Background: Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition. Methods: Initial radiation-induced DNA damage (ratio of Tail DNA/Head DN...

the present paper compares full kinetics mechanisms in numerical modelling of porous radiant burners (prb), with their reduced forms. the two most frequently used mechanisms of methane combustion (gri3.0 and miller) were selected and their effects were examined on temperature, species concentration, burning speed, and pollutant emission. while the findings of numerical simulation of prb show fi...

abstract three separate greenhouse experiments were conducted in the greenhouse facilities of the iranian plant protection research institute, tehran, to study the efficacy of some accase inhibiting herbicides for control of resistant based on mechanism, resistance based on enhanced metabolism and susceptible wild oat biotypes. in each experiment, biotypes were treated separately by 17 herbicid...

Single and multiple pulse laser damage studies are performed in Suprasil silica and BK-7 borosilicate glasses. Experiments are made in the bulk of materials at 1.064microm with nanosecond pulses, using an accurate and reliable measurement system. By means of a statistical study on laser damage probabilities, we demonstrate that the same nano-precursors could be involved in the multiple shot and...

The damage threshold and damage mechanism of extreme-ultraviolet Sc/Si multilayer mirror coatings are investigated with focused nanosecond pulses at 46.9-nm radiation from a compact capillary-discharge laser. Damage threshold fluences of approximately 0.08 J/cm2 are measured for coatings deposited on both borosilicate glass and Si substrates. The use of scanning and transmission electron micros...

DNA repair is an important activity for organisms to avoid various deleterious effects of DNA damage. Because it is tremendous work for cells to search the entire genome for a small number of lesions, there must be a special molecular mechanism for efficient damage recognition, which has not yet been understood completely. This may involve not only the evolution of damage recognition factors sp...

Ionization damage (radiolysis) and knock-on displacement are compared in terms of scattering cross section and stopping power, for thin organic specimens exposed to the electrons in a TEM. Based on stopping power, which includes secondary processes, radiolysis is found to be predominant for all incident energies (10-300 keV), even in materials containing hydrogen. For conducting inorganic speci...

Genotoxic stress causes proliferating cells to activate the DNA damage checkpoint, to assist DNA damage recovery by slowing cell cycle progression. Thus, to drive proliferation, cells must tolerate DNA damage and suppress the checkpoint response. However, the mechanism underlying this negative regulation of checkpoint activation is still elusive. We show that human Cyclin-Dependent-Kinases (CDK...

Excessive genome damage activates the apoptosis response. Protein kinase HIPK2 is a key regulator of DNA damage-induced apoptosis. Here, we deciphered the molecular mechanism of HIPK2 activation and show its relevance for DNA damage-induced apoptosis in cellulo and in vivo. HIPK2 autointeracts and site-specifically autophosphorylates upon DNA damage at Thr880/Ser882. Autophosphorylation regulat...

Chronic administration of acrylonitrile results in a dose-related increase in astrocytomas in rat brain, but the mechanism of acrylonitrile carcinogenicity is not fully understood. The potential of acrylonitrile or its metabolites to induce direct DNA damage as a mechanism for acrylonitrile carcinogenicity has been questioned, and recent studies indicate that the mechanism involves the inductio...