IB-LBM simulation of the haemocyte dynamics in a stenotic capillary.

To study the behaviour of a haemocyte when crossing a stenotic capillary, the immersed boundary-lattice Boltzmann method was used to establish a quantitative analysis model. The haemocyte was assumed to be spherical and to have an elastic cell membrane, which can be driven by blood flow to adopt a highly deformable character. In the stenotic capillary, the spherical blood cell was stressed both by the flow and the wall dimension, and the cell shape was forced to be stretched to cross the stenosis. Our simulation investigated the haemocyte crossing process in detail. The velocity and pressure were anatomised to obtain information on how blood flows through a capillary and to estimate the degree of cell damage caused by excessive pressure. Quantitative velocity analysis results demonstrated that a large haemocyte crossing a small stenosis would have a noticeable effect on blood flow, while quantitative pressure distribution analysis results indicated that the crossing process would produce a special pressure distribution in the cell interior and to some extent a sudden change between the cell interior and the surrounding plasma.

Biomechanical research of different polypropylene meshes in breast ptosis correction / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the biomechanical properties of different polypropylene meshes, so as to select the proper mesh for breast ptosis correction as inner bra.</p><p><b>METHODS</b>Mini-pigs were used as animal model. Four different polypropylene meshes were implanted subcutaneously at abdomen. 90 d later, the specimens were taken out for biomechanical study.</p><p><b>RESULTS</b>The tensile strength, stress, relaxation and creep of the four meshes were different. The material and the knitting of the four meshes were different.</p><p><b>CONCLUSIONS</b>The biomechanical properties of relaxation and creep are important in maintaining the postoperative breast figure. Premilene Mesh LP is a new and light polypropylene mesh with mini-pores. Its biomechanical properties are superior to the others.</p>

Biomechanical properties of the costal cartilage and its significance in the timing of ear reconstruction / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the age-related change in biomechanical properties of the costal cartilage and its relevance to the timing of ear reconstruction with costal cartilage framework.</p><p><b>METHODS</b>The patients of 5 to 25 years old were divided into three groups according to their age. The biomechanical properties of costal cartilage harvested from these patients during ear reconstruction were tested, including stree-strain relationship, stress relaxation and creep, tensile strength. All the results were analyzed statistically.</p><p><b>RESULTS</b>The costal cartilage from children group had the best biomechanical properties, while the costal cartilage from the adolescent group had the worst. The difference had a statistically significance (P < 0.05).</p><p><b>CONCLUSIONS</b>The biomechanical properties of costal cartilage are age-related. So it is recommended that ear reconstruction with costal cartilage framework should be performed in childhood when the costal cartilage has the best biomechanical properties.</p>