The 50 most recently published documents
Compensation Techniques for Inductive-Distorted Measurements of Fast Transients in Double Pulse Test
(2025)
A FEA-based Method for Determining the Thermal Equilibrium in Self-Heating of Magnetic Components
(2025)
Design of a SiC-based High Bandwidth Switch-Mode Power Amplifier as Grid Emulator for a PHIL-System
(2025)
On the Importance of Appropriate Current Probes for Double Pulse Tests and How to Select Them
(2025)
The epithelial sodium channel (ENaC) is essential for osmoregulation in tetrapod vertebrates. There are four ENaC-subunits (α, β, γ, δ) which form αβγ- or δβγ-ENaCs. While αβγ-ENaC is a ‘maintenance protein’ controlling sodium homeostasis, δβγ-ENaC might represent a ‘stress protein’ monitoring high sodium concentrations. The δ-subunit emerged with water-to-land transition of vertebrates. We examined ENaC evolution in Cetartiodactyla, a group including even-toed ungulates and cetaceans (whales, dolphins and porpoises) which returned to marine environments in the Eocene. Genes for α-, β-, and γ-ENaC are intact across Cetartiodactyla. While SCNN1D (δ-ENaC) is intact in terrestrial Artiodactyla, it is a pseudogene in cetaceans. A unique fusion of SCNN1D exons 11 and 12 is observed in the Antilopinae. Transcripts of α-, β-, and γ-ENaC are present in kidney, lung and skin tissues of Bottlenose dolphins, underscoring αβγ-ENaC’s maintenance role. Bottlenose dolphins and Beluga whales do not show behavioural differences between sodium-containing and sodium-free stimuli, supporting a function of δ-ENaC as a sodium sensing protein which might have become obsolete in high-salinity marine environments. Consistently, there is reduced selection pressure or pseudogenisation of SCNN1D in other marine mammals. Erosion of SCNN1D might therefore be a consequence of environmental transition in marine mammals.
PURPOSE
Retro-muscular mesh augmentation is standard for repairing abdominal incisional or larger primary hernia. A wide variety of meshes with diverse properties are available. The knowledge on the immune-modulating effects of meshes is, however, insufficient. This study investigates the impact of two widely used lightweight meshes, ULTRAPRO® and ProGrip™, on macrophage activation (in vitro), systemic inflammation (in vivo), patient perioperative and long-term outcomes.
METHODS
Human THP-1 cell-derived macrophages were cultured in absence and presence of ULTRAPRO® or ProGrip™ meshes. The release of pro-inflammatory cytokines, interleukin (IL)-1β and IL-6, was measured following inflammasome activation. In a retrospective study, systemic inflammation and postoperative outcomes after retro-muscular hernia repair using ULTRAPRO® (321 patients) or ProGrip™ (161 patients) meshes were analyzed.
RESULTS
In the presence of ULTRAPRO®, IL-1β and IL-6 release by macrophages was increased, whereas ProGrip™ tended to reduce cytokine levels (p ≤ 0.05; n = 7). Baseline characteristics were comparable between both groups; systemic C-reactive protein levels were likewise higher in patients receiving ULTRAPRO® compared to ProGrip™ (mean difference: 26.9 ± 7.5 mg/dl; p < 0.0001). No relevant differences were observed in perioperative morbidity or short-term outcomes, including complications and hospitalization after hernia repair, but hernia recurrence rates tended to be higher within three-year follow-up after ProGrip™ implantation compared to ULTRAPRO® (p = 0.0630).
CONCLUSION
Meshes exhibit distinct immune-modulating effects on macrophages, leading to differential activation that may influence foreign-body reaction and systemic inflammation. These immune responses potentially impact clinical outcomes and recurrence after hernia repair. This study underscores the need for comparative prospective, randomized-controlled trials to further evaluate the clinical relevance of mesh-specific immunological effects.
To Be Real or Not to Be
(2023)
The dataset comprises responses generated by ChatGPT using three different models (GPT-3.5, GPT-4o, and o1preview) evaluated for their effectiveness as an automated tutor in economics education at universities. The dataset focuses on two key use cases:
Explanations of 56 Basic Economic Concepts
Answers and Explanations to 25 Multiple-Choice Questions
The concepts and questions were sourced from CORE Econ’s The Economy 1.0 textbook. The selected content includes foundational ideas like "Opportunity Costs" and "Aggregate Demand," as well as more advanced topics such as "Asymmetric Information" and "Economic Rent."
