Browse Articles

Numerical Fresnel models of Fresnel zone plates for plane wave at angle of incidence

How spatiotemporal dynamics can enhance ecosystem resilience

We study how self-organization in systems showing complex spatiotemporal dynamics can increase ecosystem resilience. We consider a general simple model that includes positive feedback as well as negative feedback mediated by an inhibitor. We apply this model to Posidonia oceanica meadows, where positive and negative feedbacks are well documented, and there is empirical evidence of the role of sulfide accumulation, toxic for the plant, in driving complex spatiotemporal dynamics. We describe a progressive transition from homogeneous meadows to extinction through dynamical regimes that allow the ecosystem to avoid the typical ecological tipping points of homogeneous vegetation covers. A predictable sequence of distinct dynamical regimes is observed as mortality is continuously increased: turbulent regimes, formation of spirals and wave trains, and isolated traveling pulses or expanding rings, the latter being a harbinger of ecosystem collapse, however far beyond the tipping point of the homogeneous cover. The model used in this paper is general, and the results can be applied to other plant–soil spatially extended systems, regardless of the mechanisms behind negative and positive feedbacks.

Real-world evidence provides clinical insights into tissue-agnostic therapeutic approvals

Author Correction: Evaluation of serum galectin-3 concentration as a potential biomarker in exudative-type age-related macular degeneration

A single-cell resolved genotype-phenotype map using genome-wide genetic and environmental perturbations

Abstract Heterogeneity is inherent to living organisms and it determines cell fate and phenotypic variability. Despite its ubiquity, the underlying molecular mechanisms and the genetic basis linking genotype to-phenotype heterogeneity remain a central challenge. Here we construct a yeast knockout library with a clone and genotype RNA barcoding structure suitable for genome-scale analyses to generate a high-resolution single-cell yeast transcriptome atlas of 3500 mutants under control and stress conditions. We find that transcriptional heterogeneity reflects the coordinated expression of specific gene programs, generating a continuous of cell states that can be responsive to external insults. Cell state plasticity can be genetically modulated with mutants that act as state attractors and disruption of state homeostasis results in decreased adaptive fitness. Leveraging on intra-genetic variability, we establish that regulators of transcriptional heterogeneity are functionally diverse and influenced by the environment. Our multimodal perturbation-based single-cell Genotype-to-Transcriptome Atlas in yeast provides insights into organism-level responses.

Publisher Correction: New geographic information system based sustainability metric for isolated photovoltaic systems

Guanine nucleotide biosynthesis blockade impairs MLL complex formation and sensitizes leukemias to menin inhibition

Abstract Targeting the dependency of MLL-rearranged (MLLr) leukemias on menin with small molecule inhibitors has opened new therapeutic strategies for these poor-prognosis diseases. However, the rapid development of menin inhibitor resistance calls for combinatory strategies to improve responses and prevent resistance. Here we show that leukemia stem cells (LSCs) of MLLr acute myeloid leukemia (AML) exhibit enhanced guanine nucleotide biosynthesis, the inhibition of which leads to myeloid differentiation and sensitization to menin inhibitors. Mechanistically, targeting inosine monophosphate dehydrogenase 2 (IMPDH2) reduces guanine nucleotides and rRNA transcription, leading to reduced protein expression of LEDGF and menin. Consequently, the formation and chromatin binding of the MLL-fusion complex is impaired, reducing the expression of MLL target genes. Inhibition of guanine nucleotide biosynthesis or rRNA transcription further suppresses MLLr AML when combined with a menin inhibitor. Our findings underscore the requirement of guanine nucleotide biosynthesis in maintaining the function of the LEDGF/menin/MLL-fusion complex and provide a rationale to target guanine nucleotide biosynthesis to sensitize MLLr leukemias to menin inhibitors.

