高血压心肌肥厚状态下心肌细胞微尺度刚度变化的实验研究

目的:探讨高血压心肌肥厚时心肌细胞刚度变化及与心律失常的可能联系。方法:急性分离不同周龄(12周龄/21周龄)自发性高血压大鼠(spontaneously hypertensive rat,SHR)与正常同源常压大鼠(wistar-Kyoto,WKY)的心室肌细胞,利用原子力显微镜采集细胞微区力曲线,获取杨氏模量信息,进行统计分析。结果:12周龄及21周龄的SHR心室肌细胞杨氏模量均明显高于同龄正常对照组(4.61 kPa±2.08 kPa vs.3.55 kPa±1.35 kPa,5.95 kPa±1.98kPa vs.3.79 kPa±1.66kPa,P0.01)。21周龄与12周龄SHR心室肌细胞杨氏模量比较,前者显著升高(5.95 kPa±1.98 kPa vs.4.61 kPa±2.08 kPa,P0.01),而21周龄与12周龄WKY心室肌细胞杨氏模量比较则无明显变化(3.79 kPa±1.66 kPa vs.3.55 kPa±1.35 kPa,P0.05)。结论:高血压发生心肌肥厚时心室肌细胞力学性质发生改变,即杨氏模量变大,细胞刚度增加,并且随着心肌肥厚严重程度逐渐加剧,可能参与心律失常的发生和维持。     

子宫内膜异位症在位子宫内膜的超微结构

目的对正常和子宫内膜异位症 (ｅｎｄｏｍｅｔｒｉｏｓｉｓ ,ＥＭ)在位子宫内膜腺上皮的超微结构进行对比性研究 ,以求找出有关ＥＭ在位内膜本身所具有的特点及其在发病过程中所起的作用 ,以探讨ＥＭ的发病机制及引起不孕的可能原因。方法 :对ＥＭ在位增生早期子宫内膜 6例以及正常育龄妇女增生早期子宫内膜 3例 ,按常规透射电镜标本制作方法处理 ,进行超微结构对比性研究。结果(1)正常增生早期子宫内膜腺上皮的超微结构 :腺上皮细胞呈柱状 ,形态规则、一致 ,细胞排列整齐 ,细胞基底面位于基底膜上 ,细胞顶部围成腺腔。分泌细胞顶部呈圆顶状…     

子宫内膜癌的超微结构研究

对２１例子宫内膜癌进行超微结构观察。其中子宫内膜腺癌１６例,子宫内膜乳头状癌２例,透明细胞癌２例,鳞腺癌１例。子宫内膜腺癌以形成腺腔及微绒毛为特征,随着肿瘤分化程度的降低,癌细胞异型性增加,并出现篮网状核仁。子宫内膜乳头状癌见分支管道状腔及纤毛细胞。透明细胞癌的形态学特点是细胞浆内多量糖原降集。研究显示,子宫内膜癌的主要形态学特征是腺腔形成,同时因保留了其来源于苗勒氏管上皮多方向分化的潜能而分化出纤毛细胞、粘液细胞及鳞状上皮细胞,进而形成不同组织学类型的子宫内膜癌。     

原子力显微镜在细胞力学特性研究中的进展

原子力显微镜(AFM)能够以高分辨率和高灵敏度实现液体环境下活细胞的操作和检测,利用AFM力曲线测量功能还可以获得细胞力学特性的相关信息。在简要介绍AFM力曲线测量原理的基础上,从细胞的杨氏模量、硬度和配体-受体之间相互作用力三个方面,详细阐述了近年来AFM在细胞力学特性研究中的发展状况,并着重介绍了其在细胞杨氏模量研究中的进展,表明AFM已经成为细胞力学特性研究中重要的生物显微技术。最后,针对AFM的不足及局限性,提出了目前存在的问题,并对AFM在细胞力学特性研究中的前景进行了展望。     

宫颈上皮脱落细胞的微尺度力学性质及形貌学研究

目前临床中对宫颈脱落细胞的检查多局限于大体细胞形态学的观察.本文应用原子力显微镜及环境扫描电子显微镜对5例临床宫颈炎患者的宫颈脱落细胞进行了微区力学性质表征以及细胞表面微观形态的成像.结果显示,患者正常形态宫颈上皮脱落细胞在针尖压入深度为700 nm时杨氏模量近似正态分布,峰值在20～30kPa.且细胞表面微嵴明显,微...     

