Intensity of light diffraction from striated muscle as a function of incident angle.
Intensity of light diffraction from striated muscle as a function of incident angle.
复制标题
横纹肌的光衍射强度与入射角的函数关系。
DOI：
10.1016/s0006-3495(81)84764-9
复制
发表时间：
1981
影响因子：
3.4
通讯作者：
Yeh,Y
中科院分区：
文献类型：
--
作者：
Baskin,RJ;Lieber,RL;Oba,T;Yeh,Y
在最近发展起来的单横纹肌纤维光衍射理论中，我们只考虑了正常入射光束的情况。本研究既是对前人工作的实验和理论扩展，也是对任意入射角的扩展。在不同的肌节长度下，获得了50度范围内的角度扫描轮廓(+25度到-25度)。左、右一阶扫描峰间距是肌节长度(分离角=2θB)的函数，理论与实验符合较好。我们的理论分析进一步表明，具有单一公共偏斜角的肌原纤维群可以产生包含多个峰的角度扫描轮廓。因此，没有必要将每个峰值与不同的偏态总体相关联。最后，我们发现对称角，S，也随肌节长度而变化，但不是有规律的。它在给定肌节长度处的值是给定纤维的特定区域的函数，并且代表所有被照射的肌原纤维群体的平均偏斜角。衍射级线的强度被认为主要是两种干涉现象的结果。第一种是体栅现象，它是由光纤的周期性A-I带结构引起的(Z带和H带也有一定的贡献)。第二种是在满足入射角和斜角的正确关系的情况下，从斜面反射布拉格反射。这可能导致左和右一阶线之间的强度不对称。
In a recently developed theory of light diffraction by single striated muscle fibers, we considered only the case of normal beam incidence. The present investigation represents both an experimental and theoretical extension of the previous work to arbitrary incident angle. Angle scan profiles over a 50 degrees range of incident angle (+25 degrees to -25 degrees) were obtained at different sarcomere lengths. Left and right first-order scan peak separations were found to be a function of sarcomere length (separation angle=2 theta B), and good agreement was found between theory and experiment. Our theoretical analysis further showed that a myofibrillar population with a single common skew angle can yield an angle scan profile containing many peaks. Thus, it is not necessary to associate each peak with a different skew population. Finally, we have found that symmetry angle, theta s, also varies with sarcomere length, but not in a regular manner. Its value at a given sarcomere length is a function of a particular region of a given fiber and represents the average skew angle of all the myofibril populations illuminated. The intensity of a diffraction order line is considered to be principally the resultant of two interference phenomena. The first is a volume-grating phenomenon which results from the periodic A-I band structure of the fiber (with some contribution from Z bands and H zones). The second is Bragg reflection from skew planes, if the correct relation between incident angle and skew angle is met. This may result in intensity asymmetry between the left and right first order lines.