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Anomalous impurity-induced charge modulations in black phosphorus
No full textWe observe anomalous charge modulations induced by ionized indium impurities on the surface of the semiconductor black phosphorus by scanning tunneling microscopy (STM). When the impurities are switched into a negatively charged state by the STM tip, periodic charge modulations emerge around the impurity center, but strictly confined by the nanoscale impurity potential. These modulations form a distorted triangular pattern, whose periodicity remains unchanged in a wide range of positive bias. Furthermore, these local charge orders exhibit an anisotropy opposite to that expected based on the anisotropy of the Fermi surface, challenging a simple band-structure interpretation. Our experiment demonstrates the possibility of creating and manipulating macroscopic charge orders through impurity engineering
Surface Diffusion in SnTe‐PbTe Monolayer Lateral Heterostructures
No full textThe construction of complex functional heterostructures from low-dimensional materials requires creating atomically sharp vertical and lateral interfaces. While vertical heterostructures of 2D materials can be readily formed through stacking, the growth of lateral heterostructures faces a larger challenge and is relatively less understood. Particularly, suppressing atomic or molecular interdiffusion at lateral heterointerfaces is critical for obtaining atomically sharp 2D lateral heterostructures. Here, using in situ scanning tunneling microscopy, we observe a surface diffusion mechanism that becomes dominant at the molecular beam epitaxially grown 1D interfaces of lateral heterostructures between SnTe and PbTe monolayers, which are 2D ferroelectric and paraelectric semiconductors, respectively. This mechanism, which does not exist in the vertical heterostructures with 2D interfaces, is responsible for the asymmetric interdiffusion at the two different types of interfaces—those with PbTe grown outside of SnTe, and those with SnTe grown outside of PbTe. By optimizing the relative parameters including substrate temperature, molecular fluxes, and the thickness of the graphene substrate, we have realized nearly atomically sharp lateral heterointerfaces with suppressed interdiffusion. This study paves the way to creating clean and sharp SnTe-PbTe interfaces for valleytronic and quantum information devices that require ultra-narrow lateral heterostructures
Nanocoated bacteria for sustainable fertilization
No full textFoliar application of nanocoated inoculates encapsulating Klebsiella variicola W12 enhanced nitrogen fixation under nitrogen-depleted conditions, representing a sustainable strategy to increase crop productivity
Mental health in recreational and professional dancers: A genetically informed study in Sweden
No full textWhile recreational dancing has been associated with positive health outcomes, professional dancers tend to experience more mental health problems. Here, we studied the relationship between self-reported engagement and achievement in dance (from no involvement to high-level professional dancing) and mental health problems including work-related depressive symptoms, emotional exhaustion, and registry-based psychiatric diagnoses (major depression, anxiety, and stress-related diseases). Utilizing a genetically informative population sample of 6610 Swedish twins, we estimated heritability for dance achievement and associations between dance achievement and mental health outcomes, and tested whether observed associations are consistent with causal effects by accounting for familial confounding using a co-twin control design. Individual differences in dance achievement were more heritable in females (60%) than in males (29%). Professional dancers had a higher risk for mental health problems than recreational dancers and non-dancers, but these associations became non-significant after adjusting for familial confounding, suggesting that shared familial factors – rather than professional dancing itself – largely explained the elevated risk. In contrast, we found no evidence for a protective effect of recreational dancing on mental health. These findings highlight the importance of considering underlying familial and genetic factors when addressing mental health risks in professional dancers, and they point toward future interventions focusing on early identification and support for vulnerable individuals rather than targeting dance practice itself as a causal factor
From Thin Films to Nanodots: Bottom-Up Integration of Fe<sub>3</sub>O<sub>4</sub> on Nb:STO for Functional Oxide Nanostructures
No full textParticle background characterization and prediction for the NUCLEUS reactor CEνNS experiment
