Estrogen is the major female sex hormone secreted primarily by the ovaries and in small amounts by the adrenal gland. It plays an important role in the onset of puberty, development of secondary sexual characteristics, such as breasts, and pubic and armpit hair. Estrogen also helps regulate the menstrual cycle and also controls breast changes during pregnancy.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 September, 2014
