No abstract

We conducted a retrospective study on non-typhoidal Salmonella isolates from patients with diarrhoea in Shanghai, China, 2006-2010. A total of 1484 isolates of 70 Salmonella serovars were recovered from about 18 000 stool specimens. Serovars Enteritidis and Typhimurium were the most prevalent with isolation rates of 27.6% and 25.5%, respectively. The majority (1151, 77.6%) of the isolates were resistant to at least one antimicrobial, and 598 (40.3%) to more than three antimicrobials. Approximately half (50.9%) of the isolates were resistant to nalidixic acid and other resistance rates were sulfisoxazole (47.9%), streptomycin (37.6%), ampicillin (31.3%) and tetracycline (30.5%). Co-resistance to fluoroquinolones and the third- and fourth-generation cephalosporins was also identified.

A new simple mechanism due to cold electron flow to produce strong magnetic field is proposed. A 600-T strong magnetic field is generated in the free space at the laser intensity of 5.7 × 10 15 ⋅ −2 . Theoretical analysis indicates that the magnetic field strength is proportional to laser intensity. Such a strong magnetic field offers a new experimental test bed to study laser-plasma physics, in particular, fast-ignition laser fusion research and laboratory astrophysics.

Laboratory experiments have been carried out to model the magnetic reconnection process in a solar flare with powerful lasers. Relativistic electrons with energy up to MeV are detected along the magnetic separatrices bounding the reconnection outflow, which exhibit a kappa-like distribution with an effective temperature of ∼10 9 K. The acceleration of non-thermal electrons is found more efficient in the case with a guide magnetic field (a component of magnetic field along the reconnection-induced electric field) than that in the case without a guide field. Hardening of the spectrum at energies ≥ 500 keV is observed in both cases, which remarkably resembles the hardennings of hard X-ray and γ-ray spectra observed in many solar flares. This supports a recent proposal that the hardening in the hard X-ray and γ-ray emissions of solar flares is due to a hardening of the source-electron spectrum. We also performed numerical simulations that help examine behaviors of electrons in the reconnection process with the electromagnetic field configurations occurring in the experiments. Trajectories of non-thermal electrons observed in the experiments were well duplicated in the simulations. Our numerical simulations generally reproduce the electron energy spectrum as well, except the hardening of the electron spectrum. This suggests that other mechanisms such as shock and/or turbulence may play an important role in productions of the observed energetic electron.

(a) Pentobarbital and ketamine modified cortical electrical activity in a different manner as a function of age; (b) the modification of electroencephalogram relative power with anaesthesia was identical in young and aged rats but quantitatively more marked in aged rats. These findings will be useful in designing experiments that assess pathological changes in the central nervous system during ageing.