross-linked structure, and the polymer of the maleated rosin and the allyl alcohol with higher cross-linking degree is blended with the epoxy resin, so that a compact and stable cross-linked structure can be formed among the components, and the wear resistance of the epoxy resin is favorably improved; the chlorinated polyethylene is used for improving the compatibility among all the components; the chlorinated polyethylene is low in molecular weight, steric hindrance is prevented from being formed between resin, all the components can be evenly dispersed, the blend is evenly mixed accordingly, the chlorinated polyethylene can improve the adhesive force of the blend, and therefore the abrasion resistance of the wear-resistant layer can be improved, and the physical andmechanical properties can be improved.

The invention relates to an ampicillin aptasensor based on dual-enzyme mediated cascade signal amplification. The ampicillin aptasensor is prepared by the following steps: taking a double-stranded DNAformed through mutually hybridizing bio-AP, DNA1 and H-DNA as a detection probe, and acquiring a complete APH chain under the assistance of a T4 DNA ligase and an exonuclease III. Through specific binding of biotin-avidin, the APH chain is captured in a microporous plate as an HCR initiating chain, then, hairpin DNA H1 and H2 can open in a cross manner to produce a double-stranded DNA polymer, afluorescent dye SYBR Green I indicator is added, and obvious fluorescence is produced when the fluorescent dye SYBR Green I indicator is embedded into the double-stranded DNA. Based on specific binding between a nucleic acid aptamer and a target object, detection on ampicillin is achieved through changing of fluorescence intensity. The method is high in sensitivity, good in specificity and high inaccuracy and can be applied to the detection on the ampicillin in contaminated foods such as milk.

The invention discloses a catalytic hydrogenation catalyst as well as preparation and application thereof in a tetrahydrofarnesyl acetone selective hydrogenation reaction. The catalyst is composed ofan activated carbon carrier coated with a modification coating and metallic quantum dots supported onto the carrier, wherein the metal is palladium; the particle size of the metallic quantum dots ranges from 3nm to 6nm; the activated carbon is random or formed granular active carbon and has the size of not more than 1cm; the pore structure of the activated carbon coated with the modification coating mainly includes a mesoporous structure, the microporous proportion is reduced to 10% or less, and composition materials of the modification coating comprise titanium dioxide, silicon dioxide and titanium silicate. The invention discloses application of the catalytic hydrogenation catalyst in a reaction of synthesizing hexahydrofarnesyl acetone through selective hydrogenation of tetrahydrofarnesyl acetone. The application has the characteristics of being additive-free, high in conversion rate, excellent in selectivity, high in hydrogenation reaction rate, excellent in stability, long in service life and recyclable in hydrogen.

The invention discloses a preparation method of poly-substituted pyrrolidone derivatives. The preparation method comprises following steps: (1) sequentially adding an alkali, a copper catalyst, a ligand, alkyl amines, alpha-carbonyl alkyl bromide, alkynes, and an organic solvent into a reaction vessel, which has been blown by nitrogen, and carrying out reactions for 12 to 24 hours at a temperatureof 80 to 120 DEG C in a nitrogen atmosphere; (2) filtering the material prepared in the step (1) by diatomite so as to separate solid impurities, and washing the material by dichloromethane to obtainfiltrate; and (3) concentrating the filtrate obtained in the step (2), and processing the concentrated filtrate by column chromatography or thin-layer chromatography to obtain the poly-substituted pyrrolidone derivatives. Heck reaction between tri-substituted alkenes in-situ prepared from amines and alkynes and tert-alkyl halides is realized, and is used to synthesize poly-substituted pyrrolidone. The reaction can overcome the steric hindrance between substrates. Cheap and easily available raw materials are taken as the synthesis blocks; the yield is high, the reaction conditions are mild, the reaction time is short, the choice of substrates is wide, the atom utilization rate is high, and the post treatment is simple and green.

