7,112 research outputs found
Nanometers-thick self-organized Fe stripes: bridging the gap between surfaces and magnetic materials
We have fabricated 5nm-high Fe(110) stripes by self-organized (SO) growth on
a slightly vicinal R(110)/Al2O3(11-20) surface, with R=Mo, W. Remanence,
coercivity and domain patterns were observed at room temperature (RT). This
contrasts with conventional SO epitaxial systems, that are superparamagnetic or
even non-magnetic at RT due to their flatness. Our process should help to
overcome superparamagnetism without compromise on the lateral size if SO
systems are ever to be used in applications
ADAR enzyme and miRNA story: A nucleotide that can make the difference
Adenosine deaminase acting on RNA (ADAR) enzymes convert adenosine (A) to inosine (I) in double-stranded (ds) RNAs. Since Inosine is read as Guanosine, the biological consequence of ADAR enzyme activity is an A/G conversion within RNA molecules. A-to-I editing events can occur on both coding and non-coding RNAs, including microRNAs (miRNAs), which are small regulatory RNAs of ~20-23 nucleotides that regulate several cell processes by annealing to target mRNAs and inhibiting their translation. Both miRNA precursors and mature miRNAs undergo A-to-I RNA editing, affecting the miRNA maturation process and activity. ADARs can also edit 3' UTR of mRNAs, further increasing the interplay between mRNA targets and miRNAs. In this review, we provide a general overview of the ADAR enzymes and their mechanisms of action as well as miRNA processing and function. We then review the more recent findings about the impact of ADAR-mediated activity on the miRNA pathway in terms of biogenesis, target recognition, and gene expression regulation
Temperature dependence of surface stress across an order-disorder transition: p(1x2)O/W(110)
Strain relaxations of a p(1x2) ordered oxygen layer on W(110) are measured as
a function of temperature across the disordering transition using low-energy
electron diffraction. The measured strains approach values of 0.027 in the
[1-10] and -0.053 in the [001] direction. On the basis of the measured strain
relaxations, we give quantitative information on temperature-dependent surface
stress using the results of ab initio calculations. From the surface formation
energy for different strains, determined by first-principles calculations, we
estimate that surface stress changes from -1.1 for the ordered phase to -0.2N/m
for the disordered one along [1-10], and from 5.1 to 3.4 N/m along [001].
Moreover, our observation that the strains scale inversely with domain size
confirms that the strain relaxation takes place at the domain boundaries.Comment: 8 pages, 5 figure
Path-tracking of a tractor-trailer vehicle along rectilinear and circular paths: A Lyapunov-based approach
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