100 research outputs found
Moir\'e Fringes in Conductive Atomic Force Microscopy
Moir\'e physics plays an important role for the characterization of
functional materials and the engineering of physical properties in general,
ranging from strain-driven transport phenomena to superconductivity. Here, we
report the observation of moir\'e fringes in conductive atomic force microscopy
(cAFM) scans gained on the model ferroelectric Er(Mn,Ti)O. By performing a
systematic study of the impact of key experimental parameters on the emergent
moir\'e fringes, such as scan angle and pixel density, we demonstrate that the
observed fringes arise due to a superposition of the applied raster scanning
and sample-intrinsic properties, classifying the measured modulation in
conductance as a scanning moir\'e effect. Our findings are important for the
investigation of local transport phenomena in moir\'e engineered materials by
cAFM, providing a general guideline for distinguishing extrinsic from intrinsic
moir\'e effects. Furthermore, the experiments provide a possible pathway for
enhancing the sensitivity, pushing the resolution limit of local transport
measurements by probing conductance variations at the spatial resolution limit
via more long-ranged moir\'e patterns
Direct effects of doxorubicin on skeletal muscle contribute to fatigue
Chemotherapy-induced fatigue is a multidimensional symptom. Oxidative stress has been proposed as a working mechanism for anthracycline-induced cardiotoxicity. In this study, doxorubicin (DOX) was tested on skeletal muscle function. Doxorubicin induced impaired ex vivo skeletal muscle relaxation followed in time by contraction impediment, which could be explained by DOX-induced changes in Ca2+ responses of myotubes in vitro. The Ca2+ responses in skeletal muscle, however, could not be explained by oxidative stress
Scientific revolutions, specialization and the discovery of the structure of DNA: toward a new picture of the development of the sciences
N-hexanoyl-sphingomyelin potentiates in vitro doxorubicin cytotoxicity by enhancing its cellular influx
The Stringent Response and Cell Cycle Arrest in Escherichia coli
The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes upon arrest. Nucleoids of these cells are decondensed; in the absence of the ability to synthesize ppGpp, nucleoids become highly condensed, similar to that seen after treatment with the translational inhibitor chloramphenicol. After induction of the stringent response, while regions corresponding to the origins of replication segregate, the termini remain colocalized in wild-type cells. In contrast, cells arrested by rifampicin and cephalexin do not show colocalized termini, suggesting that the stringent response arrests chromosome segregation at a specific point. Release from starvation causes rapid nucleoid reorganization, chromosome segregation, and resumption of replication. Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact. We propose that DNA methylation and SeqA binding to non-origin loci is necessary to enforce a full stringent arrest, affecting both initiation of replication and chromosome segregation. This is the first indication that bacterial chromosome segregation, whose mechanism is not understood, is a step that may be regulated in response to environmental conditions
Varieties of living things: Life at the intersection of lineage and metabolism
publication-status: Publishedtypes: Articl
Application of discrete choice experiments to enhance stakeholder engagement as a strategy for advancing implementation: a systematic review
- …