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Production Technology for Electric Motors with Hairpin Winding
Get PDFWith the renewed demand for electromobility at the beginning of the new millennium, research into the electric powertrain has gained enormous momentum. The demand for higher and higher gravimetric and volumetric power densities leads to further development of existing electric machines as well as to completely new designs, including hairpin technology.
The individual steps of the manufacturing process were presented in detail in this thesis, with a focus on the in-house developments of the Institute FAPS at the Friedrich-Alexander Universität Erlangen-Nürnberg. Furthermore, the concept of a flexible manufacturing cell for the production of hairpin motors was presented, in which the individual processes developed for a demonstration sta-tor were integrated. The cell consists of a conveyor unit, a straightening unit, two devices for integrating the bending process, a cutting unit, various tools for handling and assembling the bent flat wires into a stator, and the subsequent twisting process. For commissioning, a higher-level programmable logic controller (PLC) must be programmed to link the individual modules and control the production process. The basis for this has already been laid with Grafcet. After successful commissioning, a flexible and efficient production cell is available that can be used not only for the production of molded hairpins, but also for the fast and fully automatic production of I-pins and test specimens. Another con-ceivable application is the processing of formed stranded conduc-tors in the system. Due to the large contact surfaces, the bending device is very gentle on the material. This is a basic requirement for processing stranded wires.
In addition to the research and development work documented in this thesis, other machine topologies have been developed and investigated in the field of traction drives. A further development of the hairpin technology is the so-called continuous hairpin. This eliminates the disadvantage of multiple contact processes by man-ufacturing, winding and assembling the winding in one piece. Oth-er topologies include X-pin motors, axial flux drives and reluctance drives. However, it is not only the electric drive that has changed with the renewed demand for electromobility. The entire automotive manufacturing technology is undergoing a transformation process. Many of the previous manufacturing processes are becoming assembly processes that need to be automated in high-wage countries. In addition to the powertrain, this also includes batteries and on-board electrical systems as well as the production and installation of charging infrastructure. Modern mechanical engineering and the production technology associated with it is therefore the opposite of the usual images of dust, oil and dirt, but a key technology. Also in view of the many transformation projects and measures that have been initiated in Germany since the beginning of the 2020s, education and training in the field of production technology will continue to be of central importance for Germany as a business location in the future. Only with profound knowledge will it be possible to master the many challenges of the future, such as digitalization and the associated costs and organizational adjustments, increasing tech-nological complexity, efficiency and productivity, and especially sustainability and climate neutrality
Comparing the outcome after double level osteotomies in severe valgus and varus knees
Get PDFIntroduction Osteotomies have played an important role in joint preservation surgery of the knee joint for many years. A double level osteotomy is performed for severe varus or valgus deformities. There are numerous publications on double level osteotomies for severe varus deformities, whereas there are no publications on valgus deformities. The hypothesis of this study was to compare the clinical outcome after varus DLO with that after valgus DLO. Material and methods In this retrospective study, 40 DLOs were followed up in 34 patients. In group one (13 cases, age 45.6 (16–61) years) a varization DLO was performed, in group two (24 cases, age 48.3 (20–61) years) a valgization DLO was performed. The pre- and postoperative clinical scores were recorded: Tegner Activity score, Japanese knee society Score and Lysholm Score. The leg axis and knee joint angles were recorded and compared pre- and postoperatively. Results The follow-up period was 24 (6–81) months. The follow-up rate was 73% (27/37). The preoperative leg axis in group one showed an average valgus of 15.9° (9–40°). Group two had an average varus of 12° (8–21°). Postoperatively, the leg axis was 3.4° varus in group one and 0.5° valgus in group two. The mLDFA changed in group one from 83.2° to 90.9°, the MPTA from 95.5° to 87.0°. In group two, the mLDFA changed from 91.9° to 85.9° and the