Phase II Clinical Study of Three-Dimensional Printed Coplanar Template Combined with CT-Guided Percutaneous Core Needle Biopsy of Pulmonary Nodules in Elderly Patients

Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .

Method for visualizing the shear process of rock joints using 3D laser scanning and 3D printing techniques

This study presents a visualized approach for tracking joint surface morphology.Three-dimensional laser scanning(3DLS)and 3D printing(3DP)techniques are adopted to record progressive failure during rock joint shearing.The 3DP resin is used to create transparent specimens to reproduce the surface morphology of a natural joint precisely.The freezing method is employed to enhance the mechanical properties of the 3DP specimens to reproduce the properties of hard rock more accurately.A video camera containing a charge-coupled device(CCD)camera is utilized to record the evolution of damaged area of joint surface during the direct shear test.The optimal shooting distance and shooting angle are recommended to be 800 mm and 40?,respectively.The images captured by the CCD camera are corrected to quantitatively describe the damaged area on the joint surface.Verification indicates that this method can accurately describe the total sheared areas at different shear stages.These findings may contribute to elucidating the shear behavior of rock joints.

A combination of digital design and three-dimensional printing to assist treatment of thoracolumbar compression fractures using percutaneous kyphoplasty

Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tures.Methods:From January 2018 to August 2020,we obtained data of 99 patients diagnosed thoracolumbar compression fractures.These patients were divided into control group(n=50)underwent traditional PKP surgery,and observation group(n=49)underwent preoperative digital design combined with 3D printing model assisted PKP treatment.The clinical efficacy was evaluated with five parameters,including operation time,number of intraoperative radiographs,visual analogue scale(VAS)score,Cobb Angle change,and high compression rate of injured vertebrae.Results:There were statistically significant differences of operation time and number of intraoperative radio graphs between the two groups(P<0.05).For VAS score,Cobb Angle change and vertebral height compression rate,all of these three parameters were significantly improved when the patients accepted surgery teatment in two groups(P<0.05).However,there were no significant differences between control group and observation group for these three parameters either before or after surgery(P>0.05).Conclusions:Through the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation,the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized,the number of intraoperative radiographs was reduced,the operation time was shortened and the operation efficiency was improved.

Application and prospective of 3D printing in rock mechanics: A review

This review aims to discuss the application and development of three-dimensional printing(3DP) technology in the field of rock mechanics and the mechanical behaviors of 3D-printed specimens on the basis of various available printing materials.This review begins with a brief description of the concepts and principles associated with 3DP, and then systematically elaborates the five major applications of 3DP technology in the field of rock mechanics, namely, the preparation of rock(including pre-flawed rock) specimens, preparation of joints, preparation of geophysical models, reconstruction of complex rock structures, and performance of bridging experimental testing and numerical simulation.Meanwhile, the mechanical performance of 3D-printed specimens created using six different printing materials, such as polymers, resin,gypsum, sand, ceramics, and rock-like geological materials, is reviewed in detail.Subsequently, some improvements that can make these 3D-printed specimens close to natural rocks and some limitations of 3DP technology in the application of rock mechanics are discussed.Some prospects that are required to be investigated in the future are also proposed.Finally, a brief summary is presented.This review suggests that 3DP technology, especially when integrated with other advanced technologies, such as computed tomography scanning and 3D scanning, has great potential in rock mechanics field.

Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology

In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.

Inner damage identification and residual strength assessment of a 3D printed tunnel with marble-like cementitious materials using piezoelectric transducers

Quantitative damage identification of surrounding rock is important to assess the current condition and residual strength of underground tunnels.In this work,an underground tunnel model with marble-like cementitious materials was first fabricated using the three-dimensional(3D)printing technique and then loaded to simulate its failure mode in the laboratory.Lead zirconate titanate piezoelectric(PZT)transducers were embedded in the surrounding rock around the tunnel in the process of 3D printing.A 3D monitoring network was formed to locate damage areas and evaluate damage extent during loading.Results show that as the load increased,main cracks firstly appeared above the tunnel roof and below the floor,and then they coalesced into the tunnel boundary.Finally,the tunnel model was broken into several parts.The resonant frequency and the peak of the conductance signature firstly shifted rightwards with loading due to the sealing of microcracks,and then shifted backwards after new cracks appeared.An overall increase in the root-mean-square deviation(RMSD)calculated from conductance signatures of all the PZT transducers was observed as the load(damage)increased.Damage-dependent equivalent stiffness parameters(ESPs)were calculated from the real and imaginary signatures of each PZT at different damage states.Satisfactory agreement between equivalent and experimental ESP values was achieved.Also,the relationship between the change of the ESP and the residual strength was obtained.The method paves the way for damage identification and residual strength estimation of other 3D printed structures in civil engineering.

