Browse Articles

Wavelike thermal phonons revealed by localization in graphene phononic crystals

The high Debye temperature and ultralong phonon mean free paths (MFPs) of graphene phononic crystals (GPnCs) enable wavelike phonon transport to manifest over extended length scales, making them an ideal platform for studying phonon localization. We employ machine-learning molecular dynamics to investigate thermal transport in periodic and aperiodic GPnCs. By combining homogeneous non-equilibrium molecular dynamics and non-equilibrium molecular dynamics, we directly extract the spectrally decomposed phonon MFP applicable to aperiodic structures. Spectral analysis establishes characteristic frequency (ωc≈10 THz) and length (Lc≈100 nm) scales for localization effects, and the nonlinear deviation in the 1/κ–1/L relationship (κ: thermal conductivity) indicates the presence of localized phonons. Lattice dynamics reveals that the increased fraction of low-participation-ratio modes and the absence of high-group-velocity modes in aperiodic graphene phononic crystals (ap-GPnC) uncover the microscopic origin of disorder-induced phonon localization. Elastic wave simulations further provide direct wave-field evidence of pronounced spatial localization of low-frequency phonons in ap-GPnC with increasing propagation distance.

An adaptive A-Star algorithm to handle blood transportation using UAVs

Serum levels of immunoglobulin G and M antibodies against SARS-CoV-2 in asymptomatic individuals prior to COVID-19 vaccination in the Democratic Republic of Congo

Despite the production of protective cross-reactive antibodies during COVID-19, data on immunoglobulin G (IgG) and immunoglobulin M (IgM) levels prior to vaccination remain limited in the Democratic Republic of Congo (DRC). This study aimed to assess serum IgG and IgM antibodies against SARS-CoV-2 in asymptomatic individuals COVID-19 vaccination in the DRC. A total of 1,500 individuals who presented for COVID-19 vaccination at the University Clinics of Kinshasa between April 19 and December 31, 2021, were included. The mean age was 47.5 ± 16.0 years, with a predominance of males (69.4%, sex ratio 2:1). Prior to vaccination, 38.8% of participants had elevated IgG levels, while 32.9% had elevated IgM levels. After multivariable adjustment, female sex (adjusted odds ratio [aOR] 1.54; 95% confidence interval [CI] 1.14–2.46), non-healthcare professional status (aOR 2.24; 95% CI 1.42–3.58), and the absence of comorbidities (aOR 2.33; 95% CI 1.38–3.71) remained independently associated with IgM seropositivity. Overall, IgG and IgM seroprevalence were high prior to vaccination. IgM positivity was associated with specific sociodemographic, biochemical, and hematological profiles. These findings highlight the importance of routine serological surveillance before vaccination to better understand infection dynamics and to inform public health interventions.

Enhancing Memory of Chirality in Phosphorus‐Centered Radicals by Inductive Deceleration of Pyramidal Inversion

ABSTRACT The realization of stereospecific radical reactions—particularly those involving heteroatom‐centered radicals—remains a formidable challenge due to the rapid configurational inversion (racemization) of transient radical intermediates. This study presents a general strategy to enhance the memory of chirality (MOC) in radicals by exploiting the inductive effect of substituents. Through DFT calculations, we demonstrate that the pyramidal inversion barrier of phosphorus‐centered radicals can be dramatically increased by substitution with highly electronegative atoms. This deceleration of inversion enables stereoretentive transformations of enantiopure H‐phosphinates under mild, radical conditions. A series of stereospecific phosphoryl radical reactions, including alkene hydrophosphonylation, intramolecular arylphosphonylation, phosphorylation–cyclization of isocyanates, and aryl migration reactions, were successfully developed, providing access to diverse P(V)‐stereogenic compounds with high efficiency (up to 99% yield) and excellent stereospecificity (up to >99% es ). The utility of this approach is highlighted by the late‐stage functionalization of densely functionalized pharmaceuticals, bioactive molecules, and a liquid crystal. This work establishes a foundational principle for achieving stereochemical control in radical reactions via rational tuning of the radical intermediate's configurational stability.

