Gutenberg Open Science (Univ. Mainz)
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Retention during freezing of raindrops – Part 2 : Investigation of ambient organics from Beijing urban aerosol samples
Get PDFThe freezing of hydrometeors causes certain water-soluble organic compounds dissolved in the supercooled cloud droplets to be released into the gas phase. This may lead to the vertical redistribution of substances that become available for atmospheric processes in the upper troposphere, such as new particle formation or ozone formation. Drop-freezing experiments were performed on the Mainz acoustic levitator (M-AL) using aqueous extracts of ambient samples of Beijing urban aerosol. The retention coefficients of over 450 compounds were determined. Most nitro-aromatics and organosulfates were fully retained, along with the aliphatic amines (AAs) and higher-order amines and amides, while the observed sulfides, lipids, aromatic hydrocarbons, and long-chain compounds are among the most unretained and, incidentally, are the fewest species present. The findings here also indicate that N- and S-containing compounds, primarily nitro and sulfate components of secondary organic aerosols (SOAs) anthropogenically related to NOx and SO2 chemistry, have enhanced retention, likely due to their increased polarity. An insignificant positive correlation between polarity and freezing retention, along with a significant negative correlation with vapor pressure and freezing retention, was observed. No sigmoidal relationship with the effective Henry's law constant was observed. This differs from the parameterizations of riming retention presented in the current literature, which is justified by the lower surface-to-volume ratio of the large drop size investigated. This study greatly expands upon the available experimental measurements of retention by investigating hundreds of compounds in complex chemical conditions that are more similar to the atmosphere than in previous literature studies
PhyLiNO: a forward-folding likelihood-fit framework for neutrino oscillation physics
Get PDFWe present a framework for the analysis of data from neutrino oscillation experiments. The framework performs a profile likelihood fit and employs a forward-folding technique to optimize its model with respect to the oscillation parameters. It is capable of simultaneously handling multiple datasets from the same or different experiments and their correlations. The code of the framework is optimized for performance and allows for convergence times of a few seconds handling hundreds of fit parameters, thanks to multi-threading and usage of GPUs. The framework was developed in the context of the Double Chooz experiment, where it was successfully used to fit three- and four-flavor models to the data, as well as in the measurement of the energy spectrum of reactor neutrinos. We demonstrate its applicability to other experiments by applying it to a study of the oscillation analysis of a medium baseline reactor experiment similar to JUNO
On the deposition mechanism and irradiation behaviour of molecular plating thin films
Get PDFSuperheavy elements are produced by heavy ion fusion reactions using intense beams that irradiate suitable targets. For the heaviest elements, lead/bismuth and actinide targets are primarily used for this purpose. The production of actinide targets has been mainly based on the molecular plating (MP) method for decades.
The MP method is also widely used in the preparation of actinide and lanthanide samples for other research areas. The mechanism of the MP process has not yet been conclusively elucidated. The majority of work on the subject is limited to morphological studies. Spectroscopic studies have been limited to X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). The reason for this limited spectroscopic data situation is to be found in the special challenges arising from the radioactivity of the actinide samples. Technical restrictions and legal requirements thus prevent access to modern methods, as the relevant laboratories lack the clearance to handle radioactive material. Besides radioactivity, high costs in acquisition and disposal prevent mass experiments, e.g. to optimise electrochemical parameters. Therefore, it is common to limit oneself to experiments on lanthanide samples. The present work was also limited to lanthanide samples, but radioactive tracers could be generated using the Mainz research reactor TRIGA Mark II. In this way, short-lived lanthanide isotopes were used to test working methods and analytical procedures that can also be transferred to future procedures with actinides. The electrochemical production of actinide targets is virtually limited worldwide to the MP process and some closely related methods. Developments in the technically more important field of lanthanide electrochemistry have not been transferred to target production. Thus, the established MP method is still limited by significant deposition of unwanted by-products and thus low maximum deposition rates of desired actinides.
