仿生气动肌纤维静态特性建模与实验研究

开展气动肌纤维静态特性建模与实验研究,综合考虑气动肌纤维端部变形、摩擦力、死区气压等对其静态特性的影响,提出一种气动肌纤维静态特性数学模型.搭建气动肌纤维静态特性实验平台,开展气动肌纤维及气动肌纤维束静态特性等长实验、等张实验及等压实验,对比分析不同规格参数的气动肌纤维及气动肌纤维束的静态特性.基于实验所得的等压特性曲线,提出一种气动肌纤维束实验模型,由大量实验数据辨识获得符合实际情况的气动肌纤维及气动肌纤维束的静态特性数学模型,为气动肌纤维驱动微型仿生机器人的精准控制奠定基础.     

单根蛙类骨骼肌纤维去膜方法研究

本文详细介绍去除单根蛙类骨骼肌纤维细胞膜的化学和机械方法，并就这两种去膜方法得到的去膜肌纤维的特点分别进行了较全面的比较和分析，本文还提出了一种鉴定去膜效果的快速直观的张力测试手段。     

九龙牦牛肌肉组织学特性研究(初报)

肌纤维的细度与密度以及肌肉肌纤维与结缔组织之比例,在一定程度上反映了肉的品质。作者于1989年研究了九龙牦牛的斜卡、洪坝两类系14头2.5～6.5岁以上健康牦牛背最长肌的组织学特性,并与其它牛种相同部位肌肉组织进行比较。结果表明,九龙牦牛肌纤维直径为41.94～53.66μ,肌纤维密度为301.6～336.45(N/mm~2),并测定了不同年龄九龙牦牛背最长肌内肌纤维与结缔组织体积比(％)。在一定程度上表明了九龙牦牛的肉质细嫩,品质良好,为九龙牦牛作为肉用型牦牛品种的选育提供了一定的理论依据。     

胎儿食管肌层骨胳肌纤维类型的观察

取引产后死亡的正常胎儿(32～40W,10个)食管,将其等分为上、中、下三段。对食管肌层骨骼肌纤维类型,进行光镜酶(SDH)组织化学和一般透射电镜观察。结果表明,胎儿上1/3段食管肌层由骨骼肌纤维构成;其肌纤维经SDH染色、光镜观察显示红肌纤维的结构特点;然而在透射电镜下观察则具有与白肌纤维相近的超微结构特征。这一研究结果,必将为肌纤维分类的多元性提供有价值的参考,同时对进一步探索食管的生理功能也将有所帮助。     

pH值对应用mATP酶法进行梭外肌纤维分型的影响

目的 探讨酸性和碱性预孵育处理，对应用mATP酶法进行梭外肌纤维分型的影响。方法 mATP酶法。结果 ①用pH4．3的预孵育液孵育后，梭外肌纤维可分为Ⅰ，ⅡA，ⅡAB及ⅡB型；pH4．6预孵育后，梭外肌纤维可分为Ⅰ，ⅡA和ⅡB型；pH9．4和pH10．4预孵育液条件下，梭外肌纤维均可分为Ⅰ型和Ⅱ型肌纤维，且Ⅰ型肌纤维的比例略低于酸法。②预孵育液和作用液的pH值随时间的延长均有下降的趋势。结论 用mATP酶法研究梭外肌纤维的分型时应当说明并严格把握预孵育液的pH值。     

损伤肌纤维的椭圆偏振法研究

该文利用椭圆偏振技术研究骨骼肌受损伤时肌纤维内部分子运动状态的变化。实验测得，无论是完整的单根肌纤维还是去膜的单根肌纤维，衍射光的退偏率ｒ都呈增大的趋势。这一结果，可以用它造成肌纤维的膜损伤，破坏了兴奋耦联系统，导致肌质网释放钙离子的能力下降，从而使肌动蛋白上结构位点暴露减少，因此与横桥结合的几率小来加以说明。对损伤肌肉的完整单根肌纤维的张力测试结果证明这一假设是合理的。     

3个年龄组的腓肠肌纤维型分布

实验采用肌球蛋白ATP酶染色法检测了 8例男性 (3～ 16岁 )、8例男性 (18～ 45岁 )、5例男性 (5 0～ 6 5岁 )腓肠肌各亚部肌纤维型的构成和分布 ,结果表明 ,不同年龄组Ⅰ型纤维比例不同 ,分别为 (5 2 .5± 9) %、(5 6 .5±6 ) %、(5 8.4± 4.8) %。其中 3～ 16岁年龄组的Ⅰ型纤维比例显著高于其他两年龄组 (P <0 .0 5 ) ;而后两年龄组的Ⅰ型纤维比例在统计学上无显著差异 ,但随着年龄的增长 ,Ⅰ型纤维比例增加。从外侧头和内侧头亚部分析 ,只有内侧头深部 (3～ 16岁 )的Ⅰ型纤维比例 (5 2 .9± 8) %显著高于其它两年龄组 (P <0 .0 5 ) ;外侧头深部 (3～ 16岁 )的Ⅰ型纤维比例 (5 2 .3± 7.2 ) %显著高于其它两年龄组 (P <0 .0 5 )。而其它内、外侧头亚部 3年龄组在统计学上无显著差异。说明 3～ 16岁年龄组和后两年龄组肌纤维型比例有较大差异 ;18～ 45岁、5 0～ 6 5岁年龄组之间Ⅰ型纤维比例和内、外侧头各亚部之间Ⅰ型肌纤维比例差异不显著。本文还对不同年龄组肌纤维构成与肌功能适应的问题作了讨论。     

