Two-dimensional hexagonal boron nitride (hBN) is attractive for several emerging applications. Ion bombardment can be used to modify the hBN properties. However, the understanding of radiation damage buildup in hBN remains limited. Here, we investigate the effects of the dose rate and ion mass on radiation damage buildup by studying 40 nm-thick hBN films bombarded at room temperature with 500 keV 4He, 15N, 40Ar, and 129Xe ions and comparing with results for ion bombardment of polycrystalline hBN ceramics. Raman spectroscopy is used to quantify damage buildup, and transmission electron microscopy is used for microstructural analysis. Experiments are complemented by molecular dynamics simulations of the formation and evolution of point defects. Lighter ions are found to be more efficient at disordering hBN than heavier ions. This observation points to a critical role of intracascade defect processes. In contrast, a negligible dose rate effect observed suggests limited intercascade defect dynamic annealing processes for these irradiation conditions. These findings provide a fundamental basis for hBN defect engineering.
The modification of graphene oxide by energetic ion beams offers a promising alternative to conventional reduction techniques, providing spatially controlled tuning of the structural and electrochemical properties. In this study, we investigate the effect of focused Cu ion beam irradiation on free-standing graphene oxide foils using a comprehensive suite of characterization methods, including scanning electron microscopy, energy-dispersive spectroscopy, Raman spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and scanning electrochemical microscopy. Cu ion bombardment was found to induce partial reduction of graphene oxide, evidenced by a decrease in oxygen content, an increased C/O ratio, and enhancement of graphitic carbon features. Scanning electrochemical microscopy measurements using the [Ru(NH3)6]3+ redox probe revealed significantly enhanced electrochemical activity in and around the irradiated regions. This enhancement is likely influenced by local thinning of the graphene oxide layer and the increased exposure of reactive edge regions generated during irradiation rather than adsorption effects being the dominant factor. Elemental mapping confirmed a depletion of the Ru signal within bombarded stripes, supporting the structural origin of activity enhancement. These findings establish Cu-ion irradiation as a reagent-free, maskless approach for nanoscale patterning of electrochemically active regions in graphene oxide, with potential applications in sensing, catalysis, and electronic devices.
Film optimization using high power impulse magnetron sputtering (HiPIMS) currently faces challenges in process control, primarily due to its reliance on empirical trial-and-error adjustment of the macroscopic parameters as well as the insufficient understanding of the underlying mechanisms. To address these issues, this study adopts concentration ratios of monovalent ions over divalent ions of the same metallic element (i.e., Me+/Me2+) in plasma as a function of key controlled discharge parameters. A mass spectrometer was employed for the in situ diagnostics of ionic species in HiPIMS discharges of Cr, Ti, and Al targets. The influence of discharge parameters on Me+/Me2+ ratios was systematically investigated. Combined with film characterization, the correlations of discharge parameters, ion concentrations, microstructure evolution, and mechanical properties were established. Results demonstrated that Me+/Me2+ ratios could be tuned significantly by varying discharge parameters. Decreasing the Me+/Me2+ ratio suppressed growth of columnar grains and promoted film densification due to enhanced high-energy bombardment. This study reveals the dominant role of the charge state distribution of metallic ions in HiPIMS on the microstructure and properties of nitride films, thereby providing a novel approach to deposition-process optimization, which can also be used as guidance for studies on ternary as well as high-entropy nitride films.
Incorporation of carbon-11 radiotracers for positron emission tomography (PET) imaging requires close coordination between cyclotron operation, radiochemistry production, quality control, and clinical administration. A persistent challenge exists is the minimization of the carbon-12 isotopologue mass of the radiotracer, which reduces molar activity and can compromise PET image quality. This challenge can be particularly acute at facilities where cyclotron operation and carbon-11 radiochemistry are realized by separate organizations with distinct operational priorities. Here, we describe how the Radiochemistry Group at New York University Grossman School of Medicine and Siemens Healthineers have developed an integrated operational framework for consistent, high-quality carbon-11 production within an academic-industry partnership. Cyclotron target maintenance and conditioning protocols, remote chemistry module maintenance schedules, a validated radio-HPLC method (UV LOD = 0.9 µg/mL, UV LOQ = 3.0 µg/mL) for trending methyl iodide isotopologue mass, and structured inter-team communication protocols are presented in this manuscript. Quality analysis demonstrates molar activities consistently exceeding the recommended minimum of 40 GBq/µmol for reversibly binding radiotracers used in human PET studies. This work is intended as a practical resource for radiochemists, cyclotron engineers, and facility managers working to establish or improve institutional carbon-11 programs.
