INTRODUCTION Some unexplained infertile couples may have fertilization failure; the in vitro fertilization (IVF) with high insemination concentration (HIC) and intracytoplasmic sperm injection (ICSI) were reported to give better fertilization rate when compared to standard IVF procedure. OBJECTIVE To compare the fertilization rate, abnormal fertilization rate, total fertilization failure rate...

Prevention of polyspermic fertilization in sea urchins (Jaffe, 1976, Nature (Lond.). 261:68-71) and the worm Urechis (Gould-Somero, Jaffe, and Holland, 1979, J. Cell Biol. 82:426-440) involves an electrically mediated fast block. The fertilizing sperm causes a positive shift in the egg's membrane potential; this fertilization potential prevents additional sperm entries. Since in Urechis the egg...

The eccentric shift of the sea-urchin egg within the fertilization membrane under an electric field was analysed by measuring the electrophoretic mobility of the isolated fertilization membrane and that of the egg deprived of the fertilization membrane. In addition, the migration speed of the egg proper was measured within the fertilization membrane under the conditions that: either (1) the mov...

Water and fertilizers affect the nitrogen (N) and phosphorus (P) acquisition and allocation among organs in dominant species in natural vegetation on the semiarid Loess Plateau. This study aimed to clarify the N and P accumulation and N:P ratio at organ and plant level of a local legume species mixed with a grass species under varying water and fertilizer supplies, and thus to fully understand ...

This study assessed the effects of common extenders and diluents on the spermatozoa of African catfish (Clarias gariepinus), with the intent of obtaining a semen preservation protocol that can serve as a means of making fingerlings available to fish farmers all year round. Semen samples (milt) were pooled from mature broodstock males and pre-extension qualities were evaluated. Egg yolk, tomato ...

background: determination of oocyte and embryo quality are one of the most important goals in ivf. anti-mullerian hormone (amh) is secreted by the ovarian granulosa cells into blood flow and follicular fluid. follicular fluid anti-mullerian hormone level is probably a marker of activity of granulose cells. objective: to evaluate whether high level of follicular fluid anti-mullerian hormone leve...

In the paper the basics and the software concept of a real time simulator for virtual surgery is presented. The simulator is aimed to be applicable in soft tissue surgery and has been tested in virtual laparoscopy. The general software concept is presented first. Then the modeling approach of soft tissues, such as liver, gall, milt etc., is decribed. The main challenge is to achieve a good phys...

The savings/investment process in capitalist economies is organized around financial intermediation, making them a central institution of economic growth. Financial intermediaries are firms that borrow from consumer/savers and lend to companies that need resources for investment. In contrast, in capital markets investors contract directly with firms, creating marketable securities. The prices o...

Background: Failed fertilization post ICSI has been mainly attributed to the sperm’s inability to induce oocyte activation. Phospholipase C Zeta (PLCζ) is considered to be a primary factor for the induction of oocyte activation. The aim of this study was to quantitatively assess the expression of PLCζ in globozoospermic or individuals with previous low or failed fertilization in comparison to f...

To investigate the mechanisms that account for the voltage dependence of fertilization and provide an electrical block to polyspermy, we studied cross-fertilizations between three species of amphibians having different degrees of voltage dependence. Anurans, such as the toad Bufo japonicus, as well as the primitive urodele Hynobius nebulosus, have voltage-dependent fertilization; other urodeles...