Innovative mid-infrared detector concepts

Gas sensing is a key technology with applications in various industrial, medical and environmental areas. Optical detection mechanisms allow for a highly selective, contactless and fast detection. For this purpose, rotational-vibrational absorption bands within the mid infrared (MIR) spectral region are exploited and probed with appropriate light sources. During the past years, the development of novel laser concepts such as interband cascade lasers (ICLs) and quantum cascade lasers (QCLs) has driven a continuous optimization of MIR laser sources. On the other hand side, there has been relatively little progress on detectors in this wavelength range. Here, we study two novel and promising GaSb-based detector concepts: Interband cascade detectors (ICD) and resonant tunneling diode (RTD) photodetectors. ICDs are a promising approach towards highly sensitive room temperature detection of MIR radiation. They make use of the cascading scheme that is enabled by the broken gap alignment of the two binaries GaSb and InAs. The interband transition in GaSb/InAs-superlattices (SL) allows for normal incidence detection. The cut-off wavelength, which determines the low energy detection limit, can be engineered via the SL period. RTD photodetectors act as low noise and high speed amplifiers of small optically generated electrical signals. In contrast to avalanche photodiodes, where the gain originates from multiplication due to impact ionization, in RTD photodetectors a large tunneling current is modulated via Coulomb interaction by the presence of photogenerated minority charge carriers. For both detector concepts, first devices operational at room temperature have been realized.Publisher PD

Very Small Embryonic-Like Stem Cells Purified from Umbilical Cord Blood Lack Stem Cell Characteristics

Very small embryonic-like (VSEL) cells have been described as putatively pluripotent stem cells present in murine bone marrow and human umbilical cord blood (hUCB) and as such are of high potential interest for regenerative medicine. However, there remain some questions concerning the precise identity and properties of VSEL cells, particularly those derived from hUCB. For this reason, we have carried out an extensive characterisation of purified populations of VSEL cells from a large number of UCB samples. Consistent with a previous report, we find that VSEL cells are CXCR4+, have a high density, are indeed significantly smaller than HSC and have an extremely high nuclear/cytoplasmic ratio. Their nucleoplasm is unstructured and stains strongly with Hoechst 33342. A comprehensive FACS screen for surface markers characteristic of embryonic, mesenchymal, neuronal or hematopoietic stem cells revealed negligible expression on VSEL cells. These cells failed to expand in vitro under a wide range of culture conditions known to support embryonic or adult stem cell types and a microarray analysis revealed the transcriptional profile of VSEL cells to be clearly distinct both from well-defined populations of pluripotent and adult stem cells and from the mature hematopoietic lineages. Finally, we detected an aneuploid karyotype in the majority of purified VSEL cells by fluorescence in situ hybridisation. These data support neither an embryonic nor an adult stem cell like phenotype, suggesting rather that hUCB VSEL cells are an aberrant and inactive population that is not comparable to murine VSEL cells

Supercapacitors (electrochemical capacitors)

International audienceRapid development of the technologies based on electric energy in the last decades have stimulated intensive research on efficient power sources. Electrochemical energy conversion and storage systems are based on Faradaic reactions (charge transfer) and electrostatic attraction of ions at the electrode/electrolyte interface. The latter might be an interesting solution for applications requiring moderate energy density, high power rates, and long cycle life. Electrochemical capacitors (ECs) store the charge in a physical manner, hence, their energy density is moderate. At the same time, the lack of electrochemical reactions ensures very high power and long cycle life compared to batteries. Activated carbons with their versatile properties (like specific surface area, well-developed and suitable porosity, heteroatoms in the graphene matrix) are the most popular materials in EC application. This chapter provides a comprehensive overview of the carbon-based materials recently developed, with special attention devoted to those obtained by biomass carbonization and activation. Electrochemical properties demonstrated by such carbons are discussed in respect to their physicochemical characteristic

Das CRISPR/Cas9-System: Disruption in der Biotechnologie?

Innovation und Technologie sind für Mitbestimmungsakteure wichtige Themen. Sie brauchen wissenschaftliche Expertise, um Innovationsprozesse und -politiken und Technologiepolitiken mitzugestalten. Mit CRISPR/Cas9 steht eine neue molekulargenetische Methode zur Verfügung, die es ermöglicht, Eingriffe im Erbgut von Organismen schneller und kostengünstiger durchzuführen als je zuvor. Hier wird das Thema CRISPR/Cas9 im Kontext von Anwendungsmöglichkeiten, rechtlichen Rahmenbedingungen, sozio-ökonomischer Bedeutung und gesellschaftlicher und ethischer Diskurse für Arbeitnehmerakteure aufbereitet

Arbeiten in der zukünftig vernetzten Klinik

Innovative Technologien sind für Mitbestimmungsakteure ein wichtiges Gestaltungsfeld, zu denen sie wissenschaftliche Expertise benötigen. Das Gesundheitswesen steht gegenwärtig vor neuen Herausforderungen durch Digitalisierung, Vernetzung und die Nutzung von Künstlicher Intelligenz. Das Working Paper behandelt das Thema Arbeiten in der zukünftig vernetzten Klinik im Kontext von möglichen Anwendungsfeldern, fördernder und hemmender Faktoren, sowie der sozio-ökonomischen Bedeutung für Beschäftigte und Arbeitgeber in der Branche. Außerdem liefert sie Denkanstöße zu einer frühzeitigen öffentliche Diskussion