一种Ti-6Al-4V功能梯度网状结构的设计与压缩性能

通过电子束选区熔化制造具有高孔隙率的多孔Ti-6Al-4V结构,旨在用于替代人类松质骨.开放的网状结构能够提供骨组织向内生长的空间,因此能更好的起到固定的作用.利用计算机辅助设计（CAD）,制备一种低密度（0.78 g/cm3）,高孔隙率（82%）,弹性模量为2.7 GPa的功能梯度网状结构.结果表明,制备的功能梯度网状结构与致密件相比,具有和松质骨接近的的弹性模量,能够有效的避免应力屏蔽效应.此外,通过增加层与层之间的厚度,可以有效的防止裂纹在网状结构中快速扩展,提高安全性.此结构的屈服强度为62 MPa,试样的组织中的细小的α’相有利于提高植入物的寿命.     

Fabrication of highly bioactive zirconia ceramics via grain-boundary activation for dental implants

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics with outstanding mechanical properties and aesthetic origins are expected to be used in dental implant applications. However, tetragonal zirconia ceramics are not bioactive, which affect the osseointegration and reliability as dental implant materials. Herein, in this study, Y-TZP ceramics were modified by grain-boundary activation via coating a bioactive glass (BG) sol with different content on the crystal surfaces of zirconia powder and followed by being gelled, dried, granulated, low-temperature treated, molded and sintered at 1450°C for 3 h in air. The effects of BG content on the morphology, phase compositions, mechanical properties, in vitro mineralization ability and cell biological properties of the bioactivity modified Y-TZP ceramics were evaluated. The BG additive did not affect the tetragonal–monoclinic phase transformation of ZrO₂. However, the addition of BG decreased the flexural strength of the modified Y-TZP ceramics compared to that of Y-TZP. The in vitro mineralization results showed that a homogeneous apatite layer was produced on the surface of the Y-TZP ceramics when they were immersed in the simulated body fluid for 21 days. The cell response results indicated that the bioactive surface modification of Y-TZP ceramics could promote cell adhesion, propagation and osteogenic differentiation performance. Thus, our research results suggest that the highly bioactive Y-TZP ceramics could be a potential candidate for dental implant material.     

Validation of a Cleanroom Compliant Sonication-Based Decellularization Technique: A New Concept in Nerve Allograft Production

Defects of the peripheral nervous system are extremely frequent in trauma and surgeries and have high socioeconomic costs. If the direct suture of a lesion is not possible, i.e., nerve gap > 2 cm, it is necessary to use grafts. While the gold standard is the autograft, it has disadvantages related to its harvesting, with an inevitable functional deficit and further morbidity. An alternative to autografting is represented by the acellular nerve allograft (ANA), which avoids disadvantages of autograft harvesting and fresh allograft rejection. In this research, the authors intend to transfer to human nerves a novel technique, previously implemented in animal models, to decellularize nerves. The new method is based on soaking the nerve tissues in decellularizing solutions while associating ultrasounds and freeze–thaw cycles. It is performed without interrupting the sterility chain, so that the new graft may not require post-production γ-ray irradiation, which is suspected to affect the structural and functional quality of tissues. The new method is rapid, safe, and inexpensive if compared with available commercial ANAs. Histology and immunohistochemistry have been adopted to evaluate the new decellularized nerves. The study shows that the new method can be applied to human nerve samples, obtaining similar, and, sometimes better, results compared with the chosen control method, the Hudson technique.     

Size controlled synthesis of well-distributed nano-silver on hydroxyapatite using alkanolamine compounds

A well-distributed nano-silver hydroxyapatite composite has been successfully prepared by a one-pot synthesis method. Hydroxyapatite was separately synthesized by a sol-gel method, then impregnated with silver nanoparticles with the mediation of Uncaria gambir Roxb. leaf extract in the presence of three kinds of alkanolamine compound; monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) as capping agents. The effect of different capping agents on the properties of the silver nanoparticles and the nano-silver hydroxyapatite composite were studied. UV–visible spectrophotometer analysis exhibited absorbance peaks at 402–439 nm which specifically corresponds to spherical silver nanoparticles. Higher optical absorbance was observed in TEA-capped silver nanoparticles, than in DEA and MEA-capped ones. X-ray diffraction (XRD) analysis showed a highly crystalline hexagonal structure for hydroxyapatite and no detected metallic silver. However, the presence of 1.65% silver was confirmed by energy dispersive x-ray (EDX) spectroscopy analysis. Transmission electron microscopy (TEM) analysis revealed spherical silver nanoparticles with a size range of 2–62 nm (smallest mean diameter of 2 nm) adhered to the hydroxyapatite surface. The TEA capped impregnated silver nanoparticles were the smallest, corresponding to the best capping performance, followed by those capped by DEA and MEA. Small-sized nanoparticles on hydroxyapatite are beneficial for highly antibacterial bone implants.     