VSS-SpatioNet: a multi-scale feature fusion network for multimodal image integrations

Probable evidence for a transient mega-electron volt emission line in the GRB 221023A

Mechanism and application of competitive fracture propagation in layered group fracturing of massive thick overburden strata

RGMb drives macrophage infiltration to aggravate kidney disease

The importance of macrophages in kidney diseases has been well established; however, the mechanisms underlying the infiltration of macrophages into injured kidneys are not well understood. RGMb is a member of the repulsive guidance molecule (RGM) family. RGMb can be expressed on the cell surface but a large portion of RGMb is localized intracellularly. Among various immune cell types, macrophages express the highest levels of RGMb, but the biological functions of RGMb in macrophages remain largely unknown. We find that RGMb promoted macrophage migration in vitro and that in vivo, RGMb enhanced infiltration of macrophages into injured kidneys and aggravated kidney inflammation and injury in mice. Mechanistically, RGMb bound to TAB1 inside the cell and facilitated the interaction between TRAF6 ubiquitin ligase and TAB1, thereby promoting TRAF6-mediated K63-linked polyubiquitination and phosphorylation of TAK1, followed by increased αTAT1 phosphorylation and α-tubulin acetylation. The resulting changes in the cytoskeleton promoted macrophage migration in vitro and in vivo. Deletion of Rgmb in macrophages markedly reduced TAK1 phosphorylation, αTAT1 phosphorylation, and α-tubulin acetylation and attenuated macrophage infiltration, renal inflammation, tubular injury, and interstitial fibrosis during kidney injury. Our results suggest that macrophage RGMb promotes kidney disease by increasing macrophage infiltration via the TRAF6-TAB1-TAK1/αTAT1/α-tubulin cascade.

Genomic structural variation in an alpha/beta hydrolase triggers hybrid necrosis in wheat

Production characteristics and adsorption control mechanism of CO2-rich CBG wells

Topologically reconfigurable nematic emulsions

In emulsions of multicomponent fluids, the dispersed phase forms tiny droplets in the continuous phase. In situ control and manipulation to achieve diversity in emulsion droplets for emerging applications is challenging. In a liquid crystal-based emulsion, the surface anchoring of the molecules at the isotropic fluid-liquid crystal interface introduces elastic distortions that result in anisotropic interparticle interactions, similar to electrostatic interactions between multipoles, which also lends a naming analogy as elastic dipoles, quadrupoles, and higher. However, controlling the anchoring condition at the interface at will is rarely achieved. Here, we present an emulsion system in which silicone oil droplets in a nematic liquid crystal spontaneously induce conic surface anchoring, forming elastic hexadecapoles without any surfactant. The conic degenerate surface anchoring shows continuous reversible anchoring transition to tangential and homeotropic below and above the ambient temperature, respectively. We introduce a physical design principle and in situ control to achieve three-phase compound droplets with diverse morphologies and topologies by fusing elastic hexadecapoles of oil droplets with elastic dipoles of glycerol droplets. The surrounding director field and the resulting defect structure of the compound droplets are analyzed by numerical simulations. Our approach to forming compound droplets will allow the on-demand design of building blocks for engineered emulsions for reconfigurable composite materials.

Ceramic-carbon Janus membrane for robust solar-thermal desalination

Abstract The desalination performance of conventional distillation membranes is limited by insufficient stability and energy efficiency, impeding their application in sustainable water production. Herein, we report a ceramic-carbon Janus membrane with solar-thermal functionality for enhanced desalination performance, energy efficiency, and stability for hypersaline water treatment. The feed and permeate sides of this Janus membrane are designed with different properties such as wettability, conductivity, and solar-thermal conversion to enhance performance. We demonstrate that this membrane exhibits higher solar-thermal efficiency (66.8–68.8%) and water flux (3.3–5.1 L m–2 h–1) than most existing polymeric solar-thermal distillation membranes. Simulation results ascribe enhanced performance to an increased membrane surface temperature, which mitigates temperature polarization and attenuation, thus enhancing the desalination driving force. The nano-carbon membrane surface accelerates water evaporation by inducing a transition from free water to intermediate water with decreased hydrogen bonding and a lower evaporation energy barrier. Water vapor molecules transport through the membrane pores by a combined mechanism of Knudsen diffusion and viscous flow. Even for seawater and hypersaline water, the membrane exhibits stable water flux and salt rejection due to its scaling-resistant surface and stable interfacial temperature. This work provides a strategy for rationally designing next-generation Janus membranes for sustainable water purification.

