Technische Universität Dresden: Qucosa
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First‑in‑human SPECT/CT imaging of [²¹²Pb]Pb‑VMT‑α‑NET in a patient with metastatic neuroendocrine tumor
No full text²¹²Pb is a promising radionuclide for targeted alpha particle therapy for cancer. Ongoing preclinical and clinical studies are investigating the potential of ²¹²Pb-labeled peptides and antibodies [1,2,3,4,5]. PSC-PEG₂-TOC (VMT-α-NET) is a novel somatostatin receptor subtype 2 (SSTR2) targeting peptide for the treatment of neuroendocrine tumors (NET) that shows rapid tumor accumulation, high tumor retention, and fast renal excretion with the potential for low nephrotoxicity [6, 7]. ... [Aus: Einführung
Damage Analysis and Quality Control of Carbon-Reinforced Concrete Beams Based on In Situ Computed Tomography Tests
No full textCarbon-reinforced concrete (CRC) is increasingly utilized in construction, due to its unique properties, such as corrosion resistance, high-tensile strength, and durability. Understanding its behavior under different loads is crucial to ensuring its safe and effective use in various construction applications. In this study, three-point bending tests were performed in combination with large-scale in situ computed tomography (CT). This paper presents the related three- and four-dimensional evaluation methods, with emphasis on crack width and quality control. The focus was on large CRC beams, with cross-sectional sizes of up to 80 mm by 160 mm. Such dimensions require extremely high energy during a CT scan. Therefore, a new experimental setup with energies of up to 8 MeV was used in this study. However, such high energies posed new challenges to the analysis methods. Therefore, two methods (digital volume correlation and grayscale profile analysis) for accurate crack width estimation were adapted and applied to the 3D reconstructions. In addition, a photogrammetric stereo image sequence was acquired and analyzed, using digital image correlation to cross-validate the results derived from the 3D crack width estimates. The 3D CT images also played a key role in the quality control measures, including the localization of the carbon-reinforcement and the assessment of porosity within the concrete structure
Faseroptik und Schallemission bei Spannungsrisskorrosion - eine innovative Anwendung bei einer Spannbetonbrücke in Dresden
No full textDie Bewertung von spannungsrisskorrosionsgefährdeten Bauwerken ist mit großen Herausforderungen verbunden, da die verborgenen Spannglieder schwer zu inspizieren sind und Spanndrahtbrüche nur unter bestimmten Voraussetzungen zu einer äußerlich erkennbaren Rissbildung führen. Innovative Messtechniken wie Schallemissionssensoren und verteilte faseroptische Sensorik ermöglichen eine frühzeitige Schadenserkennung und ergänzen damit klassische Methoden der Bauwerksprüfung. An der Brücke im luge der Königsbrücker Straße in Dresden wurde pilothaft eine kombinierte Überwachung mit diesen beiden Verfahren implementiert und ein Bewertungskonzept mit quantitativen Grenzwerten definiert. Im bisherigen Überwachungszeitraum von über einem Jahr wurden keine Hinweise auf eine aktive Spannungsrisskorrosion vorgefunden, so dass ein sicherer Betrieb des Bauwerks gegeben ist und verlängerte Planungszeiträume ermöglicht wurden
Erhalt von Eisenbahngewölbebrücken durch Belastungsversuche
No full textGewölbebrücken sind ein wichtiger Bestandteil und gleichzeitig die älteste Bauart im Schienennetz der Deutschen Bahn. Häufig werden sie aufgrund rechnerischer Tragfähigkeitsdefizite und eines mangelhaften äußeren Erscheinungsbildes abgebrochen und ersetzt. Durch Belastungsversuche können die enorme Tragfähigkeit aufgezeigt und Kenntnisse zum Trag- und Verformungsverhalten gewonnen werden. Damit kann der Erhalt von Gewölbebrücken vereinfacht werden. Im Beitrag wird das Konzept der Belastungsversuche anhand der EÜ Straße exemplarisch vorgestellt. Weiterhin werden erste Ergebnisse präsentiert und das weitere Vorgehen skizziert
Duals of Cesàro sequence vector lattices, Cesàro sums of Banach lattices, and their finite elements
