Optical tissue clearing enables rapid,precise and comprehensive assessment of three-dimensional morphology in experimental nerve regeneration research

Morphological analyses are key outcome assessments for nerve regeneration studies but are historically limited to tissue sections.Novel optical tissue clearing techniques enabling three-dimensional imaging of entire organs at a subcellular resolution have revolutionized morphological studies of the brain.To extend their applicability to experimental nerve repair studies we adapted these techniques to nerves and their motor and sensory targets in rats.The solvent-based protocols rendered harvested peripheral nerves and their target organs transparent within 24 hours while preserving tissue architecture and fluorescence.The optical clearing was compatible with conventional laboratory techniques,including retrograde labeling studies,and computational image segmentation,providing fast and precise cell quantitation.Further,optically cleared organs enabled three-dimensional morphometry at an unprecedented scale including dermatome-wide innervation studies,tracing of intramuscular nerve branches or mapping of neurovascular networks.Given their wide-ranging applicability,rapid processing times,and low costs,tissue clearing techniques are likely to be a key technology for next-generation nerve repair studies.All procedures were approved by the Hospital for Sick Children’s Laboratory Animal Services Committee(49871/9)on November 9,2019.

Three-dimensional anthropometry in periorbital region

Anthropometry can analyze the size,weight,and proportion of the human body objectively and quantitatively to supplement the visual assessment.Various non-invasive three-dimensional(3D)anthropometric techniques have been applied to assess soft tissues’3D morphology in the clinical practice.Among them,non-invasive stereophotogrammetry and laser scanning techniques are becoming increasingly popular in craniofacial surgery and plastic surgery.They have been applied for craniofacial growth estimation and morphometric investigation,genetic and acquired malformation diagnosis,as well as orthodontic or surgical treatment arrangement and outcome evaluation.However,few studies have been published for assessing the 3D morphology of soft tissues in the periorbital region.This paper reviews the studies involving the application and evaluation of the increasingly popular 3D photogrammetry in the periorbital region.These studies proposed detailed and standardized protocols for three-dimensionally assessing linear,curvilinear,angular,as well as volumetric measurements,and verified its high reliability in the periorbital region(even higher than caliper-derived direct measurements).In the future,reliable and accurate 3D imaging techniques,as well as standardized analyzing protocols,may find applications in following up morphological growth,preoperatively diagnosing and assessing patient periorbital conditions,planning surgical procedures,postoperatively evaluating treatment outcomes of a specific procedure,and comparing the differences in surgical results between various procedures,studies,as well as populations.

Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method

In this paper, the authors present airflow field characteristics of human upper airway and soft palate movement attitude during breathing. On the basis of the data taken from the spiral computerized tomography images of a healthy person and a patient with Obstructive Sleep Apnea-Hypopnea Syndrome （OSAHS）, three-dimensional models of upper airway cavity and soft palate are reconstructed by the method of surface rendering. Numerical simulation is performed for airflow in the upper airway and displacement of soft palate by fluid-structure interaction analysis. The reconstructed threedimensional models precisely preserve the original configuration of upper airways and soft palate. The results of the pressure and velocity distributions in the airflow field are quantitatively determined, and the displacement of soft palate is presented. Pressure gradients of airway are lower for the healthy person and the airflow distribution is quite uniform in the case of free breathing. However, the OSAHS patient remarkably escalates both the pressure and velocity in the upper airway, and causes higher displacement of the soft palate. The present study is useful in revealing pathogenesis and quantitative mutual relationship between configuration and function of the upper airway as well as in diagnosingdiseases related to anatomical structure and function of the upper airway.

Study on the new shell bolting and shotcrete support and its application in soft rock tunnels

A new kind of tunnel support was put forward on the basis of the anchor spraysupport principle. The mechanics of the new three-dimensional steel bar shotcrete liningsupport was studied and the structure's internal forces were analyzed. The model experiment was done relying on the industrial test. The conclusion of numerical calculationsproved that the ANSYS program is reasonable and creditable. It was compared to otherkinds of support that are commonly used in soft rock tunnels. The technique and economiccontrasts of the typical tunnel with support three-dimensional steel bar were completed.

