47 research outputs found
Ectoine can enhance structural changes in DNA in vitro
Strand breaks and conformational changes of DNA have consequences for the
physiological role of DNA. The natural protecting molecule ectoine is
beneficial to entire bacterial cells and biomolecules such as proteins by
mitigating detrimental effects of environmental stresses. It was postulated
that ectoine-like molecules bind to negatively charged spheres that mimic DNA
surfaces. We investigated the effect of ectoine on DNA and whether ectoine is
able to protect DNA from damages caused by ultraviolet radiation (UV-A). In
order to determine different isoforms of DNA, agarose gel electrophoresis and
atomic force microscopy experiments were carried out with plasmid pUC19 DNA.
Our quantitative results revealed that a prolonged incubation of DNA with
ectoine leads to an increase in transitions from supercoiled (undamaged) to
open circular (single-strand break) conformation at pH 6.6. The effect is pH
dependent and no significant changes were observed at physiological pH of 7.5.
After UV-A irradiation in ectoine solution, changes in DNA conformation were
even more pronounced and this effect was pH dependent. We hypothesize that
ectoine is attracted to the negatively charge surface of DNA at lower pH and
therefore fails to act as a stabilizing agent for DNA in our in vitro
experiments
Biogenic synthesis and spectroscopic characterization of silver nanoparticles using leaf extract of Indoneesiella echioides: in vitro assessment on antioxidant, antimicrobial and cytotoxicity potential
Interaction of Self-Assembled Monolayers of DNA with Electrons: HREELS and XPS Studies
Current Wildland Fire Patterns and Challenges in Europe: A Synthesis of National Perspectives
Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009–2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action “Fire and the Earth System: Science & Society” funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence
The nature of strongly adsorbed species in electrocatalytic oxidation of formaldehyde on palladium, platinum and rhodium electrodes in acidic media An in-situ IR study
Microarray technology for the study of DNA damage by low-energy electrons
The damage induced to a model DNA (dT immobilized on a gold surface
by the interaction of low-energy (1 eV) electrons was studied by means of
microarray technology. High quality single-stranded DNA arrays were
hybridized with a dye-marked complementary strand after irradiation with
electrons and the normalized fluorescence data were used to quantify the DNA
damage. The data clearly show the sensitivity of the method. A significant
loss of genetic information was already observed at dose as low as few
hundred of electrons per immobilized oligonucleotide. The results imply that
single stranded DNA and RNA are appreciably more sensitive to radiation and
the attack of secondary electrons during replication, transcription or
translation stages than the current radiation damage models envisage
J. Phys. Chem. B
Single-stranded DNA oligonucleotides (33-mers) containing different numbers of guanines (n = 1−4) were tethered to a gold surface and exposed to 1 eV electrons. The electrons induced DNA damage, which was analyzed with fluorescence and infrared spectroscopy methods. The damage was identified as strand breaks and found to correlate linearly with the number of guanines in the sequence. This sequence dependence indicates that the electron capture by the DNA bases plays an important role in the damage reaction mechanism