When MP films are irradiated at the heavy ion accelerator, changes in the alpha spectra of the irradiated actinide thin films are a clear spectroscopic indication of chemical changes due to irradiation. Photographs taken before and after the accelerator experiments provide evidence of drastic morphological changes, which has been confirmed by some initial publications on lanthanide substitutes, using scanning electron microscopy (SEM). By understanding the chemical processes involved, it is hoped to improve the quality and stability of the MP targets used.
This dissertation presents two publications on mechanistic studies of lead and lathanide targets, presenting new insights into the MP process and the irradiation behaviour of the thin films. The third publication attempts to adapt established new methods for the electrochemical deposition of lanthanides to the needs of target production and to present the first irradiation tests with these thin films.Superschwere Elemente werden durch Schwerionen-Fusionsreaktionen unter Verwendung intensiver Strahlen, welche geeignete Targets bestrahlen, erzeugt. Bei den schwersten Elementen werden dazu vor allem Blei/Bismut und Actiniden-Targets eingesetzt. Die Produktion von Actiniden-Targets beruht seit Jahrzehnten hauptsächlich auf der Methode des Molecular Plating (MP).
Das MP Verfahren findet auch bei Präparation von Actiniden- und Lanthaniden-Proben für andere Forschungsgebiete breite Anwendung. Der Mechanismus des MP Verfahrens ist noch nicht abschließend aufgeklärt. Die Mehrheit der Arbeiten zum Thema beschränkt sich auf morphologische Studien. Spektroskopische Studien beschränkten sich bisher auf die Röntgenphotoelektronenspektroskopie (XPS) und die Energiedispersive Röntgenspektroskopie (EDX). Die Ursache für diese eingeschränkte spektroskopische Datenlage ist in den besonderen Herausforderungen zu suchen, die sich aus der Radioaktivität der Actiniden-Proben ergeben. Technische Einschränkungen und gesetzliche Vorgaben verhindern so den Zugriff auf moderne Methoden, da den entsprechenden Laboren die Freigabe für den Umgang mit radioaktivem Material fehlt. Neben der Radioaktivität verhindern hohe Kosten in der Anschaffung und Entsorgung Massenexperimente, um z.B. elektrochemische Parameter zu optimieren. Daher ist es üblich sich auf Experimente an Lanthaniden-Proben zu beschränken. Auch in der vorliegenden Arbeit wurde sich auf Lanthaniden-Proben beschränkt, jedoch konnten mittels des Mainzer Forschungsreaktors TRIGA Mark II radioaktiven Tracer erzeugt werden. So konnten anhand von kurzlebigen Lanthaniden-Isotopen Arbeitsweisen und Analyseverfahren erprobt werden, die sich auch auf zukünftige Verfahren mit Actiniden übertragen lassen. Die elektrochemische Herstellung von Actiniden-Targets ist weltweit quasi auf das MP Verfahren und einige engverwandte Methoden beschränkt. Entwicklungen auf dem technisch wichtigeren Gebiet der Elektrochemie der Lanthanide, wurden für die Target Herstellung nicht übertragen. So ist das etablierte MP Verfahren immer noch durch signifikante Abscheidungen von unerwünschten Nebenprodukten und damit geringen maximalen Abscheidemengen an gewünschten Actiniden eingeschränkt.
