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Die unterschiedlichen Studien zum Bau von Musikinstrumenten-Prototypen mittels Additiver Fertigung zeigen deutlich die Vorteile der Designfreiheit. Zur industriellen Implementierung fehlen allerdings noch immer die Ansätze.

Im Rahmen des Modellprogrammes zur besseren Versorgung chronisch Kranker förderte das Bundesgesundheitsministerium (BMG) seit 1992 schwerpunktmäßig den Aufbau von Rheumazentren an 21 Orten der Bundesrepublik. Ziel war neben dem Aufbau formaler Strukturen die Verbesserung der Versorgungsqualität durch Koordination und Kooperation vorhandener Einrichtungen.

We provide an overview of recent articles which describe new thinking regarding HLA-B27-associated reactive arthritis (ReA), including those additional infection-related arthritides triggered by microbes that often are grouped under the term ReA.With the advent and continuation of the pandemic, an increasing number of cases and case series of post-COVID-19 arthritis have been reported and classified as ReA. Further, arthritis after COVID-19 vaccination is a new entity included within the spectrum of ReA. New causative microorganisms identified in case reports include Clostridium difficile, Mycoplasma pneumoniae, Giardia lamblia, Leptospira , and babesiosis. SARS-CoV-2 is emerging as a significant etiologic agent for apparent ReA.It is now clear that comprehensive clinical and laboratory investigations, synovial fluid analyses, and close follow-up of patients all are essential to differentiate ReA from diseases that may present with similar clinical attributes. Further, and importantly, additional research is required to define the wide diversity in causative agents, epidemiology, and rare case presentations of these arthritides. Finally, new classification and diagnostic criteria, and updated treatment recommendations, are essential to the advancement of our understanding of ReA.

Der Schriftsteller Bertolt Brecht (1898–1956) ist bekannt durch seine Gedichte, Dramen und das von ihm begrundete „epische bzw. dialektische Theater“. Wegen Herzbeschwerden und neuromuskularer Symptome in seiner Jugend wurde bei ihm retrospektiv ein rheumatisches Fieber postuliert. Ausgehend vom heutigen rheumatologischen Wissensstand lasst sich aus den vorliegenden Dokumenten nicht ableiten, dass Brecht sicher ein rheumatisches Fieber hatte. Allenfalls ist eine ganz ungewohnliche Manifestation eines rheumatischen Fiebers zu vermuten mit atypischer rheumatischer Chorea und sehr atypischem Verlauf einer rheumatischen Karditis. Einige Abweichungen vom klassischen Krankheitsbild – das Fehlen von Fieber und Arthritis, keine typische Symptomatik einer Sydenham-Chorea, die fehlende Diagnose eines Herzvitiums in seiner Jugend – fuhren zu umfangreichen differenzialdiagnostischen Uberlegungen. Eine mogliche psychosomatische Genese durch funktionelle Herzbeschwerden muss selbst dann postuliert werden, wenn eine zeitweise vorangegangene organische Ursache nicht ausgeschlossen werden kann. Nur der Einsatz der heute verfugbaren weiterfuhrenden Diagnostik mit Dopplersonographie des Herzens, Kardio-MRT (Magnetresonanztomographie), Rachenabstrichen auf Streptokokken und Streptokokkenserologie wurde ermoglicht haben, die Herzsymptomatik von Brecht in seiner Jugend zweifelsfrei zu diagnostizieren und von funktionellen Herzbeschwerden abzugrenzen. Sein Tod infolge einer bakteriellen Endokarditis mit Nachweis von Coli-Bakterien infolge eines urologischen Eingriffs mit nachfolgenden Fieberschuben und Pyelonephritis ist durch die Auswertung arztlicher Dokumente belegt und zweifelsfrei nachvollziehbar.

