Technische Universität Dresden: Qucosa
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Analysis of the Role of Stellate Cell VCAM-1 in NASH Models in Mice
No full textNon-alcoholic fatty liver disease (NAFLD) can progress to non-alcoholic steatohepatitis (NASH), characterized by inflammation and fibrosis. Fibrosis is mediated by hepatic stellate cells (HSC) and their differentiation into activated myofibroblasts; the latter process is also promoted by inflammation. Here we studied the role of the pro-inflammatory adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) in HSCs in NASH. VCAM-1 expression was upregulated in the liver upon NASH induction, and VCAM-1 was found to be present on activated HSCs. We therefore utilized HSC-specific VCAM-1-deficient and appropriate control mice to explore the role of VCAM-1 on HSCs in NASH. However, HSC-specific VCAM-1-deficient mice, as compared to control mice, did not show a difference with regards to steatosis, inflammation and fibrosis in two different models of NASH. Hence, VCAM-1 on HSCs is dispensable for NASH development and progression in mice
70 Jahre Verfahrenstechnik an der TU Dresden
No full textAn der Technischen Hochschule Dresden, der Vorgängereinrichtung der TU Dresden, wurde 1953 mit der Besetzung der Fachprofessur für Verfahrenstechnik eine Fachrichtung „Ingenieur für Verfahrenstechnik“ eingerichtet und das heutige Institut für Verfahrenstechnik und Umwelttechnik begründet. Seitdem wurde das Profil in Ausbildung und Forschung des Instituts innerhalb der Fakultät Maschinenwesen der Technische Universität Dresden (TUD) erheblich weiterentwickelt. Ausgehend von dieser Entwicklung werden die heutigen Forschungsschwerpunkte der fünf Professuren und Arbeitsgruppen vorgestellt.At the Technische Hochschule Dresden, the predecessor institution of the TU Dresden, a specialization “Engineer for Process Engineering” was established in 1953 with the filling of the specialist professorship for chemical engineering, and the present Institute for Process and Environmental Engineering was founded. Since then, the profile in education and research of the institute within the Faculty of Mechanical Science and Engineering of the Technische Universität Dresden (TUD) has been considerably extended. Based on this development, the current main research areas of the five chairs and research groups are presented
Gamma-Aminobutyric Acid and Glutamate Concentrations in the Striatum and Anterior Cingulate Cortex Not Found to Be Associated with Cognitive Flexibility
No full textBehavioral flexibility and goal-directed behavior heavily depend on fronto-striatal networks. Within these circuits, gamma-aminobutyric acid (GABA) and glutamate play an important role in (motor) response inhibition, but it has remained largely unclear whether they are also relevant for cognitive inhibition. We hence investigated the functional role of these transmitters for cognitive inhibition during cognitive flexibility. Healthy young adults performed two paradigms assessing different aspects of cognitive flexibility. Magnetic resonance spectroscopy (MRS) was used to quantify GABA+ and total glutamate/glutamine (Glx) levels in the striatum and anterior cingulate cortex (ACC) referenced to N-acetylaspartate (NAA). We observed typical task switching and backward inhibition effects, but striatal and ACC concentrations of GABA+/NAA and Glx/NAA were not associated with cognitive flexibility in a functionally relevant manner. The assumption of null effects was underpinned by Bayesian testing. These findings suggest that behavioral and cognitive inhibition are functionally distinct faculties, that depend on (at least partly) different brain structures and neurotransmitter systems. While previous studies consistently demonstrated that motor response inhibition is modulated by ACC and striatal GABA levels, our results suggest that the functionally distinct cognitive inhibition required for successful switching is not, or at least to a much lesser degree, modulated by these factors
The origin of the energy split in phase-field fracture and eigenfracture
No full textThe energy splits, which are used in phase-field fracture and eigenfracture, are frequently motivated by the statement that crack nucleation and crack growth have to be prevented at compression loads. The intention of the article at hand is to show that the energy decomposition is an essential part of such fracture models, and to investigate the underlying problem and its physical interpretation. Finally, a general framework for the derivation of physically motivated energy splits is presented, which is not limited to certain bulk material models
Accuracy of Devereux and Teichholz formulas for left ventricular mass calculation in different geometric patterns: comparison with cardiac magnetic resonance imaging
