RESUMO
In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed.
RESUMO
PURPOSE: To show whether increased amounts of spermatozoa used in insemination of preovulatory oocytes in isolated teratozoospermia according to Kruger's strict criteria gives good fertilization rates. METHODS: This study was carried out from September 1993 to November 1994 for a total of 77 cycles, with sperm samples classified according to Kruger's strict classification. Group 1 (C; control) included 37 couples with normal sperm morphology (> 14% normal; SC). Group 2 (GP; good prognosis) included 18 couples (morphology, > or = 4 and < or = 14% normal) and group 3 (T; teratozoospermic) included 11 couples, with isolated teratozoospermia in the male partner (morphology, < 4% normal). RESULTS: No statistically significant difference was seen in the three groups regarding age, duration of infertility, aspirated follicles, oocytes collected, and embryos transferred. There is a statistically significantly difference (P < 0.001) in the number of spermatozoa used in insemination in group 3. CONCLUSIONS: In conclusion, a morphological classification using strict criteria in the assessment of sperm morphology is still very important, as increasing the sperm number of spermatozoa inseminated per oocyte may improve zona pellucida binding and give better IVF results.