脉红螺心肌纤维的形态学研究

作者从１９９０年３月至１９９３年６月，通过光镜和电镜，观察了脉红螺心肌纤维的形态结构，并与其它软体动物和脊椎动物进行了比较。脉红螺心肌纤维细长，无肌节和周期性横纹，排列不规则，纵横交错，在两条心肌纤维连接处有类似闰盘的结构。肌原纤维由粗丝和细丝构成，两者平行相间排列，对位不整齐。线粒体发达，成簇分布在肌膜下或肌原纤维间，其间有脂褐素颗粒存在，肌质网不甚发达，成泡状结构，分布在肌膜下。大量糖元颗粒存     

热诱导去膜肌纤维收缩机理的椭园偏振法研究

利用自制的磁光调制瞬态椭园偏振仪，发现通过单根青蛙去膜肌纤维的衍射光的退偏率是温度的函数，当温度在３０℃左右时，退偏率呈现极小值，肌纤维张力呈突然上升趋势，而衍射光强度则随之下降，与完整青蛙肌纤维同样效应的实验结果相比较，我们认为这是由于温度接近３０℃时肌质网释放的钙离子浓度大于扩散到肌纤维内部的ＥＧＴＡ，因而游离的钙离子促使横桥由弱耦合向强耦合过渡，退偏率下降，张力增大，光强减弱，温度进一步提高     

肌纤维母细胞瘤

目的:观察肌纤维母细胞瘤形态、组织化学及电镜特点。方法:对1例结肠系膜肌纤维母细胞瘤进行光镜、电镜观察及组织化学染色。结果:HE染色可见瘤细胞由大量成束的梭形细胞及少量星芒状细胞构成,伴淋巴细胞浸润;VG染色瘤组织呈红色和黄色的混合色;电镜可见胞浆内含肌丝及胶原原纤维。结论:肌纤维母细胞瘤兼具纤维母细胞及平滑肌细胞形态及功能特点,可能来源于间充质细胞,可以为良性病变,具有局部复发倾向。     

PH值对应用肌球蛋白 ATP酶法进行梭内肌纤维分型的影响

探讨酸性和碱性预孵育处理，对应用肌球蛋白ATP酶法进行梭内肌纤维分型的影响。采用肌球蛋白ATP酶法。PH4．3和PH4．6预孵育液孵育后，梭内肌纤维中的核袋纤维染色呈阳性，核链纤维染色相对较浅；PH9．4预孵育后，核袋与核链纤维均呈阳性或强阳性；PH10．4预孵育后，核袋1纤维呈阴性，核袋2纤维呈阳性，核链纤维呈强阳性。结论是：用mATP酶法研究梭内肌纤维的分型时，预孵育液的PH值对分型结果有显著影响，应当说明并严格把握预孵育液的PH值。     

Synthesis of fast myosin induced by fast ectopic innervation of rat soleus muscle is restricted to the ectopic endplate region

Skeletal muscle fibres, long multinucleated cells, arise by fusion of mononucleated myoblasts to form a myotube that matures into the adult fibre. The two major types of mature fibre, fast and slow fibres, differ physiologically in their rate of isotonic shortening. At the molecular level these type-specific physiological properties are ascribed to different isoforms of myosin, a major protein involved in shortening. Differentiation of fast and slow fibres seems to be under the control of motoneurones, and mature fibres are innervated by only one motoneurone. When rat soleus muscle (SOL, a slow muscle) is dually innervated with a fast nerve, it acquires some properties of a fast muscle, that is, low sensitivity to caffeine and high glycogen content. We report here that in dually innervated soleus muscle the foreign fast nerve induces synthesis of fast isoforms of myosin, but only in the segment of the muscle fibre that is close to the foreign endplate. The localized influence of the nerve endplates suggest that factors controlling the phenotypic expression of the muscle fibre have a short range of activity.     

AN INVESTIGATION OF THE BENDING FATIGUE OF MODIFIED PPTA FIBRE

PPTA fibres have high axial tensile strength,but the transverse links at the macromolecularlevel of the fibres are low.The high orientation and crystallization of the PPTA fibres leads to alow resistance to bending fatigue.A comparative study on fatigue behaviour of PPTA fibres and modified PPTA fibres weremade by rotating fibre over a pin.The resistant properties of the PPTA fibre to the bending fa-tigue are low,but can be improved by modification.The morphological differences of the deformation processes of the PPTA fibres and modi-fied PPTA fibres as they are tensioned in a monofilament from after being knotted are shown.The properties of resistance to bending fatigue of the different PPTA fibres can be evaluatedby comparing the morphologies of the tensile broken ends of these fibres after knotting.     

