3D printing

摘要： In this study,a new type of 3 D printed living biological hydrogel was developed by integrating lactic acid bacteria(LAB)into biocompatible and non-toxic polymer materials.Interestingly,the living materials loaded with LAB can be freeze-dried and reused for more than 100 times.The bio-hydrogel can be used to co-culture different LAB and keep its fermentation performance stable in long-term use.The release kinetics model and response surface method were used to simulate and optimize the bacteria release mode in the bio-hydrogel.The results show that the release of bacteria from hydrogel is regulated by the coupling of Fickian diffusion and polymer swelling.The stability of LAB hydrogel was evaluated by reuse experiments.The images of confocal microscopy and scanning electron microscope showed that the bacteria with high cell viability were distributed in the hydrogel and intact structure of the living hydrogel was maintained after 100 times of reuse as yoghurt starter.In conclusion,the 3 D printed LAB bio-hydrogel developed in this study has the advantage of reuse and sustainability,which is expected to open up a new way for the preparation of food culture starter.

摘要： It is desirable to fabricate materials with adjustable physical properties that can be used in different industrial applications.Since the property of a material is highly dependent on its inner structure,the understanding of structure–property correlation is critical to the design of engineering materials.3D printing appears as a mature method to effectively produce micro-structured materials.In this work,we created different stainless-steel microstructures by adjusting the speed of 3D printing and studied the relationship between thermal property and printing speed.Our microstructure study demonstrates that highly porous structures appear at higher speeds,and there is a nearly linear relationship between porosity and printing speed.The thermal conductivity of samples fabricated by different printing speeds is characterized.Then,the correlation between porosity,thermal conductivity,and scanning speed is established.Based on this correlation,the thermal conductivity of a sample can be predicted from its printing speed.We fabricated a new sample at a different speed,and the thermal conductivity measurement agrees well with the value predicted from the correlation.To explore thermal transport physics,the effects of pore structure and temperature on the thermal performance of the printed block are also studied.Our work demonstrates that the combination of the 3D printing technique and the printing speed control can regulate the thermophysical properties of materials.

摘要： Physical forces,such as magnetic and mechanical stimulation,are known to play a significant role in the regulation of cell response.In the present study,a biomimetic regeneration patch was fabricated using E-jet 3 D printing,which integrates mechanical and magnetic stimulation in a biocompatible"one-pot reaction"strategy when combined with a static magnetic field(SMF).The magneto-based therapeutic regeneration patch induced myoblasts to form aligned and multinucleated myotubes,regulated the expression of myogenic-related genes,and activated the p38αmitogen-activated protein kinase pathway via the initiation of myogenic differentiation.To validate the efficiency of the proposed strategy,the regeneration patch was implanted into mice and exposed to a suitable SMF,which resulted in significantly enhanced in vivo skeletal muscle regeneration.The findings demonstrated that appropriate external physical stimulation provides a suitable biophysical microenvironment that is conducive to tissue regeneration.The method used in the present study represents a promising technique to induce the regeneration of damaged skeletal muscle tis sue.

摘要： The current study is directed to the rapidly developing field of inorganic material 3D object production at nano-/micro scale.The fabrication method includes laser lithography of hybrid organic-inorganic materials with subsequent heat treatment leading to a variety of crystalline phases in 3D structures.In this work,it was examined a series of organometallic polymer precursors with different silicon(Si)and zirconium(Zr)molar ratios,ranging from 9:1 to 5:5,prepared via sol-gel method.All mixtures were examined for perspective to be used in 3D laser manufacturing by fabricating nano-and micro-feature sized structures.Their spatial downscaling and surface morphology were evaluated depending on chemical composition and crystallographic phase.The appearance of a crystalline phase was proven using single-crystal X-ray diffraction analysis,which revealed a lower crystallization temperature for microstructures compared to bulk materials.Fabricated 3D objects retained a complex geometry without any distortion after heat treatment up to 1400°C.Under the proper conditions,a wide variety of crystalline phases as well as zircon(ZrSiO_(4)-a highly stable material)can be observed.In addition,the highest new record of achieved resolution below 60 nm has been reached.The proposed preparation protocol can be used to manufacture micro/nano-devices with high precision and resistance to high temperature and aggressive environment.

