287 research outputs found
(1E)-6-MethÂoxy-3,4-dihydroÂnaphthalen-1(2H)-one oxime
In the crystal structure of the title compound, C11H13NO2, the molÂecules are paired into centrosymmetric dimers via interÂmolecular O—H⋯N hydrogen bonds
Magnon-bandgap controllable artificial domain wall waveguide
In this paper, a magnon-bandgap controllable artificial domain wall waveguide
is proposed by means of micromagnetic simulation. By the investigation of the
propagation behavior and dispersion relationship of spin waves in artificial
domain wall waveguides, it is found that the nonreciprocal propagation of spin
waves in the artificial domain walls are mainly affected by the local effective
exchange field, and the magnon bandgap can be controlled by changing the
maximum value of the effective exchange field. In addition, it is observed that
the artificial domain wall waveguides are structurally more stable than the
natural domain wall waveguides under the same spin wave injection conditions,
and the magnon bandgap of the artificial domain wall waveguides can be adjusted
by its width and magnetic anisotropy parameters. The bandgap controllable
artificial domain wall scheme is beneficial to the miniaturization and
integration of magnon devices and can be applied to future magnonic technology
as a novel frequency filter
Aqueous extract of Sargentodoxa cuneata alleviates ulcerative colitis and its associated liver injuries in mice through the modulation of intestinal flora and related metabolites
BackgroundUlcerative colitis (UC) is a refractory disease worldwide. Liver injury can be found clinically with UC, and now, it is found that gut dysbiosis is an important mechanism in the pathogenesis of UC. Sargentodoxa cuneata has been used as a traditional Chinese medicine and is commonly used clinically for the treatment of UC. The main objective of this study was to investigate the intrinsic mechanisms of Sargentodoxa cuneata in the treatment of UC and its associated liver injuries from the perspective of intestinal flora and related metabolites.MethodsUltra-performance liquid chromatography-mass spectrometry was used to identify the components in the aqueous extract of Sargentodoxa cuneata (AESc). Mice with UC induced by dextran sulfate sodium were used to study the effects of AESc on UC and its associated liver injuries. Furthermore, 16S rRNA gene sequencing and analysis were performed on intestinal contents, and correlation analysis of intestinal flora with short-chain fatty acids (SCFAs) and organic acids was performed.ResultsA total of 114 compounds were identified in AESc. AESc improved disease activity index scores, liver index, and colon length in mice with UC and had a good protective effect on intestine and liver injuries. Moreover, the administration of AESc regulated gut microbiota dysbiosis and the levels of a few SCFAs and organic acids in mice with UC. In addition, the correlation analysis results showed that the Megamonas and Bifidobacterium were the key intestinal flora related to the levels of differential SCFAs and organic acids in mice with UC after AESc intervention.ConclusionAESc has a good protective effect on UC and UC related liver injuries. Modulation of the intestinal flora and its metabolites (SCFAs and a few organic acids) is an important pathway for AESc in the treatment of UC and also provides a rationale for the clinical use of Sargentodoxa cuneata in the treatment of UC
SO(1,1) dark energy model and the universe transition
We suggest a scalar model of dark energy with the SO(1,1) symmetry. The model
may be reformulated in terms of a real scalar field and the scale factor
so that the Lagrangian may be decomposed as that of the real quintessence
model plus the negative coupling energy term of to . The existence of
the coupling term leads to a wider range of and overcomes the
problem of negative kinetic energy in the phantom universe model. We propose a
power-law expansion model of univese with time-dependent power, which can
describe the phantom universe and the universe transition from ordinary
acceleration to super acceleration.Comment: 12 pages. submitted to CQ
Hybrid materials of pyrene substituted phthalocyanines with single-walled carbon nanotubes: structure and sensing properties
