Browse Articles

Epitope-spanning antigenic variation reprograms immunodominance and broadens immunity in sequential influenza vaccination

Single‐Atom and 1 nm Cluster Co‐Modified Thermoelectrics

ABSTRACT The size‐dependent electronic and phononic configurations of single atoms and nanoclusters enable tailored functionalities. Their synergistic effects also attract attention, yet precise control of anti‐aggregation states during high‐temperature operations poses formidable challenges in multiple fields such as fuel cells and thermoelectrics. Herein, we develop a solution‐processed strategy to precisely incorporate Pt species as isolated atoms (Pt 1 ) and sub‐nanoclusters (Pt n , ∼1 nm) in Bi 2 S 3 . Notably, Pt n of 1 nm size exhibit significant advantages over larger‐size counterparts in tuning electronic structure and optimizing charge transfer. Furthermore, Pt 1 and Pt n scatter 1 Å‐ to 1 nm‐ wavelength phonon that is conventionally underexplored. The 1 nm Pt n exhibits distinct force constant as compared to 3 nm Pt n , leading to ultra‐strong phonon Rayleigh scattering, which in turn significantly reduces thermal conductivity. The optimized Bi 2 S 3 ‐Pt 1 /Pt n composite achieves breakthrough thermoelectric performance, attaining a maximum zT of 1.02 at 773 K and single‐leg conversion efficiency of 1.58%, both setting benchmarks for Bi 2 S 3 systems. This strategy can also be extended to other thermoelectric material systems such as Bi 0.4 Sb 1.6 Te 3 , PbTe, or other fields including solid‐state batteries and solar cells.

Vaping and mental health: A cross-sectional study among university students in Bangladesh

Introduction Vaping has continued to rise, besides smoking, among youth in Bangladesh in recent years. While there has been evidence of the impact of vaping on physical health, studies focusing on mental health specifically from the South Asian context are almost non-existent. Therefore, this study examines the association between vaping and a spectrum of mental health issues, such as psychological distress, depression, and anxiety, among university students in Bangladesh. Methods A cross-sectional study with undergraduate students, aged 18−25 years, from seven universities in Bangladesh, was conducted. Data were collected using a web-based questionnaire. Data on smoking, vaping, and dual use were collected. Psychological distress was measured by using the K10 scale, while the CES-D10 and GAD-7 scales assessed depression and anxiety, respectively. Univariate and multivariate logistic regression analyses determined the relevant associations. Adjusted Odds Ratios (AORs) and 95% Confidence Intervals (CIs) were reported. Results Of the 1615 study participants, males and females were distributed equally, and 54% were from two private universities. Findings revealed that one in six (15.4%, n = 248) participants were currently vaping. Exclusive current smokers were 6.2%, exclusive vape users were 6.5%, and dual users were 8.9%. Among vape users, the prevalence of psychological distress (80.5% vs. 76.6%) and depression (63.8% vs. 60.8%) was higher among dual users compared to current vape users; anxiety was similar (56.9% vs. 57.6%) in both groups. After adjusting potential confounders, current vaping was associated with drinking alcohol (AOR 11.43, 95% CI 7.41–17.63) and used of recreational drugs (AOR 4.29, 95% CI 2.36–7.79) However, dual use was associated with higher depression (AOR 1.93; 95% CI 1.04–3.57) and without a preexisting mental health condition was associated with severe anxiety (AOR 2.00, 95% CI 1.25–3.20). Conclusion The study underscores a concerning impact on mental health amongst the young group of the population who were vaping, specifically among the dual users. Besides raising awareness, university-based tobacco cessation support and counselling should be considered a student well-being support strategy.

Stress-induced iron-sulfur cluster damage as a conserved trigger of the bacterial stringent response

A Facile Neutral Nickel Catalyst Platform for High‐Temperature Solution Copolymerization of Ethylene and Acrylate

ABSTRACT Polyolefins are among the most important large‐scale polymers. High‐temperature solution polymerization is one of the most effective methods for preparing high‐performance polyolefins. Although advanced high‐temperature solution copolymerization of ethylene and polar olefins (especially acrylates) is highly desirable for producing value‐added polar polyolefins, it poses significant challenges in chemistry and catalysis, including low catalyst thermostability and low polymer molecular weight at temperatures exceeding 100°C. To address these issues, this study proposes design principles for an innovative neutral α‐ketocarboxamide nickel catalyst platform rather than modifying previously reported nickel catalysts. This new generation of nickel catalysts not only offers inherent advantages, including facile synthesis, air stability, and exceptional thermostability (150°C), but also enables high‐temperature solution copolymerization of ethylene and acrylates (methyl, n ‐butyl, and tert ‐butyl acrylates), producing high‐molecular‐weight copolymers without the need for cocatalysts. At the industrially preferred 110°C–150°C, ethylene–acrylate copolymers with molecular weights of 103–627 kDa were obtained, which are 4–19 times higher than those produced by previous catalysts. Transitioning from low‐ to high‐molecular‐weight ethylene–acrylate copolymers is vital for practical industrial applications. Mechanistic insights revealed the feasibility of ethylene–acrylate copolymerization. Overall, this study establishes a conceptual foundation for high‐temperature solution copolymerization of ethylene and acrylates.