Responses were generated using standardized prompts that simulate student interactions with ChatGPT. Each response was evaluated using a detailed marking grid that included both problem-specific and response-specific indicators—such as accuracy, scope, error types. A moderation process was applied to ensure reliability, with disagreements resolved through discussion.
The final dataset consolidates all model outputs, and their evaluations. It is suitable for analyzing the pedagogical potential and limitations of large language models in educational contexts. Further, all scripts used to evaluate the responses and perform the statistical analysis are included.
For more detail see the paper: Brose, Natalie, Christian Spielmann, and Christian Tode. ChatGPT as Economics Tutor: Capabilities and Limitations. School of Economics, University of Bristol, UK, 2025.
https://econpapers.repec.org/RePEc:bri:uobdis:25/786
Dieses Lehrbuch schlägt die Brücke zwischen den betriebswirtschaftlich-organisatorischen Methoden und deren digitaler Umsetzung, denn Prozessmanagement heißt zunehmend Gestaltung betrieblicher Aufgaben. Neben methodischen Grundlagen bietet das Werk viele Praxisbeispiele und Übungen. Das Buch von Prof. Gadatsch gilt mittlerweile als der "aktuelle Klassiker", DAS maßgebliche Standardwerk zur IT-gestützten Gestaltung von Geschäftsprozessen. (Verlagsangaben)
We have characterized families of phenylpiperazine (PP) compounds, studying their relative activity with α7 and α9* nicotinic acetylcholine receptors (nAChRs) and focusing on the effects of side groups on the phenyl ring (R1) and the effects of different alkyl groups on the base nitrogen. In this study, we evaluated the impact of methyl substitution on the piperazine ring, which introduced a chiral center, enabling the generation and separation of stereoisomers. Methyl groups were added to either the C2 or C3 positions on the piperazine of the α9α10 agonist/α7 partial agonist PA-EMPP. Additions at the C3 position greatly reduced activity, while additions at the C2 position had selective effects on either α7 or α9/α10 activity. The 2-methyl S and R isomers of PA-EMPP contain a second chiral center at the nitrogen. Notably, replacing the terminal substitution with N,N-dimethyl abolished α9/α910 agonist activity, rendering the compound selective for α7. We also tested 2M isomers of the α9α10 agonist pCN-EMPP and obtained similar enantioselective activity as observed with the PA-EMPP isomers. Compounds were studied for their ability to reduce the ATP-dependent release of IL-1β from monocytes, one aspect of the cholinergic anti-inflammatory activity. Results were consistent with their apparent activation or antagonism of α9* receptors. These findings underscore the critical role of chirality and structural modifications in fine-tuning receptor selectivity, offering valuable insights for the rational design of selective nicotinic therapeutics.
The working group “Air Analyses” of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified the presented analytical method. It is used to determine the levels of 4-methyl-3-penten-2-one [141-79-7] that occur in the workplace air. The method covers concentrations in the range from one tenth up to twice the current occupational exposure limit value (OELV) of 8.1 mg/m3. The method is also suitable for verifying the short-term exposure limit (STEL; excursion factor 2). Samples are collected by drawing a defined volume of air through a sampling tube filled with silica gel using a flow regulated pump at a volumetric flow rate of 0.5 l/min. Exposure during the shift is measured with a sampling period of 2 hours and the short-term exposure with a period of 15 minutes. The 4-methyl-3-penten-2-one adsorbed to the silica gel is extracted by liquid extraction with methanol and analysed by high-performance liquid chromatography using diode array detection. The quantitative determination is based on multiple-point calibrations with external standards. A relative limit of quantification (LOQ) of 0.06 mg/m3 is obtained for an air sample volume of 60 litres. As the LOQ for a sample volume of 30 litres is 0.03 mg/m3, the STEL can also be measured. The recovery is approx. 100% and the expanded uncertainty is 14% for a sampling period of 2 hours and below 16% for a period of 15 minutes.
