Real-time imaging of astrocyte response to quantum dots: in vivo screening model system for biocompatibility of nanoparticles

Astrocytes are the principle macroglial brain cells. They are activated by different stressors and brain injuries. Quantum dots (QDs) can cause oxidative stress. This study shows a real-time imaging of primary cortical cultures and assessment of QD-induced activation of astrocytes in the brains of transgenic mice with the luciferase gene driven by the murine astrocyte promoter. This approach may be widely applicable for assessing the astroglia/tissue response to nanoparticles in live animals.     

Characterization of Micro-Powders for the Fabrication of Compression Molded THz Lenses

We investigate different micro-powders that can be used as base materials for THz lenses fabricated by compression molding. For this application materials with a very weak THz absorbance and low dispersion are required. By measuring the THz absorption coefficient and refractive index of pellets pressed from the different micro-powders, we identify several materials that are well suited for the fabrication of compression molded THz lenses (CMLs). In addition, a considerable range of the refractive index is covered by the samples, which will allow for the fabrication of CMLs with different focal lengths for one and the same lens design.     

Dislocation creep controlled superplasticity in the high carbon steel 140NiCr16-6

Superplasticity in the alloyed high carbon-steel 140NiCr16-6 with phosphorus additions and a fine grained microdupiex structure – containing cementite in volume fractions of 22 % (Fe,Cr,Ni)₃C, particle size of about 1 μm and with a medium ferrite grain size of about 2 μm – has been investigated in the temperature regime of 550 to 675°C and in the strain rate range of 10^?5 to 5 · 10^?2 s^?1. Maximum strain rate exponents of m = 0,45 at 675°C with strain rates of the order of 10^?4 s^?1 have been determined. Maximum superplastic elongations of about 700 % were detected. At higher strain rates of 10^?3 s^?1 superplastic elongations of about 570 % were achieved. At relatively low test temperatures of 550°C elongations up to 230 % were recorded. The activation analysis in the temperature regime of 550 to 650°C show an activation energy for superplastic flow of 250 ± 20 kJ/mol. This is in agreement with the activation energy for lattice self diffusion of iron in α-iron. Above 650°C the activation energy decreases to 70 kJ/mol. This is due to a stress induced decrease in the eutectoid α-γ-transformation temperature from 685°C to somewhat lower temperatures during superplastic deformation. The superplastic deformability (m > 0.3) of this steel in a wide strain rate range at relatively low temperatures above 550°C allows near net shape forming of complex parts applying low flow stresses.     

Boosting Room‐Temperature Magneto‐Ionics in a Non‐Magnetic Oxide Semiconductor

Voltage control of magnetism through electric field‐induced oxygen motion (magneto‐ionics) could represent a significant breakthrough in the pursuit for new strategies to enhance energy efficiency in magnetically actuated devices. Boosting the induced changes in magnetization, magneto‐ionic rates and cyclability continue to be key challenges to turn magneto‐ionics into real applications. Here, it is demonstrated that room‐temperature magneto‐ionic effects in electrolyte‐gated paramagnetic Co₃O₄ films can be largely increased both in terms of generated magnetization (6 times larger) and speed (35 times faster) if the electric field is applied using an electrochemical capacitor configuration (utilizing an underlying conducting buffer layer) instead of placing the electric contacts at the side of the semiconductor (electric‐double‐layer transistor‐like configuration). This is due to the greater uniformity and strength of the electric field in the capacitor design. These results are appealing to widen the use of ion migration in technological applications such as neuromorphic computing or iontronics in general.     

Correction to: The influence of training level on manual fight in connection to performance,scan pattern,and task load

Cognition, Technology & Work - A correction to this paper has been published: https://doi.org/10.1007/s10111-021-00680-1     

ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.