The more the better: on the formation of single-phase high entropy alloy nanoparticles as catalysts for the oxygen reduction reaction.

High entropy alloys (HEAs) are an important new material class with significant application potential in catalysis and electrocatalysis. The entropy-driven formation of HEA materials requires high temperatures and controlled cooling rates. However, catalysts in general also require highly dispersed materials, i.e., nanoparticles. Only then a favorable utilization of the expensive raw materials can be achieved. Several recently reported HEA nanoparticle synthesis strategies, therefore, avoid the high-temperature regime to prevent particle growth. In our work, we investigate a system of five noble metal single-source precursors with superior catalytic activity for the oxygen reduction reaction. Combining in situ X-ray powder diffraction with multi-edge X-ray absorption spectroscopy, we address the fundamental question of how single-phase HEA nanoparticles can form at low temperatures. It is demonstrated that the formation of HEA nanoparticles is governed by stochastic principles and the inhibition of precursor mobility during the formation process favors the formation of a single phase. The proposed formation principle is supported by simulations of the nanoparticle formation in a randomized process, rationalizing the experimentally found differences between two-element and multi-element metal precursor mixtures

Optimierung der Risiko- und Krisenkommunikation von Regierungen, Behörden und Organisationen der Gesundheitssicherung – Herausforderungen in lang anhaltenden Krisen am Beispiel der COVID-19-Pandemie [Optimisation of risk and crisis communication of governments, authorities and public health institutions—challenges in long-lasting crises illustrated by the COVID-19 pandemic]

Die COVID-19-Pandemie illustriert die besondere Bedeutung von Risiko- und Krisenkommunikation. Behörden und Politik stehen vor der Herausforderung, in einer dynamischen Lage mit einer Vielzahl von Daten umzugehen, diese zu überprüfen und zielgruppengerecht zu kommunizieren. Verständliche und eindeutige Informationen zu Risiken und Handlungsoptionen tragen maßgeblich zu einer Steigerung der objektiven und subjektiven Sicherheit der Bevölkerung bei. Es besteht daher ein großer Bedarf, die Erfahrungen aus der Pandemie in die Optimierung der Risiko- und Krisenkommunikation einfließen zu lassen. Die Digitalisierung ermöglicht multimodale Arrangements – also die Kombination aus Text, Abbildungen, Grafik, Icons und z. T. Bewegtbilder, Animationen und Ton. Diese spielen auch in der digitalen Risiko- und Krisenkommunikation eine zunehmend wichtigere Rolle. Von Interesse ist, inwiefern das kommunikative Zusammenspiel von Behörden, Medien und weiteren Öffentlichkeitsakteur/-innen in Vorbereitung auf und zur Bewältigung von Krisen angesichts einer komplexen Öffentlichkeit mit Hilfe zielgruppenspezifischer Kommunikation verbessert und wie Rechtssicherheit für die behördliche und mediale Praxis gewährleistet werden kann. Dementsprechend verfolgt der Beitrag 3 Ziele: 1. Er beschreibt die Herausforderungen, vor denen Behörden und mediale Akteur/-innen in der Pandemiekommunikation stehen. 2. Er zeigt, welche Rolle multimodale Arrangements spielen und welcher Forschungsperspektiven es bedarf, um die Komplexität des kommunikativen Krisenhandelns im föderalen System zu erfassen. 3. Er begründet, wie ein interdisziplinärer Forschungsverbund aus Medien‑, Kommunikations- und Rechtswissenschaft Erkenntnisse zum evidenzbasierten Einsatz multimodaler Kommunikation gewinnen kann