Extensive evidence suggests that war-related trauma negatively affects health, yet its long-term and transgenerational effects on psychological and physical adjustment remain poorly understood. This study examines whether individuals who experienced greater war exposure in early childhood-specifically variation in bombardment intensity across German municipalities during the Second World War-show lower, similar, or better psychological (life satisfaction, affective well-being, and mental health) and physical adjustment (self-rated and physical health) in late adulthood compared to less exposed peers. The study also analyzes intergenerational effects by investigating whether the children of parents who were more versus less exposed to bombardments differed in psychological and physical adjustment in midlife. War exposure was measured using exogenous variation in regional housing destruction across 1,739 German municipalities (0%-97% destroyed) during the Second World War. Combining these historical data with individual data from the German Socio-Economic Panel, we analyzed three samples: two childhood-exposed samples (N = 1,975, Mage = 73.44; N = 959, Mage = 72.09) and one consisting of their children (N = 1,747, Mage = 51.67). Supporting perspectives on individual resilience, the findings revealed no significant associations between early-life war exposure and late-life adjustment. Likewise, parents' war experiences were not associated with their children's midlife adjustment. Process analyses, including socioeconomic status, control beliefs, and general stress responses only partially accounted for the observed associations. These results challenge the notion of inevitable long-term or intergenerational harm from early-life trauma and highlight the need for future replication studies examining individual differences in responses to war exposure. (PsycInfo Database Record (c) 2026 APA, all rights reserved).
The most commonly accepted scenario of early Earth includes: creation of the universe around 13.8 Ga (Giga-annus; or 109 years ago); establishment of our solar system ~ 4.60 Ga; and formation of Earth ~ 4.54 Ga. The earliest life forms on our planet so far observed to have existed, are microbes that left signals of their presence in rocks ~ 3.6 Ga - suggesting that Life forms existed within the first 940 million years after Earth's formation. However, an intriguing recent publication [1] infers that the last universal common ancestor (LUCA) likely existed by 4.2 Ga, and that the inferred LUCA had a genome of at least 2.5 Mb of DNA, encoding around 2,600 proteins; this suggests that sophisticated Life might have existed within the first 340 million years after Earth was formed. The commonly accepted geological history of early Earth suggests that the turbulent Hadean Eon lasted until 4.0 Ga, with the Late Heavy Bombardment (LHB) period occurring around 4.1 to 3.8 Ga. If Earth during the Hadean exhibited a molten surface, intense volcanic activity, and constant bombardment by asteroids and comets - how were sensitive molecules (e.g., nucleic acids, proteins) able to survive? Considering the "Lipid First" hypothesis [2], we propose that replicating lipid micelles are feasible candidates for having populated much of Earth's deep hydrothermal vents and turbulent surface within the first 340 million years of Earth's existence. These lipid micelles could therefore have provided a plausible form of "protective capsules" inside which early Life's sensitive molecules were able to evolve.
Defect functionalization is a promising route to enhance spin-orbit coupling (SOC) in graphene, but achieving controllable fluorination while suppressing irreversible lattice damage remains challenging. Here we demonstrate low-damage fluorination of monolayer graphene using a remote CF4 plasma process that suppresses ion-bombardment-induced lattice damage. Raman spectroscopy with defect-activation analysis and an annealing-reversibility test identifies a processing window where fluorination predominantly yields reversible sp3 C-F functionalization while minimizing vacancy formation. Nonlocal transport measurements show that the nonlocal resistance increases in fluorinated graphene and decays exponentially with channel length, consistent with spin diffusion and yielding a spin relaxation length of ∼0.4 μm. Within the Elliott-Yafet framework, we estimate an effective SOC energy scale of 4-9 meV. These results provide a Raman-validated, tunable process route for enhancing SOC in graphene while suppressing vacancy damage.