Konzeptentwicklung eines kostengünstigen Ultraschall-Laufzeit-Sensors zur Verwendung in Anemometern
(2025)
Das Verständnis urbaner Windfelder ist zentral für eine klimaangepasste Stadtplanung, da Windströmungen die Verteilung von Hitze und Schadstoffen wesentlich beeinflussen. Um nachhaltig Maßnahmen in der Stadtplanung durchsetzen zu können, braucht es verlässliche Winddaten. Diese liefern unter anderem 3D-Ultraschall-Anemometer, deren hohe Kosten jedoch den flächendeckenden Einsatz erschweren. Ziel dieser Arbeit ist daher die Machbarkeitsuntersuchung einer kostengünstigen Ultraschallsensorik.
Das Funktionsprinzip eines Ultraschall-Anemometers beruht darauf, dass die Ausbreitungsgeschwindigkeit des Schalls in der Luft von der Bewegungsgeschwindigkeit und -richtung der Luft abhängt. Durch bidirektionale Messung kann die Windgeschwindigkeit kollinear zu der Achse zwischen zwei Schallwandlern unabhängig von Temperatur und Luftfeuchtigkeit bestimmt werden. Für die Umsetzung einer kostengünstigen 1D-Sensorik werden dafür in dieser Arbeit zwei Messansätze zur Messung der Windgeschwindigkeit evaluiert: Die direkte Laufzeitmessung des Schalls mittels eines TDCs (Time-to-Digital-Converter), sowie die Auswertung der Spannungsverläufe mittels eines ADCs (Analog-Digital-Converter). Die Umsetzung dieser beiden erfolgt in einem gemeinsamen Prototyp. Dabei werden sowohl die Hard- als auch die Software dessen entwickelt.
Für beide Messverfahren wird jeweils der optimale Abstand der Schallwandler ermittelt. Es werden beide Methoden, sowie ein kommerzielles Referenzmessgerät in einem Windkanal getestet, der durch Strömungsgleichrichter einen laminaren Luftstrom gewährleistet. Aus Budgetund Zeitgründen steht lediglich ein unkalibriertes Referenzmessgerät zur Verfügung. Es weist Schwankungen über einen längeren Zeitraum auf. Dadurch ist eine Aussage über die Genauigkeit des Prototyps kaum zu treffen. Dennoch sind die Ergebnisse beider Verfahren des Prototyps vielversprechend. Das Messen der Windgeschwindigkeit ist mit der entwickelten Ultraschallsensorik möglich. Diese Arbeit liefert die Grundlage für eine Weiterentwicklung des Systems. Eine 3D-Sensorik ist anzustreben.
Background: Transdermal therapeutic systems use substance transport through the skin to provide an active pharmaceutical ingredient. To ensure a reliable supply, adhesion to skin must be guaranteed. In practice in vivo studies as well as in vitro studies on steel (ISO-standard for self-adhesive tapes) are used. As in vitro—in vivo correlation is poor, extensive in vivo studies are applied during industrial product performance tests. Hence, a specialized skin substitute material for in vitro adhesion testing is needed.
Materials and Methods: Synthetic leather (polyurethane), silicone (Dragon Skin), gelatines, and VitroSkin are used as skin substitute materials. For topographical analysis, reflected light microscopy and confocal light microscopy are applied. Infrared spectroscopy is performed for analysis of functional groups. Dermatological skin probe systems are used to analyze friction, surface pH, and elasticity. To bundle all data with regards to skin similarity, mid-level data fusion is applied.
Results: For all substitute materials, common topographic characteristics compared to human skin can be observed. However, all materials show limitations regarding their topography. Gelatine and VitroSkin feature comparable surface functionality compared to human skin. All materials show significant deficits in their mechanical properties. All characteristics can be summarized as the Skin Similarity Index to give a comprehensive overview regarding substitutes similarity to skin.
Conclusions: A comprehensive evaluation of topography, chemical functionality, and mechanical properties regarding a skin substitutes similarity to human skin was performed. This data should be considered as a baseline for further research in the field of adhesion to skin. By adding further characteristics and materials, it is a versatile approach that can be implemented in a variety of areas.
