688 research outputs found
TetraÂaquaÂbisÂ[3-(pyridin-4-yl)benzoato-κN]cobalt(II)
In the title compound, [Co(C12H8NO2)2(H2O)4], the Co atom lies on a twofold rotation axis and has an N2O4 octaÂhedral coordination environment formed by four O atoms of water molÂecules in the equatorial plane and two apical N atoms of pyridine groups. An intricate three-dimensional supraÂmolecular network is formed by multiple O—H⋯O hydrogen bonds between the coordinated water molÂecules and the uncoordinated carboxylÂate groups
Gap Anisotropy in Iron-Based Superconductors: A Point-Contact Andreev Reflection Study of BaFeNiAs Single Crystals
We report a systematic investigation on c-axis point-contact Andreev
reflection (PCAR) in BaFeNiAs superconducting single crystals
from underdoped to overdoped regions (0.075 ). At optimal
doping () the PCAR spectrum feature the structures of two
superconducting gap and electron-boson coupling mode. In the scenario,
quantitative analysis using a generalized Blonder-Tinkham-Klapwijk (BTK)
formalism with two gaps: one isotropic and another angle dependent, suggest a
nodeless state in strong-coupling limit with gap minima on the Fermi surfaces.
Upon crossing above the optimal doping (), the PCAR spectrum show an
in-gap sharp narrow peak at low bias, in contrast to the case of underdoped
samples (), signaling the onset of deepened gap minima or nodes in the
superconducting gap. This result provides evidence of the modulation of the gap
amplitude with doping concentration, consistent with the calculations for the
orbital dependent pair interaction mediated by the antiferromagnetic spin
fluctuations.Comment: 5 pages, 4 figure
Integral equation method for the electromagnetic wave propagation in stratified anisotropic dielectric-magnetic materials
We investigate the propagation of electromagnetic waves in stratified
anisotropic dielectric-magnetic materials using the integral equation method
(IEM). Based on the superposition principle, we use Hertz vector formulations
of radiated fields to study the interaction of wave with matter. We derive in a
new way the dispersion relation, Snell's law and reflection/transmission
coefficients by self-consistent analyses. Moreover, we find two new forms of
the generalized extinction theorem. Applying the IEM, we investigate the wave
propagation through a slab and disclose the underlying physics which are
further verified by numerical simulations. The results lead to a unified
framework of the IEM for the propagation of wave incident either from a medium
or vacuum in stratified dielectric-magnetic materials.Comment: 14pages, 3figure
Interleukin-22 ameliorates liver fibrosis through miR-200a/beta-catenin
IL-22 ameliorates liver fibrosis by inhibiting hepatic stellate cells (HSC), and loss of miR-200a is associated with the development of liver fibrosis. The study aimed to investigate the interplay between IL-22 and miR-200a in regulating liver fibrosis in vivo and in vitro. We observed that IL-22 significantly reduced the proliferation of HSC and increased the expression of p-STAT3. β-catenin was identified as a target gene of miR-200a by luciferase reporter assay, and upregulation of miR-200a significantly attenuated the proliferation of HSC and reduced β-catenin expression. IL-22 treatment increased expression of miR-200a and decreased expression of β-catenin in HSC. The expression of p-STAT3 and miR-200a was elevated while β-catenin was decreased in fibrotic rat liver after IL-22 treatment. Expression levels of β-catenin and p-STAT3 were inversely correlated in fibrotic rat liver and HSC. Upregulation of β-catenin suppressed expression of p-STAT3 in HSC. We concluded that IL-22 inhibits HSC activation and ameliorates liver fibrosis through enhancing expression of miR-200a and reducing expression of β-catenin, suggesting there may be a crosstalk between IL-22/STAT3 and β-catenin pathway
Anisotropic behaviour of human gallbladder walls
Inverse estimation of biomechanical parameters of soft tissues from non-invasive measurements has clinical significance in patient-specific modelling and disease diagnosis. In this paper, we propose a fully nonlinear approach to estimate the mechanical properties of the human gallbladder wall muscles from in vivo ultrasound images. The iteration method consists of a forward approach, in which the constitutive equation is based on a modified Hozapfel–Gasser–Ogden law initially developed for arteries. Five constitutive parameters describing the two orthogonal families of fibres and the matrix material are determined by comparing the computed displacements with medical images. The optimisation process is carried out using the MATLAB toolbox, a Python code, and the ABAQUS solver. The proposed method is validated with published artery data and subsequently applied to ten human gallbladder samples. Results show that the human gallbladder wall is anisotropic during the passive refilling phase, and that the peak stress is 1.6 times greater than that calculated using linear mechanics. This discrepancy arises because the wall thickness reduces by 1.6 times during the deformation, which is not predicted by conventional linear elasticity. If the change of wall thickness is accounted for, then the linear model can used to predict the gallbladder stress and its correlation with pain. This work provides further understanding of the nonlinear characteristics of human gallbladder
- …