Hordeum brevisubulatum 'Mengnong No. 2' is a new forage variety developed using traditional group selection breeding techniques. It features notable advantages in plant height, tillering capacity, and overall biomass yield. However, key molecular breeding techniques such as molecular marker identification and genetic manipulation have yet to be established for this variety, limiting improvements in important traits. Consequently, we assessed the biomass of 'Mengnong No. 2' against 'Mengnong No. 1', the most widely cultivated variety in the central and western regions of Inner Mongolia, China. We report that fresh forage, dry forage, and seed yields of 'Mengnong No. 2' increased by 20.6%, 31.78%, and 34.35%, respectively, compared with the control variety, indicating broad prospects for its application and promotion. To enable rapid identification of 'Mengnong No. 2' during its promotion and to prevent production losses caused by variety admixture, we used three screened SSR primer pairs (GST25, GST37, GST127) to construct a DNA fingerprint for five H. brevisubulatum varieties, including 'Mengnong No. 2'. With the percentage of polymorphic bands exceeding 95%, these profiles enabled precise identification of the 'Mengnong No. 2' variety. Furthermore, callus regeneration in H. brevisubulatum represents a bottleneck for directed molecular breeding techniques such as genetic transformation and gene editing. Accordingly, we selected the inflorescences of 'Mengnong No. 2' as explants and investigated the callus induction and regeneration capacity of inflorescences at different developmental stages. We found that explants at the spikelet primordia differentiation stage exhibited the highest callus induction and regeneration efficiencies, reaching 62.7% and 72.8%, respectively. The resulting embryogenic callus lines can serve as recipients for Agrobacterium-mediated transformation or gene gun bombardment, facilitating the development of subsequent high-efficiency genetic transformation and gene-editing systems. The SSR-based variety identification system and the highly efficient regeneration technology using inflorescence-derived callus established in this study lay a solid foundation for the development of a molecular breeding system for 'Mengnong No. 2'.
Epilepsy is a multifactorial neurological disorder characterized by recurrent, unprovoked seizures. Although various diagnostic approaches are available, no single technique serves as a gold standard. Radiotracer-based positron emission tomography (PET) offers a non-invasive strategy for localizing epileptic foci. However, the currently available tracers have limited specificity and pharmacokinetic performance. In this work, report the radiosynthesis and preliminary evaluation of [18F]rufinamide as a potential PET tracer for epilepsy imaging. Microwave-assisted (µE) radiosynthesis (120 °C, 20 min) afforded quantitative conversion with a total synthesis time of 40 min from the end of bombardment (EOB), and a two-step procedure completed with 20 ± 5%, radiochemical yield and >95% radiochemical purity. The physicochemical profiling revealed a lipophilic nature (log D 7.4) and high plasma protein binding (82.5 ± 2.1%). PET imaging and biodistribution studies in normal Wistar rats confirmed brain uptake and renal clearance. These findings demonstrate that [18F]rufinamide possesses favorable radiochemical and pharmacological characteristics, supporting its potential as a novel PET probe for non-invasive imaging of epileptic brain regions.
