一种新型人工肌肉驱动机理与仿真研究

为了满足机器人驱动器宽范围速度输出,大的负载能力,高的输出精度等要求,提出了一种新型的人工肌肉驱动器。分析了这种人工肌肉的驱动机理,并对其进行了动力学建模与仿真。仿真结果表明,系统存在两种运行状态,在连续动态运行状态,最大速度可达到31mm/sec,最大的输出力达到150N,单步位移13.3μm以内;在准静态,最大速度可达到17.5mm/sec,输出力达到120N,单步位移11.8μm以内。系统的自锁力可达500N。同时分析了输入信号频率、负载、信号类型、相位等对系统输出速度的影响。研究结果表明该人工肌肉具有良好的驱动性能,为下一步物理样机的研制提供了很好的基础。     

Shivering during sleep: Relationship between muscle blood flow and fiber type composition

The present study considers in rabbit: i) the relationship between muscle blood flow (BF) increase and fiber-type composition during shivering; ii) the influence of the vigilance states (Quiet Wakefulness, QW; Synchronized Sleep, SS; Desynchronized Sleep, DS) on this relationship. The results show that muscle BF increase during shivering is proportional to the slow-twitch oxidative (SO) fiber component in QW and SS; in DS the proportionality is lost. This is in accordance with the disappearance of shivering, together with all thermoregulatory effector responses, in this sleep state. Another muscle circulation pattern occurring at low ambient temperature, the relationship between BF increase and muscle depth, also disappears in DS. This confirms that the integrative control of muscle circulation, like other integrative mechanisms, is impaired during DS.     

Pleiotropic effects of sonic hedgehog on muscle satellite cells

Muscle satellite cells are believed to form a stable, self-renewing pool of stem cells in adult muscle where they function in tissue growth and repair. A regulatory disruption of growth and differentiation of these cells is assumed to result in tumor formation. Here we provide for the first time evidence that sonic hedgehog (Shh) regulates the cell fate of adult muscle satellite cells in mammals. Shh promotes cell division of satellite cells (and of the related model C2C12 cells) and prevents their differentiation into multinucleated myotubes. In addition, Shh inhibits caspase-3 activation and apoptosis induced by serum deprivation. These effects of Shh are reversed by simultaneous administration of cyclopamine, a specific inhibitor of the Shh pathway. Taken together, Shh acts as a proliferation and survival factor of satellite cells in the adult muscle. Our results support the hypothesis of the rhabdomyosarcoma origin from satellite cells and suggest a role for Shh in this process.Received 23 February 2005; received after revision 2 May 2005; accepted 9 June 2005     

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。     

运动对骨骼肌α-actin基因表达影响的研究综述

依据骨骼肌肌动蛋白在机体运动能力上的重要作用和地位,从分子水平,主要论述了运动对骨骼肌肌动蛋白(-αactin)及其基因表达的影响和运动后恢复过程中骨骼肌α-actin及其基因表达的变化,以期为这方面的更深入研究作一参考。     

Serotonin-stimulated protein phosphorylation in aortic smooth muscle cells

Summary The effects of serotonin on the formation of inositol phosphates and protein phosphorylation were examined in cultured smooth muscle cells. Serotonin stimulated the formation of [³H]inositol monophosphate, [³H]inositol bisphosphate and [³H]inositol trisphosphate. This effect was prevented by 5-HT₂ specific antagonist, 6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid, 2-hydroxy-1-methylpropyl ester [Z]-2-butenedioate (LY53857). Serotonin stimulated the phosphorylation of many polypeptides, among which a 20 kDa polypeptide was the most prominent. The phosphorylation was also inhibited by LY53857. LY53857 alone produced no effects on protein phosphorylation. The 20 kDa polypeptides were also phosphorylated by the addition of 12-O-tetradecanoylphorbol-13-acetate. These results suggest that serotonin stimulates protein phosphorylation through 5-HT₂ receptors and possibly activates protein kinase C in intact vascular smooth muscle cells.Part of the data contained in this paper was presented at the 74th local meeting of the Japanese Society of Pharmacology at Kanagawa.     

运动与骨骼肌细胞凋亡及相关凋亡因子

运动中骨骼肌的疲劳或损伤与骨骼肌细胞凋亡存在着密切的关系.该文从氧自由基,线粒体钙离子代谢,线粒体膜电位的变化以及凋亡相关基因等机制方面综述了运动与骨骼肌细胞凋亡及其机制的新进展.     

一种医用椭圆环微带辐射器的研究

作者提出了一种医用椭圆环微带辐射器的分析设计方法,并给出辐射器加热的实验结果。通过改变椭圆环微带辐射器的形状参数即可获得形状、大小可调的加势图形,因而加热效率高,能满足各种临床治疗的需要,特别是在治疗浅表肿瘤、皮肤疾病以及促进伤口愈合等方面,更显示其实用价值。研究表明,理论分析结果和实验结果基本吻合。     

不同负荷运动对小鼠骨骼肌HO-1mRNA表达及血清CK、BUN的影响

目的:探讨不同负荷运动对小鼠股四头肌HO-1mRNA表达及血清CK、BUN的影响。方法:饲养、适应性运动BDF1小鼠,6周龄时随机分为对照组、30min、45 min、180min中等强度运动组;45 min低强度、高强度运动组,利用RT-PCR法测定各组HO-1mRNA表达情况,利用动力学法测定血清CK;利用两点法测定血清BUN浓度。结果:(1)中等强度运动可诱导小鼠股四头肌HO-1mRNA表达增加,45min运动组HO-1mRNA诱导最明显;(2)运动诱导HO-1mRNA表达增加与运动时间、运动强度无依赖关系;(3)血清CK、BUN随运动时间、运动强度变化发生改变。结论:运动可以诱导小鼠骨骼肌HO-1mRNA表达增加。     

家兔在发育过程中外侧腓肠肌内MyHCs变化与诱发电位的关系

 为研究在生后不同年龄组家兔外侧腓肠肌各亚体肌纤维MyHCs变化与诱发电位的关系,探讨生后发育期间肌纤维MyHCs组成和作用差异与表型之间的相关联系,采用电生理记录仪结合十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS PAGE）检测外侧腓肠肌各亚体。结果表明中间亚体在刺激时各年龄组的峰值电压基本相同,而外侧亚体和内侧亚体分别有些变化。同时发现成年家兔的持续时间都较幼年的长,这可能与各亚体的肌纤维型构成比例有很大关系。外侧腓肠肌各亚体的肌球蛋白重链异构体（MyHCs）电泳条带分别显示MyHCsⅡa、Ⅱd（或Ⅱx）、Ⅱb、Ⅰ共4种,对应于骨骼肌纤维表型ⅡA型（FOG型）、ⅡX（FO型）、ⅡB型（FG型）及Ⅰ型（SO型）4类。