Crofts C E, Trowbridge E A
Department of Medical Physics and Clinical Engineering, University of Sheffield, Royal Hallamshire Hospital, UK.
Biomaterials. 1989 May;10(4):230-4. doi: 10.1016/0142-9612(89)90098-7.
Forty squares of tissue, 40 mm X 40 mm, were harvested from bovine pericardium fixed in glutaraldehyde free of tension. Two parallel dumb-bell specimens were excised from each square. In 20 pairs of adjacent samples, two 1 mm cuts were introduced into one of the samples at the centre of the dumb-bell. The other 20 pairs were used as controls. There was no significant difference in tensile strength of the paired samples tested without cuts, but there was marked variation in the strength of the tissue in different squares. There was a significant positive correlation between the strength of the paired samples. Introduction of artificial tears produced a significant reduction in the strength of the tissue locally. However, a significant positive correlation between the sample with tears and the sample without tears was still maintained. Failure of the tissue under uniaxial load was observed dynamically by using a Panasonic video camera with zoom and magnification facilities illuminated by an oblique low-power light source placed behind the specimen. All samples, with or without tears, failed by rupture of a layer of tissue, laminate debonding and shear, followed by fibre slippage through the viscoelastic embedding matrix.
从无张力固定于戊二醛中的牛心包上切取40块40mm×40mm的组织块。从每块组织块上切下两个平行的哑铃形标本。在20对相邻样本中，在其中一个样本的哑铃形中央处切两个1mm的切口。另外20对样本用作对照。未切开的配对样本的拉伸强度无显著差异，但不同组织块的组织强度存在显著差异。配对样本的强度之间存在显著正相关。人工切口会使局部组织强度显著降低。然而，有切口样本与无切口样本之间仍保持显著正相关。使用配备变焦和放大功能的松下摄像机，通过置于标本后方的倾斜低功率光源照明，动态观察组织在单轴载荷下的破坏情况。所有样本，无论有无切口，均通过一层组织破裂、层间脱粘和剪切，随后纤维在粘弹性包埋基质中滑动而破坏。