The atomic microstructural evolution of circumstellar dust grains, which seed the interstellar medium, remains poorly understood. Amorphous alumina and its crystalline polymorphs, including corundum, have been found in the circumstellar shell of evolved stars. Evidence includes both astronomical observations of mid-infrared spectroscopic features and laboratory analyses of presolar grains. In this work, we show that electron fluxes can stimulate crystallization of amorphous alumina stardust analog materials using transmission electron microscopy. Crystallization experiments conducted at varying electron energies and flux conditions demonstrate a critical threshold cumulative electron dose of ∼1024 e-/m2 for crystallization, suggesting that the crystallization process can occur through atomic rearrangement due to electron interaction with the amorphous matrix. Throughout the crystallization process, time-resolved diffraction reveals the transition from amorphous to a transitional η-Al2O3 phase. The same transitional phase was confirmed to occur via thermal annealing at 800 °C, while annealing at 1,300 °C produced the stable crystalline phase α-Al2O3 (corundum). In both processes, the structural evolution through atomic rearrangement was characterized by quantifying the average interatomic distance between neighboring atoms using the electron pair distribution function analysis. Extrapolating to astronomical timescales, our findings suggest that electron bombardment may play a significant role in the crystallization of stardust grains, highlighting its potential importance in astrophysical environments, such as the circumstellar envelopes of planetary nebulae.
Understanding and engineering atomic defects in hexagonal boron nitride (hBN) provides a powerful platform for realizing solid-state quantum emitters and spin qubits, advancing the field of quantum information science and technologies. However, the full potential of such quantum defects remains locked by the critical lack of a deterministic structure-property relationship at the atomic scale. Here, we demonstrate a strategy to atomically engineer and decipher quantum defects in hBN by integrating scanning tunneling microscopy/spectroscopy (STM/STS) and noncontact atomic force-microscopy with a CO-functionalized tip. We implemented controllable argon ion bombardment to create both boron vacancies (VB) and nitrogen vacancies (VN) in submonolayer hBN grown on Cu(111). Simultaneously, encapsulated Ar species trapped between hBN and Cu(111) locally lift the hBN to form nanobubbles, thereby decoupling atomic vacancies from the metal substrate and enabling direct probing of their electronic states. For the on-bubble VN, STS measurement reveals a prominent in-gap state with a phonon replica. Furthermore, with aid of STM tip-assisted manipulation, we demonstrate that the tuning of nanobubble sizes modulates their strain profile, thereby modulating the energetic positions of electronic states in on-bubble defects, corroborated by density functional calculations. Our studies offer insight into the intrinsic defect structures in hBN and quantum defect engineering via local strain engineering.
Controlling the digestibility of cellulosic biomass is important for its efficient use. We generated intragenic rice plants showing enhanced saccharification yield of rice straw. The rice cytokinin biosynthesis gene, LONELY GUY, under the control of the rice senescence-inducible STAY GREEN promoter, was introduced into the rice genome via particle bombardment. The rice-derived herbicide resistance gene ALS(G95A) was used as a selection marker gene. Regenerated intragenic rice plants with no foreign sequences showed enhanced saccharification yields from the leaves at harvest, whereas no significant differences were observed at the heading stage. Because the saccharification yields of rice straw are reduced after senescence, which is suppressed by cytokinin, we propose that the enhanced saccharification yields of intragenic rice plants are caused by the delay in senescence of the rice leaves due to the expression of the introduced cytokinin biosynthesis gene upon senescence.
Artificial peptide-DNA complexes enable the transient expression of transgenes in mitochondria; however, the mechanism by which DNA is released from such complexes after delivery remains poorly understood. We previously established particle bombardment-assisted peptide-mediated gene transfer as a method for DNA delivery in plant mitochondria. In this study, we examined the effects of C-terminal modification of a mitochondria-targeting carrier peptide on transient gene expression in mitochondria. Plasmid DNA encoding NanoLuc (Nluc) was complexed with C-terminally amidated cytcox-KH (cytcox-KH-NH2) or non-amidated cytcox-KH (cytcox-KH-COOH) and delivered to Brassica campestris leaves. Introduction of the cytcox-KH-COOH-based complex considerably elevated transient Nluc activity compared to that of the cytcox-KH-NH2-based complex. Both peptides demonstrated comparable DNA-binding capacities, DNase I protection, and transcriptional activity, indicating similar interactions with plasmid DNA. However, the cytcox-KH-COOH-based complex exhibited increased susceptibility to trypsin digestion. This result demonstrates that C-terminal modification modulates transient gene expression in the mitochondria by altering the protease sensitivity of the peptide-DNA complexes. Consequently, controlled peptide degradability is a crucial parameter contributing to transient gene expression in mitochondria.
