Optical Nanoantennas for Multiband Surface-Enhanced Infrared and Raman Spectroscopy

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Optical properties and oxidation resistance of different transition metals for soft X-ray and EUV applications

The results of a comparative study of Ru-, Mo-, Nb- and Pd- coatings designed for grazing angle applications in the soft X-ray and extreme ultraviolet (EUV) spectrum are presented. Optical properties and temporal stability of coatings were investigated using EUV reflectometry at 13.5 nm and grazing incidence X-ray reflectometry (GIXR) with Cu-Kα radiation. Nb- and Mo-coatings showed a strong inclination to surface oxidation at ambient atmosphere leading to reflectivity losses. The Pd coating as a noble transition metal showed the highest oxidation resistance over a period of one year. The best reflective properties at 13.5 nm were achieved by Ru coatings. GIXR simulation results of the time dependent surface oxidation were used to predict the reflective properties of the studied coatings following four months of storage in an ambient atmosphere for a wide spectral range (5.0 nm–40.0 nm)

Interface characterization in B-based multilayer mirrors for next generation lithography

The interfaces in La/B4C and LaN/B4C multilayer mirrors designed for near normal incidence reflection of 6.x nm EUV light were investigated by grazing incidence X-ray reflectometry, high-resolution transmission electron microscopy and EUV reflectometry. The thickness and roughness asymmetries of the different interfaces in both studied systems have been identified. A development of interface roughness with an increasing number of bilayers was found by different investigation methods. For near normal incidence, R = 51.1% @ λ = 6.65 nm could be reached with our La/B4C multilayer mirrors, whereas R = 58.1% was achieved with LaN/B4C multilayers at the same wavelength

Exploring dose–response variability and relative severity assessment in STZ-induced diabetes male NSG mice

Abstract NSG mice are among the most immunodeficient mouse model being used in various scientific branches. In diabetelogical research diabetic NSG mice are an important asset as a xenotransplantation model for human pancreatic islets or pluripotent stem cell-derived islets. The treatment with the beta cell toxin streptozotocin is the standard procedure for triggering a chemically induced diabetes. Surprisingly, little data has been published about the reproducibility, stress and animal suffering in these NSG mice during diabetes induction. The 3R rules, however, are a constant reminder that existing methods can be further refined to minimize suffering. In this pilot study the dose–response relationship of STZ in male NSG mice was investigated and additionally animal suffering was charted by applying the novel ‘Relative Severity Assessment’ algorithm. By this we successfully explored an STZ dose that reliably induced diabetes while reduced stress and pain to the animals to a minimum using evidence-based and objective parameters rather than criteria that might be influenced by human bias

Influence of the ZnO:Al dispersion on the performance of ZnO:Al/Ag/ZnO:Al transparent electrodes

Highly transparent and conductive Al-doped ZnO/Ag/Al-doped ZnO (AZO/Ag/AZO) multilayers were prepared by industrial inline DC magnetron sputtering on glass substrates at room temperature. With optimized film thicknesses of 37 nm/10 nm/37 nm, an optimized low sheet resistance of only 6 Ω/sq. and high transmittances of T550 = 87.4% at 550 nm and T400–800 = 79.9% in the spectral range between 400 nm and 800 nm were reached. Furthermore, an increase of the AZO/Ag/AZO-performance was achieved when a small amount of oxygen was added to the process gas during the AZO deposition which was found to be because of a beneficial adjustment of the AZO dispersion. In this way, owing to both a decreased extinction coefficient as well as a higher refractive index of the AZO film, the maximum transmittance of the AZO/Ag/AZO three-layer structure is further increased (T550 = 89.0%) and the bandwidth of the transmittance range is broadened (T400–800 = 83.3%). With the adaption of the AZO dispersion a very high Figure-of-Merit (Haacke) Φ400–800 = 26.2 mΩ− 1 and Φ550 = 52.9 mΩ− 1 was achieved by industrial inline DC magnetron sputtering process

Chemically defined and xenogeneic-free differentiation of human pluripotent stem cells into definitive endoderm in 3D culture

Abstract In vitro differentiation of human pluripotent stem cells (hPSCs) into definitive endoderm (DE) represents a key step towards somatic cells of lung, liver and pancreas. For future clinical applications, mass production of differentiated cells at chemically defined conditions and free of xenogeneic substances is envisioned. In this study we adapted our previously published two-dimensional (2D) DE induction protocol to three-dimensional (3D) static suspension culture in the absence of the xenogeneic extracellular matrix Matrigel. Next, fetal calf serum and bovine serum albumin present in the standard medium were replaced by a custom-made and xeno-free B-27. This yielded in a chemically defined and xenogeneic-free 3D culture protocol for differentiation of hPSCs into DE at efficiencies similar to standard 2D conditions. This novel protocol successfully worked with different hPSC lines including hESCs and hiPSCs maintained in two different stem cell media prior to differentiation. DE cells obtained by our novel BSA-free 3D protocol could be further differentiated into PDX1- or NKX6.1-expressing pancreatic progenitor cells. Notably, upon DE differentiation, we also identified a CXCR4+/NCAM+/EpCAMlow cell population with reduced DE marker gene expression. These CXCR4+/NCAM+/EpCAMlow cells emerge as a result of Wnt/beta-catenin hyperactivation via elevated CHIR-99021 concentrations and likely represent misspecified DE