Abstract: The present invention discloses a one-way limiting expandable artificial heart valve which comprises a valve seat (1), a valve leaflet stent (2) and three valve leaflets (3) wherein the valve seat (1) comprises a one-way limiting expandable annular metal seat (4), the annular metal seat (4) is composed of three sections of seat body units (5), the head end of each section of seat body unit (5) is sequentially provided with a first rivet (8), a limiting protrusion (7) and a first long circular groove (6), the tail end of each section of seat body unit (5) is sequentially provided with a second long circular groove (9), a second limiting hole (11) and a first limiting hole (10), and a second rivet (12), and the artificial heart valve has a normal use original state and a one-way limiting expansion state.

Abstract: The disclosure provides a new method for preparing a WPU synthetic leather foaming layer based on a Pickering foam template method. The key of the method is to use the soft waterborne polyurethane as raw materials, add waterborne crosslinking agent and hydrophobic inorganic solid particles as Pickering waterborne foam stabilizers to obtain Pickering waterborne foam slurry of polyurethane latex particles through high-speed emulsification; and dry the slurry to obtain the waterborne polyurethane foam layer. The preparation process does not use any organic solvents, is clean and environmentally-friendly, and is simple to operate, making it easier to realize industrialized production. In addition, the Pickering foam has strong interface stability, which effectively solves the problem of difficult adjustment of the pore size caused by the accumulation and collapse of bubbles during the drying process of the mechanical foaming method, and the prepared synthetic leather foam layer has good hygienic properties.

Abstract: The present invention belongs to the field of genetic engineering, and particularly relates to a genetically engineered dual-targeting chimeric antigen receptor. The present invention provides a genetically engineered dual-targeting chimeric antigen receptor and a host cell thereof in response to up-regulated expression of PD-L1 in tumor cells and immune cells after these cells are exposed to malignant serosal cavity effusion. The dual-targeting chimeric antigen receptor provided by the present invention competitively binds to PD-L1 to transform an inhibition signal of PD-L1 into an activation signal and to enhance the killing activity of T cells; meanwhile, 4-1BB introduced downstream thereof can promote proliferation and survival of T cells. In addition, the present invention also discloses a host cell expressing the above dual-targeting antigen receptor and a use thereof in preventing or treating solid tumors.

Abstract: Disclosed are a method for preparing an anisotropic flake nanocrystalline rare earth permanent magnet material and a rare earth permanent magnet material. In the disclosure, the method includes: step 1, preparation of a precursor flake nanocrystal magnetic powder, where a number of grains of flake nanocrystals inside the precursor flake nanocrystalline magnetic powder accounts for not less than 85% of a total number of grains inside the precursor flake nanocrystalline magnetic powder; step 2, orientation treatment by hot deformation: subjecting the precursor flake nanocrystalline magnetic powder or a green body prepared from the precursor flake nanocrystalline magnetic powder to the hot deformation, such that flake nanocrystals are regularly arranged; and step 3, post-processing for optimizing orientation.

Abstract: A split type precisely-anchorable transcatheter mitral valve system comprises a split transcatheter mitral valve anchoring stent (10) and a transcatheter artificial biological mitral valve (20), wherein the shape and structure of the transcatheter mitral valve anchoring stent (10) are matched with the mitral valve real structure after the patient image data is subjected to three-dimensional reconstruction, the transcatheter mitral valve anchoring stent (10) is firstly delivered to the mitral valve position of the patient to be released and deformed, and the transcatheter artificial biological mitral valve (20) is in personalized precise alignment and coaptation with tissues on the mitral valve position of the patient and under the petals; the transcatheter artificial biological mitral valve (20) is delivered into the transcatheter mitral valve anchoring stent (10) to be released, the transcatheter artificial biological mitral valve (20) is released and deformed and expanded to a functional state, the transcat

Abstract: A bifunctional nucleoside hydrogel is formed by dissolving isoguanosine, guanosine and a borate in water or an aqueous solution and then crosslinking same. The bifunctional nucleoside hydrogel integrates a carrier and a drug effect and has a significant inhibitory effect on the activity of tumor cells, and in particular has a significant inhibitory effect on the activity of cells related to lung cancer, glioma, osteoma, colon cancer, breast cancer, oral squamous cell carcinoma and tongue squamous cell carcinoma, of which the inhibitory effect on the activity of cells related to oral squamous cell carcinoma is the best. Therefore, the bifunctional nucleoside hydrogel has potential application prospects in preparing anti-tumor drugs, and particularly, same can provide a new approach for treating oral squamous cell carcinoma.

