Adeno-associated virus (AAV) is a relatively safe and efficient vector for gene therapy. However, due to its 4.7-kb limit of cargo, SpCas9-mediated base editors cannot be packaged into single AAV vector, which hinders their clinical application. The development miniature becomes an urgent need. Un1Cas12f1 class II V-F-type CRISPR-Cas protein with only 529 amino acids. Although has been engineered editor in mammalian cells, the base-editing efficiency less than 10%, limits therapeutic...

This contribution deals with the complex temperature profiles that are generated by welding process in intersection region of thick walled, cylinder-cylinder junctions. These affect material microstructure, mechanical properties and residual stresses. Knowledge thermal history distributions thus critical developing control schemes for acceptable stress to improve in-service component behavior. A comprehensive study three-dimensional a stainless steel tee branch junction during multipass is...

This paper attempts to apply microplasma powder deposition (MPPD) for solid freeform fabrication (SFF). The relationship between the geometric features of deposited layers and welding parameters is investigated. arc length controlled through monitoring voltage. microstructure properties are analysed. experimental results show that MPPD process a promising welding-based SFF technology capable building relatively small-size parts with low cost. result functionally graded components by shown as well.

Precracked 304 stainless steel (304SS) compact tension (CT) specimens repaired by laser with addition of different weight fractions nano-tungsten carbide (nano-WC) were studied to investigate the effects nano-WC on fracture behavior and microstructure. Crack open displacements (CODs) measured a digital image correlation (DIC) system compared among treatments. Microstructures examined scanning electron microscopy (SEM) equipped an energy dispersive spectrometer (EDS). The results indicate...

Welded, thick-walled piping intersections are widely used in many engineering applications including the offshore and nuclear power industries. These components often fabricated by multipass welding, which inevitably introduces undesirable residual stresses. In this paper, weld-induced stresses a intersection were predicted using validated, full three dimensional, sequentially coupled thermomechanical finite element modeling technique. The moving heat source was simulated imposing body flux...

Recently, many different types of artificial discs have been introduced to persevere the biomechanical behavior cervical spine. This study compares single- and double-level disc arthroplasty, that is "Prestige LP Mobi-C" on index adjacent segment. A three-dimension finite element model C2-C7 was developed validated. In single-level prostheses, Prestige or Mobi-C implanted in segment C5-C6, while arthroplasty integrated at both segments C4-C5 C5-C6 FE model. The intact prosthesis-modified...

Crude oil is one of the most important energy sources in world and contains a lot paraffin wax. At higher temperatures, wax dissolved crude an equilibrium state. However, when temperature lower than precipitation wax, will precipitate, crystallize, form three-dimensional network structure, which have great impact on transportation oil. In engineering, waxy usually transported by adding pour point depressants. Pour depressant molecules can significantly improve crystallization behavior This...

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil gas, shipbuilding industries amongst others. These usually fabricated by multipass welding. The latter process is known induce residual stresses at fabrication stage, which can have severe adverse effects on in-service behavior of such critical components. It thus desirable if distributions be predicted well advance welding execution. This paper presents a...

Abstract Cracks generated by a wire electric discharge machining on compact tension specimens are first repaired high powered laser beam with different weight fractions of nano‐WC added at the crack tip. Digital image correlation method combined J ‐integral theory is used to measure and calculate ‐integrals specimens. Fracture properties compared studied. The residual stress after being was also studied analyze feasibility evaluate fracture parts. It found that influence can be neglected...

Traditional wind turbine inspection mainly relies on manual inspection, which has the advantages of intuitive and reliable feedback, but only task is easily affected by weather natural environment, as make it difficult to be carried out occasionally. It necessary introduce rapid development UAV autonomous technology for tasks. However, faces modeling problem caused stop position turbines, Additionally, route planning based experience operators. The above reasons guarantee efficiency. In...

WEI JIANG gratefully acknowledge financial support from the China Scholarship Council under Grants 99821129 and National Science Foundation of under Grants 59935110.

Purpose The non-stationary operational wind loads vary in time and site has remarkable effect on turbine drive train. purpose of this paper is to determine the effects class 3 7 life two-wind are described by average speed weight factor two variables energy generation train studied. Design/methodology/approach load distribution method used calculate stress range cycles for 7. To rise force train, cycle proposed. fatigue damage model studied with respect influence different speeds shear then...

Abstract Compact tension specimens with prefabricated cracks are repaired by laser micro/nano materials added at the crack tip. Different combinations of parameters, i.e., power, spot diameter and heating time, were applied to investigate their effects on microstructures fracture properties specimens. J-integrals calculated according digital image correlation (DIC) measurements, examined using scanning electron microscopy (SEM). When suitable parameters used, homogeneous compact equiaxed...

The biomechanical effects of intervertebral discs and facet joints degeneration on the cervical spine are essential to understanding mechanisms spinal disorders improve pathological clinical treatment. In this study, a progressively degenerated C5-C6 segment human lower determined by detailed simulation disc degeneration. A asymmetric three-dimension intact finite element model was developed using computed tomography scan data (C3-C7). then modified at build three models, such as mild,...