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Genetic and environmental regulation of arbuscular mycorrhizal responsiveness in petunia: Implications for breeding and trait selection
No full textExploring shaped focused ion beams for lamella preparation
No full textFocused ion beams (FIB) are widely used instruments in transmission electron microscopy (TEM) sample preparation across scientific disciplines. Generally, site-specific ablation of material is achieved by scanning a highly focused probe across a selected area, leading to the removal of material. However, the geometries of TEM lamellae milled with the FIB are usually highly non-isometric, with their thickness generally being orders of magnitude smaller than their width and length. Here, we explore a changed probe shape for milling. Instead of using an ion beam with the standard, Gaussian-like probe, we characterize the use of the stigmator as quasi-cylindrical lens to create a highly astigmatic probe that we term 'ion knife'. Using the ion knife allows for material removal by spreading the current over a larger area and changes the dimension of the probe as observed in spot burn cross-sections. To allow for rapid alignment of parameters in beam shaping, we demonstrate a method to approximate the shapes of our probes by imaging. Finally, exploring shaped probes in cryogenic lamella preparation, we demonstrate the feasibility of cellular lamella milling and sectioning of cryo-lift-out volumes with the ion knife
Spectral Tuning of Hyperbolic Shear Polaritons in Monoclinic Gallium Oxide via Isotopic Substitution
No full textHyperbolic phonon polaritons - hybridized modes arising from the ultrastrong coupling of infrared light to strongly anisotropic lattice vibrations in uniaxial or biaxial polar crystals - enable to confine light to the nanoscale with low losses and high directionality. In even lower symmetry materials, such as monoclinic β-Ga2O3 (bGO), hyperbolic shear polaritons (HShPs) further enhance the directionality. Yet, HShPs are intrinsically supported only within narrow frequency ranges defined by the phonon frequencies of the host material. Here, we report spectral tuning of HShPs in bGO by isotopic substitution. Employing near-field optical microscopy to image HShPs in 18O bGO films homoepitaxially grown on a 16O bGO substrate, we demonstrate a spectral redshift of 40 cm-1 for the 18O bGO, compared to 16O bGO. The technique allows for direct observation and a model-free estimation of the spectral shift driven by isotopic substitution without the need for knowledge of the dielectric tensor. Complementary far-field measurements and ab initio calculations - in good agreement with the near-field data - confirm the effectiveness of this estimation. This multifaceted study demonstrates a significant isotopic substitution induced spectral tuning of HShPs into a previously inaccessible frequency range, creating new avenues for technological applications of such highly directional polaritons
Field Strength-Dependent White Matter R1 and R2 Anisotropy of Phase-Cycled Balanced Steady-State Free Precession Relaxometry
No full textPurpose: To investigate how the relaxation rates (R1, R2) and asymmetry indices (AI), derived from phase-cycled balanced steady-state free precession (pc-bSSFP) data, depend on the orientation of white matter (WM) fiber tracts at different field strengths.Methods: Phase-cycled bSSFP data acquired at 3 and 9.4T in the healthy human brain were processed using motion-insensitive rapid configuration relaxometry (MIRACLE) and a frequency response analysis to derive R1, R2, and AI values, respectively. Fractional anisotropy (FA) and fiber-to-field angle (θ) were estimated based on 3T diffusion tensor imaging. The orientation dependence of R1, R2, and AI in WM was characterized using literature model fits as well as Monte Carlo random walk simulations to explore the influence of field strength and susceptibility effects.Results: R2 and AI exhibited a pronounced orientation dependence while the influence of anisotropy on R1 was weaker, but noticeable. The observed anisotropy increased systematically from 3 to 9.4T. Literature models assuming either a susceptibility or a generalized magic angle effect described the R2 and AI anisotropy to a high degree (R2 ≥ 0.99). The calculated partial contributions of susceptibility to R2 anisotropy increased from 24.0%-39.0% at 3T to 77.0%-87.1% at 9.4T. The Monte Carlo simulations were able to reproduce the characteristics of R2 anisotropy, but not its strength.Conclusion: Microstructure-driven relaxation anisotropy considerably affects pc-bSSFP relaxometry, in particular R2. The findings indicate that R2 anisotropy is driven by susceptibility at ultra-high fields whereas additional mechanisms likely contribute at lower field strengths
Predictive models for active suicidal ideation in cognitive decline: identifying risk factors
No full textSuicide rates among older adults with cognitive decline represent a critical public health concern. Despite the association between cognitive decline and suicidality, predictive models for active suicidal ideation (ASI) in this population remain underexplored