No full textIn this paper, we study the ideals of finite elements in special vector lattices of real sequences, first in the duals of Ces`aro sequence spaces cesp for p ∈ {0}∪[1,∞) and, second, after the Ces`aro sum cesp(X) of a sequence of Banach spaces is introduced, where p = ∞ is also allowed, we characterize their duals and the finite elements in these sums if the summed up spaces are Banach lattices. This is done by means of a remarkable extension of the corresponding result for direct sums
Does time really matter? A comparison between virtual and physical field trips
No full textVirtual field trips (VFTs) became widespread during the 2020 COVID-19 pandemic, though as travel restrictions and social distancing measures slowly fade from the global populations memory, the value of VFTs within the education system requires further evaluation. During the pandemic several VFTs were constructed and delivered to MSc. students studying Integrated Petroleum Geoscience at the University of Aberdeen, Scotland
Selective Separation of Lithium, Magnesium and Calcium using 4-Phosphoryl Pyrazolones as pH-Regulated Receptors
No full textEnsuring continuous and sustainable lithium supply requires the development of highly efficient separation processes such as LLE (liquid-liquid extraction) for both primary sources and certain waste streams. In this work, 4-phosphoryl pyrazolones are used in an efficient pH-controlled stepwise separation of Li+ from Ca2+, Mg2+, Na+ and K+. The factors affecting LLE process, such as the substitution pattern of the extractant, diluent/water distribution, co-ligand, pH, and speciation of the metal complexes involved, were systematically investigated. The maximum extraction efficiency of Li+ at pH 6.0 was 94 % when Mg2+ and Ca2+ were previously separated at pH<5.0, proving that the separation of these ions is possible by simply modulating the pH of the aqueous phase. Our study points a way to separation of lithium from acid brine or from spent lithium ion battery leaching solutions, which supports the future supply of lithium in a more environmentally friendly and sustainable manner
Workflow automation for SfM change-detection: an application to rockfalls
No full textThe workflow for change detection from point clouds is well known and used in various scientific fields for monitoring processes. This method was extensively developed in the last two decades with the introduction of LiDAR (Light Detection and Ranging) technology, which allows point clouds to be acquired with exceptional accuracy and speed. However, the advent of SfM-MVS (Structure from Motion - Multi-View Stereo) algorithms, which enables the generation of point clouds at very low cost, makes this method a suitable alternative and one of the most widely used tool for monitoring in the geosciences
Mobile mapping and GeoSLAM for the characterisation and modelling of karst morphologies at the conduit scale
No full textPredicting contaminant and solute transport, forecasting floods and modelling speleogenetic stages are key questions of karst hydrogeology for which some theoretical foundations are still missing. In karst hydrological models, cave passages are treated as tubular segments in which turbulent fluid transport is approximated using the Darcy-Weisbach formula
Hypoxia signaling pathway: a central mediator in endocrine tumors
No full textAdequate oxygen levels are essential for the functioning and maintenance of biological processes in virtually every cell, albeit based on specific need. Thus, any change in oxygen pressure leads to modulated activation of the hypoxia pathway, which affects numerous physiological and pathological processes, including hematopoiesis, inflammation, and tumor development. The Hypoxia Inducible Factors (HIFs) are essential transcription factors and the driving force of the hypoxia pathway; whereas, their inhibitors, HIF prolyl hydroxylase domain (PHDs) proteins are the true oxygen sensors that critically regulate this response. Recently, we and others have described the central role of the PHD/HIF axis in various compartments of the adrenal gland and its potential influence in associated tumors, including pheochromocytomas and paragangliomas. Here, we provide an overview of the most recent findings on the hypoxia signaling pathway in vivo, including its role in the endocrine system, especially in adrenal tumors