A New Way of the Skeletal Metals Synthesis

1 Results Strongly disordered metals with the high chemical and catalytic activity are often called as skeletal metals.Usually for their preparation the metallides of d-metal (which afterwards will be left in the “skeleton“) and chemically active component(s) are firstly synthesized.Then the last one(s) is (are) removed by the leaching with aqueous solutions of alkalis or carbonates.However,this method sometime fails,first of all,for the reactions,which should be realized in non-aqueous conditions.In th...     

Studies of a key protein in the mechanism of the excitation-contraction coupling process of frog skeletal muscle,using phenylglyoxal

The excitation-contraction (E-C) coupling process in single twitch fibres from frog toe muscle was inhibited selectively by phenylglyoxal (PGO), a specific guanidyl modifying reagent. A new protein (31.5 kDa), which has PGO-binding ability and seems to play a key role in the E-C coupling process, was solubilized from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) of frog skeletal muscles, using¹⁴C-PGO. The monoclonal antibody against this protein applied extracellularly inhibited the E-C coupling process of the single fibres. This protein appears to constitute the very first step of input for E-C coupling. It is considered to behave as an indispensable part of an electrometer to measure membrane potentials. Therefore, the name electrometrin is suggested for the new protein.     

猪骨形态发生蛋白体外诱导小鼠肌组织成骨的实验研究

这项研究借助体外培养技术，动态观察猪骨形态发生蛋白对小鼠骨骼肌增殖分化的作用。实验结果表明，猪骨形态发生蛋白可体外诱导新生鼠骨骼成骨，但对成年鼠骨骼肌无诱导作用；ＲＰＭＩ－１６４０培养基可使软骨细胞表型得以充分表达；建立的实验模型对鉴定骨形态发生蛋白活性有一定实用价值。此外，在体外诱导肌组织成骨实验过程中还观察到其它学者未曾报道过的软骨溶解期。     

浅议运动后骨骼肌疲劳的原因

疲劳是人或动物对体力训练失去反应能力．内环境发生紊乱的具体表现，本文阐述了引起疲劳的几个主要原因．     

MTMR14基因缺失促进小鼠成肌细胞增殖和分化

为研究磷酸肌醇磷酸酶肌管相关蛋白14(MTMR14)在骨骼肌发生中的作用,通过组织切片和细胞培养技术研究了MTMR14敲除对骨骼肌的组织结构、成肌细胞分化和增殖的影响.结果表明:MTMR14敲除小鼠的腓肠肌和比目鱼肌的结构较同窝野生型小鼠产生了明显变化,MTMR14敲除小鼠的成肌细胞的分化和增殖成肌小管过程较野生型显著加快.MTMR14基因敲除后小鼠肌管细胞中平均细胞核数显著增加.故MTMR14基因缺失/敲除导致骨骼肌组织结构异常,干扰了骨骼肌肌肉发生过程中的成肌细胞的增殖和分化.     

西宁地区青少儿骨龄评价

本文采用ＣＨＮ法对出生地为西宁地区的３０９５名７—１８岁汉族健康有少儿骨发育等级进行了评价，表明高原地区青少儿较同方法评定的平原青少儿骨发育成熟度明显延缓，这与测量身高、体重所得的结论一致并更加精确。本文建立的青海标准既是对全国标准的修正和补充、又是评价高原青少儿骨龄和发育水平等的重要依据。     

Frequency-dependent effect of verapamil on rat soleus muscle

Summary In the presence of verapamil (0.1 mM) rat soleus muscle fibers failed to generate action potentials with overshoots. In fibers with their V_m set to a local level of –90 mV, verapamil produces a gradual reduction in the amplitude of the repetitive action potentials; this effect is more pronounced at high rates of stimulation (100 Hz). Our results suggest a local anesthetic action of this drug that could contribute with its calcium channel blocking effect to the diminished mechanical tension observed in the presence of the drug.Acknowledgments. We thank A. Losavio and M. Stefanolo for technical assistance. This work was supported by grants from CONICET and SUBCYT, Buenos Aires, Argentina and Muscular Dystrophy Association, USA.     

Effects of nitric oxide on the contraction of skeletal muscle

A review of the literature suggests that the effects of nitric oxide (NO) on skeletal muscles fibers can be classified in two groups. In the first, the effects of NO are direct, due to nitrosation or metal nitrosylation of target proteins: depression of isometric force, shortening velocity of loaded or unloaded contractions, glycolysis and mitochondrial respiration. The effect on calcium release channels varies, being inhibitory at low and stimulatory at high NO concentrations. The general consequence of the direct effects of NO is to ‘brake’ the contraction and its associated metabolism. In the second group, the effects of NO are mediated by cGMP: increase of the shortening velocity of loaded or unloaded contractions, maximal mechanical power, initial rate of force development, frequency of tetanic fusion, glucose uptake, glycolysis and mitochondrial respiration; decreases of half relaxation time of tetanus and twitch, twitch time-to-peak, force maintained during unfused tetanus and of stimulus-associated calcium release. There is negligible effect on maximal force of isometric twitch and tetanus. The general consequence of cGMP-mediated effects of NO is to improve mechanical and metabolic muscle power, similar to a transformation of slow-twitch to fast-twitch muscle, an effect that we may summarize as a ‘slow-to-fast’ shift.     

瓦砾替代卵石骨料对混凝土抗压强度的影响

混凝土中加入部分瓦砾作为卵石骨料的替代物，能使水泥浆进入到碎砖孔隙当中，减低界面水的形成，阻碍微裂纹的产生。同时废旧瓦砾集料与凝胶材料的结合较好，能够提高试块的抗压强度。卵石含量60％，碎砖含量40％试块的抗压强度最高。利用废旧瓦砾部分替代混凝土骨料制成的绿色混凝土材料，较好地解决了环保与建设的矛盾，同时也为合理利用城市建筑垃圾提供了一条有效途径。     

运动对骨骼肌中胰岛素样生长因子I影响的研究进展

胰岛素样生长因子I(IGF-I)是一类促进细胞生长,具有胰岛素样代谢效应的因子,与运动能力密切相关。分析了近年来关于胰岛素样生长因子在运动、常氧运动、低氧运动不同应激下的变化情况的文献资料。对胰岛素样生长因子研究进展进行了阐述。对于IGF-I与低氧训练关系的研究,有助于提供低氧训练的评定指标,为低氧训练提供科学的理论指导。