气动人工肌肉驱动球面并联机器人的位置控制研究

研究将气动人工肌肉驱动器应用于柔索驱动三自由度球面并联机器人机构,介绍了该机器人的运动学模型,提出一种简便的轨迹规划方法,在建立的实验测控系统中,应用含并联机器人的位置逆解和对气动人工肌肉的智能PID控制的位置控制算法,实现对机器人末端的位置控制,通过机器人的位置正解验证了位置控制的控制效果.     

水下软体机器人柔性驱动方式及其仿生运动机理研究进展

 随着水下作业要求的增加以及软体机器人技术的发展,水下软体机器人的研究成为水下机器人的一个前沿方向。用人工肌肉实现驱动控制并能实现仿生运动的水下软体机器人成为相关领域的研究热点。本文介绍现有水下软体机器人中7类人工肌肉驱动方式,再根据水下软体机器人推进形式,按5种仿生运动形式介绍了现有的水下软体机器人,最后展望了水下软体机器人未来在水下勘探的应用前景。     

解冻方式对冷冻泥鳅肌肉组织理化性质和微观结构的影响

以解冻损失率、蒸煮损失率、解冻pH值、蛋白质溶解性、水分分布等为指标,研究4 ℃解冻、室温解冻、流水解冻、微波解冻、超声解冻5 种解冻方式对冷冻泥鳅肌肉组织理化性质和微观结构的影响,并分析了各指标之间的相关性。研究结果表明:不同解冻方式对泥鳅鱼肉解冻损失率存在显著性差异(P<0.05);流水解冻对泥鳅鱼肉解冻损失率、蒸煮损失率、pH值、蛋白质的溶解性影响最小;对各指标进行相关性分析,发现肌浆蛋白的溶解度与其他指标的相关性较好,都呈显著相关;采用扫描电镜观察解冻后的鱼肉的微观结构,解冻后泥鳅鱼肉的肌肉纤维间隙变大,其中,超声解冻的间隙最大,微波解冻后出现部分蛋白变性;采用低场核磁共振测定横向弛豫时间,发现解冻后泥鳅鱼肉的水分状态和含量发生变化。5种解冻方式中,流水解冻后的泥鳅鱼肉解冻损失率和蒸煮损失率最小,质构特性好,最终确定冷冻泥鳅的最优解冻方式为流水解冻。     

竞技武术套路运动员肌肉力量的等速测试

通过等速肌力测试法、数理统计法等对河北省优秀竞技武术套路运动员各部位肌肉力量进行了测试.结果发现,竞技武术套路运动员肩关节肌肉力量屈肌大于伸肌,有别于其他研究的运动项目;通过对肩关节、髋关节、膝关节部位肌肉力量的综合比较,表明运动员上下肢肌力较为均衡.     

三种麻醉剂对离体骨骼肌收缩性影响的比较研究

目的：探讨三种不同的麻醉剂对蟾蜍离体腓肠肌收缩性的影响．方法：把剥制好的离体腓肠肌标本先浸泡在任氏液中，用BL-410生物机能实验系统记录最适刺激下的单收缩曲线；然后换上不同浓度的麻醉剂浸泡8min，记录单收缩曲线．分别测定单收缩的最大收缩力、收缩速率、舒张速率、抑制率．结果：三种不同的麻醉剂对蟾蜍离体腓肠肌收缩能力均有不同程度的抑制作用，低浓度下氨基甲酸乙酯的抑制作用最强，其次是水合氯醛，戊巴比妥钠的抑制作用最小．中、高浓度下水合氯醛的抑制作用最强，其次是氨綦甲酸乙酯，戊巴比妥钠的抑制作用最小．     

