34 results about "Dna double helix" patented technology

The invention relates to the technical field of nursery garden seedling root cutting, and discloses a drilling-milling composite-type circumferential nursery garden seedling root cutting tool bit. The drilling-milling composite-type circumferential nursery garden seedling root cutting tool bit comprises a drill bit, a tool body and a rotating mandrel; the tool body is composed of milling cutter segments, the drill bit is designed by simulating the head and neck curve of a pangolin, the milling cutter segments are designed by simulating a kapok tree trunk, and kapok thorn-shaped tools are arranged in a DNA double helical mode; the drill bit and the milling cutter segments are connected and then integrally installed on the rotating mandrel; the drill bit is provided with a first chip removal groove in the axial direction of the drill bit, and the milling cutter segments of the tool body are provided with blade grooves; the tools are installed in the blade grooves; the drill tool is in tooth-embedded connection with the milling cutter segments of the tool body through dovetail grooves, and the milling cutter segments are in tooth-embedded connection with each other through dovetail grooves. According to the drilling-milling composite-type circumferential nursery garden seedling root cutting tool bit, annular or square cutting is completed through a drilling-after-milling mode, that is, the drill bit drills into a soil layer by about one meter, and then milling is performed on the soil layer through the helical milling cutter segments; the tool bit can lower the labor intensity and working noise in the root cutting process, improve the labor efficiency and prevent a danger from occurring due to close contact of people and the tools.

The invention discloses a preparation method of a paper-based photocathode biosensor for detecting microRNA. A gold nano-particle layer is coated in a working area of a paper-based carbon working electrode; polyhedral cuprous oxide is electrodeposited and lots of silver sulfide quantum dots can be loaded, and a photoelectric sensitized structure is formed, so that the cathode photocurrent is increased substantially; and in the presence of the target microRNA, a double-strand-specific-nuclease-induced target cycle reaction and a cascaded stem-branch hybridization strand reaction are made to obtain a negatively charged dendritic DNA double-helix structure. After assembling of positively charged gold nanoparticles, a gold tree with the good glucose oxidase mimicking activity is formed, so that the glucose oxidation reaction is catalyzed, the dissolved oxygen of the electron acceptor is consumed, the cathode photocurrent signal is reduced, and sensitive detection of the microRNA is realized.

The invention discloses traceless yoga trousers. The trousers comprise a trouser body and elastic sheets arranged on the outer side of the trouser body, wherein the elastic sheets are connected to the trouser body through hot melt adhesive in a hot press mode, and the trouser body includes trouser legs and underpants; the trouser legs are connected with the underpants through hot melt adhesive film in a hot press mode, and the elastic sheets include trouser leg elastic sheets which are arranged on the trouser legs in a DNA double-helix shape. According to the traceless yoga trousers, the trouser legs are connected with the underpants through the hot melt adhesive film in a hot press mode, and the elastic sheets are connected to the outer surface of the trouser body through the hot melt adhesive in a hot press mode, so that traceless connection is achieved between the trouser body and the elastic sheets and between the underpants and the trouser legs; therefore, no machine sewing is needed, no impressions are produced on skin, and no projecting lines are produced when the trousers are worn, so that the trousers are comfortable and beautiful to wear.

The invention discloses a method for carrying out cyclic polymerization label-free fluorescence detection on PD-1 (Programmed Cell Death-1) based on a nucleic acid aptamer, and relates to an establishing method and application of a fluorescence spectrum sensor in the field of a signal amplification technology. The method comprises the following steps: complementarily hybridizing a self-designed DNA (Deoxyribonucleic Acid) single chain with the PD-1 nucleic acid aptamer, adding a to-be-detected matter PD-1, and unwinding DNA double chains because a binding force between the to-be-detected matter PD-1 and the PD-1 nucleic acid aptamer is greater than the coordination ability of DNA double helices; carrying out cyclic amplification on released DNA single chains under the action of various tool enzyme, and carrying out cascade signal amplification; changing a trigger fluorescence signal of an amplification product through conformation, thus realizing high-sensitivity and high-selectivity nucleic acid optical sensory detection of the PD-1. By virtue of the method disclosed by the invention, the detection limit of the PD-1 can be up to 0.3ng/mL, and detection of the PD-1 in biological samples such as serum can be met.

