2,329 research outputs found
Positivity Bounds on Higgs-Portal Dark Matter
We consider the positivity bounds for WIMP scalar dark matter with effective
Higgs-portal couplings up to dimension-8 operators. Taking the superposed
states for Standard Model Higgs and scalar dark matter, we show that the part
of the parameter space for the effective couplings, otherwise unconstrained by
phenomenological bounds, is ruled out by the positivity bounds on the
dimension-8 derivative operators. We find that dark matter relic density,
direct and indirect detection and LHC constraints are complementary to the
positivity bounds in constraining the effective Higgs-portal couplings. In the
effective theory obtained from massive graviton or radion, there appears a
correlation between dimension-8 operators and other effective Higgs-portal
couplings for which the strong constraint from direct detection can be evaded.
Nailing down the parameter space mainly by relic density, direct detection and
positivity bounds, we find that there are observable cosmic ray signals coming
from the dark matter annihilations into a pair of Higgs bosons, or .Comment: 31 pages, 6 figures, v2: one-loop corrections to the positivity
bounds added, version to be published in JHE
Muon and Proton Lifetime in SUSY SU(5) GUTs with Split Superpartners
We consider the interplay of the muon anomaly and the proton decay in
the SUSY SU(5) GUTs with generation-independent scalar soft masses. In these
scenarios, we introduce a number of messenger fields with
doublet-triplet splitting in general gauge mediation to transmit SUSY breaking
to the visible sector by gauge loops. As a result, squarks and sleptons receive
generation-independent soft SUSY breaking masses, which are split already at
the messenger scale. Taking into account the perturbative unification of gauge
couplings as well as the bounds from electroweak precision and vacuum stability
bounds, we showed the parameter space in general gauge mediation to explain the
muon anomaly with smuon and sneutrino loops while evading the strong
bounds on squarks and gluinos from the Large Hadron Collider. We also obtained
the dominant Higgsino contributions to the proton decay mode, , with general generation-independent sparticle masses for squarks
and sleptons. Even for split scalar soft masses in our model, however, we found
that the bounds from the proton decay are satisfied only if the effective
Yukawa couplings of the colored Higgsinos are suppressed further by a factor of
order . We illustrated how such a suppression factor is
realized in orbifold GUTs in the extra dimension where the colored Higgsinos in
the bulk are not coupled to the matter fields localized at the orbifold fixed
points at the leading order.Comment: 35 pages, 8 figures, v2: typos fixed and reference updated, v3:
version to appear in Phys. Rev.
The lepton portals for muon , boson mass and dark matter
We propose a novel model for lepton flavor and dark matter based on the
gauge symmetry and vector-like leptons in its fundamental
representations. We introduce a dark Higgs doublet and a Higgs
bi-doublet for the mass mixing between the vector-like lepton and the lepton.
As a result, the seesaw lepton masses are generated and there are sizable
one-loop contributions to the muon via the gauge bosons and the
relatively heavy vector-like lepton, as indicated in Fermilab E989. The
tree-level mass mixing between the boson and the isospin neutral gauge
boson of in our model accounts for the shift in the boson mass,
being consistent with Tevatron CDFII. Finally, we show that the isospin charged
gauge boson of becomes a plausible candidate for dark matter with a
small mass splitting tied up to the modified boson mass, and there is a
viable parameter space where the favored corrections to the muon and the
boson mass and the dark matter constraints are simultaneously fulfilled.Comment: 33 pages, 4 figures, v2: references added, v3: version to appear in
Phys. Rev.
