Mechanical factors and mechanism of keratoconus pathogenesis / 国际眼科杂志(Guoji Yanke Zazhi)

Keratoconus is a corneal ectatic disease characterized by progressive corneal thinning and protrusion. Its pathogenesis remains unclear. In vitro experiments have shown that mechanical stimulation may damage corneal stromal cells by increasing oxidative stress level and inflammatory factor concentration, resulting in a series of changes such as degradation of corneal extracellular matrix. Numerous clinical studies have confirmed that mechanical factors, including eye rubbing and eyeball compression caused by sleeping position, may play an important role in the process of keratoconus occurrence and development. They may affect the cornea by increasing the level of inflammatory factors in tear, causing changes in intraocular pressure, changing the biomechanical properties of the cornea, directly damaging corneal tissue by mechanical friction, and increasing the temperature of corneal epithelium. The main aim of this review was to describe the efforts of mechanical factors on corneal stromal cells, corneal tissue, and the possible role of mechanical factors in the pathogenesis of keratoconus, so as to provide a reference for the prevention and management of keratoconus.

Research Progress in Effects of Mechanical Factors on Angiogenesis of Vascular Endothelial Cells and the Mechanism / 医用生物力学

The angiogenic capacity of vascular endothelial cells is influenced by multiple mechanical factors. Mechanical factors guide the rearrangement of cytoskeleton, mediate intracellular signal transduction, affect cell migration, orientation and other behaviors, and then regulate their angiogenic capacity. However, different types of mechanical stimulation have different effects on their angiogenic capacity. This article summarizes and discusses the research work and progress of the influence of five mechanical factors （shear force, stretch stress, low-intensity pulsed ultrasound, microgravity, material properties） on vascular endothelial cell angiogenesis, which provides a basis and ideas for in-depth research of vascular biomechanics.

Prediction of Force on the Spine Using Three-Dimensional Mathematical Model / 대한척추외과학회지

Mechanical factors in the human body are considered to play a dominant role in low back pain problems. Various spinal structures, including muscles, act in unison to resist the external load. An estimation of the muscle forces in this structure requires a knowledge of the orientation, location and area of cross-section of the muscles to complete the formulation of a truly threedimensional mathematical model of the spine. The geometric parameters which are calculated were the line of action, the centroid and physiologic area of cross-section of each muscle as a function of the spinal level. This geometric data were obtained from CT scans of 11 subjects participating in this study.