基于原子力显微镜的压痕模式和双模纳米力学模式在模量表征中的影响因素

原子力显微镜是表征材料微观力学性质的重要手段,本文基于原子力显微镜的压痕法和双模纳米力学法,探究薄膜/基底材料与多层二维材料杨氏模量测定过程中的影响因素,分析了基底硬度、二维材料厚度以及环境湿度对两种纳米力学表征结果的影响,为研究适用于纳米材料微观力学的测定提供参考.     

E-cad在子宫内膜癌中的表达及意义

目的 :探究E-cad在子宫内膜癌中的表达及意义。方法:选取笔者所在医院2014年8月-2015年8月收治的子宫内膜癌患者40例展开研究,将这40例患者作为观察组,同时选取30例正常增生期子宫内膜患者、30例单纯型增生子宫内膜患者因30例复杂型或伴不典型增生子宫内膜患者作为对照组,对比两组患者E-cad的表达情况。结果:在正常增生期子宫内膜中,E-cad所占有的阳性率达到了93.3%,与子宫内膜癌相比表达要强,两者比较具有明显的统计学差异(P0.05),而Ecad在复杂型或伴不典型增生子宫内膜中,E-cad所表现出的阳性率为53.3%,明显低于E-cad在正常增生期子宫内膜中的表达阳性率,两者比较具有明显的统计学差异(P0.05)。而肌肤浸润深度小于1/2的患者要比肌肤浸润深度不小于1/2的患者E-cad表达阳性率明显要高,两者比较具有统计学差异(P0.05)而淋巴转移者表达则要明显低于五淋巴转移者(P0.05)。结论:在子宫内膜癌中,E-cad的表达与肌肤浸润深度以及淋巴转移等有着明显的相关性,三者之前呈现的是负相关的关系。E-cad能够对子宫内膜癌产生一定的影响,应用E-cad来进行子宫内膜癌的检测,可以有效的提高诊断结果的精确性,从而使得子宫内膜癌的患者生存几率大大提升。     

子宫内膜异位症相关性疼痛与血管形成的关系

目的：检测卵巢子宫内膜异位症（ovarian endometriosis,OEMs）周围血管形成,探讨子宫内膜异位症（endometriosis,EMs）相关性疼痛与血管形成的关系。方法：视觉模拟评分法（Visual analogue scale,VAS）按疼痛程度将患者分为A、B两组,A组病例无症状或者有轻微痛经,B组病例表现为中等及严重痛经或者有与经期相关的盆腔疼痛、坠胀。以多普勒超声和免疫组化法,分别检测两组囊肿周围血流分布及血流阻力指数（resistent index,RI）、搏动指数（pulsatility index,PI）和微血管密度（microvessel density,MVD）,并对检测结果进行统计学分析。结果：两组囊肿周围血流分布、PI、RI、MVD均有显著性差异（P〈0.05）。结论：子宫内膜异位症相关性疼痛与血管形成有关。     

人羊膜上皮细胞和间质细胞的分离培养

目的:探讨人羊膜上皮细胞和羊膜间质细胞的分离、培养及鉴定。方法:取足月妊娠剖宫产术中的羊膜组织剪成碎片,胰蛋白酶消化15min,共四次,取消化液1000rpm离心5min收集细胞。剩余羊膜组织加入1.0g/L的胶原酶和0.1g/L的DNA酶,39℃消化120min,消化液1000rpm离心5min收集细胞。用含10%胎牛血清的DMEM/F12培养液培养、传代。倒置显微镜下观察其细胞形态及细胞生长情况。通过免疫细胞化学的方法对细胞进行细胞鉴定。结果:通过不同的酶消化分离法可以将羊膜上皮细胞和间质细胞进行细胞分离培养,羊膜细胞体外一段时间内表现出良好的细胞增殖能力和传代能力。胰蛋白酶消化的细胞角蛋白染色呈阳性,波形蛋白染色呈阴性。胶原酶消化的细胞波形蛋白色阳性,角蛋白染色阴性。结论:羊膜上皮细胞和间质细胞能够在体外分离、扩增。这为羊膜细胞进行细胞治疗和组织工程技术奠定了实验基础。     

