In Vitro Fertilization (IVF) depends on upon the procurement of mature metaphase II oocytes, fertilization and persistence of the fertilized oocyte to the cleavage or blastocyst stage of embryonic development. At the inception of IVF, fruitful fertilization was entirely reliant upon the ability of ejaculated sperm to penetrate the outer boundaries of the oocyte, with the corona radiata (outer layer of cells surrounding the oocyte) and the zonal pellucida. The zona pellucida, which is the oocyte main boundary, permits or inhibits sperm from releasing its genetic material in to the cytoplasm (ooplasm) of the oocyte.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Last date updated on July, 2014