摘要： The sieving and enrichment of rare tumor cells from large-volume pleural effusion(PE)samples is a promising technique for cell-based lung tumor diagnosis and drug tests,which features high throughput and recovery,purification,as well as viability rates of rare target cells as the prerequisites for high sensitivity,specificity,and accuracy of tumor cell analysis.In this paper,we propose a three-dimensional(3 D)sieving method for rare tumor cell enrichment,which effectively eliminates the"dead zones"in traditional two-dimensional(2 D)cell filters with a dimension-raising strategy to satisfy the requirements mentioned above.The prototype device was combined with a funnel-shaped holder,a flexible micropore membrane in the middle,and a3 D spiral fluid channel covered on the membrane as a three-layer ice-creaming cone composite structure.Driven by gravity alone,the device performed as follows:(1)20-fold throughput compared with the 2 D commercial planee hich was up to 20 mL/min for a threefold dilution of whole blood sample;(2)high recovery rates of 84.5%±21%,86%±25%,83%±14%for 100,1000,and 10000 cells/mL,respectively,in 30 mL phosphate buffer saline(PBS)sample,and a 100%positive detection rate in the case of≤5 A549 cells in 1 mL PBS;(3)a typical purification rate of 85.5%±9.1%;and(4)a viability rate of>93%.In the demonstration application,this device effectively enriched rare target cells from large volumes(>25 mL)of clinical pleural effusions.The following results indicated that tumor cells were easy-to-discover in the enriched PE samples,and the proliferation capability of purified cells was(>4.6 times)significantly stronger than that of unprocessed cells in the subsequent 6-day culture.The above evaluation indicates that the proposed easily reproducible method for the effective execution of rare cell enrichments and assays is expected to become a practical technique for clinical cell-based tumor diagnosis.

摘要： Hydrogels with stimuli-responsive capabilities are gaining more and more attention nowadays with prospective applications in biomedical engineering,bioelectronics,microrobot,etc.We develop a photothermal responsive hydrogel based on N-isopropylacrylamide that achieved a fast and reversible deformation manipulated only by near-infrared(NIR)light.The hydrogel was fabricated by the projection micro stereolithography based 3D printing technique,which can rapidly prototype complex 3D structures.Furthermore,with the variation of the grayscale while manufacturing the hydrogel,the deformation of the hydrogel structure can be freely tuned within a few seconds by losing and absorbing water through adjusting the intensity and the irradiation direction of the NIR light,showing a potential application in ultra-fast object grabbing and transportation.The present study provides a new method for designing ultrafast photothermal responsive hydrogel based microrobot working in water.

摘要： This paper presents an optimization method to compute the rotary axes of a 5-axis FDM printer whose A-and C-axes have large deviations relative to the x-and z-directions.The optimization model is designed according to the kinematic model in which a point rotates around a spatial line in the machine coordinate system of the printer.The model considers the A-and C-axes as two spatial lines.It is a two-object optimization model including two aspects.One is that the sum of deviations between the measured and computed points should be small;the other is that the deviations should be uniformly distributed for every measured point.A comparison of the new optimization method with conventional error-compensation methods reveals that the former has higher location accuracy.Using the optimized AC axes,5-axis 3D printing paths are planned for some complex workpieces.Data analysis and printing samples show that the optimized AC axes satisfy 5-axes FDM printing requirements for nozzles with a diameter of 1.0 mm.

摘要： Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.

摘要： Objective: To carry out a 3D vector reconstruction of the muscles of the ventral region of the neck from anatomical sections of the “Korean Visible Human” for educational purposes. Materials and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kgs. The anatomical sections were made in 2010 after an MRI and a CT scan. A special saw (cryomacrotome) made it possible to make cuts 0.2 mm thick on the frozen body, i.e. 5960 cuts. Sections numbered 1500 to 2000 (or 500 cuts covering the neck) were used for our study. A segmentation by manual contouring of each anatomical element of the anterior neck region was done using Winsurf version 3.5 software on a laptop PC running Windows 7 equipped with an 8 gigabyte RAM. Results: We modeled the sternocleidomastoid muscles, the supra-hyoid muscles, the infra-hyoid muscles and the muscle structures of the anterior neck region, the aero-digestive axis of the anterior neck region and the vasculo-nervous axis of the neck. This model is easily manipulated using the Acrobat 3Dpdf interface. Each item accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. This vector model has been integrated into the Diva3d virtual dissection table, a new educational tool used by universities and medical schools to learn anatomy. This model was also uploaded to the Sketchfab? website and 3D printed using an ENDER? pro 3 printer. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the anterior neck region and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

摘要： As a promising manufacturing technology,three-dimensional(3D)printing technology is widely used in the medical field.In the treatment of osteoarticular defects,the emergence of 3D printing technology provides a new option for the reconstruction of functional articular surfaces.At present,3D printing technology has been used in clinical applications such as models,patient-specific instruments(PSIs),and customized implants to treat joint defects caused by trauma,sports injury,and tumors.This review summarizes the application status of 3D printing technology in the treatment of osteoarticular defects and discusses its advantages,disadvantages,and possible future research strategies.

