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Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines, the epidemic prevention and control are still challenging. Here, we employ a capsid and antigen structure engineering (CASE) strategy to manufacture an adeno-associated viral serotype 6-based vaccine (S663V-RBD), which expresses trimeric receptor binding domain (RBD) of spike protein fused with a biological adjuvant RS09. Impressively, the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months. Compared to the licensed BBIBP-CorV (Sinopharm, China), a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type, C.37 (Lambda) and B.1.617.2 (Delta). More interestingly, the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid. Given its effectiveness, the CASE-based S663V-RBD may provide a new solution for the current and next pandemic.
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For the transportation process of rescuing wounded personnel on naval vessels, a new type of shoulder type exoskeleton stretcher for individual soldier was designed in this paper. The three-dimensional model of the shoulder type exoskeleton stretcher for individual soldier was constructed using three dimensional modeling software. Finite element analysis technique was employed to conduct statics simulation, modal analysis, and transient dynamics analysis on the designed exoskeleton stretcher. The results show that the maximum stress of the exoskeleton stretcher for walking on flat ground is 265.55 MPa, which is lower than the allowable strength of the fabrication material. Furthermore, the overall deformation of the structure is small. Modal analysis reveals that the natural frequency range of the exoskeleton stretcher under different gait conditions is 1.96 Hz to 28.70 Hz, which differs significantly from the swing frequency of 1 Hz during walking. This indicates that the designed structure can effectively avoid resonance. The transient dynamics analysis results show that the maximum deformation and stress of exoskeleton stretcher remain within the safety range, which meets the expected performance requirements. In summary, the shoulder type exoskeleton stretcher for individual soldier designed in this study can solve the problem of requiring more than 2 people to carry for the existing stretcher, especially suitable for narrow spaces of naval vessels. The research results of this paper can provide a new solution for the rescue of wounded personnel on naval vessels.
Subject(s)
Humans , Stretchers , Military Personnel , Shoulder , Exoskeleton Device , Walking , Gait , Biomechanical PhenomenaABSTRACT
Objective To design a novel biodegradable intestinal anastomosis stent and explore the relationship between pressure distance and biomechanical properties of the anastomosis, so as to provide new ideas and methods for compression anastomosis of intestinal tissues. Methods A compression anastomosis stent was designed for reconstruction of intestinal tissues, and the finite element model of compression anastomosis of intestinal tissues was established to investigate the relationship between pressurized distance (2, 1.6, 1.2, 0.8 mm) and tissue stress of the stent. The anastomosis effect of intestinal tissue under different pressurized distances was analyzed by the test of tear-off force and burst pressure. Results Biomechanical properties of the intestinal anastomosis were the best when the pressurized distance was 1.2 mm, and its maximum tensile strength reached 0.77 MPa. The tear-off force and burst pressure of tissues were (25.80±1.82) N and (12.30±0.26) kPa, respectively. The optimal intestinal anastomosis was achieved when tissues were compressed to 60% of the original thickness. Conclusions The biodegradable intestinal stent designed in this study can successfully achieve compression anastomosis of intestinal tissues, which provides theoretical references for the development and application of novel biodegradable compression anastomosis devices.
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Objective:To design a new type of assistive chopsticks for the hand disorders, such as hand weakness and poor fine movement, etc. Methods:The assistive chopsticks were palm-control operative, integrated structure designed, and bending stamping processing technology was adopted. The key parts such as the bends and joint, holding parts were improved. The prototype was tested with finite element analysis and mechanical testing, and used on trial by a three years old boy. Results:The gripping force needed was related to the bending radius, material, section size and holding position. It required less dexterity and force for particular fingers, and was not easy to drop down. They could bounce off automatically and were suitable for left hand. Conclusion:The new type of assistive chopsticks may help the patients with hand dysfunction to have meals with chopsticks, to improve the quality of life. However, it is also suitable for Westerners with less experience.
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Objective To compare and analyze the mechanical performance of a new biodegradable stent and a common stent and their effects on treating the stenotic vessels. Methods Using finite numerical simulation, the new stent and the common stent were implanted into vessels with a diameter stenosis of 30%, and their support performance and influences on reshaping the stenotic vessels were investigated. Results The radial recoiling ratio and dog-boning ratio of the new stent were decreased by 26.6% and 34.7%, respectively, compared with the common stent. Besides, the stenotic vessel deployed with the new stent recoiled less and had a flatter and larger lumen. Conclusions Compared with the common stent, the new stent has stronger scaffold performance and a better therapeutic effect on stenotic vessels. The new stent with stronger scaffold performance is highly expected to be an alternative choice in interventional surgeries.
