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Zusammenfassung Hintergrund Die akute Leberfunktionsstörung als akutes Leberversagen (ALV) oder akut-auf-chronisches Leberversagen (ACLV) ist ein intensivmedizinisches, interdisziplinär zu behandelndes Krankheitsbild mit einem hohen Letalitätsrisiko. Ziel Nomenklatur, Pathophysiologie, Prognose und mögliche Therapieoptionen des ALV und des ACLV sollen erläutert werden einschließlich der Möglichkeiten der extrakorporalen Leberersatztherapie an der Schwelle zur Lebertransplantation (LTx). Methode Narrative Übersicht mit selektiver Literaturrecherche und eigenen repräsentativen Fallbeispielen. Ergebnisse/Eckpunkte ALV und ACLV haben vielfältige Ursachen und eine hohe Letalität. Beim ALV kommt es auf die genaue Ermittlung der Ursache an, weil teilweise spezielle Therapiemöglichkeiten zur Verfügung stehen. Sowohl bei ALV und ACLV kann zum Überleben eine Lebertransplantation erforderlich sein, für ALV und ACLV existieren unterschiedliche Kriterien für Indikationsstellung und Transplantatallokation. Zur extrakorporalen Leberunterstützung haben sich 2 Verfahren etabliert (MARS [molecuar adsorbent recirculating system] und FPSA [fractionated plasma separation and adsorption] Prometheus®). Beide Verfahren können in der Lage sein, bei einem ALV oder einem ACLV die Überlebenswahrscheinlichkeit zu erhöhen, und sie werden in einzelnen Fällen zum Bridging zur LTx eingesetzt, außerdem in Einzelfällen zur primären Giftelimination, z. B. nach Amatoxiningestion. Beide Verfahren sind nicht als Dauertherapie geeignet. Schlussfolgerung Akutes Leberversagen und akut-auf-chronisches Leberversagen sind schwerwiegende Krankheitsbilder mit hohem Letalitätsrisiko. Betroffene Patienten sollten schnellstmöglich einer interdisziplinären Intensivtherapie in einem (tertiären) Zentrum zugeführt werden mit dem Ziel, die Krankheitsursache und mögliche Therapieoptionen hinsichtlich vorgehaltener extrakorporaler Leberunterstützungsverfahren und Lebertransplantation abzuklären.

In this article, we present our development of a virtual reality simulation of sailing on the Hōkūle‘a, a Polynesian double-hulled sailing canoe built in Hawai‘i in 1974, which completed its worldwide journey in 2017. The construction and sailing of this vessel is of significant importance to the Hawaiian cultural renaissance of the 1970s and 1980s; of particular relevance is Hawaiian wayfinding, the cultural practice of navigating across the open ocean to a destination without the use of maps or modern navigation instruments. By developing the simulation, we aimed to assist in the cultural preservation of the star navigation portion of Hawaiian wayfinding techniques, and to help to educate future generations of non-instrument navigators. The first implementation of Kilo Hōkū as a cultural heritage project in virtual reality was to test its viability as a tool for Modern Hawaiian wayfinders to use in classroom instruction, and its realism as an accurate reproduction of the Hōkūle‘a’s sailing experience. The reaction to the simulation from current practicing Modern Hawaiian wayfinders was positive, and indicates that further study is warranted in testing the efficacy of the simulation for teaching Hawaiian wayfinding to future navigators, as well as preserving and spreading knowledge of Hōkūle‘a and of Modern Hawaiian wayfinding beyond Hawai‘i.

This paper investigates the physical properties of 99.91% pure copper produced by Additive Manufacturing via selective electron beam melting (SEBM). Eddy current measurements and laser flash analyses are used to determine the electrical and the thermal conductivity. Electrical and thermal conductivity follow the Wiedemann-Franz law. The correlation of conductivities and porosity shows that 99.95 % dense components with nearly optimal conductivities (σ = 55.82 MS m–1 and λ = 400.1 W m–1 K–1) can be fabricated with SEBM. The small deviation from the theoretical maximum of copper (59.7 MS m–1) can be explained by the characteristics of the raw material and chemical impurities.

Novel monolithic structures with zeolitic [sodalite (SOD), Linde-Type A (LTA) and faujasite (FAU)-type] architectures having well-defined pores, cages and channels are successfully fabricated by selective electron beam melting (SEBM) using Ti–6Al–4V powder. The open porosities of the monoliths are 92.87% (SOD), 94.64% (LTA) and 95.67% (FAU), respectively. Although the porosity of the FAU monolith is relatively higher than the other two monoliths (SOD and LTA), but exhibits higher normalized pressure drop due to its inherent pore tortuosity (supercages interconnected by 12-ring channels in all three dimensions). This represents a significant step forward for the design and development of innovative structured supports and/or reactors with desired porosities and pressure drop characteristics.

Funded by the National Science Foundation, Polar-ICE partnered with the Monterey Bay Aquarium Research Institute’s EARTH program to offer a collaborative workshop for educators and polar scientists to develop lesson plans that integrate polar data into the classroom curriculum. In this article, we share one of the many lessons created in this workshop.

An experiment conducted with a megajoule class helical flux compression generator (HFCG), operating into a primarily inductive load, is described. The motivation behind the experiment was to benchmark the performance of the generator at higher currents and voltages than were tested in prior experiments. The intention was to push operation into a regime where flux loss was likely to become nonlinear, thereby gaining some insight into performance limitations of the design. Another goal was the desire to benchmark the suite of computational tools used to predict the performance of the design, especially in regimes of nonlinear flux loss. In the experiment, the HFCG was seeded with 105 kA (1.05 Wb), and produced 8.6 MA (0.28 Wb) into the load. This result differed significantly from computational models of the experiment, which predicted greater than 10 MA into the load. While more than one source of flux loss was observed in the waveforms, the dominant source of loss appears to be associated with joule heating and magnetic diffusion, which were found to have the most impact during the latter stages of HFCG operation. Details of the experiment design, setup and execution will be given. Analysis of the captured data, along with comparison of these data with model predictions and past experimental data, will be shown.