Hybrid materials of single walled carbon nanotubes (SWCNT) were obtained by their non-covalent functionalization with asymmetrically polyoxyethylene substituted phthalocyanines (MPc-py (M = Cu, Co, 2H)) bearing one pyrene group as a substituent. The attachment of MPc-py molecules onto the SWCNT surface have been confirmed using Raman spectroscopy, SEM, TEM and thermogravimetric analysis. The pyrene substituents were introduced to the phthalocyanine macrocycle in order to improve π–π interaction between the MPc-py and SWCNT. The effect of the central metal on the formation and sensor properties of the MPc-py within the hybrids has been verified. It has been shown that the electrical response of the hybrid films to ammonia vapor in the concentration range of 10–50 ppm changes in the following order CuPc-py > CoPc-py > H2Pc-py, which was found to be in good correlation with the amount of phthalocyanine molecules adsorbed onto the SWCNT walls, as estimated by thermogravimetric analysis (TGA)
Cosmology with Interaction between Phantom Dark Energy and Dark Matter and the Coincidence Problem
We study a cosmological model in which phantom dark energy is coupled to dark
matter by phenomenologically introducing a coupled term to the equations of
motion of dark energy and dark matter. This term is parameterized by a
dimensionless coupling function , Hubble parameter and the energy
density of dark matter, and it describes an energy flow between the dark energy
and dark matter. We discuss two cases: one is the case where the
equation-of-state of the dark energy is a constant; the other is
that the dimensionless coupling function is a constant. We investigate
the effect of the interaction on the evolution of the universe, the total
lifetime of the universe, and the ratio of the period when the universe is in
the coincidence state to its total lifetime. It turns out that the interaction
will produce significant deviation from the case without the interaction.Comment: Latex, 17 pages including 14 figures, minor change
Transient Receptor Potential V Channels Are Essential for Glucose Sensing by Aldolase and AMPK
Fructose-1,6-bisphosphate (FBP) aldolase links sensing of declining glucose availability to AMPK activation via the lysosomal pathway. However, how aldolase transmits lack of occupancy by FBP to AMPK activation remains unclear. Here, we show that FBP-unoccupied aldolase interacts with and inhibits endoplasmic reticulum (ER)-localized transient receptor potential channel subfamily V, inhibiting calcium release in low glucose. The decrease of calcium at contact sites between ER and lysosome renders the inhibited TRPV accessible to bind the lysosomal v-ATPase that then recruits AXIN:LKB1 to activate AMPK independently of AMP. Genetic depletion of TRPVs blocks glucose starvation-induced AMPK activation in cells and liver of mice, and in nematodes, indicative of physical requirement of TRPVs. Pharmacological inhibition of TRPVs activates AMPK and elevates NAD(+) levels in aged muscles, rejuvenating the animals' running capacity. Our study elucidates that TRPVs relay the FBP-free status of aldolase to the reconfiguration of v-ATPase, leading to AMPK activation in low glucose
Coupled dark energy: Towards a general description of the dynamics
In dark energy models of scalar-field coupled to a barotropic perfect fluid,
the existence of cosmological scaling solutions restricts the Lagrangian of the
field \vp to p=X g(Xe^{\lambda \vp}), where X=-g^{\mu\nu} \partial_\mu \vp
\partial_\nu \vp /2, is a constant and is an arbitrary function.
We derive general evolution equations in an autonomous form for this Lagrangian
and investigate the stability of fixed points for several different dark energy
models--(i) ordinary (phantom) field, (ii) dilatonic ghost condensate, and
(iii) (phantom) tachyon. We find the existence of scalar-field dominant fixed
points (\Omega_\vp=1) with an accelerated expansion in all models
irrespective of the presence of the coupling between dark energy and dark
matter. These fixed points are always classically stable for a phantom field,
implying that the universe is eventually dominated by the energy density of a
scalar field if phantom is responsible for dark energy. When the equation of
state w_\vp for the field \vp is larger than -1, we find that scaling
solutions are stable if the scalar-field dominant solution is unstable, and
vice versa. Therefore in this case the final attractor is either a scaling
solution with constant \Omega_\vp satisfying 0<\Omega_\vp<1 or a
scalar-field dominant solution with \Omega_\vp=1.Comment: 21 pages, 5 figures; minor clarifications added, typos corrected and
references updated; final version to appear in JCA
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