Emergence, Evolution and Scaling of Online Social Networks

This work was partially supported by AFOSR under Grant No. FA9550-10-1-0083, NSF under Grant No. CDI-1026710, NSF of China under Grants Nos. 61473060 and 11275003, and NBRPC under Grant No. 2010CB731403. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Exceptional entanglement in non-Hermitian fermionic models

Exotic singular objects, known as exceptional points, are ubiquitous in non-Hermitian physics. They might be spectral singularities in energy bands that produce anomalous effects and defectiveness. The quantum entanglement of a generic non-Hermitian model with two different types of spectral exceptional points (SEPs) is systematically investigated in this paper. We discovered a relationship between non-unitary conformal field theories and the $k$-linear-type SEPs, which is typically associated with $\mathcal{PT}$-symmetry or pesdo-Hermicity spontaneous breaking. The underlying association between $k$-square-root-type SEPs, which arise concurrently with real (imaginary) gap closing in the complex spectrum, mimicking first-order-phase-transition criticalities, and complex conformal field theories (cCFTs) is addressed through the calculation of complex central charges. From the entanglement spectrum, zero-energy exceptional modes are found to be distinct from normal zero modes or topological boundary modes. Finally, we include a brief discussion of analogous non-Hermitian quantum spin models and endeavor to establish an intuitive understanding of exceptional points through the spin picture in various scenarios

Prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis in female outpatients, 2009–2013

PurposeThe aim of this study was to estimate the prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis among female outpatients treated for genital infection at a Chinese hospital from January 1, 2009 to December 31, 2013.MethodsSamples from 6051 female outpatients were analyzed using Mycoplasma Identification and Antimicrobial Susceptibility Testing (ID/AST).ResultsThe overall prevalence of U. urealyticum was higher than the prevalence of single M. hominis infection (31.2% vs 0.7%) and coinfections (31.2% vs. 1.9%). The percentage of U. urealyticum and/or M. hominis detected in the 30–39 year age group was greater than in the other age groups. More than 94.6% of the U. urealyticum isolates, 100% of the M. hominis isolates, and 84.3% of the isolates from coinfections were susceptible to doxycycline, minocycline, and tetracycline. More than 69.2% of the U. urealyticum isolates were susceptible to azithromycin, erythromycin, clarithromycin, and roxithromycin, but > 95.6% of the M. hominis isolates and 89.6% of the isolates from coinfections were resistant to these antibiotics. Acetylspiramycin, sparfloxacin, levofloxacin, ciprofloxacin, and ofloxacin were inactive against more than one-half of the isolates. More than 75.6% of the M. hominis isolates were susceptible to spectinomycin, but > 87.1% of the U. urealyticum and 93.3% of the coinfection isolates were resistant to this antibiotic. Isolates from three coinfections were completely resistant to the 14 antibiotics.ConclusionThe determination of antimicrobial susceptibility of these mycoplasma species is often crucial for optimal antimicrobial therapy of infected outpatients

N′-(2-Chloro­benzyl­idene)-4-methyl­benzohydrazide

In the title compound, C15H13ClN2O, the mol­ecule displays a trans conformation with respect to the C=N bond. The two aromatic rings form a dihedral angle of 12.0 (3)°. In the crystal, mol­ecules are connected via N—H⋯O hydrogen bonds into chains propagating along the c-axis direction