Dynamic current susceptibility as a probe of Majorana bound states in nanowire-based Josephson junctions

We theoretically study a Josephson junction based on a semiconducting nanowire subject to a time-dependent flux bias. We establish a general density matrix approach for the dynamical response of the Majorana junction and calculate the resulting flux-dependent susceptibility using both microscopic and effective low-energy descriptions for the nanowire. We find that the diagonal component of the susceptibility, associated with the dynamics of the Majorana states populations, dominates over the standard Kubo contribution for a wide range of experimentally relevant parameters. The diagonal term, thus far unexplored in the context of Majorana physics, allows to probe accurately the presence of Majorana bound states in the junction.Comment: 5 pages, 3 figures, 15 pages of supplemental materia

Alteration of superconductivity and radial breathing modes in suspended ropes of carbon nanotubes by organic polymer coatings

We have altered the superconductivity of a suspended rope of single walled carbon nanotubes, by coating it with organic polymers. Upon coating, the normal state resistance of the rope changes by less than 20%. But superconductivity, which on the bare rope shows up as a substantial resistance decrease below 300 mK, is gradually suppressed. We correlate this to the suppression of radial breathing modes, measured with raman spectroscopy on suspended single and double-walled carbon nanotubes. This points to the breathing phonon modes as being responsible for superconductivity in ropes of single walled carbon nanotubes

Problèmes d'adaptation du traitement antivitamine K dans les troubles du rythme supraventriculaires avant choc électrique externe (suivi sur un an dans le Service de cardiologie du Groupe hospitalier Sud Réunion)

BESANCON-BU Médecine pharmacie (250562102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Quantum Noise in Carbon Nanotubes as a Probe of Correlations in the Kondo Regime

International audienc

Superconductivity and normal state resistance of carbon nanotubes

International audienc

Superconductivity and normal state resistance of carbon nanotubes

International audienc

High third-generation cephalosporin resistant Enterobacteriaceae prevalence rate among neonatal infections in Dakar, Senegal

Abstract Background Neonatal infection constitutes one of Senegal’s most important public health problems, with a mortality rate of 41 deaths per 1,000 live births. Methods Between January 2007 and March 2008, 242 neonates with suspected infection were recruited at three neonatal intensive care units in three major tertiary care centers in Dakar, the capital of Senegal. Neonatal infections were confirmed by positive bacterial blood or cerebrospinal fluid culture. The microbiological pattern of neonatal infections and the antibiotic susceptibility of the isolates were characterized. In addition, the genetic basis for antibiotic resistance and the genetic background of third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae were studied. Results A bacteriological infection was confirmed in 36.4 % (88/242) of neonates: 22.7 % (30/132) during the early-onset and 52.7 % (58/110) during the late-onset periods (p > 0.20). Group B streptococci accounted for 6.8 % of the 88 collected bacterial isolates, while most of them were Enterobacteriaceae (n = 69, 78.4 %). Of these, 55/69 (79.7 %) were 3GC-R. The blaCTX-M-15 allele, the blaSHV and the blaTEM were highly prevalent (63.5, 65.4 and 53.8 %, respectively), usually associated with qnr genes (65.4 %). Clonally related strains of 3GC-R Klebsiella pneumoniae and 3GC-R Enterobacter cloacae, the two most commonly recovered 3GC-R Enterobacteriaceae (48/55), were detected at the three hospitals, underlining the role of cross-transmission in their spread. The overall case fatality rate was 18.6 %. Conclusions Measures should be taken to prevent nosocomial infections and the selection of resistant bacteria