Soft pneumatic actuators by digital light processing combined with injection-assisted post-curing

The soft robotics display huge advantages over their rigid counterparts when interacting with living organisms and fragile objects.As one of the most efficient actuators toward soft robotics,the soft pneumatic actuator(SPA)can produce large,complex responses with utilizing pressure as the only input source.In this work,a new approach that combines digital light processing(DLP)and injection-assisted post-curing is proposed to create SPAs that can realize different functionalities.To enable this,we develop a new class of photo-cross linked elastomers with tunable mechanical properties,good stretchability,and rapid curing speed.By carefully designing the geometry of the cavities embedded in the actuators,the resulting actuators can realize contracting,expanding,flapping,and twisting motions.In addition,we successfully fabricate a soft self-sensing bending actuator by injecting conductive liquids into the three-dimensional(3D)printed actuator,demonstrating that the present method has the potential to be used to manufacture intelligent soft robotic systems.

The quaternion beam model for hard-magnetic flexible cantilevers

The recently developed hard-magnetic soft(HMS)materials manufactured by embedding high-coercivity micro-particles into soft matrices have received considerable attention from researchers in diverse fields,e.g.,soft robotics,flexible electronics,and biomedicine.Theoretical investigations on large deformations of HMS structures are significant foundations of their applications.This work is devoted to developing a powerful theoretical tool for modeling and computing the complicated nonplanar deformations of flexible beams.A so-called quaternion beam model is proposed to break the singularity limitation of the existing geometrically exact(GE)beam model.The singularity-free governing equations for the three-dimensional(3D)large deformations of an HMS beam are first derived,and then solved with the Galerkin discretization method and the trustregion-dogleg iterative algorithm.The correctness of this new model and the utilized algorithms is verified by comparing the present results with the previous ones.The superiority of a quaternion beam model in calculating the complicated large deformations of a flexible beam is shown through several benchmark examples.It is found that the purpose of the HMS beam deformation is to eliminate the direction deviation between the residual magnetization and the applied magnetic field.The proposed new model and the revealed mechanism are supposed to be useful for guiding the engineering applications of flexible structures.

Synthesis of Hollow Three-Dimensional Channels LiNi_(0.5)Mn_(1.5)O_4 Microsphere by PEO Soft Template Assisted with Solvothermal Method

A appropriate size with three-dimension(3 D) channels for lithium diffusion plays an important role in constructing highperforming LiNi_(0.5)Mn_(1.5)O_4(LNMO) cathode materials, as it can not only reduce the transport path of lithium ions and electrons, but also reduce the side effects and withstand the structural strain in the process of repetitive Li~+ intercalation/deintercalation. In this work, an e fficient method for designing the hollow LNMO microsphere with 3 D channels structure by using polyethylene oxide(PEO) as soft template agent assisted solvothermal method is proposed. Experimental results indicate that PEO can make the reagents mingle evenly and nucleate slowly in the solvothermal process, thus obtaining a homogeneous distribution of carbonate precursors. In the final LNMO products, the hollow 3 D channels structure obtained by the decomposition of PEO and carbonate precursor in the calcination can provide abundant electroactive zones and electron/ion transport paths during the charge/discharge process, which benefits to improve the cycling performance and rate capability. The LNMO prepared by adding 1 g PEO possesses the most outstanding electrochemical performance, which presented an excellent discharge capacity of 143.1 mAh g~(-1) at 0.1 C and with a capacity retention of 92.2% after 100 cycles at 1 C. The superior performance attributed to the 3 D channels structure of hollow microspheres, which provide uninterrupted conductive systems and therefore achieve the stable transfer for electron/ion.