Fast and slow myosin in developing muscle fibres.

Slow and fast isoenzymes of myosin coexist in all the fibres of a fast-twitch mammalian muscle during early development. They later become segregated into different populations of fibres. Slow myosin is most abundant when the speed of contraction of the muscle is slow and the fibres are multiply innervated; its synthesis in the majority of the fibres seems to be 'switched off' when the speed of contraction increases and the fibres become innervated by single motoneurones.     

耐力训练对大鼠骨骼肌收缩蛋白的影响

目的:探索运动训练对大鼠骨骼肌收缩蛋白的影响,为进一步研究其蛋白水平提供依据。方法:选用清洁级健康雄性Sprague-Dawley(SD)大鼠20只,6周龄,体重135-150g,随机分为2组。A:安静对照组,n=10,B:运动训练组,n=10。运动训练组:进行持续性大运动量跑台训练8周。实验使用SDS-PAGE(十二烷基硫酸钠-聚丙烯凝胶电泳),浓缩胶浓度5%,分离胶浓度10%,电泳电压160V,时间200min。结果:在骨骼肌收缩蛋白SDS-PAGE后,运动训练组电泳图谱上出现大量新的条带,分子量范围为43-200 kDa。结论:本运动模型下,在骨骼肌收缩蛋白SDS-PAGE后,运动训练组图谱上出现大量新的蛋白条带,这些新的条带是肌肉蛋白质的降解产物,还是为了修复运动损伤而合成的新的蛋白质片段,还有待后续研究。     

电镜对纺织纤维归类识别的观察

刑侦现场取得的纺织物常常是细小的纤维,要正确判断纤维的分类可以使用电子显微镜,电子显微镜拍照的图像可以对不同纺织物种类进行检查对比。我们建立的电子显微图像数据库对刑侦工作中区分纺织纤维的类别是适用的。     

Why animals have different muscle fibre types

Animals have different muscle fibre types: slow fibres with a low maximum velocity of shortening (Vmax) and fast fibres with a high Vmax. An advantage conferred by the use of different fibre types during locomotion has been proposed solely on the basis of their in vitro properties. Isolated muscle experiments show that force generation, mechanical power production and efficiency are all functions of V/Vmax, where V is the velocity of muscle shortening. But it is not known whether animals actually use the different fibres at shortening velocities that are optimal for mechanical power production and efficiency. Here we compare the V of muscle fibres during locomotion with their Vmax. This comparison shows that during slow locomotion, the slow fibres shorten at a velocity that gives peak mechanical power and efficiency and the fast fibres shorten at their optimal velocity when powering maximal movements. Our results also show that maximal movements are impossible without fast fibres because the slow ones cannot shorten rapidly enough.     

Conversion of mdx myofibres from dystrophin-negative to -positive by injection of normal myoblasts

An important corollary to the recent advances in our understanding of the primary cause of Duchenne muscular dystrophy, is the validation of genuine genetic homologues as animal models of the disease in which potential therapies can be tested. The persistent skeletal muscle necrosis that characterizes human Duchenne muscular dystrophy is also seen in the mdx mouse and is, in both, a consequence of a deficiency of dystrophin, probably within the muscle fibres themselves. As injected muscle precursor cells of one genotype can fuse with host muscle fibres of a different genotype and express the donor genes, we decided to test grafts of normal muscle precursor cells to see if they could induce synthesis of dystrophin in innately dystrophin-deficient mdx muscle fibres. We show that injected normal muscle precursor cells can fuse with pre-existing or regenerating mdx muscle fibres to render many of these fibres dystrophin-positive and so to partially or wholly rescue them from their biochemical defect.     

膀胱逼尿肌的组织及生理学概述

膀胱逼尿肌在组织结构、超微结构、收缩功能、舒张功能、自律性及电生理学方面具有自身的特点.在组织结构上,通过平滑肌肌束之间的交叉聚集使膀胱逼尿肌成为一个统一的整体;在超微结构上,通过逼尿肌肌细胞之间的中间连接使平滑肌肌束成为一个有机的组合;在收缩功能上,膀胱逼尿肌的特点是自发性收缩和神经性收缩的动态平衡;在舒张功能上,膀胱逼尿肌的特点是应力性舒张和神经性舒张的协调一致;在自律性方面,膀胱逼尿肌具有产生自发性动作电位的能力以及触发自主性收缩的能力;在电生理方面,膀胱逼尿肌的肌膜去极化引起的动作电位通过作用于钙通道形成Ca2+内流,实现了兴奋与收缩之间的耦联.