5,571 research outputs found
Supersymmetric mode converters
Originally developed in the context of quantum field theory, the concept of
supersymmetry (SUSY) can be used to systematically design a new class of
optical structures. In this work, we demonstrate how key features arising from
optical supersymmetry can be exploited to control the flow of light for mode
division multiplexing applications. Superpartner configurations are
experimentally realized in coupled optical networks, and the corresponding
light dynamics in such systems are directly observed. We show that SUSY can be
judiciously utilized to remove the fundamental mode of a multimode optical
structure, while establishing global phase matching conditions for the
remaining set of modes. Along these lines, supersymmetry may serve as a
promising platform for a new generation of versatile optical components with
novel properties and functionalities.Comment: 14 pages, 4 figure
Drug-induced Lung Disease Associated With Ustekinumab in a Pediatric Patient With Crohn Disease.
Contractile force is enhanced in Aortas from pendrin null mice due to stimulation of angiotensin II-dependent signaling.
Pendrin is a Cl-/HCO3- exchanger expressed in the apical regions of renal intercalated cells. Following pendrin gene ablation, blood pressure falls, in part, from reduced renal NaCl absorption. We asked if pendrin is expressed in vascular tissue and if the lower blood pressure observed in pendrin null mice is accompanied by reduced vascular reactivity. Thus, the contractile responses to KCl and phenylephrine (PE) were examined in isometrically mounted thoracic aortas from wild-type and pendrin null mice. Although pendrin expression was not detected in the aorta, pendrin gene ablation changed contractile protein abundance and increased the maximal contractile response to PE when normalized to cross sectional area (CSA). However, the contractile sensitivity to this agent was unchanged. The increase in contractile force/cross sectional area observed in pendrin null mice was due to reduced cross sectional area of the aorta and not from increased contractile force per vessel. The pendrin-dependent increase in maximal contractile response was endothelium- and nitric oxide-independent and did not occur from changes in Ca2+ sensitivity or chronic changes in catecholamine production. However, application of 100 nM angiotensin II increased force/CSA more in aortas from pendrin null than from wild type mice. Moreover, angiotensin type 1 receptor inhibitor (candesartan) treatment in vivo eliminated the pendrin-dependent changes contractile protein abundance and changes in the contractile force/cross sectional area in response to PE. In conclusion, pendrin gene ablation increases aorta contractile force per cross sectional area in response to angiotensin II and PE due to stimulation of angiotensin type 1 receptor-dependent signaling. The angiotensin type 1 receptor-dependent increase in vascular reactivity may mitigate the fall in blood pressure observed with pendrin gene ablation
NearâIntrinsic Photoâ and Electroluminescence from SingleâWalled Carbon Nanotube Thin Films on BCBâPassivated Surfaces
Their outstanding electrical and optical properties make semiconducting single-walled carbon nanotubes (SWCNTs) highly suitable for charge transport and emissive layers in near-infrared optoelectronic devices. However, the luminescence spectra of SWCNT thin films on commonly used glass and Si/SiO2 substrates are often compromised by broadening of the main excitonic emission and unwanted low-energy sidebands. Surface passivation with a commercially available, low dielectric constant, cross-linked bis-benzocyclobutene-based polymer (BCB) enhances the emission properties of SWCNTs to the same level as hexagonal boron nitride (h-BN) flakes do. The presence of BCB suppresses sideband emission, especially from the Y1 band, which is attributed to defects introduced by the interaction of the nanotube lattice with oxygen-containing terminal groups of the substrate surface. The facile and reproducible deposition of homogeneous BCB films over large areas combined with their resistance against common solvents and chemicals employed during photolithography make them compatible with standard semiconductor device fabrication. Utilizing this approach, light-emitting (6,5) SWCNT network field-effect transistors are fabricated on BCB-treated glass substrates with excellent electrical characteristics and near-intrinsic electroluminescence. Hence, passivation with BCB is proposed as a standard treatment for substrates used for spectroscopic investigations of and optoelectronic devices with SWCNTs and other low-dimensional emitters
The Semileptonic Decays and from Lattice QCD
We present a lattice QCD calculation of the form factors and differential
decay rates for semileptonic decays of the heavy-light mesons and to
the final state . The results are obtained with three methodological
improvements over previous lattice calculations: a matching procedure that
reduces heavy-quark lattice artifacts, the first study of lattice-spacing
dependence, and the introduction of kinematic cuts to reduce model dependence.
We show that the main systematics are controllable (within the quenched
approximation) and outline how the calculations could be improved to aid
current experiments in the determination of~ and~.Comment: 35 pp, 12 fig
TGF-Beta Modulates the Integrity of the Blood Brain Barrier In Vitro, and Is Associated with Metabolic Alterations in Pericytes
The bloodâbrain barrier (BBB) is a selectively permeable boundary that separates the
circulating blood from the extracellular fluid of the brain and is an essential component for brain
homeostasis. In glioblastoma (GBM), the BBB of peritumoral vessels is often disrupted. Pericytes,
being important to maintaining BBB integrity, can be functionally modified by GBM cells which
induce proliferation and cell motility via the TGF-ÎČ-mediated induction of central epithelial to
mesenchymal transition (EMT) factors. We demonstrate that pericytes strengthen the integrity of
the BBB in primary endothelial cell/pericyte co-cultures as an in vitro BBB model, using TEER
measurement of the barrier integrity. In contrast, this effect was abrogated by TGF-ÎČ or conditioned
medium from TGF-ÎČ secreting GBM cells, leading to the disruption of a so far intact and tight BBB.
TGF-ÎČ notably changed the metabolic behavior of pericytes, by shutting down the TCA cycle, driving
energy generation from oxidative phosphorylation towards glycolysis, and by modulating pathways
that are necessary for the biosynthesis of molecules used for proliferation and cell division. Combined
metabolomic and transcriptomic analyses further underscored that the observed functional and
metabolic changes of TGF-ÎČ-treated pericytes are closely connected with their role as important
supporting cells during angiogenic processes
(1S,2R,4S)-1-[(BenzylÂamino)ÂmethÂyl]-4-(prop-1-en-2-yl)cycloÂhexane-1,2-diol
The title compound, C17H25NO2, was synthesized by epoxidation of the double bond of (S)-perillyl alcohol [(S)-4-isopropenyl-1-cycloÂhexenylÂmethanol], followed by the oxirane ring-opening by benzylÂamine using [Ca(CF3CO2)2] as catalyst under solvent-free condition at 313â
K. The molÂecular conformation is stabilized by an intraÂmolecular OâHâŻN hydrogen bond. In the crystal, molÂecules are linked by interÂmolecular NâHâŻO hydrogen bonds, forming chains parallel to the a axis, which are further connected by OâHâŻO hydrogen bonds into sheets parallel to (010). The absolute configuration of the molÂecule is known from the synthetic procedure
Direct CP Violation in B -> X_s gamma Decays as a Signature of New Physics
We argue that the observation of a sizable direct CP asymmetry A_{CP} in the
inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the
Standard Model, A_{CP} can be calculated reliably and is found to be below 1%
in magnitude. In extensions of the Standard Model with new CP-violating
couplings, large CP asymmetries are possible without conflicting with the
experimental value of the branching ratio for the decays B -> X_s gamma. In
particular, large asymmetries arise naturally in models with enhanced
chromo-magnetic dipole operators. Some generic examples of such models are
explored and their implications for the semileptonic branching ratio and charm
yield in B decays discussed.Comment: several references added and some numerical results updated to
include QED corrections (version to appear in Physical Review D
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