Gutenberg Open Science (Univ. Mainz)
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Magnetization switching driven by magnonic spin dissipation
No full textEfficient control of magnetization in ferromagnets is crucial for high-performance spintronic devices. Magnons offer a promising route to achieve this objective with reduced Joule heating and minimized power consumption. While most research focuses on optimizing magnon transport with minimal dissipation, we present an unconventional approach that exploits magnon dissipation for magnetization control, rather than mitigating it. By combining a single ferromagnetic metal with an antiferromagnetic insulator that breaks symmetry in spin transport across the layers while preserving the symmetry in charge transport, we realize considerable spin-orbit torques comparable to those found in non-magnetic metals, enough for magnetization switching. Our systematic experiments and comprehensive analysis confirm that our findings are a result of magnonic spin dissipation, rather than external spin sources. These results provide insights into the experimentally challenging field of intrinsic spin currents in ferromagnets, and open up possibilities for developing energy-efficient devices based on magnon dissipation
Unveiling cell-type-specific microRNA networks through alternative polyadenylation in glioblastoma
No full textBackground
Glioblastoma multiforme (GBM) is characterized by its cellular complexity, with a microenvironment consisting of diverse cell types, including oligodendrocyte precursor cells (OPCs) and neoplastic CD133 + radial glia-like cells. This study focuses on exploring the distinct cellular transitions in GBM, emphasizing the role of alternative polyadenylation (APA) in modulating microRNA-binding and post-transcriptional regulation.
Results
Our research identified unique APA profiles that signify the transitional phases between neoplastic cells and OPCs, underscoring the importance of APA in cellular identity and transformation in GBM. A significant finding was the disconnection between differential APA events and gene expression alterations, indicating that APA operates as an independent regulatory mechanism. We also highlighted the specific genes in neoplastic cells and OPCs that lose microRNA-binding sites due to APA, which are crucial for maintaining stem cell characteristics and DNA repair, respectively. The constructed networks of microRNA-transcription factor-target genes provide insights into the cellular mechanisms influencing cancer cell survival and therapeutic resistance.
Conclusions
This study elucidates the APA-driven regulatory framework within GBM, spotlighting its influence on cell state transitions and microRNA network dynamics. Our comprehensive analysis using single-cell RNA sequencing data to investigate the microRNA-binding sites altered by APA profiles offers a robust foundation for future research, presenting a novel approach to understanding and potentially targeting the complex molecular interplay in GBM
Die Expressionen der HDACs der Klasse I in humanen Odontoblasten der gesunden und durch Karies entzündlich veränderten Dentin-Pulpa-Einheit
No full textIn der vorliegenden Dissertation wird die Expression der HDACs der Klasse I in gesunden und durch Karies entzündeten Odontoblasten untersucht, um Rückschlüsse auf deren Deacetylierungszustände zu ziehen. Dies ist für die Entwicklung neuer Therapiestrategien zur Behandlung von Karies von großer Bedeutung und wurde bisher noch nicht untersucht.
Zur Untersuchung der Protein-Expression von HDAC1, HDAC2, HDAC3 und HDAC8 in gesunden und entzündeten Odontoblasten wurden aufeinanderfolgende Schnitte von gesunden (n = 5) und kariösen (n = 6) humanen Molaren mittels der Avidin-Biotin-Peroxidase-Komplex-Methode analysiert. Die Färbungsintensität der Antikörper in den Zellkernen der Odontoblasten wurde mittels Densitometrie gemessen und statistisch ausgewertet.
Unter pathologischen Bedingungen wurde eine statistisch signifikante Zunahme der Expression von HDAC1 und HDAC2 in den Odontoblasten der entzündeten Dentin-Pulpa-Einheit beobachtet. Zwar induzieren kariöse Läsionen eine erhöhte Expression von HDAC3 in den Zellkernen und Fortsätzen der Odontoblasten, jedoch waren die Befunde statistisch nicht signifikant. Für HDAC8 konnte keine Immunreaktivität festgestellt werden.
Die signifikant starke Expression von HDAC1 und HDAC2 in den Zellkernen der entzündeten Odontoblasten lässt die Hypothese zu, dass HDAC1 und HDAC2 nach einer kariösen Läsion die transkriptionale Regulation der Gene zur Tertiärdentinbildung hemmen können. Die statistisch nicht signifikante Hochexpression von HDAC3 im Zytoplasma und im Zellkern der entzündeten Odontoblasten kann tendenziell auf eine inhibitorische Rolle von HDAC3 bei der Bildung der Tertiärdentinmatrix hindeuten. Die vorliegenden Ergebnisse zeigen, dass HDAC8 keinen Effekt auf die Regulation der Tertiärdentinmatrixbildung hat.