摘要： 本发明涉及一种制备1，3，5-三乙基-2，4，6-三氢-2，4，6-三乙基氨基-1，3，5-三氮杂-2，4，6-三硅代环己烷的方法，其中三氯硅烷与乙胺在溶剂中反应。

摘要： 本发明揭示了三维指示方法。在本发明的三维指示方法中，根据在预定的检测面上使用输入笔的笔尖进行了指示时的指示位置的二维坐标、以及对前述输入笔的笔尖施加的压力即笔压或者进行了持续指示的时间或前述输入笔具有的操作单元的操作，指示表现在显示装置上的三维空间内的期望点。并且，在本发明的三维指示方法中，根据前述输入笔的笔尖或者进行了持续指示的时间或前述输入笔具有的操作单元的操作，使显示在前述三维空间内的三维指针的深度方向的坐标变化来显示在显示装置上。

摘要： 用于制备锗‑硅‑层(Ge‑Si)或作为甲硅烷基团(SiH

摘要： 向粉末床照射波束来进行层叠造型的三维层叠造型装置的施工异常检测系统，基于粉末床的表面形状的测定结果，在满足粉末床的相对于基准位置的平均高度从第一规定范围脱离的第一条件、以及粉末床的高度的偏差从第二规定范围脱离的第二条件中的至少一者的情况下，判定为发生了粉末床的铺设异常。

摘要： 本发明涉及一种制备1，3，5-三乙基-2，4，6-三氢-2，4，6-三乙基氨基-1，3，5-三氮杂-2，4，6-三硅代环己烷的方法，其中三氯硅烷与乙胺在溶剂中反应。

摘要： 三维数据编码方法对分别位于多个区域中的某一个区域的多个三维点按每个区域进行编码(S9401)，生成连接信息，该连接信息是基于多个区域中的规定的区域与多个区域中的规定的区域以外的多个其他区域的关系而生成的，且包含(i)表示固有地分配给多个区域的每一个的值的瓦片信息、以及(ii)通过瓦片信息表示规定的区域与其他区域具有关联性的关联信息(S9402)，生成包含所生成的连接信息和被编码的多个三维点的比特流(S9403)。

摘要： 三维数据编码方法决定将表示三维点群的点群数据分割为多个时的分割数据单位、和分割前的点群数据单位中的至少一方的编码后的编码数据的第1最大比特数(S9681)，通过以满足所决定的第1最大比特数的方式对分割点群数据而成的多个分割数据或分割前的点群数据进行编码，从而生成比特流(S9682)，比特流包含表示第1最大比特数的第1比特数信息。

摘要： 一种对具有层级结构的多个三维点进行编码的三维数据编码方法，使用第1三维点的周围的1个以上的第2三维点的第2位置信息，设定用于计算第1三维点的第1位置信息的预测值的2个以上的预测模式中的1个预测模式(S9781)；计算被设定的预测模式的预测值(S9782)；计算作为第1位置信息与计算出的预测值的差分的预测残差(S9783)；生成包含被设定的预测模式和预测残差的第1比特流(S9784)；在设定中，基于第1三维点的层级结构的深度，设定预测模式。

摘要： 使用参数对多个三维点的多个属性信息进行编码(S9241)，生成包含被编码的多个属性信息以及参数的比特流(S9242)，多个属性信息分别属于1个以上的阶层中的某一个且属于1个以上的区域中的某一个，参数根据成为编码的对象的属性信息所属的阶层以及区域来确定，比特流中包含的参数包含规定的基准值、按每个阶层确定的第1差分值、以及按每个区域确定的第2差分值。

摘要： 一种三维数据编码方法，判定多个第1节点中包含的有效节点的数量即第1有效节点数是否为预先确定的第1阈值以上，所述多个第1节点属于点群数据中包含的多个三维点的N(N为2以上的整数)叉树结构中的对象节点的上位层，所述有效节点是包含有三维点的节点(S9541)，在第1有效节点数为第1阈值以上的情况下(S9541的“是”)，对对象节点的属性信息进行第1编码，所述第1编码包含使用了多个第2节点的预测处理，所述多个第2节点包含对象节点的父节点，并且与父节点属于同一阶层(S9542)，在第1有效节点数小于第1阈值的情况下(S9541的“否”)，对对象节点的属性信息进行第2编码，所述第2编码不包含使用了多个第2节点的预测处理(S9543)。