14043 research outputs found
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Characterization of a laser filament-induced plasma in air at 10 kHz using optical emission spectroscopy
No full textThe increasing availability of high-power Yb-based ultrafast laser-amplifier systems has opened the possibility of air filamentation at high repetition rates >1 kHz. In this new regime, accumulation effects cannot be ruled out; therefore, characterizing the plasma parameters and afterglow plasma-chemical kinetics becomes increasingly relevant. In this work, we use optical emission spectroscopy to measure nanosecond dynamics of gas temperature and electron temperature, species-specific decay times, and electron density of an atmospheric air laser filament produced by a high-average power femtosecond laser at a high repetition rate of 10 kHz. The molecular excitation mechanisms behind the nitrogen photoemissions are derived from vibrational distributions and temporal behavior of the studied emission bands. The presented diagnostic technique offers a complementary but more holistic measurement approach to optical probe schemes to characterize the laser-filament-induced plasma wake for high repetition rate filaments
Die Parkinson-Komplextherapie im Fokus
No full textDie Parkinson-Komplextherapie (PKT) ist in Deutschland weit verbreitet und hat das Ziel, die Lebensqualität und Aktivitäten des täglichen Lebens (ADL) von Menschen mit Parkinson-Krankheit (PK) zu verbessern. Dabei können sensorbasierte Ganganalysen zu einer individualisierten Therapie beitragen. Ziel dieser explorativen Kohortenstudie ist, Prädiktoren für einen Benefit hinsichtlich der ADL unter Berücksichtigung von Gangparametern und klinischen Scores zu identifizieren und einen Prä-Post-Vergleich durchzuführen. Dazu wurden klinische Scores und sensorbasierte Gangparameter von 56 Personen mit PK zu Beginn und Ende der PKT erhoben. Mittels eines binomialen logistischen Regressionsmodells konnten als Prädiktoren für eine wahrgenommene Verbesserung der ADL ein jüngeres Alter, eine höhere initiale Einschränkung der ADL, eine bessere feinmotorische Funktion sowie ein konstantes Gangbild identifiziert werden
Establishing a real-time biomarker-to-LLM interface
No full text Large language models are capable of summarizing research, supporting clinical reasoning, and engaging in coherent conversations. However, their inputs are limited to user-generated text, which reflects subjective reports, delayed responses, and consciously filtered impressions. Integrating physiological signals provides a clear additional value, as it allows language models to consider real-time indicators of autonomic state alongside linguistic input, thereby enabling more adaptive and context-sensitive interactions in learning, decision-making, and healthcare. Therefore, we present a streamlined architecture for routing real-time heart rate variability data from a wearable sensor directly into a generative AI environment.
Using a validated heart rate variability sensor, we decoded Bluetooth-transmitted R-R intervals via a custom Python script and derived core heart rate variability metrics (HR, RMSSD, SDNN, LF/HF ratio, pNN50) in real time. These values were published via REST and WebSocket endpoints through a FastAPI backend, making them continuously accessible to external applications—including OpenAI's GPT models.
A live data pipeline from autonomic input to conversational output. A language model that does not just talk back, but responds to real-time physiological shifts in natural language. In multiple proof-of-concept scenarios, ChatGPT accessed real-time HRV data, performed descriptive analyses, generated visualizations, and adapted its feedback in response to autonomic shifts induced by low and high cognitive load.
This system represents an early prototype of bioadaptive AI, in which physiological signals are incorporated as part of the model's input context
Standardizing the C-methacetin breath test
No full textBackground/Objectives:
The C-Methacetin Breath Test (MBT) is a non-invasive tool to evaluate hepatic microsomal function via exhaled CO, reflecting cytochrome P450 1A2 (CYP1A2)-mediated metabolism. Despite decades of evidence demonstrating its utility in diagnosing cirrhosis, stratifying liver disease severity, and predicting outcomes, MBT adoption remains limited due to methodological inconsistencies and variable diagnostic thresholds. This review aimed to summarize MBT data in adults and assess its diagnostic and prognostic performance.
Methods:
A literature review was conducted using PubMed, Web of Science, and Scopus. Eligible studies included those applying oral or intravenous methacetin with defined reference values or diagnostic cutoffs. Outcomes of interest were percent dose recovery (PDR), cumulative PDR (cPDR), and LiMAx® values. Due to heterogeneity in protocols, units, and endpoints, results were synthesized narratively.