Motivation and determinants of research careers among physicians: Exploring pros and cons of the Dutch MD-PhD model

Introduction Training pathways, such as MD-PhD-programs, have been established to increase the physician-scientist workforce. Still, MD-PhDs represent only a small fraction of the physician workforce worldwide. This is different in the Netherlands, where half of specialist physicians hold a PhD, but little is known about their careers. We aimed to explore the motivations of Dutch physicians to pursue a PhD, and investigate the proportion of MD-PhDs entering physician-scientist careers. Methods In 2022, we conducted a survey study among all MD-PhDs in the Netherlands who obtained a PhD degree in the year 2008. Drawing on self-determination theory, we used the Motivation for PhD Studies Scale to assess respondents’ motivations for pursuing a PhD. We defined a physician-scientist career as spending at least 20% of working hours on both research and clinical work. Results Of all 479 MD-PhDs, 240 completed the survey (response rate 56.6%). Motivation for a physician-scientist career appeared to be predominantly driven by autonomous motivation (including intrinsic and internalized forms of extrinsic motivation), rather than controlled motivation (reflecting external and internal pressures). Of all respondents, 67.5% reported a combination of clinical and research activities. One quarter (25.2%) met our criteria for a physician-scientist career, similar between men and women. Higher scores for autonomous motivation were associated with continued research activity, including a physician-scientist career and tenured appointment. The motivation to pursue research and having a scientific network or research collaborations were mentioned as supportive factors for continuing research after the PhD. The lack of dedicated time for research and a desire to spend more time with one’s partner or family were the most important barriers against continued research activities. Conclusions Autonomous motivation is more important than controlled motivation for Dutch physicians in pursuit of a PhD, and is associated with an increased likelihood of a subsequent physician-scientist career. Of the large proportion of MD-PhDs in the Dutch physician workforce, one fourth continues as physician-scientist.

Fine-scale structure of a whole regional population through genetics and genealogies

Steering Zeolite Brønsted Acidity and Catalytic Consequence Through Manipulating the Coordination Environment of Framework Aluminum

ABSTRACT The strong acidity of Brønsted acid sites in zeolites often leads to uncontrollable reactions and rapid deactivation. Therefore, strategically weakening zeolite acidity is essential for balancing reactivity with stability. The local coordination environment of framework aluminum usually governs its acidity. Hydroxylation of framework aluminum is often inevitable under high‐temperature and humid “working” conditions; however, the impact of hydroxyl coordination on the relevant acidity and catalytic behavior remains unclear. Here, we demonstrate how hydroxylation of framework aluminum strategically moderates acidity and enhances catalytic stability. Density functional theory (DFT) calculations predict that an increase in the hydroxyl groups coordinated to framework aluminum leads to a progressive weakening of Brønsted acidity. We experimentally validate this prediction by precisely manipulating hydroxylation in ZSM‐5 zeolite via steaming treatment and analyzing the effects using 2D NMR spectroscopy with 2– 13 C‐acetone as a probe molecule. The hydroxylated aluminum sites exhibit reduced adsorption and activation of methanol in the dehydration reaction, consistent with their weaker acidity. Catalytic tests reveal that the hydroxylated samples significantly enhance catalyst lifespan in the MTO process, while preserving stable reactivity. These findings provide key insights into how coordination perturbations influence zeolite acidity and catalytic performance, offering valuable guidance for designing zeolites with targeted catalytic functions.

Correction: Distinct Distal Gut Microbiome Diversity and Composition in Healthy Children from Bangladesh and the United States

Audio long read: Many people have no mental imagery. What’s going on in their brains?