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Objective To analyze the mechanical properties of bone tissue engineering scaffolds with different pore structure and porosity, and improve the mechanical properties of scaffolds by changing pore structure. Methods Square pore, spherical pore and cylindrical pore with different porosities from 55% to 75% were established by SolidWorks software, and the surface-volume ratio of different structures was calculated. The stress distribution and equivalent compression modulus of different scaffolds were obtained by ANSYS Workbench software. According to the stress distribution results, the scaffold with rectangular pore structure and cuboid element structure was improved instead of square pores. Results With the increase of porosity, the surface-volume ratio of the three structures increased. For the same porosity, the surface-volume ratio of square pores and spherical pores was larger, while that of cylindrical pores was the smallest. The modulus and porosity of the three structures were approximately linear. The modulus of the square pore and the cylindrical pore were similar. The stress analysis on the square pore and two improved structures with 60% porosity showed that for the two improve structures, the wall stress on 4 edges parallel to the direction of applied stresses could be reduced by 15%. Conclusions The surface-volume ratio and mechanical property of square pores were more advantageous than spherical pores and cylindrical pores with the same porosity, and the two improved structures could improve the mechanical properties of square pores. The two improved pores enriched the structure of tissue engineering scaffolds. The research findings provide the mechanical references for their clinical application.
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Los centros de cirugía ambulatoria han contribuido al progreso de esta cirugía y se caracterizan por ser eficientes, productivos, rentables y generar alta satisfacción. Construir un centro de cirugía ambulatoria requiere constituir un equipo multidisciplinario encargado de desarrollar un proyecto que evalúe la viabilidad económica, seleccione el tipo de centro a construir, determine el tamaño y el diseño del centro y defina la dotación de personal; con esta información se realiza la evaluación económica final que decide la factibilidad de construir el centro. Organizar el inicio de actividades y el funcionamiento de este servicio requiere determinar horarios, modalidad de trabajo, flujos de circulación y funciones del personal, a través de protocolos que definan, describan y coordinen todos los procesos clínicos y administrativos involucrados desde la indicación de la cirugía hasta el alta del paciente. La eficiencia del pabellón quirúrgico es determinante en el funcionamiento de un centro de cirugía ambulatoria. Varios factores contribuyen a la eficiencia de pabellón, y el más crítico de estos es el tiempo entre cirugías o tiempo de recambio de pacientes, el cual es factible de optimizar. La cirugía ambulatoria es una modalidad de trabajo quirúrgico que requiere un servicio clínico propio, adecuadamente planificado, diseñado y organizado para lograr sus objetivos y ventajas.
Ambulatory surgery centers have contributed to the progress of ambulatory surgery and they are characterized by its efficiency, productivity and to produce high satisfaction. To build an outpatient surgery center a multidisciplinary team should be responsible to develop a project that to assess the economic viability, to select the type of center, to determine the size and the design of center and to set de staffing; with this information the final economic evaluation that decide the feasibility to build the center must be performed. To organize the launch activities and the operation of this service requires determining schedules, working mode, traffic flows and staff functions through protocols that to define, to describe and to coordinate all clinic and administrative process involved from the surgery indication to the patient discharge. The operating room efficiency is determining factor in the ambulatory surgery center functioning. Several factors contribute to the operating room efficiency, the most critical of which is the time between surgical procedures o turnover time and this time is feasible to optimize. Ambulatory surgery is a mode of surgical work requiring its own clinical service properly planned, designed and organized to achieve its objectives and advantages.
Subject(s)
Operating Rooms/organization & administration , Surgicenters/organization & administration , Efficiency, Organizational , Ambulatory Surgical ProceduresABSTRACT
Objective To design a real-time oxygen generation and supply device for ambulances and to carry out finite element simulated analysis and performance evaluation .Methods Based on the working principles of pressure swing adsorption (PSA) and oxygen pneumatic compression technology ,the structural components and technological processes of an oxygen generation and compression unit as well as an oxygen filling and supply unit were built .The integrated structure of the device was designed by Solidworks .The static structure of the oxygen generation and compression unit was analyzed by ANSYS.Modal analysis of the circuit board was also conducted .The performance of the prototype was evaluated .Results Wtih a stable structure and reliable circuitry , the device could produce and fill oxygen automatically at the flow of 5.0 L/min, concentration of 94.0%, and pressure of 13.0 MPa.Conclusion This device can produce , fill and supply oxygen automatically,and the goal of design is achieved .
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Radionuclide hypoxia imaging has become an indispensable core of tumor diagnosis. Nitroimidazole derivatives have been extensively used as the hypoxia imaging agents in preclinical and clinical research. It is the key to design the ideal structure for promising agents. The type and quantity of nitroimidazole, the linker structure and chiral may have an impact on the imaging results. The characteristics of the imaging agents including single electron reduction potential (SERP), oil-water partition coefficient (log P) and pharmacokinetics are also the key factors. In this review, we highlight the factors for hypoxia imaging, providing clues for the structure design of new agents.