The transition to sustainable energy systems does not only entail changes to existing technologies or infrastructure. It also involves significant changes in a country's institutional frameworks that are rarely examined. Anchored in institutional analysis, this paper analyses the political economy factors influencing institutional change towards a sustainable energy transition in Ghana, with a particular focus on solar photovoltaics (PVs). The findings indicate that even though progress has been slow moving and incremental, the process of institutional change is cumulative and constitutes a fundamental third-order change. Institutional legacies within the energy sector present strong but not prohibitive barriers to renewable energy adoption. Initially, the relatively homogenous nature of preferences among key actors facilitated the introduction of solar PV. However, conflicting interests among policymakers, who simultaneously support solar PVs and fossil-fuel agendas emerged during a later phase and undermined progress. The declining cost of solar PV systems over time has, nonetheless, provided new momentum for change. Environmental conditions or shocks exogeneous to the reform domain have had mixed effects on Solar PV adoption. While Ghana's numerous power crisis exposed the inadequacies of hydro and thermal sources and created an opportunity for solar PVs, the discovery of oil and gas resources in 2007 significantly slowed change. Although international concerns about climate change and sustainable development have provided some momentum for policy change, perceived injustices in international relations between countries in the Global South and those in the Global North tend to slow the transition process down.
Interactions between consumers and companies are increasingly relying on technologies such as chatbots and voice assistants that are based on natural language processing (NLP) techniques. With the advent of more sophisticated technologies such as transformers and generative artificial intelligence, this trend will likely continue and further solidify. To our knowledge, this study is the first to systematically review the current scientific discourse on NLP-based technologies in the context of the customer journey and attempts to outline existing knowledge and identify gaps before the onset of a new era in NLP sophistication. Employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method and co-occurrence analysis, we offer new and nuanced insights into the prevailing discourse. From a sample of 734 articles, 41 studies were selected and analyzed. Our findings shed light on the current research focus, exploring various technologies, concepts, and challenges. We also offer a starting point for how emerging NLP-based technologies could impact the customer journey, as well as future research directions.
This curriculum is one of the outcomes of the research project „Public Humanities and Pedagogy in the Global South“, funded by the Government of India (SPARC project no. 1871). The project brought together an international and interdisciplinary team, with meetings in Germany (2024) and India (2025). As part of our collaboration, we designed a new course tailored for STEM students at BITS-Pilani, Goa Campus. Each contributor brought unique disciplinary perspectives to the course and taught sessions to a diverse group of students during the spring semester of 2025. The course evolved into an intercultural learning space and provided a platform not only to examine the classic „two cultures“ divide—between the natural and engineering sciences on the one hand and humanities and social sciences on the other—but also to engage with the cultural and national diversity of our team. More broadly, we reflected on Indian-German research collaboration, the role that the humanities in technically-oriented institutions of higher learning (such as German Technical Universities), and the dynamics and challenges of international academic collaboration.We are convinced that the long-standing debate on the „two cultures“ remains a productive starting point for students, educators and researchers interested in critically examining their roles and positions within their institutions, academic communities, and the global system of science and higher education. The topics and ideas presented here build on the course developed for BITS-Pilani and is intended not as a fixed program, but as a flexible toolkit. It is designed for educators seeking to create and adapt similar courses—particularly in alternative institutional and international contexts. The idea of publishing such “core curricula” as open educational resources emerged in connection with another project: the Rhine Ruhr Center for Science Communication Research (RRC), funded by the Volkswagen Foundation (2021-2026). A central insight of our work is that teaching—especially in interdisciplinary settings—should be recognized as a vital form of science communication. Here, students are not seen as passive recipients of knowledge, but as active intermediaries who bridge the different lifeworlds of the university, their communities, personal networks, and their future professions.
Arm's Platform Security Architecture (PSA) is a family of hardware and firmware security specifications, along with open-source reference implementations, aimed at helping device makers and chip manufacturers integrate best-practice security into their products. Devices that comply with PSA can generate attestation tokens as described in this document, which serve as the foundation for various protocols, including secure provisioning and network access control. This document specifies the structure and semantics of the PSA attestation token.
The PSA attestation token is a profile of the Entity Attestation Token (EAT). This specification describes the claims used in an attestation token generated by PSA-compliant systems, how these claims are serialized for transmission, and how they are cryptographically protected.
This Informational document is published as an Independent Submission to improve interoperability with Arm's architecture. It is not a standard nor a product of the IETF.
