Browse Articles

Physical encounters impose a consistency–amount trade-off on bacterial group formation in marine environments

Physically associated bacterial groups can enhance resilience through emergent traits, including access to inaccessible substrates, increased stress tolerance, and reduced predation. These traits arise from physical and chemical interactions between cells and constitute multicellular behavior, yet we lack general principles predicting when this form of multicellularity provides ecological advantages. Here, we examine how the size of bacterial groups influence encounters with two particle types: resources and lytic bacteriophage. Using a size-dependent encounter theory, we identify regimes where encounter rates depend on group size. Experiments with the group-forming marine bacterium Vibrio splendidus 12B01 confirm that larger groups encounter particles more frequently. However, increasing group size reduces both the mean and variance of particle encounters per cell, revealing a trade-off between the consistency and amount of resource encountered. Stochastic simulations support this trade-off and predict conditions under which consistent encounters with resource particles benefit groups more than single cells, and where multicellular behaviors can alleviate resource limitation within groups. Simulations of encounters with phage-like particles predict that consistent encounters can stabilize the average time to infection for individual cells—the livable timescale—by disrupting viral replication and burst feedback. Overall, our results suggest that bacterial group formation can support resource acquisition despite predation. We predict that this advantage emerges in fluctuating fluid environments and is constrained by size- and concentration-dependent encounter physics. More broadly, these findings identify a simple physical mechanism through which multicellular groups may provide ecological advantages across diverse microbial systems.

Superconducting coherence boosted by outer-layer metallic screening in multilayered cuprates

Abstract In multilayered high- T c cuprates, the inner CuO 2 planes (IPs) are spatially separated from dopant layers and thus remain cleaner than the outer planes (OPs). Here, we investigate five-layer (Cu,C)Ba 2 Ca 4 Cu 5 O y (Cu1245) and three-layer Ba 2 Ca 2 Cu 3 O 6 (F,O) 2 (F0223) using angle-resolved photoemission spectroscopy (ARPES) and uncover an unprecedented situation, in which only the IPs become superconducting while the OPs remain metallic at low temperatures. Our model calculations indicate that over 95% of the OP wavefunction remains confined to OP itself, rendering superconducting proximity negligible. This interlayer decoupling realizes an ideal configuration—a single superconducting CuO 2 layer screened from the dopant layer-induced disorder by heavily overdoped metallic OPs. The clean CuO 2 layer exhibits a large superconducting gap with coherent Bogoliubov peaks extending beyond the antiferromagnetic zone boundary, and a widely extended coherent flat band at the Brillouin zone edge. These findings introduce the “degree of screening” as a physical parameter for probing competition between pseudogap and superconductivity, and for bridging typically disordered real materials with the idealized theoretical models.

HIV-1 capsid interactions with Nuclear Pore Complex components support nuclear entry via affinity gradient

Before entering the nucleus, the HIV capsid core [composed of capsid (CA) proteins] must translocate through the Nuclear Pore Complex (NPC). This process relies on direct interactions between CA and the phenylalanine-glycine (FG) repeats in nucleoporins (NUPs) within the NPC. FG repeats are generally classified into three canonical motifs: FG, GLFG, and FxFG, which are differentially distributed along the NPC axis: FG and FxFG motifs are predominantly at the cytoplasmic periphery and in the nuclear basket, whereas GLFG motifs are primarily in the central channel of the NPC. We demonstrate that the capsid engages the diverse FG repeats with markedly different affinities. Notably, GLFGs of NUP98 located in the central channel display significantly increased affinity to CA than conventional FGs/FxFGs. NUP153, which is located at the nuclear basket, contains an atypical FxFG that is adjacent to a PSGV sequence, thus forming additional favorable interactions. We designate this nonconventional FxFG motif as an “FG super-motif.” In addition, the C-terminus of NUP153 also contains a cluster of basic residues that serve as an enhancer of the NUP153 FG super-motif, dramatically increasing CA affinity by ~1,000-fold. Other binding enhancers for FG motifs were also identified in NUP58 and POM121 that are in the central channel and its nuclear boundary, respectively. Affinities of NUP58, POM121, and NUP153 enhancers to CA increase with proximity to the nuclear basket. Thus, we propose that the diverse FG repeats and their binding enhancers create an affinity gradient that potentiates HIV capsid translocation through the NPC.

Author Correction: Species- and variant-specific ACE2 compatibility shapes SARS-CoV-2 spillover potential in North American cervids

Tropical forests are facing increasing risks of exposure to critical temperature thresholds

Understanding how close tropical tree species are to critical temperature thresholds that might impede photosynthetic activity is vital in a world where heat waves have become more severe and frequent. Using remotely sensed surface temperature and species distribution maps, we studied the spatiotemporal variation in the thermal safety margins (TSM, i.e., the difference between T crit , the critical photosynthetic temperature, and the maximum canopy temperature) of 208 tropical tree species in South America, Southeast Asia, and Central Africa during the period 2001–2020. Despite overall high-temperature tolerance with an average T crit of 46.1 ° C, we observed a consistent decline in the TSM of tropical forests across the globe. The average pantropical TSM decline was 0.4 ° C per decade, with the strongest decline in South America ( 0.5 ° C per decade). Over the 20 -y period, areas that experienced canopy temperatures surpassing the average T crit across reported species increased from 43 Mha to 57 Mha in the tropics, representing 4 % of the studied area. This number increases to 10 % when computing areas where temperatures have surpassed the T crit of the most vulnerable reported species. When considering future trends, as predicted by Earth System Models under medium-to-high emission scenarios, average T crit may be exceeded in an area of 83 Mha by 2050 and 160 Mha by 2100 (over 10 % of the studied area), suggesting major feedback to the global carbon cycle and the world’s biodiversity.