北京地区正常面部软组织不对称性的三维测量研究

目的应用数字化立体摄影测量系统进行正常面部软组织不对称性的三维测量,获得面部软组织在三维方向上的不对称向量。方法选择40例正常成人进行面部软组织不对称性的三维测量,计算面部软组织在三维方向上的不对称向量。结果男性组和女性组都是右侧面部较大,但男女无显著性差异;面部不对称量都是在x轴上分布最多;面部越靠面下部的点和越靠外侧面的点,其不对称量越大。结论用三维摄影测量的分析方法显示面部中下部的不对称性更为明显;三维立体摄影测量是较好的研究面部软组织不对称性的方法。

面部软组织数字化立体摄影测量原理

目的 :阐述应用立体摄影测量系统进行面部软组织三维测量的原理。方法 :应用数码相机和数字化立体摄影测量的方法进行面部软组织三维测量。结果 :面部软组织立体摄影测量系统可以达到足够高的面部三维测量精度。结论

正常面部软组织三维测量

目的 :应用数字化立体摄影测量系统进行正常面部软组织的三维测量。方法 :应用数码相机和我们研制的一套数字化立体摄影测量硬件和软件系统 ,按照一定纳入标准选择 30例正常进行面部软组织三维测量 ,并分男性组与女性组进行对照。结果 :分别建立了正常男性组与女性组的正常值 ,并得到男性组与女性组对照统计分析结果。结论 :本研究应用了一种新的面部软组织三维测量系统对正常面部软组织进行三维测量 。

汉族青年女性口唇形态与面型的相关性研究

目的：测量汉族青年女性唇部软组织正常值,探讨唇部软组织正常值间相关性以及与面型的关系.方法：选择2012 ～ 2013级在校女学生（共70名,年龄18～19岁;均为汉族）,采用面部软组织直接测量口唇各部高度均值、口列宽度均值、正面三庭均值、面宽均值、形态面高和容貌面高均值、内眦距离均值.结果：面部软组织直接测量获得口唇各部高度均值（唇高：3.45±0.608、上唇高：1.95±0.317、上白唇高：1.29±0.326、上红唇高：0.67±0.201、下唇高：1.55±0.349、下白唇高：0.79±0.336、下红唇高：0.77±0.199、上下红唇高：1.48±0.297）cm、口列宽度均值（4.37±0.341）cm、正面三庭均值（上庭：5.92±0.770、中庭：5.75±0.427、下庭6.07±0.607）cm、面宽均值（14.40±1.174）cm、形态面高（11.85±1.144）cm和容貌面高（18.59±1.234）cm均值、内眦距离均值（3.32±0.339）cm.结论：①建立青年女性口唇形态测量相关指标的正常参考值;②口裂宽与内眦距离（P=0.005）、上唇高（P=0.000）、唇高（P=0.007）有正相关（P＜0.01）,唇形态改变的趋势是越厚越宽,越窄越薄;③上唇高（P=0.043）、下唇高（P=0.004）和唇高（P=0.011）与上庭有正相关;④唇高与唇各部高度（除下红唇高无相关）均呈正相关,且与上唇高和下唇高相关性显著（P=0.000）;上唇高与唇各部高度（除下白唇高无相关）均呈正相关,且与上红唇高、上下红唇高、上白唇高及唇高相关性显著（P=0.000）,而与下红唇高有相关性（P=0.002）,且上红唇高对上唇高影响较上白唇高影响大;下唇高与下白唇高（P=0.000）、唇高（P=0.000）相关性显著,颏唇沟位置对下唇高度影响大;上红唇高与上下红唇高相关性显著（P=0.000）;（P＜0.01）;⑤唇各部高度和宽度与容貌面高、形态面高和面宽无相关性（P＞0.05）.⑥以上唇形态正常参考值及相关性对整形外科提供形态学基础。

正常人群面部软组织三维测量与X线头影测量的相关性分析

目的 比较正常的面部软组织三维测量与X线头影测量结果。方法 应用面部软组织数字化立体摄影测量与X线头影测量对标准正常进行面部软组织三维测量 ,并进行相关性分析。结果 面部软组织三维测量项目与对应的X线头影测量项目具备相关性。结论 面部软组织三维测量结果能够部分的反映其下硬组织的情况。

