钛合金种植体表面制备的生物活性膜*★

背景：传统的仿生方法通常采用常规模拟体液和1.5倍模拟体液，其缺点就在于涂层生长过于缓慢，生长周期长达数周甚至几个月。 目的：探讨3倍模拟体液诱导Ti-6Al-4V合金表面快速形成类羟基磷灰石涂层的能力。 设计、时间及地点：体外生物学分析。实验于2008-11/2009-03在中国科学院金属研究所完成。 材料：Ti-6Al-4V合金片由陕西省宝鸡市博达金属材料有限公司提供。 方法：将经过预处理的Ti-6A1-4V合金浸泡在37 ℃的3倍模拟体液中，为保持浸泡液成分的恒定，溶液每24 h更换1次，共浸泡3 d。 主要观察指标：用扫描电镜、X射线衍射仪和红外光谱仪分析涂层的形貌、相及元素组成。 结果：扫描电镜观察样品浸泡1 d时，表面被沉积膜覆盖，局部区域有较大颗粒状的晶体出现。浸泡3 d时，表面完全被沉积膜覆盖，且有大量颗粒状或鳞片状晶体出现，晶体沉积以某一区域为核心，持续生长。生成物主要由Ca，P，O，C等元素组成，但是没有检测到Al，V等元素的存在。X射线衍射仪和红外光谱仪分析浸泡3 d时Ti-6A1-4V合金表面制备的生物活性膜主要成分为羟基磷灰石。 结论：使用3倍模拟体液可以快速诱导Ti-6Al-4V合金表面类羟基磷灰石的沉积，显著缩短涂层形成的时间。 关键词：Ti-6Al-4V合金；高浓度模拟体液；仿生法；类羟基磷灰石     

医用镍钛形状记忆合金羟基磷灰石涂层的制备及其生物活性

背景：目前多采用等离子喷涂技术在钛及其合金表面涂覆羟基磷灰石涂层,制备成复合材料。但由于羟基磷灰石与钛合金基体的热膨胀系数相差较大,涂层在冷却过程中易产生脱落。 目的：在医用镍钛形状记忆合金表面制备致密、均匀的羟基磷灰石生物陶瓷涂层,利用动物实验考查镍钛/羟基磷灰石涂层材料的生物相容性。 方法：利用阴极旋转法在低温条件下从含钙、磷离子的电解水溶液中在镍钛形状记忆合金表面沉积了磷酸钙涂层,经碱处理获得羟基磷灰石涂层。分析工艺参数对涂层结构的影响。利用动物植入实验对该复合材料的生物活性进行研究,并与镍钛/羟基磷灰石与Ca3(PO3)2•2H2O混合涂层复合材料、医用镍钛形状记忆合金、医用钛合金进行对比。 结果与结论：电化学沉积-碱处理方法适合在镍钛形状记忆合金表面制备羟基磷灰石生物活性陶瓷涂层,沉积电压、温度对涂层结构有强烈影响。4种不同材料植入动物体内后周围均出现不同程度的组织增生,在骨膜组织切片中都可见软骨细胞且有骨小梁形成,涂覆有羟基磷灰石涂层的植入材料组织反应较轻,相应的组织切片中所显示出的软骨细胞、骨小梁数量最多,分布均匀,表明羟基磷灰石涂层提高了医用镍钛形状记忆合金的生物活性。     

一种碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法***☆◆

摘要 背景：目前在碳/碳表面制备羟基磷灰石涂层的方法有很多种，但所制涂层与基体的结合强度不高。 目的：提出一种在碳/碳复合材料表面制备高结合强度羟基磷灰石涂层的新方法。 方法：首先利用感应加热法在基体表面制备出无水磷酸氢钙涂层，而后对其进行水热处理，转变为羟基磷灰石相。扫描电镜观察涂层的形貌，划痕法测试涂层的临界载荷，顶出法测试剪切强度。 结果与结论：感应热沉积法可以在碳/碳复合材料表面制备出致密的块状晶粒结构的无水磷酸氢钙涂层；通过水热处理可以将其转变成结晶完好致密的羟基磷灰石涂层。涂层的临界载荷为13.31 N，剪切强度约为47 MPa。 关键词: 碳/碳复合材料；羟基磷灰石；高频感应加热沉积；水热反应；涂层 doi:10.3969/j.issn.1673-8225.2011.03.015     