Covalent Ag-holey MXene link at interface boosting electrochemical dechlorination

Abstract Incorporating Ag species into conductive matrices can mitigate volumetric expansion and stabilize electrode structures in capacitive deionization (CDI). Yet, this approach may suffer from severe charge transfer resistance at their heterogeneous interface featuring physical contact or weak intermolecular link. To tackle this challenge, we linked Ag single atoms and nanoparticles covalently to holey MXene (HMX) via an in situ etching-and-reduction strategy, in which atomically dispersed Ag in covalent bond with HMX is generated and serves as pivots to guide growth of Ag nanoparticles. The elaborate covalent link promotes Ag-to-HMX electron transfer and creates electron-deficiency on Ag that facilitates faradaic dechlorination. Meanwhile, the perforated HMX nanosheets with rich in-plane nanopores assemble into thin films possessing a spatially interconnected porous matrix, enabling fast cross-film transfer of both electrons and ions. Consequently, the as-made hybrid electrodes exhibit enhanced dechlorination capacity (156.63 ± 2.6 mg g −1 ), charge efficiency (91.2 ± 4.5%), and cyclic stability (>90% retention in 50 cycles) compared to the control samples. This synthetic strategy integrates Ag-mediated covalent interfacial bridging with pore-engineered MXene, providing a paradigm for designing CDI dechlorination electrodes.

The role of nonfinancial factors in the Congressional Budget Office’s health insurance coverage projections

Nonfinancial factors play an important role in people’s coverage decisions as premiums, cost sharing, and other factors that determine the financial value of health insurance cannot fully explain patterns in take-up rates. The Congressional Budget Office (CBO) is tasked with estimating the budgetary and coverage effects of policy and economic changes that affect health insurance markets, which includes considering the interactions between nonfinancial factors and policy design. The agency groups the nonfinancial factors it considers into three categories: ease of enrollment, awareness, and attitudes. Many recent policies have affected nonfinancial factors related to the take-up of Medicaid and marketplace insurance, such as the introduction of work requirements for Medicaid and access to zero-premium marketplace plans. This article explains how nonfinancial factors are handled and incorporated into CBO’s baseline health insurance projections and cost estimates, highlights the recent literature on the effect of these nonfinancial factors on insurance take-up decisions, and suggests future areas of research.

Surface-confined protection stabilizes pre-annealing crystallization for ambient blade-coated perovskites

Small but mighty: The outsized role of small water bodies in the global carbon cycle

4D force patterning enables spatial control of angiogenesis

Engineering organized microvascular networks remains a critical challenge in tissue engineering and regenerative medicine. While biochemical approaches for patterning angiogenesis via growth factor delivery have shown promise, their inability to pattern sustained growth factors with spatiotemporal control limits effectiveness. Here, we demonstrate that dynamically patterned mechanical forces enable precise spatiotemporal control over angiogenic sprouting. We developed a magnetically actuated human vessel-on-a-chip platform that integrates a perfusable endothelialized microchannel within a collagen matrix and allows noninvasive and tunable mechanical stimulation across three spatial dimensions and time (4D). Using an automated 3-axis actuator, we systematically investigated how strain magnitude, frequency, and direction modulate endothelial cell behavior and vessel morphogenesis. Dynamic mechanical stimulation at physiological strain magnitudes (5 to 15%) enhanced endothelial alignment and barrier function while promoting angiogenesis in a strain magnitude–dependent manner: lower dynamic strain (5%) maximized sprout initiation, whereas higher dynamic strain (15%) promoted elongation of sprouts. Sequential reorientation of strain direction reprogrammed sprouting trajectories along X, Y, and Z directions, generating complex sprout geometries such as L-shaped branches. RNA sequencing revealed mechanically induced transcriptional profiles distinct from unstimulated controls, characterized by upregulation of genes associated with angiogenesis, mechanotransduction, and extracellular matrix remodeling. Functional perturbation of PIEZO1 reduced strain-induced sprouting without altering barrier function, indicating that dynamic mechanical stimulation engages multiple mechanotransduction pathways to regulate angiogenesis. Collectively, these findings establish a strategy for spatiotemporally controlled angiogenesis through 4D force patterning to program vascular morphogenesis while preserving function. This approach provides a foundation for engineering hierarchically organized vascular networks for tissue regeneration.

