腰椎棘突间记忆合金动态稳定装置理论验证

为了在腰椎退变性疾病保守治疗和融合手术中间地带寻找一种有效的预防与辅助相结合的微创治疗方式,通过对比目前常用的几种腰椎棘突间动态稳定系统的临床疗效观察和优缺点,以及对腰椎棘突间的生理结构、生物力学和相关数据的分析,在充分了解记忆合金材质的基础上,自行设计研究一种记忆合金材料的新型腰椎棘突间动态固定装置,既能重建腰椎的正常生物力学特性,满足人体脊柱的正常活动,又避免对原有结构的破坏,减少术后并发症的发生,同时也可以优化目前的治疗方法。通过研究,腰椎棘突间记忆合金动态稳定装置在理论上效果满意,可以解决现有技术的不足,优于目前的几种腰椎棘突间动态稳定系统。     

Compressive Properties and Energy Absorption Characteristics of Extruded Mg-Al-Ca-Mn Alloy at Various High Strain Rates

This paper is focused on the mechanical properties and the energy absorption characteristics of the extruded Mg-Al-Ca-Mn alloy in different compression directions under high strain rate compression. Compressive characterization of the alloy was conducted from the high strain rate (HSR) test by using a Split Hopkinson Pressure Bar (SHPB). Results show that the investigated alloy exhibits a strong strain rate sensitivity. With the rise of strain rate, the compressive strength is increased significantly, and the deformation ability also improves. When compressed along the extrusion direction, as the strain rate increases, the total absorbed energy E, the crush force efficiency (CFE), and the specific energy absorption SEA of Mg-Al-Ca-Mn alloy are all greatly improved as compared with those obtained along other compression directions.     

Influence of Fine Grains on the Bending Fatigue Behavior of Two Implant Titanium Alloys

By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm²), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, such as hardness, residual stress, and roughness. The rotating–bending fatigue limits of TC4 and TLM subjected to ultrasonic impact are improved by 13.1% and 23.7%, separately. Because of the bending fatigue behavior, which is sensitive to the surface condition, cracks usually initiate from the surface defects under high stress amplitude. By means of an ultrasonic impact tip with the size of 8 mm, most of the inner cracks present at the zone with a depth range of 100~250 μm in the high life region. The inner crack core to TC4 usually appears as a deformed long and narrow α-phase, while the cracks in TLM specimens prefer to initiate at the triple grain boundary junctions. This zone crosses the grain refined layer and the deformed coarse grain layer. With the gradient change of elastic parameters, the model shows an increase of normal stress at this zone. Combined with the loss of plasticity and toughness, it is easy to understand these fatigue behaviors.     

可吸收棒或钛合金螺钉治疗MasonⅡ型桡骨头骨折的疗效

文题释义：可吸收棒、钛合金螺钉内固定：两者均属于MasonⅡ型桡骨头骨折螺钉内固定法，主要区别在于其制作材质不一样，前者是由聚乳酸制成的可吸收高分子聚合物，而后者为钛合金制成，需二次手术取出。桡骨头骨折Mason分类：Ⅰ型，为线状骨折，即无移位型骨折，骨折线可通过桡骨头边缘或呈劈裂状；Ⅱ型，为有移位的骨折，有分离的边缘骨折；Ⅲ型，为粉碎型骨折，移位或无移位或呈塌陷性骨折；Ⅳ型，为桡骨头骨折伴有肘关节脱位。 背景：目前切开复位内固定是治疗MasonⅡ型桡骨头骨折的有效方法，内固定的选择有螺钉、微型钢板、克氏针、可吸收棒或钉等，临床疗效报道不一致。 目的：对比可吸收棒或钛合金螺钉内固定治疗MasonⅡ型桡骨头骨折的临床疗效。方法：选择2016年1月至2017年2月四川省人民医院收治的桡骨头骨折患者25例，其中男16例，女9例，年龄38-61岁，均进行切开复位内固定治疗，其中13例的内固定材料为钛合金螺钉，另12例的内固定材料为可吸收棒。术后随访拍摄X射线片，确定骨折愈合时间。末次随访时，对比两组目测类比评分、肘关节活动度及肘关节功能Mayo评分与Broberg-Morrey 评分。该研究已通过四川省医学科学院·四川省人民医院伦理委员会的审批。结果与结论：①可吸收棒组、钛合金螺钉组的骨折愈合时间分别为(2.35±0.92)，(2.10±0.47)个月，组间比较差异无显著性意义(P > 0.05)；②末次随访时，两组间肘关节功能Mayo评分与Broberg-Morrey 评分比较差异均无显著性意义(P > 0.05)；③末次随访时，两组间肘关节屈曲、伸直、旋后、旋前角度比较差异均无显著性意义(P > 0.05)；④末次随访时，两组目测类比评分比较差异均无显著性意义(P > 0.05)；⑤结果表明，可吸收棒与钛合金螺钉治疗MasonⅡ型桡骨头骨折的临床疗效相似，但可吸收棒避免了二次手术取出内固定及应力性遮挡等情况。 ORCID: 0000-0003-4778-7050(杨晓) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程     

基于CAD/CAM技术的钛合金制品在正颌外科手术中应用研究进展

计算机辅助设计与计算机辅助制作（computer aided design and computer aided manufacturing，CAD/CAM）技术发展迅速，在医学领域尤其是外科领域已被广泛应用。正颌外科是外科学的重要组成部分，其对于治疗的精度与材料的质量要求严格，而基于CAD/CAM技术的钛合金制品（如钛制定位导板、钛制钻孔导板及钛制截骨导板等）具有良好的性能，在该领域会有很好的应用前景。文章就基于CAD/CAM技术的钛合金制品在正颌外科手术中应用研究进展做一综述。     