纯钛表面微弧氧化膜的粗糙度与接触角**◆

目的：分析纯钛表面微弧氧化改性对表面氧化膜特性的影响。 方法：通过微弧氧化技术在含一定钙磷比例的电解液中制备纯钛表面氧化膜层,进而检测纯钛表面微弧氧化膜的粗糙度和接触角。 结果：微弧氧化处理后,纯钛表面生成微孔结构的氧化膜,直径1~5 µm。氧化膜层中含Ti、O、Ca、P 4种元素,由锐钛矿型、金红石型二氧化钛,结晶相羟基磷灰石组成;微弧氧化试样的表面粗糙度明显高于未处理纯钛试样(P < 0.05),表面接触角小于未处理纯钛试样(P < 0.05)。 结论：经微弧氧化技术处理后,纯钛表面生成了多孔的二氧化钛膜,含羟基磷灰石。膜层表面粗糙度增大,接触角减小,有利于细胞的附着和骨组织的整合。 关键词：钛;微弧氧化;粗糙度;接触角     

羟基磷灰石表面修饰人工角膜钛支架的生物相容性：电镜观察

背景：人工角膜是双眼角膜盲患者复明的希望,提高人工角膜材料的生物相容性使人工角膜与宿主角膜达到生物愈合是目前人工角膜的研究方向。 目的：扫描电子显微镜观察经羟基磷灰石表面修饰能否增加人工角膜纯钛支架的生物相容性。 方法：采用酸碱两步预处理法在人工角膜钛支架表面快速沉积羟基磷灰石涂层。将第4~6代兔角膜基质成纤维细胞直接接种于羟基磷灰石修饰的钛支架、纯钛支架及玻璃表面,3,24,48,72 h后,扫描电子显微镜观察材料表面的细胞黏附,伸展及增殖情况;将18只正常新西兰白兔随机分为2组,于右眼角膜基质层内分别植入羟基磷灰石修饰的钛支架、纯钛支架,术后6,12周取出人工角膜支架,扫描电子显微镜观察材料表面角膜组织贴附生长状态。 结果与结论：体外实验显示,细胞接种3 h和24 h后,细胞扩展面积及细胞张力丝长度：羟基磷灰石修饰的钛支架>玻璃>纯钛表面,羟基磷灰石修饰的钛支架表面的活细胞数多于其他材料表面(P < 0.05)。72 h后,羟基磷灰石修饰的钛支架表面完全被胶原覆盖。体内实验显示,扫描电子显微镜观察羟基磷灰石修饰的钛支架表面细胞外基质生长良好,与羟基磷灰石贴附紧密。而纯钛支架仅为角膜组织简单包裹。说明人工角膜纯钛支架经羟基磷灰石表面修饰后,其生物相容性增加。 关键词：人工角膜;羟基磷灰石;钛;表面改性;生物相容性;扫描电子显微镜 doi:10.3969/j.issn.1673-8225.2010.29.007     

琼脂-羟基磷灰石复合物的仿生合成及细胞相容性

背景：以有机大分子作为矿化模版进行骨组织修复材料的仿生构建，是目前骨修复材料的研究热点。而将琼脂应用于骨修复材料的报道较少。 目的：仿生合成一种由琼脂和羟基磷灰石组成的新型纳米复合骨组织修复材料，评价其理化性能和细胞相容性。 方法：①将一定量的非纳米羟基磷灰石的盐酸溶液，加入一定量的琼脂溶胶中，调整反应体系的pH值至7~8，然后将反应形成的复合物冷冻干燥后即得琼脂-羟基磷灰石复合材料。②将第3代SD大鼠骨髓基质细胞与琼脂-羟基磷灰石复合材料共培养，于培养1，3，5 d时观察细胞生长情况。 结果与结论：X射线衍射仪，傅里叶变换红外光谱仪，热分析仪，透射电镜和扫描电镜对材料进行表征分析，显示琼脂良好控制了磷灰石晶体的生长，纳米的磷灰石晶体均匀分布在琼脂纤维中，琼脂-羟基磷灰石复合物具有多孔结构。共培养3，5 d时骨髓基质细胞在复合物中生长良好，并有较明显的细胞骨架形成。提示琼脂-羟基磷灰石复合物具有良好的理化性质和细胞相容性。 关键词：琼脂；羟基磷灰石；仿生合成；细胞相容性；骨修复材料 doi:10.3969/j.issn.1673-8225.2010.03.008     

