Browse Articles

Topological phononic switch based on reconfigurable symmetry-broken crystals with rotatable scatterers

Unveiling the cell-type-specific landscape of cellular senescence through single-cell transcriptomics using SenePy

Abstract Senescent cells accumulate in most tissues with organismal aging, exposure to stressors, or disease progression. It is challenging to identify senescent cells because cellular senescence signatures and phenotypes vary widely across distinct cell types and tissues. Here we developed an analytical algorithm that defines cell-type-specific and universal signatures of cellular senescence across a wide range of cell types and tissues. We utilize 72 mouse and 64 human weighted single-cell transcriptomic signatures of cellular senescence to create the SenePy scoring platform. SenePy signatures better recapitulate in vivo cellular senescence than signatures derived from in vitro senescence studies. We use SenePy to map the kinetics of senescent cell accumulation in healthy aging as well as multiple disease contexts, including tumorigenesis, inflammation, and myocardial infarction. SenePy characterizes cell-type-specific in vivo cellular senescence and could lead to the identification of genes that serve as mediators of cellular senescence and disease progression.

Identifying signatures of past and present cryovolcanism on Europa

Abstract Europa, the most visibly active icy moon of Jupiter, is a prime target for the search for life in the outer solar system. Two spacecraft missions, Europa Clipper from the National Aeronautics and Space Administration (NASA) and the Jupiter Icy Moon Explorer (JUICE) from the European Space Agency (ESA), will observe its surface, probe its interior structure, and characterize the space environment starting in 2030. Occasional eruptions of water sourced from Europa’s interior may provide a window on the interior conditions and habitability of the moon. Here, we investigate the storage and evolution of briny water in Europa’s ice shell and propose a framework to interpret spectral, thermal, radar and gravity data collected by future missions. We show that it is possible to discriminate between water erupting from the deep ocean or from shallow liquid reservoirs using combined measurements of the material’s salinity, surface temperature and ice shell thickness.

Universal in situ oxide-based ABX3-structured seeds for templating halide perovskite growth in All-perovskite tandems

Abstract Precise control over halide perovskite crystallization is pivotal for realizing efficient solar cells. Here, we introduce a strategy utilizing in-situ-formed oxide-based ABX3-structured seeds to regulate perovskite crystallization and growth. Introducing potassium stannate into perovskite precursors triggers a spontaneous reaction with lead iodide, producing potassium iodide and lead stannate. Potassium iodide effectively passivates defects, while PbSnO3 (ABX3-structured), exhibiting a 98% lattice match, acts as a template and seed. This approach facilitates pre-nucleation cluster formation, preferential grain orientation, and the elimination of intermediate-phase processes in perovskite films. Incorporating potassium stannate into both the perovskite precursors and the buried hole transport layers enables single-junction 1.25 eV-bandgap Sn-Pb perovskite solar cells to achieve a steady-state efficiency of 23.12% and enhanced stability. Furthermore, all-perovskite tandem devices yield efficiencies of 28.12% (two-terminal) and 28.81% (four-terminal). This versatile templating method also boosts the performance of 1.77 eV and 1.54 eV-bandgap cells, underscoring its broad applicability.

The role of Tyr34 in proton coupled electron transfer and product inhibition of manganese superoxide dismutase

Anomalous δ15N values in the Neoarchean associated with an abundant supply of hydrothermal ammonium

Abstract Unusually high δ15N values in the Neoarchean sedimentary record in the time period from 2.8 to 2.6 Ga, termed the Nitrogen Isotope Event (NIE), might be explained by aerobic N cycling prior to the Great Oxidation Event (GOE). Here we report strongly positive δ15N values up to +42.5 ‰ in ~2.75 – 2.73 Ga shallow-marine carbonates from Zimbabwe. As the corresponding deeper-marine shales exhibit negative δ15N values that are explained by partial biological uptake from a large ammonium reservoir, we interpret our data to have resulted from hydrothermal upwelling of 15N-rich ammonium into shallow, partially oxic waters, consistent with uranium isotope variations. This work shows that anomalous N isotope signatures at the onset of the NIE temporally correlate with extensive volcanic and hydrothermal activity both locally and globally, which may have stimulated primary production and spurred biological innovation in the lead-up to the GOE.

