Salmonella is a leading cause of foodborne outbreaks in Taiwan. On 27 April 2018, a salmonellosis outbreak among customers of a restaurant was reported to the Taiwan CDC. We investigated the outbreak to identify infection sources and prevent further transmission. We interviewed ill customers and their dining companions. We conducted a case-control study to identify foods associated with the illness. Case-patients were those who had diarrhoea within 72 h after eating at the restaurant during 16–27 April 2018. Specimens, food samples and environmental samples were collected and tested for enteric pathogens. Salmonella isolates were analysed with pulse-field gel electrophoresis and whole-genome sequencing. We inspected the restaurant sanitation and reviewed kitchen surveillance camera recordings. We identified 47 case-patients, including one decedent. Compared with 44 controls, case-patients were more likely to have had a French toast sandwich (OR: 102.4; 95% CI: 18.7–952.3). Salmonella Enteritidis isolates from 16 case-patients shared an indistinguishable genotype. Camera recordings revealed eggshell contamination, long holding time at room temperature and use of leftovers during implicated food preparation. Recommendations for restaurant egg-containing food preparation are to use pasteurised egg products and ensure a high enough cooking temperature and long enough cooking time to prevent Salmonella contamination.

The effects of boundaries such as grain boundaries and phase boundaries on low-field magnetoresistance (LFMR) have been investigated in single-phase lanthanum strontium manganates, in this case La0.7Sr0.3MnO3 (LSMO) and LSMO: zinc oxide (ZnO) nanocomposite thin films. In the pure LSMO films with similar grain size, it is found that the LFMR increases as the grain misorientation factor (β) increases. The LFMR in the nanocomposite films is greatly enhanced, as compared with single-phase films, due to the reduced grain size, and increased phase boundary (PB) and β effects. The composition study shows that the LFMR can be dramatically enhanced when the secondary phase content approaches the percolation threshold. The increased β and secondary phase concentration reduce the cross-section of electron conduction paths and favor the formation of the quasi-one-dimensional transport channels. Our results demonstrate that the reduction of cross-section of the electron conduction paths by tuning the grain orientation and secondary phase composition is necessary for enhancing LFMR effect.

In this article, we report the unique microstructural characteristics of YBa2Cu3O7-x (YBCO)/BaSnO3 (BSO) nanocomposite thin films on LaAlO3 (LAO) substrates. The BSO secondary phase grows as self-assembled vertically aligned nanopillars uniformly distributed in the superconducting YBCO matrix. Detailed microstructure and strain studies including x-ray diffraction, cross-section and plan-view transmission electron microscopy, and geometric phase analysis reveal that, as the BSO doping concentration varied from 2 mol% to 20 mol%, the nanopillar density increased from 0.26 × 1011/cm2 to 1.44 × 1011/cm2 while the diameter of the nanopillars remains relatively constant (7–8 nm in diameter). The strain state of the YBCO matrix is affected by both lateral and vertical lattice strains; while, the BSO lattice is strongly tuned by YBCO rather than the substrate. A high-density array of dislocations in the order of 1013/cm2 was observed along the vertical heterogeneous interfaces throughout the YBCO film thickness for all doping concentrations.