Effect of Pre-Stretch on the Precipitation Behavior and the Mechanical Properties of 2219 Al Alloy

The influence of pre-stretch on the mechanical properties of 2219 Al alloys sheets were systematically investigated, with the aim of examining the age-strengthening in parts draw-formed from as-quenched sheets. The precipitation was characterized based on differential scanning calorimetry (DSC) analysis and transmission electron microscope (TEM) observation of specimens of as-quenched and quenched-stretched condition to address the influence of pre-stretching. A tensile test was performed to evaluate the effect on mechanical properties. The introduction of pre-stretching endues increased yield strength (YS) and thus can be helpful to exert the potential of the alloy. Peak YS of 387.5 and 376.8 MPa are obtained when specimens pre-stretched for 10% are aged at 150 and 170 °C, respectively, much higher than that obtained in the non-stretched specimens (319.2 MPa). The precipitation of Guinier-Preston zone (G.P. zones) and the transition to θ″ shifts to a lower temperature when pre-stretched is performed. The high density of dislocations developed during the stretching contributes to the acceleration in precipitation. Quench-stretched specimens present a much quicker age-hardening response at the beginning stage, which endue higher peaked yield strength. The yield strength, however, decrease much more quickly due to the recovery that occurs during the aging processes. The study suggested the feasibility of aging draw-formed components of 2219 Al alloy to obtain high strength.     

2 种新型骨植入钛合金的细胞生物相容性研究

目的:研究国内2种新研制骨植入钛合金Ti1、Ti2对成骨细胞生物学行为的影响。方法:采用SD乳鼠体外原代分离培养的成骨细胞,将细胞分别接种于新型钛合金表面建立体外共同培养。采用MTT比色试验检测第3天成骨细胞的增殖百分率,采用扫描电镜(SEM)观察细胞形态学变化,并且对培养第5天时细胞碱性磷酸酶(ALP)功能活性进行检测。结果:成骨细胞在新合金表面增殖百分率、碱性磷酸酶活性检测值均高于对照组,细胞增殖百分率及碱性磷酸酶吸光度值与对照组间统计学分析无显著性差异(P>0.05)。扫描电镜观察细胞在新合金表面伸展状况良好、黏附牢固,并具有成骨细胞典型形态特征。结论:2种新型钛合金对成骨细胞学行为无不良影响。     

老年人三种不同材料全口义齿满意度调查

目的：了解老年人对不同材料全口义齿修复的满意程度。方法：选择43例全口牙列缺失的患者，制作塑胶、钴-铬合金、纯钛3种不同材料的全口义齿，进行满意度调查。结果：3种不同的义齿咀嚼功能、稳定固位功能、语言功能及外观满意度无显著差异，坚固性、舒适度，合金组明显优于塑胶组，舒适度纯钛组更优于钴-铬合金组。结论：铸造合金义齿值得推广。     

铸模温度对牙科用钛铌锆锡合金铸流率影响的研究

目的:通过对钛铌锆锡(Ti-Nb-Zr-Sn)合金铸流率的研究,为钛铌锆锡合金临床应用提供合理的铸造参数。方法:采用网状试样法,评价钛铌锆锡合金、纯钛、钛铝钒(Ti-6A l-4V)合金分别在3种铸模温度(室温、300℃、600℃)下的铸流率,做统计学分析。结果:在室温及300℃铸造时钛铌锆锡合金铸流率明显低于纯钛及钛铝钒合金;在600℃铸造时3种合金铸流率没有明显差别。该合金室温及300℃组铸流率明显低于600℃组。结论:为保证临床义齿铸造的完整性,钛铌锆锡合金铸造时铸模温度应在600℃以上。     

Influence of phase transformation on the torsional and bending properties of nickel-titanium rotary endodontic instruments

AIM: To investigate the relationship between the functional properties and the phase transformation of nickel-titanium endodontic instruments. METHODOLOGY: Five types of rotary nickel-titanium endodontic instruments with a 0.30 mm diameter tip (EndoWave, HERO 642, K3, ProFile.06, and ProTaper) were selected to investigate torsional and bending properties, and phase transformation behaviour. A torsional test was performed according to ISO publication 3630-1, and maximum torque and angular deflection at fracture were measured. Bending load of the instruments was measured in a cantilever-bending test at 37 degrees C with the maximum deflection of 4.0 mm. A stainless steel K-file was used for reference. Phase transformation behaviour was measured by differential scanning calorimetry (DSC). From the DSC curve, transformation temperatures were calculated. Data were analysed by anova and the Tukey-Kramer's test. RESULTS: The maximum torsional torque values of HERO, K3 and ProTaper were significantly higher (P < 0.05) than those of EndoWave, ProFile and K-file. The K-files had the lowest torque value. Angular deflection at fracture was significantly higher (P < 0.05) for K-files than that for any nickel-titanium instrument. The bending load values of HERO and K3 were significantly higher (P < 0.05) than those of EndoWave, ProFile, ProTaper and K-file. The K-files had the lowest load value, although residual deflection remained. The transformation temperatures of HERO and K3 were significantly lower (P < 0.05) than those of EndoWave, ProFile and ProTaper. CONCLUSIONS: The functional properties of nickel-titanium endodontic instruments, especially their flexible bending load level, were closely related to the transformation behaviour of the alloys.