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71.
72.
孙燕 《中央民族大学学报(自然科学版)》2003,12(3):251-253
本文给出一种将工艺图纸或机械图纸一类的彩色图像矢量化的算法,它对提高工艺图或机械图的编辑、计算效率等具有重要的意义。 相似文献
74.
文章通过对舞蹈解剖学的系统阐述,说明人体各个器官、系统的形态、结构特征的相互关系。以及舞蹈训练对人体形态结构产生的影响,初步分析了运用解剖学的基础知识分析舞蹈动作的方法,以及运用舞蹈解剖学知识,预防身体损伤的方法。 相似文献
75.
G. Bailin 《Cellular and molecular life sciences : CMLS》1984,40(11):1185-1188
Summary In smooth muscle the Mr 20,000 light chain of myosin is phosphorylated by a calmodulin-dependent protein kinase. It consists of 2 subunits: calmodulin, an acidic protein of Mr 17,000 that binds 4 moles of Ca2+; and a larger protein of Mr circa 130,000. Activation of the kinase is dependent upon their association in the presence of Ca2+. Cyclic AMP-dependent protein kinase phosphorylation of the myosin light chain kinase occurs at 2 sites. It decreases the affinity of the kinase for calmodulin and a reduction in the rate of light chain phosphorylation occurs. The kinase has an overall asymmetric shape composed of a globular head and tail region for the skeletal muscle enzyme. Trypsin digestion of this kinase releases a fragment of Mr 36,000 from the globular region that contains the catalytic and calmodulin binding sites. Chymotrypsin digestion of the kinase from smooth muscle generates a fragment of Mr 80,000 that does not contain the calmodulin binding or cyclic AMP-dependent protein kinase phosphorylation sites. It is a Ca2+-independent form of the kinase that phosphorylates the light chain of myosin. These structural features indicate a regulatory role for the kinase in smooth muscle phosphorylation and contraction. 相似文献
76.
K. R. Weiss V. Březina E. C. Cropper S. L. Hooper M. W. Miller W. C. Probst F. S. Vilim I. Kupfermann 《Cellular and molecular life sciences : CMLS》1992,48(5):456-463
Despite their ubiquitous presence in the central and peripheral nervous systems, the behavioral functions of peptide co-transmitters remain to be elucidated. The marine molluscAplysia, whose simple nervous system facilitates the study of the neural basis of behavior, was used to investigate the role of peptidergic co-transmission in feeding behavior. Several novel modulatory neuropeptides were purified, and localized to identified cholinergic motorneurons. Physiological and biochemical studies demonstrated that these peptides are released when the motorneourons fire at frequencies that occur during normal behavior, and that the peptides modify the relationship between muscle contraction amplitude and relaxation rate so as to maintain optimal motor output when the intensity and frequency of feeding behavior change. 相似文献
77.
一块黑砂皮波菜绿色的翡翠 ,经能谱、电镜、红外光谱分析、镜下鉴定及物性测量 ,确定是一块未经处理的 A货翡翠 ,但其外层黑色皮壳上的沥青光泽的细鳞片确是有机质 ,是人为所致。 相似文献
78.
N. Ishii 《Cellular and molecular life sciences : CMLS》1986,42(7):810-812
Summary The maximal unloaded shortening velocity (Vmax) of smooth muscle cells isolated from the pedal retractor muscle ofMytilus was more than twice as large as that of the whole muscle, suggesting the presence of extracellular components which resist the contraction of the whole muscle. The Vmax of the isolated cells was almost constant at cell lengths ranging between 0.5 and 0.8310 (10, optimal length for tension generation) indicating that the intracellular resistance to contraction is negligible within this range of lengths. 相似文献
79.
O. V. Subramanyam 《Cellular and molecular life sciences : CMLS》1984,40(12):1423-1424
Summary Blood sugars and foot muscle glycogen were measured in the mussel,L. marginalis after ablation of the cerebral ganglia, and in mussels injected with cerebral ganglionic extract 3 h after ablation. There is a rise in the blood sugar and decrease in foot muscle glycogen 3 h after operation, but no change in sham-operated controls. The effect of ablation is reversed by injecting brain extract into ablated mussels. No such effect could be seen in the controls. The results are suggestive of the presence, in the cerebral ganglia, of a hypoglycaemic factor similar to insulin. 相似文献
80.
T. A. Robertson J. M. Papadimitriou M. D. Grounds 《Cellular and molecular life sciences : CMLS》1992,48(4):394-395
In this report we demonstrate for the first time that differentiating myogenic cells, geographically located between the plasmalemma and external lamina of myofibres in the satellite cell position3, can fuse directly with the plasmalemma of undamaged segments of mature myofibres. 相似文献