@article{BrixnerPawłowskaGoetzetal.2014, author = {Brixner, Tobias and Pawłowska, Monika and Goetz, Sebastian and Dreher, Christian and Wurdack, Matthias and Krauss, Enno and Razinskas, Gary and Geisler, Peter and Hecht, Bert}, title = {Shaping and spatiotemporal characterization of sub-10-fs pulses focused by a high-NA objective}, doi = {10.1364/OE.22.031496}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111120}, year = {2014}, abstract = {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.}, language = {en} } @article{RewitzKeitzlTuchschereretal.2012, author = {Rewitz, Christian and Keitzl, Thomas and Tuchscherer, Philip and Goetz, Sebastian and Geisler, Peter and Razinskas, Gary and Hecht, Bert and Brixner, Tobias}, title = {Spectral-interference microscopy for characterization of functional plasmonic elements}, series = {Optics Express}, journal = {Optics Express}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85922}, year = {2012}, abstract = {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.}, language = {en} } @article{HetzerOrthHoellerWuerzneretal.2019, author = {Hetzer, Benjamin and Orth-H{\"o}ller, Dorothea and W{\"u}rzner, Reinhard and Kreidl, Peter and Lackner, Michaela and M{\"u}ller, Thomas and Knabl, Ludwig and Geisler-Moroder, Daniel Rudolf and Mellmann, Alexander and Sesli, {\"O}zcan and Holzknecht, Jeanett and Noce, Damia and Akarathum, Noppadon and Chotinaruemol, Somporn and Prelog, Martina and Oberdorfer, Peninnah}, title = {"Enhanced acquisition of antibiotic-resistant intestinal E. coli during the first year of life assessed in a prospective cohort study"}, series = {Antimicrobial Resistance \& Infection Control}, volume = {8}, journal = {Antimicrobial Resistance \& Infection Control}, doi = {10.1186/s13756-019-0522-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-320284}, year = {2019}, abstract = {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.}, language = {en} }