Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced ...Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and scaffolds.However,these sophisticated techniques can be timeconsuming,labor-intensive,and expensive.Moreover,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma patients.In this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a patient.These modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during surgery.The proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or segmentation.This algorithm can generate both patient-specific and average bone models.Additionally,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or images.The algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM process.Guidelines and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects.展开更多
Nerve guidance channels are limited by lack of topographical guidance：Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct en...Nerve guidance channels are limited by lack of topographical guidance：Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct end-to-end suture repair,is possible.The problem arises when there is significant segmental loss,which can occur following trauma as well as oncological procedures.展开更多
Lithium(Li)metal is regarded as one of the most promising anode candidates for next-generation batteries due to its extremely high specific capacity and low redox potential.However,its application is still hindered by...Lithium(Li)metal is regarded as one of the most promising anode candidates for next-generation batteries due to its extremely high specific capacity and low redox potential.However,its application is still hindered by the uncontrolled growth of dendritic Li and huge volume fluctuation during cycles.To address these issues,flexible and self-supporting three-dimensional(3D)interlaced Ndoped carbon nanofibers(NCNFs)coated with uniformly distributed 2D ultrathin NiCo_(2)S_(4)nanosheets(denoted CNCS)were designed to eliminate the intrinsic hotspots for Li deposition.Physicochemical dual effects of CNCS arise from limited surface Li diffusivity with a higher Li affinity,leading to uniform Li nucleation and less random accumulation of Li,as confirmed by ab initio molecular dynamics simulations.Due to the unique structure,exchange current density is reduced significantly and metallic Li is further contained within the interspace between the NCNF and NiCo_(2)S_(4)nanosheets,preventing the formation of dendritic Li.The symmetric cell with a Li/CNCS composite anode shows a long-running lifespan for almost 1200 h,with an exceptionally low and stable overpotential under 1mA cm^(-2)/1 mAh cm^(-2).A full cell coupled with a LiFePO4 cathode at a low N/P ratio of 2.45 shows typical voltage profiles but more significantly enhanced performance than that of a LiFePO4 cathode coupled with a bare Li anode.展开更多
文摘Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and scaffolds.However,these sophisticated techniques can be timeconsuming,labor-intensive,and expensive.Moreover,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma patients.In this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a patient.These modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during surgery.The proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or segmentation.This algorithm can generate both patient-specific and average bone models.Additionally,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or images.The algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM process.Guidelines and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects.
文摘Nerve guidance channels are limited by lack of topographical guidance：Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct end-to-end suture repair,is possible.The problem arises when there is significant segmental loss,which can occur following trauma as well as oncological procedures.
基金Natural Sciences and Engineering Research Council of Canada,Grant/Award Numbers:Alliance‐Alberta Innovates Program/ALLRP‐561137‐20,Discovery Grant Program/RGPIN‐2020‐05184University of Alberta Future Energy Systems。
文摘Lithium(Li)metal is regarded as one of the most promising anode candidates for next-generation batteries due to its extremely high specific capacity and low redox potential.However,its application is still hindered by the uncontrolled growth of dendritic Li and huge volume fluctuation during cycles.To address these issues,flexible and self-supporting three-dimensional(3D)interlaced Ndoped carbon nanofibers(NCNFs)coated with uniformly distributed 2D ultrathin NiCo_(2)S_(4)nanosheets(denoted CNCS)were designed to eliminate the intrinsic hotspots for Li deposition.Physicochemical dual effects of CNCS arise from limited surface Li diffusivity with a higher Li affinity,leading to uniform Li nucleation and less random accumulation of Li,as confirmed by ab initio molecular dynamics simulations.Due to the unique structure,exchange current density is reduced significantly and metallic Li is further contained within the interspace between the NCNF and NiCo_(2)S_(4)nanosheets,preventing the formation of dendritic Li.The symmetric cell with a Li/CNCS composite anode shows a long-running lifespan for almost 1200 h,with an exceptionally low and stable overpotential under 1mA cm^(-2)/1 mAh cm^(-2).A full cell coupled with a LiFePO4 cathode at a low N/P ratio of 2.45 shows typical voltage profiles but more significantly enhanced performance than that of a LiFePO4 cathode coupled with a bare Li anode.
