The cuprates and iron-based high-temperature superconductors share many common features: layered strongly anisotropic crystal structure, strong electronic correlations, interplay between different types of electronic ordering, the intrinsic spatial inhomogeneity due to doping. The understanding of complex interplay between these factors is crucial for a directed search of new high-temperature superconductors. Here we show the appearance of inhomogeneous gossamer superconductivity in bulk FeSe compound at ambient pressure and at temperature 5 times higher than its zero-resistance T c . This discovery helps to understand numerous remarkable superconducting properties of FeSe. We also find and prove a general property: if inhomogeneous superconductivity in a anisotropic conductor first appears in the form of isolated superconducting islands, it reduces electric resistivity anisotropically with maximal effect along the least conducting axis. This gives a simple and very general tool to detect inhomogeneous superconductivity in anisotropic compounds, which is critically important to study the onset of high-temperature superconductivity.
Epigenetic mechanisms of gene regulation in context of cardiovascular diseases are of considerable interest. So far, our current knowledge of the DNA methylation profiles for atherosclerosis affected and healthy human vascular tissues is still limited. Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of the right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues. The DNA methylation differences observed in vascular tissues of patients with coronary heart disease can provide new insights into the mechanisms underlying the development of pathology and explanation for the difference in graft patency after coronary artery bypass grafting surgery.
In an earlier study (Emeline, A. V.; Ryabchuk, V. K.; Serpone, N. J.
Phys. Chem. B
1999, 103, 1316) we
reported the solution to the continuity equation in which we neglected electric field effects and obtained
expressions for the concentrations of the charge carriers at the surface (n
s), for the quantum yield (Φ) of a
photochemical surface redox reaction, together with an expression for the selectivity of the photocatalyst.
Various considerations led us to infer and predict wavelength-dependent phenomena (quantum yields and
selectivity), which were later confirmed by experimental results (Emeline, A. V.; Serpone, N. J. Phys. Chem.
B
2002, 106, 12221). In this article we revisit the continuity equation but include a subsurface electric field
(E) in the space charge region of the semiconductor (or dielectric) photocatalyst to assess the effect that the
electric field has on the activity and selectivity of the photocatalyst. The solution to the continuity equation
yields very complex expressions for n
s and for Φ. Nonetheless, several cases are considered which simplify
the expressions. Taking E = 0, the expression for the quantum yield transforms into the identical equation
obtained earlier. Some of the predictions from the expressions obtained herein also find experimental verification
from considerations, for example, of the quantum yields of photoadsorption of dioxygen and dihydrogen on
TiO2 particles. The agreement between the predicted spectral behavior of the ratio γ = [es]/[hs] against
wavelength with the spectral dependence of ΦO
2
/ΦH
2
is remarkable. Another no less significant conclusion
from the theoretical modeling results is that a mismatch between the experimental spectral dependence of the
quantum yield and the corresponding absorption band may be an indicator of the existence of a space charge
region in the solid photocatalyst.
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