War hits the most vulnerable children hardest. In prolonged conflicts such as the one in the Gaza Strip, health and school infrastructure are destroyed, vaccinations and education are disrupted, while malnutrition and child mortality rise sharply. Psychological trauma may last for decades. The open conflict involving the United States, Israel, and Iran - a war extending beyond national borders through direct attacks, bombardments, and indirect military actions - has already produced civilian casualties and regional instability with global economic and humanitarian consequences. In this context war emerges as one of the most powerful determinants of health. Its impact extends beyond the battlefield, influencing political and economic priorities even in distant societies and diverting resources away from health, education and social development. Outrage at these tragedies is therefore not merely an emotional response but a call to moral and civic responsibility.
This study documents facility-based maternal, obstetric, and neonatal outcomes and associated conflict-related exposures and living conditions among pregnancy-related encounters at Al-Helou Maternity Hospital in Gaza from late April to early September 2025, with a small number of additional encounters recorded at Al-Shifa Medical Complex. We conducted an observational, facility-based study using a combined retrospective-prospective approach. All recorded obstetric encounters were eligible. Outpatient antenatal clinic visits were excluded. Data were abstracted from routine clinical records and contemporaneous intake forms/clinician notes. Analyses were primarily descriptive (medians [interquartile range, IQR] and counts/percentages with variable-specific denominators). Exploratory correlation analyses examined birthweight in relation to selected maternal exposures. Among 686 women (median age 28 years [IQR 23-33]), 92.9% reported ≤2 meals/day and 71.7% had anemia (Hb <11 g/dL); 78.7% were currently displaced (54.8% living in tents), 57.0% reported nearby bombing within 24 h, 98.0% had smoke exposure, and 74.6% reported heavy lifting. Only 32.1% reported access to prenatal care, 52.6% pregnancies were unplanned, and 11.9% of unplanned pregnancies reported successfully accessing contraception. Gestational age was ≥37 weeks in 80.8%. Delivery management included 57.4% normal vaginal deliveries and 37.6% caesarean sections (53.4% due to prior caesarean). Postpartum intensive care unit admission occurred in 1.0% with 28.6% mortality among those admitted. Neonatal outcomes (n = 665) included median birthweight 3000 g (IQR 2600-3300), neonatal intensive care unit (NICU) admission 12.9%, discharge alive 98.6%, and last documented Apgar score of 10 in 43.0% (0 in 9.5%). Pregnancy-related encounters in Gaza occurred amid pervasive food scarcity, displacement, smoke exposure, and recent bombardment, alongside high anemia prevalence and limited prenatal care. Maternal care featured substantial caesarean use and severe maternal complications, while neonatal outcomes included frequent NICU admission, underscoring a high-risk environment for mothers and newborns.
A comparison among three models (Birattari Conic Plume, HotSpot, and NCRP 123 Gaussian distribution) has been carried out concerning the release of air-activated radionuclides during bombardment of a H 218 O target in a medical cyclotron with two different proton energies: 10 MeV and 18 MeV. Under worst-case meteorological conditions, the diffusion of 13 N, 40 Cl, 37 S, and 41 Ar has been investigated. The total amount of induced activation (Bq) during different beam times has been calculated for each isotope, and the three models have been used to assess the dose to the residential population located 100 m from the release point, for a fixed beam current of 100 µA. The results demonstrate that a facility for medical isotope production, even under heavy workload (3,000 µA h -1 wk -1 ), will not lead to a significant increase in the dose to the surrounding population.
