Scientific publications of the Saarland University
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Adult ADHD predicts intimate partner violence perpetration and victimization irrespective of gender and age
Full text linkUnderstanding the determinants of intimate partner violence (IPV) from perpetrator and victim
perspectives has become a major objective of behavioral science. Empirical evidence suggests
that adults at risk for Attention-Deficit/Hyperactivity Disorder (ADHD), compared to the general
population, tend to have more conflictual partnerships, and the presence of ADHD increases the risk
of aggressive behavior. Possible influences of gender have not been sufficiently investigated yet.
Using data from an anonymous online survey, this study examined the relationship between ADHD
and IPV in 316 male and female individuals with (n = 131) and without (n = 185) ADHD. Multiple linear
regression analyses showed that adults at risk for ADHD had more frequently become both victims and
perpetrators of IPV compared to the healthy control group. ADHD achieved significant incremental
variance over gender and age. Thus, the presence of ADHD seems to be an important risk factor for IPV
irrespective of gender and age. Accordingly, research and treatment approaches focusing on ADHD
must not neglect the risk of IPV among patients but should offer specific psychological support
Oligodendrocyte precursor cells facilitate neuronal lysosome release
Full text linkOligodendrocyte precursor cells (OPCs) shape brain function through many
non-canonical regulatory mechanisms beyond myelination. Here we show that
OPCs form contacts with their processes on neuronal somata in a neuronal
activity-dependent manner. These contacts facilitate exocytosis of neuronal
lysosomes. A reduction in the number or branching of OPCs reduces these
contacts, which is associated with lysosome accumulation and altered metabolism in neurons and more senescent neurons with age. A similar reduction in
OPC branching and neuronal lysosome accumulation is seen in an early-stage
mouse model of Alzheimer’s disease. Our findings have implications for the
prevention of age-related pathologies and the treatment of neurodegenerative
diseases
Alternative Dispute Resolution in the Western Balkans : Trends and Challenges
Full text linkAlternative Dispute Resolution (ADR) is increasingly recognized as an attractive alternative to national court proceedings, especially in international business relations. This open access book focuses on ADR mechanisms in one specific geographical region: the Western Balkans. This region comprises Albania, Bosnia and Herzegovina, Croatia, North Macedonia, Montenegro, Kosovo, and Serbia. Although these countries generally have legal frameworks for ADR mechanisms in place, they remain largely underutilised in practice. Promoting ADR mechanisms in the countries of the Western Balkans could make them more attractive to foreign investors, thereby fostering economic growth. Additionally, the effective implementation of ADR mechanisms could have spill-over effects on national judiciaries, thereby increasing domestic rule of law standards. This would be highly beneficial for the Western Balkan countries, most of which are still aspiring to become Member States of the European Union (EU). To achieve this, they are required to promote the use of ADR mechanisms and align their legal frameworks with EU standards.
Against this background, this book aims to explore the trends and challenges of ADR in the Western Balkans. The different chapters primarily focus on international commercial arbitration, investment treaty arbitration, and mediation. Some chapters address systemic challenges, such as capacity building and dispute prevention, which extend to the entire region. Others offer country-specific analyses of particular national framework. While some chapters adopt the perspective of international or EU law, others remain at the national level. Collectively, the wide diversity in topics and perspectives provides a comprehensive overview of the trends and challenges of ADR mechanisms in the Western Balkan.German Ministry for Education and Researc
How Valid Is Bandura’s Social Cognitive Theory to Explain Physical Activity Behavior?
Full text link(1) Background: Although social cognitive theory (SCT) has been widely tested
and applied in numerous interventions aimed at optimizing physical activity behavior, the
complete theory has rarely been tested in its entirety. Only selected elements have been
tested, and specific samples, some of them pathological, have been studied rather than the
general population, for whom a lack of physical activity is a huge problem. The present
study addresses these two research gaps and tests the tenability of the theoretical assumptions of SCT to explain physical activity behavior in the general population. (2) Methods: A
total of 194 German adults (109 male, 85 female) with a mean age of 26.03 years (SD = 10.33)
completed two validated questionnaires concerning their expressions on SCT components
(t1) and their physical activity (t2). SCT was modeled using a structural equation model
with latent variables. (3) Results: The results showed the very good fit of the structural
model, indicating that the theoretically stated relations between the constructs in SCT
seem to be corroborated, despite some paths seeming to be more important than others.
