294 research outputs found
Local Entanglement and quantum phase transition in spin models
Due to the phase interference of electromagnetic wave, one can recover the
total image of one object from a small piece of holograph, which records the
interference pattern of two laser light reflected from it. Similarly, the
quantum superposition principle allows us to derive the global phase diagram of
quantum spin models by investigating a proper local measurement. In the present
paper, we study the two-site entanglement in the antifferomagnetic spin models
with both spin-1/2 and 1. We show that its behaviors reveal some important
information on the global properties and the quantum phase transition of these
systems.Comment: 6 pages, 7 figure
Entanglement and quantum phase transitions
We examine several well known quantum spin models and categorize behavior of
pairwise entanglement at quantum phase transitions. A unified picture on the
connection between the entanglement and quantum phase transition is given.Comment: 4 pages, 3 figure
The ground state entanglement in the model
In this paper, we investigate spin entanglement in the model defined on
a -dimensional bipartite lattice. The concurrence, a measure of the
entanglement between two spins, is analyzed. We prove rigorously that the
ground state concurrence reaches maximum at the isotropic point. For
dimensionality , the concurrence develops a cusp at the isotropic
point and we attribute it to the existence of magnetic long-range order.Comment: 5 pages, 2 figure
Constrain on possible pairing symmetry in a two-orbital model of FeAs-based superconductors
In this work, we establish a few exact identities through commutation of
intra-orbital and inter-orbital on-site pairings with a two-orbital model
describing newly discovered FeAs-based superconductors. Applying the conclusion
drawn from rigorous relation and physical interpretation, we give constraints
on the possible symmetries of the superconducting pairing of the model. Hence
the favorable pairings in newly discovered high-temperature oxypnictide
superconductors are proposed.Comment: 5 pages, 2 figure
N-Acetylcysteine Suppresses LPS-Induced Pathological Angiogenesis
Background/Aims: Angiogenesis is a key feature during embryo development but is also part of the pathogenesis of cancer in adult life. Angiogenesis might be modulated by inflammation. Methods: We established an angiogenesis model in chick chorioallantoic membrane (CAM) induced by the exposure of lipopolysaccharide (LPS), and analyzed the effects of the antioxidant N-acetylcysteine (NAC) on angiogenesis in this model as well as on the expression of key genes known to involved in the regulation of angiogenesis. Results: Treatment with NAC was able to normalize LPS induced angiogenesis and restore the LPS-induced damage of vascular epithelium in chick CAM. Using quantitative PCR, we showed that NAC administration normalized the LPS induced expression of Keap1-Nrf2 signaling and oxidative stress key enzyme gene expressions (SOD, GPx and YAP1). Conclusion: We established a LPS-induced angiogenesis model in chick CAM. NAC administration could effectively inhibit LPS-induced angiogenesis and restore the integrity of endothelium on chick CAM. LPS exposure caused an increased expression of genes involved in oxidative stress in chick CAM. NAC administration could abolish this effect
Lipopolysaccharides (LPS) Induced Angiogenesis During Chicken Embryogenesis is Abolished by Combined ETA/ETB Receptor Blockade
One-stage coclear implantation via a facial recess approach in children with otitis media with effusion
AbstractObjectiveTo investigate surgical indications, operative techniques, complications and auditory and speech rehabilitation for cochlear implant (CI) in children with otitis media with effusion (OME).Material and methodsThis is a retrospective review of records of 24children with bilateral profound sensorineural hearing loss and OME who were implanted during January 2011 to November 2014 in the Department of Otorhinolaryngology and Head and Neck Surgery at the PLA Hospital, using one-stage implantation via the facial recess approach and round window insertion. The incus was removed in 8 cases during the implantation procedure. Local infiltration of dexamethasone and adrenaline in the middle ear was also performed. Postoperative complications were examined. Preoperative and postoperative questionnaires including Categories of Auditory Performance (CAP), Speech Intelligibility Rating (SIR), and the Meaningful Auditory Integration Scale (MAIS) were collected.ResultsAll electrodes were implanted successfully without any immediate or delayed complications. Inflammatory changes of middle ear mucosa with effusion were noted in all implanted ears. The scores of post-implant CAP and SIR increased significantly in all 24 cases (t = â25.95 and â14.09, respectively for CAP and SIR, p < 0.05).ConclusionsOne-stage CI via the facial recess approach with round window insertion is safe and effective in cochlear implant candidates with OME, as seen in the 24 children in our study who achieved improved auditory performance and speech intelligibility after CI
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