Acute inflammation is an indispensable host response to foreign challenges or tissue injury. In healthy conditions, inflammatory processes are self-limiting and self-resolving, suggesting the ...existence of endogenous mechanisms for the control of inflammation and resolution. A comprehensive understanding of the cellular and molecular events of a well-orchestrated inflammatory response is required, and recent studies have uncovered the roles of endogenous lipid mediators derived from polyunsaturated fatty acids (i.e. lipoxins, resolvins, protectins) in controlling the resolution of inflammation. This review presents recent advances in understanding the formation and action of these mediators, especially focusing on the LC-MS/MS-based lipidomics approach and the emerging roles of eosinophils and eosinophil-derived lipid mediators in controlling acute inflammation and resolution.
Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and ...for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.
The topology of pure Bi is controversial because of its very small (∼10 meV) band gap. Here we perform high-resolution angle-resolved photoelectron spectroscopy measurements systematically on 14-202 ...bilayer Bi films. Using high-quality films, we succeed in observing quantized bulk bands with energy separations down to ∼10 meV. Detailed analyses on the phase shift of the confined wave functions precisely determine the surface and bulk electronic structures, which unambiguously show nontrivial topology. The present results not only prove the fundamental property of Bi but also introduce a capability of the quantum-confinement approach.
The three-dimensional topological semimetals represent a new quantum state of matter. Distinct from the surface state in the topological insulators that exhibits linear dispersion in two-dimensional ...momentum plane, the three-dimensional semimetals host bulk band dispersions linearly along all directions. In addition to the gapless points in the bulk, the three-dimensional Weyl/Dirac semimetals are also characterized by "topologically protected" surface state with Fermi arcs on their surface. While Cd3As2 is proposed to be a viable candidate of a Dirac semimetal, more investigations are necessary to pin down its nature. In particular, the topological surface state, the hallmark of the three-dimensional semimetal, has not been observed in Cd3As2. Here we report the electronic structure of Cd3As2 investigated by angle-resolved photoemission measurements on the (112) crystal surface and detailed band structure calculations. The measured Fermi surface and band structure show a good agreement with the band structure calculations with two bulk Dirac-like bands approaching the Fermi level and forming Dirac points near the Brillouin zone center. Moreover, the topological surface state with a linear dispersion approaching the Fermi level is identified for the first time. These results provide experimental indications on the nature of topologically non-trivial three-dimensional Dirac cones in Cd3As2.
In the hole-doped cuprates, a small number of carriers suppresses antiferromagnetism and induces superconductivity. In the electron-doped cuprates, on the other hand, superconductivity appears only ...in a narrow window of high-doped Ce concentration after reduction annealing, and strong antiferromagnetic correlation persists in the superconducting phase. Recently, Pr(1.3-x)La0.7Ce(x)CuO4 (PLCCO) bulk single crystals annealed by a protect annealing method showed a high critical temperature of around 27 K for small Ce content down to 0.05. Here, by angle-resolved photoemission spectroscopy measurements of PLCCO crystals, we observed a sharp quasi-particle peak on the entire Fermi surface without signature of an antiferromagnetic pseudogap unlike all the previous work, indicating a dramatic reduction of antiferromagnetic correlation length and/or of magnetic moments. The superconducting state was found to extend over a wide electron concentration range. The present results fundamentally challenge the long-standing picture on the electronic structure in the electron-doped regime.
•Fe-doped nanostructured WO3 films were synthesized using DC sputtering at RT.•The number of film defects was found to increase with increasing Fe concentrations.•The optical bandgap of the film ...(3.30eV) decreases to 3.15eV after doped with 2.6at% Fe.•The gas sensing of the 2.6at% Fe film to 3–12ppm NO2 at 150°C was significant.•The decrease in the material's band gap and an increase in defects enhanced sensing at lower temperature.
Fe-doped tungsten oxide thin films with different concentrations (0–2.6at%) were synthesized on glass and alumina substrates at room temperature using DC reactive sputtering and subsequently annealed at 300°C for 1h in air. The alumina substrate has pre-printed interdigitated Pt-electrodes for gas sensing measurements. The effects of Fe-doping on the film structure and morphology, electronic and optical properties for gas sensing were investigated. The grain size of the different films on the alumina and Pt regions of the substrate vary only slightly between 43 and 57nm with median size of about 50nm. Raman spectra showed that the integrated intensity of WO to OWO bands increases with increasing Fe concentrations and this indicated an increase in the number of defects. From XPS the different concentrations of the Fe-doped films were 0.03at%, 1.33at% and 2.6at%. All the films deposited on glass substrate have shown similar visible transmittance (about 70%) but the optical band gap of the pure film decreased form 3.30eV to 3.15eV after doping with 2.6at% Fe. The Fe-doped WO3 film with the highest Fe concentration (2.6at% Fe) has shown an enhanced gas sensing properties to NO2 at relatively lower operating temperature (150°C) and this can be attributed to the decrease in the optical band gap and an increase in the number of defects compared to the pure WO3 film.
Pseudomonas aeruginosa lung infection is a main cause of disability and mortality worldwide. Acute inflammation and its timely resolution are crucial for ensuring bacterial clearance and limiting ...tissue damage. Here, we investigated protective actions of resolvin (Rv) D1 in lung infection induced by the RP73 clinical strain of P. aeruginosa. RvD1 significantly diminished bacterial growth and neutrophil infiltration during acute pneumonia caused by RP73. Inoculum of RP73, immobilized in agar beads, resulted in persistent lung infection up to 21 days, leading to a non resolving inflammation reminiscent of human pathology. RvD1 significantly reduced bacterial titer, leukocyte infiltration, and lung tissue damage. In murine lung macrophages sorted during P. aeruginosa chronic infection, RvD1 regulated the expression of Toll-like receptors, downstream genes, and microRNA (miR)-21 and 155, resulting in reduced inflammatory signaling. In vitro, RvD1 enhanced phagocytosis of P. aeruginosa by neutrophils and macrophages, recapitulating its in vivo actions. These results unveil protective functions and mechanisms of action of RvD1 in acute and chronic P. aeruginosa pneumonia, providing evidence for its potent pro-resolution and tissue protective properties on airway mucosal tissue during infection.
III-nitride quantum dots are proving to be promising for application to single photon emitting devices. Research around the globe is revealing several interesting properties of these emitters, ...including a wide range of emission wavelengths, high temperature operation, and deterministic polarization of the emitted photons. Here a review is given on the single photon emission properties of such III-nitride quantum dots.
We have developed a state-of-the-art apparatus for laser-based spin- and angle-resolved photoemission spectroscopy with micrometer spatial resolution (µ-SARPES). This equipment is realized by the ...combination of a high-resolution photoelectron spectrometer, a 6 eV laser with high photon flux that is focused down to a few micrometers, a high-precision sample stage control system, and a double very-low-energy-electron-diffraction spin detector. The setup achieves an energy resolution of 1.5 (5.5) meV without (with) the spin detection mode, compatible with a spatial resolution better than 10 µm. This enables us to probe both spatially-resolved electronic structures and vector information of spin polarization in three dimensions. The performance of µ-SARPES apparatus is demonstrated by presenting ARPES and SARPES results from topological insulators and Au photolithography patterns on a Si (001) substrate.
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