MPTA from 83.3° to 88.3° on average. The JLCA changed in group one from − 3.2 (− 5°–0°) to − 0.5° (− 3–2°) postoperative and in group two from 3.3° (1–8°) to 3.0° (0–6°) postoperative. Tegner score, Lysholm score and Japanese knee Society score all improved significantly in both groups. Patients with a valgus axis have worse clinical scores before surgery than the varus group, but the varus group shows a higher potential for improvement postoperatively. Every patient stated that they would have the operation performed again. Complications were rare, two overcorrections required corrective surgery. Two hinge fractures were treated intraoperatively with additional contralateral plate osteosynthesis. Conclusions Patients show very good clinical results after DLO. The improvements in the valgus knees are greater, but starting from a lower preoperative level, probably due to improvements in both the lateral compartment and the patellofemoral compartment. An important finding was that JLCA is normalizing in valgization DLO but not in varization DLO. This needs to be considered in planning a DLO.Open Access funding enabled and organized by Projekt DEAL.Universitätsklinikum Erlangen (8546
Ischemic stroke prevention in patients with atrial fibrillation and a recent ischemic stroke, TIA, or intracranial hemorrhage: A World Stroke Organization (WSO) scientific statement
Get PDFBackground: Secondary stroke prevention in patients with atrial fibrillation (AF) is one of the fastest growing areas in the field of cerebrovascular diseases. This scientific statement from the World Stroke Organization Brain & Heart Task Force provides a critical analysis of the strength of current evidence on this topic, highlights areas of current controversy, identifies knowledge gaps, and proposes priorities for future research. Methods: We select topics with the highest clinical relevance and perform a systematic search to answer specific practical questions. Based on the strength of available evidence and knowledge gaps, we identify topics that need to be prioritized in future research. For this purpose, we adopt a novel classification of evidence strength based on the availability of publications in which the primary population is patients with recent (<6 months) cerebrovascular events, the primary study endpoint is a recurrent ischemic stroke, and the quality of the studies (e.g. observational versus randomized controlled trial). Summary: Priority areas include AF screening, molecular biomarkers, AF subtype classification, anticoagulation in device-detected AF, timing of anticoagulation initiation, effective management of breakthrough strokes on existing anticoagulant therapy, the role of left atrial appendage closure, novel approaches, and antithrombotic therapy post-intracranial hemorrhage. Strength of currently available evidence varies across the selected topics, with early anticoagulation being the one showing more consistent data. Conclusion: Several knowledge gaps persist in most areas related to secondary stroke prevention in AF. Prioritizing research in this field is crucial to advance current knowledge and improve clinical care.Graphical abstractLASACCJFSM
Unraveling the structural complexity of niobate units in aluminosilicate glasses and glass–ceramics†
Get PDFNiobium-containing glasses and glass–ceramics play an important role in several technological applications, but our understanding of the structure–property relationships of many Nb-containing compositions is still rudimentary. To address the current limitations, the present contribution reports data from synchrotron high-energy X-ray diffraction data to unravel the structural evolution of niobate entities in alkali–aluminosilicate glasses. The data obtained are compared with complementary Raman and solid-state NMR spectroscopy data to provide a better interpretation of the macroscopic properties of the glasses and their crystallization behavior in terms of the glass structure. The data show that the incorporation of niobium into the glass network (from 0.2 mol% to 10 mol%) causes a rearrangement of the units and induces large modifications, particularly in the medium-range order. Nb5+ is present in all glasses predominantly in the form of 6-coordinated [NbO6] units with rather invariant 〈Nb–O〉 bond distances around 2.0 Å. This observation correlates well with the 93Nb NMR data showing similarly small changes in the chemical shift values. A contrasting scenario is presented when looking beyond the first coordination sphere, with a particular focus on the A–Nb (A = alkali) and Nb–Nb correlations. Both are strongly dependent on bulk chemistry, which, in turn, is influenced by the availability and nature of charge-compensating alkali ions. The addition of Nb has a relatively minimal effect on Si and Al units, promoting the association of Nb with other Nb species, thereby initiating the formation of a subnetwork of [NbO6] units in a corner shared environment. Both alkali species and Nb5+ ions in the amorphous state tend to favor a structural arrangement very similar to that of the stable crystalline phase.Evolution of the glass structure with niobium incorporation.Deutsche Forschungsgemeinschaft 10.13039/501100001659Japan Society for the Promotion of Science 10.13039/50110000169