维甲酸对胎儿动脉导管和动脉平滑肌细胞的增殖及信号传导通路的影响

目的研究维甲酸在体外对胎儿动脉导管、主动脉及肺动脉平滑肌细胞的增殖活性和其相应的细胞信号传导通路—ERK1/2细胞信号传导通路的影响。方法6例经水囊引产后的胎儿动脉导管、主动脉及肺动脉平滑肌细胞经原代培养及传代培养(5代以内),通过免疫组织化学方法和ELISA方法检测维甲酸对细胞增殖核抗原的表达和ERK1/2细胞信号传导通路的OD值,并与对照组进行比较。结果①胎儿动脉导管平滑肌细胞:维甲酸组PCNA表达升高,同时伴有ERK1/2的OD值升高。②主动脉平滑肌细胞:维甲酸组PCNA表达降低,同时伴有ERK1/2的OD值降低。③肺动脉平滑肌细胞:维甲酸组PCNA和ERK1/2的OD值与对照组相比,无显著性差异(P>0.05)。结论不同来源的平滑肌细胞有着不同的生物学特性,对维甲酸的反应截然不同。     

物理新技术改进肉类肌肉质构的机理与应用

肉品肌肉的质构是其主要的感官指标之一,它在很大程度上决定了肉食品的口感与可食性。根据质构在肌肉成熟的生理生化过程中的变化和特征,多种物理技术可以有效地对肌肉质构进行改进,分析了高压技术、真空滾揉技术、电剌激和高压电场技术、超声波技术等 4种物理新技术的特点和改进肌肉质构的作用机理,介绍了它们的效果和应用前景。     

The potency of heparin-like activity of glycosaminoglycans released by human endothelial cells in culture

Summary Glycosaminoglycans isolated from culture medium conditioned by human endothelial cells showed heparin-like antithrombin III cofactor activity measured by Xa inhibition. Their activity was relatively weak, 0.1% of the potency of heparin, but was approximately 5-fold more potent than that of glycosaminoglycans derived from vascular smooth muscle cells.     

Single nucleotide polymorphism analysis in chicken growth hormone gene and its associations with growth and carcass traits

In this experiment, F2 chicken derived from Broilers crossing to Silky are used to study the effect of growth hormone gene on growth and carcass traits. The partial gene is amplified by two pairs of primers, and single nucleotide polymorphism (SNPs) is detected by the technique of PCR-RFLP (restriction fragment length polymorphism), and then confirmed by DNA sequencing. The mutations are found in intron 3 and intron 4 respectively, and can be clarified by digestion with EcoRVand Msp I. The results of least square analysis indicate that the gene has significant association with some carcass traits, such as breast muscle weight, breast muscle rate, abdominal fat rate, and has no association with other growth and carcass traits, such as live weight, carcass weight, eviscerated yield with giblet, eviscerated yield, leg muscle weight, heart weight, liver weight, abdominal fat weight, chest angle width, head and neck weight,shank and claw weight, wing weight, muscular stomach weight, glandular stomach weight, ovary or testicular weight, shank girth, small intestine length, 1-week body weight, 6-week body weight, 12-week body weight, etc. These results demonstrate that GH gene could be a genetic locus or linked to a major gene significantly affecting the growth and carcass traits in chicken.     

The expression levels of three raft-associated molecules in cultivated vascular cells are dependent on culture conditions

Relaying a signal across the plasma membrane requires functional connections between the partner molecules. Membrane microdomains or lipid rafts provide an environment in which such specific interactions can take place. The integrity of these sites is often taken for granted when signalling pathways are investigated in cell culture. However, it is well known that smooth muscle and endothelial cells undergo cytoskeletal rearrangements during monolayer culturing. Likewise affected – and with potentially important consequences for signalling events – is the organization of the plasma membrane. The expression levels of three raft markers were massively upregulated, and raft-associated 5-nucleotidase activity increased in conventional monolayer cultures as compared with a spheroidal coculture model, shown to promote the differentiation of endothelial cells. Our data point to a shift of raft components in monolayer cultures and demonstrate potential advantages of the spheroid coculture system for investigation of raft-mediated signalling events in endothelial cells.Received 4 August 2003; received after revision 18 September 2003; accepted 25 September 2003