The parallel-plate flow chamber (PPFC) with rectangular shape, of which the height is far smaller than its own length and width, is one of the main apparatus for in vitro studies of the mechanical behavior of the cells. Considering that the Reynolds numbers of flows in the usually used PPFCs are small, a perturbation solution of laminar pulsatile Casson fluid in the PPFC is presented using Reynolds number as perturbation parameter. Furthermore, the velocities and shear stresses in the PPFC are given. The numerical results demonstrate that under the same pressure gradient the shear stresses are almost identical between Casson fluid and Newtonian fluid, whereas under the same flux the shear stresses are obviously different between Casson fluid and Newtonian fluid. The results in this paper provide a theoretical way to determine the shear stresses in the parallel-plate flow chamber under pulsatile Casson fluid.
Algorithms ; In Vitro Techniques ; Models, Cardiovascular ; Pulsatile Flow ; Stress, Mechanical

This study aimed to identify Inulae Herba, Inulae Flos and their closely related species using the ITS2 bar-code, and secure the quality and clinical curative effect of these medicinal materials. DNA was extracted from Inula linariifolia, I. japonica, I. britanica, which are the original species of Inulae Herba and Inulae Flos, together with their closely related species. The ITS2 sequence was amplified by PCR and sequenced bidirectionally. Sequence assembly and generation of consensus sequence were conducted by the CodonCode Aligner. The genetic distances were comput-ed using MEGA 5.0 in accordance with the Kimura-2-parameter (K2P) model, and the phylogenetic tree constructed by the neighbor-joining (NJ) method. The results showed that the ITS2 sequences of the various species have stable variable sites. The intraspecific genetic distances among Inulae Herba and Inulae Flos were obviously lower than the interspecific genetic distance among the above two medicinal materials and its adulterants. The NJ tree based on ITS2 sequences can clearly differ from Inulae Herba, Inulae Flos and their closely related species. It is concluded that ITS2 sequence can be used as DNA barcode to identify Inulae Herba, Inulae Flos and their closely related species.