Physicians' and pharmacists' perspective on clarity and clinical relevance of absolute contraindications in “Summaries of Product Characteristics”
Get PDFAims Previous work has identified several limitations in “Summaries of Product Characteristics” (SmPCs), which are associated with risks for patients. The aim of this study was to evaluate pharmacists' and physicians' interpretation of contraindications in SmPCs and reasons for their nonadherence in clinical routine. Methods For 20 commonly missed or ignored absolute contraindications, an anonymous online survey providing 24 clinical example cases (one or two per contraindication) for physicians and pharmacists was developed. Experts in medication safety were asked whether the respective case fulfilled the definition of the contraindication in the SmPC: (a) formally, irrespective of the clinical relevance of the contraindication (17 cases), and (b) whether the contraindication was deemed clinically relevant in each respective case (24 cases). Results Twenty‐seven pharmacists and 27 physicians completed the survey. For only one case (1/17; 5.8%) did all experts agree on the same answer option regarding the formal fulfilment of a given contraindication statement. Experts gave heterogeneous answers regarding the interpretation of a contraindication. For instance, among 10 predefined answer options for the contraindication “active liver disease” in the SmPC of simvastatin, every option was selected by at least six experts. In 17/24 (70.8%) clinical example cases a majority of experts agreed on the clinical relevance of a given contraindication. Key reasons for nonadherence to contraindications were “patient monitoring possible”, “lack of alternative treatment” and “acute/severe situations”. Conclusions Experts' disagreement on the interpretation of contraindications in SmPCs using clinical example cases indicates that further efforts are needed to improve their usability in clinical routine.Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/50110000234
Analysis of β‐Catenin Signalling Activity Suggests Differential Regulation of Ontogenetically Distinct Dentate Granule Neuron Populations
Get PDFABSTRACT In mammals, the dentate gyrus of the hippocampus is one of the few regions where neurogenesis continues throughout life. As a result, the dentate gyrus harbours neurons of ontogenetically different origin. Notably, ontogenetically different dentate granule neurons (DGNs) are morphologically distinct and fulfil specialized functions in hippocampal information processing and plasticity. Development of adult‐born DGNs is tightly controlled by signals released by the complex cellular environment of the adult dentate gyrus. In mice, an adult‐like cytoarchitecture of the dentate gyrus is observed only after postnatal Week 2. The question therefore arises when the signalling environment controlling adult neurogenesis is established and whether development of ontogenetically distinct DGNs is subject to the same regulatory pathways. Here, we analyse BATGAL reporter mice to determine the temporal development of β‐catenin‐signalling activity in the murine DGN lineage. We show that the β‐catenin‐signalling pattern, which is essential for precise dendritogenesis and neuronal maturation in adulthood, emerges only around 2 weeks after birth and continues to be refined over the next weeks. These results indicate that the signalling environment controlling adult neurogenesis is only gradually established and suggest that the development of ontogenetically distinct DGNs is controlled by different mechanisms.Wnt/β‐catenin signalling controls neurogenesis in the dentate gyrus of adult mice. This study describes that the adult pattern of Wnt/β‐catenin signalling in the hippocampal neurogenic lineage is progressively established over the first postnatal weeks. imageDeutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165
Adrenergic β receptors modulate inflammatory responses by regulating immune cell distribution
Get PDFThe immune system consists of multiple organs, cells, and molecules forming an
intricate regulatory network. The distribution of immune cells among organs is crucial
for the development of immune responses. The sympathetic nervous system
modulates immune responses via adrenergic receptors (β-ARs), drugs engaging
those receptors are widely used in clinical practice to treat a variety of diseases and
might affect sympathetic-immune interactions. However, the sympathetic nervous
system-immune interactions related to β-ARs remain unknown, I aimed to evaluate
the role of β-ARs in inflammatory immune responses.