Extreme longitudinal thermal conductivity and non-diffusive heat transport in isotopic hBN

Abstract We measure the temperature profile and investigate the thermal conductivity of suspended monoisotopic hexagonal boron nitride (h 10 BN) heterostructures by combining suspended microbridge technique and Raman spectroscopy. The thermal conductivities exceed 1650 W.m −1 .K −1 at room temperature, significantly higher than in previous reports, highlighting the crucial influence of the measurement conditions on the experimental results. By including more data points, we refine our models beyond the accuracy of conventional approaches. Our results show a striking deviation of thermal transport from the classical diffusion regime described by Fourier’s law: while the temperature profiles are linear above 300 K, they become clearly nonlinear below this temperature, indicating a strong non-diffusive heat transport regime. This behavior underscores the need for a new theoretical framework to fully account for heat transport in two-dimensional materials. Ultimately, our findings pave the way for innovative heat dissipation technologies and challenge conventional paradigms in nano-heat engineering. This study establishes a practical framework linking Raman-based temperature mapping, the number of measurement points, and thermal simulations to reliably determine the in-plane thermal conductivity of 2D materials.

Electron Transfer Mediator–Enabled Modular Control of ¹ O ₂ and O ₂ ^•– Generation in Porphyrin Supramolecular Frameworks for Selective Photosynthesis

ABSTRACT The inherent preference of classical type II photosensitizers for generating singlet oxygen ( 1 O 2 ) via energy transfer presents a key challenge in developing type I systems capable of producing superoxide radicals (O 2 •– ) through electron transfer. Herein, we report a porphyrin‐based supramolecular organic framework (SOF, TPP‐BPY‐CB[8]) assembled via host–guest interactions with cucurbit[8]uril (CB[8]), which achieves a significantly enhanced 1 O 2 quantum yield (94.04%) compared to the monomeric unit TPP‐BPY (74.52%). To overcome the energy transfer‐dominated reactive oxygen species (ROS) pathway, a series of electron transfer mediators were introduced to modulate the excited‐state dynamics, resulting in BQ@TPP‐BPY‐CB[8] that effectively switches the ROS pathway from type II to type I. This mediator‐driven modulation not only enables O 2 •– production under hypoxic conditions but also expands the functional diversity of the SOF system. The two ROS pathways are selectively leveraged in photocatalytic applications: TPP‐BPY‐CB[8] excels in 1 O 2 ‐mediated oxidation of organophosphorus compounds, while BQ@TPP‐BPY‐CB[8] facilitates highly efficient thiol‐ene cross‐coupling via O 2 •– promotion. This work presents a robust strategy for tailoring ROS generation in supramolecular photocatalysis, offering a new design paradigm for multifunctional, ROS‐directed photoreactive materials.

Maternal hyperuricemia and adverse neonatal outcomes in normotensive pregnancies: Evidence from a prospective cohort study in Eastern Uganda

Background Maternal hyperuricemia is a potential biomarker of adverse pregnancy outcomes, but evidence among normotensive women in low- and middle-income countries is limited. We aimed to assess the association between elevated maternal serum uric acid (SUA) levels and adverse neonatal outcomes. Methods We conducted a prospective cohort study at Jinja Regional Referral Hospital, Uganda, from 1 st October 2024–1 st February 2025, enrolling 352 normotensive women in latent labor. SUA was measured using gestational-age–specific cutoffs, classifying women as hyperuricemic or normouricemic. Outcomes included preterm birth, small-for-gestational-age (SGA) birth, stillbirth, and low Apgar score. Poisson regression with robust standard errors estimated adjusted relative risks (aRR) and 95% confidence intervals. Results Adverse neonatal outcomes occurred in 37.5% of participants. Hyperuricemic women had significantly higher composite risk (62.5% vs. 12.5%; aRR = 4.32, 95% CI 2.92–6.39). Hyperuricemia independently predicted preterm birth (aRR = 3.63, 95% CI 1.70–7.72), SGA (aRR = 2.80, 95% CI 1.61–4.86), and stillbirth (aRR = 5.00, 95% CI 1.47–16.99). Maternal age ≥ 40 years, low education, < 4 antenatal visits, previous preterm birth, previous stillbirth, and obesity were also associated with adverse outcomes. Conclusions. Maternal hyperuricemia is a strong predictor of preterm birth, SGA, and stillbirth. Routine SUA screening during antenatal care, combined with closer monitoring of high-risk women, could help improve neonatal outcomes.