羟基磷灰石/聚乙烯醇水凝胶的制备与生物活性评价

背景：先前的研究表明,羟基磷灰石/聚乙烯醇水凝胶复合水凝胶(hydroxyapatite/ polyvinyl alcohol hydrogel,HA/PVA-H)具有较好的机械性能和耐摩擦磨损性能,这说明HA/PVA-H复合材料具有早期承载能力和较好的生物活性。那么HA/PVA-H复合材料能否通过羟基磷灰石粒子与周围骨组织较快地形成活性结合呢？ 目的：制备羟基磷灰石/聚乙烯醇水凝胶,并对其进行生物学评价。 方法：将Ca(OH)2研磨过筛后,配制成一定浓度的悬浮分散液;加入质量分数15%的PVA水溶液中,添加二甲亚砜,最后按Ca/P比1.67: 1加入H3PO4的乙醇溶液,制备HA/PVA-H。对试样进行体外模拟体液培养实验,测试浸泡前后SBF浸泡液的变化,并利用扫描电镜、FTIR、XRD 对材料的结构进行了表征和分析。 结果与结论：扫描电镜观察可知羟基磷灰石/聚乙烯醇水凝胶表面有结晶体形成,经XRD分析确认为弱结晶的羟基磷灰石晶体;浸泡之后浸泡液的pH值与Ca、P离子浓度下降,同时FTIR结果显示试样中的PO43-特征峰得到增强,且有CO32-的特征峰形成。结果提示,羟基磷灰石/聚乙烯醇水凝胶复合材料具有较好的生物活性。     

两种新型羟基磷灰石生物复合材料的制备

背景：为了进一步拓展羟基磷灰石应用范围,提高其实用性,课题组制备了两种具有不同功能的超细羟基磷灰石生物复合材料：载银羟基磷灰石和壳聚糖表面改性羟基磷灰石。 目的：观察两种新型羟基磷灰石生物复合材料的抑菌性和稳定性。 方法：以氢氧化钙和磷酸二氢钙为前驱,用均相化学沉淀法合成制备了羟基磷灰石。以此为基础研究制备载银羟基磷灰石和壳聚糖表面改性羟基磷灰石,采用抑菌圈法定性检验载银羟基磷灰石的抑菌性,通过测定Zeta电位及平均粒度检验壳聚糖表面改性羟基磷灰石的稳定性。 结果与结论：载银率为1.2%的羟基磷灰石对大肠杆菌和金黄色葡萄球菌均有较强的抑菌作用,其抑菌圈直径分别为10 mm,11 mm;羟基磷灰石微粒的表面电荷受pH值及壳聚糖加入量等因素的影响,pH值向大于6.8或小于6.8变化,壳聚糖加入量在一定范围内(≤0.12%),均能使Zeta电位绝对值越大,稳定性增强。用壳聚糖对普通的羟基磷灰石粒子进行改性,可得到荷正电且稳定存在的羟基磷灰石水悬浮液。     

纳米羟基磷灰石/聚酰胺66颈前路减压后前方骨缺损仿生髂骨的制备及性能

背景：在椎体和椎间盘切除以后,对于减压后前方骨缺损的修补长期以来以钛网和自身髂骨两种方式为主,但效果都不尽理想。 目的：制备纳米羟基磷灰石/聚酰胺66复合材料,对其进行表征和生物力学性能检测。 设计、时间及地点：重复性对比实验,于2008-01/12在南京航空航天大学材料科学与技术学院无机材料实验室完成。 材料：利用水热反应法制备纳米羟基磷灰石晶体,通过液相混合、冷压烧结制备出纳米羟基磷灰石/聚酰胺66仿生骨块。 方法：切除新鲜冰冻正常颈椎标本C5椎体,植入不同材料,钢板螺钉内固定,进行生物力学测试。具体分组为：正常颈椎组、纳米羟基磷灰石/聚酰胺66仿生髂骨钢板螺钉内固定组、髂骨植骨钢板螺钉内固定组。加载时模拟人体颈椎生理运动,即中心位、前屈位、后伸位和侧屈位4种生理情况。 主要观察指标：①通过X射线衍射仪对材料的物相进行表征。②红外图谱对材料的基团构成进行表征。③扫描电镜观察仿生骨的端口形貌。④正常颈椎、仿生髂骨、髂骨植骨进行生物力学检测。 结果：①X射线衍射结果表明纳米羟基磷灰石和聚酰胺66的主要衍射峰在复合材料中存在,但纳米羟基磷灰石对聚酰胺66的β晶型衍射峰起到宽化、削弱的作用。②红外图谱表明两者之间存在氢键。③扫描电镜观察,两者结合密实,界面性能优异。④通过生物力学实验,对比得出,仿生髂骨在载荷-应变变化、载荷-位移变化、应力强度方面都优于髂骨植骨,仅次于正常颈椎骨。 结论：所制备的纳米羟基磷灰石/聚酰胺66仿生骨力学性能优异,是一种理想的颈椎替代材料。 关键词：纳米羟基磷灰石/聚酰胺66;生物复合材料;生物力学性能;髂骨植骨;颈前路手术     

