PURPOSE Although DNA lesions are considered of prime importance for describing the post-irradiation cellular survival, they still remain rarely studied on both experimental and theoretical sides. Under these conditions, we here propose different theoretical models for predicting the single ionization and single capture total cross sections for DNA bases impacted by protons. MATERIAL AND METHO...

Phase variation of genes in bacteria enables phenotypic alteration to modulate interactions within a host as conditions change. To promote commensalism in animals and disease in humans, Campylobacter jejuni produces a flagellar organelle for motility. In addition to tight transcriptional regulation of flagellar genes, C. jejuni also controls flagellar biosynthesis by phase variation. In this st...

The author received his PhD in physics from the University of Chicago. His research interests lie in the areas of developmental biology and evolution. On February 28, 1953, in a pub in Cambridge, Francis Crick was telling everyone who cared to listen that he and James Watson had just discovered the secret of life. The April 25 issue of the journal Nature carried the same news in the form of the...

We studied the electroanalytical performances of chemically-modified graphenes (CMGs) containing different defect densities and amounts of oxygen-containing groups, namely graphite oxide (GPO), graphene oxide (GO), thermally reduced graphene oxide (TR-GO) and electrochemically reduced graphene oxide (ER-GO) by comparing the sensitivity, selectivity, linearity and repeatability towards the oxida...

Hydrated ionic liquids (ILs) have been identified as solvent media able to enhance the structural stability of deoxyribonucleic acid (DNA). In this work, we investigate molecular interaction between imidazolium-based ILs and DNA during its thermal unfolding pathway, by exploiting synchrotron-based UV Resonance Raman scattering (UVRR) experiments. This technique gives a selective focus on respon...

It has been shown (a) that the inhibition of Lactobacillus casei by high concentrations of 2,6-diaminopurine (2,6-DAP) in a folic acid-containing medium is reversible only by adenine, while in a thymine-containing medium adenine is more effective than other purines in restoring growth (l), (b) that 2,6-DAP is extensively utilized as a precursor of both polynucleotide adenine and polynucleotide ...

we have evaluated the nmr shielding tensors for a:t,g:c,a:u in watson-crick, and u-quartet. we have computed nmr shielding tensors at b31yp level by using 6-31g(d) basis set. we have compute anisotropy and asymmetry in a:t,g:c,a:u and u-quartet. the nmr shielding tensors were calculated using the giao method. the natural bonding orbital analysis (nbo) were performed. nbo calculation have been ...

Ionizing alpha radiation (He2+) is known to adversely affect human DNA, but the biochemical reasoning not clear yet. Relatedly, present computational study was conducted investigating effects of ionizing onto Watson-Crick type DNA base pairs (nucleotides) Adenine-Thymine (AT’) and Guanine-Cytosine (GC’). The long-range cation (He2+)−π interactions were modeled for this purpose. A hybrid DFT fun...

When the nonprotein chromophore of neocarzinostatin was allowed to react with either calf thymus DNA or poly(dA-dT) . poly(dA-dT) in the presence of 2-mercaptoethanol and the DNA was precipitated with ethanol, 5% of the fluorescence attributable to the naphthalene rings of the chromophore coprecipitated with the DNA. Most of this fluorescence remained attached to DNA through successive reprecip...

eral, localizing substances of adequate selectivity that can be labeled and used for radiotherapy have not been discovered. If such are found, it would be desirable that they carry a radioactive isotope which emits a very soft ray, such as iH3 or eC14. Even these emit beta-rays that traverse several cell diameters; however, the half penetration of the iH3 beta-ray is less than the radius of the...