Functionalization of transition metal dichalcogenides is a key process for future technological applications. To date, various routes, primarily chemical, have been proposed for efficient functionalization with thiol moieties. Previous functionalization protocols have generally taken advantage of intrinsic defects typically present on the surface. However, the specific nature of the molecule-substrate bond, covalent or noncovalent, has always remained controversial. In this work, we present a study of the functionalization of MoS2 by physical vapor deposition in ultrahigh vacuum conditions of the 4-aminothiophenol molecule. We have investigated its interaction with the intrinsic sulfur vacancies present in MoS2 and with additional vacancies generated by ion bombardment. We observe that the molecule is found in planar configuration on the surface and the thiol moiety remains intact. Atomic force microscopy measurements show high diffusion of molecules through the surface, along with a strong interaction between the thiol moieties and the tip itself. Interestingly, this interaction leads to a contrast inversion in the acquired AFM images, which is a key observation that leads to consider that molecules are not covalently bonded. Density functional theory calculations rule out thiol dehydrogenation, attributing the observed contrast inversion to molecular tip functionalization. These findings provide compelling evidence of a nonspecific physisorption interaction, confirming the absence of covalent bonding between the molecule and the surface.
Data-driven approaches have accelerated materials discovery, yet they often remain "black boxes" that prioritize performance over physical understanding. To bridge the gap between statistical correlation and physical causality, this study establishes an interpretable machine learning (IML) framework applied to the sputter deposition of Mo-doped In2O3 thin films. Unlike conventional predictive models, our approach uses XGBoost regression combined with feature-importance analysis to quantitatively decouple the entangled effects of deposition parameters. Crucially, the model autonomously discovered─without explicit prior knowledge─that the carrier density is governed by oxygen partial pressure (PO2), while electron mobility is driven by crystallinity depending on the trade-off effects between adatom diffusion and high-energy particle bombardment. We experimentally validated these ML-derived hypotheses, identifying that the PO2 dependence stems from defect compensation by interstitial oxygen rather than simple oxygen vacancies and that the mobility peak corresponds to optimal crystallinity. This work demonstrates that IML can effectively "rediscover" governing physical laws from small experimental data sets, offering a scalable strategy to elucidate growth mechanisms in functional materials.
Biolistic particle bombardment was used to deliver CRISPR-Cas9 ribonucleoprotein complexes (RNP) into the shoot apical meristem tissue of citrus and axillary meristem tissue of poplar, generating directed mutations in target genes. The use of meristematic tissues offers a strategic approach to genome editing in woody species, especially those that are recalcitrant to conventional tissue culture, as these regions contain totipotent, highly regenerative cells capable of giving rise to whole plants. Here, we employed biolistic delivery of genome-editing reagents into theshoot apical meristem (SAM) of citrus and the axillary meristems (AXM) of poplar. The system was first validated using a GFP expression construct and subsequently applied for targeted genome editing. In citrus, edited plants were obtained at the CsNPR3 locus exclusively through the delivery of CRISPR/Cas9 ribonucleoproteins (RNPs), whereas plasmid-based vectors were unsuccessful. Similarly, genome editing in poplar was achieved using RNPs targeting the Pt4CL1 gene. Although chimeric events were detected, this approach provides a feasible and innovative framework for producing transgene-free edited perennial plants.
The deliberate functionalization of defects represents a largely unexplored frontier in advanced optoelectronics. Within Einstein's photoelectric framework, we elucidate how deep-level defects in CsPbBr3 films act as functional mediators to govern carrier transport, interfacial electron escape, and quantum efficiency multiplication via a defect-mediated tunneling process. First, in solid-state photonics, it overcomes strong exciton binding in an Au/CsPbBr3/Au transistor, yielding a >70-fold photoconductive gain at sub-nA dark current and a spectral response extension of >0.88 eV. Second, in vacuum electronics, electron beam bombardment creates localized electropositive centers, forming a defect-functionalized activation layer that induces pronounced band bending and shifts interface dominance from luminescence to photoemission, offering a robust alternative to chemical methods. Thirdly, we demonstrate transient quantum efficiency multiplication that reaches 16.8% under 266 nm pulsed excitation and achieves a 34 dB gain at 355 nm, functionally establishing a photoemissive comparator. By transforming the conventional role of defects from detrimental to functional, this work represents "defect-functionalized optoelectronics" as an alternative design route for advanced nonlinear device function.