纯钛表面梯度生物活性涂层材料生物相容性研究

目的评价复合氧化及水热沉淀法制备纯钛表面梯度生物活性涂层材料生物相容性和骨诱导能力。方法通过对L929成纤维细胞和M373成骨细胞体外细胞培养进行细胞相容性实验和动物颅骨植入实验评价梯度羟基磷灰石(HA)涂层生物相容性和骨诱导能力。结果涂层表面L929成纤维细胞附着与增殖实验提示多孔的羟基磷灰石表面涂层对细胞的黏附生长有诱导作用,促进细胞在其表面繁殖。体外细胞毒性实验提示各组材料对M373成骨细胞的生长、增值、代谢无不良影响。在细胞接种后期HA试件组的细胞增殖数较其他组有显著增加。颅骨植入实验提示羟基磷灰石涂层组在诱导成骨反应方面优于其它组。结论复合氧化及水热沉淀法制备纯钛表面梯度生物活性涂层材料具有良好的生物相容性和骨诱导能力,值得作为新型颅骨修补材料。     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

帕金森病运动症状进展分析

目的分析帕金森病(PD)患者运动症状进展特点。方法采用PD统一评分量表(UPDRS)Ⅲ对912例PD患者进行评估。结果与病程1年的患者比较,除病程1~2年的患者外,其他病程患者的UPDRSⅢ评分、强直分、姿势或步态异常分、轴性症状总分、言语分、步态分显著升高(均P0.05),病程5~6年及14年患者的震颤分,病程5~6年、7~8年、9~13年、14年患者的运动迟缓分、姿势分显著升高(P0.05~0.01)。轴性症状进展速度高于UPDRSⅢ评分。结论 PD患者病程早期UPDRSⅢ评分进展快,震颤症状进展独立于其他症状,轴性症状评分较UPDRSⅢ更敏感地反映疾病加重趋势。     

Frequency of accumulation of filaments in adaxonal cytoplasm of Schwann cells of myelinated fibers of rat spinal roots

Summary The frequency of accumulation of 6-nm filaments in the adaxonal cytoplasm of Schwann cells in the 6th lumbar dorsal and ventral roots was evaluated in 4-, 8-, 26- and 45-week-old Sprague-Dawley rats. The frequency was higher in 4- and 8-week-old (growing) rats than in 26- and 45-week old (mature) rats, and also higher in ventral than in dorsal roots in 4-, 8- and 26-week old rats. There were no clusters on certain groups of myelinated fibers according to the size of transverse axonal area, in both the ventral and dorsal roots. Therefore, this accumulation may reflect certain functions of the adaxonal cytoplasm of Schwann cell during natural growth and maturation of the axon and myelin sheath.     

Function of circle of Willis

Nearly 400 years ago, Thomas Willis described the arterial ring at the base of the brain (the circle of Willis, CW) and recognized it as a compensatory system in the case of arterial occlusion. This theory is still accepted. We present several arguments that via negativa should discard the compensatory theory. (1) Current theory is anthropocentric; it ignores other species and their analog structures. (2) Arterial pathologies are diseases of old age, appearing after gene propagation. (3) According to the current theory, evolution has foresight. (4) Its commonness among animals indicates that it is probably a convergent evolutionary structure. (5) It was observed that communicating arteries are too small for effective blood flow, and (6) missing or hypoplastic in the majority of the population. We infer that CW, under physiologic conditions, serves as a passive pressure dissipating system; without considerable blood flow, pressure is transferred from the high to low pressure end, the latter being another arterial component of CW. Pressure gradient exists because pulse wave and blood flow arrive into the skull through different cerebral arteries asynchronously, due to arterial tree asymmetry. Therefore, CW and its communicating arteries protect cerebral artery and blood–brain barrier from hemodynamic stress.     

