428 research outputs found
Novel aspects of sepsis pathophysiology: NETs, plasma glycoproteins, endotheliopathy and COVID-19
In 2016, sepsis was newly defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis remains one of the crucial medical problems to be solved worldwide. Although the world health organization has made sepsis a global health priority, there remain no specific and effective therapy for sepsis so far. Indeed, over the previous decades almost all attempts to develop novel drugs have failed. This may be partly ascribable to the multifactorial complexity of the septic cascade and the resultant difficulties of identifying drug targets. In addition, there might still be missing links among dysregulated host responses in vital organs. In this review article, recent advances in understanding of the complex pathophysiology of sepsis are summarized, with a focus on neutrophil extracellular traps (NETs), the significant role of NETs in thrombosis/embolism, and the functional roles of plasma proteins, histidine-rich glycoprotein (HRG) and inter-alpha-inhibitor proteins (IAIPs). The specific plasma proteins that are markedly decreased in the acute phase of sepsis may play important roles in the regulation of blood cells, vascular endothelial cells and coagulation. The accumulating evidence may provide us with insights into a novel aspect of the pathophysiology of sepsis and septic ARDS, including that in COVID-19
Magnetic and transport properties of the spin-state disordered oxide La0.8Sr0.2Co_{1-x}Rh_xO_{3-\delta}
We report measurements and analysis of magnetization, resistivity and
thermopower of polycrystalline samples of the perovskite-type Co/Rh oxide
LaSrCoRhO. This system constitutes a
solid solution for a full range of ,in which the crystal structure changes
from rhombohedral to orthorhombic symmetry with increasing Rh content . The
magnetization data reveal that the magnetic ground state immediately changes
upon Rh substitution from ferromagnetic to paramagnetic with increasing
near 0.25, which is close to the structural phase boundary. We find that one
substituted Rh ion diminishes the saturation moment by 9 , which implies
that one Rh ion makes a few magnetic Co ions nonmagnetic (the low
spin state), and causes disorder in the spin state and the highest occupied
orbital. In this disordered composition (), we find that
the thermopower is anomalously enhanced below 50 K. In particular, the
thermopower of =0.5 is larger by a factor of 10 than those of =0 and 1,
and the temperature coefficient reaches 4 V/K which is as large as
that of heavy-fermion materials such as CeRuSi.Comment: 8 pages, 6 figures, accepted to Phys. Rev.
Crystallographic and superconducting properties of the fully-gapped noncentrosymmetric 5d-electron superconductors CaMSi3 (M=Ir, Pt)
We report crystallographic, specific heat, transport, and magnetic properties
of the recently discovered noncentrosymmetric 5d-electron superconductors
CaIrSi3 (Tc = 3.6 K) and CaPtSi3 (Tc = 2.3 K). The specific heat suggests that
these superconductors are fully gapped. The upper critical fields are less than
1 T, consistent with limitation by conventional orbital depairing. High,
non-Pauli-limited {\mu}0 Hc2 values, often taken as a key signature of novel
noncentrosymmetric physics, are not observed in these materials because the
high carrier masses required to suppress orbital depairing and reveal the
violated Pauli limit are not present.Comment: 8 pages, 8 figure
Synthesis and photoemission study of as-grown superconducting MgB2 thin films
As-grown superconducting thin films of MgB2 were prepared by molecular beam
epitaxy (MBE), and studied by X-ray and ultraviolet photoelectron spectroscopy
(XPS and UPS). Only films prepared at temperatures between 150 and 320 deg.
showed superconductivity. A best TC onset of 36 K with a sharp transition width
of -1 K was obtained although the film crystallinity was poor. The in-situ
photoelectron spectra obtained on the surfaces of the MBE grown MgB2 films were
free from dirt peaks. XPS revealed that the binding energy of the Mg 2p levels
in MgB2 is close to that of metallic Mg, and the binding energy of B 1s is
close to that of transition-metal diborides. The valence UP spectra showed a
clear Fermi edge although the density of states (DOS) at EF is low and the
major components of the valence band are located between 5 and 11 eV.Comment: ISS 2001 proceedin
Pressure/temperature/substitution-induced melting of A-site charge disproportionation in Bi_(1-x)La_(x)NiO_3 (0 =< x =< 0.5)
Metal-insulator transitions strongly coupled with lattice were found in
Bi1-xLaxNiO3. Synchrotron X-ray powder diffraction revealed that pressure (P ~
3 GPa, T = 300 K), temperature (T ~ 340 K, x = 0.05), and La-substitution (x ~
0.075, T = 300 K) caused the similar structural change from a triclinic
(insulating) to an orthorhombic (metallic) symmetry, suggesting melting of the
A-site charge disproportionation. Comparing crystal structure and physical
properties with the other ANiO3 series, an electronic state of the metallic
phase can be described as [A3+Ld, Ni2+L1-d], where a ligand-hole L contributes
to a conductivity. We depicted a schematic P-T phase diagram of BiNiO3
including a critical point (3 GPa, 300 K) and an inhomogeneous region, which
implies universality of ligand-hole dynamics in ANiO3 (A = Bi, Pr, Nd,...).Comment: 24 pages, 8 figures, Phys. Rev. B in pres
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