Bender et al. [Phys. Rev. Lett. 80, 5243 (1998)] have developed PT-symmetric quantum theory as an extension of quantum theory to non-Hermitian Hamiltonians. We show that when this model has a local PT symmetry acting on composite systems, it violates the nonsignaling principle of relativity. Since the case of global PT symmetry is known to reduce to standard quantum mechanics A. Mostafazadeh [J. Math. Phys. 43, 205 (2001)], this shows that the PT-symmetric theory is either a trivial extension or likely false as a fundamental theory.
Exfoliation syndrome (XFS) is the commonest known risk factor for secondary glaucoma and a significant cause of blindness worldwide. Variants in two genes, LOXL1 and CACNA1A have been previously associated with XFS. To further elucidate the genetic basis of XFS, we collected a global sample of XFS cases to refine the association at LOXL1, which previously showed inconsistent results between populations, and to identify new variants associated with XFS. We identified a rare, protective allele at LOXL1 (p.407Phe, OR = 25, P =2.9 × 10−14) through deep resequencing of XFS cases and controls from 9 countries. This variant results in increased cellular adhesion strength compared to the wild-type (p.407Tyr) allele. A genome-wide association study (GWAS) of XFS cases and controls from 24 countries followed by replication in 18 countries identified seven genome-wide significant loci (P < 5 × 10−8). Index variants at the new loci map to chromosomes 13q12 (POMP), 11q23.3 (TMEM136), 6p21 (AGPAT1), 3p24 (RBMS3) and 5q23 (near SEMA6A). These findings provide biological insights into the pathology of XFS, and highlight a potential role for naturally occurring rare LOXL1 variants in disease biology.
We study the low-intensity light pulse propagation through an asymmetric double quantum well via Fano-type interference based on intersubband transitions. The propagation of the pulse across the quantum well is studied analytically and numerically with the coupled Maxwell-Schrödinger equations. We show the generation of ultraslow bright and dark optical solitons in this system. Whether the solitons are dark and bright can be controlled by the ratio of dipole moments of the intersbband transitions. Such investigation of ultraslow optical solitons in the present work may lead to important applications such as high-fidelity optical delay lines and optical buffers in semiconductor quantum wells structure.
We theoretically investigate the simultaneous formation and stable propagation of slow optical soliton pairs in semiconductor quantum dots with a four-level biexciton-exciton cascade configuration. Owing to the destructive interference set up by two continuous wave control fields that couple to a biexciton state, the linear as well as nonlinear dispersion can be dramatically enhanced simultaneously with the absorptions of two weak probe fields being almost suppressed. These results reveal that the detrimental distortions of the two weak-pulsed probe fields due to dispersion effects can be well balanced by the self-phase modulation effect under very low input light intensity, which leads to the slow temporal optical soliton pairs with matched group velocity and amplitude. We also show that the propagation of slow optical solitons can be strongly modified by the biexciton coherence.
Disorder
is emerging as a strategy for fabricating random laser
sources with very promising materials, such as perovskites, for which
standard laser cavities are not effective or too expensive. We need,
however, different fabrication protocols and technologies for reducing
the laser threshold and controlling its emission. Here, we demonstrate
an effectively solvent-engineered method for high-quality perovskite
thin films on a flexible polyimide substrate. The fractal perovskite
thin films exhibit excellent optical properties at room temperature
and easily achieve lasing action without any laser cavity above room
temperature with a low pumping threshold. The lasing action is also
observed in curved perovskite thin films on flexible substrates. The
lasing threshold can be further reduced by increasing the local curvature,
which modifies the scattering strengths of the bent thin film. We
also show that the curved perovskite lasers are extremely robust with
respect to repeated deformations. Because of the low spatial coherence,
these curved random laser devices are efficient and durable speckle-free
light sources for applications in spectroscopy, bioimaging, and illumination.
Intravitreal bevacizumab is now a frequently used adjunct for the treatment of NVG. Eyes must be monitored closely after initial injection of intravitreal bevacizumab, regardless of initial angle status, as many may still require surgery to lower IOP or repeat injections of intravitreal bevacizumab.
Our understanding of pseudoexfoliation glaucoma has recently been significantly advanced by cutting edge molecular and genetic approaches to studying this sight threatening disease. An increased understanding of the molecular pathophysiology of pseudoexfoliation glaucoma will lead to improved management and diagnosis and new treatments for pseudoexfoliation glaucoma.
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