Jet-electrolytic Plasma Polishing (Jet-ePP) is a modified form of Bath-ePP to selectively polish and clean local areas with lower-power. When Jet-ePP is used, it must be taken into account how the changed boundary conditions and the additional electrolyte jet parameters influence the basic process. It can be assumed that the plasma polishing changes into electrolytic polishing due to changed boundary conditions, which is not desirable. The non-existent closed boundary conditions must be compensated by setup adjustments. Changes in the phenomenological model of the removal are necessary. The paper shows how the additional and changed process parameters such as fluid flow, distance between anode and cathode influence the individual process phases. Current-time curves are used to investigate the changes in ignition and polishing phases, which are influencing the machining results. Due to these combined data it is possible to find stable process windows. For special changes of the phenomenological model, the physical changes have to be described. To compare the electric parameters such as the voltage drop over the electrolyte of both processes: Jet-ePP and Bath-ePP, equivalent circuit diagrams are used. These describe which changed conditions also lead to the formation of a plasma layer and produce the same effect as in Bath-ePP. In combination with the geometric proportions and the function of the workpiece, the most suitable scientific and industrial application areas are pointed out, making use of the localized jet in comparison with the well-established Bath-ePP process.

Durch die wachsende Produktvielfalt nimmt das Potenzial der additiven Fertigung im Werkzeugbau stetig zu. Ein neuartiger Ansatz ist die hybrid-additive Herstellung von Werkzeugkomponenten mittels Laserauftragschweißen. Mithilfe numerischer Simulationen können effiziente Verfahrstrategien analysiert und prozessbedingte Eigenspannungen und Verformungen reduziert werden. Im Rahmen dieser Arbeit wird ein Finite-Elemente-Modell für den Laserauftragschweißprozess entwickelt und in der Software „LS-Dyna“ validiert. Due to the rising variety of products, the potential of additive manufacturing in tool making is continuously increasing. A novel approach is the hybrid-additive manufacturing of tool components using laser metal deposition (LMD). Numerical simulations can be used to analyze efficient scanning strategies and reduce process-related residual stresses and deformations. Within the scope of this work, a finite-element-model for the LMD process is developed and validated within the software LS-Dyna.

Electrolytic plasma polishing is a hybrid process in which the electrolytic process is an assisting process for a plasma region, which subsequently cleans and polishes the surface of a workpiece. The basic process takes place in an electrolyte bath, where very different starting conditions can be met. The extreme cases are the ignition in the bath, the ignition during a rapid immersion phase and the ignition in a slow immersion phase. Characteristic of these individual cases are the extreme changes of the tool impedance in connection with the electrolyte. The paper shows how the current-voltage characteristic can be measured, without adjustment problems between the process energy source (PES) and the connection impedance. The individual phases of the ignition phase are explained on the basis of a phenomenological model and the changes in the model (equivalent circuit diagram) of the process are taken into account. From these findings, the conditions can be derived to the PES and energy consumption in the ignition phase can be minimized. The basic objective is also to convert the ignition phase into a stable polishing phase and to have as few re-ignition phases as possible during the polishing period. In particular, the boundary conditions for the Bath-PeP are defined, which allow for a fast polishing of the surface, without deteriorating the mechanical properties of the surface or changing the geometry of the functional surface. In contrast to electrolytic polishing, no edge rounding occurs if a correspondingly short processing time is maintained.

Plasma electrolytic Polishing (PeP) is an innovative surface treatment to produce smooth, high-gloss surfaces. It is a thermo-chemical process but often described as a special case of anodic dissolution. PeP is determined by an interplay between plasma chemical, thermochemical, and electrochemical processes. The mechanism is not yet fully understood and part of ongoing research. The planar plasma discharge renders direct observation of the interface extremely difficult. Specially developed flow cells could overcome current experimental limitations. The study investigates phenomena during process initiation, as vapor layer creation and current and temperature signals, using high-speed and thermal imaging to foster understanding and derive optimization strategies