(4) Conclusions: The use of SCT to explain and predict behavior can be seen as justified,
even though it once again appears that some aspects (i.e., self-efficacy) are more crucial
than others
Association of Homocysteine, S-Adenosylhomocysteine and S-Adenosylmethionine with Cardiovascular Events in Chronic Kidney Disease
Full text linkBackground: Patients suffering from chronic kidney disease (CKD) have a high
risk of premature cardiovascular morbidity and mortality. It has been suggested that elevated homocysteine (Hcy) or disturbances in the transmethylation pathway may contribute
to this high cardiovascular risk burden due to epigenetic mechanisms. The objective of this
study was to explore the prognostic value of Hcy, S-adenosylhomocysteine (SAH) and Sadenosylmethionine (SAM) (one-carbon (C1)-metabolites) among patients with CKD. Methods: Plasma concentrations of Hcy, SAM and SAH were measured among 297 participants
with CKD (KDIGO GFR category G2–G5). The predefined endpoint was the occurrence of
major cardiovascular events (MACE), defined as carotid, coronary and peripheral arterial
revascularization, stroke, acute myocardial infarction, major amputation, cardiovascular
death and all-cause mortality during a median (IQR) follow-up period of 4.0 [3.2; 4.3] years.
Results: Among all participants, the median (IQR) of plasma Hcy, SAH, and SAM levels
were 16.6 [13.5; 21.2] µmol/L, 41.5 [26.6; 63.9] nmol/L, 183.4 [151.1; 223.5] nmol/L, respectively. Estimated glomerular filtration rate (eGFR) correlated more strongly with plasma
SAH (r = −0.588) than with SAM (r = −0.497) and Hcy (r = −0.424). During the follow-up
period, 55 participants experienced MACE. In a univariate Kaplan Meier analysis, all three
C1-metabolites were significantly associated with the occurrence of the primary outcome.
In a Cox-regression analysis, the association between Hcy and MACE was not significant
after adjustment for age and sex (hazard ratio (HR) and 95% confidence intervals (95% CI)
for the 3rd vs. 1st tertile = 1.804 (0.868–3.974)). Both SAH and SAM were not associated
with MACE after adjustment for age, sex and additionally for renal function markers (SAH:
HR 3rd vs. 1st tertile 1.645 95% (0.654–4.411); SAM: HR 3rd vs. 1st tertile 1.920 95% CI
(0.764–5.138)). Conclusions: In people with CKD, plasma Hcy, SAH and SAM were not
independent predictors of MACE after adjustment for age, sex and renal function. Disturbed renal function may explain elevated C1-metabolites and disturbed transmethylation,
while this pathway is not likely to be an appropriate access point to modify the risk of
cardiovascular events in CKD patients
Revolutionizing MASLD: How Artificial Intelligence Is Shaping the Future of Liver Care
Full text linkMetabolic dysfunction-associated steatotic liver disease (MASLD) is emerging as a
leading cause of chronic liver disease. In recent years, artificial intelligence (AI) has attracted
significant attention in healthcare, particularly in diagnostics, patient management, and
drug development, demonstrating immense potential for application and implementation.
In the field of MASLD, substantial research has explored the application of AI in various
areas, including patient counseling, improved patient stratification, enhanced diagnostic
accuracy, drug development, and prognosis prediction. However, the integration of AI in
hepatology is not without challenges. Key issues include data management and privacy,
algorithmic bias, and the risk of AI-generated inaccuracies, commonly referred to as
“hallucinations”. This review aims to provide a comprehensive overview of the applications
of AI in hepatology, with a focus on MASLD, highlighting both its transformative potential
and its inherent limitations
Preclinical Performance of a Novel Dental Implant Design Reducing Mechanical Stress in Cortical Bone
Full text linkThis animal study compared the healing performance of a novel implant design
characterized by a shift in thread geometry and core diameter with two different surfaces
with that of an apically tapered implant. Test Bioactive (n = 9), Test Porous (n = 7) and
Control (n = 8) implants were placed in the mandibles of minipigs. Following healing,
bone samples were harvested for determining bone-to-implant contact (BIC) and marginal
bone loss (MBL). Comparative statistics were based on Levene’s test, Shapiro–Wilk tests,
the Kruskal–Wallis test and Wilcoxon tests with Holm correction (α = 0.05). The mean
undersizing of the osteotomy was 0.15 mm for Control, while in the test groups 0.33 mm and
0.34 mm were calculated. Insertion torques ranged from 61.5 Ncm (Control) to 76.1 Ncm
(Test Bioactive). Maximum BIC was seen in Test Porous with 55.83%, while Test Bioactive
showed only 48.11%. MBL was 4.1 mm in Test Bioactive, while Test Porous and Control
exhibited 2.8 mm. No significant differences between the implant groups were observed
(p > 0.05). Despite greater undersizing, the novel implant type performed comparably to
the established Control implants. The rougher surface of the bioactive implants increased
the insertion torque and led to more MBL
Impact of Size and Substitution Isomerism in Polycyclic Aromatic-Substituted Trialkoxysilanes on the Formation of Softenable Polysilsesquioxanes
Full text linkPolyphenylsilsesquioxanes are known to form glassy materials that can reversibly soften when heated above their glass
transition temperature, with irreversible curing occurring upon a further temperature increase. In this study, the effects of the size