医用生物蛋白胶在胸外科手术中的应用

目的:观察医用生物蛋白胶对胸外科手术术后引流量的影响.方法:对同期胸外科手术实验组55人及观察组53人进行术后24h引流量及引流总量进行观察比较.结果:使用医用生物蛋白胶的实验组术后24h引流量及引流总量明显少于观察组(P＜0.05).结论:医用生物蛋白胶可有效减少胸外科手术的术后24h引流量及引流总量,促进术后恢复.     

悄然兴起的新型手术刀——激光刀

随着激光技术的发展,激光在临床医学领域的应用也日益增多.本文概述了激光手术刀的特点及应用领域,阐明了工程技术对医学的发展起着日益广泛而更加深刻的推动作用.     

年轻女性经乳晕单孔腔镜甲状腺手术18例

目的 探讨年轻女性经乳晕单孔腔镜甲状腺手术的价值.方法 2010年1月至2012年12月对18例≤35岁女性甲状腺结节患者行经乳晕单孔腔镜甲状腺手术.观察记录手术时间、术中出血量、术中皮下建腔面积、术后复发情况和美容效果.结果 18例手术均成功,无一例中转三孔腔镜手术或开放手术.手术时间106～205 min,平均157 min;术中出血量15～40 mL,平均25 mL;术中皮下建腔面积120～150 cm2,平均130 cm2.术后病理：甲状腺腺瘤13例,结节性甲状腺肿5例.术后随访4～23个月无复发.患者术后美容满意度评分8～10分,平均9.2分.结论 经乳晕单孔腔镜甲状腺手术具有安全、切口隐蔽、皮下建腔面积小、美容效果好的特点,尤其适合对美容有强烈要求的年轻女性患者.     

免装置手助腹腔镜脾切除门奇静脉断流术（附29例报告）

目的探讨免装置手助腹腔镜脾切除门奇静脉断流术的手术技术和可行性。方法采用免装置手助腹腔镜行脾切除门奇断流术29例。结果1例中转开腹手术,28例手术成功。手术时间70～300min,平均135min。术中出血50～1500mL,平均270mL。切除脾重500-1300g,平均810g。术后住院时间5～16d,平均9．2d。手助切口愈合良好,3例出现并发症,无手术死亡。结论免装置手助腹腔镜行脾切除门奇断流术不但安全可行,而且具有微创手术的优点,疗效满意。     

心理护理临床路径对显微血管减压术后功能延迟恢复患者的影响

目的探讨心理护理临床路径对显微血管减压术后神经功能延迟恢复患者的影响。方法将40例行显微血管减压术术后发生延迟恢复的患者按随机数字表法分为2组：观察组和对照组,每组20例。2组患者均采用常规治疗及常规护理。在此基础上,观察组实施心理护理临床路径。不同入院时间（入院时、入院后3 d、入院后1周）观察组实施心理护理临床路径采用90项症状自评量表（SCL-90）进行评分,采用SCL-90对观察组、对照组入院后1周进行评分,采用Zung抑郁自评量表（SDS）、焦虑自评量表（SAS）对观察组、对照组入院时、入院后1周进行评分。结果入院后1周观察组实施心理护理临床路径SCL-90评分值显著低于入院时及入院后3 d（P〈0.01）。观察组入院后1周躯体化、强迫症状、人际关系敏感、抑郁、焦虑、偏执SCL-90评分值均明显低于对照组（P〈0.05或P〈0.01）,观察组入院后1周敌对、恐怖SCL-90评分值与对照组比较差异均无统计学意义（均P〉0.05）。观察组入院后1周SDS、SAS评分值均明显低于对照组（均P〈0.01）,观察组入院后1周SDS、SAS评分值均明显低于入院时（均P〈0.01）。结论心理护理临床路径能有效地降低显微血管减压术后功能延迟恢复患者的焦虑、抑郁程度,改善了人际关系,促进患者神经功能的恢复。     

用插销法研究CO2气保焊条件下SA106C铸件的冷裂纹敏感性

用插销试验法研究了CO2气保焊条件下SA106C铸件的冷裂纹敏感性及断口特征。结果表明，在不预热和16kJ／cm热输入条件下，SA106C铸件的抗冷裂性好，临界断裂应力σer为560MPa，接近其抗拉强度σb，可在不预热条件下焊接该钢。当拘束拉伸应力高于σb。时，将发生失效断裂，断裂性质为典型的氯致延迟裂纹引起的断裂，断裂方式为棱角分明的沿晶(IG) 准解理穿晶(QC)。晶内出现较多短小、锋利、笔直的二次裂纹；启裂区的IG比例较大，随着裂纹的缓慢扩展．扩散氢含量逐渐降低．断口中IG减少，QCHE和二次裂纹都明显增加，而且QCHE中撕裂棱的塑性变形增大。CO2气保焊条件下，SA106C铸件的抗冷裂纹性好，主要与该方法能得到超低氢的焊接条件有关，此外还与该钢的碳当量(CEHW=0．48)不高，HAZ淬硬不明显有关，过热区组织主要为贝氏体，硬度为321HV．低于350HV的临界硬度。