Magnetically actuated microrobotic system for sequential treatment of biofilm

Biofilm-associated infections present a critical therapeutic challenge due to antibiotic resistance and impaired tissue healing. Here, we present a microrobotic system (MZ-8) that integrates real-time human-steered navigation with autonomous, microenvironment-responsive therapy to actively eradicate biofilms and promote tissue regeneration. This microrobotic system features a spine-inspired structure for mechanical biofilm disruption, a pH-responsive ZIF-8 coating for immunomodulatory Zn 2+ release, and closed-loop actuation under second near-infrared fluorescence guidance. In a rat model of periprosthetic joint infection, MZ-8 achieved effective biofilm removal, induced a pro-regenerative immune response by polarizing macrophages toward the M2 phenotype, and significantly enhanced tissue regeneration. Transcriptomic analysis further revealed the activation of immunomodulatory pathways and upregulation of M2-associated genes, confirming the system’s sequential shift from eradication to repair. Moreover, validation in a rabbit model and human knee joint confirmed its operational feasibility under clinical imaging guidance and excellent biosafety. This work establishes that integrating physical eradication, biochemical immunomodulation, and interactive control within a single system is essential for advancing from infection clearance to functional tissue restoration. Thus, it provides a therapeutic paradigm for biofilm-associated diseases and lays a foundation for future intelligent, clinically adaptive anti-infective systems.

Feeding health inequality through platform-based food delivery in China

This study examines how the expansion of online food delivery platforms affects health inequality in China. Exploiting the staggered rollout of platforms across counties and nationally representative panel data from 2010 to 2022, we find that platform entry increases overweight among low-income individuals while reducing it among high-income individuals. This divergence operates through two channels: low-income users increase consumption of fried foods and reallocate time from cooking to sedentary leisure, whereas high-income users reduce intake of calorie-dense foods and increase physical activity. These behavioral changes accumulate into downstream health consequences affecting weight-related chronic diseases and children's overweight in low-income households. Equal access to digital convenience thus does not translate into equal health benefits, suggesting that technological diffusion may amplify health disparities.

Reply to Huang and Dong: Clarifying the interpretation of rapid steroid effects in social recognition

Co-application of biochar and hydroxyapatite suppresses lead accumulation in rice via a soil–plant-microbe cascade

Distinguishing direct androgenic signaling from local aromatization in the lateral septum

Acceptance of a smartwatch-based clinical monitoring system in haemodialysis: A multicentre pilot implementation study of patients and nursing staff using an extended technology acceptance model

Abstract Smartwatch-based monitoring prototypes may support future haemodialysis care, but their implementation requires prior assessment of acceptability and feasibility. This study analysed acceptance of a clinical smartwatch designed to monitor physiological variables and support symptom communication among patients with chronic kidney disease undergoing haemodialysis, comparing patients and nursing staff through an extended Technology Acceptance Model. This was a multicentre pilot implementation study with a quantitative design based on an extended Technology Acceptance Model. A total of 137 participants were included: 83 patients with chronic kidney disease receiving haemodialysis and 54 nursing staff. Descriptive statistics, internal consistency analyses, and exploratory assessment of relationships between technology acceptance constructs were performed and interpreted cautiously given the pilot nature of the study. The smartwatch measurements were not clinically validated in this study, were not used for clinical decision-making, and were not integrated into the dialysis workflow. Both patients and nursing staff showed high levels of acceptance of the smartwatch, with positive attitudes and strong intentions to use the device. Among patients, perceived ease of use appeared more relevant to acceptance, whereas among nursing staff, perceived usefulness seemed to play a more prominent role. Overall, the findings suggest that acceptance patterns differed according to user role and clinical context. This pilot study suggests that a smartwatch-based monitoring prototype was generally well accepted by haemodialysis patients and nursing staff. However, the findings should be interpreted as evidence of acceptability and feasibility only, and not as evidence of clinical validity, clinical effectiveness, or workflow integration.

Functional traits produce conditional outcomes in different community contexts

Interfacial Schottky junction induced enhanced piezocatalytic activity

Identification and distribution of a downregulatory signaling alkyloxazole in <i> <i>Streptomyces</i> </i>

Streptomyces use small molecules to dictate morphological development and secondary metabolism. Most of these signaling compounds are inducers derived from γ-butyrolactone (GBL)-synthesizing enzymes. As such, biosynthetically distinct and downregulatory signaling molecules remain understudied in Streptomyces . Here, we report the identification of alkyloxaozle (AOX, 1 ), a downregulator of sporulation and antibiotic production in Streptomyces . 1 ’s structure features an oxazole head flanked by an alkyl tail synthesized by a nonribosomal peptide synthetase (NRPS) that has not been reported in Streptomyces signaling molecules. Functional studies found that 1 downregulated sporulation and secondary metabolism in several Streptomyces strains. Genome mining identified 45 homologous biosynthetic gene clusters (BGCs) only distributed in Streptomyces , underscoring the importance of AOXs to this productive genus. Altogether, this report presents a downregulatory class of signaling molecules that broadly affect Streptomyces and highlights their importance to the genus.

Evaluation of the grasp site after peeling of epiretinal membranes with different ILM forceps