The application of 3D printing in the development of RECIST standard for evaluating tumor efficacy

Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial structure into a 3D imaging structure.In recent years,the technology has been widely used in numerous areas,including head and neck surgery,orthopedics,and bio-medicinal research.This article uses examples of 3D printed tumor models to develop Response Evaluation Criteria In Solid Tumors(RECIST)standards to evaluate the changes in tumors.RECIST standard is currently recognized as the standard for assessment of chemotherapy.Under the RECIST standard,changes occurring in tumors before and after the surgery,are evaluated.The assessment depends upon a CT evaluation of the changes in the lesions with the largest diameters.In addition,the disease progression and stability of remission is also assessed.Three-dimensional printing technology is more intuitive in the evaluation of changes to human tumors following chemotherapy and targeted therapy.However,a few reports are available.

Control of electromechanical performance in 3D printing latticestructured BaTiO_(3) piezoelectric ceramics

Barium titanate(BaTiO_(3))piezoelectric ceramics with triply periodic minimal surface(TPMS)structures have been frequently used in filters,engines,artificial bones,and other fields due to their high specific surface area,high thermal stability,and good heat dissipation.However,only a limited number of studies have analyzed the effect of various parameters,such as different wall thicknesses and porosities of TPMS structures,on ceramic electromechanical performance.In this study,we first employed vat photopolymerization(VPP)three-dimensional(3D)printing technology to fabricate high-performance BaTiO_(3) ceramics.We investigated the slurry composition design and forming process and designed a stepwise sintering postprocessing technique to achieve a density of 96.3%and a compressive strength of 250±25 MPa,with the piezoelectric coefficient(d_(33))reaching 263 pC/N.Subsequently,we explored the influence of three TPMS structures,namely,diamond,gyroid,and Schwarz P,on the piezoelectric and mechanical properties of BaTiO_(3) ceramics,with the gyroid structure identified as exhibiting optimal performance.Finally,we examined the piezoelectric and mechanical properties of BaTiO_(3) ceramics with the gyroid structure of varying wall thicknesses and porosities,thus enabling the modulation of ceramic electromechanical performance.

3D printed silicon-based micro-lattices with ultrahigh areal/gravimetric capacities and robust structural stability for lithium-ion batteries

Nanostructured silicon anodes have shown extraordinary lithium storage properties for lithium-ion batteries(LIBs)but are usually achieved at low areal loadings(<1.5 mg·cm^(-2))with low areal capacity.Sustaining sound electrochemical performance at high loading requires proportionally higher ion/electron currents and robust structural stability in the thicker electrode.Herein,we report a three-dimensional(3D)printed silicon-graphene-carbon nanotube(3D-Si/G/C)electrode for simultaneously achieving ultrahigh areal/gravimetric capacities at high mass loading.The periodically arranged vertical channels and hierarchically porous filaments facilitate sufficient electrolyte infiltration and rapid ion diffusion,and the carbonaceous network provides excellent electron transport properties and mechanical integrity,thus endowing the printed 3D-Si/G/C electrode with fast electrochemical reaction kinetics and reversibility at high mass loading.Consequently,the 3D-Si/G/C with high areal mass loading of 12.9 mg·cm^(-2) exhibits excellent areal capacity of 12.8 mAh·cm^(-2) and specific capacity of 1007 mAh·g^(-1),respectively.In-situ optical microscope and ex-situ scanning electron microscope(SEM)confirm that the hierarchically porous filaments with interconnected carbon skeletons effectively suppress the volume change of silicon and maintain stable micro-lattice architecture.A 3D printed 3D-Si/G/C-1||3D-LiFePO_(4)/G full cell holds excellent cyclic stability(capacity retention rate of 78%after 50 cycles)with an initial Coulombic efficiency(ICE)of 96%.This work validates the feasibility of 3D printing on constructing high mass loading silicon anode for practical high energy-density LIBs.

