A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and invers...A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and inversion of possibly dense block diagonal matrices and significantly reduces user interaction.Validation results are presented from the application of SOMA to subsonic,compressible,and turbulent flow over an adiabatic flat plate.展开更多
Acoustoelastic coupling occurs when a hollow structure’s in-vacuo mode aligns with an acoustic mode of the internal cavity.The impact of this coupling on the total dynamic response of the structure can be quite sever...Acoustoelastic coupling occurs when a hollow structure’s in-vacuo mode aligns with an acoustic mode of the internal cavity.The impact of this coupling on the total dynamic response of the structure can be quite severe depending on the similarity of the modal frequencies and shapes.Typically,acoustoelastic coupling is not a design feature,but rather an unintended result that must be remedied as modal tests of structures are often used to correlate or validate finite element models of the uncoupled structure.Here,however,a test structure is intentionally designed such that multiple structural and acoustic modes are well-aligned,resulting in a coupled system that allows for an experimental investigation.First,coupling in the system is identified using a measure termed the magnification factor.Next,the structural-acoustic interaction is measured.Modifications to the system demonstrate the dependency of the coupling on changes in the mode shape and frequency proximity.This includes an investigation of several practical techniques used to decouple the system by altering the internal acoustic cavity,as well as the structure itself.These results show that acoustic absorption material effectively decoupled the structure while structural modifications,in their current form,proved unsuccessful.Readily available acoustic absorptive material was effective in reducing the coupled effects while presumably adding negligible mass or stiffness to the structure.展开更多
Over the last two decades,small activating RNAs(saRNAs)have quickly moved from discovery to clinical trials.Characterized as 20 nucleotide long,double stranded RNA,saRNAs have the unique ability to increase gene trans...Over the last two decades,small activating RNAs(saRNAs)have quickly moved from discovery to clinical trials.Characterized as 20 nucleotide long,double stranded RNA,saRNAs have the unique ability to increase gene transcription at the chromatin level.This therapeutic modality has great potential as a safe and redosable alternative to gene therapy by increasing target protein expression without changing the genetic sequence.We describe the successful in vivo saRNA delivery vectors and found that similar to small interfering RNA(siRNA)and mRNA targeting tissues outside the liver works best at the end of a needle.We highlight nanoparticle vectors and RNA-conjugates,where some success has been reported for non-hepatic delivery of saRNAaptamers.展开更多
基金The authors wish to express their appreciation to the reviewers for their helpful suggestions which greatly improved the presentation of this paper。
文摘A meshless and matrix-free fluid dynamics solver(SOMA)is introduced that avoids the need for user generated and/or analyzed grids,volumes,and meshes.Incremental building of the approximation avoids creation and inversion of possibly dense block diagonal matrices and significantly reduces user interaction.Validation results are presented from the application of SOMA to subsonic,compressible,and turbulent flow over an adiabatic flat plate.
文摘Acoustoelastic coupling occurs when a hollow structure’s in-vacuo mode aligns with an acoustic mode of the internal cavity.The impact of this coupling on the total dynamic response of the structure can be quite severe depending on the similarity of the modal frequencies and shapes.Typically,acoustoelastic coupling is not a design feature,but rather an unintended result that must be remedied as modal tests of structures are often used to correlate or validate finite element models of the uncoupled structure.Here,however,a test structure is intentionally designed such that multiple structural and acoustic modes are well-aligned,resulting in a coupled system that allows for an experimental investigation.First,coupling in the system is identified using a measure termed the magnification factor.Next,the structural-acoustic interaction is measured.Modifications to the system demonstrate the dependency of the coupling on changes in the mode shape and frequency proximity.This includes an investigation of several practical techniques used to decouple the system by altering the internal acoustic cavity,as well as the structure itself.These results show that acoustic absorption material effectively decoupled the structure while structural modifications,in their current form,proved unsuccessful.Readily available acoustic absorptive material was effective in reducing the coupled effects while presumably adding negligible mass or stiffness to the structure.
文摘Over the last two decades,small activating RNAs(saRNAs)have quickly moved from discovery to clinical trials.Characterized as 20 nucleotide long,double stranded RNA,saRNAs have the unique ability to increase gene transcription at the chromatin level.This therapeutic modality has great potential as a safe and redosable alternative to gene therapy by increasing target protein expression without changing the genetic sequence.We describe the successful in vivo saRNA delivery vectors and found that similar to small interfering RNA(siRNA)and mRNA targeting tissues outside the liver works best at the end of a needle.We highlight nanoparticle vectors and RNA-conjugates,where some success has been reported for non-hepatic delivery of saRNAaptamers.
