Minimum Entangling Power is Close to Its Maximum

Given a quantum gate $U$ acting on a bipartite quantum system, its maximum (average, minimum) entangling power is the maximum (average, minimum) entanglement generation with respect to certain entanglement measure when the inputs are restricted to be product states. In this paper, we mainly focus on the 'weakest' one, i.e., the minimum entangling power, among all these entangling powers. We show that, by choosing von Neumann entropy of reduced density operator or Schmidt rank as entanglement measure, even the 'weakest' entangling power is generically very close to its maximal possible entanglement generation. In other words, maximum, average and minimum entangling powers are generically close. We then study minimum entangling power with respect to other Lipschitiz-continuous entanglement measures and generalize our results to multipartite quantum systems. As a straightforward application, a random quantum gate will almost surely be an intrinsically fault-tolerant entangling device that will always transform every low-entangled state to near-maximally entangled state.Comment: 26 pages, subsection III.A.2 revised, authors list updated, comments are welcom

Investigation of endobronchial tuberculosis diagnoses in 22 cases

Abstract Background Endobronchial tuberculosis (EBTB) is a special form of pulmonary tuberculosis. In spite of much progress in the diagnosis of this disease in past years, delayed or mistaken diagnosis is still commonly seen. Objective The aim of this study is to try to find out some useful clues for the diagnosis of EBTB, especially the early diagnosis. Methods The medical records of patients with EBTB were analyzed retrospectively. Results: The male-to-female ratio was 1:2.2 out of 22 patients. Patients aged below 60-years-old constituted 72.7% of the cases. 22.7% of these patients were smokers. The male-to-female ratio of smokers was 4:1. 68.2% of these patients tested all showed negative result for the HIV test. The frequent complaints were cough, sputum, shortness of breath and fever, and antibiotic treatments were usually inefficacious. Multiple lobes lesion, exudative shadow and atelectasis were the frequent radiological findings. Acid-fast bacilli staining for sputum smear was positive in only 13.6% of these patients. Tuberculin skin test was positive in 59.1% of these patients. Granular lesion was the most common bronchoscopic appearance in these patients. Histological changes showed distinctive tuberculose lesion in 72.2% of 18 patients undergoing bronchoscopic biopsy. Conclusion The diagnosis of EBTB is easily delayed or mistaken because of nonspecific clinical manifestations and the low incidence of positive acid-fast bacilli staining. A high index of awareness of this disease is required for diagnosis. Bronchoscopy should be performed as soon as possible in suspected patients, especially when patients present positive tuberculin skin test or no response to antibiotic treatments.</p

Entanglement can completely defeat quantum noise

We describe two quantum channels that individually cannot send any information, even classical, without some chance of decoding error. But together a single use of each channel can send quantum information perfectly reliably. This proves that the zero-error classical capacity exhibits superactivation, the extreme form of the superadditivity phenomenon in which entangled inputs allow communication over zero capacity channels. But our result is stronger still, as it even allows zero-error quantum communication when the two channels are combined. Thus our result shows a new remarkable way in which entanglement across two systems can be used to resist noise, in this case perfectly. We also show a new form of superactivation by entanglement shared between sender and receiver.Comment: 4 pages, 1 figur

Superactivation of the Asymptotic Zero-Error Classical Capacity of a Quantum Channel

The zero-error classical capacity of a quantum channel is the asymptotic rate at which it can be used to send classical bits perfectly, so that they can be decoded with zero probability of error. We show that there exist pairs of quantum channels, neither of which individually have any zero-error capacity whatsoever (even if arbitrarily many uses of the channels are available), but such that access to even a single copy of both channels allows classical information to be sent perfectly reliably. In other words, we prove that the zero-error classical capacity can be superactivated. This result is the first example of superactivation of a classical capacity of a quantum channel.Comment: 24 pages. Despite the similar title, contains different results from arXiv:0906.2527. See "Note Added" at end of paper for details. V2: Includes significantly revised proof of Theorem 27. V3: Includes expanded explanation of some of the technical detail