3D printing of architectured graphene-based aerogels by cross-linking GO inks with adjustable viscoelasticity for energy storage devices

Three-dimensional(3D)functional graphenebased architecture with superior electrical conductivity and good mechanical strength has promising applications in energy storage and electrics.Viscoelasticity-adjustable inks make it possible to achieve desired 3D architectures with interconnected and continuous interior networks by microextrusion printing.In this work,ultra-low-concentration graphene oxide(GO)inks of~15 mg·ml-1 have been obtained and demonstrated in direct 3D printing with a facile cross-linking(direct ink writing).The rheological behavior of the GO strategy by cations,which is the lowest concentration to achieve direct ink writing inks,could be adjusted from 1×10^(4) to 1×10^(5) Pa·s^(-1) with different concentrations of cations due to strong cross-linking networks between GO sheets and cations.Meanwhile,the specific strength and electrical conductivity of 3D-printed graphene architecture are notably enhanced,reaching up to 51.7×10^(3) N·m·kg^(-1)and 119 S·m^(-1),which are superior to conventional graphene aerogels.Furthermore,3D printing graphene-based architecture assembled in micro-superc apacitor exhibits excellent electrochemical performance,which can be ascribed to the effective ion transportation through the interconnected networks.The strategy demonstrated is useful in the design of complex-shaped,graphene-based architectures for scalable manufacturing of practical energy storage applications.

3D printing CO_(2)-activated carbon nanotubes host to promote sulfur loading for high areal capacity lithium-sulfur batteries

Lithium-sulfur batteries(LSBs)have emerged as a promising high energy density system in miniaturized energy storage devices.However,serious issues rooted in large volume change(80%),poor intrinsic conductivity,“shuttle effect”of S cathode,and limited mass loading of traditional electrode still make it a big challenge to achieve high energy density LSBs in a limited footprint.Herein,an innovative carbon dioxide(CO_(2))assisted three-dimensional(3D)printing strategy is proposed to fabricate threedimensional lattice structured CO_(2)activated single-walled carbon nanotubes/S composite thick electrode(3DP S@CNTs-CO_(2))for high areal capacity LSBs.The 3D lattice structure formed by interwoven CNTs and printed regular macropores can not only act as fast electron transfer networks,ensuring good electronic conductivity of thick electrode,but is beneficial to electrolyte infiltration,effectively boosting ion diffusion kinetics even under a high-mass loading.In addition,the subsequent hightemperature CO_(2)in-situ etching can induce abundant nanopores on the wall of CNTs,which significantly promotes the sulfur loading as well as its full utilization as a result of shortened ion diffusion paths.Owing to these merits,the 3DP S@CNTs-CO_(2)electrode delivers an impressive mass loading of 10 mg·cm^(−2).More importantly,a desired attribute of linearly scale up in areal capacitance with increased layers is observed,up to an outstanding value of 5.74 mAh·cm^(−2),outperforming most reported LSBs that adopt strategies that physically inhibit polysulfides.This work provides a thrilling drive that stimulates the application of LSBs in new generation miniaturized electronic devices.

3D-printed mechanically strong and extreme environment adaptable boron nitride/cellulose nanofluidic macrofibers

Fibrous nanofluidic materials are ideal building blocks for implantable electrode,biomimetic actuator,wearable electronics due to their favorable features of intrinsic flexibility and unidirectional ion transport.However,the large-scale preparation of fibrous nanofluidic materials with desirable mechanical strength and good environment adaptability for practical use remains challenging.Herein,by fully taking advantage of the attractive mechanical,structural,chemical features of boron nitride(BN)nanosheet and nanofibrillated cellulose(NFC),a scalable and cost-effective three-dimensional(3D)printed macrofiber featuring abundant vertically aligned nanofluidic channels is demonstrated to exhibit a good combination of high tensile strength of 100 MPa,thermal stability of up to 230℃,ionic conductivity of 1.8×10^(−4)S/cm at low salt concentrations(<10^(−3)M).In addition,the versatile surface chemistry of cellulose allows us to stabilize the macrofiber at the molecular level via a facile postcross-linking method,which eventually enables the stable operation of the modified macrofiber in various extreme environments such as strong acidic,strong alkaline,high temperature.We believe this work implies a promising guideline for designing and manufacturing fibrous nanodevices towards extreme environment operations.

