1,371 research outputs found
Supercell Altermagnets
Altermagnets are compensated magnets with unconvetional , and -wave
spin-channel order in reciprocal space. So far the search for new altermagnetic
candidates has been focused on materials in which the magnetic unit cell is
identical to the non-magnetic one, i.e. magnetic structures with zero
propagation vector. Here, we substantially broaden the family of altermagnetic
candidates by predicting supercell altermagnets. Their magnetic unit cell is
constructed by enlarging the paramagnetic primitive unit cell, resulting in a
non-zero propagation vector for the magnetic structure. This connection of the
magnetic configuration to the ordering of sublattices gives an extra degree of
freedom to supercell altermagnets, which can allow for the control over the
order parameter spatial orientation. We identify realistic candidates MnSe
with a -wave order, and RbCoBr, CsCoCr, and BaMnO with -wave
order. We demonstrate the reorientation of the order parameter in MnSe,
which has two different magnetic configurations, whose energy difference is
only 5 meV, opening the possibility of controlling the orientation of the
altermagnetic order parameter by external perturbations.Comment: 10 pages, 4 figure
Synthesis and Anxiolytic Activity of some novel benzotriazole derivatives
1,2,3-Benzotriazole (BTA) is a heterocyclic compound with three nitrogen atoms. It is a polar and colourless compound which can be used for its great versatility. The enormous investigations on derivatives of benzotriazole reveal wide applicability for tagging and delivering a number of heterocyclic nuclei with this molecule. In the present work synthesis of several derivatives of 2-(substituted)-5-[(N-benzotriazolomethyl)-1,3, 4-thiadiazolyl]- imidazole-2-thione has been synthesized and are evaluated for their anxiolytic activity. The antianxiety activities of the synthesized derivatives were evaluated using EPM test and Bright and dark box test experimental models of anxiety. All results were expressed as mean± standard error mean (SEM) and analysed by one-way ANOVA. Post-hoc comparisons were performed by applying Dunnet’s test. P <0.05 was considered statistically significant.
Keywords: Benzotriazole; Thiadiazole; Thiazolidinone; Anxiolytic Activity; Anxiety; Elevated Plus Maize; Bright and Dark Arena
Local intra-uterine Ang-(1-7) infusion attenuates PGE2 and 6-keto PGF1α in decidualized uterus of pseudopregnant rats
Background: Cyclooxygenase (COX)-derived prostanoids (PGE2, PGI2) are important contributors to the process of decidualization. Previous studies showed the presence of Ang-(1-7) in the primary and secondary decidualized zones of the implantation site at early pregnancy. Decreased concentrations of Ang-(1-7) were found in the decidualized uterus compared to the non-decidualized uterus of pseudopregnant rats, suggesting that low levels of Ang-(1-7) are required for successful decidualization at early pregnancy.
Methods: To understand the role of Ang-(1-7) in prostaglandin production in a decidualized uterus, induced by a bolus injection of sesame oil, Ang-(1-7) (24 μg/kg/h) or vehicle was then infused directly into the decidualized uterine horn using an osmotic minipump. The right horns were not injected or infused and served as nondecidualized uterine horns in both groups of animals.
Results: Decidualization increased PGE2 concentration in the uterus (0.53±0.05 vs. 12.0±3.2 pmol/mg protein, p\u3c0.001, non-decidualized vs. decidualized horns); Ang-(1-7) infusion attenuated the increase of PGE2 (12.0± 3.2 vs. 5.1±1.3 pmol/mg protein, p\u3c0.01 control vs. Ang-(1-7) treated decidualized horns). The stable metabolite of PGI2 (6-keto PGF1α) was increased with decidualization (0.79±0.17 vs. 3.5±0.82 pmol/mg protein, p\u3c0.001, non-decidualized vs. decidualized horns). Ang-(1-7) infusion attenuated the increase in 6keto PGF1α in the decidualized horn (3.5±0.82 vs 1.8±0.37 pmol/mg protein, p\u3c0.05 control vs. Ang-(1-7) treated decidualized horns). The circulating levels of 6-keto-PGF1a and TXB2 were decreased by Ang-(1-7) infusion, while no difference was observed in circulating PGE2. Although the global assessment of cleaved caspase 3 immunostaining, a marker of apoptosis, was unchanged within the Ang-(1-7) decidualized horn, there were localized decreases in cleaved caspase 3 staining in the luminal region in the decidualized uterus of Ang-(1-7)-treated rats.