Results:
Healthy individuals typically demonstrated rapid metabolism (e.g., cPDR30 10–15%), whereas cirrhotic patients showed significantly reduced values (e.g., cPDR30 1%). Diagnostic cutoffs varied widely (<0.35% to <8%), reflecting methodological and population differences. MBT reliably identified advanced liver disease but showed inconsistent sensitivity for early-stage fibrosis and metabolic dysfunction-associated steatotic liver disease. Variability in dosing, timing, measurement duration, and analytic technique limited cross-study comparability.
Conclusions:
MBT is a validated, dynamic marker of liver function with both diagnostic and prognostic relevance. However, inconsistent protocols and thresholds hinder its clinical implementation. Standardization of MBT procedures, reference ranges, and reporting metrics is essential. A harmonized protocol ("MBT-60"), supported by multicenter validation, demographic stratification, and direct comparison with structural and serologic liver tests, is recommended to facilitate MBT integration into routine hepatology practice
A new fundamental mixture model for hydrogen+water mixtures and application to hydrate modeling
No full textMultimode vertical-cavity surface-emitting lasers under spin injection
No full textRecent research revealed that single-mode vertical-cavity surface-emitting lasers under spin injection (spin-VCSELs) have the potential to revolutionize laser technology for short-haul optical communications. While previous studies have focused solely on single-mode operation, this study introduces multimode spin-VCSELs. We experimentally demonstrate the existence of multi-resonant polarization dynamics when spin is injected, a phenomenon previously unobserved. The development opens the door to significantly faster and more efficient optical communication systems by harnessing the collective behavior of multiple laser modes. Furthermore, we lay the groundwork for understanding multimode operation through the extension of the single-mode spin–flip model, which forms the basis for present and future analyses of multimode spin-laser operation. This work is an important step toward realizing the full potential of spin-VCSELs and, thus, enables significantly improved performance of spin-VCSEL-based optical networks in the future
The transcriptome of the olm provides insights into its evolution and gene expression
No full textThe olm (), with a predicted maximum lifespan of more than 100 years, is the longest-lived amphibian, which in addition possesses a range of unique adaptations to its dark, subterranean cave habitat. To assess the underlying molecular signatures, we present the first comprehensive transcriptome of the olm. Our study provides gene expression data across six organs and comparative genomics analyses, accessible via an interactive web server: http://comp-pheno.de/olm. The data uncover significant organ-specific gene expression, with the brain showing the highest number of organ-specific expressed genes. Our findings reveal significantly more genes under strong negative selection than positive selection, particularly in brain-specific expressed genes. Processes under positive selection in the olm resemble those in other long-lived species
BUILT
No full textDer Katalog erschien anlässlich der Ausstellung von Michael Cleffs Arbeiten im März 2023 in der Galerie Geißler Bentler in Bonn. Er enthält Fotos von plastischen Arbeiten und Installationen aus den Jahren 2017 bis 2023.
In den Texten "Gebaut" und "Ausweitung der Randzone" besprechen Gabriele Uelsberg und Roland Mönig die Werke und ordnen Michael Cleffs Schaffen kunsthistorisch ein.
Dieser Katalog erscheint anlässlich der Ausstellung:
Michael Cleff
BUILT
Galerie Geißler Bentler, Bonn
24. März – 06. Mai 2023
www.geissler-bentler.d
Enhanced superconductivity in compounds via hole-Doping at ambient pressure
No full textThis study presents a computational investigation of compounds (where X represents a metal) as potential superconductors at ambient conditions or under pressure. Through systematic density functional theory calculations and electron–phonon coupling analysis, it is demonstrated that electronic structure engineering via hole doping dramatically enhances the superconducting properties of these materials. While electron-doped compounds with X cations (Ti, Zr, Hf, Th) exhibit modest transition temperatures of 1–9 K, hole-doped systems with X cations (Y, Tb, Dy, Ho, Er, Tm, Lu) show remarkably higher values of 50 K at ambient pressure. Superconductivity in hole-doped compounds originates from stronger coupling between electrons and both cation and hydrogen phonon modes. Although pristine compounds are thermodynamically unstable, a viable synthesis route via controlled hole doping of the charge-compensated YZr compound is proposed. The calculations predict that even minimal concentrations of excess Y can induce high-temperature superconductivity while preserving structural integrity. This work reveals how strategic electronic structure modulation can optimize superconducting properties in hydride systems, establishing a promising pathway toward practical high-temperature conventional superconductors at ambient pressure