The cell which can differentiate and produce different types of tissues is called stem cell. During the embryonic and early growth stages the stem can differentiate into many tissues and organs. The stem cell can replenish old and damaged tissue through regeneration. Stem cell are of different types they are embryonic stem cell and non-embryonic somatic stem cells.
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 June, 2014