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.
Cell-mediated immunity is an immune response that does not involve antibodies but rather engages the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the issue of diverse cytokines in response to an antigen. Cellular immunity defends the body by: triggering antigen-specific cytotoxic T-lymphocytes that are able to induce apoptosis in the body cells displaying epitopes of the foreign antigen on their surface, such as cells with intracellular pathogens, virus-infected cells and cancer cells displaying tumor antigens; triggering macrophages and natural killer cells, enabling to destroy pathogens; and therefore stimulating cells to secrete a kind of cytokines that influence the function of other cells engaged in adaptive immune answers and innate immune answers. Cell-mediated immunity is administered primarily at microbes that survive in phagocytes and microbes that contaminate non-phagocytic units. It is also most effective in removing virus-infected cells, but also takes part in keeping defending against intracellular bacteria, protozoans, fungi and cancers. It also performances a foremost function in transplant rejection. The role of effector T cells in cell-mediated and humoral immune answers to agent pathogens. Cell-mediated immune answers engage the destruction of infected units by cytotoxic T units, or the destruction of intracellular pathogens by macrophages. The activation of naive T units in answer to antigen, and their subsequent expansion and differentiation, constitutes a prime immune response.
Last date updated on September, 2014