Bei der Bestrahlung von MP Filme am Schwerionenbeschleuniger, sind Veränderungen der alpha-Spektren der bestrahlten Actiniddünnfilme ein deutlicher spektroskopischer Hinweis auf chemische Veränderungen durch Bestrahlung. Fotos vor und nach den Beschleunigerexperimenten geben Hinweis auf drastische morphologische Veränderungen, was einige erste Publikationen an Lanthanidsubstituten, mittels Rasterelektronenmikroskopie (REM), bestätigt haben. Durch Verständnis der ablaufenden chemischen Prozesse, erhofft man sich Verbesserungen in der Qualität und Stabilität der verwendeten MP Targets.\\
Die vorliegende Arbeit präsentiert zwei Publikationen zu mechanistischen Studien an Blei- und Lathanidtargets, in denen neue Erkenntnisse zum MP Verfahren und zum Bestrahlungsverhalten der Dünnfilme präsentiert werden. Die dritte Publikation versucht etablierte neue Verfahren zur elektrochemischen Abscheidung von Lanthaniden, an die Bedürfnisse der Targetherstellung anzupassen, sowie erste Bestrahlungstests mit diesen Dünnfilmen zu präsentieren.161 Seiten ; Illustrationen, Diagramm
The MCL elderly III trial protocol: an international, randomized, open-label phase II trial to investigate the combinations of venetoclax, ibrutinib and rituximab or bendamustine, ibrutinib and rituximab in patients with treatment naive mantle cell lymphoma not eligible for dose-intensive treatment
Get PDFBackground
Mantle cell lymphoma (MCL) is a rare B-cell Non-Hodgkin-lymphoma that predominantly affects elderly patients. While younger and fit patients receive an intensive first-line treatment, older or comorbid patients have limited options of chemo-immunotherapy (CIT) alone followed by anti-CD20-antibody maintenance. Targeted oral agents as Bruton`s tyrosine kinase inhibitors (BTKi, e.g. ibrutinib) - and B-cell lymphoma 2 (Bcl2) – inhibitors (e.g. venetoclax) have revolutionized the treatment especially for relapsed patients, with apparent synergistic effects. The MCL elderly III trial of the European MCL Network is an international phase II trial evaluating the efficacy of the combination of ibrutinib, venetoclax and rituximab as well as the CIT bendamustine and rituximab in combination with ibrutinib in elderly patients with untreated MCL.
Methods
The primary trial objective is to evaluate efficacy in both treatment arms as measured by failure-free survival at 30 months separately in both treatment arms. Secondary endpoints include progression-free survival, response rates, overall survival, adverse events as well as quality of life and impact of frailty and sarcopenia on treatment outcome through geriatric and body composition assessments via imaging. Exploratory endpoints comprise the rate of minimal residual disease negativity and kinetics of immune reconstitution.
Current status
The first patient was included in May 2023, with full site activation achieved in Q1 2025. Until May 15th 2025, 75 of 150 planned patients were enrolled in 27 German and Italian trial sites.
Discussion
This is the first randomized trial to exploratively compare a BTKi-Bcl2i-anti-CD20 triplet to a BTK-CIT combination in older MCL patients.
Trial registration
The trial is registered on EU Clinical Trial Register (20225018089600)
The impact of healthcare provision on immigrant pregnancy behaviors : the case of Ramadan fasting in Germany
Get PDFGermany and other Western countries are home to a growing number of Muslims. This implies that health-related behaviors more common among Muslims are becoming increasingly important in routine healthcare. For example, Ramadan during pregnancy has been shown to be associated with adverse offspring health outcomes along the life course. At the same time, a high share of pregnant Muslims worldwide chooses to fast. In this study, we investigate the dynamics underlying Ramadan fasting during pregnancy in Germany, using survey data (N=326) of Muslims delivering after being pregnant during a Ramadan. In this sample, 36.5 % of women fasted during their recent pregnancy, for an average of 17 days. Respondents generally did not regard fasting during pregnancy as obligatory and women tended to make their own, independent decisions about whether to fast. Most women did not expect fasting to be associated with impaired offspring health, even though many women actively searched for information on Ramadan during pregnancy. They often did so on the internet or by talking to family and friends. Only about one-third of women consulted with their prenatal caregiver about fasting. These consultations were associated with a reduction in days fasted by about 11 days. A sensitization of healthcare providers to Ramadan during pregnancy, and routinely addressing the issue with Muslim families of reproductive age can have important public health benefits
Ultrafast dynamics of chiral spin structures in synthetic antiferromagnets