and isomerism of polycyclic aromatic groups on the synthesis and structure of polysilsesquioxanes are investigated, with a focus on
their thermoplastic and thermoset properties. Polysilsesquioxanes were synthesized by acid-catalyzed polycondensation using 1-
naphthyl, 2-naphthyl, and 9-phenanthrenyltrimethoxysilanes. Characterization techniques, including spectroscopy, thermal analysis,
mass determination, and powder X-ray diffraction, showed that steric hindrance by the aromatic groups significantly affects the
degree of condensation, the formation of OH groups, and the nature of intra- or intermolecular condensation. Bulky phenanthrenyl
groups hinder chain mobility and prevent detectable flow behavior, while 1- and 2-naphthyl groups enable the formation of
thermoplastic materials with reversible softening. Notably, 2-naphthylsilsesquioxane undergoes irreversible curing at 200 °C, whereas
1-naphthylsilsesquioxane resists this transition. The incorporation of both polycyclic substituents not only preserves the
characteristic thermoplastic behavior of melting gels but also introduces additional properties, such as fluorescence, a high thermal
stability up to 460 °C and a high refractive index of 1.61, enhancing the potential of these materials for optical applications
A Pedaling Torque Observation Approach for Sensorless Electric Bicycles
Full text linkThis study proposes an innovative unknown input observation approach based on Kalman
filtering to estimate the cycling torque and provide assistance in electrically powered bicycles. Specifically,
a constant and a sinusoidal pedaling torque model are compared, underlining the need for an enhanced
mathematical description to improve system performance. Using a nonlinear model of the bicycle
longitudinal dynamics, the cycling torque is reconstructed with an Extended Kalman Filter. Also, an online
low-computational effort road slope estimation method based on Kalman filtering, that accounts for
cornering effect errors, is proposed. The considered approaches, that utilize wheel speed, inertial, and motor
current measurements, are tested in an outdoor setting with variable slopes and curves. Differently from
the current state-of-the-art, the estimation performances are not only expressed in terms of pedaling torque
estimation error minimization. This work presents a novel pedaling power and delivered energy analysis to
evaluate the provided electrical assistance and the consequent pedaling effort decrease. The experimental
results show that a cycling endeavor reduction, similar to what can be achieved when electrical assistance is
provided employing a torque sensor, is possible, especially when relying on improved pedaling modeling
Synthese von Bottromycin-Derivaten und Totalsynthese von Crossiguanipyrazin I
No full textDer erste Teil dieser Arbeit befasst sich mit der Synthese neuer Bottromycin-Derivate. Dafür wurde eine flexible und konvergente Synthesestrategie entwickelt, die eine Modifizierung an nahezu jeder Stelle des Bottromycin-Gerüsts zulässt. Die dafür benötigten Peptid-Bausteine wurden mit Hilfe der Ugi Reaktion aufgebaut und waren damit in nur einem Schritt schnell verfügbar. Im Schlüsselschritt der Synthese wurden diese in einer Quecksilber-vermittelten Amidinierung miteinander geknüpft und abschließend makrolactamisiert. Außerdem gelang die enantioselektive Herstellung der in der Seitenkette befindlichen ungewöhnlichen Aminosäure (2S,3S)-3-Methylphenylalanin unter Verwendung der Matteson-Homologisierung. Insgesamt konnten sechs verschiedene Derivate hergestellt und biologisch evaluiert werden. Zwei der getesteten Derivate zeigten eine biologische Aktivität gegen verschiedene gram-positive Bakterien. Im zweiten Teil dieser Arbeit wird, zur Verifizierung der postulierten Struktur, die Totalsynthese des Naturstoffs Crossiguanipyrazin I behandelt. Bei der Synthese handelt es sich um die erste Totalsynthese dieser Naturstoffklasse. Die Crossiguanipyrazine wurden 2024 von Fu et al. aus dem Actinobacterium Crossiella cryophila DSM44230 isoliert und weisen eine potente Anti-tuberkulose Wirkung auf. Zentraler Bestandteil der Synthese war der Aufbau des vierfach substituierten Pyrazin-Rings sowie die simultane Einführung dreier Guanidin-Gruppen.In the first part of this PhD thesis the synthesis of new bottromycin derivatives is reported. A flexible and convergent synthetic strategy was developed, enabling modifications at nearly any position of the bottromycin scaffold. The required peptide building blocks were synthesized using the Ugi reaction, making them easily available in just one step. In the key step of the synthesis, these building blocks were coupled via a mercury-mediated amidination, followed by macrolactamization. Additionally, the enantioselective synthesis of the unusual amino acid (2S,3S)-3-methylphenylalanine was achieved using the Matteson homologation. A total of six different derivatives were synthesized and biologically evaluated. Two of these derivatives demonstrated biological activity against various gram-positive bacteria. The second part of this thesis describes the total synthesis of the natural product crossiguanipyrazine I to confirm the postulated structure. The synthesis represents the first total synthesis of this class of natural products. Crossiguanipyrazines were isolated from the actinobacterium Crossiella cryophila DSM44230 in 2024 by Fu et al. and show some potent anti-tuberculosis activity. The key steps of the synthesis involved the formation of the fourfold substituted pyrazine ring and the simultaneous introduction of three guanidine groups