The Rhizome Mixture of Anemarrhena asphodeloides
We investigated the effect of DWac on the gut microbiota composition in mice with 2,3,6-trinitrobenzenesulfonic acid- (TNBS-) induced colitis. Treatment with DWac restored TNBS-disturbed gut microbiota composition and attenuated TNBS-induced colitis. Moreover, we examined the effect of DWac in mice with mesalazine-resistant colitis (MRC). Intrarectal injection of TNBS in MRC mice caused severe colitis, as well as colon shortening, edema, and increased myeloperoxidase activity. Treatment with mesalazine (30 mg/kg) did not attenuate TNBS-induced colitis in MRC mice, whereas treatment with DWac (30 mg/kg) significantly attenuated TNBS-induced colitis. Moreover, treatment with the mixture of mesalazine (15 mg/kg) and DWac (15 mg/kg) additively attenuated colitis in MRC mice. Treatment with DWac and its mixture with mesalazine inhibited TNBS-induced activation of NF-κB and expression of M1 macrophage markers but increased TNBS-suppressed expression of M2 macrophage markers. Furthermore, these inhibited TNBS-induced T-bet, RORγt, TNF-α, and IL-17 expression but increased TNBS-suppressed Foxp3 and IL-10 expression. However, Th2 cell differentiation and GATA3 and IL-5 expression were not affected. These findings suggest that DWac can ameliorate MRC by increasing the polarization of M2 macrophage and correcting the disturbance of gut microbiota and Th1/Th17/Treg, as well as additively attenuating MRC along with mesalazine
AcetonitrileÂ{3-[bisÂ(2-pyridylÂmethyl-κN)amino-κN]propanol-κO}(perchlorato-κO)copper(II) perchlorate
In the title compound, [Cu(ClO4)(C2H3N)(C15H19N3O)]ClO4, the CuII ion is coordinated by three N atoms and a hydroxyl-O atom of the tetraÂdentate ligand, an O atom of a perchlorate ion and an N atom of an acetonitrile ligand giving a tetraÂgonally distorted octaÂhedral environment around the copper(II) atom. There is an offset inter-complex face-to-face π–π interÂaction [centroid–centroid distance = 3.718 (2) Å] involving one of the pyridine rings of the ligand as well as an intra-complex O—H⋯O hydrogen-bonding interÂaction between the coordinated hydroxyl group of the ligand and the perchlorate counter-ion
Short Term Effect and Safety of Antidiuretic Hormone in the Patients with Nocturia
Purpose To investigate the short-term safety of antidiuretic hormone in elderly patients with nocturnal polyuria, focus on hyponatremia and others electrolytes disturbances and to assess short-term effects on nocturnal urine output and number of nocturnal voids. Methods Between June 2005 and August 2006, a total of 34 patients with nocturnal polyuria were orally administered 0.2 mg desmopressin tablet at bedtime for two weeks. Serum sodium, others electrolytes, urine sodium and urine osmolarity were assessed in the third days, one week and two weeks after treatment with desmopressin and compared adult group (<65 years of age) with elderly group (≥65 years of age). We assessed the effect of desmopressin using a frequency-volume charts and analysed. Results In total 34 patients (20 adult, 14 elderly) were analyzed. Desmopressin treatment did not significantly change serum and urine electrolytes include soduim concentration in elderly patients comparied with adult patients. Serum sodium concentration below normal range was recorded in 2 patients in elderly group, but no serious adverse events occurred and recovered without sequelae. The mean number of nocturnal voids decresed (54% reduction) and nocturnal urine output decreased (57% reduction) after using desmopressin. Conclusions Desmopressin was well tolerated and effective in elderly patients with nocturnal polyuria without clinically significant hyponatremia
Whole-brain imaging with receive-only multichannel top-hat dipole antenna RF coil at 7Â T MRI
This work investigates the construction and performance of an eight-channel top-hat dipole receiver RF coil with a capacitive plate to increase the longitudinal whole-brain coverage and receiver sensitivity gain in the brain at 7 T MRI. The construction method for top-hat dipole-based receiver RF coil by adjusting the length and structure corresponding to each channel consists of tuning, matching, balun, and detuning circuitry. Electromagnetic simulations were analyzed on a 3-D human model to evaluate B1+ efficiency and specific absorption rate deposition. Coil performance was evaluated in the human head imaging in vivo. EM simulation results indicated a higher B1− sensitivity in the brain and z-directional coverage of the proposed eight-channel receiver RF coil. The MR images were acquired with an identical field of view showing the receiver coverage improvement in the brain when capacitive plates are used. The MR images also show the clear visibility of the complete set of the cervical vertebrae as well as the spinal cord. The acquired MRI results demonstrate the capability of the proposed RF coil to increase the receiver coverage in the longitudinal direction. Moreover, the B1+ efficiency, as well as receiver sensitivity in the brain, can be substantially improved with the use of multilayered capacitive plates of proper shape and size in conjunction with an RF coil
Discovery of noncanonical translation initiation sites through mass spectrometric analysis of protein N termini
Translation initiation generally occurs at AUG codons in eukaryotes, although it has been shown that non-AUG or non-canonical translation initiation can also occur. However, the evidence for noncanonical translation initiation sites (TISs) is largely indirect and based on ribosome profiling (Ribo-seq) studies. Here, using a strategy specifically designed to enrich N termini of proteins, we demonstrate that many human proteins are translated at noncanonical TISs. The large majority of TISs that mapped to 5' untranslated regions were noncanonical and led to N-terminal extension of annotated proteins or translation of upstream small open reading frames (uORF). It has been controversial whether the amino acid corresponding to the start codon is incorporated at the TIS or methionine is still incorporated. We found that methionine was incorporated at almost all noncanonical TISs identified in this study. Comparison of the TISs determined through mass spectrometry with ribosome profiling data revealed that about two-thirds of the novel annotations were indeed supported by the available ribosome profiling data. Sequence conservation across species and a higher abundance of noncanonical TISs than canonical ones in some cases suggests that the noncanonical TISs can have biological functions. Overall, this study provides evidence of protein translation initiation at noncanonical TISs and argues that further studies are required for elucidation of functional implications of such noncanonical translation initiation
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