Nd:YAG激光治疗轻度子宫内膜异位症疗效观察

子宫内膜异位症 (ＥｎｄｏｍｅｔｒｉｏｓｉｓＥｍ)是妇科常见疾病 ,主要表现为进行性痛经、不孕和盆腔包块。目前尚无十分有效的治疗措施。近 10年来 ,本科应用Ｎｄ:ＹＡＧ激光治疗轻度Ｅｍ ,取得良好疗效 ,现将结果报导如下 :1　资料和方法1984年 7月至 1999年 6月因痛经、不孕等就诊于本院的患者 ,在局麻下行腹腔镜检查、子宫直肠窝、膀胱反折腹膜、宫骶韧带或盆腔腹膜有分散的泡状、息肉状或片状红色、暗红色或褐色的异位内膜病灶即诊断为轻度Ｅｍ ,共 470例 ,年龄 19～ 43岁 ,平均 2 6 3岁。腹腔镜明确诊断后 ,用利多卡因和庆大霉素溶…     

Mapping of elastic modulus at sub-micrometer scale with acoustic contact resonance AFM

Atomic Force Acoustic Microscopy (AFAM) is a powerful near field technique combining the high spatial resolution of Atomic Force Microscope (AFM) with ultrasonic stresses to access mechanical properties of material shallow surfaces (essentially local stiffness magnitudes like Young modulus). In this article, we discuss different experimental set-up and modelling approaches to determine quantitatively the Young modulus of thin films. Static experiments carried-out on dense and nanoporous silica have shown a good agreement with nanoindentation experiments. Stiffness mapping have also been performed on macroporous silica and copper interconnect structures, showing the ability of our set-up to sense different mechanical answers at sub-micrometer scale.     

纳米压痕法分析无铅焊点内界面金属化合物的力学性能

根据实际工艺流程和服役工况制备了微电子封装中3种无铅焊点(Sn3.0Ag0.5Cu、Sn0.7Cu和Sn3.5Ag)内界面金属化合物(IMC)的试样;利用扫描电镜(SEM)和能量色散X射线荧光光谱仪(EDX)对所制IMC的形貌和化学成分进行了分析;另外,借助纳米压痕仪,采用连续刚度测量(CSM)技术在不同的加载速率下对所制IMC的弹性模量和硬度进行了测量。结果表明,3种无铅焊点内的IMC均为Cu6Sn5,其弹性模量分别为98.93±3.37,113.55±4.58和(102.16±3.11)GPa,硬度分别为5.18±0.14,5.78±0.11和(5.55±0.19)GPa。     

Quantitative analyses of topography and elasticity of living and fixed astrocytes

The topography and elasticity of living and fixed astrocytes cultured from the rat cerebra were studied quantitatively by atomic force microscopy (AFM). Ridge-like structures reflecting F-actin beneath the cell membrane were prominent in the contact-mode images of living astrocytes. Many of these ridges became unclear after fixation (2% glutaraldehyde). In addition, the ridge-like structures were invisible in the topography of living cells observed at zero-loading force in the force mapping mode, which is considered to show the real cell surface not pressed down by an AFM tip. The topography of fixed cells observed both in the contact mode and at zero-loading force in the force mapping mode was similar to that of living cells observed at zero-loading force in the force mapping mode, although some deformed areas were detected in the fixed cells. The elasticity map images of living astrocytes showed that the cell membrane above the nucleus was softer (2-3 kPa) than the surroundings, and that the cell membrane above F-actin was stiffer (10-20 kPa) than the surroundings. In the elasticity map images of fixed astrocytes, on the other hand, the elasticity of the cells was found to be relatively uniform (200-700 kPa) irrespective of the inner structures of cells. These results show that images observed by AFM should be carefully examined in consideration of the force introduced to specimens and the elasticity of specimens to find out the real surface topography.     

Local and Global Properties of a Lead-Free Solder

Elastic and viscous properties including Young’s modulus, hardness, creep rate sensitivity, and fatigue resistance of Sn-1.2Ag-0.5Cu-0.05Ni lead-free solder have been investigated. The properties of bulk specimens and in situ solder balls are compared. Experiments show good correlations of Young’s modulus and creep rate sensitivity between conventional measurements and nanoindentation results on bulk specimens. Further mechanical properties of the beach-ball microstructure in solder balls are characterized by nanoindentation. The load–partial unload technique has been used to determine the variation in mechanical properties with increasing depth of penetration into the intermetallic inclusions in the in situ solder. The fatigue resistances of the bulk specimens and solder balls are compared by using the novel nanoimpact method. In comparison with bulk specimens, it is found that in situ solder has higher Young’s modulus, lower creep strain rate sensitivity, and better fatigue resistance. The effects of soldering and the scale differences strongly affect the mechanical and fatigue properties of in situ solder.     