No full textNUCLEUS is a cryogenic detection experiment which aims to measure Coherent Elastic Neutrino–Nucleus Scattering (CEνNS) and to search for new physics at the Chooz nuclear power plant in France. This article reports on the prediction of particle-induced backgrounds, especially focusing on the sub-keV energy range, which is a poorly known region where most of the CEνNS signal from reactor antineutrinos is expected. Together with measurements of the environmental background radiations at the experimental site, extensive Monte Carlo simulations based on the Geant4 package were run both to optimize the experimental setup for background reduction and to estimate the residual rates arising from different contributions such as cosmic ray-induced radiations, environmental gammas and material radioactivity. The NUCLEUS experimental setup is predicted to achieve a total rejection power of more than two orders of magnitude, leaving a residual background component which is strongly dominated by cosmic ray-induced neutrons. In the CEνNS signal region of interest between 10 and 100 eV, a total particle background rate of ∼ 250 d−1 kg−1 keV−1 is expected in the CaWO4 target detectors. This corresponds to a signal- to-background ratio 1, and therefore meets the required specifications in terms of particle background rejection for the detection of reactor antineutrinos through CEνNS
Predatory aggression evolved through adaptations to noradrenergic circuits
No full textBehaviors are adaptive traits evolving through natural selection. Crucially, the genetic, molecular, and neural modifications that shape behavioral innovations are poorly understood. Here, we identify specialized adaptations linked to the evolution of aggression in the predatory nematode Pristionchus pacificus. Using machine learning, we identified robust behavioral states associated with aggressive episodes. These depend on modifications to the invertebrate noradrenergic pathway, with octopamine promoting predatory bouts, and tyramine antagonistically suppressing predation. Strikingly, aggression coincides with rewiring of key circuits across nematode evolution. We find additional octopaminergic neurons with morphological adaptations, including neurites extending to teeth-like structures, and expanded receptor expression throughout head sensory neurons gating prey detection. Thus, evolutionary adaptations in noradrenergic circuits facilitated the emergence of aggressive behavioral states associated with complex predatory traits
Post-drought vegetation shifts lead to divergent carbon, water and energy responses in a Savanna ecosystem of southwest China
No full textA material approach to endangered species conservation : characterization and 3D imaging of ballistic damage in the casques of helmeted hornbill (Rhinoplax vigil)
No full textThe helmeted hornbill (Rhinoplax vigil), a critically endangered bird prized for the distinctive helmet-like “casque” capping its beak, faces threats from poaching and habitat loss. This study applies biomaterials/imaging techniques to wildlife forensics, using micro-computed tomography to forensically analyse bullet-induced damage in a unique collection of helmeted hornbill skull specimens, confiscated by the Agriculture, Fisheries and Conservation Department (AFCD) of Hong Kong. The findings reveal diverse healing responses, bullet characteristics and indications of the poaching strategies used. For example, specimen scans—showing various bullets embedded in skull tissue—suggest that poachers may use the conspicuous casque as a target when shooting upward from the ground. Additionally, our observations of casque anatomy exhibit two different types of tissue repair, arguing that several of the individuals lived long after being shot. The study highlights the value of confiscated specimens for understanding life history factors and poaching impacts in rare species, vital for developing tailored conservation strategies and advancing knowledge of the biology of elusive wildlife
Supramolecular carbohydrate assemblies with tunable glycan surfaces
No full textThe self-assembly of molecular building blocks into ordered supramolecular structures enables the creation of nanomaterials that can display ligands on their surfaces with molecular precision. However, many of these supramolecular scaffolds face challenges in incorporating bulky or hydrophilic ligands, such as carbohydrates. This issue often requires the co-assembly of ligand-containing blocks with non-functionalized ones, diluting ligand presentation and compromising their precise spatial arrangement. Herein, we present carbohydrate oligomers that assemble into supramolecular nanomaterials featuring a molecularly controlled, dense presentation of carbohydrate ligands on their surfaces. This modular system accommodates a variety of carbohydrate ligands while maintaining consistent bulk material properties. Using this approach, we have engineered a series of supramolecular hydrogels, whose nanostructure displays specific carbohydrate residues with high density that act as biological cues to influence the morphology of Candida albicans