The invention provides a pFTM3GW recombinant vector as well as a preparation method and application thereof. The pFTM3GW recombinant vector comprises a specific T cell receptor and a lentiviral vectorpFTM3GW, wherein the specific T cell receptor is used for identifying an antigen NY-ESO-1; the specific T cell receptor used for identifying the antigen NY-ESO-1 sequentially comprises an alpha chain, furin, SGSG flexible amino acid, a linker peptide and a beta chain. In the pFTM3GW recombinant vector, the T cell receptor comprising the alpha chain, the furin, the SGSG flexible amino acid, the linker peptide and the beta chain is inserted into the pFTM3GW vector, and all the components have synergistic interaction, so that the alpha chain and the beta chain of the T cell receptor are promotedto form a stable structure and achieve high-efficiency expression, the signal transduction is promoted, the transfection efficiency and a targeted effect are improved, an immunotherapy effect is promoted, and the pFTM3GW recombinant vector is wide in application prospect and market value.

The invention discloses an ordered polystyrene@gold composite microsphere array with dynamically controllable gaps as well as a preparation method and application thereof. The array is a thermotropicshrinkage polyvinyl chloride substrate and an ordered gold composite microsphere array arranged on the thermotropic shrinkage polyvinyl chloride substrate, wherein distance between gold composite microspheres forming the microsphere array is 50-65 nm, the sphere diameters of the microspheres are in a range of 150-935 nm, and the gold composite microspheres are formed by coating the surfaces of polystyrene spheres with gold films. The method comprises the following steps: firstly, placing a single-layer colloidal crystal template formed by polystyrene colloidal spheres on the thermotropic shrinkage polyvinyl chloride substrate; then carrying out plasma etching on the obtained single-layer colloidal crystal template on the thermotropic shrinkage polyvinyl chloride substrate; and depositing the gold films on the obtained single-layer non-close-packed polystyrene sphere template on the thermotropic shrinkage polyvinyl chloride substrate by using a sputter coating method to obtain a targetproduct. The array can be easily and widely commercialized for accurate and repeated detection of a trace amount of a to-be-detected object attached to a surface-enhanced Raman scattering active substrate.

The invention relates to a copper-cerium double-metal modified 4A molecular sieve desulfurization adsorbent as well as a preparation method and application thereof. The adsorbent takes copper and cerium as active components and takes a 4A molecular sieve synthesized by kaolin as a carrier material. The method comprises the following steps: (1) preparing a copper source solution, carrying out copper impregnation modification on a 4A molecular sieve through a water bath, and calcining after centrifugal drying to obtain a copper modified molecular sieve; and (2) preparing a cerium source solution, performing cerium impregnation modification on the copper modified molecular sieve through a water bath, and calcining after centrifugal drying to obtain the copper-cerium double-metal modified 4A molecular sieve desulfurization adsorbent. The adsorbent is applied to the field of fuel oil deep desulfurization. Compared with the prior art, thedsorbent provided by the invention has the advantages of capability of realizing excellent desulfurization performance under normal temperature and normal pressure conditions, small influence on components in the fuel, high octane number, low investment, low operation cost, low energy consumption, high desulfurization rate and the like.

The invention discloses a preparation method of a high-energy-storage battery diaphragm material. Polyethylene maleic anhydride is grafted on and coats the surface of magnesium hydroxide, and then resin grafted, coated and modified magnesium hydroxide and matrix resin are subjected to melt blending to prepare the battery diaphragm, so that the mechanical strength, the thermal stability, the wettability, the air permeability and the safety of the diaphragm material can be improved at the same time, and the risk that an inorganic material is disengaged from the diaphragm is completely avoided. The diaphragm material is longitudinally stretched at a relatively low temperature and then longitudinally / transversely stretched synchronously at a relatively high temperature, so that the shape and the pore diameter of micropores in the diaphragm can be effectively ensured, and the micropores are prevented from being seriously deformed. Through a two-stage grafting reaction and microwave heating,grafting and coating of surface resin are carried out on magnesium hydroxide, and grafting and coating of magnesium hydroxide can be uniformly and completely realized.

The invention discloses a photoetching method. The method comprises the following steps of: carrying out plasma treatment on the surface of a substrate by adopting the mixed gas of CO2 and H2; rotatably coating photo resistance (PR) on the surface of the substrate to form a photoetching pattern. By adopting the method, photoetching pattern flaking can be avoided.