death is something real which is fully accepted by human being, the definition of death is different among public and scientists such as philosophy experts and biologists. here we leave the philosophy content to themselves and look at the death from the biological point of view which may be some kind of philosophy as well. in biological science the death is well defined so it is the end of life...

Background: Several biological and medical benefits of Saffron, Crocus sativus (Iridaceae), have been demonstrated. However, mechanisms of actions for purified constituents are greatly unknown. Objective: To examine the effects of Safranal, a main constituent of Saffron stigma, on cell viability and cytokine profile of peripheral blood mononuclear cells (PBMC) were examined. Methods: Effect...

Development of potent new anti-Shigella agents for rapid and specific detection and treatment is of great importance. Aptamers, nucleic acid oligomers capable of specific binding to a wide range of non-nucleic acid targets, may be of value for this purpose. In the present study, we used a Systematic Evolution of Ligands by Exponential enrichment (SELEX) process to select DNA aptamers that b...

Background: To date, several imaging techniques to track stem cells are used such as positron emission tomography (PET), single photon emission computed tomography (SPECT), Bioluminescence imaging (BLI), fluorescence imaging, CT scan and magnetic resonance imaging (MRI). Although, overall sensitivity of MRI compared to SPECT and Bioluminescence techniques are lower, but due to high spatial reso...

background: as the use of mobile phones is increasing, public concern about the harmful effects of radiation emitted by these devices is also growing. in addition, protection questions and biological effects are among growing concerns which have remained largely unanswered. stem cells are useful models to assess the effects of radiofrequency electromagnetic fields (rf-emf) on other cell lines. ...

Background: The induction of bystander effect via ionizing radiation has been well proven. However, few studies have investigated the bystander effect following non-ionizing radiation, such as ultrasound waves. Here, the bystander effect after different sonication times on human melanoma cell line (A375), is evaluated by assessing cell viability and apoptosis. Materials and Methods: The cells w...

protection of biological systems against radiation damage is of paramount importance during accidental and unavoidable exposure to radiation. several physico-chemical and biological factors collectively contribute to the damage caused by radiation and are, therefore, targets for developing radioprotectors. chemicals capable of scavenging free radicals, relieving oxidative stress, promoting anti...

development of potent new anti-shigella agents for rapid and specific detection and treatment is of great importance. aptamers, nucleic acid oligomers capable of specific binding to a wide range of non-nucleic acid targets, may be of value for this purpose. in the present study, we used a systematic evolution of ligands by exponential enrichment (selex) process to select dna aptamers that b...

abstract regeneration is a biological phenomenon, which takes place via two main mechanisms: first, dedifferentiation of mature cells followed by their differentiation into functional new cells and second, activation of endogenous somatic stem cells for regeneration of damaged or lost tissues. one of the best examples of healing process in mammals is the regeneration of damaged pinna in rabbits...