Showing papers by "M. Steinke published in 2022"
TL;DR: Using FTIR scanning spectroscopy in combination with an automated polymer identification approach, this paper showed that all five species of Arctic zooplankton investigated had ingested microplastics.
28 citations
TL;DR: Li et al. as discussed by the authors synthesized monodispersed LiYF4:Pr3+ nanocrystals having a size of 10 nm resulting in colorless clear stable colloidal dispersions and conducted an extensive optical characterization.
Abstract: Though Pr3+ doped LiYF4 (LiYF4:Pr3+) bulk crystals are a well-known laser gain material with several radiative transitions, their nanocrystal counterparts have not been investigated with regards to these. Through downsizing to the nanoscale, novel applications are expected, especially in composite photonic devices. For example, nanocrystals in stable colloidal form with narrow size distribution are highly desirable to reduce scattering in such composites. Herein, we synthesized monodispersed LiYF4:Pr3+ nanocrystals having a size of 10 nm resulting in colorless clear stable colloidal dispersions and conducted an extensive optical characterization for the first time. We observed unexpected yet intense emission with excited state lifetimes comparable to bulk crystals in the visible spectrum through excitation at 444 nm and 479 nm. In macroscopic bulk crystals, this emission is only exploitable through excitation of a different, subjacent energy level. A comprehensive comparison to the bulk crystals provides deeper insight into the excitation mechanism and performance of these nanocrystals. The presented results pave the way for developing application-oriented LiYF4:Pr3+ nanocrystals as emitters with tailored properties for quantum optics or biomedical applications.
2 citations
TL;DR: In this article , negative emotionality (NE) was evaluated as a candidate mechanism linking prenatal maternal affective symptoms and offspring internalizing problems during the preschool/early school age period.
Abstract: Negative emotionality (NE) was evaluated as a candidate mechanism linking prenatal maternal affective symptoms and offspring internalizing problems during the preschool/early school age period. The participants were 335 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment project. A Confirmatory Bifactor Analysis (CFA) based on self-report measures of prenatal depression and pregnancy-specific anxiety generated a general factor representing overlapping symptoms of prenatal maternal psychopathology and four distinct symptom factors representing pregnancy-specific anxiety, negative affect, anhedonia and somatization. NE was rated by the mother at 18 and 36 months. CFA based on measures of father, mother, child-rated measures and a semistructured interview generated a general internalizing factor representing overlapping symptoms of child internalizing psychopathology accounting for the unique contribution of each informant. Path analyses revealed significant relationships among the general maternal affective psychopathology, the pregnancy- specific anxiety, and the child internalizing factors. Child NE mediated only the relationship between pregnancy-specific anxiety and the child internalizing factors. We highlighted the conditions in which prenatal maternal affective symptoms predicts child internalizing problems emerging early in development, including consideration of different mechanistic pathways for different maternal prenatal symptom presentations and child temperament.
2 citations
TL;DR: In this paper , up-conversion-nanocrystals exhibit a temperature dependent emission and were attached to a fiber facet and applied as a nanothermometer in an electrolysis cell.
Abstract: Temperature measurements inside electrolysis cells pose a challenge for conventional sensors. Since up-conversion-nanocrystals exhibit a temperature dependent emission, we attached such nanocrystals to a fiber facet and applied it as nanothermometer in an electrolysis cell. This approach will yield new insights into the performance of these cells.
01 May 2022
TL;DR: In this article , a monolithic, single-frequency EYDFA at 1556 nm with polarization-maintaining fibers and advanced cooling concept was presented, long-term tested at 50 W output power with low amplified spontaneous emission levels and no stimulated Brillouin scattering.
Abstract: We present a monolithic, single-frequency EYDFA at 1556 nm with polarizationmaintaining fibers and advanced cooling concept. The amplifier was long-term tested at 50 W output power with low amplified spontaneous emission levels and no stimulated Brillouin scattering.
30 May 2022
TL;DR: In this paper , a 3D printed phase mask was applied to the fiber bundle of an endoscopy, which was then used for 3D imaging of brain and cochlea.
Abstract: Endoscopes with 3D imaging have been known for some time. Additional information about the depth allows further statements during the examination and better visualisation. However, the measuring heads of such endoscopes are bulky, since they must accommodate optics that enable axial scanning. Hence, the field of application remains very limited. We present an endoscope without optics on the distal end and a significantly smaller measuring head in the sub-millimetre range. This enables endoscope technology to be used in new areas of surgery, such as in brain or cochlea. Conventional endoscopes are too large for these regions. A static phase correction has been demonstrated to be sufficient to maintain phase information. Hence, programmable optics like spatial light modulators are no longer needed. Therefore, we applied 3D printed phase masks using 2-photon polymerisation. This allows a robust and cost-efficient system to be realised. In addition to the process of printing phase correction DOEs, we also present a new setup which allows the sample in front of the endoscope head to be imaged through the fibre bundle directly to a camera sensor. No raster scan is required like in past approaches. Hence, an image can be generated in a single shot without further computational reconstruction.