进行动物实验应遵循的基本原则

１引言尽管由于国家、文化背景和宗教信仰不同，人们对待动物的态度千差万别，但是，以科学研究为目的使用动物时，有一条根本原则，即负责任、合乎道德地使用动物。使研究结果具有可重复性、可比性、科学性。在科学探索中使用动物是一种贡献，而不是权力，对这种贡献必须...     

温度和应变率对拉伸载荷下记忆合金本构关系的影响

用于高温Split Hopkinson Bar(SHB)试验的新型快速加热电炉，可在1min左右将试件加热至500度，最高可加热至1000度，且金属材料和非金属材料均可加热，在20－800度和0．00208－350s^-1范围内研究了温度和变率对拉伸载荷下铁基形状记忆合金本构关系的影响，结果表明，随着应变率提高，材料强度提高，延伸率降低，材料强度，延伸率及应变率敏感性随温度升高而降低。     

Mechanical and biochemical characterization of the contraction elicited by a calcium-independent myosin light chain kinase in chemically skinned smooth muscle

Summary The contraction induced by a Ca²⁺-independent myosin light chain kinase (MLCK-) was characterized in terms of isometric force (F_o), immediate elastic recoil (SE), unloaded shortening velocity (V_us), shortening under a constant load and ATPase activity of chemically skinned smooth muscle preparations. These parameters were compared to those measured in a Ca²⁺-induced contraction to assess the nature of cross bridge interaction in the MLCK-induced contraction. F_o developed in chicken gizzard fibers as well as SE were similar in contractions elicited by either agent. V_us in the contraction induced by MLCK-(0.36 mg/ml) was similar though averaged 39.3±8.9% less than V_us induced by Ca²⁺ (1.6x10^–6M) in the control fibers. Addition of Ca²⁺ (1.6x10^–6M) to a contraction induced by MLCK-resulted in small increases in both F_o and V_us. Shortening under a constant load was similar for both types of contractions. The contraction induced by MLCK-was accompanied by an increased rate of ATP hydrolysis. The MLCK-induced contraction is thus kinetically similar though not identical to a contraction induced by Ca²⁺. We conclude that with respect to actin-myosin interaction, MLCK- and Ca²⁺-induced contractions are similar.     

Hemoglobin causes both endothelium-dependent and endothelium-independent contraction of the pig coronary arteries, independently of an inhibition of EDRF effects

Hemoglobin is widely used as an inhibitor of EDRF effects. Hemoglobin contracts pig coronary arteries in vitro. However, during this contraction, effects of substance P and bradykinin which act via the EDRF are not inhibited. This means that the hemoglobin contraction is not caused by inhibition of the EDRF. This contraction is caused by a substance released from the endothelium, and by eicosano?ds released from the smooth muscles.     

Heritability of locomotor performance and its correlates in a natural population

Summary Locomotor capacities and their physiological bases are thought to be of considerable selective importance in natural populations. Within this functional complex, organismal performance traits (e.g., speed, stamina) are expected to be of more direct selective importance than their suborganismal determinants (e.g., heart size). Quantitative genetics theory predicts that traits of greater selective importance should generally have lower heritabilities at equilibrium. Contrary to these expectations, we report that organismal performance traits had the highest heritabilities in a natural population of garter snakes.