A panel of 12 antibodies targeting main immune cells was deployed in multiparameter
flow cytometry to quantify immune cells in various body compartments and
inflammatory conditions. β-ARs gene knockout mice (Adrb1-/- and Adrb2-/-
) served to explore the role of adrenergic signals in the air pouch chemotaxis model, the bone
fracture healing model and the gouty arthritis model. Using a dimensionality reduction
approach, unsupervised clustering of immune cells helped to precisely identify various
subpopulations with the same panel at different organs. Analysis for acute
inflammation (air pouch chemotaxis model) revealed that β1-AR knockout mice
exhibited neutrophilia, enhanced neutrophil production, and increased migratory
capacity. Analysis for subacute (fracture model) and chronic (gouty arthritis model)
inflammation demonstrated β2-AR knockout mice have a reduced neutrophil
infiltration and decreased swelling at the injury sites, accompany an absence of
systemic inflammation.
This study confirms that that β1-AR signals have an inhibitory effect on the
mobilization of neutrophils during the early stage of inflammation. On the other hand,
β2- AR signals seem to be required for the sustained recruitment of neutrophils and
the establishment of IL-6 related chronic inflammation. Furthermore, advanced flow
cytometry and cluster-based analysis techniques have proven valuable for the
evaluation of immune cell movements in experimental models
Vorhersagekraft von intraoperativer Blutflussmessung bei Anlage arterio-venöser Fisteln auf deren Ausreifung
Get PDFHintergrund und Ziele:
Arteriovenöse Fisteln stellen den häufigsten Langzeitzugang für die Hämodialyse dar. Da in bis zu 30 % der Fälle ein Frühversagen während des Reifungsprozesses auftritt, ist das Ermitteln von Vorhersagefaktoren für eine erfolgreiche AVF-Reifung relevant. In diesem Kontext gewinnen intraoperative Flussmessungen zunehmend an Bedeutung, da sie die Möglichkeit einer direkten Intervention bieten und eine Auswirkung auf das Intervall der Beobachtungen im Rahmen der Nachsorge haben. Das Hauptziel dieser Studie bestand darin zu ermitteln, inwieweit das intraoperativ, mittels Flowmeter gemessene Shuntflussvolumen oder der Pulsatilitäts-Index die Reifung der Shunts vorhersagen kann. Zudem wurde sekundär der Zusammenhang zwischen der peripheren, distalen, mittels SPY gemessenen Handperfusion unmittelbar nach der AVF-Erstellung und dem späteren Auftreten des Steal Phänomens untersucht.
Methoden:
Es wurden 50 Shuntanlagen eingeschlossen, bei denen zwischen Oktober 2019 und November 2020 intraoperative Blutflussmessungen mittels MiraQ™ Vascular System (MediStim, Norwegen) und SPY ELITE System© (NOVADAQ Technologies Inc., Kanada) durchgeführt wurden. Das Flowmeter ermittelte das Blutflussvolumen in ml/min sowie den Pulsatilitäts-Index. Das SPY-System registrierte die An- und Abflutung des Farbstoffs Indocyaningrün (ICG) nach dessen Injektion, um einen möglichen Zusammenhang zum späteren Auftreten des Steal-Phänomens zu untersuchen. Es erfolgten Nachkontrollen mittels Duplexsonographie, Dokumentation von Verschlüssen, Komplikationen und des Zeitpunkts der ersten Shuntpunktion. Die statistische Auswertung umfasste verschiedene Tests wie t-Tests, Mann-Whitney-U Tests, Chi-Quadrat Tests, ROC-Analysen, Log-Rank Tests und Pearson Produkt Moment-Korrelationen, um den Zusammenhang zwischen Flussparametern und klinischem Outcome zu ermitteln.