Get PDFIn synthetic antiferromagnetic multilayers (SAFs), chiral magnetic structures such as spin spirals and skyrmions have been stabilized at room temperature by precisely tuning the effective perpendicular magnetic anisotropy, the Dzyaloshinskii-Moriya interaction, and the Ruderman-Kittel-Kasuya-Yoshida (RKKY) interlayer coupling. In this study, we investigate the dynamics of spin spirals on ultrashort timescales after femtosecond laser pumping in SAFs. The access to ultrafast magnetization dynamics, inaccessible by conventional optical techniques due to the zero net magnetization, has been enabled by the use of time-resolved circular dichroism in x-ray resonant magnetic scattering (CD-XRMS). A pair of two-dimensional x-ray scattering patterns for left and right elliptical polarization (EL and ER) have been recorded for each delay. In contrast to our previous findings in ferromagnetic multilayers, the magnetization (EL+ER) and dichroism (EL−ER) signals exhibit notably similar ultrafast dynamics, with demagnetization occurring on a timescale of ∼180 fs, followed by rapid remagnetization within ∼500 fs. This similarity in ultrafast dynamics can be attributed to the continuous rotation of magnetization in the spin spiral of SAFs, which evolves smoothly in space without forming abrupt domains or alternating domain walls. The ultrafast response and stability in its topological character highlight the potential of SAF-based chiral magnetic structures for future high-speed, energy-efficient data storage and processing applications
Schwierigkeiten in der Emotionsregulation - eine Kreuzvalidierungsstudie
Get PDFIV, 72 Seiten ; Illustratione
A New Lagrangian Perspective on Atmospheric Heat Extremes
Get PDFHeat extremes are among the most dangerous weather-related hazards. However, a full understanding of how heat extremes form in the Earth’s atmosphere is still lacking.
In particular, the relative importance of the three key processes—horizontal advection, subsidence, and diabatic heating—is a subject of ongoing debate. This thesis provides a new quantitative assessment on the relative importance of these processes employing the Lagrangian framework. A key aspect of this new assessment is the consideration of a Lagrangian climatology of the processes. The assessment reveals that horizontal advection can be seen as the main contributor to heat extremes across most of the globe.
In the first part of the thesis, a new method for extracting Lagrangian information about the atmospheric flow is developed, which is later used to quantify the key processes
of heat extreme formation. The method is based on the advection of passive tracer fields in combination with a relaxation term. As a result, the method provides accumulated
Lagrangian information, such as the recent diabatic heating experienced by air parcels along their pathways, at each point on an Eulerian grid at any time step. The method
can be regarded as an alternative tool to calculating trajectories, tailored to gaining accumulated Lagrangian information efficiently.
In the second part of the thesis, the tracer method is then used to quantitatively assess the roles of the processes involved in heat extreme formation from a Lagrangian perspective.
At each grid point and time step, the method provides a decomposition of temperature anomalies into the aforementioned processes. Two different decomposition approaches are
contrasted: one that has been established in previous studies and which is based on the absolute contributions of the respective terms; and one that is introduced in this thesis
and that considers the contributions in terms of anomalies, defined as deviations from their corresponding climatological means. The new decomposition is based on the understanding
that a particularly large contribution from a given term may be irrelevant if it typically occurs as part of the climatology. By removing the atmosphere’s climatological behaviour—
which is of limited use in explaining anomalies—the new approach arguably provides a more meaningful framework for understanding anomalous temperatures. The analysis of two
recent heatwaves in the extratropics reveals that the new decomposition offers a markedly different perspective on the relative importance of the processes compared to previous
assessments of these cases. In particular, anomalous horizontal advection—specifically the absence of cold-air advection—rather than anomalous subsidence or diabatic heating, is
found to be the key contributor to heat extremes in the studied regions.
In the final part of the thesis, the region-specific findings are extended to encompass the entire global domain. Most importantly, the analysis reveals that the contribution from anomalous horizontal advection dominates the formation of near-surface heat extremes across the entire midlatitude region.