Abstract: A method for chromium removal from post-tanning wastewater includes the following steps: (a) mixing pretreated post-tanning wastewater with an induction reagent to allow an induction reaction; and (b) adjusting a pH of a mixture obtained after the induction reaction to higher than 7.0 for precipitation; where the induction reagent includes a soluble metal salt. In the treatment method of the present disclosure, pretreated post-tanning wastewater is mixed with an induction reagent, a small amount of neutral chromium complexes remaining in the wastewater are converted into cationic chromium complexes under the action of the induction reagent (that is, a charge property of the chromium complex is changed), and then a pH is adjusted for precipitation to remove chromium, which greatly improves the removal efficiency of chromium in wastewater.

Abstract: A urinary system catheter is covered by an ethanol extract of propolis on a surface of the urinary system catheter. The EEP is used as a coating material of the urinary system catheter to prepare an antimicrobial urinary system catheter. The EEP serving as a surface coating can enhance surface hydrophilicity of the urinary system catheter, and clinical operation of the urinary system catheter is facilitated. Meanwhile, the EEP serving as the surface coating can prevent a bacterial biofilm from being formed on the surface of the urinary system catheter, thereby possessing antimicrobial and anti-infective effects, and a high anti-scab capacity. In addition, propolis is a natural substance, has the advantages of good biocompatibility and low cost, and is suitable for mass production. The urinary system catheter prepared by using the EEP as the coating has a good application prospect.

Abstract: A system for monitoring internal corrosion of a pipeline based on radio-frequency identification (RFID), including a magnetizing device, a RFID tag sensor, and a reader. The magnetizing device is placed on the pipeline, and includes an armature, a first permanent magnet, a first pole shoe, a second permanent magnet and a second pole shoe. The RFID tag sensor is placed on the pipeline, and at the same side with the magnetizing device. The reader is in wireless communication connection with the RFID tag sensor through a reader antenna.

Abstract: A rolling and sliding adaptive device for guiding and fixing a drill pipe includes a mounting platform, where the mounting platform is provided with a through hole for the drill pipe to pass through. Multiple rolling and sliding support mechanisms are arranged around the through hole. The rolling and sliding support mechanisms each include a support seat. The support seat is provided with a contact element telescopic and swingable on the support seat. A telescopic drive mechanism is provided between the contact element and the support seat. The contact elements on the multiple rolling and sliding support mechanisms form a funnel-shaped structure with a large upper part and a small lower part around the through hole. The rolling and sliding adaptive device is used on a deep in-situ high-fidelity coring calibration platform for accurate positioning of an assembly process of a multi-section drill pipe bin.

Abstract: A deep learning-based MRI examination and diagnosis system for displacement of a temporomandibular joint disc includes: an acquisition unit, configured to acquire a human head MRI image; a labeling unit, configured to obtain temporomandibular joint area images based on the human head MRI image, and label the temporomandibular joint area images to obtain a training set, the temporomandibular joint area images being classified into images in which a joint disc is in normal and abnormal positions in open and closed states; and a diagnosis unit, configured to construct a first temporomandibular joint disc displacement diagnosis model, and train a first jaw joint disc displacement classification model based on the training set to obtain a second temporomandibular joint disc displacement diagnosis model which is configured to classify and recognize temporomandibular joint area images to be diagnosed, and output a temporomandibular joint disc displacement examination and diagnosis result.

Abstract: Some embodiments of the disclosure provide methods for calculating carbon footprints of leather chemical materials. In some examples, the method includes: determining a calculation range of a carbon footprint of a leather chemical material in a life cycle as “cradle to gate”; determining a system boundary, a functional unit, and cut-off criteria for the carbon footprint of the leather chemical material in the life cycle; dividing the carbon footprint into a raw chemical obtaining process, a production process of the leather chemical material, and a waste disposal process within the system boundary; determining a carbon footprint calculation model for the leather chemical material according to resource consumption and environmental emission of each process; collecting and determining a quantity and a value required by each parameter in the carbon footprint calculation model; and calculating the carbon footprint of the leather chemical material using the carbon footprint calculation model.

Abstract: Some embodiments of the disclosure provide accounting methods for carbon footprints of leather products. In some examples, the accounting method includes the following steps: firstly, determining a system boundary for a carbon footprint in a life cycle of a leather product; dividing the carbon footprint into a raw material production and transportation stage, a leather product production stage, and a leather product transportation and distribution stage within the system boundary for the leather product; determining carbon emission source inventories of the stages and emission factors thereof in combination with process and flow characteristics of the stages, and then constructing carbon emission accounting models of the stages, and calculating carbon footprint data of the stages, and, finally, obtaining the carbon footprint of the leather product.