No full textLeft ventricular (LV) myocardial mass is important in the evaluation of cardiac remodeling and requires accurate assessment when performed on linear measurements in two-dimensional echocardiography (Echo). We aimed to compare the accuracy of the Devereux formula (DEV) and the Teichholz formula (TEICH) in calculating LV myocardial mass in Echo using cardiac magnetic resonance (CMR) as the reference method. Based on preceding mathematical calculations, we identified primarily LV size rather than wall thickness as the main source of bias between DEV and TEICH in a retrospective derivation cohort (n = 1276). Although LV mass from DEV and TEICH were correlated with CMR, TEICH did not show a proportional bias as did DEV (− 2 g/m² vs. + 22 g/m²). This could be validated in an independent prospective cohort (n = 226) with symptomatic non-ischemic heart failure. DEV systematically overestimated LV mass in all tiers of LV remodeling as compared to TEICH. In conclusion, the TEICH method accounts for the changes in LV geometry with increasing LV mass and thus better reflects the different pattern of LV remodeling than the DEV method. This has important clinical implications, as TEICH may be more appropriate for use in clinical practice, rather than DEV, currently recommended
Impact of Geometric and Electronic Factors on Selective Hydro-Deoxygenation of Guaiacol by Surface-Rich Metal/Silica Catalysts
No full textThe selective production of hydrocarbons for the chemical industry from biogenic feedstock is a significant challenge when ensuring hydrocarbon and fuel supply, despite the heterogeneity of this feed. In this study, guaiacol, as a surrogate for complex lignin-based biomass resources, is converted by an inert silica carrier material with different d-metal impregnation (Mo, W, Re, Fe, Co, Ni, Cu, Pd, Ag) to reveal the reasons for different product selectivity to hydrogenated and deoxygenated hydrocarbon products. Hydrogen at 15 bar (gauge) and guaiacol are converted on metal/silica catalysts between 250 °C and 400 °C, while the physicochemical catalyst properties are characterized before and after catalytic tests. Volcano plots for the conversion, hydrogenation and deoxygenation products versus the d-band energy, surface atom distance and fouling properties reveal three groups of metals: (i) those that are less active and show high coking (Ag, α-Fe); (ii) those that show high activity for hydrogenation (β-Co, Ni, Pd) and, therefore, preferably yielded cyclohexane, cyclohexanol and 2-methoxycyclohexanol; (iii) those that preferably promote deoxygenation (Mo, W, Re, Cu) and, therefore, promoted the formation of phenol, benzene, anisole and catechol. The results are summarized in a pseudo van Krevelen diagram and interpreted as a complex interdependency from Sabatier’s principle of geometric correspondence of hexagonal metal surface for hydrogenation, electronic correspondence for the activation of hydrogen and electronic correspondence by oxophilicity for deoxygenation from the d-band center model
Masculinity Studies
No full textDer Artikel bietet einen konzisen und umfassenden Überblick über die historische Entwicklung und den aktuellen Stand der Masculinity Studies. Er geht dabei sowohl auf internationale als auch spezifisch deutsche Begebenheiten ein, bspw. bei der Institutionalisierung der Männlichkeitsforschung, diskutiert kritisch die Inflation des Krisenbegriffs in Bezug auf Männlichkeit und schließt mit einem Ausblick auf aktuelle und zukünftige Tendenzen der Masculinity Studies
Between Heteronormativity and Horizontal Homosociality: Alzheimer’s and Masculinity in Alternative German Cinema: Nicht schon wieder Rudi! (2015)
No full textGiven the difference in the representation of constructions of hegemonic masculinity and homosociality promoted in ‘mainstream cinema’ on the one hand and in ‘alternative cinema’ on the other, this article examines how Nicht schon wieder Rudi! (Oh No, Not Rudi Again!) innovatively conceives of and intertwines masculinity, homosociality and Alzheimer’s, and how the film handles the homosocial-homosexual conundrum
Kamerabasierte Positionsbestimmung eines Flugroboters
No full textDas Ziel dieser Diplomarbeit ist die Auswahl, Implementierung und Erprobung eines geeigneten Open-Source-Algorithmus, der Kamerabilder und IMU Messungen zur Positionsbestimmung einer Drohne verwendet.
Im Fokus steht die Untersuchung der Möglichkeiten und Grenzen der Positionsbestimmung bei Drohnen, die für taktile Aufgaben eingesetzt werden.
Nach der Bewertung von verschiedenen Frameworks anhand ausgewählter Kriterien wurde ORB-SLAM3 als geeigneter Algorithmus ausgewählt und auf einem Multikopter mit einer Intel RealSense D435i implementiert.
Anschließend wurden umfangreiche Experimente sowohl handgeführt als auch im Flug durchgeführt, um die Genauigkeit des Systems zu untersuchen.
Dabei wird jeweils zwischen guten (kontrastreichen) und schlechten (kontrastarmen) visuellen Bedingungen unterschieden.
Die Ergebnisse zeigen, dass unter optimalen Bedingungen Fehler unter einem Prozent in Bezug auf den zurückgelegten Weg erreicht werden.
Bei Flügen liegt der Fehler unter guten Bedingungen im Bereich weniger Zentimeter.
In kontrastarmen Umgebungen treten jedoch sowohl bei den handgeführten Versuchen als auch bei den Flügen deutliche Genauigkeitsverluste bis zum Versagen des Systems auf.The aim of this thesis is to select, implement, and test a suitable open-source algorithm that uses camera images and IMU measurements to determine the position of a drone.