The invention discloses a preparation method of tuna extract with inhibitory effect on cancer cells, and preparation steps include compound enzyme enzymolysis, isoelectric point precipitation, ultrafiltration, nanofiltration, HPLC elution and freezing drying. The beneficial effects are that tuna protein has a lot of marine Brevibacterium oxydan secreting alkaline protease and undariapinnatifida protease cleavage sites, after the enzymolysis, lots of different lengths of peptide chains can be obtained, and the enzymolysis efficiency is high; the preparation method has the advantages of being simple, less in equipment, low in preparation cost, accurate in operation data of each step, good in repeatability, and suitable for mass production; the purity of the prepared bioactive short peptide is high, DNA double helix structure unwinding of the cancer cells can be effectively inhibited by the short peptides, so that the DNA replication of the cancer cells can be inhibited, the cancer cells stay in interphase of cell division, secretion of E-cadherin can be promoted, moveability of the cancer cells is reduced, and the transfer speed of the cancer cells is reduced.

The invention provides a biology teaching and research device which comprises two rods and a plurality of basic group models. The two rods are arranged in a DNA (deoxyribonucleic acid) double-helix manner, two ends of each basic group model are connected on the two rods, the basic group models are parallelly arranged along the axis directions of the rods, the rods comprise metal shaping hoses, soft rubber bars are connected in the metal shaping hoses in a sleeved manner, elastic metal wires are arranged in the soft rubber bars, each basic group model comprises clamping parts and a model rod, the clamping parts are positioned at two ends of each basic group model, the model rod is positioned in the middle of each basic group model, the two clamping parts and two rods are clamped in a one-to-one correspondence manner, two ends of each model rod are in one-to-one correspondence to the two corresponding clamping parts and detachably connected with the two clamping parts, each model rod comprises two detachably connected sub models, and basic markers are arranged on sub models. According to the biology teaching and research device, the basic group models can be disassembled, the basic group models and the two double-helix rods can be disassembled, DNA models are disassembled and assembled by learners in the use process, and learning effects are improved.

The invention belongs to the technical fields of heat supply, refrigeration, water supply and purification, and in particular relates to a DNA double-helix micron-scale filter element suitable for liquid exhausting and having an extremely excellent contaminant removing effect. The DNA double-helix micron-scale filter element consists of a central shaft pipe and a filter screen with a double-helix oblique cubic structure. The filter screen is welded by surface-modified metal wires to form the double-helix oblique cubic structure, the inner wall of the filter screen is welded on a central casing pipe and the filter element integrally presents the 'DNA' double-helix structure. The DNA double-helix structure filter element has stable structure, small fluid resistance and large filtering surface area, enhances the exhausting and contaminant removing effect treatment capability, and is suitable for removing free and dissolved gases from the fluid. The heating and ventilation industry needs to remove gas from the system most urgently at present.

The invention provides a method for quantitative detection of the activity of PARP-1 based on an electrochemical sensing electrode with deposited polyaniline. The method comprises the following steps:modifying a gold electrode by using a specific DNA double-helix structure with a mercapto group so as to obtain a specific unit exciting PARP-1; with a part of PARP-1 as a catalyst for nicotinamide adenine dinucleotide (NAD<+>), cleaving NAD<+> into two parts, i.e., poly(ADP-ribose) (PAR) and nicotinamide, wherein one of the two parts is used as a linking agent for linking with a PAR unit; subjecting PARP-1 to repeated catalysis so as to form a negatively-charged PAR unit; preparation of the electrochemical sensing electrode with deposited polyaniline; and detecting the generated current signals of polyaniline by using an electrochemical process so as to detect the activity of PARP-1. Unlike conventional methods for determining residual NAD<+> substrates by using enzyme-linked immunosorbent assay, the method provided by the invention can quantitatively measuring the activity of PARP-1 and is greatly improved in sensitivity. The method does not need preparation of complex materials andhas the advantages of low cost, rapidness and easiness.

The invention relates to a virus-imitated DNA polyhedral frame structure, which is a regular icosahedron frame structure, each edge is composed of four DNA double helixes, the virus-imitated DNA polyhedral frame structure is provided with an outer layer structure and an inner layer structure, the edges at the vertexes of the outer layer structure are bridged by five T single-stranded DNA, and the edges at the vertexes of the inner layer structure are bridged by one T. In addition, the invention further relates to a packaging and assembling composition containing the DNA material and a construction and manufacturing method of the composition. Finally, the invention also relates to application of the DNA polyhedral frame structure in the fields of nano space molecule operation level, acellular in-vitro amplification system and virus infection simulation. The DNA polyhedral frame structure recorded in the invention is a regular icosahedron, and compared with the prior art, the DNA polyhedral frame structure has a unique double-layer structure and more anchor points, so that the DNA polyhedral frame structure has better structural rigidity, and an assembly prepared from the DNA polyhedral frame structure also has better integrity and more complete packaging; and compared with the prior art, the application of the method in various fields also has substantive progress.