A Dual-Fluorescent Composite of Graphene Oxide and Poly(3-Hexylthiophene) Enables the Ratiometric Detection of Amines

A composite prepared by grafting a conjugated polymer, poly(3-hexylthiophene) (P3HT), to the surface of graphene oxide was shown to result in a dual-fluorescent material with tunable photoluminescent properties. Capitalizing on these unique features, a new class of graphene-based sensors that enables the ratiometric fluorescence detection of amine-based pollutants was developed. Moreover, through a detailed spectroscopic study, the origin of the optical properties of the aforementioned composite was studied and was found to be due to electronic decoupling of the conjugated polymer from the GO. The methodology described herein effectively overcomes a long-standing challenge that has prevented graphene based composites from finding utility in sensing and related applications.Meng, Dongli, Shaojun Yang, Dianming Sun, Yi Zeng, Jinhua Sun, Yi Li, Shouke Yan, Yong Huang, Christopher W. Bielawski, and Jianxin Geng. "A dual-fluorescent composite of graphene oxide and poly (3-hexylthiophene) enables the ratiometric detection of amines." Chemical Science 5, no. 8 (Apr., 2014): 3130-3134.Chemistr

Back signaling by the Nrg-1 intracellular domain

Transmembrane isoforms of neuregulin-1 (Nrg-1), ligands for erbB receptors, include an extracellular domain with an EGF-like sequence and a highly conserved intracellular domain (ICD) of unknown function. In this paper, we demonstrate that transmembrane isoforms of Nrg-1 are bidirectional signaling molecules in neurons. The stimuli for Nrg-1 back signaling include binding of erbB receptor dimers to the extracellular domain of Nrg-1 and neuronal depolarization. These stimuli elicit proteolytic release and translocation of the ICD of Nrg-1 to the nucleus. Once in the nucleus, the Nrg-1 ICD represses expression of several regulators of apoptosis, resulting in decreased neuronal cell death in vitro. Thus, regulated proteolytic processing of Nrg-1 results in retrograde signaling that appears to mediate contact and activity-dependent survival of Nrg-1–expressing neurons

Exceptional high Seebeck Coefficient and Gas-Flow-Induced Voltage in Multilayer Graphene

Monolayer graphene shows Seebeck coefficient several times and gas-flow-induced voltage twenty times higher than that of bulk graphite. Here we find that the Seebeck coefficient of multilayer graphene increases monotonically with increasing layer and reaches its peak value at hexa-layer ~77% higher than for monolayer and then decreases, although the electric resistance decreases monotonically with increasing layer. The flow-induced voltage is significantly higher in 2, 4, 5, 6, 7 layered graphene than in 1, 3, 8 layered one, against the prevailing view that it should be proportional to Seebeck coefficient. These thickness effects are also in sharp contrast to that in continuous aluminum nanofilms.Comment: 5 figures,20pages,conferenc

Rank Reduction for the Local Consistency Problem

We address the problem of how simple a solution can be for a given quantum local consistency instance. More specifically, we investigate how small the rank of the global density operator can be if the local constraints are known to be compatible. We prove that any compatible local density operators can be satisfied by a low rank global density operator. Then we study both fermionic and bosonic versions of the N-representability problem as applications. After applying the channel-state duality, we prove that any compatible local channels can be obtained through a global quantum channel with small Kraus rank.Comment: 6 pages, 0 figures. To appear in J.Math.Phy

Core-Shell Structured Polyamide 66 Nanofibers with Enhanced Flame Retardancy

We report the preparation of polymer nanofibers with enhanced flame retardancy by coaxial electrospinning polyamide 66 (PA 66) and nanoscale graphene hybridized with red phosphorus (NG-RP). Transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed that the nanofibers contained a NG-RP-based core surrounded by a PA 66 shell. The flame-retardant characteristics of the nanofibers were investigated by thermal gravimetric analysis, micro combustion calorimetry, and a series of vertical flame tests. The encapsulation of the NG-RP not only enhanced the flame-retardant characteristics of the nanofibers, but also improved their mechanical properties while maintaining the color and luster of the polymer, making the resultant nanofibers appropriate for use in a wide range of applications