Ergebnisse und Beobachtungen:
Die Probandengruppe ohne Auftreten eines sofortigen Shuntversagens, zeigte ein höheres durchschnittliches Flussvolumen (342 ml/min) als die Gruppe mit dessen Auftreten (255 ml/min). Außerdem stellte sich für Patienten mit Shuntlokalisation am Oberarm der Zusammenhang zwischen dem Pulsatilitäts-Index und dem Versagen der Ausreifung als positiv signifikant heraus (p 0,05) ergaben sich zwischen den Flussparametern und Sofortverschluss, Frühverschluss ( bzw. ≤ 200 ml/min) und einem Sofortverschluss, Frühverschluss, der Möglichkeit oder Dauer bis zur ersten Punktion oder dem Überleben festgestellt werden; ebenso wenig bei getrennter Betrachtung der Shuntlokalisation oder des Grades der Niereninsuffizienz. Des Weiteren gelang es nicht die Ratio Ingress der Hand als prädiktiv für das Auftreten eines Steal-Phänomens zu bestätigen. Es zeigte sich ein signifikanter Zusammenhang zwischen dem Flussvolumen und dem Ausreifungsversagen bei Patienten mit einer Fistel am Unterarm (p = 0,021). Des Weiteren wurde die primäre Durchgängigkeit in der Niedrigflussgruppe als signifikant höher errechnet als in der Hochflussgruppe (p = 0,015).
Schlussfolgerungen und Diskussion:
Das Ziel, die Prädiktionskraft der intraoperativen Flussparameter auf die Reifung der Shunts zu bestätigen sowie sekundär den Zusammenhang zwischen der peripheren, intraoperativ mittels SPY gemessenen Perfusion und dem späteren Auftreten des Steal-Phänomens darzustellen, konnte nicht umfassend erreicht werden, wenngleich Hinweise darauf aufgezeigt wurden. Die von uns aufgezeigten Diskrepanzen zu etablierten Studien legen weitere Untersuchungen nahe, um unbekannte Mechanismen und Einflussfaktoren qualifizieren zu können. Hierbei sind der Vergleich einheitlicher Messgeräte sowie eine begrenzte Anzahl an Operateuren bzw. standardisierte Mess-Protokolle erforderlich. Ein Einfluss der Narkoseart auf die Perfusion ist zudem nicht auszuschließen
Analysis of Pathogens in Respiratory Tract Infections and Their Effect on Disease Severity: Retrospective Data from a Tertiary Care German Children’s Hospital
Get PDFBackground: Respiratory tract infections (RTIs) represent a frequent cause of inpatient admission in children’s hospitals, especially in the fall and winter seasons, resulting in major healthcare problems due to a lack of beds. The age and seasonal distribution of each pathogen seem to be multifactorial features that influence the course of infection. Other severity predictors appear to be the length of hospital stay, the presence or absence of oxygen demand, and the value of inflammatory markers. Methods: All inpatients from our children’s hospital between 2021 and 2023 who had a nasopharyngeal swab and presented with RTI symptoms were recruited for this retrospective cohort study. The parameters of interest were age, swab result, month of detection, CRP values, duration of hospitalization, presence of oxygen demand, and comorbidities. The data were analyzed using chi-square tests, paired t -tests and regression analysis to determine the associations of differences between the groups. Results: Detection of more than one respiratory pathogen in the same swab, apart from combinations with SARA-CoV-2, influenza, or RS-virus, was not associated with longer hospital stay, higher mean maximal CRP values, or oxygen demand compared to mono-infection with the same pathogens. In contrast, the detection of a pathogen versus no detection could be related to higher rates of oxygen demand and higher CRP values. Conclusions: Since co-infection with more than one virus, excluding those with epidemic potential, was not associated with a more severe course of RTIs, strict patient isolation seems to be dispensable for several viruses, as well as isolation of infected or colonized patients.The authors declare that no funds, grants, or other support was received during the preparation of this manuscript
