3D Printed Anchoring Sutures for Permanent Shaping of Tissues

Sutures are one of the most widely used devices for adhering separated tissues after injury or surgery. However, most sutures require knotting, which can create a risk of inflammation, and can act as mechanically weak points that often result in breakage and slipping. Here, an anchoring suture is presented with a design that facilitates its propagation parallel to the suturing direction, while maximizing its resistive force against the opposite direction of external force to lock its position in tissues. Different microstructures of suture anchors are systematically designed using orthogonal arrays, and selected based on shape factors associated with mechanical strength. 3D printing is used to fabricate different types of hollow microstructured suture anchors, and optimize their structure for the effective shaping of tissues. To define the structural design for fixing tissues, the maximum force required to pull 3D printed anchors in different directions is examined with tissues. The tissue reshaping function of suture anchors is further simulated ex vivo by using swine ear, nose, and skin, and bovine muscle tendon. This study provides advantages for building functional sutures that can be used for permanently reshaping tissues with enhanced mechanical strength, eliminating the need for knotting to improve surgical efficiency.     

计算导热系数的新公式

在传统的一维传热模型下导热系数的计算公式误差较大.本文通过建立试样内部的三维传热模型,更为科学地考虑了侧壁散热的影响,推导出了计算导热系数的新公式.以橡胶为研究材料进行实验,证明了新公式的合理性.引入影响因子P来衡量侧壁散热对系统的影响程度,分析得到P值随着试样厚度增加而增大.     

A three-dimensional autonomous nonlinear dynamical system modelling equatorial ocean flows

We investigate a nonlinear three-dimensional model for equatorial flows, finding exact solutions that capture the most relevant geophysical features: depth-dependent currents, poleward or equatorial surface drift and a vertical mixture of upward and downward motions.     

High‐resolution resist for screen printing: application to direct fabrication of Ag circuit

High‐resolution screen printing was devised. New resist formulation contains a base polymer, which consists of acid‐labile tetrahydropyranyl‐protected carboxylic acid, hydroxyl, and methacrylic functions. As crosslinkers, multifunctional acrylates were employed. Photoacid generators were used for pattern formation. A 10‐µm feature size of resist on a screen plate was obtained on irradiation at 365 nm and followed by development on a stainless steel screen. Post‐exposure curing improved the mechanical characteristics of the resist patterns. A 13‐µm feature size silver circuit was successfully printed on poly(ethylene terephthalate) film without defect. Copyright © 2011 John Wiley & Sons, Ltd.     

Direct fabrication of copper patterns by reactive inkjet printing

Reactive inkjet printing (RIP) was applied to fabricate arbitrary copper (Cu) patterns. RIP prints reactive inks which can provide desired materials after the reaction on a substrate. Here, Cu precursors and reducing agents were dissolved together in one solution as a printable ink instead of conventional Cu nanoparticle inks. The prepared reactive ink was applied to the RIP method to provide dot arrays, lines, and films of Cu. The synthesis of Cu was confirmed to occur successfully by thorough analysis. The RIP method can reduce the process cost and resolve critical drawbacks of the conventional inkjet printing such as a nozzle clogging problem. Furthermore, utilizing reactive precursor inks broadens the choice of materials that can be processed by inkjet printing.     

Eyewear-style three-dimensional endoscope derived from microstructured polymer fiber with the function of image transmission

A method of fabricating multi-core polymer image fiber is proposed.Image fiber preform is fabricated by stacking thousands of polymer fibers each with a 0.25-mm diameter orderly in a die by only one step.The preform is heated and stretched into image fiber with an outer diameter of 2mm.Then a portable eyewear-style three-dimensional(3D) endoscope system is designed,fabricated,and characterized.This endoscopic system is composed of two graded index lenses,two pieces of 0.35-m length image guide fibers,and a pair of oculars.It shows good ?exibility and portability,and can provide the depth information accordingly.     

带螺旋支撑杆的同轴磁绝缘传输线三维数值模拟的实现

依据实际器件尺寸, 建立了带螺旋支撑杆的同轴磁绝缘传输线三维数值模拟模型; 选取合适的二极管阴阳极间距作为传输线负载; 设置相应的模拟参数对其进行模拟. 将模拟结果与实验数据进行对比, 证明了模拟的可靠性; 并结合相应的实验数据, 分析了同轴磁绝缘传输线在加入螺旋支撑结构后 对其传输效率的影响.     

增强辉光放电等离子体离子注入的三维PIC／MC模拟

采用三维粒子模拟／蒙特卡洛模型自洽地模拟了增强辉光放电等离子体离子注入过程中离子产生和注入,获得了放电空间的离子总数、电势分布、等离子体密度分布和离子入射剂量等信息．模拟结果表明,5μs时鞘层达到稳定扩展,15μs时离子的产生与注入达到平衡,证实了增强辉光放电等离子体离子注入能在一定条件下实现白持的辉光放电．注入过程中,在点状阳极正下方存在一个高密度的等离子体区域,证实了电子聚焦效应．除靶台边缘外,离子的注入速率稳定且入射剂量均匀．脉冲负偏压提高时注入速率增加但入射剂量的均匀性变差．     

贝诺酯与牛血清白蛋白位点选择性结合的分子光谱研究

采用荧光光谱、紫外可见光谱、同步荧光光谱及三维荧光光谱等分子光谱方法,研究了生理条件下贝诺酯(BEN)与牛血清白蛋白(BSA)的相互作用。结果表明,BEN对BSA的内源荧光有显著的猝灭作用,猝灭机理为动态猝灭,二者之间的作用力类型以疏水作用为主,BEN与BSA发生反应后,使BSA的疏水环境极性增强,疏水性减弱,荧光强度降低。测得的表观结合常数和结合位点数分别是1 050 L·mol^-1和0.88,同时测得了焓变(ΔH)、熵变(ΔS)和自由能变(ΔG)等热力学参数。同步荧光和三维荧光光谱的结果表明,BEN使BSA的构象发生改变。利用荧光特异性位点探针DA和DP,通过竞争结合实验,监测BEN与BSA的结合位点,测得了位点Ⅰ和位点Ⅱ的表观结合常数分别为4 300 L·mol^-1和21 200 L·mol^-1,表明BEN与BSA优先在位点Ⅱ结合。