Enantiospecific Optical Sensing of Terpenes by an Aggregated Atropisomeric Platinum(II) Complex

Abstract Terpenes are unfunctionalized small volatile organic compounds (VOCs) that are naturally abundant, relevant to climate change, and impose potential health risks. Herein, we report a conceptually novel approach for the enantiospecific recognition of terpenes and other VOCs based on a square planar platinum(II) complex with an atropisomeric ligand. This molecular design results in chiral aggregated nanostructures caused by weak π‐π‐ and metal–metal interactions with characteristic UV–vis absorption bands. Distinct UV–vis absorption changes are induced by weak intermolecular interactions with the enantiomers of diverse VOCs (2‐butanol, 1‐phenylethanol, α‐pinene, and limonene) leading to perturbations of the chiral aggregates. This allows an enantiospecific, reversible detection of VOCs by UV–vis absorption spectroscopy in nonpolar solution. The study provides a new working principle for enantiospecific recognition with artificial optoelectronic noses, which are particularly promising for determining the enantiomers of unfunctionalized volatile organics.

Social inequities and clinical outcomes in young women with cervical cancer: Real-world evidence

Objective To assess the influence of social inequities and clinicopathological factors on survival outcomes in young women with cervical cancer treated at a comprehensive public cancer center in Brazil. Methods This retrospective analysis reviewed the medical records of women aged 18–39 diagnosed with cervical cancer at the Brazilian National Cancer Institute between January 2017 and December 2021, assessing demographic characteristics and survival outcomes. Results This analysis included 475 patients with a mean age of 33.6 years, with the majority being non-white (67.7%), never married women (68.0%), and having a low education level (< 8 years) (86.1%). Multivariate analysis indicated that a lower education level was associated with advanced stage (p = 0.001). Recurrence or progression occurred in 224 patients (47.2%), mainly as distant metastases (56.7%). The median progression-free survival (PFS) was 19.8 months, with two-year rates of 81.6%, 45.7%, 28.2%, and 6.2% for stages I, II, III, and IV, respectively. Shorter PFS was correlated with lower education level (p = 0.009), alcohol consumption (p = 0.026), undifferentiated carcinoma (p = 0.007), and advanced disease stage (p < 0.001). The median overall survival (OS) was 35.1 months, with five-year rates of 82.9%, 42.7%, 23.7%, and 9.7% for stages I, II, III, and IV, respectively. Factors associated with shorter OS included lower education level (p = 0.005), undifferentiated carcinoma (p = 0.006), and advanced stage (p < 0.001). Conclusion Undifferentiated carcinomas and advanced stages negatively influence the prognosis of young women with cervical cancer. Social factors may also be correlated with poorer outcomes, especially alcohol consumption and lower education levels.

Dual‐Site Geometry Mediates Dynamic LiO ₂ Binding for Efficient Lithium–Oxygen Batteries

ABSTRACT Lithium–oxygen batteries (LOBs) offer high energy density through multi‐electron transfer, but their 2e − pathway generates unstable intermediates such as lithium superoxide (LiO 2 ), leading to complex reaction kinetics and poor reversibility. Herein, we propose an electronegativity‐mediated strategy to dynamically regulate LiO 2 binding on catalyst surfaces. By tuning the geometry and spacing of dual‐active sites (DAS), we reshape orbital interactions and coordination environments, enabling precise control over electron density and adsorption‐desorption microenvironments. This atomic‐scale regulation establishes a “bridged adsorption” mode that stabilizes key intermediates, optimizes Li‐O bond activation, and enhances the “adsorption‐activation‐dissociation” sequence of reactive species. Consequently, lithium–oxygen batteries exhibit high capacity and prolonged cycling stability. More broadly, we identify a universal DAS spacing descriptor that integrates symmetry breaking with electronic configuration, providing a general design principle to overcome linear scaling relationships (LSRs) and unlock intrinsic catalytic activity for oxygen electrocatalysis.

Revealing undergraduate biology students’ conception of variability and error bars within graphing

Creating and interpreting graphs are quantitative reasoning skills all science, technology, engineering, and math students need to develop. In biology, data are lacking in our understanding of how undergraduate students interpret variability across different graph types or what knowledge students have about the data error bars represent. This study analyzed 3506 student responses within a graphing assessment. We developed a code book for students’ open-ended responses on the data error bars represent and used chi-square tests to look for significant differences in how students described error bars based on a graph they created and self-reported demographic data. We observed four major categories in how students described error bars: broad terms, error terms, purpose terms, and trend & analysis terms. When responses were linked with a graph the student made, those who created a bar graph with a bar for each data point showed lower understanding of error bars compared to students who themselves created a bar graph with aggregated means and error bars. We also observed differences in how students described error bars based on their major but did not observe differences based on whether students were in introductory or upper-level courses. Our results suggest that students are not receiving enough instruction on variability within graphing even though bar graphs with error bars are a common graph that students are asked to construct. More scaffolded repeated instruction is needed across biology curricula.