Purpose of Review This article presents a comprehensive narrative review of reactive arthritis (ReA) with focus on articles published between 2018 and 2020. We discuss the entire spectrum of microbial agents known to be the main causative agents of ReA, those reported to be rare infective agents, and those reported to be new candidates causing the disease. The discussion is set within the context of changing disease terminology, definition, and classification over time. Further, we include reports that present at least a hint of effective antimicrobial therapy for ReA as documented in case reports or in double-blind controlled studies. Additional information is included on microbial products detected in the joint, as well as on the positivity of HLA-B27. Recent Findings Recent reports of ReA cover several rare causative microorganism such as Neisseria meningitides, Clostridium difficile, Escherichia coli, Hafnia alvei, Blastocytosis, Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica/dispar, Strongyloides stercoralis, β-haemolytic Streptococci, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Mycobacterium bovis bacillus Calmette-Guerin, and Rickettsia rickettsii. The most prominent new infectious agents implicated as causative in ReA are Staphylococcus lugdunensis, placenta- and umbilical cord–derived Wharton’s jelly, Rothia mucilaginosa, and most importantly the SARS-CoV-2 virus. Summary In view of the increasingly large spectrum of causative agents, diagnostic consideration for the disease must include the entire panel of post-infectious arthritides termed ReA. Diagnostic procedures cannot be restricted to the well-known HLA-B27-associated group of ReA, but must also cover the large number of rare forms of arthritis following infections and vaccinations, as well as those elicited by the newly identified members of the ReA group summarized herein. Inclusion of these newly identified etiologic agents must necessitate increased research into the pathogenic mechanisms variously involved, which will engender important insights for treatment and management of ReA. Supplementary Information The online version contains supplementary material available at 10.1007/s11926-021-01018-6.

The coping with rheumatoid arthritis of the famous French impressionist painter Pierre-Auguste Renoir (1841-1919) is described in former publications. The heavily handicapped painter has in his last years created sculptures in cooperation with the sculptor Richard Guino (1890-1973). The extraordinary genesis of the sculptures through a masterful artistic cooperation, as well as the resulting legal issues and shameful copyright infringements, is reported. Renoir's decision to create sculptures with the help of Guido can be attributed to his remarkable artistic vision, vitality, optimistic nature, and strong will and is also a further testimonial of creative coping of an artist overcoming the physical handicap due to rheumatoid arthritis of his final years, so far not described in detail in the medical literature.

An increase in geriatric population coupled by a growing incidence of different vascular ailments including peripheral vascular and coronary artery diseases imply that the medical devices market will continue to enlarge. As demand for minimally invasive surgical procedures and treatments increase, so does the significance of the abilities of nitinol, including shape memory, superelasticity, high fatigue resistance, corrosion resistance and biocompatibility which have revolutionized the medical device manufacturing sector. In order to fully exploit the capabilities of nitinol, sound and application oriented machining processes have to be selected for optimum efficiency. This is especially so for nitinol since it is a hard material to machine owing to its phase transformation and work hardening. Though stand alone research on processing nitinol is available, vital comparison information regarding to strengths and limitations of different machining processes applied in micromachining nitinol is lacking. This study presents on steps in a nitinol processing chain and offers a juxtaposition between different nitinol manufacturing, forming, machining and post processing methods including pointing out how they may affect final part performance. Different performance measurement parameters have been used to categorize the processes and a suitability analysis has been made which can offer a guide on when to use which method.

