The biology and t heories of aging.

Aging is a natural, time-dependent process characterized by irreversible changes in the molecules, cells, tissues, and organs. It occurs as a result of cumulative damage at different levels of the organization, in particular by damaging proteins and DNA. There is no single definition, nor a unique attitude about when and how age arises and what are its causes.

Impact of the toxicity of Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju on laboratory rats in vivo.

In vivo laboratory studies of toxicity were performed on Wistar rats using a methanol extract produced by the natural population of Cylindrospermopsis raciborskii (abundance of 2.13 × 10 trichomes mL) collected at Aleksandrovac Lake (Serbia). HPLC analysis showed that the extract contains 6.