Auf Basis der in der Studie gewonnenen Ergebnisse könnten HDAC1-, HDAC2- und HDAC3-Inhibitoren bei der Behandlung von kariösen Läsionen eine Option darstellen, beispielsweise als Überkappungsmaterialien, um eine Tertiärdentinbildung zu induzieren.IV, 43 Seiten ; Illustrationen, Diagramm
Ventricular dispersion and repolarization in Marfan syndrome : a clinical analysis
No full textBackground:
Patients with Marfan syndrome (MFS) are at an increased risk of ventricular arrythmia (VA) and death.
Objective:
This retrospective observational study aimed to assess the role of electrocardiographic parameters of repolarization and dispersion in risk stratification.
Methods:
Baseline 12-lead electrocardiograms were obtained from consecutive patients with MFS treated at a tertiary care specialized outpatient clinic and from age- and sex-matched controls. In patients with MFS, we studied the association of established parameters of repolarization and dispersion with a combined primary end point of VA or all-cause mortality using Cox regression analysis.
Results:
A total of 89 patients with MFS (mean age 42 ± 14 years; 54 (61%) women) and 92 controls were included in the analysis. The mean QRS duration (97 ms vs 87 ms) was longer, and the mean corrected QT interval (411 ms vs 379 ms) and T-peak–T-end interval (67 ms vs 62 ms) were also longer in patients with MFS. During a median follow-up of 5.05 years (interquartile range 3.43–10.0 years), 11 patients with MFS (12%) had VA or died. In univariable analyses, male sex (hazard ratio [HR] 5.01; 95% confidence interval [CI] 1.051–23.87), history of atrial fibrillation (HR 9.51; 95% CI 2.51–36.01), larger left atrial volume (HR 1.35 per 10-mL increase; 95% CI 1.12–1.64 per 10-mL increase), and higher N-terminal pro–B-type brain natriuretic peptide levels (HR 1.05 per 100-pg/mL increase; 95% CI 1.03–1.07 per 100-pg/mL increase) were associated with the primary end point, but QRS duration, corrected QT interval, and T-peak–T-end interval or their derivatives were not associated with the primary end point.
Conclusion:
Electrocardiographic parameters of repolarization and dispersion are altered in patients with MFS, but their role in risk stratification may be limited
Ki-67 as a prognostic marker in squamous cell carcinomas of the vulva : a systematic review
Get PDFBackground/Objectives: To evaluate the prognostic impact of immunohistochemical ki-67 staining analysis regarding lymph node involvement and survival data (overall/progression-free survival) in squamous cell carcinoma of the vulva. Methods: A systematic literature search of English and German articles was conducted (PubMed, Embase, Scopus, Web of Science) from 1980 to December 2023, including the search terms “vulvar Neoplasms”, “vulvar cancer”, “vulvar carcinoma”, “vulvar tumor”, ”vulvar tumour”, “vulvar malignancy”, “vulvar malignant”, “ki-67”, “MIB-1”, “MIB1”, “proliferative index”, “proliferative activity”, “mitotic index”, and “mitotic count”. Study quality was assessed using a two-step “mixed-criteria” approach; to synthesize study results, a narrative summary is provided. Results: In total, 13 studies were included in this systematic literature review. In general, two distinct methods of staining interpretation could be retrieved: A “pattern-based” method, as well as a cell count-based method. Ten of the included studies examined the relationship between ki-67 and lymph node involvement, nine studies included survival data as a parameter of interest; and only five studies defined both groin lymph node metastasis and survival data as outcome variables. While nine out of ten studies found no statistically significant association between ki-67 staining and lymph node metastasis, five out of nine studies determined an association between ki-67 status and overall survival, especially when employing a “pattern-based” method of staining interpretation. Conclusions: The prognostic value of ki-67 staining in terms of survival data has been reported ambivalently and should be subject to future studies. Furthermore, we did not find convincing evidence of an association between ki-67 and lymph node involvement
Unveiling IRF4-steered regulation of context-dependent effector programs in CD4+ T cells under Th17- and Treg-skewing conditions
Get PDFThe transcription factor interferon regulatory factor 4 (IRF4) is crucial for the fate determination of pro-inflammatory T helper (Th) 17 and the functionally opposing group of immunomodulatory regulatory T (Treg) cells. However, the molecular mechanisms of how IRF4 steers diverse transcriptional programs in Th17 and Treg cells are far from being definitive. Here, we integrated data derived from affinity-purification and full mass-spectrometry-based proteome analysis with chromatin immunoprecipitation sequencing. This allowed the characterization of subtype-specific molecular programs and the identification of IRF4 interactors in the Th17/Treg context. Our data reveal that IRF4-interacting transcription factors are recruited to IRF composite elements for the regulation of cell-type-specific transcriptional programs as exemplarily demonstrated for FLI1, which, in cooperation with IRF4, promotes Th17-specific gene expression. FLI1 inhibition markedly impaired Th17 differentiation. The present “omics” dataset provides a valuable resource for studying IRF4-mediated gene regulatory programs in pro- and anti-inflammatory immune responses
Ramadan during pregnancy and the role of dietary intake for neonatal health in Kaduna, Northwestern Nigeria : a cross-sectional study
Get PDFBackground
Ramadan during pregnancy is associated with adverse offspring health outcomes. Recent evidence from Europe indicates that maternal diet during non-fasting hours might alleviate these effects. This study describes fasting, diet, and sleep habits among pregnant Muslims in Kaduna, Nigeria, and assesses impacts on neonatal health in this setting.
