1,517 research outputs found
Wide-angle perfect absorber/thermal emitter in the THz regime
We show that a perfect absorber/thermal emitter exhibiting an absorption peak
of 99.9% can be achieved in metallic nanostructures that can be easily
fabricated. The very high absorption is maintained for large angles with a
minimal shift in the center frequency and can be tuned throughout the visible
and near-infrared regime by scaling the nanostructure dimensions. The stability
of the spectral features at high temperatures is tested by simulations using a
range of material parameters.Comment: Submitted to Phys. Rev. Let
A geometric view of cryptographic equation solving
This paper considers the geometric properties of the Relinearisation algorithm and of the XL algorithm used in cryptology for equation solving. We give a formal description of each algorithm in terms of projective geometry, making particular use of the Veronese variety. We establish the fundamental geometrical connection between the two algorithms and show how both algorithms can be viewed as being equivalent to the problem of finding a matrix of low rank in the linear span of a collection of matrices, a problem sometimes known as the MinRank problem. Furthermore, we generalise the XL algorithm to a geometrically invariant algorithm, which we term the GeometricXL algorithm. The GeometricXL algorithm is a technique which can solve certain equation systems that are not easily soluble by the XL algorithm or by Groebner basis methods
Synthetic dimensions and spin-orbit coupling with an optical clock transition
We demonstrate a novel way of synthesizing spin-orbit interactions in
ultracold quantum gases, based on a single-photon optical clock transition
coupling two long-lived electronic states of two-electron Yb atoms. By
mapping the electronic states onto effective sites along a synthetic
"electronic" dimension, we have engineered synthetic fermionic ladders with
tunable magnetic fluxes. We have detected the spin-orbit coupling with
fiber-link-enhanced clock spectroscopy and directly measured the emergence of
chiral edge currents, probing them as a function of the magnetic field flux.
These results open new directions for the investigation of topological states
of matter with ultracold atomic gases.Comment: Minor changes with respect to v1 (we have corrected some typos, fixed
the use of some mathematical symbols, added one reference
Linear aerospike engine study
Parametric data on split-combustor linear engine propulsion systems are presented for use in mixed-mode single-stage-to-orbit (SSTO) vehicle studies. Preliminary design data for two selected engine systems are included. The split combustor was investigated for mixed-mode operations with oxygen/hydrogen propellants used in the inner combustor in Mode 2, and in conjunction with either oxygen/RP-1, oxygen/RJ-5, O2/CH4, or O2/H2 propellants in the outer combustor for Mode 1. Both gas generator and staged combustion power cycles were analyzed for providing power to the turbopumps of the inner and outer combustors. Numerous cooling circuits and cooling fluids (propellants) were analyzed and hydrogen was selected as the preferred coolant for both combustors and the linear aerospike nozzle. The maximum operating chamber pressure was determined to be limited by the availability of hydrogen coolant pressure drop in the coolant circuit
Natalizumab induced blood eosinophilia: A retrospective pharmacovigilance cohort study and review of the literature.
OBJECTIVE
To describe frequency of natalizumab related eosinophilia and clinical symptoms of eosinophilic disease in our monocentric cohort.
METHODS
Comparison of clinical characteristics of 115 natalizumab treated and 116 untreated RRMS patients and review of literature.
RESULTS
38% of natalizumab treated patients had eosinophilia, which occurred significantly more frequently compared to untreated MS patients (3%, p-value<0.001). In symptomatic patients, mean eosinophil counts were significantly higher than in asymptomatic patients and symptoms developed within one year.
DISCUSSION
Eosinophilia is a side effect of natalizumab and mostly asymptomatic. However, few patients develop within one year after start of natalizumab an eosinophilic disease as severe side effect
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