The presented Lagrangian diagnostic, together with the newly developed tracer method, could be readily applied to climate model simulations, providing a powerful tool to deepen
our understanding of the processes driving heat extremes in a future climate, where they are likely to pose an even greater threat to society than today.115 Seiten ; Illustrationen, Diagramm
Infinite boredom : generative AI as template culture
Get PDFStandardized practices and phenomena are integral to the field of generative AI, and this is particularly evident in the domain of generative imagery. These tendencies extend beyond mere aesthetics, as the act of "prompting" in AI systems is itself a process that relies heavily on standardization. Generative AI systems, while seemingly innovative, merely replicate existing norms and templates in visual culture, thus reproducing what has been standardized
Hyperaktivierung humaner T-Zellen durch neutrophile Granulozyten unter Arginaseinhibition
Get PDFIm TME wirken unterschiedlichste Mechanismen immunsuppressiv und hemmen vor allem T-Zellen in ihren antitumoralen Funktionen und Eigenschaften. Diese umfassen die Induktion und Rekrutierung von MDSCs, die Expression von hemmenden Rezeptoren, die Reduktion von Nährstoffen und Sauerstoff und somit veränderte metabolische Bedingungen für T-Zellen, die Sekretion von hemmenden Zytokinen oder ROS und die Arginase-vermittelte Depletion von der für die T-Zellaktivierung essenziellen Aminosäure Arginin. Diese vielfältigen immunsuppressiven Mechanismen machen deutlich, dass Tumor(immun)therapie vielfältig sein muss, um die Funktion von T-Zellen auf unterschiedlichste Weise zu unterstützen und zu verbessern. Ein bei konsekutiver Hemmung der Arginase-induzierten Arginin-Depletion gewonnener Überstand humaner PMN (PMN-ÜS) wirkt dagegen auf aktivierte T-Zellen sehr stark stimulierend, wie unserer Arbeitsgruppe erstmals gezeigt hatte.
In der hier vorliegenden Arbeit wurden verschiedene zentrale Aspekte dieser so hyperaktivierten T-Zellen detailliert untersucht. Diese T-Zellen zeigten eine deutliche Differenzierung hin zu effizienten antitumoralen T-Zellphänotypen wie TCM und naiven CD28+CD57- T-Zellen. Dies zeigte sich nicht nur in T-Zellen gesunder Spender, sondern auch in anergen und seneszenten T-Zellen aus dem Knochenmark und peripheren Blut von Patienten mit Multiplen Myelom, die bei Aktivierung in PMN-ÜS stark proliferieren können. Die Hyperaktivierung humaner T-Zellen war assoziiert mit einem gesteigerten Metabolismus, sowohl von Glykolyse als auch von oxidativer Phosphorylierung, vermehrter Glukose-Aufnahme sowie einem Kinase-Profil, welches mit einer gesteigerten Protein-Translation assoziiert ist. Auch konnte eine verstärkte Degranulation, ein Grundpfeiler effektiver Zytotoxizität, in den T-Zellen induziert werden. Hyperaktivierte T-Zellen zeigten eine bessere Viabilität in Langzeitkultivierungen und auch nach wiederholter peptidspezifischer Restimulation eine höhere antitumorale Zytotoxizität. Durch die PMN-induzierte Hyperaktivierung erlangen T-Zellen also Eigenschaften, die sie vermutlich deutlich effektiver in ihren antitumoralen Funktionen auch in vivo machen.
Ein Großteil der neu entwickelten Tumortherapien basiert auf der Aktivierung des T-Zell-Kompartiments im Immunsystem. Für ICI, CAR-T-Zellen, TCR-T-Zellen, Tumorimpfungen oder bispezifische Antikörper liefern die, molekular noch nicht identifizierten, durch PMN sezernierten T-Zell stimulierenden Faktoren unter Arginaseinhibition genau die Art der vielfältigen T-Zellaktivierung, die in der zukünftigen Tumorimmuntherapie eine immer größere Rolle spielen wird.174 Seiten ; Illustrationen, Diagramm