Effects of prevention of afferentation of the development of the chick optic lobe

BONDY, S. C., M. E. HARRINGTON AND C. L. ANDERSON. Effects of prevention of afferentation on the developmentof the chick optic lobe. BRAIN RES. BULL. 3(5) 411–413, 1978.—The effects of unilateral extirpation of the right optic cup of the three-day incubated chick embryo upon the rate of synthesis and the stability of DNA in the non-innervated optic lobe, have been studied. This surgical procedure prevents innervation of the optic lobe contralateral to the removed eye, while the other optic lobe is normally innervated by retinal ganglion cells of the remaining eye. At the 20th day of incubation, the DNA content of the non-innervated lobe was below that of the paired lobe receiving normal innervation. This deficiency of cell number was caused by two events; death of an excess number of neurons formed early in embryogenesis and a reduced rate of glial proliferation in the later stages of incubation.     

Modelling of movement of the lamprey: Control of oscillators

This article discusses the control methods of the central pattern generator (CPG). First a control model of the CPG is presented using 2 oscillators, and we suggest that phasic modulation to the CPG by means of phasic information is effective for controlling the phase difference between oscillators. Next, two models for controlling the CPG of a lamprey are proposed. One model describes a control system from the brain stem, in which the reticulospinal neurons control the CPG by receiving feedback signals and sending control signals to the neck region of the CPG. The other is a model for learning an localized control system to generate a desired motor pattern. By means of these models, a role of the efference copy is suggested.     

利培酮对精神分裂症患者生活质量的影响

目的：比较利培酮与氟哌啶醇对精神分裂症患者生活质量的影响。方法：对门诊72例服用氟哌啶醇及74例服用利培酮的精神分裂症患者用生活质量综合评定问卷（GQOLI）、阳性与阴性症状量表（PANSS）、副反应量表（TESS）进行评定。结果：利培酮组患者治疗后生活质量有所提高,而氟哌啶醇组患者生活质量有所下降。结论：利培酮治疗有利于患者提高生活质量。     

腺垂体功能减退症临床特征变化分析

目的探讨腺垂体功能减退症患者的病因结构变化及临床表现。方法回顾性分析我院2013-01—2016-12住院及门诊78例腺垂体功能减退症患者的临床资料。结果男32例(41.03%),女46例(58.97%);诊断时年龄11~89岁,平均62.5岁;鞍区占位(包括术前及术后)52例(66.67%),席汉综合征8例(10.26%),空泡蝶鞍9例(11.65%),病因不明8例(10.26%),垂体-下丘脑发育不良1例(1.28%)。首次就诊科室:纳差厌食、恶心呕吐就诊于消化内科36例(46.15%)最常见。ACTH+TSH+Gn+G激素缺乏为19例最多,占24.36%,ACTH+TSH+Gn缺乏15例,占19.23%。结论腺垂体功能减退症病因结构发生变化,发病人群、首发症状及受累激素也不同,患者女性多于男性,发病年龄偏高,症状不典型,分布于临床多个科室,其中以低钠血症为首发临床表现就诊消化内科最多。     

Standards of instrumentation of EMG

Standardization of Electromyography (EMG) instrumentation is of particular importance to ensure high quality recordings. This consensus report on “Standards of Instrumentation of EMG” is an update and extension of the earlier IFCN Guidelines published in 1999. First, a panel of experts in different fields from different geographical distributions was invited to submit a section on their particular interest and expertise. Then, the merged document was circulated for comments and edits until a consensus emerged.The first sections in this document cover technical aspects such as instrumentation, EMG hardware and software including amplifiers and filters, digital signal analysis and instrumentation settings. Other sections cover the topics such as temporary storage, trigger and delay line, averaging, electrode types, stimulation techniques for optimal and standardised EMG examinations, and the artefacts electromyographers may face and safety rules they should follow. Finally, storage of data and databases, report generators and external communication are summarized.     

Effect of high simple dose of cisplatinum and of radiation on the brain of rabbit

Abstract

In former studies of intracarotid and intravenous administration of cisplatinum, separate and combined with brain irradiation, we found no cerebral damage. In this study! gradually increasing high doses (above the therapeutic ones) of cisplatinum were administered intravenously to one series of rabbits arid increasing high amounts of irradiation (above the therapeutic amounts) were given to another series. Although the rabbits that received highest doses of irradiation developed areas of alopecia and skin ulcers on the head! the general clinical and histopathologic examination of the rabbits brains in both series was normal. The purpose of this study was to establish the effects of high doses of intravenous cisplatinum and irradiation on the rabbits brains. [Neural Res 1997; 19: 216–218]