5,275 research outputs found
Real-time evolution method and its application to 3 cluster system
A new theoretical method is proposed to describe the ground and excited
cluster states of atomic nuclei. The method utilizes the equation-of-motion of
the Gaussian wave packets to generate the basis wave functions having various
cluster configurations. The generated basis wave functions are superposed to
diagonalize the Hamiltonian. In other words, this method uses the real time as
the generator coordinate. The application to the system as a
benchmark shows that the new method works efficiently and yields the result
consistent with or better than the other cluster models. Brief discussion on
the structure of the excited and states is also made
Translating nano-Hertz gravitational wave background into primordial perturbations taking account of the cosmological QCD phase transition
The evidence of the nano-Hertz stochastic gravitational wave (GW) background
is reported by multiple pulsar timing array collaborations. While a prominent
candidate of the origin is astrophysical from supermassive black hole binaries,
alternative models involving GWs induced by primordial curvature perturbations
can explain the inferred GW spectrum. Serendipitously, the nano-Hertz range
coincides with the Hubble scale during the cosmological quantum chromodynamics
(QCD) phase transition. The influence of the QCD phase transition can modify
the spectrum of induced GWs within the nano-Hertz frequency range,
necessitating careful analysis. We estimate GWs induced by power-law power
spectra of primordial curvature perturbations taking account of the QCD phase
transition. Then we translate the implication of the NANOGrav data into the
constraint on the power spectrum of the primordial curvature perturbation,
which suggests that one may miss the correct interpretation if neglecting the
QCD effect. We also derive fitting formulae for their amplitude and scale
dependence, helping to update the constraint in future experiments.Comment: 7 pages, 5 figure
Bazedoxifene, a selective estrogen receptor modulator, reduces cerebral aneurysm rupture in Ovariectomized rats.
BackgroundEstrogen deficiency is thought to be responsible for the higher frequency of aneurysmal subarachnoid hemorrhage in post- than premenopausal women. Estrogen replacement therapy appears to reduce this risk but is associated with significant side effects. We tested our hypothesis that bazedoxifene, a clinically used selective estrogen receptor (ER) modulator with fewer estrogenic side effects, reduces cerebral aneurysm rupture in a new model of ovariectomized rats.MethodsTen-week-old female Sprague-Dawley rats were subjected to ovariectomy, hemodynamic changes, and hypertension to induce aneurysms (ovariectomized aneurysm rats) and treated with vehicle or with 0.3 or 1.0 mg/kg/day bazedoxifene. They were compared with sham-ovariectomized rats subjected to hypertension and hemodynamic changes (HT rats). The vasoprotective effects of bazedoxifene and the mechanisms underlying its efficacy were analyzed.ResultsDuring 12 weeks of observation, the incidence of aneurysm rupture was 52% in ovariectomized rats. With no effect on the blood pressure, treatment with 0.3 or 1.0 mg/kg/day bazedoxifene lowered this rate to 11 and 17%, almost the same as in HT rats (17%). In ovariectomized rats, the mRNA level of ERα, ERβ, and the tissue inhibitor of metalloproteinase-2 was downregulated in the cerebral artery prone to rupture at 5 weeks after aneurysm induction; the mRNA level of interleukin-1β and the matrix metalloproteinase-9 was upregulated. In HT rats, bazedoxifene restored the mRNA level of ERα and ERβ and decreased the level of interleukin-1β and matrix metalloproteinase-9. These findings suggest that bazedoxifene was protective against aneurysmal rupture by alleviating the vascular inflammation and degradation exacerbated by the decrease in ERα and ERβ.ConclusionsOur observation that bazedoxifene decreased the incidence of aneurysmal rupture in ovariectomized rats warrants further studies to validate this response in humans
Manipulating ionization path in a Stark map: Stringent schemes for the selective field ionization in highly excited Rb Rydberg atoms
We have developed a quite stringent method in selectivity to ionize the low
angular- momentum () states which lie below and above the adjacent
manifold in highly excited Rb Rydberg atoms. The method fully exploits the
pulsed field-ionization characteristics of the manifold states in high
slew-rate regime: Specifically the low state below (above) the adjacent
manifold is firstly transferred to the lowest (highest) state in the manifold
via the adiabatic transition at the first avoided crossing in low slew-rate
regime, and then the atoms are driven to a high electric field for ionization
in high slew-rate regime. These extreme states of the manifold are ionized at
quite different fields due to the tunneling process, resulting in thus the
stringent selectivity. Two manipulation schemes to realize this method actually
are demonstrated here experimentally.Comment: 10 pages, 4 figure
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