Low-temperature pressure-assisted liquid-metal printing for β-Ga2O3 thin-film transistors

Abstract Developing a low-temperature and cost-effective manufacturing process for energy-efficient and high-performance oxide-thin-film transistors (TFTs) is a crucial step toward advancing next-generation device applications such as wearable and flexible electronics. Among several methods, a liquid-metal printing technique is considered a promising, cost-effective oxide semiconductor process due to its inherent advantages, such as vacuum-free, low-thermal budget, high throughput, and scalability. In this study, we have developed a pressure-assisted liquid-metal printing technique enabling the low-temperature synthesis of polycrystalline wide bandgap n-channel oxide-TFTs. The n-channel oxide TFTs based on ~3 nm-thick β-Ga2O3 channels exhibited good TFT switching properties with a threshold voltage of ~3.8 V, a saturation mobility of ~11.7 cm2 V−1 s−1, an on/off-current ratio of ~109, and a subthreshold slope of ~163 mV/decade. We also observed p-channel operation in the off-stoichiometric GaOx channels fabricated at high-pressure conditions. Toward oxide-based circuit applications, we developed high-performance oxide-TFT-based inverters. While our approach can promote the advancement of low-temperature manufacturing for oxide TFT technology, further work will be necessary to confirm the role of the applied pressure in the β-Ga2O3 crystallization process.

Cold spells over Greenland during the mid-Pliocene Warm Period

Abstract The mid-Pliocene Warm Period (mPWP; 3.26–3.02 Ma) is an interval often suggested as a potential analogue of the near future climate and fate of the Greenland Ice Sheet (GIS). Here, neodymium and lead isotopes from marine sediment cores collected off the southern Greenland margin suggest pulses of intense glacial erosion of Precambrian terranes during this interval, while grain size data indicate a reduction in the strength of contour currents, both following a near obliquity cycle (~41 ka) pacing. These cold spells were thus sufficiently intense to trigger recurrent ice growth over Greenland, even under the high atmospheric CO 2 concentration (~400 ppmV) of the interval, before the intensification of the Northern Hemisphere Glaciation (~2.7 Ma). However, the mPWP was marked by a low amplitude in the axial tilt oscillation of the Earth, thus lesser variations in summer insolation at high latitudes than in the present era. Therefore, although it may offer some similarities with the future of the Earth’s climate, the mid-Pliocene cannot be seen as a genuine analogue for predicting the fate of the GIS.

Spatial recognition and semi-quantification of epigenetic events in pancreatic cancer subtypes with multiplexed molecular imaging and machine learning

Abstract Genomic alterations are the driving force behind pancreatic cancer (PC) tumorigenesis, but they do not fully account for its diverse phenotypes. Investigating the epigenetic landscapes of PC offers a more comprehensive understanding and could identify targeted therapies that enhance patient survival. In this study, we have developed a new promising methodology of spatial epigenomics that integrates multiplexed molecular imaging with convolutional neural networks. Then, we used it to map epigenetic modification levels in the six most prevalent PC subtypes. We analyzed and semi-quantified the resulting molecular data, revealing significant variability in their epigenomes. DNA and histone modifications, specifically methylation and acetylation, were investigated. Using the same technique, we examined DNA conformational changes to further elucidate the transcriptional regulatory mechanisms involved in PC differentiation. Our results revealed that the foamy-gland and squamous-differentiated subtypes exhibited significantly increased global levels of epigenetic modifications and elevated Z-DNA ratios. Overall, our findings may suggest a potentially reduced efficacy of therapeutics targeting epigenetic regulators for these subtypes. Conversely, the conventional ductal PC subtype has emerged as a promising candidate for treatment with epigenetic modulators.