For cosmopolitan communication studies, media development is a field of utmost relevance. Whenever organizations—traditionally from the Global North—intervene in the media systems and journalism cultures of transformation or (post-)conflict societies, different concepts and norms of news and news making collide. Mostly “Western” actors—state- or privately funded, from major global actors like the NGO Internews to small but highly visible foundations like the Swiss-based Fondation Hirondelle—address media practitioners and newsrooms that act in profoundly different political and economic contexts—even if they share normative concepts of journalism with donors.
Why is the printed press booming in India but declining in the USA? Why are Swiss citizens voting to keep public service broadcasting fees, while France is abolishing them? Why are press councils a tool of media accountability in one country and a tool of gov ernment control in another? Why are the media systems that developed in the countries of the former Soviet Union so different?
Toxic and environmentally harmful components of pyrotechnic compositions require to be substituted with alternative substances. Therefore, the subject of this work was the burning rate investigation of the Al/SrO2 and Si/CaO2 pyrotechnic delay compositions. The delay elements were prepared by pressing the compositions into pellets and transferring them into delay tubes. However, the Al/SrO2 pellets were also placed into the delay tube and post-pressed to determine if any differences in the burning rate were measurable. The dependency of the burning rate in relation to the pellet diameter, binder content, delay tube material, and artificial aging of the compositions was investigated. Further, the impact of the aging as well as of the binder content on the ignition temperature of the compositions was determined. The used silicon powders were characterized by means of Raman spectroscopy, particle size analysis, and BET surface area analysis. Raman spectroscopy was also used to investigate differences between the freshly prepared and artificially aged pyrotechnic compositions. The investigation of friction and impact sensitivity of the compositions, with and without use of the binder, resulted in the classification of both compositions as insensitive. In addition, the mechanical pellet stability in dependency of the binder content was determined, which increased with the binder content.
Gesunde Führung mit SCOAP
(2025)
This dataset supports the dissertation "Balancing Biodiversity and Economic Viability: Farmers' Motivation and Challenges in Nature-Protected Areas".The study explores the potential transfer of farmers' motivations to adopt biodiversity-friendly practices to Maslow's Hierachy of Needs. This investigation employs a multifacetd approach, including qualitative focus group interviews with farmers operating within nature-protected areas and a structured content anaylsis guided by Mayring's methodology.Data collection and Implementation:The focus group interviews were conducted in April 2022 by the policy research institue "dimap", commissioned within the framework of the dissertaion project. The study design and focus group guiede were developed by the author in close collaboration with dimap. While dimap moderated, recorded and transcribed the interviews, the coding and analysis were carried out by the author using ATLAS.ti.
Dieses Einführungspapier ist als Orientierungshilfe zum Thema Künstliche Intelligenz (KI) (engl. Artifical Intelligence, AI) im DaF/DaZ-Kontext gedacht. Ausgehend von häufig gestellten Fragen enthält es grundsätzliche Informationen zu technischen und historischen Hintergründen, didaktisch-methodische Reflexionsanregungen sowie praktische Ideen zum Einsatz von KI im DaF/DaZ-Kontext. Es handelt sich beim vorliegenden Papier um die aktualisierte Version 2.0, die in einigen Kapiteln Anpassungen und Ergänzungen erfahren hat. Das Kapitel „Auf in die Praxis“ wurde gänzlich überarbeitet.
The accurate treatment of outflow boundary conditions remains a critical challenge in computational fluid dynamics when predicting aerodynamic forces and/or acoustic emissions. This is particularly evident when employing the lattice Boltzmann method (LBM) as the numerical solution technique, which often suffers from inaccuracies induced by artificial reflections from outflow boundaries. This paper investigates the use of neural networks (NN) to mitigate these adverse boundary effects and enable truncated domain requirements. Two distinct NN-based approaches are proposed: (1) direct reconstruction of unknown particle distribution functions at the outflow boundary; and (2) enhancement of established characteristic boundary conditions (CBC) by dynamically tuning their parameters. The direct reconstruction model was trained on data generated from a 2D flow over a cylindrical obstruction. The drag, lift, and Strouhal number were used to test the new boundary condition. We analyzed results for various Reynolds numbers and restricted domain sizes where it demonstrated significantly improved predictions when compared with the traditional Zou & He boundary condition. To examine the robustness of the NN-based reconstruction, the same condition was applied to the simulation of a NACA0012 airfoil, again providing accurate aerodynamic performance predictions. The neural-enhanced CBC were evaluated on a 2D convected vortex benchmark and showed superior performance in minimizing density errors compared to CBCs with fixed parameters. These findings highlight the potential of NN-integrated boundary conditions to improve accuracy and reduce computational expense of aerodynamic and acoustic emissions simulations with the LBM.