Polar topological transitions in PbTiO3 thin films affected by oxygen vacancy content and film thickness

Topological polar textures in ferroelectric films show fundamental physics, intriguing topology, and technological prospects. Understanding the conditions for the emergence of polar topological textures is crucial for future applications. Here, a series of PbTiO3 thin films were grown by pulsed laser deposition via varying the oxygen partial pressure (i.e., oxygen vacancy content) and pulse number (i.e., film thickness). It was found that ∼10-nm-thick films grown at lower oxygen partial pressures exhibit a higher oxygen vacancy content. By decreasing the oxygen partial pressure from 26 to 10 Pa, the as-grown films transition from a downward c-monodomain state to an upward c-monodomain state. Interestingly, at the relatively low oxygen partial pressure of 10 Pa, by further increasing the pulse number from 1500 to 6500, the as-grown films transition from the upward c-monodomain state to a polar skyrmion state, a labyrinth state, and finally a c-domain-dominated state with sparse a-domains. Phase-field simulations indicate that the intricate evolution of polar states mainly arises from the competition between elastic and electrostatic energies modified by the growth conditions. This work should extend our current understanding of the formation mechanism of topological polar states in ferroelectric thin films.

High precision measurements of the hyperfine structure of Vanadium ions in the ultraviolet range

Abstract High resolution collinear laser spectroscopy has been performed on singly charged ions of $$^{50,51}$$ V at the IGISOL facility of the Accelerator Laboratory, University of Jyväskylä, Finland. Eleven ionic transitions were investigated in the ultraviolet wavelength range, improving the precision of the known hyperfine parameters and providing newly measured values. We report also the isotope shifts between the two natural isotopes for five of the studied transitions. These results provide benchmark data for the electronic structure of vanadium and open the way for future studies of nuclear-structure phenomena along the vanadium isotopic chain using laser spectroscopy techniques.

Non-linear impacts of local fiscal expenditure on farmers’ income: A SHAP-informed machine-learning analysis

Understanding how local fiscal spending shapes rural income is central to China’s rural revitalisation strategy. Using panel data from 17 prefecture-level cities in Henan Province for 2010–2023, this study investigates the non-linear and heterogeneous effects of fiscal expenditure on farmers’ per-capita income. A hybrid econometric–machine learning framework is developed, combining city–year fixed effects with a residual XGBoost learner and SHapley Additive exPlanations (SHAP) to capture both the linear baseline relationships and complex non-linear interactions among fiscal items while retaining interpretability. Model evaluation based on repeated nested cross-validation and 500 permutation tests demonstrates high predictive reliability (out-of-sample R 2  = 0.924, p = 0.002). SHAP-based analysis reveals that healthcare and education spending are the dominant determinants of rural income, jointly accounting for over 40% of model influence. Partial-dependence plots uncover clear threshold effects: education and health expenditures exhibit inverted-U shapes with turning points at approximately ¥1,800 and ¥1,050 per rural resident (2015 prices), respectively. Infrastructure investment shows consistently positive but diminishing returns, while social-security transfers produce concave yet non-negative effects. Heterogeneity analysis further indicates that low-capacity cities derive greater benefits from technology and transport spending, whereas high-capacity cities gain more from health and urbanisation budgets. Robustness tests across alternative learners (Random Forest, LightGBM) and variable definitions confirm the stability of these non-linear thresholds. The results highlight the importance of optimising fiscal composition rather than merely increasing total spending, suggesting that city-specific expenditure ceilings—particularly for education and health—could raise rural incomes by 2–3% while enhancing fiscal efficiency.

Blooming flexoelectricity in 2D materials revealed via second-harmonic generation

Flexoelectricity—the coupling between strain gradients and polarization—offers a powerful route to engineer electromechanical responses, yet its straightforward detection at the nanoscale remains challenging. Here, we establish second-harmonic generation (SHG) as a noninvasive optical probe for the nanoscale strain gradient in two-dimensional (2D) materials. Using MoS2 as a model D3h system, we show that the bending-induced strain gradient εxx,z breaks mirror symmetry and transforms the canonical six-lobed SHG polar pattern into a “blooming core.” SHG imaging resolves strain gradients on the order of 0.1 μm−1, with intensity scaling positively with the gradient—opposite to the monotonic decay under uniform strain. This signature is universal across MoSe2, WS2, WSe2, and hexagonal boron nitride (h-BN), and recurs in diverse geometries, including wrinkles, bubbles, and microholes. Quantitative analysis further reveals a linear scaling between the square root of SHG intensity and the strain gradient. Our results establish a versatile optical platform for nanoscale flexoelectric studies in 2D materials.

