7,334 research outputs found
Collider Detection of Dark Matter Electromagnetic Anapole Moments
Dark matter that interacts with the Standard Model by exchanging photons
through higher multipole interactions occurs in a wide range of both strongly
as well as weakly coupled hidden sector models. We study the collider detection
prospects of these candidates, with a focus on Majorana dark matter that
couples through the anapole moment. The study is conducted at the effective
field theory level with the mono- signature incorporating varying levels of
systematic uncertainties at the high-luminosity LHC. The projected collider
reach on the anapole moment is then compared to the reach coming from direct
detection experiments like LZ. Finally, the analysis is applied to a weakly
coupled completion with leptophilic dark matter.Comment: 24 pages, 9 figure
Thermal Control of the Intrinsic Magnetic Damping in a Ferromagnetic Metal
We report experiments on the control of intrinsic magnetic damping by thermal torque effects produced by the spin Seebeck effect and the anomalous Nernst effect in a thin layer of a ferromagnetic metal (Permalloy (Py), ). Damping is measured in ferromagnetic resonance (FMR) experiments on a sample excited by microwave radiation and detected by the dc-voltage-generated spin rectification and magnonic charge pumping in the Py film. Application of a temperature gradient in the longitudinal configuration increases or decreases the dc-voltage line width, depending on the sign of the thermal gradient, demonstrating that the magnetic damping in Py is controlled by currents generated by thermal effects. The absolute values of the line-width changes in Py may reach 1 order of magnitude larger than in the ferrimagnetic insulator yttrium iron garnet. The large change in magnetic damping is interpreted as a superposition of different phenomena in the same metallic ferromagnet
Intranasal fosphenytoin: the promise of phosphate esters in nose-to-brain delivery of poorly soluble drugs
Intranasal administration could increase both safety and efficacy of drugs acting on the central nervous system, but low solubility severely limits administration through this route. Phenytoin’s prodrug, fosphenytoin, is hydrophilic and freely soluble in water, but less permeable since it is dianionic. We aimed to assess whether this phosphoester prodrug could be a suitable alternative to phenytoin in intranasal delivery. Secondly, we aimed to compare simple formulation strategies in fosphenytoin delivery.
Fosphenytoin formulations containing thermosensitive and/or mucoadhesive (hydroxypropyl methylcellulose, HPMC) polymers were developed, guided by viscosity, gelling temperatures, osmolality, and in vitro drug release tests. Then, a pharmacokinetic study was performed, comparing an intravenous fosphenytoin solution, an intranasal fosphenytoin solution, and intranasal fosphenytoin mucoadhesive formulations with or without albumin.
Formulations containing HPMC allowed high drug strengths, and had a relatively fast release profile, which was not changed by albumin. Intranasal administration of a formulation with HPMC and albumin prolonged drug concentration over time and led to complete or even increased absolute bioavailability. Moreover, phenytoin’s blood levels did not reach the high peak obtained with intravenous administration. In conclusion, the use of phosphate ester prodrugs could be an efficient and safe strategy to increase the intranasal bioavailability of poorly soluble drugs.European Regional Development funds through the Operational Programme “Centro 2020”, through the ICON project (Interdisciplinary Challenges On Neurodegeneration, reference CENTRO-01-0145-FEDER-000013).info:eu-repo/semantics/acceptedVersio
Influence of the external pressure on the quantum correlations of molecular magnets
The study of quantum correlations in solid state systems is a large avenue
for research and their detection and manipulation are an actual challenge to
overcome. In this context, we show by using first-principles calculations on
the prototype material KNaCuSiO that the degree of quantum
correlations in this spin cluster system can be managed by external hydrostatic
pressure. Our results open the doors for research in detection and manipulation
of quantum correlations in magnetic systems with promising applications in
quantum information science
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