The role of gut microbiome in obesity and metabolic dysfunctions: Insights and therapeutic potential
(2025)
Obesity is a chronic inflammatory disease defined by an excessive accumulation of body fat. The human gut microbiota (GM) is an intricate ecosystem of microorganisms living symbiotically within the gastrointestinal tract and has emerged as a key player in health and metabolic diseases. Recently, several studies have increasingly revolved around understanding the specific compositions and strains of GM and their potential impact on obesity. This review provides a summary of the most recent findings regarding obesity and newly developed therapies that show exceptional efficacy in treating this condition. In addition, it explores different GM strains that may contribute to the progression and development of obesity. This article summarizes the molecular insights involved in the relationship between obesity and GM, the characteristics of this ecosystem, and its involvement in human metabolism, energy balance, and inflammation leading to obesity. Furthermore, it examines the bacteria most engaged in managing obesity. These findings contribute to a better understanding of this significant and intricate relationship, ultimately aiding in obesity prevention.
Polyphenols, a diverse group of phytochemicals, are an indispensable component of the antioxidant defense system, given their capacity to neutralize free radicals and modulate redox reactions. This review examines the chemical diversity and antioxidant potential of polyphenols derived from viticultural byproducts, including grape skins, seeds, pomace, and stems. These biomass sources provide a sustainable reservoir of bioactive compounds with potential applications in the development of functional and biobased materials. This review also addresses the methodological challenges inherent to this field, such as the variability of extraction procedures and test conditions. This study critically examines the influence of the structural characteristics of polyphenols, including the number, nature, and distribution of hydroxyl groups as well as molecular size, on antioxidant activity. Additionally, innovative extraction techniques that enhance yield and bioactivity are presented and evaluated. Besides conventional monomeric and oligomeric polyphenolic compounds, lignins, a class of high-molecular-weight polyphenols of industrial importance and stability in oxidative environments, are addressed. The results underscore the necessity for standardized multiassay approaches to precisely assess antioxidant capacity and facilitate targeted polyphenol application in diverse fields. Future research should address the intricate interplay between biomass composition, extraction parameters, and polyphenol functionality to tailor their utilization.
Hepatic insulin resistance is an important pathophysiology in type 2 diabetes, and the mechanisms by which high-caloric diets induce insulin resistance are unclear. Among vertebrate animals, mammals have retained a unique molecular change that allows an intracellular arrestin domain-containing protein called Thioredoxin-Interacting Protein (TXNIP) to bind covalently to thioredoxin, allowing TXNIP to "sense" oxidative stress(1). Here, we show that a single cysteine in TXNIP mediates the development of hepatic insulin resistance in the setting of a high-fat diet (HFD). Mice with an exchange of TXNIP Cysteine 247 for Serine (C247S) showed improved whole-body and hepatic insulin sensitivity compared to wild-type (WT) controls following an 8-week HFD. HFD-fed TXNIP C247S mouse livers also showed improved insulin signaling. The Transmembrane 7 superfamily member 2 (Tm7sf2) gene encodes for a sterol reductase involved in the process of cholesterol biosynthesis (2). We identified TM7SF2 as a potential mediator of enhanced insulin signaling in HFD-fed TXNIP C247S mouse livers. TM7SF2 increased Akt phosphorylation and suppressed gluconeogenic markers PCK1 and G6Pc specifically under oxidative-stress-induced conditions in HepG2 cells. We also present data suggesting that a heterozygous variant of TXNIP C247 is well-tolerated in humans. Thus, mammals have a single redox-sensitive amino acid in TXNIP that mediates insulin resistance in the setting of a HFD. Our results reveal an evolutionarily conserved mechanism for hepatic insulin resistance in obesity. Hepatic insulin resistance is an important pathophysiology in type 2 diabetes, and the mechanisms by which high-caloric diets induce insulin resistance are unclear. Among vertebrate animals, mammals have retained a unique molecular change that allows an intracellular arrestin domain-containing protein called Thioredoxin-Interacting Protein (TXNIP) to bind covalently to thioredoxin, allowing TXNIP to "sense" oxidative stress. Here, we show that a single cysteine in TXNIP mediates the development of hepatic insulin resistance in the setting of a high-fat diet (HFD). Mice with an exchange of TXNIP Cysteine 247 for Serine (C247S) showed improved whole-body and hepatic insulin sensitivity compared with WT controls following an 8-week HFD. HFD-fed TXNIP C247S mouse livers also showed improved insulin signaling. The Transmembrane 7 Superfamily Member 2 (Tm7sf2) gene encodes for a sterol reductase involved in the process of cholesterol biosynthesis. We identified TM7SF2 as a potential mediator of enhanced insulin signaling in HFD-fed TXNIP C247S mouse livers. TM7SF2 increased Akt phosphorylation and suppressed gluconeogenic markers PCK1 and G6Pc specifically under oxidative stress-induced conditions in HepG2 cells. We also present data suggesting that a heterozygous variant of TXNIP C247 is well tolerated in humans. Thus, mammals have a single redox-sensitive amino acid in TXNIP that mediates insulin resistance in the setting of an HFD. Our results reveal an evolutionarily conserved mechanism for hepatic insulin resistance in obesity.