Transfer learning enhanced deep neural network surrogate model for rapid multiphysics simulation of alkaline water electrolyzers

Policy Modeling Consistency index-based study on policy synergy for sustainable artificial intelligence in China’s digital cultural industries

This paper applies the Policy Modeling Consistency (PMC) index model to quantitatively evaluate 32 Chinese policies (2016–2025) promoting artificial intelligence (AI) in digital cultural industries (DCIs). Focusing on policy synergy for sustainable AI, the analysis assesses ten primary variables—including policy objectives, instruments, sustainability integration, and application levels—across national and local initiatives. Results reveal an overall ‘Excellent’ average PMC score, indicating robust policy design in economic or technological domains. However, some low-grade policies prioritize short-term regulation over sustainable governance. The study recommends embedding ‘human-centricity’ and ‘ethical risk assessment’ in sustainability indicators, alongside cultural diversity safeguards (e.g., algorithmic support for intangible heritage). These optimizations can reframe AI as a socio-cultural enabler—not merely a technical tool—advancing equitable, innovative, and ecologically resilient DCIs aligned with Sustainable Development Goals (SDGs).

Decay dynamics of topological valley-Hall edge states in multicomponent diffusive systems

Triggered by the discovery of topological insulators, applications that utilize topological properties are extended to diffusion systems. In this study, we investigate the decay dynamics of topological valley-Hall edge states in systems containing multiple interactive diffusive quantities. We find that the interaction between the diffusive quantities lifts the degeneracy of the edge modes, splitting them into fast-decaying and slow-decaying modes. In addition, our analysis reveals that the eigenfunctions of the edge modes have different polarities, resulting in attraction and repulsion between the two diffusive quantities, depending on the excited modes. These findings suggest the possibility of tailoring decay rates in multicomponent diffusive systems.

The role of NLRP3 neuroinflammation in cognitive frailty diversity during aging and after LPS administration in mice

Is it inside my head? Characterization of sound externalization in schizophrenia

Schizophrenia has been linked to reality monitoring confusions, particularly misattributions of internal productions to external sources. We hypothesized that these misattributions may be related to deficits in processing acoustic cues that distinguish the subjective experience of a sound source inside or outside the head, i.e., sound externalization. This study aimed to investigate sound externalization in patients with schizophrenia, particularly for emotional sounds, as emotion influences auditory perception. In an externalization task, twenty-three patients with schizophrenia and twenty-five healthy controls were exposed to neutral and emotional sounds processed to be perceived as: internalized (diotic) or externalized (filtered with either an anechoic head-related transfer function -HRTF- or a binaural room impulse response -BRIR). Participants had to indicate whether the sound source was perceived inside or outside their head. Exploratory analyses also examined the relationships between externalization, reality monitoring, and symptom severity. Compared to controls, patients with schizophrenia rated the filtered sounds (HRTF, BRIR) as less externalized (corrected p < .001) and the diotic sounds as more externalized (corrected p < 0.001). Sounds with negative emotional (anger, fear) were more externalized (corrected p < .001) in both groups, but patients showed reduced externalization when compared to control for several emotions (anger, happiness, fear, sadness) (corrected p < .001). No significant correlation was found between externalization and reality monitoring. In patients, greater symptom severity was associated with reduced externalization of sounds simulated as originating outside the head. These findings suggest an abnormal perception of sound sources in patients with schizophrenia, who confuse sounds inside and outside the head to a greater extent with an influence of emotional contents. Further research is needed to elucidate the relationship between sound externalization and symptoms such as hallucinations.

Photoreflectance at operating bias links interface traps to photovoltaic performance in ZnSnP2 solar cells

We apply photoreflectance (PR) and electrically biased PR (EBPR) to quantify the electric field and interface trap density at the CdS/ZnSnP2 junction in ITO/CdS/ZnSnP2/Cu3P/Cu solar cells and relate them to device performance. PR spectra exhibit Franz–Keldysh oscillations above the ZnSnP2 band edge, yielding the surface electric field and surface potential. EBPR provides the surface-potential dependence on DC bias in the forward-bias range relevant to solar-cell operation. Applying the Terman formalism to this dependence yields the energy-resolved interface trap density (Dit), which is donor-like. A cell with a dominant Dit component at ∼0.3 eV above the ZnSnP2 valence band maximum shows a lower short-circuit current density. In addition, this component lies near the surface potential corresponding to the diode knee, where its occupancy changes during operation, suggesting that recombination via this state contributes to the higher dark ideality factor and reduced open-circuit voltage. PR/EBPR thus offers a practical layer-selective approach to link operational electric fields and interface traps to photovoltaic performance.