A novel 3D printed technology to construct a monolithic ultrathin nanosheets Co_(3)O_(4)/SiO_(2) catalyst for benzene catalytic combustion

In this study,a novel three-dimensional(3D)-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP(OMm=ordered macro–meso porous,AP=aluminum phosphate)monolithic catalyst was for the first time constructed successfully with the hierarchical Co-phyllosilicate ultrathin nanosheets growth on the surface of 3D printed ordered macropore–mesoporous SiO_(2)support.On the one hand,we discovered that the construction of ordered macropore–mesoporous structures is beneficial to the diffusion and adsorption of reactants,intermediates,and products.On the other hand,the formation of hierarchical Co-phyllosilicate ultrathin nanosheets could provide more active Co&+species,abundant acid sites,and active oxygen.The above factors are in favor of improving the catalytic performance of benzene oxidation,and then a 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst exhibited the superior catalytic activity.To explore the effect of catalysts structure and morphology,various Co-based catalysts were also constructed.Simultaneously,the 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst has excellent catalytic performance,water resistance,and thermal stability in the catalytic combustion of benzene due to the strong interactions between Co&+species and SiO_(2)in the phyllosilicate.Therefore,this study proposes a new catalyst synthesis method through 3D printing,and presents considerable prospects for the removal of VOCs from industrial applications.

3D-printed Lunar regolith simulant-based geopolymer composites with bio-inspired sandwich architectures

Over time,natural materials have evolved to be lightweight,high-strength,tough,and damage-tolerant due to their unique biological structures.Therefore,combining biological inspiration and structural design would provide traditional materials with a broader range of performance and applications.Here,the application of an ink-based three-dimensional(3D)printing strategy to the structural design of a Lunar regolith simulant-based geopolymer(HIT-LRS-1 GP)was first reported,and high-precision carbon fiber/quartz sand-reinforced biomimetic patterns inspired by the cellular sandwich structure of plant stems were fabricated.This study demonstrated how different cellular sandwich structures can balance the structure–property relationship and how to achieve unprecedented damage tolerance for a geopolymer composite.The results presented that components based on these biomimetic architectures exhibited stable non-catastrophic fracture characteristics regardless of the compression direction,and each structure possessed effective damage tolerance and anisotropy of mechanical properties.The results showed that the compressive strengths of honeycomb sandwich patterns,triangular sandwich patterns,wave sandwich patterns,and rectangular sandwich patterns in the Y-axis(Z-axis)direction were 15.6,17.9,11.3,and 20.1 MPa(46.7,26.5,23.8,and 34.4 MPa),respectively,and the maximum fracture strain corresponding to the above four structures could reach 10.2%,6.7%,5.8%,and 5.9%(12.1%,13.7%,13.6%,and 13.9%),respectively.

Friction and wear of textured surfaces produced by 3D printing

Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear. The most common methods for surface texatring are laser and injection molding. The 3D printing method is also used to build parts, patterns, and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster, more flexible, and less expensive than traditional techniques. To date, there has been no research on textured surfaces produced by 3D printing. Therefore, a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring. In this study, a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing. The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test. The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.

Perusing Piezoelectric Head Performance in a New 3-D Printing Design

Rapid prototyping (RP) is a computerized fabrication technology that additively builds highly complex three-dimensional physical objects layer by layer using data generated by computer, for example CAD or digital graphic. Three-dimensional printing (3DP) is one of such technologies that employ ink-jet printing technology for processing powder materials. During fabrication, a printer head is used to print a liquid on to thin layers of powder following the object’s profile as generated by the system computer. This work looks at redesigning 3DP machine, using piezoelectric demand-mode technology head in order to improve accuracy, surface finishing and color quality of constructed models. The layers created with aforesaid system are between 25 to 150 μm (steps of 25 μm).