Since the public release of ChatGPT in late 2022, the role of Generative AI chatbots in education has been widely debated. While some see their potential as automated tutors, others worry that inaccuracies and hallucinations could harm student learning. This study assesses ChatGPT models (GPT-3.5, GPT-4o, and o1preview) across important dimensions of student learning by evaluating their capabilities and limitations to serve as a non-interactive, automated tutor. In particular, we analyse performance in two tasks commonly used in principles of economics courses: explaining economic concepts and answering multiple-choice questions. Our findings indicate that newer models generate very accurate responses, although some inaccuracies persist. A key concern is that ChatGPT presents all responses with full confidence, making errors difficult for students to recognize. Furthermore, explanations are often quite narrow, lacking holistic perspectives, and the quality of examples remains poor. Despite these limitations, we argue that ChatGPT can serve as an effective automated tutor for basic, knowledge-based questions—supporting students while posing a relatively low risk of misinformation. Educators can hence recommend Generative AI chatbots for student learning, but should teach students the limitations of the technology.
In der vorliegenden Arbeit werden die nematischen Flüssigkristallgemische (E7 und E8) zum Zwecke der Gassensorik mit einer reaktiven, optisch aktiven Substanz dotiert. Die Dotierung verursacht die Ausbildung einer chiral-nematischen Phase, die einen eindimensionalen photonischen Kristall mit Reflexionsmaxima im sichtbaren Bereich des elektromagnetischen Spektrums erzeugt. Infolge einer chemischen Reaktion des Dotiermittels mit dem einem Analyten, ändert sich mit seiner chemischen Zusammensetzung auch dessen helical twisting power (HTP). Diese Änderung verursacht eine Verschiebung des reflektierten Wellenlängenbereichs, was als Änderung der farblichen Erscheinung mit dem bloßen Auge wahrgenommen werden kann. In dieser Arbeit wird das koaxiale Elektrospinnen verwendet, um Flüssigkristalle in Polymerfasern von wenigen Mikrometern Durchmesser einzukapseln. Der Vergleich zwischen eingekapseltem und nicht eingekapseltem dotierten Flüssigkristall wird mit einer dafür entwickelten Reaktionskammer UV/VIS-spektroskopisch durchgeführt. Die ablaufenden Reaktionen werden mittels FTIR-Spektroskopie untersucht. Die Fasern und die verwendeten Flüssigkristalle werden lichtmikroskopisch charakterisiert. Es werden zusätzlich Möglichkeiten untersucht die Wasserbeständigkeit der hergestellten Fasern zu verbessern, um ihre Eignung für künftige technische Anwendungen zu steigern. Hierzu wird das triaxiale Elektrospinnen verwendet, um die Fasern mit einer zusätzlichen wasserbeständigen Polymerhülle zu überziehen. Es wird zudem die Möglichkeit untersucht koaxial gesponnene Fasern nachträglich zu vernetzen, um so eine Wasserfestigkeit zu erzielen.