Methods
Between July 2023 and February 2024, we conducted 1814 interviews with women whose pregnancy overlapped with Ramadan 2023 in Kaduna, northwestern Nigeria (cross-sectional study). We used a structured questionnaire to collect data on fasting, diet and sleep during Ramadan, as well as maternal socio-demographic characteristics. In the analyses of birth outcomes, 1370 mother-newborn pairs were included. We performed multivariate regression analyses to evaluate associations between fasting and birth weight and gestational duration, as well as the interaction of fasting with maternal dietary intake and sleep patterns.
Results
More than 80% of the study participants fasted during pregnancy. Women who fasted had infants with lower birth weights than non-fasting participants (-90.38 g, 95% CI: -173.64 g to -6.12 g). No independent associations were detected between reduced sleep and food intake, and birth weight. Fasting was not associated with gestational duration. Negative effects of fasting on birth weight were consistently concentrated among participants who reduced their dietary or fluid intake during Ramadan.
Conclusions
Dietary intake during non-fasting hours might mitigate potential adverse effects of Ramadan fasting on birth weight. With more than 25% of the global population adhering to Islam, this study highlights the need for additional research on Ramadan during pregnancy across different settings
Morphometrische Analyse des Nervus abducens in der petroclivalen Region
Get PDF43 Seiten ; Illustrationen, Diagramm
Klinische Evaluation des Multiplex-PCR-Systems BIOFIRE® SPOTFIRE® im Kontext von Infektionserkrankungen pädiatrischer Patienten
Get PDFDissertationsschrift zu einer unizentrischen, prospektiven Vergleichsuntersuchung eines experimentellen Multiplex-PCR-Systems gegenüber einem klinischen Standardverfahren in einem infektiologisch- pädiatrischen Patientenkollektiv.V, 105 Seiten ; Illustrationen, Diagramm
The creation of virtual scenes and their realistic embedding in the real environment
Get PDFThe creation of virtual worlds has fascinated researchers for several decades. Advances in hardware have made it ever more feasible for the virtual and real worlds to merge seamlessly in the field of mixed reality (MR). This research field combines a wide range of disciplines, such as computer graphics, computer vision, machine learning, and physics. Despite great progress in the last decade, several challenges remain, particularly in achieving real-time performance on devices with limited hardware resources or in providing convincing visual quality with existing methods.
This thesis explores various aspects of MR and presents methods to improve the quality of applications in this domain. It includes a set of techniques for sampling the volume and surface of 3D objects using discrete points. Building on these techniques, a novel method for real-time simulation of granular materials with large particle numbers is introduced. By structuring the simulation in two stages, the method first simulates a small number of particles, including all acting forces. Subsequently, a larger number of particles are added for visualization, partially following the velocity field defined by the first stage. This approach allows for a more immersive experience in virtual reality applications where interactions with materials like sand or gravel are simulated, such as in heavy equipment operator training.
Moreover, this thesis focuses on improving the photometric registration of virtual objects in augmented reality applications. A method for analyzing the real-world lighting situation is presented, using geometric and photometric parameters derived from an RGB camera image with an artificial neural network. Furthermore, a novel method for the efficient visualization of soft cast shadows of virtual objects is introduced. In this approach, shadow textures are encoded within tiny artificial neural networks, which can be queried based on the current lighting situation to produce realistic shadows with minimal computational overhead.x, 173 Seiten ; Illustratione