Temperature‐Potential Coupled Regulation of LiPF ₆ Decomposition to Construct LiF Grain Boundary‐Rich Interphase on Graphite Anode for Fast‐Charging Li‐Ion Batteries

ABSTRACT Regulating the electrolyte decomposition to evolve a LiF‐rich solid‐electrolyte interphase (SEI) can reduce the energy barrier of the interfacial Li‐ion transport toward fast‐charging lithium‐ion batteries. Due to the sluggish decomposition kinetics, LiPF 6 , as a widely used Li salt in commercial cells, is unable to build a LiF‐rich SEI. Therefore, expensive fluorinated electrolyte additives are needed. Herein, to eliminate the use of extra fluorinated species, based on the subtle electrochemical decomposition of LiPF 6 occurring ∼2.28 V vs. Li + /Li at 80°C, we developed a temperature‐potential coupled formation (TPCF) protocol, which incorporates a constant‐voltage step (2.28 V) at 80°C to stimulate LiPF 6 decomposition deeply, thereby generating a high‐quality SEI uniformly covering the graphite particle surfaces. This TPCF‐derived SEI is thin and dense, full of LiF grain boundaries, which could reduce the energy barriers of Li + desolvation and interfacial Li + diffusion. Simultaneously, this SEI exhibits a higher work function, effectively suppressing electron leakage to reduce the degeneration of the electrolyte and interphase. Consequently, after a simple TPCF process, the assembled graphite||LiFePO 4 full cell achieves stable cycling at a 6C rate, retaining 80% of its capacity after 3304 cycles and 70.5% after 8940 cycles, outperforming the counterparts.

Effects of fibroblast growth factor 2 on muscle precursor cells from mouse limb and extraocular muscle

Fibroblast growth factor 2 (FGF2) is known to play a role in skeletal muscle development and growth. We examined two populations of myogenic precursor cells for their responses to FGF2 in vitro using both extraocular and limb skeletal muscle. Fluorescence-activated cell sorting (FACS) was used to isolate two different populations of myogenic precursor cells, the EECD34 cells (positive for CD34, and negative for Sca1, CD31, and CD45) and PAX7-positive cells, from tibialis anterior and extraocular muscles of mice. These cells were cultured and treated with either proliferation or differentiation media in the absence or the presence of FGF2, followed by assays to determine the effects on proliferation and differentiation. EECD34 cells and PAX7-positive cells from both muscles responded to FGF2 with significantly increased proliferation. Both myogenic precursor cell populations from each muscle type showed increased percentage of desmin-positive mononucleated cells, but decreased rates of fusion into multinucleated myotubes in the presence of FGF2 in this in vitro system relative to control cells. FGF2 has pleiotropic effects on skeletal muscles. Contrary to the literature, FGF2 did not inhibit differentiation, but did appear to decrease fusion into multinucleated myofibers in vitro . Examination of immunostaining for myomerger in differentiating PAX7-positive cells in the presence or absence of FGF2 demonstrated a significant reduction of expression in the presence of elevated FGF2 levels. These results provide a potential mechanism for reduction in myofiber number and size in the extraocular muscles in individuals with Apert syndrome, where FGF receptor 2 mutations maintain the receptor in an activated state resulting in significantly reduced myofiber size.

Unveiling the Superior Birefringence Property of a Record‐Birefringent Crystal with Unique Building Block

Abstract Despite being crucial for various advanced optical components, obtaining optically anisotropic crystals with giant birefringence (e.g., Δ n  ≥ 1.0) remains a formidable challenge. Prevailing strategies typically rely on enhancing the π‐delocalization of molecular building blocks by cyclic polymerization. Here, we demonstrate a new approach—simply connecting the π‐conjugated rings along a specific direction via linear polymerization. This concept is well exemplified by a novel hybrid crystal, BIQCdCl 4 (BIQ = C 18 H 14 N 2 , the protonated form of 2,2′‐biquinoline). Although in accordance with Hückel's rule, the π‐electrons within two quinoline subunits are not fully delocalized over the entire BIQ molecule, this compound exhibits a record‐high birefringence value of Δ n exp  = 1.017@546 nm, surpassing all commercial birefringent crystals and many newly developed birefringent crystals, thereby setting a new benchmark for such materials. Detailed electronic structure investigation indicates that while the C─C linkage limits π‐delocalization extension, linear polymerization enhances the disparity in the in‐plane ( X , Y ) π‐electron distribution, thereby maximizing the polarizability contrast between two specific polarization directions (i.e., Y and Z ). This leads to exceptional polarizability anisotropy of the BIQ molecules, which, combined with their uniform alignment directed by [CdCl 4 ] tetrahedra and hydrogen bonding, ultimately results in the giant birefringence of BIQCdCl 4 .