Multicenter study on the distribution and prevalence of human papillomavirus types in Hangzhou, Zhejiang from 2017 to 2023

The role of excitations in supercooled liquids: Density, geometry, and relaxation dynamics

Low-energy excitations play a key role in all condensed-matter systems, yet there is limited understanding of their nature in glasses, where they correspond to local rearrangements of groups of particles. Here, we introduce an algorithm to systematically uncover these excitations up to the activation energy scale relevant to structural relaxation. We use it in a model system to measure the density of states on a scale never achieved before, confirming that this quantity shifts to higher energy under cooling, precisely as the activation energy does. Second, we show that the excitations’ energetic and spatial features allow one to predict with great accuracy the dynamic propensity, i.e., the location of future relaxation dynamics. Finally, we find that excitations have a primary field whose properties, including the displacement of the most mobile particle, scale as a power-law of their activation energy and are independent of temperature. Additionally, they exhibit an outer deformation field that depends on the material’s stability and, therefore, on temperature. We build a scaling description of these findings. Overall, our analysis supports that excitations play a crucial role in regulating relaxation dynamics near the glass transition, effectively suppressing the transition to dynamical arrest predicted by mean-field theories while also being strongly influenced by it.

A phenopushing platform to identify compounds that alleviate acute hypoxic stress by fast-tracking cellular adaptation

Abstract Severe acute hypoxic stress is a major contributor to the pathology of human diseases, including ischemic disorders. Current treatments focus on managing consequences of hypoxia, with few addressing cellular adaptation to low-oxygen environments. Here, we investigate whether accelerating hypoxia adaptation could provide a strategy to alleviate acute hypoxic stress. We develop a high-content phenotypic screening platform to identify compounds that fast-track adaptation to hypoxic stress. Our platform captures a high-dimensional phenotypic hypoxia response trajectory consisting of normoxic, acutely stressed, and chronically adapted cell states. Leveraging this trajectory, we identify compounds that phenotypically shift cells from the acutely stressed state towards the adapted state, revealing mTOR/PI3K or BET inhibition as strategies to induce this phenotypic shift. Importantly, our compound hits promote the survival of liver cells exposed to ischemia-like stress, and rescue cardiomyocytes from hypoxic stress. Our “phenopushing” platform offers a general, target-agnostic approach to identify compounds and targets that accelerate cellular adaptation, applicable across various stress conditions.

A hybrid re-fusion model for text classification

Brain-wide dynamic coactivation states code for hand movements in the resting state

Resting brain activity, in the absence of explicit tasks, appears as distributed spatiotemporal patterns that reflect structural connectivity and correlate with behavioral traits. However, its role in shaping behavior remains unclear. Recent evidence shows that resting-state spatial patterns not only align with task-evoked topographies but also encode distinct visual (e.g., lines, contours, faces, places) and motor (e.g., hand postures) features, suggesting mechanisms for long-term storage and predictive coding. While prior research focused on static, time-averaged task activations, we examine whether dynamic, time-varying motor states seen during active hand movements are also present at rest. Three distinct motor activation states, engaging the motor cortex alongside sensory and association areas, were identified. These states appeared both at rest and during task execution but underwent temporal reorganization from rest to task. Thus, resting-state dynamics serve as strong spatiotemporal priors for task-based activation. Critically, resting-state patterns more closely resembled those associated with frequent ecological hand movements than with an unfamiliar movement, indicating a structured repertoire of movement patterns that is replayed at rest and reorganized during action. This suggests that spontaneous neural activity provides priors for future movements and contributes to long-term memory storage, reinforcing the functional interplay between resting and task-driven brain activity.