Conclusions: These studies show that increased local uterine Ang-(1-7) alters the uterine prostaglandin environment, possibly leading to disruptions of early events of decidualization
Fast high fidelity quantum non-demolition qubit readout via a non-perturbative cross-Kerr coupling
Qubit readout is an indispensable element of any quantum information
processor. In this work, we experimentally demonstrate a non-perturbative
cross-Kerr coupling between a transmon and a polariton mode which enables an
improved quantum non-demolition (QND) readout for superconducting qubits. The
new mechanism uses the same experimental techniques as the standard QND qubit
readout in the dispersive approximation, but due to its non-perturbative
nature, it maximizes the speed, the single-shot fidelity and the QND properties
of the readout. In addition, it minimizes the effect of unwanted decay channels
such as the Purcell effect. We observed a single-shot readout fidelity of 97.4%
for short 50 ns pulses, and we quantified a QND-ness of 99% for long
measurement pulses with repeated single-shot readouts
Strain control of band topology and surface states in antiferromagnetic EuCdAs
Topological semimetal antiferromagnets provide a rich source of exotic
topological states which can be controlled by manipulating the orientation of
the N\'eel vector, or by modulating the lattice parameters through strain. We
investigate via density functional theory calculations, the
effects of shear strain on the bulk and surface states n two antiferromagnetic
EuCdAs phases with out-of-plane and in-plane spin configurations. When
magnetic moments are along the -axis, a longitudinal or
diagonal shear strain can tune the Dirac semimetal phase to an axion insulator
phase, characterized by the parity-based invariant . For an
in-plane magnetic order, the axion insulator phase remains robust under all
shear strains. We further find that for both magnetic orders, the bulk gap
increases and a surface gap opens on the (001) surface up to 16 meV. Because of
a nonzero index and gapped states on the (001) surface, hinge modes
are expected to happen on the side surface states between those gapped surface
states. This result can provide a valuable insight in the realization of the
long-sought axion states.Comment: 5 pages, 4 figure
Using Gravitational Lensing to study HI clouds at high redshift
We investigate the possibility of detecting HI emission from gravitationally
lensed HI clouds (akin to damped Lyman- clouds) at high redshift by
carrying out deep radio observations in the fields of known cluster lenses.
Such observations will be possible with present radio telescopes only if the
lens substantially magnifies the flux of the HI emission. While at present this
holds the only possibility of detecting the HI emission from such clouds, it
has the disadvantage of being restricted to clouds that lie very close to the
caustics of the lens. We find that observations at a detection threshold of 50
micro Jy at 320 MHz (possible with the GMRT) have a greater than 20%
probability of detecting an HI cloud in the field of a cluster, provided the
clouds have HI masses in the range 5 X 10^8 M_{\odot} < M_{HI} < 2.5 X 10^{10}
M_{\odot}. The probability of detecting a cloud increases if they have larger
HI masses, except in the cases where the number of HI clouds in the cluster
field becomes very small. The probability of a detection at 610 MHz and 233 MHz
is comparable to that at 320 MHz, though a definitive statement is difficult
owing to uncertainties in the HI content at the redshifts corresponding to
these frequencies. Observations at a detection threshold of 2 micro Jy
(possible in the future with the SKA) are expected to detect a few HI clouds in
the field of every cluster provided the clouds have HI masses in the range 2 X
10^7 M_{\odot} < M_{HI} < 10^9 M_{\odot}. Even if such observations do not
result in the detection of HI clouds, they will be able to put useful
constraints on the HI content of the clouds.Comment: 21 pages, 7 figures, minor changes in figures, accepted for
publication in Ap
Spontaneous emission enhancement of a single molecule by a double-sphere nanoantenna across an interface
We report on two orders of magnitude reduction in the fluorescence lifetime
when a single molecule placed in a thin film is surrounded by two gold
nanospheres across the film interface. By attaching one of the gold particles
to the end of a glass fiber tip, we could control the modification of the
molecular fluorescence at will. We find a good agreement between our
experimental data and the outcome of numerical calculations
- …