Quantifying local stiffness variations in radiofrequency ablations with dynamic indentation

Elastographic imaging can be used to monitor ablation procedures; however, confident and clear determination of the ablation boundary is essential to ensure complete treatment of the pathological target. To investigate the potential for ablation boundary representation on elastographic images, local variations in the viscoelastic properties in radiofrequency-ablated regions that were formed in vivo in porcine liver tissue were quantified using dynamic indentation. Spatial stiffness maps were then correlated to stained histology, the gold standard for the determination of the ablation periphery or boundary. Regions of interest in 11 radiofrequency ablation samples were indented at 18-24 locations each, including the central zone of complete necrosis and more peripheral transition zones including normal tissue. Storage modulus and the rate of stiffening were both greatest in the central ablation zone and decreased with radial distance away from the center. The storage modulus and modulus contrast at the ablation outer transition zone boundary were 3.1 ± 1.0 kPa and 1.6 ± 0.4, respectively, and 36.2 ± 9.1 kPa and 18.3 ± 5.5 at the condensation boundary within the ablation zone. Elastographic imaging modalities were then compared to gross pathology in ex vivo bovine liver tissue. Area estimated from strain, shear-wave velocity, and gross pathology images were 470, 560, and 574 mm(2), respectively, and ablation widths were 19.4, 20.7, and 23.0 mm. This study has provided insights into spatial stiffness distributions within radiofrequency ablations and suggests that low stiffness contrast on the ablation periphery leads to the observed underestimation of ablation extent on elastographic images.     

SnAgCu体钎料及BGA焊球焊点纳米级力学性能

为了研究低银Sn-0.3Ag-0.7Cu无铅体钎料、BGA焊料小球和BGA焊点的力学行为,基于物理反分析的方法采用纳米压痕仪对其进行实验。从压痕载荷–深度曲线提取出弹性模量、硬度和蠕变速率敏感指数。结果表明:体钎料的杨氏模量和蠕变速率敏感指数大约是BGA焊料小球和BGA焊点的2.5倍,验证了尺寸效应理论。采用纳米压痕仪测出的体钎料维氏硬度(15.101HV)小于显微硬度计的测量结果(20.660HV)。     

Designer Biomaterials to Model Cancer Cell Invasion In Vitro: Predictive Tools or Just Pretty Pictures?

Metastasis is the leading cause of mortality in cancer patients. Underlying this process is the invasion and colonization of cancer cells into healthy tissues. Engineered hydrogel models of tumor microenvironments present an opportunity to understand the microenvironmental determinants of cellular invasion. The biochemical and mechanical cues, presented in the form of adhesion sites, degradable cues, matrix stiffness, and architecture, have significant effects on the extent of cancer cell migration, and the mechanisms employed by these cells to move through their matrix. Coculture with stromal cells such as cancer associated fibroblasts, endothelial cells, and immune cells that are associated with poor prognosis demonstrate that these cells exacerbate cancer cell invasion. With these models, researchers aim not only to recapitulate known cancer cell behaviors in a dish, but also to uncover new insights into mechanisms underlying these phenomena, paving the way for novel treatment strategies. In this perspective, the design of engineered models that are used to study cancer cell invasion and metastasis in vitro is discussed. To this end, the authors seek to understand and put into perspective: do these models reveal relevant mechanisms of cancer cell migration, or are they simply pretty pictures with little biological translatability?     

基于原子力显微镜的微桥机械特性测量

研究了基于原子力显微镜(AFM)的微桥机械特性的测量方法。通过微机电系统(MEMS)技术制备了可用静电力驱动进行机械振动的金属微桥。利用一套改进的商用AFM实验装置对测量方法进行了优化,并对微桥的共振频率进行了测量,所得实验结果与理论估算和仿真计算的结果基本一致。基于AFM的微桥机械特性的测量具有精度高和容易实现的特点,可作为测量平台扩展用于薄膜材料或微量液体的内耗、粘弹等性质的表征。