Von Werten zu Vetos: gemeinsame Wissenschaftsfinanzierung in Zeiten autoritärer Versuchungen
No full textPotential of Vagus Nerve Stimulation to Modulate Fibromyalgia’s Network Physiology: A Systematic Review
No full textBackground: Chronic pain conditions such as fibromyalgia syndrome (FMS) reflect maladaptive network physiology across perceptual–autonomic–immune axes, yet most treatments remain symptomatic and incompletely effective. Methods: We conducted a comprehensive systematic review to evaluate vagus nerve stimulation (VNS) and FMS within a network physiology framework. PubMed, Embase, and Cochrane CENTRAL were searched on October 24, 2025. Risk of bias was assessed using the ROB-2 tool. An iterative thematic synthesis was performed to develop an integrative conceptual framework and to identify knowledge gaps and future research directions. Results: We first summarize physiological evidence showing autonomic imbalance (e.g., decreased heart rate variability), neuroinflammatory activation, and aberrant cortical network connectivity in FMS, supporting a network-dysregulation model. We then included 6 studies (4 clinical studies and 2 protocols) on VNS effects, highlighting improvements in pain, fatigue, sleep disturbance and autonomic regulation, along with emerging mechanistic insights. Key methodological heterogeneity—such as stimulation parameters, outcome metrics, type of control arm, sham definition, and small samples—limits current interpretability. Finally, we outline a research agenda centered on network-based biomarkers, immunophenotyping, adaptive trial designs and stratification of responders, with the aim of validating taVNS as a scalable neuromodulatory intervention for FMS. Conclusions: By reframing FMS from a symptom-centric pharmacologic model to a network-centric neuromodulation approach, taVNS is a promising tool for mechanism-based therapeutics in central sensitization syndromes and chronic pain
Patterns of understorey bird diversity across Amazonian forests: survey effort and range maps predict local species richness
No full textConservative Black Hole Scattering at Fifth Post-Minkowskian and Second Self-Force Order
No full textUsing the worldline quantum field theory formalism, we compute the conservative scattering angle and impulse for classical black hole scattering at fifth post-Minkowskian (5PM) order by providing the second self-force (2SF) contributions. This four-loop calculation involves non-planar Feynman integrals and requires advanced integration-by-parts reduction, novel differential-equation strategies, and efficient boundary-integral algorithms to solve a system of hundreds of master integrals in four integral families on high-performance computing systems. The resulting function space includes multiple polylogarithms as well as iterated integrals with a K3 period, which generate a spurious velocity divergence at . This divergence is present in the potential region and must be cancelled by conservative memory contributions from radiative regions. We find that the standard use of Feynman propagators to access the conservative sector fails to ensure this cancellation. We propose a conservative propagator prescription which realises both cancellations leading to a physically sensible answer. All available low-velocity checks of our result against the post-Newtonian literature are satisfied
Site defects and structural alignment enhance interfacial charge mobility in heterostructured carbon nitride catalysts
No full textEngineering interfaces between organic semiconductors is an effective way to tailor organic electronic device performance, as charge transport and light interaction efficiency are strongly influenced by electronic coupling at molecular interfaces. Scanning transmission electron microscopy is routinely used to analyze interfaces at the atomic scale; however, its use for organic materials is limited due to the electron beam sensitivity of organic molecules, buried interfaces, and the semicrystalline nature of organics. In this work, we developed a workflow to correlate charge behavior at organic interfaces with their chemistry and structure, even when interface components are chemically and structurally similar and mixed at the nanoscale. We used this workflow to reveal the nanoscale mechanism behind enhanced charge transfer at the heterojunction between two-dimensional carbon nitride catalysts (poly-heptazine imide (PHI) and poly-triazine imide (PTI)) during the oxygen reduction reaction. We found that PHI crystallites grow on PTI layers formed at the gas–liquid interface in the salt melt, following the [001]PTI/[001]K-PHI orientation. This crystallographic alignment promotes the charge transfer from PTI to PHI and creates an electron-rich interface. Electron energy loss spectroscopy showed quaternary N atoms in the heterojunction, which aid O2 adsorption and 2e– reduction to H2O2, as well as a higher proportion of terminal and bridging N atoms, promoting charge separation during the reaction