A Voronoi diagram approach for detecting defects in 3D printed fiber-reinforced polymers from microscope images

Fiber-reinforced polymer(FRP)composites are increasingly popular due to their superior strength to weight ratio.In contrast to significant recent advances in automating the FRP manufacturing process via 3D printing,quality inspection and defect detection remain largely manual and inefficient.In this paper,we propose a new approach to automatically detect,from microscope images,one of the major defects in 3D printed FRP parts:fiber-deficient areas(or equivalently,resin-rich areas).From cross-sectional microscope images,we detect the locations and sizes of fibers,construct their Voronoi diagram,and employ-shape theory to determine fiber-deficient areas.Our Voronoi diagram and-shape construction algorithms are specialized to exploit typical characteristics of 3D printed FRP parts,giving significant efficiency gains.Our algorithms robustly handle real-world inputs containing hundreds of thousands of fiber cross-sections,whether in general or non-general position.

Lightweight 3D bioprinting with point by point photocuring

As photocrosslinkable materials,methacryloyl-modified hydrogels are widely used as bioinks in tissue engineering.Existing printing methods to use these hydrogels,including changing the viscosity of the material or mixing them with other printing components,have been explored,but their application has been limited due to low printing quality or high cost.In addition,the complex operation of bulky equipment restricts the application of these existing printing methods.This study presents a lightweight stereolithography-based three-dimensional(3D)bioprinting system with a smart mechanical and structural design.The developed bioprinter dimensions were 300 mm×300 mm×200 mm and it can be placed on a benchtop.The equipment has a mini bioink chamber to store a small amount of bioink for each printing.We systematically investigated the point-by-point curing process in the 3D bioprinting method,which can print mixed cells accurately and have good biocompatibility.Here,we provide a compact,low-cost stereolithography bioprinting system with excellent biocompatibility for 3D bioprinting with methacryloyl-modified hydrogels.It can be potentially used for drug screening,studying pathological mechanisms,and constructing biological disease models.

Advances in 3D printing of magnetic materials:Fabrication,properties,and their applications

Magnetic materials are of increasing importance for many essential applications due to their unique magnetic properties.However,due to the limited fabrication ability,magnetic materials are restricted by simple geometric shapes.Three-dimensional(3D)printing is a highly versatile technique that can be utilized for constructing magnetic materials.The shape flexibility of magnets unleashes opportunities for magnetic composites with reducing post-manufacturing costs,motivating the review on 3D printing of magnetic materials.This paper focuses on recent achievements of magnetic materials using 3D printing technologies,followed by the characterization of their magnetic properties,which are further enhanced by modification.Interestingly,the corresponding properties depend on the intrinsic nature of starting materials,3D printing processing parameters,and the optimized structural design.More emphasis is placed on the functional applications of 3D-printed magnetic materials in different fields.Lastly,the current challenges and future opportunities are also addressed.

Inkjet printing technology for increasing the I/O density of 3D TSV interposers

Interposers with through-silicon vias(TSVs)play a key role in the three-dimensional integration and packaging of integrated circuits and microelectromechanical systems.In the current practice of fabricating interposers,solder balls are placed next to the vias;however,this approach requires a large foot print for the input/output(I/O)connections.Therefore,in this study,we investigate the possibility of placing the solder balls directly on top of the vias,thereby enabling a smaller pitch between the solder balls and an increased density of the I/O connections.To reach this goal,inkjet printing(that is,piezo and super inkjet)was used to successfully fill and planarize hollow metal TSVs with a dielectric polymer.The under bump metallization(UBM)pads were also successfully printed with inkjet technology on top of the polymer-filled vias,using either Ag or Au inks.The reliability of the TSV interposers was investigated by a temperature cycling stress test(−40℃ to+125℃).The stress test showed no impact on DC resistance of the TSVs;however,shrinkage and delamination of the polymer was observed,along with some micro-cracks in the UBM pads.For proof of concept,SnAgCu-based solder balls were jetted on the UBM pads.