The invention discloses quinomycin-A preparation and a preparation method and application thereof. The quinomycin-A preparation comprises, by weight percent, 1-30% of quinomycin-A, 10-12% of emulsifier, and 60-89% of organic solvent. The even and stable quinomycin-A preparation is prepared by using quinomycin-A as raw material, emulsifying the quinomycin-A in a reactor by the emulsifier and mixing with the organic solvent. The preparation method is simple and low in preparation cost. After spraying, the quinomycin-A preparation is distributed on the surface of a crop in a particulate manner and accordingly is more beneficial to directly inhibiting and killing pathogenic bacteria, and drug effect is improved. The quinomycin-A preparation is efficient and low-toxicity and is pollution-free biopesticide. The quinomycin-A preparation controls disease damage mainly by breaking cell membranes of the pathogenic bacteria and inhibiting formation of DNA (deoxyribonucleic acid) double helixes. The quinomycin-A preparation is effective in controlling phytophthora caused diseases such as Phytophthora melonis Katsura, pepper phytophthora blight and pineapple heart-rot disease, less than conventional drugs in consumption, and can overcome drug resistance of phytophthora to conventional pesticides.

The invention discloses a method for solving the imbalance of allele amplification through PCR additives. This method is aimed at the situation of unbalanced allelic amplification caused by "some alleles to be tested melt to form complex secondary structures during PCR amplification or/and DNA double-strand melts insufficiently". The method comprises the steps of: reducing the stability of double-helix DNA by adding PCR additives to the original PCR reaction system, thereby solving the problem of unbalanced allelic amplification; the original PCR reaction system is the allele to be tested The PCR reaction system used when the amplification of alleles is unbalanced in the PCR amplification of genes. Experiments have proved that this method can effectively solve the allele amplification caused by "part of the alleles to be tested melted during the PCR amplification process to form a complex secondary structure or/and DNA double-strand melts insufficiently" unbalanced.

The invention discloses a preparation method of a modified nanometer resin based wood lacquer, and belongs to the technical field of coating preparation. Firstly, bisphenol A epoxy resin is used for carrying out effective modification on acrylic resin under the effect of an emulsified liquid and an initating agent. Due to the fact that the bisphenol A epoxy resin is of extremely high cohesive force and a compact molecular structure, the distribution uniformity of nanometer silver particles in a film is improved, simultaneously a compact and firm network structure can be formed on the surface of a base through a silica solution, when silver nitrate loaded on the surface of the silica solution reaches a microorganism cell membrane, silver ions are slowly released under the effect of a home-made glucose reduction solution, due to the fact that the cell membrane is of negative electricity, the microorganism cell membrane is destroyed at an extremely low concentration through the silver ions depending on coulomb force, active oxygen ion free radicals and hydroxyl free radicals are generated, a reaction can perform with bacteria, a DNA double helical structure is destroyed, metabolic disturbance plays a bacteria inhibition role, and the wood lacquer has wide application prospects.

The present invention discloses a nucleotide model device comprising two elongated bodies arranged in a DNA double helix, and further comprising a plurality of groups of connectors, wherein two ends of each connector are respectively connected to the two elongated bodies, a plurality of groups of connectors are sequentially arranged along the axis of the elongated bodies, each connector comprises two connecting posts in butt joint, the connecting posts are configured to have four different appearance marks, each elongated body comprises a plurality of sub-columnar bodies which are detachably connected, the center of each sub-columnar body is provided with a convex member, the convex member is provided with a first connecting portion, and two ends of the connecting post are provided with a second connecting portion and a third connecting portion respectively; the convex member is connected to the sub-columnar body through the detachable connection between the first connecting portion and the second connecting portion, and two sub-columnar bodies form one connector via detachable connection of two third connecting portions. The nucleotide model device provided by the present invention can be used by the learner to connect each element as required in a step-by-step manner into a final double helix model.