TY - JOUR A1 - Brixner, Tobias A1 - Pawłowska, Monika A1 - Goetz, Sebastian A1 - Dreher, Christian A1 - Wurdack, Matthias A1 - Krauss, Enno A1 - Razinskas, Gary A1 - Geisler, Peter A1 - Hecht, Bert T1 - Shaping and spatiotemporal characterization of sub-10-fs pulses focused by a high-NA objective N2 - We describe a setup consisting of a 4 f pulse shaper and a microscope with a high-NA objective lens and discuss the spects most relevant for an undistorted spatiotemporal profile of the focused beam. We demonstrate shaper-assisted pulse compression in focus to a sub-10-fs duration using phase-resolved interferometric spectral modulation (PRISM). We introduce a nanostructure-based method for sub-diffraction spatiotemporal characterization of strongly focused pulses. The distortions caused by optical aberrations and space–time coupling from the shaper can be reduced by careful setup design and alignment to about 10 nm in space and 1 fs in time. KW - Interference microscopy KW - Scanning microscopy KW - Subwavelength structures KW - nanostructures KW - Pulse shaping KW - Ultrafast measurements Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111120 ER - TY - JOUR A1 - Rewitz, Christian A1 - Keitzl, Thomas A1 - Tuchscherer, Philip A1 - Goetz, Sebastian A1 - Geisler, Peter A1 - Razinskas, Gary A1 - Hecht, Bert A1 - Brixner, Tobias T1 - Spectral-interference microscopy for characterization of functional plasmonic elements JF - Optics Express N2 - Plasmonic modes supported by noble-metal nanostructures offer strong subwavelength electric-field confinement and promise the realization of nanometer-scale integrated optical circuits with well-defined functionality. In order to measure the spectral and spatial response functions of such plasmonic elements, we combine a confocal microscope setup with spectral interferometry detection. The setup, data acquisition, and data evaluation are discussed in detail by means of exemplary experiments involving propagating plasmons transmitted through silver nanowires. By considering and experimentally calibrating any setup-inherent signal delay with an accuracy of 1 fs, we are able to extract correct timing information of propagating plasmons. The method can be applied, e.g., to determine the dispersion and group velocity of propagating plasmons in nanostructures, and can be extended towards the investigation of nonlinear phenomena. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85922 UR - http://www.opticsinfobase.org/oe/fulltext.cfm?uri=oe-20-13-14632&id=238393 ER - TY - JOUR A1 - Hetzer, Benjamin A1 - Orth-Höller, Dorothea A1 - Würzner, Reinhard A1 - Kreidl, Peter A1 - Lackner, Michaela A1 - Müller, Thomas A1 - Knabl, Ludwig A1 - Geisler-Moroder, Daniel Rudolf A1 - Mellmann, Alexander A1 - Sesli, Özcan A1 - Holzknecht, Jeanett A1 - Noce, Damia A1 - Akarathum, Noppadon A1 - Chotinaruemol, Somporn A1 - Prelog, Martina A1 - Oberdorfer, Peninnah T1 - “Enhanced acquisition of antibiotic-resistant intestinal E. coli during the first year of life assessed in a prospective cohort study” JF - Antimicrobial Resistance & Infection Control N2 - Background Increasing bacterial resistance to antibiotics is a serious problem worldwide. We sought to record the acquisition of antibiotic-resistant Escherichia coli (E. coli) in healthy infants in Northern Thailand and investigated potential determinants. Methods Stool samples from 142 infants after birth, at ages 2wk, 2mo, 4 to 6mo, and 1y, and parent stool samples were screened for E. coli resistance to tetracycline, ampicillin, co-trimoxazole, and cefazoline by culture, and isolates were further investigated for multiresistance by disc diffusion method. Pulsed-field gel electrophoresis was performed to identify persistent and transmitted strains. Genetic comparison of resistant and transmitted strains was done by multilocus sequence typing (MLST) and strains were further investigated for extra- and intra-intestinal virulence factors by multiplex PCR. Results Forty-seven (33%) neonatal meconium samples contained resistant E. coli. Prevalence increased continuously: After 1y, resistance proportion (tetracycline 80%, ampicillin 72%, co-trimoxazole 66%, cefazoline 35%) almost matched those in parents. In 8 infants (6%), identical E. coli strains were found in at least 3 sampling time points (suggesting persistence). Transmission of resistant E. coli from parents to child was observed in only 8 families. MLST showed high diversity. We could not identify any virulence genes or factors associated with persistence, or transmission of resistant E. coli. Full-term, vaginal birth and birth in rural hospital were identified as risk factors for early childhood colonization with resistant E. coli. Conclusion One third of healthy Thai neonates harboured antibiotic-resistant E. coli in meconium. The proportion of resistant E. coli increased during the first year of life almost reaching the value in adults. We hypothesize that enhancement of infection control measures and cautious use of antibiotics may help to control further increase of resistance. KW - Escherichia coli KW - antibiotic resistance KW - multiresistance KW - transmission KW - persistence KW - children KW - neonates Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-320284 VL - 8 ER -