Experimental evidence for electron channeling in Fe /Au (100) superlattices

We present transport and structural data from epitaxial (100) and (111) Au/Fe superlattices grown by molecular beam epitaxy. From their analysis, we conclude that an electron channeling mechanism, due to strong specular reflection of the minority spin carrier at the Au/Fe interfaces, is responsible for the high conductivity in the (100) superlattices

Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay

Background: Hydrogen peroxide is a common reactive oxygen intermediate generated by variousforms of oxidative stress. Aims: The aim of this study was to investigate the DNA damage capacity ofH2O2 in HepG2 cells. Methods: Cells were treated with H2O2 at concentrations of 25 μM or 50 μM for5 min, 30 min, 40 min, 1 h or 24 h in parallel. The extent of DNA damage was assessed by the cometassay. Results: Compared to the control, DNA damage by 25 μM and 50 μM H2O2 increasedsignificantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Conclusions:Our Findings confirm that H2O2 is a typical DNA damage inducing agent and thus is a good modelsystem to study the effects of oxidative stress. DNA damage in HepG2 cells increased significantlywith H2O2 concentration and time of incubation but later decreased likely due to DNA repairmechanisms and antioxidant enzyme

On the process and outcomes of inquiry learning: Changing approaches to assessment

Inquiry learning is an educational approach that involves a process of exploration, asking questions and making discoveries in the search for new understandings. Researchers however are divided about the value of the approach. In the symposium, it is argued that one of the reasons for this controversy is the way that inquiry learning is assessed. Consequently, we aim to present papers which reflect on the challenge of assessing inquiry learning by describing the prevailing approaches to assessment and how technological and theoretical advancement is changing these approaches. The aim is not just to describe these approaches but reflect upon the opportunities that are created and difficulties that must be overcome as we pursue the goal of assessing the processes and outcomes of inquiry learnin