Unravelling complex interactions during Toxoplasma, Plasmodium, and Leishmania co-infections in French Guiana

Abstract Toxoplasma gondii , Plasmodium spp., and Leishmania spp. collectively infect billions and cause millions of deaths worldwide. In French Guiana, the geographical coexistence of malaria, acute toxoplasmosis, and cutaneous leishmaniasis may result in sequential or simultaneous infections. This study assesses the seroprevalence of protozoan multi-infections and their impact on host responses compared to individual infections. We analyzed plasma samples and clinical data from patients with these diseases and healthy controls ( n  = 253) collected at Cayenne Hospital Centre between 2012 and 2022. Seroprevalence for T. gondii , Plasmodium spp. and Leishmania spp. was determined using chemiluminescence and ELISA, and cytokine and chemokine levels were measured via a multiplex assay. Multivariate analysis was utilized to identify distinct biological markers and disease signatures of single and co-infections. About 60% of patients were seropositive for at least two pathogens, with 2.4% having concomitant infections. Significant differences were noted in cytokine profiles, particularly levels of IL-10, IL-17, IL-33, and IFN-α, between single and co-infected patients. These results underline the complex dynamics and high prevalence of co-infections, providing crucial insights for developing effective public health strategies and biomarkers, especially in endemic regions.

Correction: Workplace stress, support and stress management strategies for healthier lifestyles among healthcare workers in Ethiopia

3 <i>d</i> cation substitution for tuning the magnetic properties of ultrathin La-based high-entropy perovskite oxides

A single-crystal high-entropy oxide provides an ideal structure to explore how multication substitution affects magnetic properties. In this study, several ultrathin La-based low-, medium-, and high-entropy perovskite oxides (ABO3) are synthesized through entropy engineering. The B-site cations in the single-crystal ABO3 structure are occupied by transition metals (Mn, Cr, Cu, Co, Ni, and Fe). The effects of multiple B-site substituents on the magnetic properties of the ultrathin nanosheets are extensively characterized via x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and magnetic measurements. Some samples of La(MnFeCoNi)O3, La(CuMnFeCoNi)O3, and La(CrMnFeCoNi)O3 exhibit a notable magnetic phase transition from ferromagnetic to paramagnetic states, along with a remarkable enhancement in coercivity. Moreover, these ultrathin samples display low magnetic ordering temperatures due to the structure–magnetic property correlations rather than epitaxial strain, demonstrating flexible and maneuverable magnetic responses.

Three-dimensional passive acoustic mapping of high intensity focused ultrasound fields using sparse synthetic apertures from rotated one-dimensional linear arrays

Assessing the impact of timely diagnosis on psychological outcomes and quality of life for cancer patients: A scoping review

Objective We explored the literature on timely cancer diagnosis and its significance on psychological outcomes or quality of life in cancer patients. Design A scoping review to map existing literature in this area, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Results Six studies were identified. Four studies used cross-sectional surveys, and one each used qualitative and mixed-method designs. Quantitative evidence suggests that timely diagnosis was associated with better psychological outcomes and quality of life. Qualitative and mixed-method evidence found an incidental relationship, but it was not a focus of the studies. There were varied definitions of timely diagnosis, and a diverse range of measures were used to identify outcomes. No study satisfied all quality appraisal criteria, with key dates in the diagnostic journey being the least reported (0/6 studies). Conclusions Preliminary evidence indicates that timely diagnosis may be associated with variations in psychological outcomes and quality of life in patients with cancer; however, methodological heterogeneity restricts the generalisability of the findings. More high-quality longitudinal quantitative and qualitative research is needed to explore the direction of the association and lived experience during the adjustment process.

Quantitative insight into illumination-induced barrier lowering mediated by self-trapped-holes in Ga2O3 Schottky photodiodes

Anomalously high photoresponsivity exceeding the theoretical photovoltaic limit has been widely reported in Ga2O3 Schottky barrier photodiodes (SBPDs) but seldom observed in heterojunction photodiodes (HJPDs). Here, we quantitatively identify the illumination-induced Schottky barrier lowering (SBL) effect mediated by self-trapped holes (STHs) as the physical origin of this discrepancy. Bias-dependent photoresponse spectra, photocurrent transients, and Franz–Keldysh effect-based rigorous modeling reveal that an apparent photoresponsivity of 19.8 A/W and a corresponding external quantum efficiency (EQE) of 95.8 in β-Ga2O3 SBPD are results of a 0.22 eV reduction of the Schottky barrier under solar-blind illumination. The STH-mediated SBL facilitates electron injection under reverse bias, yielding EQE values far beyond the unity photovoltaic limit. In comparison, NiO/β-Ga2O3 HJPDs with type-II band alignment enable efficient extraction of photogenerated carriers and exhibit intrinsic photoresponse behavior. The model quantitatively elucidates the mechanism of STH-mediated photoresponse gain, offering physical insights for engineering ultrawide-bandgap photodetectors.