Zusammenfassung Hintergrund Mit Einführung der Biologika hat sich die Therapie der rheumatoiden Arthritis (RA) hinsichtlich der Wirksamkeit und Kosten grundlegend gewandelt. Ziel dieser Studie ist es, die der S1-Leitlinie der DGRh entsprechende Versorgung von RA-Patienten mit krankheitsmodifizierenden Medikamenten (disease-modifying anti-rheumatic drugs; DMARDs) anhand von Routinedaten der gesetzlichen Krankenversicherung zu analysieren. Methodik Die Abrechnungsdaten der Techniker Krankenkasse wurden retrospektiv für die Jahre 2011 – 2014 analysiert. Im Rahmen von Subgruppenanalysen wurden Verschreibungs- und Versorgungsunterschiede einzelner in der Leitlinie empfohlener Wirkstoffe wie konventionelle DMARDs und Biologika analysiert. Ergebnisse Die Studienpopulation umfasste 55 538 RA-Patienten (29,7 % inzidente, 70,3 % prävalente; 22,3 % M05: Seropositive chronische Polyarthritis, 77,7 % M06: Sonstige chronische Polyarthritis). Lediglich 21 616 Versicherte (38,9 %) bekamen mindestens einmal innerhalb eines Jahres nach der Erstdiagnose ein in der Leitlinie empfohlenes konventionelles DMARD oder Biologikum verordnet. Bei den inzidenten Patienten lag die Versorgungsquote mit krankheitsmodifizierenden Medikamenten unterhalb der prävalenten Patienten (31,5 vs. 42,1 %). 60,9 % der M05-Patienten und nur 29,7 % der M06-Patienten erhielten einen Einzelwirkstoff nach Index-Diagnose. Wenn ein Basistherapeutikum verordnet wurde, dann wurde dies durchschnittlich innerhalb eines Quartals nach Erstdiagnose verschrieben. Die führende Rolle in der Verschreibung von Basistherapeutika für die Indexmedikation übernimmt der Rheumatologe. Dennoch zeigte sich, dass nur 68,3 % der Patienten mindestens einmal innerhalb eines Jahres nach der Erstdiagnose einen rheumatologisch tätigen Facharzt konsultierten. Schlussfolgerung Mittels einer großen Stichprobe konnten Unterschiede in der leitliniengerechten Verordnung von krankheitsmodifizierenden Arzneimitteln für verschiedene Subgruppen sowie eine Unterversorgung bei nicht vom internistischen Rheumatologen behandelten Patienten aufgezeigt werden.

This work focuses on the production of high conductive Aluminum based MMC or co-cast components obtained by casting processes. The activity started from the “reinforcement” materials to be used for the MMC fabrication. Carbon based materials were chosen and their characterization under the thermal point of view was carried out. Several arrangements for matrix-reinforcement and matrix-insert couples were evaluated and their potential performances were estimated via numerical simulation. Aluminum-Diamond, Aluminum-Reduced Graphene Oxide and Aluminum-Thermal Pyrolytic Graphite components were produced and their performances were experimentally evaluated. Finally, demonstrator utilizing the novel materials were produced and tested in their relevant working condition.

The recent paper from Sepriano et al provides an extremely important new insight on the concept of axial spondyloarthritis (axSpA).1 Clearly, the Gestalt of axSpA is heterogeneous, with three recognisable clinical entities labelled as: ‘pure axial SpA’, ‘axial SpA with peripheral signs’ and ‘axial SpA at risk’. The finding given in the paper suggests a larger overlap between axSpA and pSpA than anticipated at the time when the Assessment of SpondyloArthritis international Society (ASAS) criteria were developed. Thus, the question arises as to how accurately the three recognisable clinical entities of the ASAS classification criteria represent the diseases entities originally lumped together in the historical concept of SpA. The unifying historical concept of SpA lumps together an inter-related yet heterogeneous group of disorders which includes ankylosing spondylitis …

The paper presents ways of utilising the additive manufacturing process 3D-printing using renewable biobased materials, with a focus on adapted packaging for sensitive components. This application provides an attractive scenario for sustainable production and the re- or upcycling of waste material such as wood flour, rice husk or miscanthus fibre. Packaging of prototypes with sensitive or filigree structures or made of fragile materials is currently difficult, because standardized packages are often not suitable and cost for adapted packages are high. Within this study, CAD-data based adapted packaging made of renewable raw materials is addressed. The 3D-printing process was modified for using conditioned biobased fibre and a special binder. Furthermore, a software tool was developed to create adapted packaging designs by using the individual part geometry. In this way and in combination with AM processes, sustainable and biodegradable packaging for complex components can be generated within a short time. The manufactured packaging is conform to the demands of packaging for fragile goods and can be produced just-in-time.