Control of Karman Vortex Street behind a Thin Airfoil at Low Reynolds Number

To control the Karman vortex street formed behind a thin airfoil at a certain incidence, a control cylinder was placed at the suction side apart from the airfoil in the downstream region. Both smoke visualization and hot-wire measurements confirmed that the Karman vortex street was completely suppressed. The mechanism for suppression of the vortex street was examined with a hot-wire survey.

Replacement of the p16 gene in human ovarian cancer cells

Objective To study the inhibitory effects of retrovirus-mediated p16 gene on the human ovarian cancer cell line CAOV3.Methods The recombinant eukaryotic expression vector pDOR-p16 containing exogenous human wt-p16 cDNA and vector with neomycin resistance gene only were introduced into a CAOV3 cell line which does not express p16 endogenously by lipofectamine-mediated gene transfection. By using polymerase chain reaction amplification, mRNA in situ hybridization and immunocytochemistry, the clones obtained were tested for their efficiency of transfection and effects of vector expression. Their biologic behavior was observed further.Results Exogenous wt-p16 was transferred into CAOV3 cells successfully and permanent expression was obtained. The growth rate of the transfected CAOV3 cells in regular medium and soft agar was inhibited, and the tumorigenicity in nude mice showed that two of four mice failed to form tumors, and the others developed tumors 7 to 14 days later than mice of the contrast group. The percentage of phase G1 cells increased and that of phase S cells decreased. Under electron microscope, the ultrastructural changes of the cells revealed necrosis and growth retardation.Conclusions The p16 gene plays an important role in the generation and development of ovarian carcinoma. This study might provide experimental evidence for gene therapy in human ovarian cancer.