2-methyl-1,4-naphthoquinone (menadione, MQ) was linked to synthetic oligonucleotides and exposed to near-UV light to generate base radical cations in DNA. This model system of electron transfer induced alkali-labile breaks at GG doublets, similar to anthraquinone and metallointercalators systems. In sharp contrast to other systems, the photolysis of MQ-DNA duplexes gave interstrand cross-links ...

The imbalance in to oxidants and antioxidants leads to the condition called oxidative stress. The oxidative stress is considered as one of the etiopathological factors for development and /or exacerbation of psoriasis. Therefore we undertook this study to determine serum levels of oxidants (Malondialdehyde MDA, Nitric oxide NO) and antioxidants (Total Antioxidant Status TAS, Superoxide Dismutas...

boiling of water for its purification has been recommended since 500 b. o. modern desinfecition methods involve specialized treatments for the purpose of destroying or inactivating pathogenic organisms . different factors .in flu - ensing the efficiency of desinfection are considered in this article physical and chemical methods of water desinfection are described briefly the use of chemical ox...

Abstract. Oxygenated organic molecules (OOMs) are dominated by the N-containing species in polluted urban environments. As OOMs, especially those with more than one nitrogen atom, prevail high m/z (mass-to-charge) range (m/z> 350 Th), unambiguous identification of OOMs is highly desirable for understanding their formation processes, precursors and influencing factors. To achieve this, we app...

Oxidants are highly unstable molecules that attack every chemical substance they come into contact. Oxidants modify the macromolecules both structurally and functionally. Body has defense mechanisms against oxidants in the form of both enzymatic and non-enzymatic antioxidants. Reactive oxygen species (ROS) are a group of oxidants formed during oxygen metabolism. ROS appears to be involved in th...

The distribution of Acacia dealbata Link (Fabaceae) in its non-native range is associated with disturbed areas. However, the possibility that it can penetrate the native forest during the invasion process cannot be ruled out. This statement is supported by the fact that this species has been experimentally established successfully under the canopy of native forest. Nonetheless, it is unknown wh...

Despite a wealth of studies exemplifying the utility of the 2-5 keV X-ray range in speciation and electronic structure elucidation, the exploitation of this energy regime for the study of photochemical processes has not been forthcoming. Herein, a new endstation set-up for in situ photochemical soft X-ray spectroscopy in the 2-5 keV energy region at the Stanford Synchrotron Radiation Lightsourc...

The photochemical release of inorganic nitrogen from dissolved organic matter is an important source of bio-available nitrogen (N) in N-limited aquatic ecosystems. We conducted photochemical experiments and used mathematical models based on pseudo-first-order reaction kinetics to quantify the photochemical transformations of individual N species and their seasonal effects on N cycling in a moun...

A comparative study of different sequences of two metal precursors [trimethylaluminum (TMA) and Tris(isopropylcyclopentadienyl) lanthanum (La(iPrCp)3)] for atomic layer deposition (ALD) lanthanum aluminum oxide (LaxAlyO) films is carried out. The percentage compositions of C and N impurity of LaxAlyO films were investigated using in situ X-ray photoelectron spectroscopy (XPS). The effects of di...

The activity of yeast invertase as a function of oxidation-reduction potential has been investigated using a large number of oxidants and reductants. The activity is constant over the range of E(h) from -270 to +600 mv., but above E(h) = +600 mv. there is a sharp decrease in activity reaching 0 at E(h) = +1,000 mv. The inhibiting action of strong oxidants is upon the enzyme rather than on the s...