Cationic-anionic synchronous ring-opening polymerization

Association between niacin intake and osteoarthritis in the US population based on NHANES 1999–2018

Online test-time adaptation for better generalization of interatomic potentials to out-of-distribution data

Droplet impact dynamics on stretched textiles

Abstract Preventing droplets from penetrating fabrics is critical in surgical wards and the battlefield, where biological and chemical hazards are dispersed and transmitted in droplet form. Here, we study the interaction between droplets and a nylon textile using high-speed imaging. We explore various droplet impact velocities and liquids to understand the influence of liquid characteristics on the impact behaviour. Importantly, we investigate the impact dynamics of droplets on textiles subjected to various tensile forces. Critical phenomena, such as droplet penetration and capture, are analyzed. We find that the critical impact velocity for droplet penetration increases as the stretching tension in the textile decreases. Furthermore, we present a simple model to predict the critical conditions for droplet penetration and capture that takes into account the surface tension, the droplet size, density and speed, the tensile load and the textile contact angle. We validate the model through experiments, demonstrating a strong agreement. These insights hold significant implications for the design of protective garments, such as face-masks and water-repellent clothing.

Event-driven figure-ground organisation model for the humanoid robot iCub

A distributed task allocation approach for multi-UAV persistent monitoring in dynamic environments

EccDNA atlas in male mice reveals features protecting genes against transcription-induced eccDNA formation

Body mass index and head circumference growth charts for the United Arab Emirates-the UAEMCGS 2 study

Phage parasites targeting phage homologous recombinases provide antiviral immunity

Abstract Bacteria often carry multiple genes encoding anti-phage defense systems, clustered in defense islands and phage satellites. Various unrelated anti-phage defense systems target phage-encoded homologous recombinases (HRs) through unclear mechanisms. Here, we show that the phage satellite SaPI2, which does not encode orthodox anti-phage defense systems, provides antiviral immunity mediated by Stl2, the SaPI2-encoded transcriptional repressor. Stl2 targets and inhibits phage-encoded HRs, including Sak and Sak4, two HRs from the Rad52-like and Rad51-like superfamilies. Remarkably, apo Stl2 forms a collar of dimers oligomerizing as closed rings and as filaments, mimicking the quaternary structure of its targets. Stl2 decorates both Sak rings and Sak4 filaments. The oligomerization of Stl2 as a collar of dimers is necessary for its inhibitory activity both in vitro and in vivo. Our results shed light on the mechanisms underlying antiviral immunity against phages carrying divergent HRs.

Association between adverse childhood experiences with chronic kidney diseases in middle-aged and older adults in mainland China

Activation of CAMK2 by pseudokinase PEAK1 represents a targetable pathway in triple negative breast cancer

Abstract The PEAK family of pseudokinases, comprising PEAK1-3, play oncogenic roles in several poor prognosis human cancers, including triple negative breast cancer (TNBC). However, therapeutic targeting of pseudokinases is challenging due to their lack of catalytic activity. To address this, we screen for PEAK1 effectors and identify calcium/calmodulin-dependent protein kinase 2 (CAMK2)D and CAMK2G. PEAK1 promotes CAMK2 activation in TNBC cells via PLCγ1/Ca 2+ signalling and direct binding to CAMK2. In turn, CAMK2 phosphorylates PEAK1 to enhance association with PEAK2, which is critical for PEAK1 oncogenic signalling. To achieve pharmacologic targeting of PEAK1/CAMK2, we repurpose RA306, a second generation CAMK2 inhibitor. RA306 inhibits PEAK1-enhanced migration and invasion of TNBC cells in vitro and significantly attenuates TNBC xenograft growth and metastasis in a manner mirrored by PEAK1 ablation. Overall, these studies establish PEAK1 as a critical cell signalling nexus that integrates Ca 2+ and tyrosine kinase signals and identify CAMK2 as a therapeutically ‘actionable’ target downstream of PEAK1.