Abstract: A quaternary ammonium salt compound of formula I is fast-acting and has a long-term local anaesthetic effect after a single administration, the sensory nerve block time being longer than the motor nerve block time, has both a long-acting local anaesthetic effect and a selective local anaesthetic effect, and also significantly reduces the side effects of quaternary ammonium salt compounds with the structural features of surfactants and is highly safe; thus, the compound of formula I and the pharmaceutically acceptable salt thereof can be used for the preparation of saft drugs having a long-term local anaesthetic effect and a selective local anaesthetic effect

Abstract: An automatic detection function-integrated detection apparatus includes a drill rod and an elastic water storage bag; two sides of the drill rod are a head region and a tail region, respectively; an interior of the drill rod has a water supply channel, a side wall of the drill rod is provided with a first channel, and a first valve is disposed in the first channel. The automatic detection function-integrated detection apparatus and method for the water flowing fractured zone may complete the detection of the water flowing fractured zone while drilling, and thus the labor intensity of workers may be reduced.

Abstract: An internal blowout-prevention gas-retaining connector has a body mounted at the bottom of a drill pipe. The body includes a valve pipe section and a connecting pipe section arranged from top to bottom. The bottom of the valve pipe section is inserted into the top of the connecting pipe section. The blowout-prevention valve seat is provided at a bottom end of the valve pipe section while a blowout-prevention valve bonnet is provided on a bottom surface of the valve pipe section. The edge of the blowout-prevention valve bonnet is rotatably connected to a bottom surface edge of the valve pipe section. A torsion spring is provided on a bottom surface of the blowout-prevention valve bonnet. One end of the torsion spring is connected to the bottom surface of the blowout-prevention valve bonnet while the other end is connected to the inner wall of the connecting pipe section.

Abstract: A method for differentiable architecture search based on a hierarchical grouping mechanism includes: obtaining a target dataset; selecting a set number of normal cells and two reduction cells; enabling the reduction cells to be located at ? and ? of all cells, respectively, and then concatenating all cells to form an initial search network; training the initial search network to optimize a cost function to complete a one-level search or a two-level search, wherein in the one-level search, control weight parameters are shared by the inter-group operations and are shared by the intra-group operations among the cells; and in the two-level search, the control weight parameters are shared by the inter-group operations and are not shared by the intra-group operations, obtaining normal cells and reduction cells based on the one-level search or the two-level search; and constructing a target network using the normal cells and the reduction cells.

Abstract: A soot-suppression flame-separation combustion device for combustion calorimetry and in-situ free radicals monitoring is mainly composed of a premixed combustion gas guide tube, an inner flame generating seat, an oxidation flame separation guide, and a sample combustion chamber. The inner flame generating seat is arranged in the premixed combustion gas guide tube, the oxidation flame separation guide is arranged on the premixed combustion gas guide outlet end of the premixed combustion gas guide tube, the sample combustion chamber is a cavity arranged inside the oxidation flame separation guide, and the oxidation flame separation guide is evenly arranged with at least 4 oxidation flame separation guide paths in a manner of surrounding the sample combustion chamber. The combustion device utilizes the special structure of the oxidation flame separation guide to suppress the generation of smoke and limit the smoke particles to a specific combustion area.

Abstract: A microwave heating device with reflection protection belongs to a technical field of microwave applications. A first port of a circulator is connected to a microwave generator, and a second port of the circulator is connected to a microwave transmission device. A water load comprises a waveguide section, a metamaterial structure layer and the absorption tube. One end of the waveguide section is connected to a third port of the circulator, and the other end is sealed by a metal plate. The metamaterial structure layer is arranged in the waveguide section, and a center of the metamaterial structure layer has an accommodation space. The absorption tube is arranged along an internal wall of the accommodation space with a spiral extending form. Both ends of the absorption tube penetrate the waveguide section, and coolant flows in the absorption tube. Relative dielectric constants of the metamaterial structure layer gradually increase.

Abstract: A glycosyl donor represented by formula (I) is used for preparing an S-glycoside compound represented by formula (III), an O-glycoside compound represented by formula (V), and a C-glycoside compound represented by formula (V). The glycosyl donor is a raw material in the preparation of O-glycoside, S-glycoside, and C-glycoside compounds by means of a free radical reaction, most of which have a special ? configuration.