The electrolytic in situ generation of oxidants is an increasingly widespread technique for producing sanitized and thus safe process water in ultrapure water distribution systems. In particular, the anodic production of ozone on functionalized electrodes is a commercially available option for providing pharmaceutical-grade water. The present work therefore investigates the use of a newly developed electrolyzer with a polymer electrolyte membrane (PEM) and lead dioxide (PbO2) electrodes for drinking and ultrapure water treatment. The selective analysis of electrolytically generated oxidizing agents or reactive oxygen species such as ozone (O3), hydrogen peroxide (H2O2) and hydroxyl radicals (·OH) is often impeded by cross-sensitivities of commonly used photometric assays. To account for these imperfections, a step-by-step procedure to consolidate different analytical methods was developed. Depending on the applied current density, different electrolytically generated species can be detected selectively and enable the observation that the electrolytic generation of ozone only increases significantly for current densities above 0.5 A cm-2. In addition, the evolution of H2O2 only occurs in significant amounts in the presence of an organic impurity. The resulting, rapid decomposition of ozone via the peroxone process requires several equivalents of H2O2, depending on the present amount of dissolved O3.
In order to provide a sensitive in- or on-line detection for ozone in ultrapure water, electrode materials based on Pt-functionalized ionomers were developed using a modified impregnation-reduction process. The metal loading on the sensor material was determined satisfactorily using a non-destructive approach by means of computed tomography (CT). Different synthesis conditions led to different sensor properties in terms of sensitivity and applicable concentration range. After evaluation of different models by an objective information criterion, the potentiometric sensor behavior is best described by a Langmuir pseudo-isotherm. On average, 2.9 μg L-1 of dissolved ozone was found as the detection limit for all sensor materials produced, which is comparable to complex reference analysis.
Extending the application range for PEM electrolysis to the drinking water sector was evaluated by exposing the analytic feed to different water hardness levels. The electroosmosis of water is a direct function of the current density and can be estimated at 95 ± 2 mmol A-1 h-1. The transport rates of sodium, potassium, calcium and magnesium ions were modeled as a function of the current density and water hardness and were directly related to the ion mobility, independent of the water quality. Permeation leads to higher pH values of the catholyte within a few minutes and consequently to insoluble hydroxides and carbonates of the formerly dissolved hardeners. The introduction of an auxiliary cathode in the anode compartment was able to reduce tap water cation permeation indiscriminately by 18 ± 4 %.
The results show that the selected methods are suitable and directly applicable for the sensitive and selective detection of in situ produced disinfectants, in particular electrolytically generated ozone in the aqueous phase. An initial transfer of this PEM electrolyzer into the tap and drinking water environment is showcased the example of temporarily stagnant water with a constructive solution for suppressing unwanted ion crossover.
The success of any agent, human or artificial, ultimately depends on their successfully accomplishing the given goals. Agents may, however, fail to do so for many reasons. With artificial agents, such as robots, this may be due to internal faults or exogenous events in the complex, dynamic environments in which they operate. The bottom line is that plans, even good ones, can fail. Despite decades of research, effective methods for artificial agents to cope with plan failure remain limited and are often impractical in the real world. One common reason for failure that plagues agents, human and artificial alike, is that objects that are expected to be used to get the job done are often found to be missing or unavailable. Humans might, with little effort, accomplish their tasks by making substitutions. When they are not sure if an object is available, they may even proceed optimistically and switch to making a substitution when they confirm that an object is indeed unavailable. In this work, the system uses Description Logics to enable open-world reasoning --- making it possible to distinguish between cases where an object is missing/unavailable and cases where the failure to even generate a plan is due to the planner's use of the closed-world assumption (where the fact stating that something is true is missing from its knowledge base and so it is assumed to be not true). This ability to distinguish between something being missing and having incomplete information enables the agent to behave intelligently: recognising whether it should identify and then plan with a suitable substitute or create a placeholder, in the case of incomplete information. By representing the functional affordances of objects (i.e. what they are meant to be used for), socially-expected and accepted object substitutions are made possible. The system also uses the Conceptual Spaces approach to provide feature-based similarity measures that make the given task a first-class citizen in the identification of a suitable substitute. The generation of plans to `get the job done' is made possible by incorporating the Hierarchical Task Network planning approach. It is combined with a robust execution/monitoring system and contributes to the success of the robot in achieving its goals.