Gα_i Proteins are Indispensable for Hearing

Background/Aims: From invertebrates to mammals, Gαi proteins act together with their common binding partner Gpsm2 to govern cell polarization and planar organization in virtually any polarized cell. Recently, we demonstrated that Gαi3-deficiency in pre-hearing murine cochleae pointed to a role of Gαi3 for asymmetric migration of the kinocilium as well as the orientation and shape of the stereociliary (“hair”) bundle, a requirement for the progression of mature hearing. We found that the lack of Gαi3 impairs stereociliary elongation and hair bundle shape in high-frequency cochlear regions, linked to elevated hearing thresholds for high-frequency sound. How these morphological defects translate into hearing phenotypes is not clear. Methods: Here, we studied global and conditional Gnai3 and Gnai2 mouse mutants deficient for either one or both Gαi proteins. Comparative analyses of global versus Foxg1-driven conditional mutants that mainly delete in the inner ear and telencephalon in combination with functional tests were applied to dissect essential and redundant functions of different Gαi isoforms and to assign specific defects to outer or inner hair cells, the auditory nerve, satellite cells or central auditory neurons. Results: Here we report that lack of Gαi3 but not of the ubiquitously expressed Gαi2 elevates hearing threshold, accompanied by impaired hair bundle elongation and shape in high-frequency cochlear regions. During the crucial reprogramming of the immature inner hair cell (IHC) synapse into a functional sensory synapse of the mature IHC deficiency for Gαi2 or Gαi3 had no impact. In contrast, double-deficiency for Gαi2 and Gαi3 isoforms results in abnormalities along the entire tonotopic axis including profound deafness associated with stereocilia defects. In these mice, postnatal IHC synapse maturation is also impaired. In addition, the analysis of conditional versus global Gαi3-deficient mice revealed that the amplitude of ABR wave IV was disproportionally elevated in comparison to ABR wave I indicating that Gαi3 is selectively involved in generation of neural gain during auditory processing. Conclusion: We propose a so far unrecognized complexity of isoform-specific and overlapping Gαi protein functions particular during final differentiation processes

Seawater carbonate chemistry and the nutritional quality of the commercially-harvested turbinid snail Turbo militaris

Rising levels of atmospheric carbon dioxide are driving ocean warming and acidification. This could cause stress resulting in decreases in nutritional quality of marine species for human consumption, if environmental changes go beyond the optimal range for harvested species. To evaluate this, we used ambient and near-future elevated temperatures and pCO2 to assess impacts on the proximate nutritional composition (moisture, ash, protein, and lipids), fatty acids and trace elements of the foot tissue of Turbo militaris, a commercially harvested marine snail from south-eastern Australia. In a fully orthogonal design, the snails were exposed to ambient seawater conditions (22 ± 0.2 °C, pH 8.13 ± 0.01–450 μatm pCO2), ocean warming (25 ± 0.05 °C), pCO2 ocean acidification (pH 7.85 ± 0.02, ∼880 μatm pCO2) or a combination of both in controlled flow-through seawater mesocosms for 38 days. Moisture, ash, protein and total lipid content of the foot tissue in the turban snails was unaffected by ocean warming or acidification. However, ocean warming caused a reduction in healthful polyunsaturated fatty acids (PUFA) relative to saturated fatty acids (SFA). Under future warming and acidification conditions, there was a significant 3–5% decrease in n–3 fatty acids, which contributed to a decrease in the n–3/n–6 fatty acid ratio. The decrease in n–3 PUFAs, particularly Eicopentanoic acid (EPA), is a major negative outcome from ocean warming, because higher n–3/n–6 ratios in seafood are desirable for human health. Furthermore, ocean warming was found to increase levels of zinc in the tissues. Calcium, iron, macroelements, microelements and the composition of toxic elements did not appear to be affected by ocean climate change. Overall, the major impact from ocean climate change on seafood quality is likely to be a decrease in healthy polyunsaturated fatty acids at higher temperatures

Plasmid-mediated gene transfer of Cas9 induces vector-related but not SpCas9-related immune responses in human retinal pigment epithelial cells

The clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) system represents a powerful gene-editing tool and could enable treatment of blinding diseases of the retina. As a peptide of bacterial origin, we investigated the immunogenic potential of Cas9 in models of retinal immunocompetent cells: human microglia (IMhu) and ARPE-19 cells. Transfection with Streptococcus pyogenes-Cas9 expression plasmids (SpCas9 plasmid) induced Cas9 protein expression in both cell lines. However, only ARPE-19 cells, not IMhu cells, responded with pro-inflammatory immune responses as evidenced by the upregulation of IL-8, IL-6, and the cellular activation markers HLA-ABC and CD54 (ICAM). These pro-inflammatory responses were also induced through transfection with equally sized non-coding control plasmids. Moreover, viability rates of ARPE-19 cells were reduced after transfection with both the SpCas9 plasmids and the control plasmids. Although these results demonstrate cell type-specific responses to the DNA plasmid vector, they show no evidence of an immunogenic effect due to the presence of Cas9 in models of human retinal pigment epithelial and microglia cells. These findings add another layer of confidence in the immunological safety of potential future Cas9-mediated retinal gene therapies