软组织扩张术后皮肤组织形态计量学改变

本文对６例额部皮肤软组织扩张术后皮瓣和８例正常人额部皮肤组织进行形态计量学分析及超微结构观察，探讨软组织扩张后“额外”皮肤组织的来源及形态计量学指标的改变。结果表明，扩张后表皮层数、表皮细胞面积及表皮、真皮厚度的检测值均明显高于正常对照组（Ｐ＜０．０１），而且真皮内血管数目增多。提示，软组织扩张后，表皮细胞增殖及真皮内胶原纤维合成增加是“额外”皮肤来源的形态学基础。

面部软组织的三维测量系统的开发和应用

目的 开发一套面部软组织三维测量系统 ,以融合测量与图像技术作为一种客观的手段 ,协助医生为患者提供更好的服务。方法 利用 2个CCD摄像头、识别标志点的实时硬件以及测量软件 ,集成一套三维测量系统。结果 该系统能对面部软组织进行高效、简便的三维测量 ,而且对受检者无损伤。结论 本系统是获取面部三维信息的一种有效手段 。

面部软组织的三维测量分析

目的 研究操作者确定标志点的可重复性 ,并获取一批恒牙初期少年的面部测量数据。方法 由同一名操作者在对 8名男性完成采像后擦去标记 ,进行重新定点测量 ,比较 14个标志点至鼻根点空间线距的前后结果。对 2 0名恒牙初期少年进行面部软组织的三维测量。结果 前后 2次定点测量的结果无统计学差异。恒牙初期少年各测量项目的性别比较中 ,17个有差异者主要集中在与下面高相关的项目上。结论 本研究所选用的标志点有明显的解剖特征 ,操作者能较好地掌握定点标准。

Application of three-dimensional culture systems to study mammalian spermatogenesis, with an emphasis on the rhesus monkey （Macaca mulatta）

In vitro culture of spermatogonial stem cells （SSCs） has generally been performed using two-dimensional （2D） culture systems; however, such cultures have not led to the development of complete spermatogenesis. It seems that 2D systems do not replicate optimal conditions of the seminiferous tubules （including those generated by the SSC niche） and necessary for spermatogenesis. Recently, one of our laboratories has been able to induce proliferation and differentiation of mouse testicular germ cells to meiotic and postmeiotic stages including generation of sperm in a 3D soft agar culture system （SACS） and a 3D methylcellulose culture system （MCS）. It was suggested that SACS and MCS form a special 3D microenvironment that mimics germ cell niche formation in the seminiferous tubules, and thus permits mouse spermatogenesis in vitro. In this review, we （1） provide a brief overview of the differences in spermatogenesis in rodents and primates, （2） summarize data related to attempts to generate sperm in vitro, （3） report for the first time formation of colonies/clusters of cells and differentiation of meiotic （expression of CREM-1） and postmeiotic （expression of acrosin） germ cells from undifferentiated spermatogonia isolated from the testis of prepubertal rhesus monkeys and cultured in SACS and MCS, and （4） indicate research needed to optimize 3D systems for in vitro primate spermatogenesis and for possible future application to man.

面部软组织三维测量系统的可靠性研究

目的 检验面部软组织三维测量系统的技术可靠性。方法 以石膏头像为研究对象 ,用系统在 15种不同条件下测量模型面部 9个点至鼻根点的距离 ,以用游标卡尺得到的测量结果为评判标准与前者比较。结果 两者的平均差值为 1.2 1mm ,误差率为 2 .0 9%。模拟头位变化的 8种状态中 ,仅在右转 10°时与标准相比有显著性差异。

Printable Kirigami-inspired Flexible and Soft Anthropomorphic Robotic Hand

We present a kirigami-inspired design scheme for a robotic hand by 3D printable folds and cuts.The unique contribution is the printable flexible hand,which provides flexibility and maneuverability that is unavailable in rigid robotic systems.The integration of sensors in the robotic system enables force adjustment for robotic systems applicable in the future.The experimental results have shown that this design can perform everyday tasks through grasping and pinching different items.The fingers can bend from 40 to 100 degrees.Furthermore,the direct printable kirigami cuts and folds from soft elastic printable materials have significant potential for prosthetic devices.The printable kirigami design framework opens the possibility for future developments and modifications in numerous robotic applications.

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.