The focus lies on investigating the possibilities and limitations of position determination for drones used for tactile tasks.
After evaluating various frameworks based on selected criteria, ORB-SLAM3 was chosen as the suitable algorithm and implemented on a multicopter with an Intel RealSense D435i.
Extensive experiments were then carried out, both hand-held and in flight, to examine the accuracy of the system.
A distinction is made between good (high-contrast) and poor (low-contrast) visual conditions.
The results show that under optimal conditions, errors of less than one percent in relation to the distance traveled are achieved.
During flights, the error under good conditions is in the range of a few centimeters.
In low-contrast environments, however, significant accuracy losses occur in both hand-held tests and flights, causing the system to fail
Hardware Analysis and Implementation of On-Chip Neural Signals Redundancy Reduction Engines
No full textSeit Jahrzehnten arbeiten Neurowissenschaftler und Ingenieure daran, die zugrunde liegende Bedeutung menschlicher Hirnsignale zu entschlüsseln, um Fortschritte in Bereichen wie neuronaler Prothetik und Gehirn-Maschine-Schnittstellen zu erzielen. Angesichts der Herausforderungen bei der Erfassung und der Qualität von Signalen hat die Aufzeichnung und Verarbeitung extrazellulärer neuronaler Signale große Aufmerksamkeit auf sich gezogen.
Konventionelle Systeme zur Aufzeichnung und Verarbeitung extrazellulärer neuronaler Signale bestehen hauptsächlich aus analogen Frontends und Signalübertragungskomponenten. Mit den jüngsten Fortschritten stehen diese Systeme jedoch vor wachsenden Herausforderungen. Um eine umfassende Analyse außerhalb des Chips zu ermöglichen, wurde die Anzahl der aufgezeichneten und verarbeiteten Kanäle stark erweitert. Dieses Wachstum bringt erhebliche Engpässe in Bezug auf Bandbreite, Energieverbrauch und Speicherkapazität mit sich. Ein zentraler limitierender Faktor ist die Bitzahl im Übertragungsstrom, was eine effizientere Datenrepräsentation und Verpackung erforderlich macht. Diese Arbeit konzentriert sich daher auf die Redundanzreduktion in extrazellulären neuronalen Signalen, mit dem Ziel, qualitativ hochwertige Informationen zu übertragen und gleichzeitig mehr Kanäle bei begrenztem Energieverbrauch zu unterstützen.
Extrazelluläre neuronale Signale umfassen Aktionspotenziale, lokale Feldpotenziale und andere Komponenten, die jeweils unterschiedliche Anwendungsbereiche haben. In dieser Arbeit werden verschiedene Dekorrelations- und Kompressionsalgorithmen untersucht und angewendet, um die für eine verlustfreie oder nahezu verlustfreie On-Chip-Kompression von Aktionspotenzialen und lokalen Feldpotenzialen erforderliche Bitrate zu reduzieren. Angesichts der Bedeutung der Spike-Sortierung wird außerdem die On-Chip-Klassifikation erforscht, die ausschließlich die Spike-Indizes ausgibt.
Die Studie ist hauptsächlich nach Chip-Iterationen strukturiert und analysiert algorithmische Prioritäten in verschiedenen Untersuchungs- und Designphasen, identifiziert Schwachstellen, implementiert schrittweise Verbesserungen und erweitert die Funktionalität des Chips. Zusätzlich wird eine detaillierte Dokumentation jedes Algorithmus bereitgestellt, um als umfassende Referenz für verschiedene praktische Anwendungen zu dienen.For decades, neuroscientists and engineers have been committed to uncovering the underlying meanings of human brain signals, aiming to advance fields such as neural prosthetics and brain-machine interfaces. Considering the recording difficulty and signal quality, the recording and procesing of intracortical neural signals has gained significant attention.
Conventional intracortical neural signal recording and processing systems primarily consist of analog frontends and signal transmission components. However, with recent advancements, these systems face challenges. Specifically, to support comprehensive off-chip analysis, the number of recording and processing channels has been greatly expanded. This growth brings significant bottlenecks on bandwidth, power consumption, and storage capacity. A key limiting factor is the bit number of the transmission stream, necessitating more efficient data representation and wrap. Thus, this study focuses on the redundancy reduction in intracortical neural signals, aiming to transmit high-quality information while supporting more channels with a limited power budget.
Intracortical neural signals consist of action potentials, local field potentials, and other components, each with distinct applications. In this work, employ various decorrelation and compression algorithms are investigated and employed to reduce the bit rate required for lossless or near-lossless on-chip compression of action potentials and local field potentials. Furthermore, given the importance of spike sorting, the on-chip neural classification that outputs only spike indices is also explored.
This study is structured primarily according to chip iterations, analyzing algorithmic priorities across different investigation and design phases, finding out shortcomings, implementing successive improvements, and enhancing chip functionality. Additionally, detailed documentation of each algorithm is provided to serve as a comprehensive reference for various practical applications