Danube University Krems 2 articles published in JoVE Engineering Evaluating Usability Aspects of a Mixed Reality Solution for Immersive Analytics in Industry 4.0 Scenarios Burkhard Hoppenstedt1, Thomas Probst2, Manfred Reichert1, Winfried Schlee3, Klaus Kammerer1, Myra Spiliopoulou4, Johannes Schobel1, Michael Winter1, Anna Felnhofer5, Oswald D. Kothgassner6, Rüdiger Pryss7 1Institute of Databases and Information Systems, Ulm University, 2Department for Psychotherapy and Biopsychosocial Health, Danube University Krems, 3Department of Psychiatry and Psychotherapy, University of Regensburg, 4Faculty of Computer Science, Otto von Guericke University Magdeburg, 5Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, 6Department of Child and Adolescent Psychiatry, Medical University of Vienna, 7Institute of Clinical Epidemiology and Biometry, University of Würzburg This protocol delineates the technical setting of a developed mixed reality application that is used for immersive analytics. Based on this, measures are presented, which were used in a study to gain insights into usability aspects of the developed technical solution. Medicine Biotribological Testing and Analysis of Articular Cartilage Sliding against Metal for Implants Christoph Stotter1,2, Christoph Bauer1, Bojana Simlinger3, Manel Rodriguez Ripoll3, Friedrich Franek3, Thomas Klestil1,2, Stefan Nehrer1 1Faculty of Health and Medicine, Department for Health Sciences, Medicine and Research, Center for Regenerative Medicine, Danube University Krems, 2Department of Orthopedics and Traumatology, LK Baden-Mödling-Hainburg, 3AC2T research GmbH This protocol describes the preparation, biotribological testing, and analysis of osteochondral cylinders sliding against metal implant material. Outcome measures included in this protocol are metabolic activity, gene expression and histology.